[Halld-cal] gluing BCAL light guides

[Eugene Chudakov]

Hi Zisis,

On Fri, 2 Jul 2010, Zisis Papandreou wrote:

> light guides.  They measured the optical cross talk that resulted from
> this and it was only a few percent, so it did not hurt reconstruction
> and it may have even helped by "smoothing" out the cluster distribution.

as far as I understand it, the light leakage should be much smaller
than the shower leakage between the same cells, in order not to distort
the coordinate reconstruction.

Eugene

On Fri, 2 Jul 2010, Zisis Papandreou wrote:

> Hi folks:
>
> I spent Wednesday at LNF, Frascati.  I spoke extensively with Stefano
> Miscetti about many things.  In this email I want to relay the KLOE
> experience in gluing their light guides (much bigger in area per unit
> than ours).
>
> The method they followed, in broad strokes, is to rotate each module
> so that it was vertical (long axis pointing up-down) and then they
> glued all light guides as a single unit on each module's end.  They
> had a jig made to hold them together as a unit.  They applied a
> carefully measured amount of epoxy (probably BC600, but definitely
> nothing with fast UV curing properties) and let it set overnight.
> There was some capillary action/seepage of epoxy between light guides,
> but it was confined to a few mm length along the main axis of the
> light guides.  They measured the optical cross talk that resulted from
> this and it was only a few percent, so it did not hurt reconstruction
> and it may have even helped by "smoothing" out the cluster distribution.
>
> The technician who was a  master at doing this is still at the lab,
> although close to retirement.  Tim, if you wish to have more details
> than this, please let me know and I can relay your questions to Stefano.
>
> As many of you know, their collaboration is working towards KLOE-2, an
> upgraded detector, with plans to employ SiPMs.  They are currently
> testing several Hamamatsu 1x1mm2 and 3x3mm2 SiPMs and they are also
> interested in arrays.  Stefano plans to email Carl Zorn and Fernando
> to get their wisdom on the SiPMs and electronics.  They are also
> thinking of using these devices in other experiments.  Stefano is also
> thinking to send one of his group members to Fermilab on their work
> there, and then have to person stop over at JLab for one day of
> discussions.  When he fixes his plans, I guess he will contact Elton
> to make arrangements.
>
> Cheers, Zisis...
>
> ---
> Dr. Zisis Papandreou		|  email: zisis at uregina.ca
> Department of Physics	|  tel. : (306) 585-5379
> University of Regina		|  tel. : (306) 585-4149
> Regina, SK  S4S 0A2		|  fax. : (306) 585-5659
> World Wide Web:   http://web.me.com/zisis/professional/
>
>
>
>
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