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    User name J. Zhang

    Log entry time 17:25:11 on September 27, 2010

    Entry number 332957

    This entry is a followup to: 332162

    keyword=FADC DAQ test after formware updrade

    Ahmed and I did a pulse test to the FADC after Hai Dong upgraded the firware. This upgrate is supposed to solve the accidental coincident rate problem which we met during PREX commissioning.

    The purpose of this test is to find out A) if the firmware upgrade successful? B) Does FADC and its software works fine with 1000 Hz MPS frequency? C) TakeLED and Cosmic run to verify the spectrometers ready to work for DVCS. Here is the brief summary.

    1) FADC run number 2124 - 2158 are run with 120 Hz helicity frequency 2) FADC run number 2159 - 2158 are for 1000Hz helicity For details about the FADC configuration please check http://www.jlab.org/~moller/jixie/log/run-list_moller_23Sep2010.txt or adaq@hamoller:/adaqfs/home/adaq/moller/run-list_moller_23Sep2010.txt

    3) In order to see coincident between Scintillators and Calorimeters, I have to delayed Calorimeters pulse signal by 16ns with cable 4) The variable "FADC_DELAY_CRL" in fadc_params.cnf means the number of delayed time samples of CR to CL, which means CR signal have to be later than CL signal. In this test, I delayed the left arm 48ns, I could not find any accidental coincident. Then I delayed the right arm signal by 48ns and found the accidental coincident between the left and the right arms. 5) The firmware upgrade is successful 6) The FADC DAQ works fine with 1000Hz MPS rates, and the software can analyze 1000Hz data 7) Cosmic and LED run have also been taken, the results shows that the spectrometer is also in working condition.

    -- Best Regards, Jixie Zhang Jefferson Lab - Hall A - A112, 757-269-5352 _______________________________________________

    A copy of this log entry has been emailed to: Brad Sawatzky" <brads@jlab.org>, "Zafar Ahmed" <zahmed@jlab.org>, "Oleksandr Glamazdin" <glamazdi@jlab.org>, "Pomatsalyuk Roman" <romanip@jlab.org>, "Eugene Chudakov" <gen@jlab.org>, <bob@jlab.org>, jixie@jlab.org