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    User name mcnulty

    Log entry time 09:28:57 on August25,2009

    Entry number 285837

    keyword=Prex test runlist

    Prex test runlist: Starting 8/25 at 01:45
    Data for 5uA on thin Ta
    4303 ps2=1, ps3=1 (s0=1.4kHz, Scint=400Hz) Dipole settling to 1.206
    4304 mostly beam tuning
    4305 ps2=1,ps3=1 (quartz= about 1Hz for 1.206 (+0.7% dp/p))
    4306 ps2=50,ps3=1 (quartz=10Hz for 1.202 (+0.4% dp/p))
    4307 ps2=50,ps3=1 (quartz=1Hz for +0.7% dp/p)
    4308 ps2=50, ps3=1 (quartz=10Hz for 1.198 (+0.1% dp/p))
    4309 ", ", (quartz=25Hz for 1.194 (-0.2%) Dipole changing a bit here

    Made Access (02:45-04:15) to check quartz signal cabling and replace 45deg quartz detector with 0deg 1cm thick quartz, checked ADC gate timing of quartz signal--to do this we needed to use a quartz detector self trigger--the timing was good. We reestablished the prex_scint trigger (T3). Also moved prex test dets 11mm away from beamline in y direction--for better y alignment.

    4310 - 4313 Cosmic/DAQ tests
    4314 ps2=50,ps1=1, (s0=1.5kHz,Scint=600Hz) Dipole is scanning here
    4315 ps2=10,ps3=1 more dipole scanning

    Note that after a preliminary analysis of these runs, the quartz signal is still difficult to distinguish from pedestal.

    Made Access (0600-06:30) to change the T3 trigger from Scint to Quartz (note that now the quartz signal is R.cer.a[2] and the Scint signal is R.cer.a[3]).

    Note that for all the above runs, the T3 threshold is 30mV

    We are now taking 5uA on thick Ta using (-0.2% dp/p).
    4316 threshold = 60, ps2=10 or 50?, ps3=1 (s0 rate is 10k)
    4317 thresh=100, ps2=1,ps3=1 (T3 rate is ~250Hz)
    4318 thresh=100, ps2=1,ps3=1
    4319 thresh=100, ps2=50,ps3=1
    4320 thresh=30, ps2=1, ps3=1

    Many of these runs have been analyzed. The root files can be found here:

    Pcture 1 shows a very raw pulse height distribution from the Quartz (self triggered). More analysis is needed to understand this distribution, but at least it is something besides a pedestal.

    FIGURE 1