Neutron doses due to beam losses in a novel concept of a proton therapy gantry

8th International Particle Accelerator Conference

Talanov, V.^1 ; Kiselev, D.C.^1 ; Meer, D.^1 ; Rizzoglio, V.^1 ; Schippers, J.M.^1 ; Seidel, M.^1 ; Wohlmuther, M.^1

Paul Scherrer Institut, Villigen PSI

5232, Switzerland^1

关键词: Beam energies;    Design constraints;    Neutron dose;    Novel concept;    Novel design;    Particle transport codes;    Proton therapy;    Secondary neutrons;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/874/1/012107/pdf
DOI  :  10.1088/1742-6596/874/1/012107

来源: IOP

【 摘 要 】

A novel design of a gantry for proton therapy is investigated in which a degrader and emittance limiting collimators are mounted on the gantry. Due to the interactions of protons in these components there will be an additional neutron dose at the location where a patient is positioned during a proton therapy. The results of numerical study of this additional dose are presented. Neutron prompt dose at the patient position is estimated through the Monte Carlo simulation using the MCNPX 2.7.0 particle transport code. Secondary neutron and photon fluxes from the distinct beam loss points are taken into consideration and the resulting dose is calculated using realistic estimates of beam losses. The dependence of the dose on the beam energy and individual impacts of each loss point on the total dose at the patient position as well as on critical beam line components are estimated and potential design constraints are discussed. It has been found that compared with a conventional gantry the expected additional dose is higher but the optimization of the beam line configuration and additional shielding shall help to reduce the dose to an acceptable value.