Temporary procedure for RHIC pp fill
- Rule of thumb # 1: Be very careful with orbit correction. If not sure, better not do it.
- Rule of thumb # 2: If polarization deteriorates over many fills, it is likely that too many changes have been made. To revert to an earlier one with good polarization is the natural choice.
- Measure AGS polarization on U4 before RHIC fill. The polarization should be
around 40%. If no time to do a measurement before fill, one after should be done. This is especially important since we want to skip Yellow injection measurement for now.
- Make sure rf pump and synchro are on for AGS extraction.
- Check bunch shape before filling. A long bunch is likely causes beam loss along ramp and consequently causes permit pull.
- Fill RHIC with 55 bunches. Intensity should be around 7*10^10. We will push intensity up gradually. So far 7.5*10^10 seems OK. Fill RHIC
with Fill mode (For details please see
Wolfram's instruction on the web). The
spin pattern should be Blue: ++--, Yellow -+-+ (changed on May 27).
- Measure polarization in both Blue and Yellow before ramp (to reduce impact to beam emittance, a 10 million event run is enough at injection, take this run as data run mode). If zero polarization was measured, it is most likely that spin pattern is wrong. Dump and refill. Repeat polarization measurement.
- Ramp pp9.
- Rotator ramp (rot2).
- Measure polarization with data mode for both rings after rotator ramp (20 million events). We have not
establish the criteria to dump store due to low polarization yet. For now, just follow experimenters voting system.
- Cogging (a lot details here have been ignored).
- Beam life time tuning by adjusting working point. Has to react fast!
- IR steering if needed.
- Measure polarization every two hour. Both are in data mode. If WCAN error shows up and pet page does not update, follow Osamu's procedure). There is an xterm open on the most left terminal at mcr-1 console (the polarimeter console), you can start from step 3 in Osamu's procedure there.