RE: re T3 and current running

From: Ian Bearden (bearden@nbi.dk)
Date: Fri Oct 05 2001 - 07:45:21 EDT

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    The analysis of the 'scan runs' would be underway, but the connection to BNL
    from NBI is even worse than usual.
    Also, it does not seem to be possible to use BRAT on the crs farm.  I
    suppose this is related to the AFS problems of the past few days.  RCF
    claims that things are working, but I cannot connect to any RCF machine to
    find out.
    Since this is not an unusual occurrence, we should perhaps try to find a way
    to be more independent of the RCF and BNL computers.  How we do this in
    practice, I have no idea today (at least not within present financial
    constraints).
    Ian
      -----Original Message-----
      From: owner-brahms-l@bnl.gov [mailto:owner-brahms-l@bnl.gov]On Behalf Of
    Flemming Videbaek
      Sent: Friday, October 05, 2001 12:29 PM
      To: brahms-l@bnl.gov
      Subject: re T3 and current running
    
    
      Regarding - T3 problem. Without more details it is hard to draw
    conclusions from remote (where I am too).
      -Clearly from 'normal' events we have seen from 10-30 hits/plane * 30 ~
    900, well below
      the limit.
      - It is likely related to events with a very large  number hits either
    event related or from the general background that
      are causing the general large currents in the DC (T5 in particular) and
    high singles rates in H2. And as Ian
      points out T3 can now 'see' quite far down along the beam towards 12
    o'clock.
      - It is unlikely the threshold was touched- the scan plan was very
    specific, as also summarized in the report.
    
      Since this it not known to all - the main reason for the scans is provide
    a better understanding for the operation
      of the drift chambers, which has a much lower effeciency per chamber for
    overall track finding than is desireable.
      When the scan runs are analyzed (probably already underway) we should get
    a report. It may well be needed to
      perform some more of these in the next couple of days.Until better
    understanding of the DC operations emerged
      we should return to angle and magnet settings where the physics
    measurements can be carried out primarely with
      the Front Forward spectrometer, and not the high momentum settings, that
    requires DC tracking.
    
      regards
    
      ------------------------------------------------------
      Flemming Videbaek
      Physics Department
      Brookhaven National Laboratory
    
      tlf: 631-344-4106
      fax 631-344-1334
      e-mail: videbaek@bnl.gov
    



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