and it got me thinking: How would the positrons behave if they were immediately introduced into an IEC fusor after being created by the laser/gold. I imagine this question could be answered differently given the presense of other forms of matter also inside the fusor.
1) in isolation: could high energy positron collisions result in any form of fusion with themselves (and in the process create what byproducts). Can a lepton only plasma even exist?
1.a: Could the positrons at high energy annihilate with any of the high energy electrons circulating around the magrid or would the energy differences be sufficient to avoid annihilation
2) in any of the fuel schemes DD, DT or pB11. Does the strong force apply to leptons or just hadrons? If it does apply, what products would be created by smashing the positron into any of the assorted fuels?
“We’ve detected far more anti-matter than anyone else has ever measured in a laser experiment,” said Hui Chen, a Livermore researcher who led the experiment. “We’ve demonstrated the creation of a significant number of positrons using a short-pulse laser.”
Chen and her colleagues used a short, ultra-intense laser to irradiate a millimeter-thick gold target. “Previously, we concentrated on making positrons using paper-thin targets,” said Scott Wilks, who designed and modeled the experiment using computer codes. “But recent simulations showed that millimeter-thick gold would produce far more positrons. We were very excited to see so many of them.”
Heh, I think that sorta sailed way over my head there David
I guess my question was more speculation meant to understand the nature of matter, and not so much how to get the positrons into the IEC environment and just assuming it could be done (for instance pulsing the laser at a gold film which is already inside one of the cusps to inject them straight into the magrid).
Since the positrons are positively charged, I had assumed they would behave somewhat like the ion fuel would , and, charged to high energy by the anode, start circulating inside the fusor thereby avoiding annihilation and becoming contained rather like the ion fuel avoids snagging up electrons and becoming neutral. Once inside, they would start smashing into eachother or the ion fuel.
EricF wrote:Heh, I think that sorta sailed way over my head there David :D
I guess my question was more speculation meant to understand the nature of matter, and not so much how to get the positrons into the IEC environment and just assuming it could be done (for instance pulsing the laser at a gold film which is already inside one of the cusps to inject them straight into the magrid).
Since the positrons are positively charged, I had assumed they would behave somewhat like the ion fuel would , and, charged to high energy by the anode, start circulating inside the fusor thereby avoiding annihilation and becoming contained rather like the ion fuel avoids snagging up electrons and becoming neutral. Once inside, they would start smashing into eachother or the ion fuel.
There are too many electrons in the BFR to allow the positrons to last long.
Engineering is the art of making what you want from what you can get at a profit.
There are too many electrons in the BFR to allow the positrons to last long.
Yes, their are.
So the question is, how many are their (positrons), how much energy does an electron/positron contribute, (What form does that energy take, anyway?) how much time to the destruction of all of the positrons and ultimately, what effect will this have on the Polywell plasma?
There are too many electrons in the BFR to allow the positrons to last long.
Yes, their are.
Not so sure about that. One of my favorite proposals (ca. 1988) for a tokamak diagnostic was to inject a few positrons and do tomography (like PET) on the annihilation gammas. It was claimed that very few of the positrons would annihilate in the plasma, so you would only see them when they come out and hit a wall (limiter or divertor). A rather global measurement, but interesting because the particles are light like electrons, but of the opposite charge, so some effects would be reversed. I don't believe any such thing was ever built.
There are too many electrons in the BFR to allow the positrons to last long.
Yes, their are.
Not so sure about that. One of my favorite proposals (ca. 1988) for a tokamak diagnostic was to inject a few positrons and do tomography (like PET) on the annihilation gammas. It was claimed that very few of the positrons would annihilate in the plasma, so you would only see them when they come out and hit a wall (limiter or divertor). A rather global measurement, but interesting because the particles are light like electrons, but of the opposite charge, so some effects would be reversed. I don't believe any such thing was ever built.
I think that the fact that the BFR is running slightly electron rich while Toks run neutral might alter that conclusion. Provided of course that the densities in the core of the BFR are any where near what is expected.
All we have to go on so far are conjectures based on ignorance. Not a happy place.
Engineering is the art of making what you want from what you can get at a profit.
In other threads the limit on an excess of one charge has been emphasized. In the Polywell I understand that ~ 1 ppm excess of electrons are tolorated. As such, the injection of positrons couldn't exceed this limit (you couldn't just flood the chamber with positrons, even if you could produce them without a huge penalty in energy costs. There would have to always be an excess of electrons to have a potential well. The positrons would act opposite to the electrons - they would be fast in the center and slow on the perifery (just like the pos. ions). This would cause more Bremsstrulung radiation. Also, they would increase any central potential anode effect. I don't see how they would decrease the coulomb barrier ( like megatively charge muons are supposed to). I don't know how long a positron would survive, but I'm guessing perhaps a few thousand passes based on what Dr Nebel said about alpha particles bouncing around a few thousand times without losing much knietic energy through collisions.
In otherwords I see alot of negatives, and no advantages.
Now, if you had someway of making positrons at an nergy cost less than what you would gain through annialation..... (free energy anyone). How much energy is pumped by the laser to produce the positrons? 10x the positrons energy, 100x, 1,000,000x?
When positrons meet electrons, they destroy one another, releasing a 2.2 Mev gamma ray. The whole point of the polywell design is to have an excess of electrons in the core, so that the positively charged protons and B11 nuclei are attracted to the high density core, smack into one another and fuse.
I guess what I'm wondering is, given the unique conditions in the BFR acting kinda like a particle accelerator (and pretending for a moment that the positrons dont simply annihilate with the circulating electrons):
The nuclear forces are kinda funny. With the nuclei at close distances, the strong force overcomes magnetic repulsion and of course results in fusion. With the positron and nuclei, would the 'spin' nuclear force overcome magnetic repulsion and result in the nuclei capturing the positron in the electron cloud?
The nuclear forces are kinda funny. With the nuclei at close distances, the strong force overcomes magnetic repulsion and of course results in fusion. With the positron and nuclei, would the 'spin' nuclear force overcome magnetic repulsion and result in the nuclei capturing the positron in the electron cloud?
Positron capture by a neutron is a possible weak interaction. Its the inverse reaction to proton radioactive decay. Positrons tend to get "eaten" by the electrons first though.
