Physics 13 Laboratory.doc

Physics 160
Principles of Modern Physics
Laboratory session #9
Gamma Spectroscopy: Pre-Lab
Answer the following questions PRIOR ing to your lab section. You will not be allowed to participate in any data-collection until you have shown me your pre-lab and I have initialed it. Please tape or staple the pre-lab on the page opposite to the first page of your write-up; failure to do so will result in losing two points (out of a possible 20). Show all your work.
1. What is the main distinction between the Geiger-Müller tube you used in the last two labs and the scintillation detector you will use in this lab?
2. What is the natural linewidth (in MeV) of the MeV gamma ray emitted by Ba-137? Hint: You know that the half-life of Ba-137 is 153 s from last week’s lab. You will need to use the energy-time uncertainty principle.
3. Consider the interaction between a MeV gamma ray and an electron in your scintillation detector. What is the maximum energy that can be transferred to the electron (in MeV) from the gamma ray pton scattering? Hint: You will need pton equation.
Physics 160
Principles of Modern Physics
Laboratory session #9
Gamma Spectroscopy
Objectives:
To e familiar with the detection of gamma rays using a scintillation-photomultiplier tube detector and with the pulse height analysis technique for determining gamma ray energies. To understand the origi