Shunt impedance measurement of the APS BBC injector.
The injector test stand (ITS) at Advanced Photon Source (APS) presently incorporates a ballistic bunch compression (BBC) gun, and it is used as a beam source for a number of experiments, including THz generation, beam position monitor testing for the Linac Coherent Light Source (LCLS), novel cathode testing, and radiation therapy source development. The BBC gun uses three independently powered and phased rf cavities, one cathode cell, and two full cells to provide beam energies from 2 to 10 MeV with variable energy spread, energy chirp, and, to an extent, bunch duration. The shunt impedance of an rf accelerator determines how effectively the accelerator can convert supplied rf power to accelerating gradient. The calculation of the shunt impedance can be complicated if the beam energy changes substantially during its transit through a cavity, such as in a cathode cell. We present the results of direct measurements of the shunt impedance of the APS BBC gun on an individual cavity basis, including the cathode cell, and report on achieved gradients. We also present a comparison of the measured shunt impedance with theoretical values calculated from the rf models of the cavities.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 973465
- Report Number(s):
- ANL/ASD/CP-119178; TRN: US1001817
- Resource Relation:
- Conference: 2006 Linear Accelerator Conference (LINAC 06); Aug. 21, 2006 - Aug. 25, 2006; Knoxville, TN
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
High Gradient High Shunt Impedance Accelerating Structure
A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator