ANL, Argonne
ANL Physics Division is pursuing a major upgrade of the ATLAS National User Facility. The overall project will dramatically increase the beam current available for the stable ion beam research program, increase the beam intensity for neutron-rich beams from Californium Rare Isotope Breeder Upgrade (CARIBU) and improve the intensity and purity of the existing in-flight rare isotope beam (RIB) program. The project will take place in two phases. The first phase is fully funded and focused on increasing the intensity of stable beams by a factor of 10. This will be done using a new normal conducting, CW RFQ accelerator and replacing three cryostats of split-ring resonators with a single new cryostat of high-performance quarter-wave resonators. To further increase the intensity for neutron-rich beams, we have started development of a high-efficiency charge breeder for CARIBU based on an Electron Beam Ion Source. The goal of the proposed second phase will be to increase the energies and intensities of stable beams, as well as, increase the efficiency and beam current for CARIBU and in-flight RIB beams. The focus of this paper is on innovative developments for Phase I of the project.
ANL, Argonne
Recent developments for cryomodules required for various low- and medium beta- CW ion accelerator projects will be presented. Comparisons of the designs, fabrication technology and assembly procedures of cryomodules will be discussed. To date, development in this area has been mostly for basic science applications, however, there is also considerable interest in ion accelerators for other applications such as national defense, medicine and accelerator driven systems. The outlook for and some development requirements of SRF cryomodules for these applications will be discussed.
Fermilab, Batavia
ANL, Argonne
The superconducting RF (SRF) cavity production program at Fermilab supports 9-cell 1.3 GHz cavity qualification and preparation for assembling cavities into cryomodules, in support of Project X, ILC, or other future projects. Cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic qualification tests which typically include performance diagnostics. The overall goals of the program, facilities and accomplishments are described.
ANL, Argonne
An upgrade project is underway at the ATLAS superconducting RF (SRF) heavy-ion linac at Argonne National Laboratory to dramatically increase the intensity of both stable beams and short-lived isotopes from the CARIBU fission source. The upgrade includes a new normal conducting RFQ injector and an SRF cryomodule consisting of seven high-performance 72.75 MHz quarter-wave cavities optimized for ions with velocity of 0.077c. The module will deliver more than 17.5 MV of accelerating potential over 5 meters and replace three existing split-ring cryomodules. Key to this performance will be a new cavity fast tuning system that replaces the voltage-controlled-reactance (VCX) fast tuner. The recently completed ATLAS upgrade cryomodule installed in June 2009 has a real estate gradient of 14.5 MV over 4.6 meters, the highest for any low-beta cryomodule, however, performance is 40% less than could be achieved without the VCX. As such, the VCX is being replaced with a high-power rf coupler and a fast piezoelectric-based tuner to be used together to control the cavity phase. Cold test results of a prototype power coupler and piezo-tuner are presented here.