Field Emission and Consequences as Observed and Simulated for CEBAF Upgrade Cryomodules

Conference · Sun Sep 01 00:00:00 EDT 2013

OSTI ID:1164404

Marhauser, Frank; Johnson, Rolland; Rodriguez, Rodolfo; Degtiarenko, Pavel; Hutton, Andrew; Kharashvili, George; Reece, Charles; Rimmer, Robert

High gamma and neutron radiation levels were monitored at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Laboratory (JLab) after installation of new cavity cryomodules and initial test runs in the frame of the ongoing 12 GeV upgrade program. The dose rates scaled exponentially with cavity accelerating fields, but were independent of the presence of an electron beam in the accelerator. Hence, field emission (FE) is the source of origin. This has led to concerns regarding the high field operation (100 MV per cryomodule) in the future 12 GeV era. Utilizing supercomputing, novel FE studies have been performed with electrons tracked through a complete cryomodule. It provides a principal understanding of experimental observations as well as ways to mitigate FE as best as practicable by identification of problematic cavities.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1164404
• Report Number(s): JLAB-ACC-13-1807; DOE/OR/23177-3235
• Resource Relation: Conference: SRF 2013, 23-27 Sept 2013. Paris, France
• Country of Publication: United States
• Language: English