FRIB, East Lansing, Michigan, USA
The Facility for Rare Isotope Beams (FRIB) includes two types of half wave SC resonators (HWR) operating at 322MHz. The fundamental power couplers used to transmit RF power into the HWRs commonly suffer from multipacting which can result in long conditioning times. A bias tee can be used to apply a high voltage to the couplers to help alleviate multipacting. A production version of the bias tee was commissioned for use at FRIB. The bias tee went through several design revisions to diagnose and correct thermal dissipation issues. This paper will discuss details of design and challenges faced during production validation of the bias tee.
FRIB, East Lansing, Michigan, USA
Some Python based tools have been developed at the Facility for Rare Isotope Beams (FRIB) for the ease of operation and management of the low level radio frequency (LLRF) controllers. Utilizing the rich features in Python, some tasks can be easily applied to a whole segment, one type of cryomodule (CM), a specific cryomodule or individual cavities grouped by a complex custom query. The tasks include, for example, 1) testing interface connections between various sub-systems prior to an operational run; 2) setting, checking and saving/restoring parameters during and after an operational run; 3) updating LLRF controller firmware and software during maintenance. With these tools, routine manual tasks are streamlined to achieve significantly greater efficiency in terms of scalability, time, memory and network resources. Considering channel access security, beam on/off status etc., the strategy of choosing either input/output controller (IOC) or Python for the implementation of certain tasks is also discussed in the paper.