Cal Poly Pomona Physics Department
Gamma Detector for gamma absorbtion

Click here to run the gamma detector with gamma absorbtion data . Read below for information about the data files.

Below are the data files used in the detector applet. The files are in ascii format, and are a listing of the counts recorded channel by channel. Data acquisition is done using a PCAE card from Oxford Instruments, and has 1024 channels. The ascii files below contain a listing of 1024 numbers starting with the counts recorded in channel number 0 and ending with the counts recorded in channel number 1023.

The files below can be downloaded in ascii format and read into a spreadsheet for plotting.

Data to Determine Attenuation Coefficients

This section contains gamma spectrum data with different absorbers between the source and detector. The source used was Cs137, which gives off a gamma with energy 662 KeV and an x-ray with energy of 32 KeV. For the data below, we use lead absorbers of various thickness to attenuate the 662 KeV gamma particles. All data were taken with the same source-detector geometry.

Data for 662 KeV gamma with lead absorber

The file no absorber contains spectra data for the Cs137 source with no absorber. Collection time was two minutes. The 662 KeV photopeak is at around channel 390.

The file absorber C contains spectra data for the Cs137 source with a lead absorber of thickness 2.651 g/cm2. Collection time was two minutes. The 662 KeV photopeak is at around channel 390.

The file absorber D contains spectra data for the Cs137 source with a lead absorber of thickness 4.451 g/cm2. Collection time was two minutes. The 662 KeV photopeak is at around channel 390.

The file absorber E contains spectra data for the Cs137 source with a lead absorber of thickness 7.194 g/cm2. Collection time was two minutes.

The file absorber C and E contains spectra data for the Cs137 source with a lead absorber of thickness 9.845 g/cm2. Collection time was two minutes. The 662 KeV photopeak is at around channel 390.

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