[PEPPo] PEPPo beam test on Tuesday

[Eric Voutier]

    Hello All & Alex,

    If integrated mode is not operational, there is no real reason to 
put the beam in the polarimeter for the
    measurements. In fact, event a 30 pA CW beam at 6 MeV is expected to 
give you 1 MHz counting rate,
    meaning to much pile-up to make sens of the semi-integrated or 
sample method.

    I suggest that you send the beam in the spectrometer dump with 
closed -jaws, and you run ALL crystals
    to try to measure an asymmetry connected to the background in 
semi-integrated mode. I put an ATLIS
    in that sens about a week ago "PEPPo shielding quality assesment". 
The idea is to be as close as possible
    to real experimental conditions in terms of counting rates, and take 
the data for different configurations of
    bend angle of the beam, with and without production target, but 
making sure that the background we measure
    is coming from this area (therefore the closed jaws).

    This would be a very valuable measurement checking all the TI's and 
adding info to progress on PEPPo
    operation. Even only 4 different setting would help to understand 
things.

    - Make sure to apply LV in the service building, by default I 
disconnected it.
    - Check MJL (I in principle reshaped it for 100ns wide, before we 
understand what Tony observed) and make
      sure FADC trigger is L1A.

      Have fun, Eric


Le 02/04/2012 11:49, Alexandre Camsonne a écrit :
>
> I have a bit of problem adapting mode 3 to the usual event structure 
> most likely still some typos in read out code but maybe an 
> interference between boards too, so i think i mostly want to take data 
> in sample with new and old TI, this should work transparently in 
> decoder, to have a first glimpse at background and asymmetries. If we 
> have i could take a short run in mode 3 with the readout which is working.
>
> So in 60 minutes,
> we could try tune beam in Compton 15 20 minutes
>
> power one peripherical crystal
>
> take amplified data sample old ti 5min
> take amplified data new TI 5 mins
> take amplified data new TI buffered 5 mins
>
> We should see an asymmetry.
>
> We could take a run in mode 3 if time allows but i still need to make 
> sure and set pedestals right so that might wait fir next week.
>
> Alexandre
>
> On Apr 2, 2012 11:31 AM, <fanchini at jlab.org 
> <mailto:fanchini at jlab.org>> wrote:
>
>
>     IOf Riad and alex are working to compute charge asymmetry with
>     BCM0L02,
>     this should be ok. They already have the stuff to use. If they
>     want to use
>     mode 3 (new fadc) i can say not. I did not finish and here i
>     couldn't work
>     on it.
>     E.
>
>
>     > This is just a reminder that we're planning to execute our first
>     CW beam
>     > test tomorrow planned to begin ~noon:
>     > http://opsweb.acc.jlab.org/CSUEApps/atlis/task/12270*
>     >
>     > Alexandre/Riad* - What is the status of the DAQ, as I know a
>     bunch of
>     > work was planned since last Thursday?
>     > *
>     > **Eric/Erica* - We know you won't be here and received your advice
>     > below.  Have you closed the loop w/ Alexandre or Riad for the exact
>     > measurements you'd like to have made. _Assume <60 minutes total test
>     > time_.
>     > *
>     > Leke/Paul* - Will one of you be around in the afternoon to test
>     if your
>     > repair last week solved the fiber array signal problem. _Assume
>     <30 min
>     > total test time._
>     >
>     > *Tony *- If time permits do you want us to make a measurement w/
>     cw beam
>     > on target viewer (50-1000pA); if yes, please spell out the
>     conditions
>     > you'd want. _Assume <30 minutes total test time_.
>     >
>     >
>     >
>     >
>     >
>     >
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>
>
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