Applications of Triggered Scaler Module for Accelerator Timing

Since 2006, there have been unexpected trigger-failure events during the operation of the Japan Proton Accelerator Research Complex (J-PARC) timing system. However, among the many suspected modules, it has been difficult to find the one with the fault. To find such a faulty module more easily, the triggered scaler module, which was designed as a PLC-type I/O module, was developed. This type of module requires the start signal of the J-PARC main ring (MR) slow cycle (2.48/5.20 s) and the start signal of the rapid cycle (25 Hz) as reference signals, which are generated by the J-PARC timing system. A scaler in the module counts the number of input pulses during a machine cycle, and stores them in memory-buffers. In 2018, the module was evaluated using the trigger for injection kicker and the low-level radio frequency (LLRF) signal of J-PARC MR. The expected results were shown. In 2020, two applications were developed based on a triggered scaler module. The first one, an application for detecting unexpected-trigger events, successfully detected simulated trigger-failure events. The second one, an application for the abort signal of a machine protection system (MPS), showed that the module is capable of visualizing signals based on a relationship with the accelerator cycle. Two applications show possibilities for the development of more customized applications in the future. An idea to develop a portable unexpected-trigger detection system, which can be used in other accelerator facilities, is discussed herein.

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