HOM Sensitivity in the PEP-II HER Vacuum Chamber

PDF Version Also Available for Download.

Description

Synchrotron radiation is the main source of vacuum chamber heating in the PEP-II storage ring collider. This heating is reduced substantially as lattice energy is lowered. Energy scans over {Upsilon} energy states were performed by varying the high energy ring (HER) lattice energy at constant gap voltage and frequency. We observed unexpected temperature rise at particular locations when HER lattice energy was lowered from 8.6 GeV ({Upsilon}(3S)) to 8.0 GeV ({Upsilon}(2S)) while most other temperatures decreased. Bunch length measurements reveal a shorter bunch at the lower energy. The shortened bunch overheated a beam position monitoring electrode causing a vacuum breach. ... continued below

Physical Description

3 pages

Creation Information

Weathersby, Stephen; Novokhatski, Alexander; Sullivan, Mike & /SLAC February 10, 2010.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

Synchrotron radiation is the main source of vacuum chamber heating in the PEP-II storage ring collider. This heating is reduced substantially as lattice energy is lowered. Energy scans over {Upsilon} energy states were performed by varying the high energy ring (HER) lattice energy at constant gap voltage and frequency. We observed unexpected temperature rise at particular locations when HER lattice energy was lowered from 8.6 GeV ({Upsilon}(3S)) to 8.0 GeV ({Upsilon}(2S)) while most other temperatures decreased. Bunch length measurements reveal a shorter bunch at the lower energy. The shortened bunch overheated a beam position monitoring electrode causing a vacuum breach. We explain the unexpected heating as a consequence of increased higher order mode (HOM) power generated by a shortened bunch. In this case, temperature rise helps to identify HOM sources and HOM sensitive vacuum chamber elements. Reduction of gap voltage helps to reduce this unexpected heating.

Physical Description

3 pages

Source

  • Contributed to Particle Accelerator Conference (PAC 09), Vancouver, BC, Canada, 4-8 May 2009

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: SLAC-PUB-13877
  • Grant Number: AC02-76SF00515
  • Office of Scientific & Technical Information Report Number: 972252
  • Archival Resource Key: ark:/67531/metadc928296

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • February 10, 2010

Added to The UNT Digital Library

  • Nov. 13, 2016, 7:26 p.m.

Description Last Updated

  • Dec. 15, 2016, 3:28 p.m.

Usage Statistics

When was this article last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Weathersby, Stephen; Novokhatski, Alexander; Sullivan, Mike & /SLAC. HOM Sensitivity in the PEP-II HER Vacuum Chamber, article, February 10, 2010; United States. (digital.library.unt.edu/ark:/67531/metadc928296/: accessed June 23, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.