Angular Distribution of X-Ray Differential Flux, Ambient and Effective Dose Intensity from 1 to 20 Mev Electron Accelerators
M.S. Singh and K.L. Shingleton (Lawrence Livermore National Laboratory)
Electron accelerators operating in the range from 1 to 20 MeV are extensively used in medicine, industry, research, and are quite common at Lawrence Livermore National Laboratory (LLNL) for doing both physics research and radiography operations. The exact shape of the X-ray spectral intensity as a function of angle for a thin and thick targets was calculated using the LLNL Monte Carlo procedures. The target thickness ranged from a fraction of the radiation length to the full range of the incident electrons. Ambient and effective doses were converted from the calculated fluxes by using the ICRP/ IAEA ambient and effective fluence-to-dose conversion factors. The X-ray fluxes and doses are presented in both tabular and graphical form for ease of use in radiotherapy, X-ray diagnostics, and for accelerator shield-design calculations. The calculated angular dose intensity and X-ray transmission in tantalum for a 9 MeV electron beam onto a tungsten target shows an excellent agreement with the measurements. Results also show a fairly good agreement with the relevant published work of E. A. Burrill, M. J. Burger and S. M. Seltzer. *This work was performed under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48