Re: Effect of radiation on computers

[bflood@SLAC.Stanford.EDU (Bob Flood)]

I'm not sure if I missed a reply or 2, or if this aspect just hasn't been
discussed, but there is a side of potential radiation-induced damaged that I
don't believe has been addressed yet. While Radsafers have contrinuted their
knowledge about radiation-caused damage to silicon and other computer
materials, they haven't discussed the possibility of radiation-induced
changes of zeroes and ones. All computer chips store whatever the chip is
made for as zeroes and ones, and each one has the potential to be changed
(flipped to its opposite) by ionizing radiation. In fact, there was
sufficient interest in this phenomenon to begin research into a computer
chip-based dosimeter a few years ago. I never heard any results, nor do I
have any references onthe subject. Perhaps other may.

This aspect may be of greatest interest to users. Nuclear plants that place
PCs in posted radiation areas for access control and other purposes may find
intermittent operating problems (apparently random) that may go undiagnosed
as radiation induced. The probability of a bit-changing event would be
compounded by the probability of changing a bit of any real importance
(fatal vs non-fatal errors) in a device of real importance to the computers
and its applications. Bit changes may be happening regularly on some
machines, but generally go un-noticed because the effects of most bit
changes are trivial (changing the spelling of a word in a menu, the color of
a pixel on a screen, etc.). Only those changes that cause a detecable error
or failure to function would attract attention.
Bob Flood
Unless otherwise noted, all opinions are mine alone.
(415) 926-3793
bflood@slac.stanford.edu