The procedures to vent/pump the S800 Intermediate Image box, and/or filling the PPAC detectors with gas must be done carefully to ensure that the PPACs are not damaged. For instance, before venting the chamber, we have to make sure that the PPACs are empty and equalized with respect to the vacuum in the chamber. In order to avoid errors, an automated gas handling system (II-GHS) was designed to perform these tasks safely. The II-GHS equipment (valves, flow-meter, pipes, isobutane gas bottle. etc.) are located on the west balcony of the top level in the S3 vault (see figure below):
The GHS is operated remotely through CS studio. Its page can be found on the EXP network through FRIB EXP Main → S800 → GHS Pages (Secondary Pages) → Intermediate Image PPAC and is shown below.
The layout of the II-GHS is shown below.
The operational states of the II-GHS are shown in the diagram below.
From the S800 Main Vacuum page, go to the Intermediate Image - RBT_BTS32 D2430 Pumping Station page, and ensure
The TMP can be turned off at this time.
To vent the chamber:
The PPAC pressure S800_GHS:PI_D2431:V_RD_AB should closely follow the chamber pressure RBT_BTS32:BPG_D2430:VP_RD up to about 10 Torr, which is the upper limit of the range of the gauge for S800_GHS:PI_D2431:V_RD_AB.
Ensure
To evacuate the chamber: