since any new data will be saved to a file named <HPGE.rpt> overwriting the previous data. Nomenclature  You will be observing rays from the decay of cobalt-60, cesium-137, sodium-22, and, maybe barium-133. The number following the element is the atomic number A: the number of protons Z plus the number of neutrons N in the nucleus. So, A = N + Z. The name of the element tells you the number of protons Z in the nucleus: 29 for cobalt, 55 for cesium, 11 for sodium, and 56 for barium. So, the difference between these two numbers gives the number of neutrons N = A Z. Element with the same number of protons Z (and, therefore, the same name) but different numbers of neutrons N are called isotopes. Unstable isotopes decay and are called radioisotopes. So, for example, the common stable isotope of sodium found in common compounds is sodium-23. Data sheets on each of these nuclei are available for your reference as are sheets outlining the decay schemes. Review these and record the relevant decay equation for each element in your notebook. The nuclei are expressed as . So sodium-23 is and so on. Obtaining Nuclear Spectra and Calibrating the MCA The high voltage supply should be on and set at 3000 V. The MCA software should be on and ready to go. Your cobalt-60 sample should be in place. Press "Acquire" in the "MCA" window to start acquiring a spectrum. While data is being collected, you can change the vertical range in the window by using the scroll bar. It's like the vertical control on an oscilloscope: it affects the display only. The way in which the actual data is being collected is unaffected. Use the "Expand On" button to look at one of the two peaks in cobalt-60. You can watch it grow as you collect data. The cobalt-60 source has the highest gamma ray energies of those emitted by the sources available to us. They are the two high-energy peaks at 1.173 and 1.332 MeV as indicated in a single large-print sheet in the folder. MeV means million electron volts. These two 's. peaks are called "photo peaks" because of their correspondence to single The
since any new data will be saved to a file named <HPGE.rpt> overwriting the previous data. Nomenclature You will be observing  rays from the decay of cobalt-60, cesium-137, sodium-22, and, maybe barium-133. The number following the element is the atomic number A: the number of protons Z plus the number of neutrons N in the nucleus. So, A = N + Z. The name of the element tells you the number of protons Z in the nucleus: 29 for cobalt, 55 for cesium, 11 for sodium, and 56 for barium. So, the difference between these two numbers gives the number of neutrons N = A Z. Element with the same number of protons Z (and, therefore, the same name) but different numbers of neutrons N are called isotopes. Unstable isotopes decay and are called radioisotopes. So, for example, the common stable isotope of sodium found in common compounds is sodium-23. Data sheets on each of these nuclei are available for your reference as are sheets outlining the decay schemes. Review these and record the relevant decay equation for each element in your notebook. The nuclei are expressed as . So sodium-23 is and so on. Obtaining Nuclear Spectra and Calibrating the MCA The high voltage supply should be on and set at 3000 V. The MCA software should be on and ready to go. Your cobalt-60 sample should be in place. Press "Acquire" in the "MCA" window to start acquiring a spectrum. While data is being collected, you can change the vertical range in the window by using the scroll bar. It's like the vertical control on an oscilloscope: it affects the display only. The way in which the actual data is being collected is unaffected. Use the "Expand On" button to look at one of the two peaks in cobalt-60. You can watch it grow as you collect data. The cobalt-60 source has the highest gamma ray energies of those emitted by the sources available to us. They are the two high-energy peaks at 1.173 and 1.332 MeV as indicated in a single large-print sheet in the folder. MeV means million electron volts. These two peaks are called "photo peaks" because of their correspondence to single 's. The