Sorry ALL! I though I sent this last night but I just checked my email now
and saw that it was returned to me (incorrect address) so here is last
night's summary:
Cerenkov Gain Matching:
The plan for the evening was to support the wire chamber group and to
begin gain matching the Cerenkovs. The gain matching procedure is as
follows:
Set all of the Cerenkov tube voltages to zero except for one tube in each
box which will be nominally set to -2000V.
Take flasher data as this will provide uniform event for all tubes of one
box.
Adjust the tube voltage for the desired adc target channel and then repeat
this for one tube at a time per box until all tubes of a single box yield
the same adc peak.
Effectively we will be able to only gain match tubes to each other
in a single Cerenkov box as the flasher signal is not constant from box
to box.
Eventually we will hopefully match all boxes by moving all tubes of a
certain box by the same percentage.
The wire chamber group was using trigger elastic_tof_10-15.
I added a line for the left sector 00xxxx1111111111 to accept flasher
data. I had to put x's for the Cerenkovs or there were no triggers. This
may be due to the single tube signal not being high enough to pass the LE
discriminator.
The macro created to look at flasher data is called
CerenkovGAIN.C and is in my directory:
/home/blast/karpiusp/recon/blast/run
This macro reads a .root file which contains the ntuple created by
ntuple.C so that must be run first to use it. It just plots ADC and TDC
data for the Cerenkovs but it cuts on multiple simultaneous TOFs to filter
out the flasher data.
Runs 1831 and 1832 were taken but there were no distinguishable flasher
peaks in the adc spectra. This was double checked by running plot_adc.C.
The flasher did indeed appear on the scalers from the photodiode and the
flasher/detector trigger. Upon checking the raw signals with the scope a
clear flasher signal was seen for the raw Cerenkov signal going into the
linear adder. But, the signal out of the adder, which goes to the
trigger/adcs/tdcs showed no sign of the flasher although I did see signal
from cosmics/beam!
Near end of shift trying a work around plan to see if we can see flasher
at all in adc. Plugged LCerenkov PMT 1 into LTOF12 top just to get it to
and adc. Have yet to analyze this run. Have given Tavi the low down and
he is ready to go!
Pete
-------------------------------
Pete Karpius
Graduate Research Assistant
Nuclear Physics Group
University of New Hampshire
phone: (603)862-1220
FAX: (603)862-2998
email: karpiusp@einstein.unh.edu
http://pubpages.unh.edu/~pkarpius/homepage.htm
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