R&D (FilterCavity)
RyutaroTakahashi - 09:41, Wednesday 23 October 2019 (1761)
BS TMP trouble

(Log on 21st)

As reported in the Elog, the BS TMP was failed on 18th. The pump was restarted, but it has problems.

  1. Started the RP in the back side of TMP.
  2. Opened the angle valve of RP.
  3. Reset the TMP and started it.
  4. The pressure in BS chamber was 1.8x10-6 Torr.
  5. After the rotation speed of TMP reached 600 Hz, opened the gate valve for BS chamber.
  6. The pressure was increased to 2.0x10-6 Torr. This means that the outgassing rate of TMP itself is too large.
  7. Closed the gate valve and the angle valve.
  8. Stoped the TMP and the RP.
  9. Checked the RP. The inline filter between the TMP and the RP was filled by oile. The vapor of oile might contaminate the TMP.
  10. Replaced the RP system (RP itself, inline filter, bellows, angle valve) to the other from the EW arm.
  11. To declease the outgassing rate of TMP, a baking is necessary. Binded the TMP with the ribbon heater and attached the thermometer.
  12. Restarted the TMP and the RP closing the gate valve.
  13. The temparature must be lower than 120 oC. The heater was turned on/off manually around 110oC for 30 min.
  14. According to the manual of TMP, 4 hours are necessary for the baking. Will continue the baking on 23rd.
Comments related to this report
RyutaroTakahashi - 17:44, Wednesday 23 October 2019 (1764)
I baked out the TMP for only 20 min today. It was hard to keep the temperature of heater manually. Thermostat is necessary to control the heater automatically.
 
In the other hand, the TMP was working through two days. The outgassing rate should be decreased even though the baking was not implemented. The penning gauge shows 1.9~2.0 x10-6 Torr in each case;  open/close the gate valve. It's strange. The gauge would not be working.