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Re: Phase II
Hi Elke,
In order to keep things in perspective, I suggest we get a schedule
(time line) from SensL. There is a non-specific mention of schedules on
page 15/15 of the proposal.
Regards,
Fernando
Elke-Caroline Aschenauer wrote:
> On Wed, 16 Jan 2008, Fernando J. Barbosa wrote:
>
> Dear Fernando,
>
> some remarks below.
>
> cheers elke
>
>
>> Hello everyone,
>>
>> I have a few comments regarding the proposal for phase II:
>>
>> 1. WP1.1 and WP1.2 are tests based on existing devices. I presume that
>> the deliverables are provided for confirmation of their results, perhaps
>> the best of the samples.
>> a. Are we going to learn anything else from any additional tests we
>> perform on the very few samples (5) compared to their test population
>> (100)?
>> b. The SensL report on the 100 samples will show the variation in the
>> specifications (gain, etc), both electrical and optical. Will there be a
>> direct correlation between these samples and the ones used in the arrays
>> under WP1.3? WP1.3 is a new production run.
>>
>
> 5 is not a big statistics. I think before we can decide the test at sensl
> are sufficient we need to know what they are in detail, see my original
> email. In addition the cost is negligible we should get them, just for
> the
> fact we might have some additional ideas on what could be tested or could
> do something Sensl cannot do. Of course the fact that 5 is a low
> statistics is still true.
>
>
>> 2. WP1.3 is a new production run. Here, I think, is the place to really
>> understand the variations in the specifications.
>> a. So, we need WP1.1 and WP1.2?
>> b. Carl has shown that trenching works in preventing/improving
>> cross-talk. Why not skip WP1.3 and WP2 and go to WP3? WP3 is a new wafer
>> run, as WP1.3.
>
> we have seen tranching working on a 1mm^2 SiPMT, it is always good to see
> nothing influences the production process going from something small to
> something bigger. My experience showed things very often don't simply
> scall from a small scale prototype to a fiull scale one.
> And producing silicon is still an bit of woodoo.
> I also think making small steps at a time allows much better to track
> when
> things started to fail.
>
>>
>> 3. The deliverables for WP3 are summed glass arrays where the 4x4 cells
>> (or dies) are connected in parallel to provide a single output, labeled
>> as a sum. The capacitance of this combination may be high and degrade
>> the timing characteristics considerably. A pixellated array may be
>> provided easily and cheaply by using a glass substrate with individual
>> outputs. SensL already provides this version, as shown in figure 1 on
>> page 11/15. Therefore, I propose the following with this wafer run:
>> a. 4x4 array on glass with parallel arrangement.
>> b. 4x4 array on glass with individual outputs. We can measure the
>> crosstalk at this level. We can also measure the capacitive effects due
>> to paralleling the cells. And we can sum the 16 outputs with an external
>> active circuit. This, of course, would increase the power dissipation
>> but improve the timing characteristics due to reduced capacitance.
>>
>
> I think I agree with you to have 5 arrays with tranching in a summed
> and 5
> arrays with trenching in as Sensl calls it pixellated output.
> We could such completely skip deliverable WP2.
> I think we should get their electronics as described in WP4 we can still
> look to do something better for the pixellated readout arrays.
>
>> As a side note, I recently (~ 2 years) completed a project for a Hall B
>> detector prototype using a Burle 85011 (64 anodes). For good timing
>> resolution, to conserve power and to reduce the number of channels, we
>> decided to parallel only 4 anodes before actively summing to a single
>> output. I have attached a report for your information.
>>
>> 4. Another concern, as some of you have mentioned, is cooling of the
>> array for gain stability via temperature control. This is not mentioned
>> at all in the proposal for phase II. Carl Jackson mentioned, at the
>> meeting at Jlab on 7 Jan, that SensL would use a different package to
>> implement cooling of the array. He mentioned a metallic hermetic
>> package. In any case, I suggest we add this to the baseline design
>> because we know we are going to need it. I also believe we may need to
>> have some control over the setting as the ambient characteristics in the
>> Hall will change over time, unless we have some reasonable good control
>> of the temperature in the Hall.
>
> I agree, that was always the plan.
>
>
>>
>> Regards,
>> Fernando
>>
>>
>>
>> George Lolos wrote:
>> > Hi Elke:
>> >
>> > First, can I ask you a small favour? When you reply to an e-mail but
>> > you change the subject material, like the one below, can you also
>> > change the subject title? It makes identification of pertinent
>> > material much easier both on selecting for prompt reading and later on
>> > when one searches for content.
>> >
>> > I agree with you on the fact that right now the main issue is the
>> > non-uniformity of gain among cells in an array and among arrays. So
>> > having the emphasis on these makes a lot of sense.
>> > Some more specific comments, below:
>> >
>> >
>> > Elke-Caroline Aschenauer wrote:
>> >
>> >> On Tue, 15 Jan 2008, Zisis Papandreou wrote:
>> >>
>> >> Dear all,
>> >>
>> >> I think we have to make progress on the SoW with sensl. I went
>> >> through the
>> >> contract and it looks much more resonable compared to the one before.
>> >> For the moment they leave the increase of PDE out, which I think is
>> >> reasonable and is what was suggested to Calr Jackson the last time.
>> >> Becuase having SiPMTs in hand which ave no gain variations, low noise
>> >> and
>> >> cross talk, good electrical behaviour and timing structure woule be
>> >> extremely important. The increase in PDE can follow.
>> >> I like a lot that they will provide for quite some points test
>> samples
>> >> which allow readout of the individdual 3x3 SiPMTs in the array.
>> >>
>> >> I have only very little points for a discussion.
>> >>
>> >> Page 6 point 3 WP1
>> >> ---> after the results of Carl Zorn on gain variations vs bias
>> >> voltage do
>> >> we consider a value of 10% inside one module adequate. I do not.
>> >>
>> >
>> > If the gain variations within cells of an array remain within 10% I
>> > don't see the problem. I miss the connection to your statement about
>> > bias variation. As long as the cells exhibit maximum 10% variation in
>> > gain, what does the bias voltage mean? Maybe I didn't understand your
>> > comment?
>> >
>> >> page 6
>> >> ---> I would like a detailed list of what intensive electrical and
>> >> optical
>> >> tests mean and which test addresses which problem
>> >>
>> >
>> > I agree. The only obvious connections are the definition of breakdown
>> > voltage and whether a wafer and/or cell show a higher dark current
>> > than others, indicating poor Si or treatment.
>> >>
>> >> ---> I see no mention of the integration of the temperature
>> >> stabilisation
>> >> in the electronics.
>> >>
>> >
>> > I am baffled by this so I must have missed something. If we don't go
>> > with cooling, as we all agree, how can we stabilize the effects of
>> > temperature variations with electronics alone?
>> >
>> >>
>> >> the only other question are 5 arrays per setting enough, I would
>> >> think so.
>> >>
>> >> In addition ot the SoW with Sensl, we have to start thinking about
>> >> spcifications for the glue, lead and all other material that is
>> >> needed to
>> >> build the modules.
>> >>
>> > We had looked at other (cheaper) epoxies for the matrix of lead and
>> > SciFi. However, we could not find any obvious advantages over the
>> > BICRON 600 we have been using and KLOE also used. We know BICRON 600
>> > has good strength and does not chemically attack the SciFi material so
>> > we have long concluded on BICRON 600. As for the lead, what do you
>> > mean? We have submitted test reports clearly stating we need pure
>> > lead because any alloying results in problems with swaging. What we
>> > do need to resolve is whether we change the sampling fraction of the
>> > first couple of layers or not. So, in my opinion we have
>> > specifications for all items needed for construction.
>> >
>> >
>> > Cheers,
>> >
>> > George
>> >
>> >>
>> >> Can we actually progress with the fiber specifications, Elton do we
>> >> have a
>> >> list of measurments we need from the bicron and kuraray fibers we
>> >> ordered.
>> >>
>> >> That is all I have for the moment.
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>> 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 +
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>> >> | | ;--' | Mail: elke@jlab.org Mobil: 001-757-256-5224 -
>> >> '--' `-.--.
>> | +
>> >> \_ | |---' Tel.:
>> 001-757-269-5352 =
>> >> `-._\__/ Fax.:
>> 001-757-269-6331 -
>> >>
>> +=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+
>> >>
>> >>
>> >>
>> >
>> >
>>
>
> ( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
> ) `\ -
> / '. | +
> | `, 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 -
> +=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+
> ------------------------------------------------------------------------
>
> begin:vcard
> fn:Fernando J. Barbosa
> n:Barbosa;Fernando J.
> org:Jefferson Lab
> adr:Suite #10, 12B3;;12000 Jefferson Ave.;Newport News;VA;23606;USA
> tel;work:757-269-7433
> version:2.1
> end:vcard
>
begin:vcard
fn:Fernando J. Barbosa
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tel;work:757-269-7433
version:2.1
end:vcard