[PEPPo] Daily RC Report 5/29

[Joe Grames]

*Daily RC Report 5/29:*
Efforts over the last shifts have focused on the collection process and 
detector setup to measure and distinguish both e- and e+.  Last SWING 
began with Ebeam~6MeV/c and extended e- collection to ~first systematic 
effort to collect e+ and provide a signal for detector setup.  A first 
pass collect of e+ at 4MeV/c was performed and the spectra is perhaps 
first indication of the positron signal exiting the vacuum window.  
However at the end of SWING the E1 detector was removed to facilitate 
setup of the Compton detector (PMT5) in coincidence w/ TS1.  Because the 
efficiency of Compton rate to positron rate is ~1E-3 the initial setup 
in e+ mode was later switched to degraded e- in order to help determine 
the TS1/PMT5 coincidence.  On last DAY we performed fiber array detector 
checkout with beam; there was some signal in vertical array, but 
detector is not ready to be used yet.  Afterward, we increased the beam 
energy to ~8MeV/c production and characterized collection of e- and e+ 
using T1=0.1mm W and beam currents up to 5 microAmps.  The target 
performed fine and vacuum level remained below ~5E-8 Torr.  At the 
beginning of SWING tests to repeat characterization w/ T1=1.0mm W were 
in process.  The goal is to learn that we can systematically recover 
yields of e- or e+ using similar conditions of target, beam current and 
magnet settings, such that detector commissioning and calibration may 
proceed.

*Noteworthy items:*
1. I will prepare a brief RC report for the Wed 8am meeting, also when 
Eric takes over as RC
2. Spectrometer PS occasionally trips off on HV fault during polarity 
reversal; must go to ISB to reset PS
3. The annihilation detector (right) is again working and installed.

*Next 24 hours:*

Tuesday, 5/29 - SWING SL=Freyberger

    Using P=8MeV/c repeat collection study of degraded e- and e+ from
    T1=1mm W
    Setup e- or e+ conditions for OWL optimization of coincidence
    between TS1 & PMT5

Wednesday, 5/30 - OWL SL=Suleiman

    Optimization of conincidence between TS1 & PMT5 w/ e- and e+

Wednesday, 5/30 - DAY, SL=Grames

    Further optimize e- and e+ collection vs. collimator settings
    Use steering magnet and PMT's to deflect e- and e+

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