title: Adjoint acceleration of Monte Carlo simulations using TORT/MCNP coupling approach: a case study on the shielding improvement for the cyclotron room of the Buddhist Tzu Chi General Hospital.
abstract: Full-scale Monte Carlo simulations of the cyclotron room of the Buddhist Tzu Chi General Hospital were carried out to improve the original inadequate maze design. Variance reduction techniques are indispensable in this study to facilitate the simulations for testing a variety of configurations of shielding modification. The TORT/MCNP manual coupling approach based on the Consistent Adjoint Driven Importance Sampling (CADIS) methodology has been used throughout this study. The CADIS utilises the source and transport biasing in a consistent manner. With this method, the computational efficiency was increased significantly by more than two orders of magnitude and the statistical convergence was also improved compared to the unbiased Monte Carlo run. This paper describes the shielding problem encountered, the procedure for coupling the TORT and MCNP codes to accelerate the calculations and the calculation results for the original and improved shielding designs. In order to verify the calculation results and seek additional accelerations, sensitivity studies on the space-dependent and energy-dependent parameters were also conducted.
authors.affiliation: National Synchrotron Radiation Research Center (NSRRC), 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 300, Taiwan, Republic of China. srj@nsrrc.org.tw
authors.forename: R J
authors.initials: RJ
authors.lastname: Sheu
authors.forename: R D
authors.initials: RD
authors.lastname: Sheu
authors.forename: S H
authors.initials: SH
authors.lastname: Jiang
authors.forename: C H
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000465:Algorithms; D001822:Body Burden; D003198:Computer Simulation; D017076:Computer-Aided Design; D003205:Computing Methodologies; D017357:Cyclotrons; D006749:Hospital Design and Construction / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D015233:Models, Statistical; D009010:Monte Carlo Method; D049268:Positron-Emission Tomography / Q000295:instrumentation; D011785:Quality Assurance, Health Care / Q000379:methods; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control; D011834:Radiation Monitoring / Q000379:methods*; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods*; D012062:Relative Biological Effectiveness; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012984:Software; D013624:Taiwan