Click here for the germanium gamma detector for soil and rock analysis. Your goal is to determine the radioactive isotope content of the soil and rock sample. The information for the data files are listed below. You can also obtain ascii listings of the data for your own spreadsheet by clicking on the files below.

Data acquisition was ackomplished using a Canberra Germanium detector, along with a 8196 channel software package (Genie 2000). The ascii files below contain a listing of 8196 numbers starting with the counts recorded in channel number 0 and ending with the counts recorded in channel number 8195.

Software for the java applet was written by Cal Poly Physics major Andres Cardenas. The screen displays 1024 channels at a time. Hit the pan buttons to pan left or right 512 channels. Move the left and right curser around the peak you want to analyze. Be sure to include enough of the flat background left and right of the peak. Hit "Gaussian Curvefitting", and then hit "autofit" repeatedly until the total chi-square doesn't decarease any more. Gaussian fitted photopeak data is displayed on the screen. Hit "return to normal mode" to pan the rest of the spectrum for peak analysis.

The file bk4hr.dat is a spectra obtained by counting for 4 hours with no sample present. It is the background spectra to be subracted from the other data files.

The file kcl1000.dat is a spectra obtained by counting for 1000 seconds with a pure potassium cloride sample. The mass of the KCl sample is 3117 grams, and the sample geometry is the same as for the soil sample (monro.dat).

The file pblend.dat is a spectra obtained by counting for 2 minutes with a sample of pitch-blend rock. The main isotope in the pitch-blend is U238. This spectra is to be used to identify the peaks of the U238 decay series, and to obtain an approximate relative efficiency calibration curve. It does not have the same geometry as the soil or KCl samples.

The file lantern.dat is a spectra obtained by counting for 2 minutes with a lantern mantle as a sample. The main isotope in the lantern mantle is Th232. This spectra is to be used to identify the peaks of the Th232 decay series, and to obtain an approximate relative efficiency calibration curve. It does not have the same geometry as the soil or KCl samples.

The file monro.dat is a spectra obtained by counting for 4 hours with a soil sample from the Monrova foothills. The mass of the sample is 4735 grams, and the detection geometry is the same as the KCl sample.