[Hps] HPS is taking data

[burkert]

Hi all,
  Congratulations to starting the real data taking!

I have a question on the single cluster energy spectrum. I would expect 
that single clusters at forward angles should have a peak at nearly the 
full beam energy from quasi-elastic ep scattering minus the platinum 
binding energy, and at very-very forward angles from e-PT -> e-PT 
elastic scattering. The peak sits however at much lower energy , which 
may indicate incorrect energy calibration, or the energy in the cluster 
is not completely summed up.
My question is, how many crystals are summed up to define an energy 
"cluster"?

Volker



On 12/13/14, 11:05 AM, Maurik Holtrop wrote:
> Hello Takashi, Stepan and all of you on shift,
>
> This is really great!
>
> I went through the logbook entries and don't see the entry that explains what the source of background was and how it was eliminated. If you have a moment, could you please point me to the right entry? Was it beam-gas interactions?
>
> Best,
> 	Maurik
>
>
> On Dec 12, 2014, at 8:39 PM, Maruyama, Takashi <tvm at slac.stanford.edu> wrote:
>
>> With heroic effort by Stepan, the anomalous source of background was identified and eliminated completely. 1.5 micron-thick Pt target was inserted. Attached is a ECal single rate map at 10 nA. This is very similar to what you see in Monte Carlo.
>>
>> Ben has setup a very loose two cluster trigger and Sergey's DAQ system is taking data at 4.5 kHz at 10 nA. This data will be used to find optimum cuts for pair trigger.
>>
>> Takashi
>> RC <fadc_firsttarget.png>_______________________________________________
>> Hps mailing list
>> Hps at jlab.org
>> https://mailman.jlab.org/mailman/listinfo/hps
>
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