RHIC CNI Polarimeter Operation Instructions

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Polarimeter Targets

Tank

Blue 1

Blue 2

Yellow 1

Yellow 2

Default

H1

V1

H2

V1

Backup

H3

V3

H4

V3


Note:
A. Take AGS polarization measurement with intended fill intensity before filling RHIC.
B. Take injection measurement with B1V, B2H and Y1V targets, unless the Y2H target is broken and a new target is needed. Then the new target has to be used(conditioned) at injection..
C. At store, take blue and yellow polarization measurements alternatively. The second one can start as soon as the first one status read "reading Data". This is to save time.

0. If even target is used, use park mode (from setup, select park mode) for that polarimeter. Others can use regular mode for now. Right now, none is needed with park mode.
1.For physics store preparation: at injection, take polarization measurements before ramp with one polarimeter (Blue with horizontal target, yellow with vertical target).
2.. Take polarization measurement with all polarimeters after energy ramp, then at 3 hours, 6 hours and at the end of the store. Remember to ramp down Landau cavity for store measurements.
4. 20 million events are good enough for store at this point. At store, you are allowed to change the speed (to get enough but not too many events) and range of target sweep (to reduce measuring time).
5. Please watch four videos on Ad4b display while taking polarization measurement. If something worth of writing, put it into elog.
6. Important: if a target is lost in the middle of store, don't switch to next target. Wait till injection to switch to the new target. This way, the target get "conditioned". (updated 5/8/2013)

Procedure

A.     Injection

1.      Target scan

  If target scan is needed ( we don't need it for normal operation), use 1 bunch only for target scans.

  Scan Blue & Yellow.

        You get an emittance measurement for free.

2.      Polarization Measurements

  Measure polarization in sweep mode with same beam you are going to ramp. The measurement can start as soon as one ring is filled.

  When RHIC is ready for ramp, fill Blue & Yellow with desired bunches.

  Events between 20-30 million are good enough. The speed should not be slower than 100 and not faster than 5000. Note: you can only change number of events by velocity in this mode. Increase sweep velocity(in step of a few hundreds) if events are high and decrease sweep velocity if events are low.

 

  Check Analysis Summary. Dump analysis and measurement pages to elog.

B.     Beginning of store

1.      Polarization Measurements (waiting for low beam decay or successful collimation)

  Events between 30-40 million are good enough. The first measurement should be done before putting beam into collision. Note: you can only change number of events by velocity in this mode. Increase sweep velocity(in step of a few hundreds) if events are high and decrease sweep velocity if events are low.

  Blue & Yellow, profile-by-sweep mode with both polarimeter2(first) and polarimeter1(second).

  Check Analysis Summary. Dump analysis and measurement pages to elog.

C.     During store

1.      Polarization Measurements every 4 hours and at the end of store.

  Events between 30-40 million are usually good enough. The actual goal is to get error bar of 2.5% and not too much smaller than that. Please adjust velocity to achieve that. You may need to increase the velocity during the store to maintain the similar error bars. Note: you can only change number of events by velocity in this mode. Increase sweep velocity (in step of a few hundreds) if events are high and decrease sweep velocity if events are low.

D.     Emittance Measurement

1.      Operators use only the default targets to do emittance measurements when asked. Dump the pictures into elog.

2.      If the so-called "emittance calibration run" is required, call emittance fan Anatoli.

E.     Target Switch

1.      When a target is lost (indication would be no or very few events + no beam decay increase when target inserted), operators can switch to the backup target defined in the following table. This means that you are only needed (allowed) to switch target on the same axis (e.g. H1 to H2). For target operation beyond that, consult experts.

2.      To switch target, go to "TargetScan"tab. Make sure the default axis (horizontal or vertical) is selected. Select the desired target number. Proceed from there.

 

 

 

General rules

0. One can not run polarimeters in the same ring (Blue2 and Blue1 or Yellow1 and Yellow2) the same time.

1. Target scan should be done with one bunch at injection. Do not do target scan at store.
2. Take profile by sweep measurement every three hours in store with 60 million events as limit. Events between 30-40 million are good enough. Increase sweep velocity if events are high and decrease sweep velocity if events are low.
3. The control of target, measurements are similar to last run. Details will be found in
Operation wiki.
4. There is another wiki page maintained by polarimeter groupPolarimeter Group wiki.  

 

How-to Instruction (take blue as example):
From StartUp->RHIC->PolarControl(Blue)
Select TargetScans tab. Select direction tab (horizontal or vertical). Default is blue2 with horizontal, blue1 with vertical.
Select Target. Default orientation tab is highlighted..
Take target scan by click start. There may be a warning popup shown after the target scan. Click OK.
Select Polarization Measurements tab. Select Measurement type. For the ramp development period, Fixed target for injection and Profile by sweep for store. Click Data Run.

Call List
Overall operation: Grant Webb, Anatoli Zelenski, Bill Schmidke, Haixin Huang.
Application: Seth Nemesure, Jim Jamilkowski, Al Marusic
Polarimeter pc: Grant Webb

Troubleshooting Guide.