NSRRC Activity Report 2023

Facility Development and Status 091 Downtime and Failure Analysis of the TLS In 2023, there were 23 beam trips and 48.45 hours of downtime in total. A SRF system needs to provide high power to the stored beam and operate at 4.5 K with a cryogenic system, which is complicated and the most deteriorated system; additionally, this system requires the largest portion of the annual trips and exhibits a fast recovery time. The contributions from each subsystem of the TLS facility are illustrated in Figs. 2 and 3 . The major downtime contributes to the Linac system as it malfunctions, which cannot accelerate electrons to adequate beam energy for injection into the booster. This process transferred the top-up injection mode to decay mode at the storage ring because a stored current less than 300 mA was defined as downtime. In terms of downtime, the 2 nd -ranking factor is the power supply, and some of these power supplies were in service for more than 30 years. Alternative solutions to replace troublesome and aging power supplies are under evaluation. Fig. 1 : Annual beam stability index of 0.1%, availability, and MTBF of the TLS. Fig. 2 : Rations of beam trips for the TLS accelerators in 2023. RF stands for Radio Frequency; PS stands for Power Supply; and I&C stands for Instrumentation & Control. (23 trip events in total) Fig. 3 : Downtime distribution for the TLS accelerators in 2023. The major failure times are as follows: LINAC, 19.99 hours; PS, 10.45 hours; RF, 6.42 hours; and other, 6.20 hours. (Accumulated for 48.45 hours in total)