Re: SiPM cooling

[Elton Smith <elton@jlab.org>]

HI Zisis,

See notes below:

On Fri, 9 Mar 2007, Zisis Papandreou wrote:

> Hi Elton et al:
>
> following the meeting with SensL last month, we were asked to
> investigate the following, in connection to the cooling of the 4x4
> Sensor Arrays (SA), each consisting of 16 3x3mm2 cells.
>
> 1. What are the plans for the control of temperature and humidity in
> Hall-D?  This is a civil engineering question.  Can you point us to
> info on this?  SensL brought up the number of <15% humidity in the
> Hall.  Is this achievable, and if not can it be made a goal?

Civil design conditions for the hall are 70deg, 55% humidity.

The conventional facilities design criteria can be found from you jlab
account at the following directory:
/group/planteng/12_GeV/Design/Hall_D_Design/
Space_Program_Design_Criteria/Space_Program_Design_Criteria_v1-0.doc

I do not know how achievable the <15% humidity requirement would be in
humid Virginia, nor do I know if that is desirable. For such low levels of
humidity other problems arise, so even considering this as a goal should
be thought through. For the moment, I think we need to consider options
with our standard humidity conditions for the hall.

>
> 2. 'Global cooling' of all 4224 SAs for the BCAL was discussed.  What
> are thoughts from JLab engineers on this?  Can we achieve air flow,
> nitrogen flow, or water cooling over the SA region?  We are talking
> about a doughnut-shaped enclosure for gas flow, and something else
> for liquid flow.  Also, above dew point and below dew points options
> should be discussed.  With SensL we are working towards a above dew
> point option, which will still provide us with a factor ~5 decrease
> in the DR from cooling.
>
Tim Whitlatch has been working on the cooling system for the FDC, but we
have also given him some numbers for the Bcal and it only makes sense to
design a single system to handle all cooling requirements inside the
solenoid.

> Cooling individual SAs is expensive.  SensL gave us a number of US
> $200 per SA (not firm, just approximate at this stage) for *bare*
> SAs.  Adding the cooling and TEC to this, adds another US$160 to the
> price.  Clearly, there is strong motivation from cost (and
> complexity) in pursuing a global cooling solution.  JLab needs to
> take the lead on this, since Regina has no engineering expertise.

What do you mean by cooling individual SA's? Is this to remove the heat
generated by the Peltier junction to the outside?


>
> Cheers, Zisis...
>
> -----------------------------------
>  From Padraig:
>
> In answer to your question, the energy dissipation from the detector is
> minimal - 300uW based on a 30V bias with upto say 10uA current draw.
> This scales with number of detectors.
>
> For the electronics
> At room temp 6-7mA of current draw at 5V gives about 60mW
> Cooled this goes up by an order of magnitude.
> -----------------------------------
>
>
> ---
> 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/
>
>
>