Re: run status.

From: Michael Murray (murray@CyclotronMail.tamu.edu)
Date: Fri Nov 16 2001 - 15:02:22 EST

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       Dear Flemming,
                  would it be possible to take a 
    short run with ZDC voltage dropped by 100V on
    all channels. This would just be to confirm that
    we have no saturation problems.
                Yours Michael
    
    
    Quoting Flemming Videbaek <videbaek@sgs1.hirg.bnl.gov>:
    
    >     The AuAu running is going into the last 10 days of running. With the
    > very succesfull running in the last 24 hours (~940k trigger six in two
    > shifts) the survey program is essential complete and we have stated
    > taken data at 12 deg.
    > 
    > Based on discussion within the collaboration the recomendation (from
    > today's meeting here at BNL), and I trust in agreement with the
    > majority
    > of posted collaboration ideas.
    > (all units in terms of trigger 6)
    > 
    > a) Continue high statistics running at 12 deg until end of run 
    >     - 1M A,B with 1/2 field (.9M A done) 
    >     - short 0-field run
    >     - 4-8M at 2/3 field 
    > 
    > b) complete some MRS 90 deg low field
    >    - collect ~1.5M at 40 deg for possible HBT (and understanding of
    > this)
    >    - collect at 90 deg with 6B for remainder of run ~3-7 M. (with give
    > upto 20-30 protons per 200 MeV/c at 3-4 GeV/c)
    > 
    > The plan as well as accomplishments since ~10/15 can be found on the web
    > summary
    > http://pii3.brahms.bnl.gov/~operator/shifts/RunStatistics2001.htm
    > 
    > A few works on feasibility and expectations.
    > 
    > - based on a rapid analysis of run 5812 (only) with ffs tracking (good
    > status, good swin, tight Ty) we get about 1 count/100K trigger 6 per
    > 200MeV/c ptbin at 3 GeV/c (at 15 GeV/c just above the P.ref.) an
    > extrapolation to 4 GeV/c being outside the favourable acceptance might
    > give 0.02-.03 in the same pt-width.
    > 
    > Thus the expected rate may be in order 10 per 1M at 3 Gev/c and .3 at 4
    > GeV/c with a maximum of 100, and 3 in the remainder of the run.
    > This the needs effeciency factors for Back FFS (a good fraction of the
    > tracks in the optimum p range will go through the full spec though
    > not all . To optimize acceptance for pt~ 2-4 give the recommended value
    > of 2/3 in field setting. As you can see to get any reasonable
    > statistics
    > one has to stick with essentially one setting.
    > 
    > 
    > This is also a last call for 'missing' settings i.e. short <=200K of
    > previously taken one, 
    > that for one or another reason has problems.
    > 
    > regards
    >     Flemming
    > 
    > 
    > 
    > ------------------------------------------------------
    > Flemming Videbaek
    > Physics Department
    > Brookhaven National Laboratory
    > 
    > tlf: 631-344-4106
    > fax 631-344-1334
    > e-mail: videbaek@bnl.gov
    > ------------------------------------------------------
    > Flemming Videbaek
    > Physics Department
    > Brookhaven National Laboratory
    > 
    > tlf: 631-344-4106
    > fax 631-344-1334
    > e-mail: videbaek@bnl.gov
    > 
    
    
    
    Michael Murray, Cyclotron TAMU, 979 845 1411 x 273, Fax 1899
    



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