document: Deterministic calculations of photon spectra for clinical accelerator targets A method is proposed to compute photon energy spectra produced in clinical electron accelerator targets , based on the deterministic solution of the Boltzmann equation for coupled electron-photon transport in one-dimensional -LRB- 1-D -RRB- slab geometry . It is shown that the deterministic method gives similar results as Monte Carlo calculations over the angular range of interest for therapy applications . Relative energy spectra computed by deterministic and 3-D Monte Carlo methods , respectively , are compared for several realistic target materials and different electron beams , and are found to give similar photon energy distributions and mean energies . The deterministic calculations typically require 1-2 mins of execution time on a Sun Workstation , compared to 2-36 h for the Monte Carlo runs
doc_bio_tags: B I O O O O O O O O O O O O O B I I O O B I I I O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O B I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O
extractive_keyphrases: photon energy spectra deterministic calculations clinical electron accelerator targets boltzmann equation angular range of interest therapy applications relative energy spectra
abstractive_keyphrases: coupled electron-photon transport one-dimensional slab geometry 3-d monte carlo methods linear accelerator therapy planning integrodifferential equation pencil beam source representations