Angular distribution of thick-target bremsstrahlung produced by electrons with initial energies ranging from 10 to 20-keV incident on Ag

TL;DR

This study measures the angular distribution of bremsstrahlung produced by 10-20 keV electrons on thick silver targets, revealing anisotropy near the initial electron energy and isotropy at lower photon energies, with results aligning with theoretical models.

Contribution

First experimental investigation of bremsstrahlung angular distribution on thick targets at low electron energies, comparing results with theoretical predictions and Monte Carlo simulations.

Findings

Anisotropic bremsstrahlung distribution at photon energies near initial electron energy.

Isotropic distribution as photon energy decreases relative to initial energy.

Experimental data agrees with theoretical and Monte Carlo models.

Abstract

Experimental results are presented comparing the intensity of the bremsstrahlung produced by electrons with initial energies ranging from 10 to 20-keV incident on a thick Ag target, measured at forward angles in the range 0 degrees to 55 degrees. When the data are corrected for attenuation due to photon absorption within the target, the results indicate that the detected radiation is distributed anisotropically only at photon energies, k, that are approximately equal to the initial energy of the incident electrons, Eo. The results of our experiments suggest that as k /Eo goes to 0, the detected radiation becomes essentially isotropic due primarily to the scattering of electrons within the target. A comparison to the theoretical work of Kissel et al. [At. Data Nucl. Data Tables 28, 381 (1983)] suggests that the angular distribution of bremsstrahlung emitted by electrons incident on thick targets is similar to the angular distribution of bremsstrahlung emitted by electrons incident on free-atom targets only when k /Eo is approximately equal to 1. The experimental data are also in approximate agreement with the angular distribution predictions of the Monte Carlo program, PENELOPE.