JLab, Newport News, Virginia, USA
A new Injector Cryomodule (INJ CM) aimed to replace the existing Quarter Cryomodule in the CEBAF tunnel has been developed at Jefferson Lab (JLab). It is sched-uled to be first tested in the Cryomodule Test Facility (CMTF) for module performance then the Upgraded Injector Test Facility (UITF) with electron beam. This new cryomodule, hosting a 2-cell and 7-cell cavity, is designed to boost the electron energy from 200 keV to 5 MeV and permit 380 uA - 1.0 mA of beam current. The 2-cell cavity is a new design whereas the 7-cell cavity is refurbished from a low loss cavity from the retired JLab Renascence Cryomodule. The INJ CM adopts quite a few designs from the JLab 12 GeV Upgrade Cryomodule (C100). Examples of this include having the cold mass hung from a spaceframe structure by use of axial and transverse Nitronic rods, cavities to be tuned by scissor-jack style tuners and the end cans are actually modified from C100 style end cans. However, this new INJ CM is not a quarter of the C100 Cryomodule. This paper focuses on the major design features, fabrication and alignment process and testing of the module and its components.
Authored by Jefferson Science Associates, LLC. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for Government purposes.
JLab, Newport News, Virginia, USA
The CEBAF cryomodule rework program has been a successful tool to recover and maintain the energy reach of the original baseline 6 GeV accelerator. The weakest original modules with eight five-cell cavities assembled in four 'pairs', with a specification when new of 20 MV per cryomodule (5 MV/m), are disassembled, re-cleaned with modern techniques and re-qualified to at least 50 MV (12.5 MV/m), (leading to the acronym 'C50'). The cost per recovered MV is much less than building new modules. However over time the stock of weak modules is being used up and the voltage gain per rework cycle is diminishing. In an attempt to increase the gain per cycle it is proposed to rework the cavities by replacing the original accelerating cells with new ones of an improved shape and better material. The original CEBAF HOM and FPC end groups are retained. The goal is to achieve up to 75 MV (18.75 MV/m) for the reworked module ('C75'). We report on the fabrication experience and test results of the first trial pair, containing two such reworked cavities.
JLab, Newport News, Virginia, USA
Cryomodule production for LCLS-II is well underway at Jefferson Lab. This paper explains the process flow for production cavities, from being received at the Test Lab to being assembled onto cavity strings. Taking our facility and infrastructure into consideration, process optimization and process control are implemented to ensure high quality products.