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Title: HOM Couplers for the LHC Superconducting Crab Cavities. DOE-HEP SBIR Fast-Track Final Scientific Report

Abstract

This report summarizes the work completed in the development of higher order mode (HOM) couplers for the LHC superconducting crabbing cavities. Niowave worked with our partners at Old Dominion University (ODU) to take the RF dipole (RFD) copper prototype HOM coupler built in Phase I into a niobium design which was fabricated, including electron-beam welding. Niowave also designed and built a modified straight coupler for the Double Quarter Wave (DQW) cavity. Three copper prototype DQW couplers were built, and shared with Brookhaven National Laboratory and with Jefferson National Laboratory for testing. Brookhaven was able to do HOM damping measurements similar to what has been done with RFD structures, and JLab has used the copper couplers to measure the induced frequency shift due to the coupler installation into the welded DQW cavities. In addition, we have developed, with the help of Old Dominion University, a cryogenic test structure for cooling the RFD couplers to liquid helium temperature and putting RF fields onto them. This cryogenic structure was built, and used to test the RFD HOM couplers with RF fields at 4 K with liquid helium. Also, an RF vacuum window was designed, built and tested, which is needed to handle themore » kW of power expected on the HOMs when in use at CERN. The following pages detail the parts that were fabricated and tested during this reporting period.« less

Authors:
 [1]; ORCiD logo [1];  [1];  [1]
  1. Niowave, Inc., Lansing MI (United States)
Publication Date:
Research Org.:
Niowave, Inc., Lansing MI (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1435444
Report Number(s):
DOE-SC-0013851-Niowave1
DOE Contract Number:  
SC0013851
Type / Phase:
SBIR (Phase II)
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; superconducting, crab cavities, higher order modes,

Citation Formats

Grimm, Terry L., Boulware, Chase H., Yancey, Joseph A., and Hollister, Jerry. HOM Couplers for the LHC Superconducting Crab Cavities. DOE-HEP SBIR Fast-Track Final Scientific Report. United States: N. p., 2018. Web.
Grimm, Terry L., Boulware, Chase H., Yancey, Joseph A., & Hollister, Jerry. HOM Couplers for the LHC Superconducting Crab Cavities. DOE-HEP SBIR Fast-Track Final Scientific Report. United States.
Grimm, Terry L., Boulware, Chase H., Yancey, Joseph A., and Hollister, Jerry. Thu . "HOM Couplers for the LHC Superconducting Crab Cavities. DOE-HEP SBIR Fast-Track Final Scientific Report". United States.
@article{osti_1435444,
title = {HOM Couplers for the LHC Superconducting Crab Cavities. DOE-HEP SBIR Fast-Track Final Scientific Report},
author = {Grimm, Terry L. and Boulware, Chase H. and Yancey, Joseph A. and Hollister, Jerry},
abstractNote = {This report summarizes the work completed in the development of higher order mode (HOM) couplers for the LHC superconducting crabbing cavities. Niowave worked with our partners at Old Dominion University (ODU) to take the RF dipole (RFD) copper prototype HOM coupler built in Phase I into a niobium design which was fabricated, including electron-beam welding. Niowave also designed and built a modified straight coupler for the Double Quarter Wave (DQW) cavity. Three copper prototype DQW couplers were built, and shared with Brookhaven National Laboratory and with Jefferson National Laboratory for testing. Brookhaven was able to do HOM damping measurements similar to what has been done with RFD structures, and JLab has used the copper couplers to measure the induced frequency shift due to the coupler installation into the welded DQW cavities. In addition, we have developed, with the help of Old Dominion University, a cryogenic test structure for cooling the RFD couplers to liquid helium temperature and putting RF fields onto them. This cryogenic structure was built, and used to test the RFD HOM couplers with RF fields at 4 K with liquid helium. Also, an RF vacuum window was designed, built and tested, which is needed to handle the kW of power expected on the HOMs when in use at CERN. The following pages detail the parts that were fabricated and tested during this reporting period.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2018},
month = {3}
}

Technical Report:
This technical report may be released as soon as May 1, 2022
Other availability
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