Physics307L:Winter Break Lab Fest/chargemass In this lab, you
can estimate the ratio of the charge to the mass of an electron.
However, the instrument is dying a bit, and even when it's
working, the estimate is only within a factor of 2 or so. So, we
should probably not do the careful measurements of the radius of
the circle for this lab, but rather should just explore the cool
effects of an electron beam traveling through dilute helium gas,
in the presence of a magnetic field. Some principles: -
Electrons are negatively charged - Moving, charged particles
feel a force perpendicular to their direction of motion when
traveling in a magnetic field. - Thus they travel in helical /
circular paths! - The moving electrons will cause the helium to
glow. This is similar to the glowing tubes in the Balmer series,
and also similar to fluorescent light bulbs. - Discuss safety
first! - Make sure everything is wired correctly (see manual or
student reports) - Explore how changing the accelerating
electric field and the ma