This assume only US2 stage installed in US-DPS and both DS1 and DS2 in DS-DPS
Gas jet max rep rate:
The max rep rate is decided by pulsing the gas jets at different pressure and watching the beamline pressure at the TCAV - CC3073, and the TCAV waveguide ion pumps. The maximum has been designed as the max rate at which no change is seen at either of these locations.
Note - only H2 limits have been checked so far. And these will change when the rest of the US-DPS is installed.
Note 2 - this rep rate does not guarantee appropriate background pressure between shots. This needs to be considered separately.
How to set up DPS:
- Follow the gas jet how to page to get the gas jets ready: How to use gas jet
- Use the plot above to chose the max backing pressure and rep rate
- Ensure 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.
- Start a strip tool and load the file: DPS_Gasjet_Pressures.stp
- Park the beam on TD11
- Insert VVPG:LI20:3160 and VVPG:LI20:VV3250
- Set interlock bypasses on VGXX:LI20:3171:US1 and VGXX:LI20:3259:DS1. These gauges will read high pressure while gas jets are firing.
- Fire the gas jet once and watch the strip chart. If the 3130 and 3291 pressures say below ~1e-5 Torr
- Fire the gas jet for a minute or so and watch the strip chart.
- If all looks good, then stop the gas jets and open the beamline valves
- Fire the gas jets and watch CC3073 pressure. If there is no change, then you are good to fire at will.
Things to watch for:
- If the lone cold cathode gauges shut themselves off, then turn them back on. If pressure reads above 1e-3 Torr then turn it back off.
- If a CC gauges on 3171 or 3259 are cycling on and off, then force them to stay off (or on if it is in a safe pressure zone)
- Change the control mode to Off, then turn CC HV off.
- Watch the PB and oven turbo temperatures
- Watch CC3073 to see if it ever changes.
How to stop everything at the end:
- Stop firing the jets and follow How to use gas jet to shutdown and depressurize the gas jet system.
- Remove the gauge bypasses on VGXX:LI20:3171:US1 and VGXX:LI20:3259:DS1
- Reset any cold cathode gauge "control modes" that were changed back to auto.
- Call ACR and tell them everything has been reset.