[Rich] Fwd: Re: Dark Current

[mirazita]

Dear all,
here some clarification from Hamamatsu on the results of the jlab MAPMT
tests.

Marco


-------- Original Message --------
Subject: Re: Dark Current
Date: Tue, 1 Jul 2014 00:14:49 +0200
From: aversa at hamamatsu.it
To: mirazita <Marco.Mirazita at lnf.infn.it>

Ciao Marco,
di seguito le risposte del Giappone ai due quesiti:

Regarding higher dark current at pixel #57, we think four pixels at each 
corner (#1, #8, #57 and #64) tend to have a bit higher dark current than 
the other pixels have, since corner pixel adjoins to metal envelope, to 
which HV is applied, by two sides and high voltage difference between 
metal envelope and anode pixel might cause a higher dark current.

Regarding detection efficiency, we compared cathode blue sensitivity index

of 10 pcs of the H12700B with 80 pcs of the H8500D which we shipped to 
Jlab, and noticed the H12700B has a higher sensitivity on average. In 
addition, the H12700 should have a higher collection efficiency than the 
H8500 and thus, we think it is natural the H12700B had higher p.e. than 
the H8500D.

un saluto

Massimo

Phone:         +39 06 50513454
Fax:                +39 06 50513460
            
Email:                                   aversa at hamamatsu.it
Web:                                    www.hamamatsu.it
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Viale Cesare Pavese, 435
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