How-to
NOTE: If you can't solve the problem in 1 hour you MUST then contact the Run Coordinator! (See also Experts on call)
Contents
How-to's
- The Hall C Operations Manual is a thorough and up-to-date set of instructions.
- Collimator control for HMS/SHMS. Also includes description of the collimators.
- EPICS screens can be found at jmenu -> <search for> "HMS coll" and you'll see both entries
- The usual collimator settings are HMS : "Pion Collimator" and SHMS : "Collimator".
- Hall C Scalers & xscalers instructions for HMS and SHMS.
- SHMS drift chamber instructions
- Hall C DAQ Instructions
- High Voltage Controls
- Quick Replay of raster data ("spot++" equivalent)
- EPICS/Accelerator Screens
- Also includes Stripcharts, Gas System info, Collimator controls, Chamber Thresholds, Harps, etc...
- Hall C BPMs
- Run go_bpms from the cdaq account
- How to see results of Hall C harp scans
- How to bring up the Hall C YAG Viewer camera
- How to bring up the Alarm Handler
- How to bring up the Hall C cameras
- How to restore the Hall C EDTM Pulser
- How to check the HMS/SHMS shutters
- How to perform pedestal runs and determine FADC thresholds
Magnets
- Magnet screen is brought up on any hcdesk machine using
% go_magnets
- For the Fall 2017 run, the SHMS magnets can be set by current from the desired momentum in [GeV]. From any computer, run:
go_magnet_SHMS_current P
where P is the desired momentum in [GeV]. This will return the current that each SHMS magnet should be set to. The formulas and program are in sync with the repository. For precision physics data-taking, the magnets should be put "on loop". Turn off the beam prior to ramping the magnet and putting on loop. The procedure to put the magnet on loop is described here:
Ensure beam is off. 1. Select polarity for electrons or positrons in the magnet gui. 2. Ramp each magnet to the maximum current (see table below for SHMS). 3. Ramp each magnet down to its desired current (the output of go_magnet_SHMS_current).
| SHMS Magnet | Max current [A] |
|---|---|
| HB | 3600 |
| Q1 | 2400 |
| Q2 | 3660 |
| Q3 | 2480 |
| Dipole | 3440 |
If you need to change polarity, first ramp the magnet to 0 [A], and then you can change the polarity. After this change, you will need to ramp the magnet to maximum again.
- For HMS magnets, the current limits are shown in the following table:
| HMS Magnet | Max current [A] |
|---|---|
| Q1 | 1000 |
| Q2 | 600 |
| Q3 | 600 |
| Dipole | 3000 |
Do not exceed these limits! HMS magnets are put "on loop" by going 200 A above the desired set point and then reducing current to desired (see pdf below). The currents for the HMS quads for a desired momentum are obtained by running the field03 program located at FIELD/field03. The HMS dipole momentum has new NMR measurements and can be obtained from the following command:
go_magnet_HMS_current P
where P is the momentum in GeV. This will return the current and the recommended NMR setting.
- Spectrometer Magnets
- How to cycle the HMS quad magnets
- Howard's page of Archiver magnet trend charts
SHMS Detectors
HMS Detectors
Hall C target
Hall C target configuration for Spring 17 running
