Measurement of Proton’s Energy Loss Through Thin Gold Film

The National Institute of Standards and Technology (NIST) aims to reduce the systematic uncertainties of the energy spectrum in the neutron's lifetime experiment, but the presence of any "dead" layer inside the detector affects the energy spectrum of low-energy ions. In order to take this factor into account, we conducted this experiment to determine energy loss spectra of proton beam within the "Gold" dead layer, and compare this spectra with the Stopping Power (SP) of Gold from the NIST's database. To that end, we generated 50-200 keV energy proton beam in Gettysburg College's 200 keV Van de Graff proton accelerator and collected the proton counts received by the Si detector, containing Gold dead layer, for different corresponding energy channels using energy spectra measuring software. As a result, we had to evaporate gold onto different batches of circular glass slides, and Si detector within the Gold Evaporator chamber and determined the thickness of gold layers by utilizing UV-Vis Spectroscopy technology, and AFM Technology. Employing these data, we plotted SP of the Gold dead layer versus the kinetic energy of the proton beam using the thickness function of the Gold, and differentiated this plot with the graph of SP of Gold collected from the NIST database.