Speaker
Description
A new bunch lengthening cryomodule based a sin-gle-cell superconducting (SC) cavity operating at the 4th harmonic (1408 MHz) of the main RF has been installed into Argonne’s Advanced Photon Source (APS) storage ring as part of the U.S. DOE APS Up-grade project. The beam-driven system will be used to improve the Touschek lifetime by increasing the bunch length by up to several times. The 2-meter-long cryomodule is installed into one half of an APS straight section. The cavity will run at 2.1 K and pro-vide up to 1.3 MV of potential for bunch lengthening in a storage ring mode with a beam current of 200 mA evenly distributed into 48 bunches. System features include a pneumatic slow mechanical tuner and a pair of adjustable RF power couplers to adjust both the frequency and the loaded quality factor, providing a means of stabilizing the beam over a range of beam currents and fill patterns. Beam induced higher-order modes (HOMs) will be extracted along the beam axis and damped using a pair of room temperature silicon carbide absorbers. Cryogenic cooling is being provid-ed by a new 4.3 K liquid helium refrigerator combined with vacuum pumping and J-T expansion inside the cryomodule. We summarize the system features and report some results of initial cool down, testing, and measurements with beam.
| Region represented | North America |
|---|---|
| Paper preparation format | Word |
