[PEPPo] Daily RC Report 6/4

[voutier at lpsc.in2p3.fr]

https://positron.jlab.org/wiki/index.php?title=Mon%2C_June_4%2C_2012_(Voutier)

'''Daily RC Report'''


''Moving to positron running !''


'''Data Taking'''

The data points at 3.2 MeV/c and 7.2 MeV/c have been measured over the  
previous swing and owl shifts. The electron calibration has been  
completed with good quality data. The on-line analysis is summarized  
in the PEPPo log entries

http://opsweb.acc.jlab.org/CSUEApps/elog/entry/1789921
http://opsweb.acc.jlab.org/CSUEApps/elog/entry/1790003

Note that there was a confusion between momentum and kinetic energy  
which affects the extrapolation of the simulated data from
Lekke's tables. Note also that simulations are considering an ideal  
ponctual electron source at the location of T2. This may be part of  
the disagreement between data and simulations, particularly for the  
surrounding crystal, but the general trend as function of energy is  
reproduced and there is a global agreement with E166 results for all  
the crystals.

Investigation of the data is progressing and a preliminary comparison  
between Mott and Compton data during the measurement of the  
polarization orientation sensitivity is available.

http://opsweb.acc.jlab.org/CSUEApps/elog/entry/1790083

'''Beam'''

The polarization was optimized at the Mott polarimeter to be as much  
as possible longitudinal. A complete Mott measurement
will happen after the 2 first positron data points.

'''Hardware'''

The power supply issues were troubleshoot over the morning. Two issues  
have been isolated: the slow drift of the current, and
the glitch at a regular frequency. The drift is within the  
specifications of the power supply and the beam expert on shift will  
have to watch the dipole current and keep it stable by looking at the  
transducer value. The glitch does not seem to be connected to the  
power supply but to the read-out of the current on the transducer; it  
appears on all PEPPo magnet power supplies.

'''Event'''

The injector was down for 4h due to bad temperature regulation on the  
capture cavity.

Next 24 hours:
Monday, 6/4 - SWING SL=Alexandre CAMSONNE
    Setting up to the highest achievable beam energy
    Optimizing positron collection at 4.2 MeV/c
    Optimizing DAQ setup

Tuesday, 6/5 - OWL SL=Jean-Sebastien REAL

    Positron data taking at 4.2 MeV/c

Tuesday, 6/5 - DAY, SL=Joe GRAMES

    Positron data taking at 4.2 MeV/c


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