Beta-Voltalics Output: Radiation & Silicon Requirements

[Seth T]

Does anyone know what the output is like from beta-voltalics? And how much radiation is needed and how much silicon?
Thank you in advance.

 

[ZapperZ]

What is "beta-voltalics"?

It is not often that Google returns no listing.

Zz.

 

[Seth T]

A beta emitting isotope surrounded by basically a bunch of diodes. The beta particles put a charge into the silicon similarly to how light interacts with solar cells. I think.

 

[ZapperZ]

A beta emitting isotope surrounded by basically a bunch of diodes. The beta particles put a charge into the silicon similarly to how light interacts with solar cells. I think.

No kidding! Do you have a reference that describes this device?

It would be a rather "strange" device considering that this isn't a very good way to treat silicon.

Zz.

 

[Seth T]

I heard about it from a nuclear engineer from a power plant. I can't contact him right now as they are in shut-down. But I think that NASA used it some.

 

[ZapperZ]

Well, we have nuclear engineers here, so let's wait to hear from them as well.

Zz.

 

[Astronuc]

NASA has used thermionics and thermoelectrics, but I've not heard of a major application of beta voltaics. Someone might be confusing technologies.

OK - there's a bit on alpha and beta voltaics at NASA Glenn.

Power & In-Space Propulsion
http://www.grc.nasa.gov/WWW/5000/pep/photo-space/

The problem of beta-voltaics is the spectrum of beta particles, and the gammas, and the decrease of activity with time. The activity is proportional to the number of atoms of radionuclide present and the decay constant. The greater the decay constant, the greater the activity for an amount of radionuclide, but that means it decays more rapidly.

Basically in beta-voltaics, there is a collector collecting the beta particles, so the source is at a + charge, which causes a potential difference across which a load is placed. There is a disadvantage with the beta spectrum such that some betas don't make it out of the source material, so the dimensions have to be properly sized based on the peak of the beta energy spectrum.

 

[Seth T]

I know about thermoelectrics, but I think that this was something different.

 

[Astronuc]

See page 12 and 13 of this presentation.

http://energy.ece.uiuc.edu/ieee/.%5Cpresentations%5C34BB9MY5OT6A8GUQJS9OLBVC9.pdf

A somewhat descriptive article, but lacking in technical detail.

http://www.sciencedaily.com/releases/2005/05/050514205902.htm