RHIC Superconducting Accelerator and Electron Cooling Group

RHIC SRF 56 MHz Storage Cavity

The C-AD SRF and Electron Cooling Group is developing a SRF cavity to serve as a storage cavity at RHIC. The motivation is:

  • Provide a large voltage at minimal power and low cost and space requirements (2.5 MV) at a low frequency, conservatively from single cavity
  • Huge bucket
    • Adiabatic capture directly from 28 MHz cavity, eliminate the generation of satellite bunches
    •  Keeps ions in one bucket -reduce spill and background, improve luminosity in the detector vertex
    •  Improve luminosity by allowing a shorter beta function at IP due to reduced hourglass effect
  • SRF cavities are stable
  • Improve vacuum in RF sector (pressure rise)
  • Somewhat lower RHIC impedance (fewer cavities)

56 MHz cavity 3-D graphic

For more information see the following:

  • presentations in the February 2008 Machine Advisory Committee:

See also report by Nathan Towne on stability issues of RHIC with the 56 MHz SRF cavity.

International External Review Committee

An International Committee reviewed the 56 MHz cavity design on January 8-9, 2009.

Presentations and other information on the review can be found at:


Supplemental Material

HOM Damper Mechanical Engineering

56 MHz Cavity Project Milestones

56 MHz Cavity Project Overall Schedule

Welcome, Derek Lowenstein

Introduction, Ilan Ben-Zvi

Beam stability of RHIC with the 56 MHz cavity, Mike Blaskiewicz

Cavity Electromagnetic Design, Xiangyun Chang

Fundamental - Mode Damper, Eunmi Choi

Fundamental and HOM Damper Designs, Eunmi Choi

Multipacting Studies, Damayanti Naik

3D Multipacting Calculations, Jőrg Kewisch

Resonator Mechanical Design and Tuner Mechanical Design, Chien Pai

Cryogenic System, Roberto Than

Chemistry and Testing, Andrew Burrill

Answers to Committee follow-up questions

56MHz Cavity Fabrication Procedures

Cryomodule Assembly


Fundamental Damper


The review summary report is here.


RHIC A.P. Notes related to the 56 MHz SRF cavity:

C-A/AP/314 7/08

Summary on the fundamental mode damper experiments of the 56 MHz SRF cavity  E. M. Choi, H. Hahn

C-A/AP/315 7/08

Capacitive fundamental power coupler and pickup for the 56 MHz SRF cavity  E. M. Choi, H. Hahn

C-A/AP/319 8/08 Higher Order Mode Damper Study of the 56 MHz SRF Cavity,  E.M. Choi, H. Hahn
C-A/AP/321 8/08 Higher order model power calculation of the 56 MHz SRF cavity   E.M. Choi
C-A/AP/331 10/08

Geometric Optimization of the 56MHz SRF Cavity and its Frequency Table, X. Chang, I. Ben-Zvi

C-A/AP/332 10/08

IBS and Expected Luminosity Performance For RHIC Beams At Top Energy With 56 MHz SRF Cavity, A. Fedotov

C-A/AP/333 10/08

RHIC Performance with 56 MHz RF and Gold Ion Beams Pre-cooled at Lower Energy  A. Fedotov

C-A/AP/337 1/09
Superconducting Storage Cavity for RHIC,  I. Ben-Zvi
C-A/AP/339 1/09
IBS and Potential Luminosity Improvement for RHIC Operation Below Transition Energy, A. Fedotov
C-A/AP/341 1/09
Longitudinal Stability Calculations, M. Blaskiewicz
C-A/AP/342 1/09
56 MHZ Cavity Prototype Measurements, H. Hahn, E. Choi
C-A/AP/343 1/09
Multipacting simulation study for 56 MHz Quarter Wave Resonator using 2D code, D. Naik, I. Ben-Zvi
C-A/AP/344 1/09
Cryogenic and Cryostat System for the 56 MHZ SRF Cavity, R. Than


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Last Modified: March 9, 2009

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