It seems to me there are two problems here:
1. Getting rid of the heat altogether, and from the comments I've seen,
that will
apparently need to be by radiation. "In space, no one can..."
Merely dunking things in liquid will just get you hot liquid. And
I'd be concerned
about the chip packages' leak integrity.
2. Also you need to carry the heat from source to the radiator without
excessive
temperature difference.
My point is, don't forget the radiator. Then ask, perhaps, "Can I just
attach the
chips to the radiator?". Perhaps this is already what Jason is getting
at, but he
didn't say how his "heatsink" was going to dispose of the heat.
Dana Whitlow
Arecibo Observatory.
On 4/16/2013 7:03 AM, Francois Kapp wrote:
Hi Brad,
Given it's a balloon payload, what are your mass constraints?
Conductive cooling is going to involve throwing metal at the problem,
possibly a lot of metal...
-Francois
On Tue, Apr 16, 2013 at 12:57 PM, Steve Maher
<[email protected] <mailto:[email protected]>> wrote:
Heatpipes and dunking
<http://www.pugetsystems.com/submerged.php>in liquid (e.g. mineral
oil) are options we've explored (with PCs), although we seem to be
favoring pressure vessels at this point.
Steve
On Tue, Apr 16, 2013 at 2:34 AM, Jason Manley <[email protected]
<mailto:[email protected]>> wrote:
I don't know of anyone who's actually done this, but we do
also have a passive-cooled concept for our new digitiser board
(loosely based on ROACH2). We've been thinking about a
prototype that'd essentially be turning a ROACH2 board
upside-down and bolting it onto a giant metal plate that's
been appropriately milled out of a solid chunk of alu. The
FPGA, PPC, QDR and other hot bits would make contact with the
plate and use it as heatsink. The other high-profile parts
(RAM DIMM, for example) needs holes or cavities milled out the
alu.
I think Vaughan (cc'd here) might have some mechanical
drawings of ROACH2 with the holes and things in the
appropriate place. It might help you get started. He could
also provide some CFD models and heat load measurements of the
various components.
Jason Manley
DSP Specialist
SKA-SA
Cell: +27 82 662 7726 <tel:%2B27%2082%20662%207726>
Work: +27 21 506 7300 <tel:%2B27%2021%20506%207300>
On 15 Apr 2013, at 20:29, Brad Dober wrote:
> Dear Casper Collaboration Members,
>
> My name is Brad Dober, and I'm a grad student at UPenn
working on a ROACH-based MKID readout for a balloon payload.
At our float altitude, air-cooling the ROACH and ADC/DACs
isn't feasible Has any other group looked into or even
designed a conduction-cooled system for .either the ROACH1 or
ROACH2?
>
> Any leads would be extremely helpful.
>
> Sincerely,
>
> Brad Dober
> Ph.D. Candidate
> Department of Physics and Astronomy
> University of Pennsylvania
> Cell: 262-949-4668 <tel:262-949-4668>
--
Francois Kapp
Sub-system Manager
Digital Back End
meerKAT
SKA South Africa
Third Floor
The Park
Park Road (off Alexandra Road)
Pinelands
7405
Western Cape
South Africa
Latitude: -33.94329 (South); Longitude: 18.48945 (East).
(p) +27 (0)21 506 7300
(p) +27 (0)21 506 7360 (direct)
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