The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

Abstract

The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay γ-quanta by the residuals in the activated structures and scoring the prompt doses of these γ-quanta at arbitrary distances from those structures. The Fer-miCORD code system has been benchmarked against similar algorithms based on other code systems and against experimental data from the CERF facility at CERN, and FermiCORD showed reasonable agreement with these. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

Mu2e-II: Muon to electron conversion with PIP-II

“…In the case of the residual dose, we made a similar assumption on the energy dependence to scale the Mu2e baseline dose to the Mu2e-II one. In the baseline Mu2e, the following typical radiation quantities were calculated: 1) the residual dose in air 1 foot away from the west wall in the PS hall will be ∼ 300 mrem/hr [106] (expected to be ∼ 6.2 rem/hr in Mu2e-II based on the assumptions discussed above); 2) the peak prompt dose above the berm (PS Hall area) will be ∼ 3-10 mrem/hr in baseline Mu2e [107] (206 mrem/hr in Mu2e-II); the prompt dose above the berm away from the peak (∼ 4 meters South) can become ∼ 0.01 mrem/hr into Mu2e [107] (∼ 0.2 mrem/hr in Mu2e-II). Among mitigation strategies one can consider increasing the berm and/or fencing in the controlled zone area.…”

“…A preliminary assessment of the residual Mu2e radiation in the PS Hall (the hottest area) can be based on the MARS15 and FermiCORD [106] simulation results shown in Figure 20. The residual dose from several sources (target, endcap, beam dump, walls, the floor, the ceiling) on the target elevation after 1 year of irradiation and 60 days of cooling will be ∼ 10 mSv/hr (1 Rem/hr) FIG.…”