[Halld-tagger] Microscope coverage

[Alexander Somov]

Hello Richard, all,

I think that extending the microscope slightly above
9.1 GeV could be 'convenient' from the  fine-tuning
of the goniometer point of view, i.e., if we use the
microscope only for this fine-tuning. The peak is sharp
though it's close to the border.  Anyway, I agree, the
low-energy region seems to be more important.

Cheers,
        Alex



On Fri, 19 Oct 2012, Richard Jones wrote:

> Alex and all,
>
> The microscope should extend some distance above the coherent edge so as to 
> have as continuous as possible a measurement the peak region, for the sake of 
> systematics in the CBSA extraction of polarization.  However the fixed array 
> can easily provide 100% coverage above 9 GeV, whereas there are rate problems 
> trying to do the same thing with fixed array counters on the low side of the 
> peak.   In light of this, here are some trial concepts to consider.
>
> 1. 100 energy bins in the microscope: 8.15 - 9.10 GeV
> 2. 120 energy bins in the microscope: 7.96 - 9.10 GeV
> 3. 150 energy bins in the microscope: 7.68 - 9.10 GeV
>
> -Richard Jones
>
>
> On 10/18/2012 6:18 PM, Alexander Somov wrote:
>> Hi,
>> 
>> One thing we have to discuss regarding the final
>> microscope location. We've already started discussing
>> this long time ago.
>> 
>> To cover the photon energy range between 8.3 GeV and
>> 9.1 GeV we will need about 78 columns of microscope
>> counters. The energy range per counter is ~ 10 MeV.
>> 
>> The microscope consists of 100 columns so that it should
>> cover about 200 MeV larger range. I think that we should
>> 'distribute'  this 200 MeV equaly for both low- and
>> high- energies, i.e., to cover the range
>> 8.2 GeV < E_gamma <  9.2 GeV.
>> 
>> Any suggestions ?
>> 
>> 
>> Thanks,
>>          Alex
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>
>