Material Type  

 학위논문

 

0017161355

Date and Time of Latest Transaction  

20250211151345

ISBN  

9798384447382

DDC  

539.76

Author  

Christensen, Alex Bitz.

Title/Author  

A Conservative First-Collision Source Treatment for Ray Effect Mitigation in Discrete-Ordinate Radiation Transport Solutions.

Publish Info  

[S.l.] : University of California, Berkeley., 2024

Publish Info  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Material Info  

105 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-03, Section: B.

General Note  

Advisor: Fratoni, Massimiliano.

학위논문주기  

Thesis (Ph.D.)--University of California, Berkeley, 2024.

Abstracts/Etc  

요약Deterministic transport codes play a fundamental role in the modeling and simulation of neutron transport. One of the most common deterministic methods is the method of discrete ordinates, also known as the Sn method. While offering significant advantages over other deterministic methods or stochastic methods like Monte Carlo, the method of discrete ordinates suffers from non-physical artifacts in its local solution due to its discretization of angle. These artifacts, referred to as ray effects because of their ray-like appearance, tend to be worse in problems with small sources in areas with little scattering. Significant effort has gone into developing methods to mitigate ray effects, such as the first-collision source treatment, which separates the angular flux into the uncollided and collided fluxes and solving them using nontraditional techniques such as ray tracing. Current ray tracing methods typically trace to a set of points inside a zone to compute an overall flux. However, this approach has significant drawbacks, such as a low potential for optimization, as well as not being conservative. A new method has been developed that traces instead to a set of points on each of a zone's surfaces and computes the currents, before using these to obtain the flux. A comparison between these two ray tracing methods shows significant advantages to the new surface method, including inherent particle conservation, similar convergence rate and increased potential for optimization through ray sharing.

Subject Added Entry-Topical Term  

Nuclear engineering.

Subject Added Entry-Topical Term  

Computational physics.

Subject Added Entry-Topical Term  

Nuclear physics.

Subject Added Entry-Topical Term  

Computer science.

Index Term-Uncontrolled  

Discrete ordinates

Index Term-Uncontrolled  

Numerical methods

Index Term-Uncontrolled  

Radiation transport

Index Term-Uncontrolled  

Ray tracing

Index Term-Uncontrolled  

Neutron transport

Added Entry-Corporate Name  

University of California, Berkeley Nuclear Engineering

Host Item Entry  

Dissertations Abstracts International. 86-03B.

Electronic Location and Access  

로그인을 한후 보실 수 있는 자료입니다.

Control Number  

joongbu:658659