What can we learn with nuclear physics?
Nuclear Physics Institute of the Czech Academy of Sciences
Primary focus of the institute is nuclear physics, both theoretical and experimental. It carries out studies in the nuclear spectroscopy of beta and gamma radiation, nuclear reactions including the collisions of heavy ions and hyper-nuclear physics. Its work is also focused on related fields, such as the study of the solid phase using neutron scattering, mathematical physics and theoretical subnuclear physics.Isochronous cyclotron U-120M is the primary experimental facility of the institute and it is the only cyclotron in the Czech Republic. It has been operating since 1977. The cyclotron is used both for fundamental research and applications. It can accelerate ions within the range of the mass-to-charge ratio A/q = 1 - 2.8. The present internal radial ion source is suitable for acceleration of H^+, D^+, 4-He^+2 and 3-He^+2. Maximum proton energy is 36 MeV, and the maximum energy for heavier ions is given by 40 q^2/A MeV. Currents of an internal beam of protons and deuterons can reach 100 microA, and for extracted beams 5 microA. Particles are extracted from the cyclotron chamber by means of a 3-section deflection electrostatic system to the entrance of the beam lines.
Joint Institute for Nuclear Astrophysics
Nuclear astrophysics is made of many overlapping disciplines, spanning fields in Astronomy, Astrophysics and Nuclear Physics. In order to understand the origin of the elements, or the evolution and deaths of stars in galaxies, quite a broad base of knowledge is required. JINA-CEE created two virtual journals in order to meet the need for coverage of this broad-based information. The JINA Virtual Journal debuted in 2003, and reviews a broad realm of nuclear astrophysics, followed by the SEGUE Virtual Journal in 2006, focusing more on Galactic Chemical and Structural evolution. Each week, the editors search almost 40 refereed journals for newly published articles. Editors review the articles, flagging those that are relevant, and categorize them into their respective subjects (which are searchable by individual users). When the virtual journals are published, an email notification is sent to subscribers informing them of the newly available selections from the Virtual Journals.
Nuclear fission
During this period the Hungarian physicist Leó Szilárd, who was residing in the United States at the time, realized that the neutron-driven fission of heavy atoms could be used to create a nuclear chain reaction. Such a reaction using neutrons was an idea he had first formulated in 1933, upon reading Rutherford's disparaging remarks about generating power from his team's 1932 experiment using protons to split lithium. However, Szilárd had not been able to achieve a neutron-driven chain reaction with neutron-rich light atoms. In theory, if in a neutron-driven chain reaction the number of secondary neutrons produced was greater than one, then each such reaction could trigger multiple additional reactions, producing an exponentially increasing number of reactions. It was thus a possibility that the fission of uranium could yield vast amounts of energy for civilian or military purposes (i.e., electric power generation or atomic bombs).
Outline of nuclear power
Nuclear power – the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity.
List of technology in the Dune universe
Atomics is the term used to refer to nuclear weapons in the "Dune" universe. Like real-world nuclear weapons, atomics presumably derive their destructive force from nuclear reactions of fission or fusion, and Herbert notes that "radiation lingers" after their use. However, the author never delves into the specifics of the technology or explores in detail how it may have evolved by the time of "Dune"'s far-future setting.
Nuclear ethics
Nuclear ethics is a cross-disciplinary field of academic and policy-relevant study in which the problems associated with nuclear warfare, nuclear deterrence, nuclear arms control, nuclear disarmament, or nuclear energy are examined through one or more ethical or moral theories or frameworks. In contemporary security studies, the problems of nuclear warfare, deterrence, proliferation, and so forth are often understood strictly in political, strategic, or military terms. In the study of international organizations and law, however, these problems are also understood in legal terms. Nuclear ethics assumes that the very real possibilities of human extinction, mass human destruction, or mass environmental damage which could result from nuclear warfare are deep ethical or moral problems. Specifically, it assumes that the outcomes of human extinction, mass human destruction, or environmental damage count as moral evils. Another area of inquiry concerns future generations and the burden that nuclear waste and pollution imposes on them. Some scholars have concluded that it is therefore morally wrong to act in ways that produce these outcomes, which means it is morally wrong to engage in nuclear warfare.
Physics education
In most introductory physics courses mechanics usually is the first area of physics that is discussed, and Newton's laws of motion, which describe how massive objects respond to forces, are central to the study of mechanics. As an example, many students hold the aristotelian misconception that a net force is required to keep a body moving; instead, motion is modelled in modern physics with the Newton's First Law of inertia, stating that a body will keep its state of rest or movement unless a net force acts on the body. Newton arrived at his three laws of motion from an extensive study of empirical data including many astronomical observations. In an active learning environment students might experiment with objects in an environment that has almost no friction, for example a block moving on an almost frictionless air table. There they would find that if they start the block moving at constant speed, it continues to move at constant speed without the need for a constant "push". It is hoped that exercises of this nature will help students to overcome their preconceived ideas about motion.
Fundamental interaction
After the nucleus was discovered in 1908, it was clear that a new force, today known as the nuclear force, was needed to overcome the electrostatic repulsion, a manifestation of electromagnetism, of the positively charged protons. Otherwise, the nucleus could not exist. Moreover, the force had to be strong enough to squeeze the protons into a volume whose diameter is about 10 m, much smaller than that of the entire atom. From the short range of this force, Hideki Yukawa predicted that it was associated with a massive particle, whose mass is approximately 100 MeV.
Nuclear force
The nuclear force is powerfully attractive between nucleons at distances of about 1 femtometre (fm, or 1.0 × 10 metres), but it rapidly decreases to insignificance at distances beyond about 2.5 fm. At distances less than 0.7 fm, the nuclear force becomes repulsive. This repulsive component is responsible for the physical size of nuclei, since the nucleons can come no closer than the force allows. By comparison, the size of an atom, measured in angstroms (Å, or 1.0 × 10 m), is five orders of magnitude larger. The nuclear force is not simple, however, since it depends on the nucleon spins, has a tensor component, and may depend on the relative momentum of the nucleons. The strong nuclear force is one of the fundamental forces of nature.
Ross Gunn
The 1938 discovery of nuclear fission aroused great interest among physicists. On March 17, 1939, Enrico Fermi gave a presentation to the Navy on the state of nuclear research, and the possibility of the development of atomic bombs and nuclear power. Gunn was in attendance as the NRL representative. Gunn was impressed by the possibility of utilizing nuclear power to propel ships, particularly submarines, as nuclear power would not require oxygen. On March 20, Gunn and the director of the NRL, Captain Hollis M. Cooley, approached Rear Admiral Harold G. Bowen, Sr., the head of the Bureau of Engineering, which controlled funding for the NRL, with a request for $1,500 for research into uranium. This was approved; the Navy's program predated the Army's Manhattan Project by seven months.
Atomic spies
Before World War II, the theoretical possibility of nuclear fission occasioned intense discussion among leading physicists world-wide. Scientists from the Soviet Union were later recognized for their contributions to the understanding of a nuclear reality, and won several Nobel Prizes. Soviet scientists such as Igor Kurchatov, L. D. Landau, and Kirill Sinelnikov helped establish the idea of, and prove the existence of, a splittable atom. Dwarfed by the Manhattan Project, the significance of the Soviet contributions is rarely understood or credited outside of the field of physics. According to several sources, it was understood on a theoretical level that the atom provided for extremely powerful and novel releases of energy, and could possibly be utilized in the future for military purposes. In recorded comments, the physicists lamented their inability to achieve any kind of practical application from the discoveries. This would show that the scientists thought the creation of an atomic weapon was a pipe-dream and unattainable. According to a United States Congressional joint committee, although the scientists could conceivably have been first to generate a man-made fission reaction, in reality they lacked the ambition, funding, engineering capability, leadership, and ultimately, the capability to do so. The undertaking would be of an unimaginable scale, and the resources required to engineer for such use as a nuclear bomb, and nuclear power were deemed too great to pursue.
Nuclear peace
Nuclear peace is a theory of international relations that argues that under some circumstances nuclear weapons can induce stability and decrease the chances of crisis escalation. In particular, nuclear weapons are said to have induced stability during the Cold War, when both the US and the USSR possessed mutual second strike retaliation capability, eliminating the possibility of nuclear victory for either side. Proponents of nuclear peace argue that controlled nuclear proliferation may be beneficial for inducing stability. Critics of nuclear peace argue that nuclear proliferation not only increases the chance of interstate nuclear conflict, but increases the chances of nuclear material falling into the hands of violent non-state groups who are free from the threat of nuclear retaliation.
Power to Save the World
Power to Save the World: The Truth About Nuclear Energy (Knopf, 2007), by Gwyneth Cravens, is an introduction to the benefits of nuclear power and the science behind it. It is written for members of the lay public who want to learn more about nuclear power, environmentalists concerned about global warming due to fossil fuel combustion; and scientists and others who work in the nuclear world.
Nuclear structure
The independent particle model and mean field theories (we shall see that there exist several variants) have a great success in describing the properties of the nucleus starting from an effective interaction or an effective potential, thus are a basic part of atomic nucleus theory. One should also notice that they are modular enough, in that it is quite easy to extend the model to introduce effects such as nuclear pairing, or collective motions of the nucleon like rotation, or vibration, adding the corresponding energy terms in the formalism. This implies that in many representations, the mean field is only a starting point for a more complete description which introduces correlations reproducing properties like collective excitations and nucleon transfer.
Nuclear technology
In natural nuclear radiation, the byproducts are very small compared to the nuclei from which they originate. Nuclear fission is the process of splitting a nucleus into roughly equal parts, and releasing energy and neutrons in the process. If these neutrons are captured by another unstable nucleus, they can fission as well, leading to a chain reaction. The average number of neutrons released per nucleus that go on to fission another nucleus is referred to as "k". Values of "k" larger than 1 mean that the fission reaction is releasing more neutrons than it absorbs, and therefore is referred to as a self-sustaining chain reaction. A mass of fissile material large enough (and in a suitable configuration) to induce a self-sustaining chain reaction is called a critical mass.
Nuclear force
The nuclear force is a residual effect of the more fundamental strong force, or strong interaction. The strong interaction is the attractive force that binds the elementary particles called quarks together to form the nucleons (protons and neutrons) themselves. This more powerful force is mediated by particles called gluons. Gluons hold quarks together through color charge which is analogous to electric charge, but far stronger. Quarks, gluons, and their dynamics are mostly confined within nucleons, but residual influences extend slightly beyond nucleon boundaries to give rise to the nuclear force.
Amory Lovins
Lovins general assessment of nuclear power is that "Nuclear power is the only energy source where mishap or malice can kill so many people so far away; the only one whose ingredients can help make and hide nuclear bombs; the only climate solution that substitutes proliferation, accident, and high-level radioactive waste dangers. Indeed, nuclear plants are so slow and costly to build that they reduce and retard climate protection". With respect to the 2011 Japanese nuclear accidents, Lovins has said: "An earthquake-and-tsunami zone crowded with 127 million people is an unwise place for 54 reactors".
Nuclear engineering
Nuclear engineering is the branch of engineering concerned with the application of breaking down atomic nuclei (fission) or of combining atomic nuclei (fusion), or with the application of other sub-atomic processes based on the principles of nuclear physics. In the sub-field of nuclear fission, it particularly includes the design, interaction, and maintenance of systems and components like nuclear reactors, nuclear power plants, or nuclear weapons. The field also includes the study of medical and other applications of radiation, particularly Ionizing radiation, nuclear safety, heat/thermodynamics transport, nuclear fuel, or other related technology (e.g., radioactive waste disposal) and the problems of nuclear proliferation.
Munir Ahmad Khan
Since the 1940s, Munir Khan and the Nobel Laureate in Physics, Professor Abdus Salam were associates who studied Physics and Mathematics together at Government College, Lahore. Khan recognised the importance of Theoretical physics, and had studied its "real world" applications that related to the field of nuclear engineering, whilst trying to solve the reactor physics problems. During 1967, he and Salam prepared a proposal for setting up a nuclear fuel and plutonium reprocessing plant in Pakistan, which was deferred by President Field Marshal Ayub Khan on economic grounds.
International Nathiagali Summer College on Physics
The institution is noted for its high-powered research in particle physics, nuclear physics, theoretical physics, astrophysics, nanotechnology, nuclear technology, Semiconductor physics, superconductor, general relativity, polymer physics, experimental physics, molecular physics, atomic physics, laser physics, cosmology and research on nuclear and particle detectors. The institution also host lectures in different fields of science and mathematics
Nuclear force
Two-nucleon systems such as the deuteron, the nucleus of a deuterium atom, as well as proton–proton or neutron–proton scattering are ideal for studying the "NN" force. Such systems can be described by attributing a "potential" (such as the Yukawa potential) to the nucleons and using the potentials in a Schrödinger equation. The form of the potential is derived phenomenologically (by measurement), although for the long-range interaction, meson-exchange theories help to construct the potential. The parameters of the potential are determined by fitting to experimental data such as the deuteron binding energy or "NN" elastic scattering cross sections (or, equivalently in this context, so-called "NN" phase shifts).
Homeokinetics
Ordinary physics is a flatland physics, a physics at some particular level. Examples include nuclear and atomic physics, biophysics, social physics, and stellar physics. Homeokinetic physics combines flatland physics with the study of the up down processes that binds the levels. Tools, such as mechanics, quantum field theory, and the laws of thermodynamics, provide key relationships for the binding of the levels, how they connect, and how the energy flows up and down. And whether the atomisms are atoms, molecules, cells, people, stars, galaxies, or universes, the same tools can be used to understand them. Homeokinetics treats all complex systems on an equal footing, animate and inanimate, providing them with a common viewpoint. The complexity in studying how they work is reduced by the emergence of common languages in all complex systems.
Nuclear Power and the Environment
The focus of the first half of the chapter is designed to provide basic information about atoms and radiation to aid in later chapters. The first half covers the basics on atoms such as: an atom consists of Neutrons, Protons, and Electrons; the atomic number of an atom determines the amount of protons in one atom; and that protons are roughly 2000 times heavier than electrons (see atom). The concept of radiation is introduced through ionization which is the process of adding one or more electrons to, or removing one or more electrons from, atoms or molecules, thereby creating ions. From there certain particles can cause ionization. The ionizing particles are alpha particles (a type of ionizing radiation ejected by the nuclei of some unstable atoms that are large subatomic fragments consisting of two protons and two neutrons), beta particles (subatomic particles ejected from the nucleus of some radioactive atoms that are equivalent to electrons), gamma particles (electromagnetic energy photon) and energetic neutron radiation (energy released from an atom in the form of neutral particles called neutrons). The second half focuses on knowledge of radiation introduced into the environment and humans. Flower's and his team concluded in 1976 that low levels over a long exposure time can prevent a cell from dividing or further damaging genetic information.
Other topics covered are the effects of plutonium in the body. For instance, animals being susceptible to radiation causes birth defects among the litter. Chapter two concludes with a concern of radiation affecting an entire species of animals as opposed to a group.
Nuclear binding energy
An example that illustrates nuclear binding energy is the nucleus of C (carbon-12), which contains 6 protons and 6 neutrons. The protons are all positively charged and repel each other, but the nuclear force overcomes the repulsion and causes them to stick together. The nuclear force is a close-range force (it is strongly attractive at a distance of 1.0 fm and becomes extremely small beyond a distance of 2.5fm), and virtually no effect of this force is observed outside the nucleus. The nuclear force also pulls neutrons together, or neutrons and protons.
Nuclear power
Just as many conventional thermal power stations generate electricity by harnessing the thermal energy released from burning fossil fuels, nuclear power plants convert the energy released from the nucleus of an atom via nuclear fission that takes place in a nuclear reactor. When a neutron hits the nucleus of a uranium-235 or plutonium atom, it can split the nucleus into two smaller nuclei. The reaction is called nuclear fission. The fission reaction releases energy and neutrons. The released neutrons can hit other uranium or plutonium nuclei, causing new fission reactions, which release more energy and more neutrons. This is called a chain reaction. The reaction rate is controlled by control rods that absorb excess neutrons. The controllability of nuclear reactors depends on the fact that a small fraction of neutrons resulting from fission are delayed. The time delay between the fission and the release of the neutrons slows down changes in reaction rates and gives time for moving the control rods to adjust the reaction rate.
Nuclear physics
The history of nuclear physics as a discipline distinct from atomic physics starts with the discovery of radioactivity by Henri Becquerel in 1896, while investigating phosphorescence in uranium salts. The discovery of the electron by J. J. Thomson a year later was an indication that the atom had internal structure. At the beginning of the 20th century the accepted model of the atom was J. J. Thomson's "plum pudding" model in which the atom was a positively charged ball with smaller negatively charged electrons embedded inside it.
Igal Talmi
Talmi's main field of research is the theory of nuclear structure. The atomic nucleus is composed of a large number of protons and neutrons which move due to strong interactions between them. In spite of their complexity, nuclei exhibit some simple and regular features. Most importantly, nuclei behave as if they move independently in a common static potential well. This gives rise to the existence of shells of protons and neutrons much like the electronic shells in atoms. Nuclei whose proton and neutron shells are complete have special stability and the numbers of protons and of neutrons in them are called magic numbers. This picture of the nucleus is called the nuclear shell model to obtain the information from experimental data and use it to calculate and predict energies which have not been measured. This method has been successfully used by many nuclear physicists and has led to deeper understanding of nuclear structure. To calculate energies of nuclear states it is necessary to know the exact form of the forces which act between the nuclear constituents. These are still not sufficiently known even after many years of research. Talmi developed a method to obtain the information from experimental data and use it to calculate and predict energies which have not been measured. This method has been successfully used by many nuclear physicists and has led to deeper understanding of nuclear structure.
The theory which gives a good description of these properties was developed. This description turned out to furnish the shell model basis of the elegant and successful interacting boson models.
Talmi also participated in the study of explicit
fermion–boson mappings required to connect the interacting-boson model with its shell-model
roots and in the introduction of the boson F-spin analog to nucleon isospin.
Internet streaming broadcasting both on WM and QT (at 64k bps, 256 kbit/s, 1M bps) and DVD ISO (NTSC and PAL) delivery are now available at RIKEN Nishina Center.
Nuclear shell model
In nuclear physics and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels. The first shell model was proposed by Dmitry Ivanenko (together with E. Gapon) in 1932. The model was developed in 1949 following independent work by several physicists, most notably Eugene Paul Wigner, Maria Goeppert Mayer and J. Hans D. Jensen, who shared the 1963 Nobel Prize in Physics for their contributions.
Nuclear warfare
To avoid injury and death from a nuclear weapons heat flash and blast effects, the two most far ranging prompt effects of nuclear weapons, schoolchildren were taught to duck and cover by the early Cold War film of the same name. Such advice is once again being given in case of nuclear terrorist attacks.
Power plant engineering
Nuclear engineers develops and research methods, machinery and systems concerning radiation and energy in subatomic levels. They require on-site experience and a bachelor's degree in Engineering. These engineers work in Nuclear Power plants and require licenses for practice while working in the power plant. They require work experience, passing the Professional Engineering Exam(PE), Fundamental Engineering Exam (FE), and a degree from an Accreditation Board for Engineering and Technology, Inc (ABET) approved school. Nuclear engineers work with the handling of nuclear material and operations of a nuclear power plant. These operations can range from handling of nuclear wastes, nuclear material experiments, and design of nuclear equipment.
Nuclear physics
In 1935 Hideki Yukawa proposed the first significant theory of the strong force to explain how the nucleus holds together. In the Yukawa interaction a virtual particle, later called a meson, mediated a force between all nucleons, including protons and neutrons. This force explained why nuclei did not disintegrate under the influence of proton repulsion, and it also gave an explanation of why the attractive strong force had a more limited range than the electromagnetic repulsion between protons. Later, the discovery of the pi meson showed it to have the properties of Yukawa's particle.
Nuclear physics
The study of the strong and weak nuclear forces (the latter explained by Enrico Fermi via Fermi's interaction in 1934) led physicists to collide nuclei and electrons at ever higher energies. This research became the science of particle physics, the crown jewel of which is the standard model of particle physics which describes the strong, weak, and electromagnetic forces.
Neutron
By 1934, Fermi had bombarded heavier elements with neutrons to induce radioactivity in elements of high atomic number. In 1938, Fermi received the Nobel Prize in Physics ""for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons"". In 1938 Otto Hahn, Lise Meitner, and Fritz Strassmann discovered nuclear fission, or the fractionation of uranium nuclei into light elements, induced by neutron bombardment. In 1945 Hahn received the 1944 Nobel Prize in Chemistry ""for his discovery of the fission of heavy atomic nuclei."" The discovery of nuclear fission would lead to the development of nuclear power and the atomic bomb by the end of World War II.
Nuclear power
In August 1945, the first widely distributed account of nuclear energy, in the form of the pocketbook "The Atomic Age", discussed the peaceful future uses of nuclear energy and depicted a future where fossil fuels would go unused.
Nobel laureate Glenn Seaborg, who later chaired the Atomic Energy Commission, is quoted as saying "there will be nuclear powered earth-to-moon shuttles, nuclear powered artificial hearts, plutonium heated swimming pools for SCUBA divers, and much more".
RAON
Research areas in the field of nuclear science include the study of the origin of elements and evolution of stars, nuclear force and structure, nuclear reactions, and nuclear science theory.
Nuclear power debate
Nuclear power plants are a complex energy system and opponents of nuclear power have criticized the sophistication and complexity of the technology. Helen Caldicott has said: "... in essence, a nuclear reactor is just a very sophisticated and dangerous way to boil water – analogous to cutting a pound of butter with a chain saw." The 1979 Three Mile Island accident inspired Charles Perrow's book "Normal Accidents", where a nuclear accident occurs, resulting from an unanticipated interaction of multiple failures in a complex system. TMI was an example of a normal accident because it was deemed "unexpected, incomprehensible, uncontrollable and unavoidable".
Ivan Aničin
At University of Belgrade, professor Aničin teaches or had taught the following subjects: Data Treatment in Physics, Order of Magnitude Physics, various courses of Nuclear Physics, Nuclear and Elementary Particle Physics, Foundations of Nuclear and Particle Physics, Higher Course in Nuclear Physics, Nuclear Instrumentation, Nuclear Spectroscopy, Selected Chapters of High Energy Physics, Detectors, Nondestructive Analysis, Rare Subatomic Processes, Astroparticle Physics, Radiation Physics.
Nuclear force
Our understanding of the nuclear force is obtained by scattering experiments and the binding energy of light nuclei.
The nuclear force occurs by the exchange of virtual light mesons, such as the virtual pions, as well as two types of virtual mesons with spin (vector mesons), the rho mesons and the omega mesons. The vector mesons account for the spin-dependence of the nuclear force in this "virtual meson" picture.
Advanced Simulation and Computing Program
The Physics and Engineering Models subdivision is responsible for deciphering the mathematical and physical analysis of nuclear weapons. They integrate physics models into the codes in order to gain a more accurate simulation. They deal with the way that the nuclear weapon will act under certain conditions based on physics. They also study nuclear properties, vibrations, high explosives, advanced hydrodynamics, material strength and damage, thermal and fluid response, and radiation and electrical responses.
Nuclear force
A quantitative description of the nuclear force relies on equations that are partly empirical. These equations model the internucleon potential energies, or potentials. (Generally, forces within a system of particles can be more simply modeled by describing the system's potential energy; the negative gradient of a potential is equal to the vector force.) The constants for the equations are phenomenological, that is, determined by fitting the equations to experimental data. The internucleon potentials attempt to describe the properties of nucleon–nucleon interaction. Once determined, any given potential can be used in, e.g., the Schrödinger equation to determine the quantum mechanical properties of the nucleon system.
Atomic nucleus
Although the standard model of physics is widely believed to completely describe the composition and behavior of the nucleus, generating predictions from theory is much more difficult than for most other areas of particle physics. This is due to two reasons:Historically, experiments have been compared to relatively crude models that are necessarily imperfect. None of these models can completely explain experimental data on nuclear structure.
Nuclear fission
By contrast, most chemical oxidation reactions (such as burning coal or TNT) release at most a few eV per event. So, nuclear fuel contains at least ten million times more usable energy per unit mass than does chemical fuel. The energy of nuclear fission is released as kinetic energy of the fission products and fragments, and as electromagnetic radiation in the form of gamma rays; in a nuclear reactor, the energy is converted to heat as the particles and gamma rays collide with the atoms that make up the reactor and its working fluid, usually water or occasionally heavy water or molten salts.
When a uranium nucleus fissions into two daughter nuclei fragments, about 0.1 percent of the mass of the uranium nucleus appears as the fission energy of ~200 MeV. For uranium-235 (total mean fission energy 202.79 MeV), typically ~169 MeV appears as the kinetic energy of the daughter nuclei, which fly apart at about 3% of the speed of light, due to Coulomb repulsion. Also, an average of 2.5 neutrons are emitted, with a mean kinetic energy per neutron of ~2 MeV (total of 4.8 MeV). The fission reaction also releases ~7 MeV in prompt gamma ray photons. The latter figure means that a nuclear fission explosion or criticality accident emits about 3.5% of its energy as gamma rays, less than 2.5% of its energy as fast neutrons (total of both types of radiation ~ 6%), and the rest as kinetic energy of fission fragments (this appears almost immediately when the fragments impact surrounding matter, as simple heat). In an atomic bomb, this heat may serve to raise the temperature of the bomb core to 100 million kelvin and cause secondary emission of soft X-rays, which convert some of this energy to ionizing radiation. However, in nuclear reactors, the fission fragment kinetic energy remains as low-temperature heat, which itself causes little or no ionization.
Masao Horiba
Originally interested in mathematics and astronomy, Horiba was introduced to nuclear physics by one of his high school teachers at the Konan Boys' High School. He received a B.S. in physics, and hoped to study nuclear physics with Bunsaku Arakatsu at Kyoto University. However, further study in nuclear physics was not possible in post-war Japan. The American authorities had banned such study, and instruments and testing devices had been removed or destroyed.
Hypernucleus
The strangeness quantum number is conserved by the strong and electromagnetic interactions, a variety of reactions give access to depositing one or more units of strangeness in a nucleus. Hypernuclei containing the lightest hyperon, the Lambda, live long enough to have sharp nuclear energy levels. Therefore, they offer opportunities for nuclear spectroscopy, as well as reaction mechanism study and other types of nuclear physics (hypernuclear physics).
Nuclear binding energy
Nuclear binding energy is explained by the basic principles involved in nuclear physics.
Nuclear data
Nuclear data represents measured (or evaluated) probabilities of various physical interactions involving the nuclei of atoms. It is used to understand the nature of such interactions by providing the fundamental input to many models and simulations, such as fission and fusion reactor calculations, shielding and radiation protection calculations, criticality safety, nuclear weapons, nuclear physics research, medical radiotherapy, radioisotope therapy and diagnostics, particle accelerator design and operations, geological and environmental work, radioactive waste disposal calculations, and space travel calculations
L. Ron Hubbard
Scientology accounts say that he "studied nuclear physics at George Washington University in Washington, D.C., before he started his studies about the mind, spirit and life" and Hubbard himself stated that he "set out to find out from nuclear physics a knowledge of the physical universe, something entirely lacking in Asian philosophy". His university records indicate that his exposure to "nuclear physics" consisted of one class in "atomic and molecular phenomena" for which he earned an "F" grade.
Nuclear physics
Particle physics evolved out of nuclear physics and the two fields are typically taught in close association. Nuclear astrophysics, the application of nuclear physics to astrophysics, is crucial in explaining the inner workings of stars and the origin of the chemical elements.
Neutron
The neutron is essential to the production of nuclear power. In the decade after the neutron was discovered by James Chadwick in 1932, neutrons were used to induce many different types of nuclear transmutations. With the discovery of nuclear fission in 1938, it was quickly realized that, if a fission event produced neutrons, each of these neutrons might cause further fission events, etc., in a cascade known as a nuclear chain reaction. These events and findings led to the first self-sustaining nuclear reactor (Chicago Pile-1, 1942) and the first nuclear weapon (Trinity, 1945).
Physics
With the standard consensus that the laws of physics are universal and do not change with time, physics can be used to study things that would ordinarily be mired in uncertainty. For example, in the study of the origin of the earth, one can reasonably model earth's mass, temperature, and rate of rotation, as a function of time allowing one to extrapolate forward or backward in time and so predict future or prior events. It also allows for simulations in engineering which drastically speed up the development of a new technology.
Nuclear power in India
On 23 March 1948, Prime Minister Jawaharlal Nehru introduced the Atomic Energy Bill in the Indian Parliament, and it was subsequently passed as the Indian Atomic Energy Act. Modelled on the British Atomic Energy Act 1946, the Act granted sweeping powers to the central government over nuclear science and research, including surveying for atomic minerals, the development of such mineral resources on an industrial scale, conducting research regarding the scientific and technical problems connected with developing atomic energy for peaceful purposes, the training and education of the necessary personnel and the fostering of fundamental research in the nuclear sciences in Indian laboratories, institutes and universities. Around the same time, the Government of West Bengal sanctioned the construction of a nuclear physics institute under the University of Calcutta; the cornerstone was laid in May 1948, and the institute was inaugurated on 11 January 1950 by Irène Joliot-Curie.
Nuclear force
In 1934, Hideki Yukawa made the earliest attempt to explain the nature of the nuclear force. According to his theory, massive bosons (mesons) mediate the interaction between two nucleons. Although, in light of quantum chromodynamics (QCD), meson theory is no longer perceived as fundamental, the meson-exchange concept (where hadrons are treated as elementary particles) continues to represent the best working model for a quantitative "NN" potential. The Yukawa potential (also called a screened Coulomb potential) is a potential of the form
Effects of nuclear explosions
In 1942 there was some initial speculation among the scientists developing the first nuclear weapons that there might be a possibility of igniting the Earth's atmosphere with a large enough nuclear explosion. This would concern a nuclear reaction of two nitrogen atoms forming a carbon and an oxygen atom, with release of energy. This energy would heat up the remaining nitrogen enough to keep the reaction going until all nitrogen atoms were consumed. Hans Bethe was assigned the task of studying whether there was a possibility in the very early days, and concluded there was no possibility due to inverse Compton effect cooling of the fireball. Richard Hamming, a mathematician, was asked to make a similar calculation just before Trinity, with the same result. Nevertheless, the notion has persisted as a rumor for many years, and was the source of gallows humor at the Trinity test.
Nuclear fission
News spread quickly of the new discovery, which was correctly seen as an entirely novel physical effect with great scientific—and potentially practical—possibilities. Meitner's and Frisch's interpretation of the discovery of Hahn and Strassmann crossed the Atlantic Ocean with Niels Bohr, who was to lecture at Princeton University. I.I. Rabi and Willis Lamb, two Columbia University physicists working at Princeton, heard the news and carried it back to Columbia. Rabi said he told Enrico Fermi; Fermi gave credit to Lamb. Bohr soon thereafter went from Princeton to Columbia to see Fermi. Not finding Fermi in his office, Bohr went down to the cyclotron area and found Herbert L. Anderson. Bohr grabbed him by the shoulder and said: “Young man, let me explain to you about something new and exciting in physics.” It was clear to a number of scientists at Columbia that they should try to detect the energy released in the nuclear fission of uranium from neutron bombardment. On 25 January 1939, a Columbia University team conducted the first nuclear fission experiment in the United States, which was done in the basement of Pupin Hall; the members of the team were Herbert L. Anderson, Eugene T. Booth, John R. Dunning, Enrico Fermi, G. Norris Glasoe, and Francis G. Slack. The experiment involved placing uranium oxide inside of an ionization chamber and irradiating it with neutrons, and measuring the energy thus released. The results confirmed that fission was occurring and hinted strongly that it was the isotope uranium 235 in particular that was fissioning. The next day, the Fifth Washington Conference on Theoretical Physics began in Washington, D.C. under the joint auspices of the George Washington University and the Carnegie Institution of Washington. There, the news on nuclear fission was spread even further, which fostered many more experimental demonstrations.
Nuclear force
The nuclear force (or nucleon–nucleon interaction or residual strong force) is a force that acts between the protons and neutrons of atoms. Neutrons and protons, both nucleons, are affected by the nuclear force almost identically. Since protons have charge +1 "e", they experience an electric force that tends to push them apart, but at short range the attractive nuclear force is strong enough to overcome the electromagnetic force. The nuclear force binds nucleons into atomic nuclei.
Fundamental Fysiks Group
Hugh Gusterson writes that several challenging ideas lie at the heart of quantum physics: that electrons behave like waves and particles; that you can know a particle's location or momentum, but not both; that observing a particle changes its behavior; and that particles appear to communicate with each other across great distances, known as nonlocality and quantum entanglement. It is these concepts that led to the development of quantum information science and quantum encryption, which has been experimentally used, for example, to transfer money and electronic votes. Kaiser argues that the Fundamental Fysiks Group saved physics by exploring these ideas, in three ways:
History of nuclear weapons
Nuclear weapons possess enormous destructive power from nuclear fission or combined fission and fusion reactions. Building on scientific breakthroughs made during the 1930s, the United States, the United Kingdom and Canada collaborated during World War II, in what was called the Manhattan Project, to counter the suspected Nazi German atomic bomb project. In August 1945, two fission bombs were dropped on Japan, standing to date as the only use of nuclear weapons in combat. The Soviet Union started development shortly thereafter with their own atomic bomb project, and not long after that both countries developed even more powerful fusion weapons known as "hydrogen bombs".
Force
There are two "nuclear forces", which today are usually described as interactions that take place in quantum theories of particle physics. The strong nuclear force is the force responsible for the structural integrity of atomic nuclei while the weak nuclear force is responsible for the decay of certain nucleons into leptons and other types of hadrons.
Nuclear Power and the Environment
Chapter Four emphasizes on major issues raised by nuclear power. The reason why chapter two and chapter three are so detailed in the effects of radioactivity and the principles of nuclear power along with the nuclear fuel cycle is so that there could be a better understanding on the problems that could cause environmental effects. Concerns about nuclear development, which is considered in detail in other chapters, centers on a few major issues. This chapter focuses on issues as a whole to ensure that they can be seen in the perspective that allows people to understand the underlying social and ethical questions that they raise. It begins with the world energy demand, the problem scale of nuclear development, and nuclear hazards that stem from other technological developments. The advantages must be weighed against the fears and risks attached to nuclear power, which can lead to many people disregarding nuclear power as an acceptable means of energy, also referred to as "the Faustian bargain." Certainly these fears must be taken seriously and can not be disregarded. This chapter concludes with the concerns of the future and the fact that the world is on the threshold of a huge commitment to fission power, which if fully entered into, it may be effectively impossible to reverse for a century or more.
Nuclear structure
In the case of the Hartree–Fock approaches, the trouble is not to find the mathematical function which describes best the nuclear potential, but that which describes best the nucleon–nucleon interaction. Indeed, in contrast with atomic physics where the interaction is known (it is the Coulomb interaction), the nucleon–nucleon interaction within the nucleus is not known analytically.
Nuclear physics
Alexandru Proca was the first to develop and report the massive vector boson field equations and a theory of the mesonic field of nuclear forces. Proca's equations were known to Wolfgang Pauli who mentioned the equations in his Nobel address, and they were also known to Yukawa, Wentzel, Taketani, Sakata, Kemmer, Heitler, and Fröhlich who appreciated the content of Proca's equations for developing a theory of the atomic nuclei in Nuclear Physics.
Japanese nuclear weapon program
In 1934, Tohoku University professor Hikosaka Tadayoshi's "atomic physics theory" was released. Hikosaka pointed out the huge energy contained by nuclei and the possibility that both nuclear power generation and weapons could be created.
In December 1938, the German chemists Otto Hahn and Fritz Strassmann sent a manuscript to "Naturwissenschaften" reporting that they had detected the element barium after bombarding uranium with neutrons; simultaneously, they communicated these results to Lise Meitner. Meitner, and her nephew Otto Robert Frisch, correctly interpreted these results as being nuclear fission and Frisch confirmed this experimentally on 13 January 1939. Physicists around the world immediately realized that chain reactions could be produced and notified their governments of the possibility of developing nuclear weapons.
Branches of physics
Physics deals with the combination of matter and energy. It also deals with a wide variety of systems, about which theories have been developed that are used by physicists. In general, theories are experimentally tested numerous times before they are accepted as correct as a description of Nature (within a certain domain of validity). For instance, the theory of classical mechanics accurately describes the motion of objects, provided they are much larger than atoms and moving at much less than the speed of light. These theories continue to be areas of active research: for instance, a remarkable aspect of classical mechanics known as chaos was discovered in the 20th century, three centuries after the original formulation of classical mechanics by Isaac Newton (1642–1727). These "central theories" are important tools for research in more specialized topics, and any physicist, regardless of his or her specialization, is expected to be literate in them.
Nucleon
Nucleons sit at the boundary where particle physics and nuclear physics overlap. Particle physics, particularly quantum chromodynamics, provides the fundamental equations that explain the properties of quarks and of the strong interaction. These equations explain quantitatively how quarks can bind together into protons and neutrons (and all the other hadrons). However, when multiple nucleons are assembled into an atomic nucleus (nuclide), these fundamental equations become too difficult to solve directly (see lattice QCD). Instead, nuclides are studied within nuclear physics, which studies nu and their interactions by approximations and models, such as the nuclear shell model. These models can successfully exp nuclide properties, as for example, whether or not a particular nuclide undergoes radioactive decay.
Atomic and molecular astrophysics
Atomic astrophysics is concerned with performing atomic physics calculations that will be useful to astronomers and using atomic data to interpret astronomical observations. Atomic physics plays a key role in astrophysics as astronomers' only information about a particular object comes through the light that it emits, and this light arises through atomic transitions.
Anti-nuclear movement
In his book "Global Fission: The Battle Over Nuclear Power", Jim Falk explores connections between technological concerns and political concerns. Falk suggests that concerns of citizen groups or individuals who oppose nuclear power have often focused initially on the "range of physical hazards which accompany the technology" and leads to a "concern over the political relations of the nuclear industry" A more neutral observer might observe that this is nothing more than a conspiracy theory. Baruch Fischhoff, a social science professor said that many people really do not trust the nuclear industry. Wade Allison, a physics professor actually says "radiation is safe & all nations should embrace nuclear technology"
Nuclear physics
With the discovery of the neutron, scientists could at last calculate what fraction of binding energy each nucleus had, by comparing the nuclear mass with that of the protons and neutrons which composed it. Differences between nuclear masses were calculated in this way. When nuclear reactions were measured, these were found to agree with Einstein's calculation of the equivalence of mass and energy to within 1% as of 1934.
Even and odd atomic nuclei
In nuclear physics, properties of a nucleus depend on evenness or oddness of its atomic number "Z", neutron number "N" and, consequently, of their sum, the mass number "A". Most notably, oddness of both "Z" and "N" tends to lower the nuclear binding energy, making odd nuclei, generally, less stable. This effect is not only experimentally observed, but is included to the semi-empirical mass formula and explained by some other nuclear models, such as nuclear shell model. This remarkable difference of nuclear binding energy between neighbouring nuclei, especially of odd-"A" isobars, has important consequences for beta decay.
Joint Institute for Nuclear Research
The Institute has seven laboratories, each with its own specialisation: theoretical physics, high energy physics (particle physics), heavy ion physics, condensed matter physics, nuclear reactions, neutron physics, and information technology. The institute has a division to study radiation and radiobiological research and other ad hoc experimental physics experiments.
Mass–energy equivalence
The mass–energy equivalence formula was used in the understanding of nuclear fission reactions, and implies the great amount of energy that can be released by a nuclear fission chain reaction, used in both nuclear weapons and nuclear power. By measuring the mass of different atomic nuclei and subtracting from that number the total mass of the protons and neutrons as they would weigh separately, one gets the exact binding energy available in an atomic nucleus. This is used to calculate the energy released in any nuclear reaction, as the difference in the total mass of the nuclei that enter and exit the reaction.
Nuclear astrophysics
After Aston demonstrated that the mass of helium is less than four times that of the proton, Eddington proposed that, through an unknown process in the Sun's core, hydrogen is transmuted into helium, liberating energy. Twenty years later, Bethe and von Weizsäcker independently derived the CN cycle, the first known nuclear reaction that accomplishes this transmutation. However, the Sun's primary energy source is now understood to be proton–proton chain reactions, occurring at much lower energies and much more slowly than catalytic hydrogen fusion. The interval between Eddington's proposal and derivation of the CN cycle can mainly be attributed to an incomplete understanding of nuclear structure. A proper understanding of nucleosynthetic processes only came when Chadwick discovered the neutron in 1932 and beta decay theory developed. Nuclear physics gives a picture of the Sun's energy source producing a lifetime consistent with the age of the Solar System derived from meteoritic abundances of lead and uranium isotopes — about 4.5 billion years. The mass of stars like the Sun allow core hydrogen burning on the main sequence of the Hertzsprung-Russell diagram via pp-chains for about 9 billion years. This primarily is determined by extremely slow production of deuterium,
Nuclear data
There are two major reasons to need high-quality nuclear data: theoretical model development of nuclear physics, and applications involving radiation and nuclear power. There is often an interplay between these two aspects, since applications often motivate research in particular theoretical fields, and theory can be used to predict quantities or phenomena which can lead to new or improved technological concepts.
Science and engineering in Manchester
In the late 19th and early 20th century, Manchester gained a pioneering reputation for a city at the centre of physics, namely in the field of nuclear physics. The 'Nuclear Family' was the alias given to a group of scientists who studied nuclear physics in Manchester. 'Family' highlights the consistent development through the generations in nuclear physics, beginning with Thomson in the late 18th century and ending with James Chadwick in the 1930s who discovered the neutron. Ernest Rutherford is often described as the 'father of nuclear physics', equally the same could be said of J. J. Thomson who discovered the electron and isotopes, and ultimately taught Rutherford who later go on to split the atom. Scientists who were part of the 'nuclear family' in Manchester included J. J. Thomson, Ernest Rutherford, Niels Bohr, Hans Geiger, Ernest Marsden, John Cockcroft and James Chadwick.
University of Cambridge
In physics, Ernest Rutherford who is regarded as the father of nuclear physics, spent much of his life at the university where he worked closely with E. J. Williams and Niels Bohr, a major contributor to the understanding of the atom, J. J. Thomson, discoverer of the electron, Sir James Chadwick, discoverer of the neutron, and Sir John Cockcroft and Ernest Walton, responsible for first splitting the atom. J. Robert Oppenheimer, leader of the Manhattan Project that developed the atomic bomb, also studied under Rutherford and Thomson. Joan Curran devised the 'chaff' technique during the Second World War to disrupt radar on enemy planes.
Astronomers Sir John Herschel, Sir Arthur Eddington, Paul Dirac, the discoverer of antimatter and one of the pioneers of quantum mechanics; Stephen Hawking, theoretical physicist and the university's long-serving Lucasian Professor of Mathematics until 2009; and Lord Martin Rees, the current Astronomer Royal and former Master of Trinity College. John Polkinghorne, a mathematician before his entrance into the Anglican ministry, received the Templeton Prize for his work reconciling science and religion.
Nuclear Industry Association
Subjects covered include the pros and cons of different sources of energy, how nuclear power works, the types of jobs available in the nuclear sector through the apprenticeship and graduate route, as well as practical sessions on natural radiation and half life.
History of subatomic physics
The most developed branch of nuclear physics in 1940s was studies related to nuclear fission due to its military significance. The main focus of fission-related problems is interaction of atomic nuclei with neutrons: a process that occurs in a fission bomb and a nuclear fission reactor. It gradually drifted away from the rest of subatomic physics and virtually became the nuclear engineering. First synthesised transuranium elements were also obtained in this context, through neutron capture and subsequent β decay.
Nuclear fission
The variation in specific binding energy with atomic number is due to the interplay of the two fundamental forces acting on the component nucleons (protons and neutrons) that make up the nucleus. Nuclei are bound by an attractive nuclear force between nucleons, which overcomes the electrostatic repulsion between protons. However, the nuclear force acts only over relatively short ranges (a few nucleon diameters), since it follows an exponentially decaying Yukawa potential which makes it insignificant at longer distances. The electrostatic repulsion is of longer range, since it decays by an inverse-square rule, so that nuclei larger than about 12 nucleons in diameter reach a point that the total electrostatic repulsion overcomes the nuclear force and causes them to be spontaneously unstable. For the same reason, larger nuclei (more than about eight nucleons in diameter) are less tightly bound per unit mass than are smaller nuclei; breaking a large nucleus into two or more intermediate-sized nuclei releases energy.
Deutsche Physik
It is occasionally put forth that there is a great irony in the Nazis' labeling modern physics as "Jewish science", since it was exactly modern physics—and the work of many European exiles—which was used to create the atomic bomb. Even if the German government had not embraced Lenard and Stark's ideas, the German antisemitic agenda was enough by itself to destroy the Jewish scientific community in Germany. Furthermore, the German nuclear energy project was never pursued with anywhere near the vigor of the Manhattan Project in the United States, and for that reason would likely not have succeeded in any case. The movement did not actually go as far as preventing the nuclear energy scientists from using quantum mechanics and relativity, but the education of young scientists and engineers suffered, not only from the loss of the Jewish scientists but also from political appointments and other interference. In 1938, Himmler wrote to Heisenberg that he could discuss modern physics but not mention Jewish scientists such as Bohr and Einstein in connection with it.
School of Physics and Technology of University of Kharkiv
The specialty "Medical Physics" (with specializations in "Medical Radiation Physics" and "Medical Biophysics") has existed at the school since 2005. Students studying nuclear physics and medical physics study in different groups and attend different courses: nuclear physicists specialize in experimental nuclear physics, while medical physics students study biology and medical equipment in more detail.
Nuclear reactor physics
Nuclear reactor physics is the branch of science that deals with the study and application of chain reaction to induce a controlled rate of fission in a nuclear reactor for the production of energy.
Most nuclear reactors use a chain reaction to induce a controlled rate of nuclear fission in fissile material, releasing both energy and free neutrons. A reactor consists of an assembly of nuclear fuel (a reactor core), usually surrounded by a neutron moderator such as regular water, heavy water, graphite, or zirconium hydride, and fitted with mechanisms such as control rods that control the rate of the reaction.
Astronomy
Various fields of physics are crucial to studying the universe. Interdisciplinary studies involve the fields of quantum mechanics, particle physics, plasma physics, condensed matter physics, statistical mechanics, optics, and nuclear physics.
Noor Muhammad Butt
During his studies, Butt learned the course on the Kinetic theory of solids from Prof. Rudolf Peierls, a leading member and senior scientist who participated in the Manhattan Project and who was still working as the Head of the implosion device being developed under this project in the early 1940s. Thus, at Birmingham University during his studies for PhD, Butt had studied and taught nuclear physics under three world known nuclear professors whose names form part of the nuclear history of the world. Later, Butt had a rich and full interaction with a large number of nuclear and material scientists of over 25 countries during his lectures and seminars at the laboratories of these countries of the East and the West.
Strong interaction
In particle physics, the strong interaction is the mechanism responsible for the strong nuclear force (also called the strong force, nuclear strong force, or colour force), and is one of the four known fundamental interactions, with the others being electromagnetism, the weak interaction, and gravitation. At the range of 10 m (1 femtometer), the strong force is approximately 137 times as strong as electromagnetism, a million times as strong as the weak interaction, and 10 times as strong as gravitation. The strong nuclear force holds most ordinary matter together because it confines quarks into hadron particles such as the proton and neutron. In addition, the strong force binds neutrons and protons to create atomic nuclei. Most of the mass of a common proton or neutron is the result of the strong force field energy; the individual quarks provide only about 1% of the mass of a proton.
History of subatomic physics
The elements beyond fermium cannot be produced in this way. To make a nuclide with more than 100 protons per nucleus one has to use an inventory and methods of particle physics (see details below), namely to accelerate and collide atomic nuclei. Production of progressively heavier synthetic elements continued into 21st century as a branch of nuclear physics, but only for scientific purposes.
Nuclear fusion
The release of energy with the fusion of light elements is due to the interplay of two opposing forces: the nuclear force, which combines together protons and neutrons, and the Coulomb force, which causes protons to repel each other. Protons are positively charged and repel each other by the Coulomb force, but they can nonetheless stick together, demonstrating the existence of another, short-range, force referred to as nuclear attraction. Light nuclei (or nuclei smaller than iron and nickel) are sufficiently small and proton-poor allowing the nuclear force to overcome repulsion. This is because the nucleus is sufficiently small that all nucleons feel the short-range attractive force at least as strongly as they feel the infinite-range Coulomb repulsion. Building up nuclei from lighter nuclei by fusion releases the extra energy from the net attraction of particles. For larger nuclei, however, no energy is released, since the nuclear force is short-range and cannot continue to act across longer atomic length scales. Thus, energy is not released with the fusion of such nuclei; instead, energy is required as input for such processes.
Physics
Contemporary research in physics can be broadly divided into nuclear and particle physics; condensed matter physics; atomic, molecular, and optical physics; astrophysics; and applied physics. Some physics departments also support physics education research and physics outreach.
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or from a combination of fission and fusion reactions (thermonuclear bomb). Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to . The first thermonuclear ("hydrogen") bomb test released energy approximately equal to . A thermonuclear weapon weighing little more than can release energy equal to more than . A nuclear device no larger than traditional bombs can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy.
Nuclear fission
The charge of a uranium nucleus, we found, was indeed large enough to overcome the effect of the surface tension almost completely; so the uranium nucleus might indeed resemble a very wobbly unstable drop, ready to divide itself at the slightest provocation, such as the impact of a single neutron. But there was another problem. After separation, the two drops would be driven apart by their mutual electric repulsion and would acquire high speed and hence a very large energy, about 200 MeV in all; where could that energy come from? ...Lise Meitner... worked out that the two nuclei formed by the division of a uranium nucleus together would be lighter than the original uranium nucleus by about one-fifth the mass of a proton. Now whenever mass disappears energy is created, according to Einstein's formula "E"= "mc", and one-fifth of a proton mass was just equivalent to 200 MeV. So here was the source for that energy; it all fitted!
In short, Meitner and Frisch had correctly interpreted Hahn's results to mean that the nucleus of uranium had split roughly in half. Frisch suggested the process be named "nuclear fission", by analogy to the process of living cell division into two cells, which was then called binary fission. Just as the term nuclear "chain reaction" would later be borrowed from chemistry, so the term "fission" was borrowed from biology.
Nuclear binding energy
The best-known classes of exothermic nuclear transmutations are fission and fusion. Nuclear energy may be liberated by atomic fission, when heavy atomic nuclei (like uranium and plutonium) are broken apart into lighter nuclei. The energy from fission is used to generate electric power in hundreds of locations worldwide. Nuclear energy is also released during atomic fusion, when light nuclei like hydrogen are combined to form heavier nuclei such as helium. The Sun and other stars use nuclear fusion to generate thermal energy which is later radiated from the surface, a type of stellar nucleosynthesis. In any exothermic nuclear process, nuclear mass might ultimately be converted to thermal energy, given off as heat.
Nuclear power in India
By 1939, Meghnad Saha, the Palit Professor of Physics at the University of Calcutta, had recognised the significance of the discovery of nuclear fission, and had begun to conduct various experiments in his laboratory related to nuclear physics. In 1940, he incorporated nuclear physics into the university's post-graduate curriculum. In the same year, the Sir Dorabji Tata Trust sanctioned funds for installing a cyclotron at the University of Calcutta, but various difficulties likely related to the war delayed the project. In 1944, Homi J. Bhabha, a distinguished nuclear physicist who had established a research school at the Indian Institute of Science, Bangalore, wrote a letter to his distant cousin J. R. D. Tata, the chairman of the Tata Group. He requested funds to establish a research institute of fundamental physics, "with special reference to cosmic rays and nuclear physics." The Tata Institute of Fundamental Research (TIFR) was inaugurated in Mumbai the following year.
The Universe Around Us
"In the interval since the third edition appeared, astronomy has continued its triumphal progress. Perhaps the most noteworthy single episode has been the discovery that the physics of atomic nuclei can not only give a satisfactory account of the radiation of the sun and stars, but can also explain many hitherto puzzling stellar characteristics; the largest and smallest ingredients of nature - the star and the atomic nucleus - have met and thrown light on one another, to the great improvement of our understanding of both. This and other outstanding advances have necessitated many changes in and additions to my book. A large part of it has been rewritten, while most of the remainder has been substantially amended."-J.H.JEANS - DORKING, September 1943
Nuclear force
The nuclear force also has a tensor component which depends on the interaction between the nucleon spins and the angular momentum of the nucleons, leading to deformation from a simple spherical shape.
Nuclear power debate
Proponents of nuclear energy argue that nuclear power is a clean and sustainable energy source which provides huge amounts of uninterrupted energy without polluting the atmosphere or emitting the carbon emissions that cause global warming. Use of nuclear power provides plentiful, well-paying jobs, energy security, reduces a dependence on imported fuels and exposure to price risks associated with resource speculation and Middle East politics. Proponents advance the notion that nuclear power produces virtually no air pollution, in contrast to the massive amount of pollution and carbon emission generated from burning fossil fuels like coal, oil and natural gas. Modern society demands always-on energy to power communications, computer networks, transportation, industry and residences at all times of day and night. In the absence of nuclear power, utilities need to burn fossil fuels to keep the energy grid reliable, even with access to solar and wind energy, because those sources are intermittent. Proponents also believe that nuclear power is the only viable course for a country to achieve energy independence while also meeting their "ambitious" nationally determined contributions (NDC's) to reduce carbon emissions in accordance with the Paris Agreement signed by 195 nations. They emphasize that the risks of storing waste are small and existing stockpiles can be reduced by using this waste to produce fuels for the latest technology in newer reactors. The operational safety record of nuclear is excellent when compared to the other major kinds of power plants and by preventing pollution, actually saves lives every year.
Comparison of chemistry and physics
In a typical undergraduate program for physics majors, required courses are in the sub-disciplines of physics, with additional required courses in mathematics. Because much of the insight of physics is described by differential equations relating matter, space, and time (for example Newton's law of motion and the Maxwell equations of electromagnetism), students have to be familiar with differential equations. In a typical undergraduate program for chemistry majors, emphasis is placed on laboratory classes and understanding and applying models describing chemical bonds and molecular structure. Emphasis is also placed in the methods for analysis and the formulas and equations used when considering the chemical transformation. Students take courses in math, physics, chemistry, and often biochemistry. Between the two programs of study, there is a large area of overlap (calculus, introductory physics, quantum mechanics, thermodynamics). However, physics places a larger emphasis on fundamental theory (with its deep mathematical treatment) while chemistry places more emphasis in combining the most important mathematical definitions of the theory with the approach of the molecular models. Laboratory skills may differ in both programs, as students may be involved in different technologies, depending on the program and the institution of higher education (for example, a chemistry student may spend more laboratory time dealing with glassware for distillation and purification or on a form of chromatography-spectroscopy instrument, while a physics student may spend much more time dealing with a laser and non-linear optics technology or some complex electrical circuit).
Noor Muhammad Butt
The same year, he was accepted at the Government College, Lahore to do his master's degree in physics. In 1957, he completed his Master of Science (MSc) with experimental specialisation in nuclear physics under nuclear physicist Professor Rafi Muhammad Chaudhry, the Head of the Department of Physics at the Government College University at that time. It was under Chaudhry's supervision that Butt studied nuclear physics and supervised Butts' master's degree's thesis in experimental nuclear physics using the 1.2 MeV Cockcrof-Walton Nuclear Accelerator installed at the College. His master's degree's thesis was written on ""The nuclear reactions when the protons from this accelerator strike the nuclear target of lithium produce a nuclear reaction, breaking the atomic nucleus of lithium"". After his master's degree, Butt joined Government College University as a lecturer in physics. He stayed there till 1960. In 1961, he won a Commonwealth Scholarship and the Pakistan Atomic Energy Commission Scholarship to pursue his doctoral studies in Europe. On his mentors' advice, Butt travelled to the United Kingdom where he attended the University of Birmingham.
Nuclear family
The concept that narrowly defines a nuclear family is central to stability in modern society that has been promoted by familialists who are social conservatives in the United States, and has been challenged as historically and sociologically inadequate to describe the complexity of actual family relations. In "Freudian Theories of Identification and Their Derivatives" Urie Bronfenbrenner states, "Very little is known about the extent variation in the behavior of fathers and mothers towards sons and daughters, and even less about the possible effects on such differential treatment." Little is known about how parental behavior and identification processes work, and how children interpret sex role learning. In his theory he uses "identification" with the father in the sense that the son will follow the sex role provided by his father and then for the father to be able identify the difference of the "cross sex" parent for his daughter.
Subatomic particle
Chemistry concerns itself with how electron sharing binds atoms into structures such as crystals and molecules. Nuclear physics deals with how protons and neutrons arrange themselves in nuclei. The study of subatomic particles, atoms and molecules, and their structure and interactions, requires quantum mechanics. Analyzing processes that change the numbers and types of particles requires quantum field theory. The study of subatomic particles "per se" is called particle physics. The term "high-energy physics" is nearly synonymous to "particle physics" since creation of particles requires high energies: it occurs only as a result of cosmic rays, or in particle accelerators. Particle phenomenology systematizes the knowledge about subatomic particles obtained from these experiments.
Atomic nucleus
The branch of physics concerned with the study and understanding of the atomic nucleus, including its composition and the forces which bind it together, is called nuclear physics.
A Is for Atom
The history of atomic energy is then over viewed beginning with the discovery of artificial transmutation. This then led to the discovery of nuclear fission and eventually nuclear weapons and nuclear energy using the chain reaction of radioactive material. The Oakridge uranium factory is then discussed as well as the first nuclear reactor and the first uses of plutonium. The future of fantastical nuclear power plants is then explained. The short ends on the uses of radio isotopes in medicine and agriculture.
Nuclear physics
Much of current research in nuclear physics relates to the study of nuclei under extreme conditions such as high spin and excitation energy. Nuclei may also have extreme shapes (similar to that of Rugby balls or even pears) or extreme neutron-to-proton ratios. Experimenters can create such nuclei using artificially induced fusion or nucleon transfer reactions, employing ion beams from an accelerator. Beams with even higher energies can be used to create nuclei at very high temperatures, and there are signs that these experiments have produced a phase transition from normal nuclear matter to a new state, the quark–gluon plasma, in which the quarks mingle with one another, rather than being segregated in triplets as they are in neutrons and protons.
Nuclear power debate
Two opposing camps have evolved in society with respect to nuclear power, one supporting and promoting nuclear power and another opposing it. At the heart of this divide sit different views of risk and individual beliefs regarding public involvement in making decisions about large-scale high technology. Questions which emerge include: is nuclear power safe for humans and the environment? Could another Chernobyl disaster or Fukushima disaster happen? Can we dispose of nuclear waste in a safe manner? Can nuclear power help to reduce climate change and air pollution in a timely way?