skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Superconducting Prototype Cavities for the Spallation Neutron Source (SNS) Project

Conference ·
OSTI ID:828358

The Spallation Neutron Source project includes a superconducting linac section in the energy range from 186 MeV to 1000 MeV. For this energy range two types of cavities are needed with geometrical {beta} values of {beta} = 0.61 and {beta} = 0.81. An aggressive cavity prototyping program is being pursued at Jefferson Lab, which calls for fabricating and testing four {beta} = 0.61 cavities and two {beta} = 0.81 cavities. Both types consist of six cells made from high purity niobium and feature one HOM coupler on each beam pipe and a port for a high power coaxial input coupler. Three of the four {beta} = 0.61 cavities will be used for a cryomodule test in early 2002. At this time four medium beta cavities and one high beta cavity have been completed at JLab. The first tests on the {beta} = 0.61 and {beta} = 0.81 exceeded the design values for gradient and Q value: E{sub acc} = 10.1 MV/m and Q = 5 x 10{sup 9} at 2.1K for the {beta} = 0.61 and E{sub acc} = 12.3 MV/m and Q = 5 x 10{sup 9} at 2.1 K for the {beta} = 0.81. One of the medium beta cavities has been equipped with an integrated helium vessel and measurements of the static Lorentz force detuning have been done and compared to the ''bare'' cavities. In addition two single cell cavities have been fabricated, equipped with welded-on HOM couplers. They are being used to evaluate the HOM couplers with respect to multipacting, fundamental mode rejection and HOM damping as far as possible in a single cell. This paper describes the cavity design with respect to electromagnetic and mechanical features, the fabrication efforts and the results obtained with the different cavities existing at the time of this workshop.

Research Organization:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Sponsoring Organization:
USDOE Office of Energy Research (ER) (US)
DOE Contract Number:
AC05-84ER40150
OSTI ID:
828358
Report Number(s):
JLAB-ACT-01-32; DOE/ER/40150-2853; TRN: US0403942
Resource Relation:
Conference: 10th Workshop On RF Superconductivity (SRF 2001), Tsukuba (JP), 09/06/2001--09/11/2001; Other Information: PBD: 1 Sep 2001
Country of Publication:
United States
Language:
English