Further RF measurements on the superconducting 217 MHz CH demonstrator cavity for a CW linac at GSI

F Dziuba,T Conrad,A Schnase,K Aulenbacher,S Lauber,M Schwarz,V Gettmann,M Basten,M Miski-Oglu,C Burandt,S Yaramyshev,J Salvatore,H Podlech,M Heilmann,W Barth,M Busch,T Kürzeder,J List

doi:10.1088/1742-6596/1350/1/012185

Abstract

Recently, the first section of a superconducting (SC) continuous wave (CW) linac has been extensively tested with heavy ion beam from the GSI High Charge State Injector (HLI). During this testing phase, the reliable operability of 217 MHz multi-gap crossbar-H-mode (CH) cavities has been successfully demonstrated. The SC 217 MHz CH cavity (CH-0) of the demonstrator setup accelerated heavy ions up to the design beam energy and even beyond at high beam intensities and full transmission. This worldwide first beam test with a SC CH cavity is a major milestone on the way realizing the entire SC CW linac project. In this contribution further RF measurements on the cavity are presented providing full characterization of the RF structure CH-0.

Highlights

Within the scope of building a new SC continuous wave (CW) linac at GSI an R&D program has been initiated in collaboration with the Helmholtz Institute Mainz (HIM) and the Institute of Applied Physics (IAP) of Goethe University Frankfurt in 2010
Summary & outlook In future the existing UNILAC (UNIversal Linear ACcelerator) [15, 16, 17, 18] at GSI will be exclusively used as an injector for FAIR (Facility for Antiproton and Ion Research) providing short pulse high intensity heavy ion beams at low repetition rates [19, 20, 21]
The SC 217 MHz CH-0 cavity has been tested at GSI with low level RF power at 4.2 K

Summary

Introduction

Horizontal cold test at 4 K Beam test with power coupler Design cw LINAC 4. RF measurements with 2 kW power coupler After the final RF test with low level power the whole demonstrator setup was modified and prepared for beam commissioning. The cavity was dismounted from the cryomodule and replacement of the input coupling probe by a 2 kW power coupler has been accomplished inside the clean room at GSI.

Results

Conclusion