Operation status and analysis of the new production target at J-PARC Hadron Experimental Facility

A new secondary-production target for the Hadron Experimental Facility at J-PARC has been installed in Nov., 2019. The target is made of gold and is indirectly cooled by water through a copper block. The target is designed to be capable of a primary-proton beam power up to 95 kW for a 5.2-s repetition cycle, in which a beam-extraction period is 2 s. A first beam commissioning with the new target has been successfully carried out with the beam power up to 51 kW in May and June, 2020. Soundness of the target is mainly monitored by temperatures of the gold. In the new target, 24 thermocouples in total are attached on the gold and are recorded every 100 msec. In addition to the soundness monitoring, a transverse temperature balance, which indicates a heat-generation center position in the gold, is expected to be correlated with a beam-injection position. In fact, we have clearly found the good correlation between the temperature balance and the beam position in the beam-commissioning data. Furthermore, a fairly fast transition of the position even during one spill has been observed. In this report, the commissioning results of the target including the detail temperature analysis are presented. (author)