Glenn Cherry

In this paper we present advanced techniques for the construction of half-wave resonator cryomodules. Recent advances in superconducting low-beta cavity design and processing have yielded dramatically improved cavity performance which reduce accelerator cost and improve operational reliability. This improvement has led to the proposal and construction of half-wave resonators by ANL for the acceleration of 0.1 < \beta < 0.5 ions, e.g., the SARAF Phase-II project at SNRC (SOREQ, Israel) and Project-X at Fermilab. These cryomodules build and improve upon designs and techniques recently implemented in upgrades to ATLAS at ANL. Design issues include the ease of assembly/maintenance, resonator cleanliness, operating at 2 or 4 Kelvin, and ancillary system interfacing.

The Argonne National Laboratory Physics Division is in the final stages of a major upgrade to the Argonne Tandem Linear Accelerator System national user facility, referred to as the intensity upgrade. The intensity upgrade project will substantially increase beam currents for experimenters working with the existing ATLAS stable and in-flight rare isotope beams and for the neutron-rich beams from the Californium Rare Isotope Breeder Upgrade. This project includes the replacement of three existing cryomodules, containing 18 superconducting accelerator cavities and 9 superconducting solenoids, with a single cryomodule with seven SC 72.75 MHz accelerator cavities optimized for ion velocities of 7.7% the speed of light and 4 SC solenoids all operating at 4.5 K. This presentation will report: how we minimized the heat load into the 4 K and 80 K coolant streams feeding the cryomodule, a comparison of the calculated and measured static heat loads at 80 K and the mechanical design of the vacuum vessel.