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Re: Si PMs proposal



On Wed, 16 Jan 2008, Elton Smith wrote:

Dear Elton,

some small remarks below.

cheers elke

>
> HI Zisis,
>
> Just responding to the question of the latest SiPM proposal. I agree we
> need a smaller group, and also a draft sow from our side to clarify what
> we would like to see. Here is my initial reaction to the draft 4.1 from
> SensL. Some of these comments support Elke's previous response.
>
> p. 6, should be called gain uniformiy (not optimization)
> - goals are clear
> - should the wafer level testing not come first?
>
> p. 7.
> The following statement "This (0.2 volts variations) is not thought to
> be sufficient a variation to provide for the that are seen at the
> glass array package level." is not supported by Carl's measurements. We
> need to make sure we clarify this with Carl Jackson. If you look at slide
> 32 from George's presentation at the collaboration meeting, Carl's
> measurements show that the gain changes from 240 down to 80 from a change
> in bias from 1.1 down to 0.9V (this is a factor of 3). If we believe it
> scales as a ratio to the voltage over breakdown, then for a nominal
> setting of 2V, 0.2 V variation might be reduced to 1.5 (50%). These are
> substantial changes in gain. Clearly other factors in the variation of
> gain need to be checked but the tracking changes in breakdown voltage
> should be further quantified.
>

I totally agree and that was my point for Page 6 point 3 WP1


> p. 9 and 10: Work Packages 2 and 3: Crosstalk and Trenching
> These are important issues, but in a priority list I would put them after
> the issue of timing. This is because at the moment these do not seem like
> they are limiting their use.

for Trenching I totally agree. But as discussed we would like to see the
electrical cross talk between the 3x3mm^3 SiPMTs of an array.
I mentioned this already during the meeting with Carl Jackson, we can
easily address this with the arrays which have not all the individual
3x3mm^3 SiPMTs summed. But that does not need any development. Si arrays
are also very important for the gain uniformity studies.

>
> p. 11, Timing resolution
> It is claimed that "SensL has demonstrated that it is possible to achieve
> intrinsic timing resolution capability ... on 1mm SPM." I would like to
> see this data; it might have been shown but I missed it. It is still my
> concern that this is an issue. And we clearly need to proceed beyond the 1
> mm SPMs to 3x3mm2 for verification before applied to the SPM arrays.

I don't think we have seen this for bigger SiPMTs.

>
> Here the deliverables emphasize the electronics, but initially the
> intrinsic timing should be verified without electronics. The electronics
> should be checked separately, and I am confident that this can be achieved
> with a proper design.

absolutely, this should be easy to do if we have the arrays with the nice
connectors we saw.

>
>
> Once we agree on the priorities, we can put together a draft sow.
>

I think gain and timing are of highest priority, what I'm a bit suprised
is there is no mentioning of dark counts at all.
Trenching and cross talk on pixel level and on electronics level is for
sure the lowest one.

>
> Cheers, Elton.
>
>
>
>
> > SensL and Proposal
> > ================
> >
> > Elke, for this meeting we need a smaller group of people (you, Elton,
> > George, Andrei, Carl and possibly Fernando).  Can you guys propose a
> > time to discuss the new SensL proposal?  Friday or Monday afternoon
> > would be ok for Andrei and me.
> >
> > Cheers, Zisis...
> >
> >
> > >
> > >> Date: Tue, 15 Jan 2008 17:17:42 -0600
> > >> From: Zisis Papandreou <zisis@uregina.ca>
> > >> To: Hall-D Collaboration <halld-collab@dustbunny.physics.indiana.edu>
> > >> Subject: [GlueX] Calorimetry Group Meeting - Jan 18
> > >>
> > >> Hello folks:
> > >>
> > >> I have two issues in this email.
> > >>
> > >> 1.  Day of the week and time of our periodic Calorimetry Group
> > >> Meetings.  There is a suggestion from JLab to reserve Friday's at
> > >> 10-11am for our meetings.  This does not mean that we will have a
> > >> meeting every week, it is just that we are trying to find a time that
> > >> works for all active participants of our group, considering the 8
> > >> time zones between Regina through the East Coast to Athens (9 in the
> > >> summer, but we will revisit this at the time).
> > >>
> > >> Please let me know if this time slot does not work for you.
> > >>
> > >> 2. I would like to schedule a meeting this Friday, Jan 18, so please
> > >> reply to question 1 right away.  The meeting is tentatively scheduled
> > >> for 10am, unless I hear an uproar.  The main topic is the work
> > >> towards the Calorimetry Document, but other issues can be discussed.
> > >>
> > >> http://www.jlab.org/Hall-D/software/wiki/index.php/January_18%
> > >> 2C_2008_Calorimetry
> > >>
> > >> Cheers and thanks, Zisis...
> > >>
> > >> ---
> > >> Dr. Zisis Papandreou		|  email: zisis@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://www.phys.uregina.ca/sparro/zisis/
> > >>
> > >>
> > >>
> > >
> > >  ( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
> > >   )    `\                                                  -
> > >  /    '. |                                                  +
> > >  |       `,              Elke-Caroline Aschenauer            =
> > >   \,_  `-/                                                    -
> > >   ,&&&&&V         Jefferson Lab                                +
> > >  ,&&&&&&&&:       HALL-D 12C / F381       121-A Atlantic Avenue =
> > > ,&&&&&&&&&&;      Mailstop: 12H5          Hampton, VA 23664      -
> > > |  |&&&&&&&;\     12000 Jefferson Ave                             +
> > > |  |       :_) _  Newport News, VA 23606  Tel.:  001-757-224-1216  =
> > > |  |       ;--' | Mail:  elke@jlab.org    Mobil: 001-757-256-5224   -
> > > '--'   `-.--.   |                                                    +
> > >    \_    |  |---' Tel.:
> > > 001-757-269-5352                             =
> > >      `-._\__/     Fax.:
> > > 001-757-269-6331                              -
> > >             +=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-
> > > +=-+=-+
> > >
> >
> > ---
> > Dr. Zisis Papandreou		|  email: zisis@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://www.phys.uregina.ca/sparro/zisis/
> >
> >
> >
>
>

 ( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
  )    `\                                                  -
 /    '. |                                                  +
 |       `,              Elke-Caroline Aschenauer            =
  \,_  `-/                                                    -
  ,&&&&&V         Jefferson Lab                                +
 ,&&&&&&&&:       HALL-D 12C / F381       121-A Atlantic Avenue =
,&&&&&&&&&&;      Mailstop: 12H5          Hampton, VA 23664      -
|  |&&&&&&&;\     12000 Jefferson Ave                             +
|  |       :_) _  Newport News, VA 23606  Tel.:  001-757-224-1216  =
|  |       ;--' | Mail:  elke@jlab.org    Mobil: 001-757-256-5224   -
'--'   `-.--.   |                                                    +
   \_    |  |---' Tel.:  001-757-269-5352                             =
     `-._\__/     Fax.:  001-757-269-6331                              -
            +=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+