Run Plan for Kaon LT Luminosity Scan

Goal

The electrons in the HMS will be used to monitor cryotarget boiling, while the positive polarity SHMS will be used to investigate the reliability of hadron tracking efficiencies at high rates. We will use three different targets:

• standard 10cm LH₂
• C (z=1.5% RL) - maximum current 65uA
• Al dummy - maximum current 40uA

Initial Setup

1. Set PS1 and PS3 DAQ rates to 1.5kHz, to give a total rate to disk of about 3kHz.
2. Increase EDTM trigger rate to 10kHz, to ensure that after prescaling there are 10k-100k EDTM events per run.
3. Ensure the raster is on (2x2)

During scan

1. Monitor number of EDTM events: to ensure 10k-100k events/run
2. Try to get runs with minimum of beam trips: In particular, there might be a high number of trips due to the SHMS diffusor ion chambers at this small angle when running above 50uA. MCC can fix this by selectively changing the thresholds in the offending chambers. See here for more info.
3. Be wary of DC HV trips in SHMS: we are at a small angle, for some of the higher currents we will have to switch off the HV for the SHMS DCs
4. Use the highest current we can get: If MCC can't reach a current, we take data at the highest current that they can reach instead. This might mean we need to skip the highest luminosity settings.

Sweep 1

0. Preparation

Rotate HMS to 12.50 degrees, everything else is unchanged.

1. P_HMS = -3.266 GeV/c (unchanged)
2. θ_HMS = 12.50 deg (NEW)
3. P_HMS = 6.842 GeV/c (unchanged)
4. θ_HMS = 6.49 deg (unchanged)
5. LH₂target (unchanged)