Mini-workshop on beam-line field-emitter particulates in CEBAF SRF linacs

TL1227 (Test Lab)


Test Lab

Rong-Li Geng (Thomas Jefferson National Accelerator Facility)
Goal: Evaluate field-emission impact to operation of CEBAF SRF linacs. Identify the root cause(s) of particulate field-emitters in operational SRF cavities, with a focus on the particulates originating from the UHV beam-line components. Develop solutions for “particulate-free” beam-line components for future SRF linacs as well as mitigations against accumulated field emitter particulates for operational SRF linacs. Topics: • Observations and experiences with beam-line particulates and correlation with field-emission. • Sources of particulates in UHV beam-line components. • Roles of condensed residual gases. • Mechanisms of particulate transportation in UHV beam-lines. • UHV beam-line component design for lowest particulate generation. • UHV beam-line component cleaning, handling, assembly and operation procedure for lowest particulate generation. • Mitigation against field-emitter particulate in operational SRF linacs. • Techniques for removal of accumulated field emission particulates. • UHV beam line-particulate detection technique. • Fast detectors for in operando monitoring of field-emission turn on. Program committee: Rongli Geng (Chair), SRF R&D, AD Arne Freyberger, CEBAF Operation, AD Geoff Krafft, CASA/AD office, AD Tim Michalski, Mechanical Engineering, ED Tony Reilly, SRF Operation, AD