Beam startup/recovery Procedure

Procedure for major beam down: more than 2 hours or so

• Initial requirements:
1. Beam energy lock: ON Hall A
2. Fast feedback lock: ON
3. Target: Empty target
4. Raster: OFF
5. VDC: OFF
• Setup beam to Hall:
1. Let MCC tune beam through Compton chicane with 2 μA beam.
2. Make sure BPM A and B readings are within accepted range (see whiteboard).
• Harp Scan:
1. Ask MCC to do a harp scan, make sure beam σ_x,y within 100 - 300 μm on both hall A harps.
       (these harps are called IHA1H03A and IHA1H03B, or H03A and H03B for short)
• Beam position check with BeO target:
1. Move target to BeO, ask for 5μA beam with raster off.
2. Make sure the beam spot on the camera matching the marker.
3. Ask for 4x4 (MCC unit) raster and 10 μA beam , take L-HRS data with T1 trigger only. Check monitor and do spot++ to verify the raster size: 2.5x2.5 mm².
• Clearance check on LD2 target:
1. Turn ON VDC high voltage, let the HV ramp up and do next steps.
2. Move to LD2 target, keep 4x4 (MCC units) raster and 2 μA beam.
3. Check rate with reference number posted on the right side of the scaler monitor.
4. Take L-HRS T1 data and check raster size with spot++: 2.5x2.5 mm². Make sure no sign of cell wall hitting.
5. Ask for 6x6 (MCC unit) raster and make sure rates stay the same.
6. Make sure that the VDC high voltage is set.
7. Take 200k (also see #8 below) T1 data on BOTH HRS with pre-scale factors so that the recorded rates are about 2 kHz. Do spot++ to check raster size, 4x4 mm² (6x6 MCC unit), and make sure no scraping on cell walls. Record the run number. This will be used as Q2 measurements or for PID analysis.
8. If this is the first time you run at a new kinematics, take 500k T1 data on BOTH HRS, then analyze the run and post the Q2 and W plots in halog.
• Now beam is good to go:
1. Turn OFF VDC high voltage for production or any high rate tests (T1>10 kHz).
2. Ramp current slowly, keep an eye on the LD2 target temperature.
3. Start to take data and have fun.

Procedure for short beam down: less than 2 hours and no beam parameter change

• Same initial requirements as long procedure.
• Setup beam with 2 μA on Empty target.
• Clearance check on LD2 target:
1. Move to LD2 target, ask for 2μA beam and 6x6 (MCC unit) raster. Verify rates.
2. Taka a short run. Do spot++ to check raster size, 4x4 mm², and no touching of cell walls.
3. If this is the first time you run at a new kinematics, turn ON VDC and take 500k T1 data on BOTH HRS with pre-scale factors so that the recorded rates are about 2 kHz, then analyze the run and post the Q2 and W plots in halog. Record the run number. This will be used as Q2 measurements or for PID analysis.
4. If you turned ON the VDC in step 3, turn it OFF now.
• Now beam is good to go. Make sure VDC is OFF and you can start production.