# Consequences of bounds on longitudinal emittance growth for the design of recirculating linear accelerators

## Abstract

Recirculating linear accelerators (RLAs) are a cost-effective method for the acceleration of muons for a muon collider in energy ranges from a couple GeV to a few 10s of GeV. Muon beams generally have longitudinal emittances that are large for the RF frequency that is used, and it is important to limit the growth of that longitudinal emittance. This has particular consequences for the arc design of the RLAs. I estimate the longitudinal emittance growth in an RLA arising from the RF nonlinearity. Given an emittance growth limitation and other design parameters, one can then compute the maximum momentum compaction in the arcs. I describe how to obtain an approximate arc design satisfying these requirements based on the deisgn in [1]. Longitudinal dynamics also determine the energy spread in the beam, and this has consequences on the transverse phase advance in the linac. This in turn has consequences for the arc design due to the need to match beta functions. I combine these considerations to discuss design parameters for the acceleration of muons for a collider in an RLA from 5 to 63 GeV.

- Authors:

- Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

- Publication Date:

- Research Org.:
- Brookhaven National Laboratory (BNL)

- Sponsoring Org.:
- USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)

- OSTI Identifier:
- 1188273

- Report Number(s):
- BNL-107126-2015-CP

R&D Project: KBCH139; KB0202011

- DOE Contract Number:
- DE-SC00112704

- Resource Type:
- Conference

- Resource Relation:
- Conference: 6th International Particle Accelerator Conference (IPAC’15); Richmond, VA; 20150503 through 20150508

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 43 PARTICLE ACCELERATORS

### Citation Formats

```
Berg, J. S.
```*Consequences of bounds on longitudinal emittance growth for the design of recirculating linear accelerators*. United States: N. p., 2015.
Web.

```
Berg, J. S.
```*Consequences of bounds on longitudinal emittance growth for the design of recirculating linear accelerators*. United States.

```
Berg, J. S. Sun .
"Consequences of bounds on longitudinal emittance growth for the design of recirculating linear accelerators". United States. https://www.osti.gov/servlets/purl/1188273.
```

```
@article{osti_1188273,
```

title = {Consequences of bounds on longitudinal emittance growth for the design of recirculating linear accelerators},

author = {Berg, J. S.},

abstractNote = {Recirculating linear accelerators (RLAs) are a cost-effective method for the acceleration of muons for a muon collider in energy ranges from a couple GeV to a few 10s of GeV. Muon beams generally have longitudinal emittances that are large for the RF frequency that is used, and it is important to limit the growth of that longitudinal emittance. This has particular consequences for the arc design of the RLAs. I estimate the longitudinal emittance growth in an RLA arising from the RF nonlinearity. Given an emittance growth limitation and other design parameters, one can then compute the maximum momentum compaction in the arcs. I describe how to obtain an approximate arc design satisfying these requirements based on the deisgn in [1]. Longitudinal dynamics also determine the energy spread in the beam, and this has consequences on the transverse phase advance in the linac. This in turn has consequences for the arc design due to the need to match beta functions. I combine these considerations to discuss design parameters for the acceleration of muons for a collider in an RLA from 5 to 63 GeV.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2015},

month = {5}

}