Application of Boltzmann Transport Equation solutions to nuclear reactor physics and radiotherapy applications

玻尔兹曼输运方程解在核反应堆物理和放射治疗应用中的应用

• 批准号: RGPIN-2021-03899
• 负责人: Hébert, Alain
• 金额: $ 1.75万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741837
• 关键词: Application; Boltzmann; Transport; Equation; solutions

The aim of this NSERC/DG proposal is to open the lattice code Dragon5 to the characterization of photon and electron transport at the atomic level. Anticipated outcomes of these developments will benefit to two important research fields in Canada: 1. Improvement of the capability of Dragon5 to accurately represent the gamma heating phenomena in nuclear reactors. This capability greatly improves the position of Dragon5 as the future International Standard Toolset (IST) lattice code for CANDU applications in the 2030-2060 time frame. Full-scale nuclear reactors such as CANDUs represent the most serious option to reduce both greenhouse effect and our dependency on fossil fuels on the long term. Nuclear energy is characterized by extremely low lifetime greenhouse gas emission and very high capacity factor. 2. Combining a photon-electron coupled Boltzmann transport equation (BTE) based model with dedicated hardware leads to more accurate dose calculations and improved radiation treatment planning (RTP) in radio-oncology. RTP technologies currently in use all suffer from one problem, be it slowness or inaccuracy, that makes their use suboptimal in the clinic. We plan to develop a new RTP algorithm that combines speed and accuracy. Making such an algorithm available will revolutionize the field of radiotherapy by making it possible to calculate the dose in real time while the patient is lying on the treatment table. These outcomes require advances on four specific sub-projects: D.1 Producing consistent atomic and nuclear data for coupled mechanical statistics Cross section processing capabilities will be extended so as to process the atomic data related to secondary electrons and photons into multigroup data. Other quantities of interest will be generated: the momentum transfer cross section and the stopping power. At the Dragon5 level, the absorbed dose and energy deposition will be computed. D.2 Neutron-electron-photon coupled BTE-BFP based model Dragon5 is presently based on a solution of the BTE for neutrons. Electron transport is described with the Boltzmann-Fokker-Plank (BFP) equation where the particle scattering is assumed to be highly forward peaked and can be approximated with a partial differential operator using Taylor expansion techniques. D.3 Gamma transport in a fuel unit cell or assembly A fraction of the energy produced by fission, radiative capture or radioactive decay is transported by photons, according to a photonic BTE. In some cases, a primary photon causes the releases of an electron and the production of a secondary photon. D.4 Deterministic solution of the coupled BTE-BFP in radiotherapy The second domain of applications is the radiotherapy. Ionizing radiation is used in RTP. The BTE-BFP based model in radiotherapy consists of two coupled equations to describe photon and electron transport. Using a deterministic solution of the coupled based model open the way to perturbation and sensitivity calculations.

该NSERC/DG提案的目的是将晶格代码Dragon5打开，以在原子层的光子和电子传输的特征上打开晶格代码。这些发展的预期结果将使加拿大的两个重要研究领域受益：1。龙5准确地代表核反应堆中伽马加热现象的能力的提高。该功能大大提高了Dragon5作为2030-2060时间范围内CANDU应用程序的未来国际标准工具集（IST）晶格代码的位置。从长远来看，诸如Candus之类的全尺度核反应堆是减少温室效应和我们对化石燃料的依赖的最严重选择。核能的特征是寿命极低的温室气体排放和极高的容量因子。 2。将基于光子 - 电子耦合的玻尔兹曼传输方程（BTE）模型与专用硬件结合在一起，可以在放射线肿瘤学中更准确地计算剂量计算和改进的放射治疗计划（RTP）。当前正在使用的RTP技术都遇到了一个问题，无论是慢还是准确，这使得它们在诊所中使用了次优。我们计划开发一种结合速度和准确性的新RTP算法。提供这样的算法将通过使患者躺在治疗桌上时实时计算剂量，从而彻底改变放射疗法领域。这些结果需要在四个特定的子项目上进行进步：D.1为耦合机械统计的一致的原子和核数据横断面处理能力将扩展，以处理与二次电子和光子相关的原子数据中的多子数据。将产生其他兴趣的数量：动量转移横截面和停止功率。在Dragon5级别，将计算吸收的剂量和能量沉积。 d.2基于BTE-BFP的中子电子 - photon-Photon耦合模型Dragon5目前基于BTE的中子解决方案。电子传输是用玻尔兹曼 - 福克植物（BFP）方程来描述的，其中假定粒子散射是高度向前的峰，并且可以使用泰勒膨胀技术与部分差分操作员近似。 D.3伽马在燃料单元中或组装裂变，辐射捕获或放射性衰减产生的能量的一部分是由光子传输的。在某些情况下，主要光子会导致电子的释放和次级光子的产生。 d.4耦合BTE-BFP在放射疗法中的确定性溶液的第二个应用领域是放射疗法。电离辐射在RTP中使用。放射疗法中基于BTE-BFP的模型由两个耦合方程组成，用于描述光子和电子传输。使用基于耦合模型的确定性解决方案为扰动和灵敏度计算开辟了道路。