Diagnostics with quadrupolar pick-ups
DOI:
https://doi.org/10.23732/CYRCP-2020-009.130Abstract
The spectrum of a quadrupolar pick-up gives access to coherent second-order modes of a beam in a non-invasive way. The signature of bunched beams not only features the first-order and second-order dipolar modes, but also most notably (1.) bands of even envelope modes, (2.) odd (skew) envelope modes and (3.) coherent dispersion modes. The odd (skew) envelope modes can provide information on linear coupling and mismatch thereof. The tunes of even envelope modes and the coherent dispersion modes shift significantly with space charge and can thus provide a measurement thereof.
The paper presents measurements of the various modes at the CERN Proton Synchrotron, demonstrates how the spectral amplitudes depend on the mismatch conditions, and suggests a new, alternative way to quantify space charge at high brightness conditions via the coherent dispersion mode.
Downloads
Published
Issue
Section
License
Copyright (c) 2021 CERN
This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish with this publication agree to the following terms:
- CERN retains copyright and publishes the work licensed under the Creative Commons Attribution License 4.0 that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this series.
- Authors are able to enter into separate, additional contractual arrangements for distribution of the published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this series.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).