[Hps] Daily RC Meeting

[Valery Kubarovsky]

I made a comparison of new 8um and 20 um targets. The rates are almost proportional
to the tagger length. However, the old 8um target and new 8um target rates are different.

We have 8% discrepancy between 2C21A and FC reading now. We did not have such a difference in the past.
FC/2C21A=1.08
There were several log entries about FC offset recently.
Valery


On 8/18/19, 3:09 PM, "Hps on behalf of Nelson, Timothy Knight" <hps-bounces at jlab.org on behalf of tknelson at slac.stanford.edu> wrote:

    Hi Raphael,
    
    I meant to ask today about the differences between the new 8um target and the old 8um target, where the difference is quite large considering that the two foils came from the same sheet.  Do we have any understanding of this?  Are we certain the beam current measurement (mentioned today to be different between the FCup and 2C21) has not shifted in some way?
    
    The reason I ask is that the occupancies with 80nA*20um are higher than 200nA*8um(old) but lower than 200nA*8um(new), so it seems foolish to think we can decide on an operating point (high current*thin target vs. low current*thick target) when we don’t understand this discrepancy. 
    
    Best,
    Tim
    
    > On Aug 17, 2019, at 6:34 PM, Raphael Dupre <dupre at ipno.in2p3.fr> wrote:
    > 
    > Hello everyone,
    > 
    > We are finally back in production since 1PM. Beam is good and steady and we have taken test data sets at various luminosities (see logbook for details). I propose that we meet rapidly tomorrow with those available to discuss our production luminosity and the trigger adjustments to be made in consequence as live time can reduce significantly at the highest settings.
    > 
    > The arrangements remain as usual: in the counting house 2nd floor meeting room and bluejeans for remote participants:
    > 
    > Bluejeans: URL:  https://urldefense.proofpoint.com/v2/url?u=https-3A__bluejeans.com_794825703&d=DwIFaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=ErLkbYGWd8oSAZ70ywHxhA&m=YO8txpxO_ZRED7MUQZsqo1YPlQ_vZESUQ6jaR-_M54g&s=MmHeEB8bYIGfq1Hd2a-zFklj3B6l6X6irtpxd2ZZgMM&e= 
    > Meeting ID: 794825703
    > 
    > Best,
    > 
    > ---
    > Raphaël Dupré
    > Institut de Physique Nucléaire d'Orsay
    > CNRS - IN2P3
    > Université Paris-Saclay
    > 
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