# Enhanced Method for Cavity Impedance Calculations

## Abstract

With the proposal of medium to high average current accelerator facilities the demand for cavities with extremely low Higher Order Mode (HOM) impedances is increasing. Modern numerical tools are still under development to more thoroughly predict impedances that need to take into account complex absorbing boundaries and lossy materials. With the usually large problem size it is preferable to utilize massive parallel computing when applicable and available. Apart from such computational issues, we have developed methods using available computer resources to enhance the information that can be extracted from a cavities? wakefield computed in time domain. In particular this is helpful for a careful assessment of the extracted RF power and the mitigation of potential beam break-up or emittance diluting effects, a figure of merit for the cavity performance. The method is described as well as an example of its implementation.

- Authors:

- Publication Date:

- Research Org.:
- Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC)

- OSTI Identifier:
- 1021852

- Report Number(s):
- JLAB-ACC-09-982; DOE/OR/23177-0729

TRN: US1104068

- DOE Contract Number:
- AC05-06OR23177

- Resource Type:
- Conference

- Resource Relation:
- Conference: PAC09, 4-8 May 2009, Vancouver, BC, Canada

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 43 PARTICLE ACCELERATORS; ACCELERATOR FACILITIES; CAVITIES; COMPUTERS; IMPEDANCE; IMPLEMENTATION; MITIGATION; PERFORMANCE

### Citation Formats

```
Frank Marhauser, Robert Rimmer, Kai Tian, Haipeng Wang.
```*Enhanced Method for Cavity Impedance Calculations*. United States: N. p., 2009.
Web.

```
Frank Marhauser, Robert Rimmer, Kai Tian, Haipeng Wang.
```*Enhanced Method for Cavity Impedance Calculations*. United States.

```
Frank Marhauser, Robert Rimmer, Kai Tian, Haipeng Wang. Fri .
"Enhanced Method for Cavity Impedance Calculations". United States. https://www.osti.gov/servlets/purl/1021852.
```

```
@article{osti_1021852,
```

title = {Enhanced Method for Cavity Impedance Calculations},

author = {Frank Marhauser, Robert Rimmer, Kai Tian, Haipeng Wang},

abstractNote = {With the proposal of medium to high average current accelerator facilities the demand for cavities with extremely low Higher Order Mode (HOM) impedances is increasing. Modern numerical tools are still under development to more thoroughly predict impedances that need to take into account complex absorbing boundaries and lossy materials. With the usually large problem size it is preferable to utilize massive parallel computing when applicable and available. Apart from such computational issues, we have developed methods using available computer resources to enhance the information that can be extracted from a cavities? wakefield computed in time domain. In particular this is helpful for a careful assessment of the extracted RF power and the mitigation of potential beam break-up or emittance diluting effects, a figure of merit for the cavity performance. The method is described as well as an example of its implementation.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2009},

month = {5}

}