U.S.-Western Europe Regional Cooperative Research: NumericalMethods in Particle Transport Theory

该奖项支持北卡罗来纳州的查尔斯·西沃特博士 大学与J. Hovenier博士合作应用数学 阿姆斯特丹自由大学的V. Boffi博士 和C. Devaux和Y.大学校长 里尔。 在粒子中使用分析和计算方法 运输理论，他们正在研究两个基本问题， 辐射传递的一般领域：探照灯问题和 一般极化问题 在这两种情况下，F-N方法，推导出 最初是由Siewert博士在中子输运理论的背景下提出的， 是数值研究的基础。 经典 本文首先研究辐射传递中的探照灯问题 试图构造一个类的高精度数值解 多维运输问题的解决方案 此外，精确分析 和高精度的数值方法将被用来构建和 实现基本问题的计算可行的解决方案， 包括偏振效应的辐射传输模型。 一 包括偏振的通用辐射能量传输模型 效应将用于研究输运理论中的矢量问题 其中对于非方位角地 必须解决对称问题。 Siewert博士有一个杰出的 对线性输运理论的贡献记录和悠久的历史 富有成效的国际合作。 三个外国集团 与他合作的主要研究中心， 辐射传输和数值输运理论， 分享新的数据和数值结果的做法已经确立。 多次散射的探照灯问题和偏振 辐射是四十多年来首次提出的两个重要问题 前，由rasekhar。 它们在以下方面特别具有挑战性： 数值分析方法 根据他们过去的工作和 随着计算机功能的不断增强，预计Siewert博士的 与欧洲同事的持续合作将有助于 这对确定这些问题的最终解决方案具有重大意义。 辐射传输理论中的挑战性问题。 此外该 他们在极化问题上的工作结果可能会提供一个有用的 从观测数据推断物理性质的诊断工具 强度和偏振分布。

This award supports Dr. Charles Siewert of North Carolina State University to collaborate in applied mathematics with Dr. J. Hovenier of the Free University of Amsterdam, Dr. V. Boffi of the University of Bologna, and Drs. C. Devaux and Y. Fouquart of the University of Lille. Using analytical and computational methods in particle transport theory, they are working on two basic problems in the general field of radiative transfer: the searchlight problem and the general polarization problem. In both cases, the F-N method, derived originally by Dr. Siewert in the context of neutron transport theory, is to be the basis of the numerical studies. The classical searchlight problem in radiative transfer will be studied as a first attempt to construct highly accurate numerical solutions to a class of multi-dimensional transport problems. In addition, exact analysis and highly accurate numerical methods are to be used to construct and implement computationally viable solutions to basic problems in radiative transfer models that include polarization effects. A general radiant energy transfer model that includes polarization effects will be used to study vector problems in transport theory where the computational difficulties encountered for non-azimuthally symmetric problems must be resolved. Dr. Siewert has a distinguished record of contributions to linear transport theory and a long history of productive international collaboration. The three foreign groups with which he is collaborating are major centers of research in radiative transfer and numerical transport theory and a basis for sharing new data and numerical results has been well established. The searchlight problem and polarization for multiply scattered radiation are two important problems first proposed over forty years ago by Chandrasekhar. They are particularly challenging in terms of numerical analysis methods. In light of their past work and the increasing power of computers, it is anticipated that Dr. Siewert's continued collaboration with his European colleagues will contribute significantly to the establishment of definitive solutions to these challenging problems in radiative transfer theory. In addition, the results of their work on the polarization problem may offer a useful diagnostic tool in inferring physical properties from observed intensity and polarization profiles.