[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: SiPM cooling



Hi Elton:

thanks for the quick feedback.  Just a few comments below.

On Mar 9, 2007, at 1:57 PM, Elton Smith wrote:


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.

Ok, we'll work with these conditions for now.


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.

Indeed, I agree with this.  Some enclosed system in any case will not have to worry about the 55% humidity in the hall.


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?

I was referring to the entire cooling process, from the SiPM contact through the Peltier cooling to the environment.

Ciao, Zisis...




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/





---
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/