Beam Line

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Revision as of 18:19, 26 October 2008 by Jiang (Talk | contribs) (Beam position monitors (BPM) and calibration procedure)

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E06-010 Instrumentation Requirement List: Jian-Ping Chen's memo to Kees De Jager, 08/07/08

.doc file and htm file

File of Physics/MCC experiment planner, by MCC Lester Richardson 10/21/2008

doc file page-1 and pdf file page-1, doc file page-2 and pdf file page-2

ARC energy measurement

Compton Polarimeter

HARP and HARP scan procedures

Please follow the directions at the Harp Scan Page [Harp Scan page]

Beam raster

Beam charge monitors (BCM) and calibration procedure

Beam position monitors (BPM) and calibration procedure

How to perform a BPM pedestal run:

1. MCC has to follow the following procedure:

    - open BPM window "BPM Diagnostics - SEE"
    - from there pull down the "Expert Screens" and open "Gain Control"
    - for IOCSE10, use the pull down window and change from "auto gain" to "forced gain". 
    - then change the forced gain values x and y to zero.

2. CODA has to run in pedestal mode:

    - if you were running before you first have to press Abort
    - choose the appropriate configuration in runcontrol
    - select "PEDRUN"  - Press RunTypes button in RunControl, download.
    - raster off. take a run, we don't need beam for this activity.

3. Have MCC change the BPM gain back to "auto gain".

4. Run get_bpm_pedestals.C in the root analyzer: Updated on October 26, 2008!

    - this code is now available from the onlana account on the adaq machines
    - run analyzer and type:
          get_bpm_pedestals(<runnumber>,<number of events>) with the run number and number of events you want to replay. 
    - the code should print out the new pedestals at the end 
    - post the plots and results in the Halog
    - an expert  should load the database into an editor and change them (2nd line of the [BPMx] blocks)

How to perform a bulls eye scan:

1. You need unrastered beam:

    - caution you should not do this with a target requiring rastered beam
    - use carbon, BeO, optics, or in the worst case empty instead

2. Ask MCC to steer the beam to the nominal center of the target.

3. Wait until beam is stable and have MCC perform a harp scan for 1H03A and 1H03B and a coda run during the same time.

4. Ask MCC then to steer the beam to positions around the nominal center:

    - cover at least the area the raster will cover: (2,2), (2,-2), (-2,-2), (-2,2) and repeat (0,0)
    - repeat harp and coda runs for each position

5. Record Harp scan run numbers and corresponding CODA run number for each beam position.

6. Make a record of the harp scans and CODA runs in the Halog.

How to analyze the bulls eye scan:

 - detailed instructions can be found at the Analyzing BPMs website.
 - the shift crew is not expected to analysis the bulls eye scan.

Moller polarimeter and results of measurements

Scattering chamber upstream and downstream beam pipe size and window thickness

HAPPEX Luminosity (Lumi) monitors

Beam dump