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    User name jroche

    Log entry time 11:58:26 on February 25, 2011

    Entry number 348577

    This entry is a followup to: 346891

    keyword=(late entry DVCS) better BCM calibration from December 23, 2010

    In my previous entry, I reported the results of the December 23, 2010 BCM calibration. At that time I stated that I had been unable to find data for the faraday cup in the injector so that the calibration had been performed against the OLO2 readings assuming that the calibration between the OLO2 and the Faraday cup had not changed since the last time we had data in both devices at the same time (November 24, 2011). Since someone pointed to me that I could retrieve the data for the Faraday cup in the Epics Tree. So I did. On December 23, the readings of the Faraday cup and the OLO2 BCM differed by 1% (as they did on November 24, with OLO2 reading higher).

    Taking this into account, the results from the new analysis are:

    i=0 title=U1  coeff=0.2755+/-0.0004 const=-0.192+/-0.005 
    i=1 title=U3  coeff=0.0893+/-0.0001 const=-0.053+/-0.003
    i=2 title=U10 coeff=0.0585+/-0.0001 const=-0.009+/-0.001
    i=3 title=D1  coeff=0.2446+/-0.0004 const=-0.095+/-0.004
    i=4 title=D3  coeff=0.0787+/-0.0001 const=-0.020+/-0.003
    i=5 title=D10 coeff=0.0249+/-0.0000 const=-0.001+/-0.001
    
    U1    tcl process constant=  3717 offset=   714
    U3    tcl process constant= 11468 offset=   612
    U10  tcl process constant= 17491 offset=   157
    D1    tcl process constant=  4187 offset=   398
    D3    tcl process constant= 13006 offset=   258
    D10  tcl process constant= 41105 offset=    61
    

    The calibration of the scaler is done against the 1024 Hz clock.