?? Ra-226 in computor tubes -Reply

[FRAMEP@ORAU.GOV]

Alan:

Let me try some guesses - nothing definate.

> Why Ra-226? 

I suspect it was probably used for the same reason some newer tubes
use Kr-85/H-3/Pm-147 etc. In at least some situations, the
radioactive source can replace a heated cathode with a more constant
emission of charged particles at a uniform energy. At the time,
Ra-226 was readily available and not the pariah it is today. My
limited info, probably unreliable, is that tubes employing
radioactive sources were frequently used for voltage regulation
purposes. Your tubes might be a completely different matter however.

>How much was used per double tube?  

Since you've got gamma spec capability, the best way to determine
this would be to measure it. Sorry I don't have anything else to
offer on this one.

>Disposal problems??

I cracked a radium-containing tube one time, a Western Electric 34SB,
and much to my dismay, the radium spread around - at least some of it
was in a loose form.

Best of luck

Paul Frame
Oak Ridge Institute for Science and Education
Professional Training Programs
framep@orau.gov