Effect of radiation on computers

[M.Williamson@mailbox.uq.oz.au (Michael Williamson)]

Here is a question which I noticed on a usenet newsgroup and which the
poster  has asked me to send to radsafe:

From: Jim Ronback (jronback@direct.ca)

What is the effect of background ionizing radiation on commercial computers?

How often will high energy particles from solar
flares, cosmic rays, residual radioactive decay in solder (lead used be
uranium millions of years ago) and in encapsulating materials cause
anomalous behaviour in a PC / workstation / net server? Is there any data
available which would allow me to estimate the liklihood of having one or
more bits flipped in memory or processor registers in
commercial computers which do not have radiation hardened devices?
If the likelihood is high enough then perhaps one should not use single
bit flags in safety critical software.

Any advice or pointers would be appreciated.

Jim Ronback, P.Eng.
Senior Safety Engineer
Hughes Aircraft of Canada Ltd.,
13951 Bridgeport Road
Richmond, B.C
Canada  V6V 1J6

Tel: 604 279 5789



Michael Williamson
                                        ph +61 7 3365 4504
Radiation Protection Adviser            fax +61 7 3365 1577
Occupational Health & Safety Unit       m.williamson@mailbox.uq.edu.au
University of Queensland
Brisbane 4072
Australia