[PEPPo] Daily Report 21 June 2012

[Arne Freyberger]

Wednesday June 20th, production running at 3.2MeV/c on the 1mm W target 
was completed.   This completes (for the second time) the 1mm W dataset.

With the 1mm W dataset, complete.  Discriminator and beam current scans 
were performed for all momentum before switching to the 0.1mm W target.

Conditions for the 0.1mm W target are a bit different than the 1mm W 
target.  Production beam current is about 380nA.  PMT5 rates are higher 
at about 4kHz.   Coincidence trigger rate is about 140Hz.   Additionally 
the discriminator threshold on PMT5 was increased to reduce the 
accidentals.   The signal to noise is not as good with the 0.1mm as it 
is with the 1mm target.

Swing and Owl completed 7 datasets, corresponding to about 3.5M triggers.

At 140Hz it will take 8 shifts to get 32M events, and this does not 
account for the reduced signal to noise.   Clearly this will impact the 
end game plan which continues to evolve.

For Swing/Owl tonight we will continue with production 0.1mm, 3.2MeV/c 
data collection.

Cheers,
Arne

-- 
Arne Freyberger
Director of Accelerator Operations
Jefferson Lab           Office: (757) 269-6268
12000 Jefferson Avenue  Cell:   (757) 876-6289
Newport News, VA 23606  Email:  freyberg at jlab.org