Their mass is totally converted into a pair of high energy photons (two particles of light) of a characteristic wavelength, which is why detecting light of that wavelength (energy) is called a “signature.”

Radon, which is not light but is a gas and can be found high up and has many isotopes, and has a long decay chain down to the stable lead. There must be a beta+ there somewhere.

I found it in a plot correlating it with ionisation in the atmosphere but do not seem to have kept the link.

FROZEN LIGHTNING

And with Christmas coming, here it is with the lighted frames…
http://www.capturedlightning.com/frames/interesting.html

I think his blog hoster is glyching, or something. My post didn’t appear right away, and then I got an email saying there was a new post, but it wasn’t there until I refreshed my browser a couple of times.

None of those are natural isotopes so they would have to be produced in some atmospheric collision; perhaps by cosmetic rays. The 6C10 decay also emitts two gamma rays at 0.72, and 1.04 MeV, and ALL of those b+ decays are characterized by anihilation radiation which is the 511keV gamma from the anihilation of the positron.

The half lives of those beta decays range from 0.78 seconds for the Boron to 20.5 minutes. Well the Nitrogen12 is particularly unstable with a half life of 0.011 sec. But really all of those are relatively long lived compared to some of the transuranic isotopes.

So you need some atmospheric transmutation from CRs or somesuch collision to create one of those isotopes, or else you have to get a pair production event.

Note, that it is the light unnatural isotopes that decay by positron emissions. Then you go through the heavier stable natural isotopes, and then when you get to the heavier unstable isotopes they are b- emitters.

Talking about one element here such as Nitrogen in all its isotopic varieties.

Positron emission turns a proton into a neutron, so the atomic weight remains unchanged, but you go down one in the periodic table, so 7N12, and 7N13 decay to 6C12, and 6C13 respectively, both of which are stable.

So the neutron light isotopes are unhappy about that, and want to move down the periodic table to where they are happier; and conversely if you try to stash too many neutrons in the nucleus, they want to beta devcay by electron emission which turns a neutron into a proton, and moves you up the periodic table to the next element.

The lighter elements like a 1:1 neutron to proton ratio; but as you go higher up the table, it takes a higher fraction of neutrons to keep the nucleus stable.

It also seems that a nuclear neutron capture event from cosmic rays, produces a neutron rich isotope nucleus, which if unstable would decay by regular electron emission. So it would seem that a proton capture event is most likely to result in positron emission, in those lighter atmospheric elements.

Imagine a column of gas being heated by a multi-million volt
electric discharge. The gas will heat up. Molecules of gas will
speed away from the center of the column with great energy.
As they leave — radially — from the center of the column, a
vacuum is created. The discharge continues, and some of
the remaining particles get accelerated to very high velocities.

Photoelectric effects or very high local electric fields strip away
electrons, and perhaps even decompose water so there are
free protons around.

In a 100km long discharges happening 10^7 times a day, there will
be plenty of random, transient, high vacuum conditions a few meters
long.

Look at it the other way. How could this _not_ happen. How could
it be prevented?

George E. Smith (16:26:05) :

I was speaking at 9:30 of direct conversion of electron KE to the pair of particles. See my 15:30 post about why it is unlikely we can get electrons to a few Mev in the atmosphere.
I don’t think lightning does this directly…something else is up. “”"

Well I did catch that Kevin, and I have to admit to being a bit hazy on how such a mechanism would work.

But the important thing is that any such mechanism would produce a pair, so there is no charge creation problem that Jim was hinting at.

As far as I know the only way to get isolated positrons; rather than a pair creation is by the radioactive beta decay of some appropriate isotope; and that would be the result of either spontaneous decay of such an isotope or the result of a nuclear collision with some charged particle; well I suppose it could be neutrons as well generating temporarily on e of these isotopes that beta decays via positron emission.

The table of the isotopes in any CRC handbook of Chemistry and Physics, lists a huge number of positron emitter isotopes; and the ones that aren’t natural may be readily produced in nuclear collisions.

These days, positron emission is hardly earth shattering news; heck you can go to a clinic and get your picture taken inside and out with PET scanners.

People would freak out if you told them you wanted to take their picture with anti-matter.

They already had to change the name of Nuclear Magnetic Resonance imaging (NMR), to just Magnetic Resonance Imaging (MRI) because people freaked out over the “Nuclear” connotations.

I’ve been CAT scanned, and NMR’d; but I haven’t been PET’d yet.

But I don’t think that any free positron is going to hang around anywhere for very long; there’s just too much free electrons everywhere, and those things just like to anihilate positrons as soon as they encounter them.

At 96km meters the pressure is 10^-5 atmospheres, and the ionosphere goes up to 1000km I think.

I would expect the densities would be thin enough to allow for the tail of the electron distribution to travel enough and be accelerated. I would need to research this but all relevant articles I can google are behind pay walls. Must be a lucrative business this ionosphere .