[Halld-cal] Added angular plots for pi0s

[Will Brooks]

Dear Elton,

  Very nice plots!

  One might argue that if no photons go at large angles for 
calibrations, they won´t go there either for the measurements you´re 
interested in. But in the interests of calibrating the detector as well 
as possible, it might be interesting to explore different approaches, 
such as using a lower beam energy. Do we know how low the beam energy 
could go? Also, one could run untagged and just make a very large number 
of pi-0's, so the back angles would be more populated, but there may be 
other issues in that case, e.g., tagger beam dump current limit, 
radiation dose limits, etc.

Thanks,

  - Will



On 2/10/11 8:04 PM, Elton Smith wrote:
> Dear collaborators,
>
> Will suggested I look at plots of the angular distribution of pi0s, as
> it likely varies considerably over the length of the bcal. I added two
> plots of the angular distributions to GlueX-doc-1702, for two different
> photon energy thresholds (0.2 and 0.5 GeV). As expected, the
> distributions are quite steep. It is likely that the calibrations will
> be limited for angles beyond about 50 degrees. Of course this can be
> looked at more quantitatively.
>
> Cheers, Elton.
>