[Beowulf] Re: ECC Memory and Job Failures (Huw Lynes)

[Gerry Creager]

Robert G. Brown wrote:
> On Fri, 24 Apr 2009, John Hearns wrote:
> 
>> 2009/4/24 Robert G. Brown <rgb at phy.duke.edu>:
>>>
>>>
>>> I don't think memory is all that unstable, especially down where I live.
>>> In Denver, maybe.  I think you need a lot of RAM, for a long time, to
>>> see a lot of radiation induced errors, or a source of high energy
>>> particles.
>>
>> I thought more of a motherboard of RAM chips - which were flat in
>> those days (mumble) years ago, and putting a radiation source directly
>> above them. Poor man's silicon strip detector.
> 
> I vaguely remember an article long ago where somebody opened a RAM chip
> and hooked it up so that they could play with the timing refresh.  RAM
> is sensitive to light.  They wrote an array of ones while projecting an
> image onto it, waited a suitable amount of time, and could read the
> image out of the memory in 1's and 0's where the light hitting the array
> discharged the caps.  A poor man's camera.
> 
> Hmmm, let's see.  Yeah, there is even a patent somebody filed for this
> (GIYF).
> 
> So this might work if you had enough flux.
> 
> Hah!  Google IS your mighty friend!  Google up:
> 
> Radiation Dosimetry Using Three-Dimensional Optical Random Access
> Memories
> 
> Hmm, people make cheap neutron detectors out of DRAM.
> 
> So I guess this would work, but I still think you need a pretty peppy
> particle.  The article suggests 0.5 MeV or up.

This is the process that led to the original CMOS imaging chips.  And, I 
still use one for visible light astro-imaging.

gerry
-- 
Gerry Creager -- gerry.creager at tamu.edu
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