Construction of J-PARC LINAC-RCS beam transport line new vacuum system

Kobayashi, Fuminori; Kamiya, Junichiro   ; Takahashi, Hiroki  ; Suzuki, Yasuo*; Tasaki, Ryuta*

The vacuum equipment in the L3BT beamline of J-PARC LINAC is controlled by the vacuum system in each area divided by beamline gate valves (BLGVs). In the past, the vacuum system controlled the vacuum equipment by area between BLGVs and did not monitor information about the equipment or vacuum pressure between each other. As a result, equipment can be operated regardless of conditions in adjacent areas, causing problems such as sudden deterioration of vacuum pressure in high vacuum areas and equipment failure due to atmospheric inrushes into vacuum equipment in operation. In addition, since all BLGVs are designed to close simultaneously when an interlock (ILK) occurs due to pressure deterioration, BLGVs in areas unaffected by vacuum deterioration are also forced to close. It is necessary to take measures to make BLGVs operate more appropriately in terms of the number of open/close limits and wear. To solve these various problems, it is first necessary to eliminate human error and increase safety by making it possible to monitor information on equipment and vacuum pressure between areas. Furthermore, it is necessary to improve maintainability by automatically controlling each BLGV individually. Therefore, we have modified and constructed the vacuum system control system with the aim of realizing safe and efficient maintenance and operation of the L3BT vacuum system.