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

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

JAEA-Technology 2024-007, 28 Pages, 2024/07

JAEA-Technology-2024-007.pdf:2.52MB

In J-PARC LINAC, the vacuum system is in place to maintain an ultra-high vacuum in the beam transport line (LINAC to 3GeV RCS beam transportation line: L3BT) between the LINAC to the 3GeV synchrotron. The vacuum system is installed in the LINAC and L3BT buildings and consists of vacuum pumps, vacuum gauges, beam line gate valves (BLGVs), and other vacuum. In existing vacuum systems, vacuum equipment is controlled independently for each area, and vacuum equipment can be operated regardless of the status of adjacent areas. This makes it impossible to eliminate erroneous operation due to human error. In addition, when a vacuum deterioration occurs in the beam transport line, the vacuum deterioration ILK signal is transmitted to the BLGV relay unit via the MPS transmission signal, which causes the BLGVs to be forcibly closed. Because the ILK signal transmission range extends to all BLGVs in the L3BT, however, BLGVs in areas unaffected by vacuum deterioration are also forced to close. This could cause problems such as unnecessary open/close operations leading to more frequent maintenance cycles of the BLGVs. In addition, since the BLGV is operated using the MPS signal path, maintenance of the vacuum control system requires work involving the MPS signal path, making it difficult to maintain the vacuum control system alone and making the work complicated. To solve these problems, it is necessary to improve maintainability by separating the signal paths and automatically controlling BLGV separately. Therefore, the vacuum control system was modified and constructed with the aim of realizing a control system that takes into account the safety and efficient maintenance and operation of the L3BT vacuum system. This report summarizes the development and use of the L3BT vacuum system control system.

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

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

no journal, , 

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.