7.7 particle detectors

Question 1

What happens when a charged particle passes through a material

Answer 1

The material will become ionised

Question 2

What is the differences in ionisation between the cloud chamber and the bubble chamber

Answer 2

The cloud chamber makes use of ionisation in super saturated air while the bubble chamber makes use of ionisation in super saturated liquid hydrogen

Question 3

How can we make the path of an ionising particle visible for the cloud and bubble chamber

Answer 3

For a cloud chamber the ionised molecule along the particles path form centres for the formation of tiny liquid water drops. For the bubble chamber tiny hydrogen gas bubbles are produced. These can be illuminated and photographed to make the track of the particle visible

Question 4

What would cause the electron path in a bubble chamber to spiral and curve

Answer 4

There would be a magnetic field perpendicular to the electron’s spiral. using the left hand rule you can see that the field will be directed out of the paper.

Question 5

How can you deduce that the electron is gradually losing energy

Answer 5

The radius of the spiral is getting smaller and r = p/Be, so the radius of the electron’s path is proportional to the momentum, thus depending on kinetic energy