Computational study of radiation doses at UNLV accelerator facility

Abstract

Abstract.A Varian K15 electron linear accelerator (linac) has been considered for installation at University of Nevada, Las Vegas (UNLV). Before experiments can be performed, it is necessary to evaluate the photon and neutron spectra as generated by the linac, as well as the resulting dose rates within the accelerator facility. A computational study using MCNPX was performed to characterize the source terms for the bremsstrahlung converter. The 15 MeV electron beam available in the linac is above the photoneutron threshold energy for several materials in the linac assembly, and as a result, neutrons must be accounted for. The angular and energy distributions for bremsstrahlung flux generated by the interaction of the 15 MeV electron beam with the linac target were determined. This source term was used in conjunction with the K15 collimators to determine the dose rates within the facility.

High Energy X-ray Source Characterization at 0.450, 3, 6, 9, and 15 MVp

“…Lewis [3] obtained a single energy spectrum and a radial intensity curve for a 4 MV beam by utilizing a series of tally planes. Hodges [4] went a step further and obtained 200 bin energy spectra for solid angles between 0°-90° in 10° increments for a 15 MVp source. Finally, McClanahan [5] utilized tallying planes rather than solid angles to obtain a series of 44 bin energy spectra for angles between 0°-180° in 1° increments for a 22 MVp source.…”