Electron-atom bremsstrahlung cross sections in the 20-100. keV energy region: absolute measurements for 6 = Z = 79 and comparison with theoretical databasese

摘要

We report absolute measurements of doubly differential electron-atom bremsstrahlung cross sections for energies in the keV region and elements with atomic numbers 6, 13, 52, 73 and 79. Thin targets were irradiated at the low-energy beam line of the Sao Paulo Microtron with 20, 50, 75 and 100. keV electrons. For each element and energy, the photon spectra were collected simultaneously with three HPGe detectors at the emission angles of 35 degrees, 90 degrees and 131 degrees. The deconvolution of the bremsstrahlung spectra was done adopting an analytical model for the spectrometers' response functions. The resulting doubly differential cross sections are compared with the available partial-wave calculations of ordinary bremsstrahlung. Based on this comparison, we discuss some features of the experimental spectra that might be related to the emission of polarization bremsstrahlung.