re T3 and current running

From: Flemming Videbaek (videbaek@sgs1.hirg.bnl.goV)
Date: Fri Oct 05 2001 - 06:28:44 EDT

  • Next message: Ian Bearden: "RE: 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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