title: Modification and benchmarking of MCNP for low-energy tungsten spectra.
abstract: The MCNP Monte Carlo radiation transport code was modified for diagnostic medical physics applications. In particular, the modified code was thoroughly benchmarked for the production of polychromatic tungsten x-ray spectra in the 30-150 kV range. Validating the modified code for coupled electron-photon transport with benchmark spectra was supplemented with independent electron-only and photon-only transport benchmarks. Major revisions to the code included the proper treatment of characteristic K x-ray production and scoring, new impact ionization cross sections, and new bremsstrahlung cross sections. Minor revisions included updated photon cross sections, electron-electron bremsstrahlung production, and K x-ray yield. The modified MCNP code is benchmarked to electron backscatter factors, x-ray spectra production, and primary and scatter photon transport.
authors.affiliation: The University of Texas Health Science Center at San Antonio, Radiological Sciences Division, 78284-7800, USA. mercier@usanca-smtp.army.mil
authors.forename: J R
authors.initials: JR
authors.lastname: Mercier
authors.forename: D T
authors.initials: DT
authors.lastname: Kopp
authors.forename: W D
authors.initials: WD
authors.lastname: McDavid
authors.forename: S B
authors.initials: SB
authors.lastname: Dove
authors.forename: J L
authors.initials: JL
authors.lastname: Lancaster
authors.forename: D M
authors.initials: DM
authors.lastname: Tucker
mesh_terms: D000465:Algorithms; D004583:Electrons; D009010:Monte Carlo Method; D017785:Photons; D011871:Radiology / Q000379:methods*; D012542:Scattering, Radiation; D012984:Software; D014414:Tungsten; D014965:X-Rays
chemical_list: D014414:Tungsten