One problem with the methods I suggested for distinguishing
dideuterinos from Helium in CF experiments is the possible large
amount of deuterium that might be present. This would could make the D
+ (m/Q) = 2 peak too large to accurately distinguish the amount of
added deuterons from a dideuterino ionization process. It should not
prevent the accurate detection and concentration determination of
Helium, however, because the He++ (m/Q) = 2 peak is still
distinguishable from the D+ (m/Q) = 2 peak.
One solution to a large D+ (m/Q) = 2 peak would be to filter the gas
to be tested through palladium, which readily adsorbs ordinary D2 and
thus removes it, and then test the residual gas for He, etc. This
could have the drawback that dideuterinos may be able to diffuse
through palladium even without an ionizing adsorbtion process. This
problem can be addressed by this procedure:
(1) measure the He content by ordinary mass spec.
(2) filter out the D2, and possibly some dideuterinos in the process,
using Pd filters
(3) measure He and dideutrino content from residual gas
(4) any large reduction in apparent Helium concentration is due to
dideutrino loss through the Pd filter
One thing that may help the process, if dideuterinos don't readily
diffuse through the cathode material, is to allow the CF cathodes to
degass the interior D2 prior to digesting of the cathode to obtain
the Helium/dideuterino gas for the mass spec. What a lot of work!
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
