Re: Understanding PDE information (fwd from Richard)

[Elton Smith <elton@jlab.org>]

---------- Forwarded message ----------
Date: Wed, 18 Apr 2007 16:45:40 -0400
From: Richard Jones <richard.t.jones@uconn.edu>
To: Elke-Caroline Aschenauer <elke@jlab.org>
Cc: George J. Lolos <George.Lolos@uregina.ca>, Elton Smith <elton@jlab.org>
Subject: Re: Understanding PDE information

Dear Elke,

Fill-factor is important from the viewpoint of the manufacturer, but for
the detector builder I claim that only the PDE is relevant.  From what I
understand, there are trade-offs in device performance between fill
factor and QE/DR optimization so we cannot assume that fill factor can
be increased without compromise in some other area of the performance.
In our discussion I think we should leave manufacturer's details aside
and only speak of actual performance characteristics: PDE, DR at a
certain temperature and bias over-voltage.  This is what Carl has done,
and what I seek to do in my comparison.

Richard J.

Elke-Caroline Aschenauer wrote:
> On Wed, 18 Apr 2007, Richard Jones wrote:
>
> Dear Richard,
>
> I think we have to be careful again comparing numbers.
> the PDE depends on the breakdown voltage (carls talk page 11 not counting overlays), which you have taken care of in your comparision, but it also depends on the fill factor (zisis talk page 5 and 7)
>
> PDE = Q_E*alpha*F
>
> so what is the fill factor for your Photonique SiPMTs and than you have 2mm x 2mm active area and the ones from carl a 1mm x 1mm, I think we should also account for this, like Carl does in his eq on page 9.
>
> Maybe I'm wrong.
>
> Cheers elke
>