SRF technology at ACCEL for worldwide accelerator projects

Within the last two years activities at ACCEL for international accelerator projects using superconducting cavities have steadily increased. We report on our production work for CERN (HOM couplers for LHC cavities), DESY (TESLA cavities and couplers), Forschungszentrum Jülich (turn key low beta SRF module), SRRC, CLS and Cornell (turn key 500 MHz SRF modules. The production a superconducting Landau accelerator module for BESSY has started recently. In addition studies are under way for a superconducting 40 MeV proton/deuteron linac and for superconducting low beta multi gap structures. 1 CAVITY AND ACCELERATOR MODULE FABRICATION 1.1 Superconducting Cavities for the TESLA Test Facility A series of 24 TESLA type cavities (1.3 GHz, 9 cell cavities) has been fabricated and delivered by ACCEL. The test results after chemical preparation and high pressure water rinsing at DESY achieve or even exceed the target values. All cavities showed an Eacc > 25 MV/m with a quality factor above 5*10. Figure 1: Performance of TESLA cavities delivered by ACCEL 1.2 Superconducting Cavities for the Spallation Neutron Source In August 2001 ACCEL was awarded with the contract for manufacturing all cavities for the superconducting part of the SNS project. The contract covers the production of 35 medium beta cavities (β=0.61) and 75 high beta cavities (β=0.75) with a frequency of 700 MHz. The production scope includes the rf tuning as well as the internal and external chemical preparation (removal of surface damage layer). Prototypes of the cavities have been manufactured by Jefferson Laboratory and shown performance well above the design values. The specified values are shown in table 1. Figure 2: Prototype of medium beta cavity for SNS produced by JLAB (courtesy Jefferson Laboratory) Table 1: Design Values SNS Cavities Cavity β Eacc(@ 2.1K) Q0 0.61 10.1 MV/m 5*10 0.75 12.5 MV/m 5*10 1.3 Superconducting Modules for Storage Rings Up to now six cavities of the Cornell design have been produced by ACCEL. First cryogenic rf tests of the cavities have been completed. Figure 3: Cornell type cavities fabricated by ACCEL Meanwhile ACCEL was awarded with contracts for building six turn key 500 MHz SRF modules for SRRC (Taiwan Light Source), CESR (Cornell University) and The 10 Workshop on RF Superconductivity, 2001, Tsukuba, Japan