"Don Foreman" wrote in message
...
Anybody know how these work? Is there a solid-state replacement for
a GM tube that works on low voltage?

A special version of static RAM will do that. RAM is usually passivated and
also shielded by a glass layer that's supposed to suppress "cosmic ray" hits
that destroy the contents of cells. Without the shielding, the contents
will dump proportionally to the amount of radiation received.

I _don't_ know if any commercial devices are built on this principle,
though.

LLoyd