J-PARCリニアック制御信号分配システムの改修 UPGRADE OF CONTROL SIGNAL DISTRIBUTION SYSTEM AT J-PARC LINAC

Three kinds of timing signals, 12-MHz clock, 25-Hz trigger, and type code (control word), are used in the timing system of J-PARC. The timing signals are generated in the central control room (CCR) and are delivered to each facilities. In the klystron gallery of the linac, these signals are received, divided, and distributed to each station. However, in this distribution system, an optical signal from CCR is transformed to an electrical one by a O/E module and divided by a FANOUT module, and then re-transformed to an optical by E/O module. This system is a source of troubles such as the module failure, the timing trouble of LLRF for temperature drift and so on. Therefore, we would like to update the timing signal distribution system for use of the optical amplifiers and the optical couplers. 1. はじめ