# A method for obtaining three-dimensional computation equilibrium of non-neutral plasmas using WARP

## Abstract

Computer simulation studies of the stability and transport properties of trapped non-neutral plasmas require the numerical realization of a three-dimensional plasma distribution. This paper presents a new numerical method for obtaining, without an explicit model for physical collisions in the code, a low noise three-dimensional computational equilibrium distribution. This requires both the loading of particles into an idealized distribution and the relaxation from that distribution toward an approximate numerical equilibrium. The equilibrium can then be modified through a slow change of system parameters, to generate other equilibria. In the present work we apply this method to a UC Berkeley experiment on electron confinement in magnetic geometries appropriate for the ALPHA anti-hydrogen experiment, using the three-dimensional Particle-In-Cell code WARP. WARP's guiding center mover and its option to switch between different solvers during a simulation are highly valuable because they speed up the simulations; they enable the practical use of the new technique for generating numerical equilibrium states of trapped nonneutral plasmas.

- Authors:

- Publication Date:

- Research Org.:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

- Sponsoring Org.:
- Accelerator& Fusion Research Division

- OSTI Identifier:
- 928303

- Report Number(s):
- LBNL-256E

Journal ID: ISSN 0021-9991; JCTPAH; TRN: US0804322

- DOE Contract Number:
- DE-AC02-05CH11231

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Computational Physics

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70; COMPUTERIZED SIMULATION; CONFINEMENT; DISTRIBUTION; ELECTRONS; PLASMA; RELAXATION; SIMULATION; STABILITY; TRANSPORT; VELOCITY; WARP Non-Neutral Plasmas

### Citation Formats

```
Wurtele, J., Wurtele, J., Friedman, A., Grote, D.P., Vay, J-L., and Gomberoff, K..
```*A method for obtaining three-dimensional computation equilibrium of non-neutral plasmas using WARP*. United States: N. p., 2006.
Web.

```
Wurtele, J., Wurtele, J., Friedman, A., Grote, D.P., Vay, J-L., & Gomberoff, K..
```*A method for obtaining three-dimensional computation equilibrium of non-neutral plasmas using WARP*. United States.

```
Wurtele, J., Wurtele, J., Friedman, A., Grote, D.P., Vay, J-L., and Gomberoff, K.. Sat .
"A method for obtaining three-dimensional computation equilibrium of non-neutral plasmas using WARP". United States.
doi:. https://www.osti.gov/servlets/purl/928303.
```

```
@article{osti_928303,
```

title = {A method for obtaining three-dimensional computation equilibrium of non-neutral plasmas using WARP},

author = {Wurtele, J. and Wurtele, J. and Friedman, A. and Grote, D.P. and Vay, J-L. and Gomberoff, K.},

abstractNote = {Computer simulation studies of the stability and transport properties of trapped non-neutral plasmas require the numerical realization of a three-dimensional plasma distribution. This paper presents a new numerical method for obtaining, without an explicit model for physical collisions in the code, a low noise three-dimensional computational equilibrium distribution. This requires both the loading of particles into an idealized distribution and the relaxation from that distribution toward an approximate numerical equilibrium. The equilibrium can then be modified through a slow change of system parameters, to generate other equilibria. In the present work we apply this method to a UC Berkeley experiment on electron confinement in magnetic geometries appropriate for the ALPHA anti-hydrogen experiment, using the three-dimensional Particle-In-Cell code WARP. WARP's guiding center mover and its option to switch between different solvers during a simulation are highly valuable because they speed up the simulations; they enable the practical use of the new technique for generating numerical equilibrium states of trapped nonneutral plasmas.},

doi = {},

journal = {Journal of Computational Physics},

number = ,

volume = ,

place = {United States},

year = {Sat Mar 25 00:00:00 EST 2006},

month = {Sat Mar 25 00:00:00 EST 2006}

}