May 29th
From Hall A Wiki
Topics
- Optics
- Rey checked the current optics matrix with Hydrogen data (plot target variables vs invariant mass etc), compared with GMp latest optics (lower order). It's hard to tell what the GMp version improved. Or suggested to check more carefully (with p_miss).
- Shujie calibrated the y-theta-phi with Sieve data at 3.57GeV from Marathon run period:
- y_tar at off-center position is slightly improved. Theta-phi seems to have an overall offset;
- the lower order GMp fitting (only 4 terms in theta) can not align the holes very well at the first look. Will check with Longwu how to control the fit.
- Beam Energy
- The measured beam energy (HALLA:p) is plotted versus time. In about 100 runs its value 6 MeV lower than the main distribution. Doug suggested that:
- check the beam energy correction factor (HALLA:dpp) which should not be zero
- we are currently reading the beam energy at the run start (db_run.dat) which could be wrong if the beam was off at that moment.
- Energy Loss
- Rey adapted the energy loss class from GMp to Tritium settings, updated target configurations and materials.
- Trigger-dependent VDC timing calibration
- Shujie checked the impact of VDC t0 offset on tracking:
- Nothing obvious with a 5ns offset.
- For prescaled runs, can use the adapted triggertime class in analyzer to adjust VDC t0 for different trigger type.
- Replay raw data
- Rey setup the code to replay raw data with batch farm and store them in tape library. It takes ~ 5 hrs to replay all e'p runs.
Slides
BlueJeans connection info: https://bluejeans.com/479755873
