Physics Division Research Highlights
New Cryomodule Boosts ATLAS Beam Energy
A new, state-of-the-art cryomodule containing seven superconducting quarter-wave cavities has been developed at Argonne for the ATLAS energy upgrade. It increases the ATLAS maximum beam energy by approximately 30%, which will benefit many nuclear physics experiments using both stable and radioactive CARIBU beams. With this achievement, our Division continues to lead the world in the superconductivity technology for the acceleration of heavy-ion beams.
The design incorporates several innovative features. The cryomodule separates the cavity vacuum space from the insulating vacuum – a first for TEM cavities. It cancels the beam steering effects due to RF fields. Moreover, novel cleaning techniques have been applied to achieve low-particulate cavity surfaces. These features have resulted in higher accelerating fields and cavity voltages (total of 14.5 MV), better than any other TEM-cavity linacs around the world. They are also essential for long-term reliable operation.
The performance of the new cryomodule and its cavities has been reported at several recent international conferences. For example, Joel Fuerst presented an invited talk on this development at the 14th International Conference on RF Superconductivity on September 21st, 2009.
Cavity string suspended from the lid, ready to be dropped into the vacuum vessel.