...
- Verify vacuum conditions in the IP of approximately 1e-6 Torr.
- Verify both US-DPS and DS-DPS pumps are running and operating as normal. Also check VPIO:LI20:3164 to ensure the ion pump is on.
- This is how the DPS looks under nominal operation:
- Start a strip tool and load the file: DPS_Gasjet_Pressures.stp
- Find the VGCM:LI20:M3203:PMONRAW pressure - this is the 10 Torr capacitance manometer gauge that will provide the IP pressure.
- Verify the oven fill line is connected to the gas bottle of the desired gas type and the flow regulator is closed.
- Gas bottles and flow regulator location:
- Set up to the mass flow controller: How to use MKS mass flow controller (DPS)
- Open the fill valve #1 to evacuate the line and leave open for several minutes then close.
- Open the gas bottle and set the regulator to 10 psig.
- Read the gas bottle pressure and ensure that there is enough gas to last for the intended fill.
- Previous measured rate of He usage at 5 Torr IP pressure = 165 psi/day (one full 2500 psi bottle drained in ~15 days)
- Verify gas bottle on fill line #2 is closed and that the fill valve for this line is closed. Ensure that the IOTA controller in FKG20-24 is turned OFF.
- Open the fill valve #1 and set start flow rate on the flow regulator to 0.1 SCFH with the MFC to purge He through the fill line for several minutes.
- Close the fill valve to stop the flow and evacuate the IP again.
- If operating the Li oven, follow the E300 procedure to prepare the Li oven for a static fill.
...
- Close angle valve VV3202 isolating the plasma beamline from the plasma turbo
- Close valve FV-PB on the foreline of the Picnic Basket. Turn off Picnic Basket turbo
- Close Beryllium window valve VV3208
- Adjust the flow regulator MFC to reach the desired fill pressure. There is a slow so make changes slowly.
- In previous tests a setting of ~0.8 SCFH or ~400 on MFC results ~5 Torr for He
- It will likely take 5-10 minutes for the pressure to approach the pressure setpoint. Make small changes and wait for 5-10 minutes for the pressure to stabilize before proceeding with more adjustments.
- Continue to monitor the IP pressure and make minor adjustments to the flow rate if necessary.
...