# Coupled electron-photon radiation transport

## Abstract

Massively-parallel computers allow detailed 3D radiation transport simulations to be performed to analyze the response of complex systems to radiation. This has been recently been demonstrated with the coupled electron-photon Monte Carlo code, ITS. To enable such calculations, the combinatorial geometry capability of ITS was improved. For greater geometrical flexibility, a version of ITS is under development that can track particles in CAD geometries. Deterministic radiation transport codes that utilize an unstructured spatial mesh are also being devised. For electron transport, the authors are investigating second-order forms of the transport equations which, when discretized, yield symmetric positive definite matrices. A novel parallelization strategy, simultaneously solving for spatial and angular unknowns, has been applied to the even- and odd-parity forms of the transport equation on a 2D unstructured spatial mesh. Another second-order form, the self-adjoint angular flux transport equation, also shows promise for electron transport.

- Authors:

- Publication Date:

- Research Org.:
- Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)

- Sponsoring Org.:
- US Department of Energy (US)

- OSTI Identifier:
- 750243

- Report Number(s):
- SAND99-2799C

TRN: US0001576

- DOE Contract Number:
- AC04-94AL85000

- Resource Type:
- Conference

- Resource Relation:
- Conference: Advances in Reactor Physics and Mathematics and Computation into the Next Millennium, Pittsburgh, PA (US), 05/07/2000--05/11/2000; Other Information: PBD: 17 Jan 2000

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; ELECTRONS; CHARGED-PARTICLE TRANSPORT; PHOTON TRANSPORT; PARALLEL PROCESSING; THREE-DIMENSIONAL CALCULATIONS; MONTE CARLO METHOD; I CODES; MESH GENERATION

### Citation Formats

```
Lorence, L, Kensek, R P, Valdez, G D, Drumm, C R, Fan, W C, and Powell, J L.
```*Coupled electron-photon radiation transport*. United States: N. p., 2000.
Web.

```
Lorence, L, Kensek, R P, Valdez, G D, Drumm, C R, Fan, W C, & Powell, J L.
```*Coupled electron-photon radiation transport*. United States.

```
Lorence, L, Kensek, R P, Valdez, G D, Drumm, C R, Fan, W C, and Powell, J L. Mon .
"Coupled electron-photon radiation transport". United States. https://www.osti.gov/servlets/purl/750243.
```

```
@article{osti_750243,
```

title = {Coupled electron-photon radiation transport},

author = {Lorence, L and Kensek, R P and Valdez, G D and Drumm, C R and Fan, W C and Powell, J L},

abstractNote = {Massively-parallel computers allow detailed 3D radiation transport simulations to be performed to analyze the response of complex systems to radiation. This has been recently been demonstrated with the coupled electron-photon Monte Carlo code, ITS. To enable such calculations, the combinatorial geometry capability of ITS was improved. For greater geometrical flexibility, a version of ITS is under development that can track particles in CAD geometries. Deterministic radiation transport codes that utilize an unstructured spatial mesh are also being devised. For electron transport, the authors are investigating second-order forms of the transport equations which, when discretized, yield symmetric positive definite matrices. A novel parallelization strategy, simultaneously solving for spatial and angular unknowns, has been applied to the even- and odd-parity forms of the transport equation on a 2D unstructured spatial mesh. Another second-order form, the self-adjoint angular flux transport equation, also shows promise for electron transport.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2000},

month = {1}

}