The focus of this book deals with a cross cutting issue affecting all particle transport algorithms and applications; verification and validation (V&V). In other words, are the equations being solved correctly and are the correct equations being solved? Verification and validation assures a scientist, engineer or mathematician that a simulation code is a mirror of reality and not just an expensive computer game. In this book, we will learn what the astrophysicist, atmospheric scientist, mathematician or nuclear engineer do to assess the accuracy of their code. What convergence studies, what error analysis, what problems do each field use to benchmark and ascertain the accuracy of their transport simulations. Is there a need for new benchmark problems? Are there experiments that can be used to help validate the simulation results? If not, are there new experiments that could address these issues? These are all questions raised in this proceedings of the Second Computational Methods in Transport Workshop.

Zusammenfassung
In a wide variety of applications, accurate simulation of particle transport is necessary whether those particles be photons, neutrinos, or charged par- cles. For inertial con?nement fusion, where one is dealing with either direct drive through photon or ion beams or indirect drive via thermal photons in a hohlraum, the accurate transport of energy around and into tiny capsules requires high-order transport solutions for photons and electrons. In ast- physics, the life cycle of the stars, their formation, evolution, and death all require transport of photons and neutrinos. In planetary atmospheres, cloud variability and radiative transfer play a key role in understanding climate. These few examples are just a small subset of the applications where an - curate and fast determination of particle transport is required. Computational Methods in Transport Workshop (CMTW) is devoted to providing a forum for interdisciplinary discussions among transport experts from a wide range of science, engineering, and mathematical disciplines. The goal is to advance the ?eld of computational transport by exposing the me- ods used in a particular ?eld to a wider audience, thereby opening channels of communicationbetweenpractitionersinthe ?eld.Theoriginalconceptforthe workshop was born at the SCaLeS (scienti?c case for large scale simulation) meeting held in Washington, DC in June 2003. The discussions at SCaLeS were lively and informative, and it was clear that the opportunity to meet with experts outside of a particular sub?eld created new insights into the problems being discussed.

Inhalt
Verification (Mostly) for High Energy Density Radiation Transport: Five Case Studies.- A General Strategy for Physics-Based Model Validation Illustrated with Earthquake Phenomenology, Atmospheric Radiative Transfer, and Computational Fluid Dynamics.- Spectral Solvers to Non-Conservative Transport for Non-Linear Interactive Systems of Boltzmann Type.- The Art of Analytical Benchmarking.- Implicit Monte Carlo Radiation Transport Simulations of Four Test Problems.- The Prompt Spectrum of a Radiating Sphere: Benchmark Solutions for Diffusion and Transport.- Some Verification Problems with Possible Transport Applications.- Canopy Reflectance Model Benchmarking: RAMI and the ROMC.- Uncertainty and Sensitivity Analysis for Models of Complex Systems.- A Brief Overview of the State-of-the-Practice and Current Challenges of Solution Verification.- Expert Panel Opinion and Global Sensitivity Analysis for Composite Indicators.- A Practical Global Sensitivity Analysis Methodology for Multi-Physics Applications.