Half-life of EC-Decay Isotope in Fully Ionized Plasma

Since electron capture decay isotopes capture the inner most electron which
has a precise energy and location distribution, I was curious how the
electronic state of an atom like Ca-41 affects half-life? Ca-41 at STP has
a half-life of about 1e5 years. What's Ca-41's half-life in a fully ionized
plasma or in a white dwarf?

Since electron capture decay isotopes capture the inner most electron which
has a precise energy and location distribution, I was curious how the
electronic state of an atom like Ca-41 affects half-life? Ca-41 at STP has
a half-life of about 1e5 years. What's Ca-41's half-life in a fully ionized
plasma or in a white dwarf?

Dear jim:

"jim" wrote in message
...
Since electron capture decay isotopes capture the inner most electron
which
has a precise energy and location distribution, I was curious how the
electronic state of an atom like Ca-41 affects half-life? Ca-41 at STP
has
a half-life of about 1e5 years. What's Ca-41's half-life in a fully
ionized
plasma or in a white dwarf?

For what it is worth, this is also called electron capture/positron
emission. I don't think that one has preference over the other.

David A. Smith

"jim" wrote in message
...
Since electron capture decay isotopes capture the inner most electron
which
has a precise energy and location distribution, I was curious how the
electronic state of an atom like Ca-41 affects half-life? Ca-41 at STP
has
a half-life of about 1e5 years. What's Ca-41's half-life in a fully
ionized
plasma or in a white dwarf?

So far the only phenomena we know that can affect the half-life of
radioisotopes are bombarding the nucleus itself with particles or radiations
that intertact with the internal energy levels of the nucleus.

[I started a research project some years ago investigating whether or not
the NMR experiment can be used to stimulate *coherent* radioactive decay in
analogy to LASER and MASER experiments, but there were funding problems...]

EC decay is also accomplished by positron emission (PE).

The nuclear environment of a plasma or a white dwarf is very rich in
high-energy electrons.


Tom Davidson
Richmond, VA

"tadchem" wrote in message
...

"jim" wrote in message
...
Since electron capture decay isotopes capture the inner most electron
which
has a precise energy and location distribution, I was curious how the
electronic state of an atom like Ca-41 affects half-life? Ca-41 at STP
has
a half-life of about 1e5 years. What's Ca-41's half-life in a fully
ionized
plasma or in a white dwarf?

So far the only phenomena we know that can affect the half-life of
radioisotopes are bombarding the nucleus itself with particles or
radiations
that intertact with the internal energy levels of the nucleus.

[I started a research project some years ago investigating whether or not
the NMR experiment can be used to stimulate *coherent* radioactive decay
in
analogy to LASER and MASER experiments, but there were funding
problems...]

EC decay is also accomplished by positron emission (PE).

Could you please describe this or provide a citation as I've not heard of
postrons with Ca-41 before and it's not in any of the decay/isotope
listings. Ca41 - K-41 + neutrino + X-rays from the electrons filling in
the inner most shells.

The nuclear environment of a plasma or a white dwarf is very rich in
high-energy electrons.

Exactly but is any old high energy electron suitable from a Ca-41 nucleus to
capture? If high energy electron are captured more easily then the
half-life of Ca-41 should decrease in a fully ionized plasma??

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox wrote in
message news:56xsc.24389$PU5.22811@fed1read06...
Dear jim:

"jim" wrote in message
...
Since electron capture decay isotopes capture the inner most electron
which
has a precise energy and location distribution, I was curious how the
electronic state of an atom like Ca-41 affects half-life? Ca-41 at STP
has
a half-life of about 1e5 years. What's Ca-41's half-life in a fully
ionized
plasma or in a white dwarf?

For what it is worth, this is also called electron capture/positron
emission. I don't think that one has preference over the other.

What about the neutrino, there's no positron?

Dear jim:

"jim" wrote in message
...

"N:dlzc D:aol T:com (dlzc)" N: dlzc1 D:cox wrote in
message news:56xsc.24389$PU5.22811@fed1read06...
Dear jim:

"jim" wrote in message
...
Since electron capture decay isotopes capture the inner most electron
which
has a precise energy and location distribution, I was curious how
the
electronic state of an atom like Ca-41 affects half-life? Ca-41 at
STP
has
a half-life of about 1e5 years. What's Ca-41's half-life in a fully
ionized
plasma or in a white dwarf?

For what it is worth, this is also called electron capture/positron
emission. I don't think that one has preference over the other.

What about the neutrino, there's no positron?

URL:http://www.nndc.bnl.gov/nndc/nudat/lagform.html
with a mass number of of 41 and atomic number of 20. Quite a band of
possible energies.

URL:http://environmentalchemistry.com/yo...ic/Ca-pg2.html
this does not indicate a decay mode including positron emission.

URL:wcuvax1.wcu.edu/~liming/phys310/ guides/chap13/chap13dn.doc
this one is a ".doc". It indicates the probability of EC vs. PE is based
on the mass of the resulting nucleus. For K40, the nucleus mass of Ar40 is
about 2 electron masses lower, so positron emission is less likely.

We are bathed in neutrinos, so it would be difficult to image them. A
neutrino and a positron are emitted together. The positron from any
possible Ca41 decay would quickly find an electron to pair with in the
plasma of a star. With low mass and high charge, I would not even expect
to see positrons from our own Sun.

David A. Smith