Timeline for Does positronium have a stable crystalline phase?
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| May 28, 2022 at 1:02 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Jan 25, 2022 at 11:05 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Dec 14, 2021 at 16:46 | history | edited | Urb | CC BY-SA 4.0 |
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| Dec 14, 2021 at 15:06 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Dec 14, 2021 at 8:58 | comment | added | anna v | What about tunnelling, a number of works with electron tunneling in crystals come up in a search example ucsdnews.ucsd.edu/pressrelease/… | |
| Apr 7, 2021 at 1:05 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Mar 5, 2021 at 20:57 | answer | added | Thor | timeline score: 1 | |
| Jan 11, 2021 at 17:49 | history | edited | lurscher | CC BY-SA 4.0 |
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| Sep 17, 2012 at 19:38 | comment | added | lurscher | @Nathaniel, actually, i understood now your comment; it is not enought to easily separate the positrons from the hadrons, the goal is to not bring the hadrons at all with you, since if they are not contributing to the fuel energy density, they are contributing to dry weight | |
| Sep 17, 2012 at 19:15 | comment | added | lurscher | @annav, those picosecond figures are all for parapositronium decay rates (S=0), orthopositronium rates (S=1) are one thousand times higher | |
| Sep 17, 2012 at 18:54 | comment | added | anna v | found this cesr.fr/~pvb/astropositron/presentations_files/Nagashima.pdf . I find picoseconds experimentally measured. | |
| Sep 17, 2012 at 18:43 | comment | added | anna v | Has there been any experimental confirmation of any of this model? From 1997 to now is a long time in research. My feeling is that if there are other electrons around, as there will be from the rest of the atoms, an S state with the positron will have a high probability from sheer numbers. | |
| Sep 17, 2012 at 16:09 | comment | added | lurscher | also, it mentions that this positronium stable against low energy radiation. So the main enemy of the positronium will be the 1) wall 2) collisions with the positronium itself | |
| Sep 17, 2012 at 15:25 | comment | added | lurscher | @annav, in the first paper i linked, there are details regarding this. Basically, the are two circumstances where positronium lifetime will grow significantly; with a high n (Rydberg), the lifetime will grow as $n^3$. The second one is that with sufficient electric and magnetic fields, the ground state has a lifetime of several years | |
| Sep 17, 2012 at 15:19 | comment | added | anna v | My basic question has to do with the lifetime of the positronium in any level. The longest in the wiki article is microseconds. How could a useful energy device work with such small lifetimes? | |
| Sep 16, 2012 at 18:13 | comment | added | lurscher | thanks - and i didn't take it as criticism either, so no need to clarify.. i'm just trying to condense the thoughts in a single question and possibly branch out to subquestions, to abide to SO policies: like Ron Maimon, i prefer to throw ideas on SO than to rot in some blog. My hope is that people find this brief and incomplete summary of questions a motivation to study the problem on their own. | |
| Sep 16, 2012 at 18:01 | history | tweeted | twitter.com/#!/StackPhysics/status/247394767271518210 | ||
| Sep 16, 2012 at 17:48 | comment | added | N. Virgo | Sure - I wasn't criticising your question, just thinking out loud. | |
| Sep 16, 2012 at 17:47 | comment | added | lurscher | @Nathaniel that is a fair, more general question, but i am choosing to focus on pure positronium as a first approximation to the problem. | |
| Sep 16, 2012 at 17:45 | comment | added | N. Virgo | Ah ok, I see. But then, maybe the question shouldn't be (just) "how can we store positrons without hadrons?" but "how can we store positrons among hadrons in such a way that they can be easily separated?" | |
| Sep 16, 2012 at 17:36 | comment | added | lurscher | @Nathaniel, in that case, antihydrogen would do the job very well. Unless the ratio of hadron doping to lepton is below $10^3$ (the ratio between electron and neutron/proton mass) most of the fuel will still be hadronic, so you get the associated inefficiencies (but, who knows, maybe they are not as bad as i think they are) | |
| Sep 16, 2012 at 17:29 | comment | added | N. Virgo | Just an off-the-wall thought after reading this, but if positronium by itself doesn't have a stable crystalline phase, perhaps positrons, electrons and neutrons might be able to form some kind of stable configuration. Or perhaps there could be some molecules of normal matter that could stably (and neutrally) trap positrons somehow, which might allow a reasonable storage density. | |
| Sep 16, 2012 at 16:10 | history | edited | lurscher | CC BY-SA 3.0 |
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| Sep 16, 2012 at 15:30 | history | edited | lurscher | CC BY-SA 3.0 |
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| Sep 16, 2012 at 15:25 | history | edited | lurscher | CC BY-SA 3.0 |
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| Sep 16, 2012 at 15:17 | history | edited | lurscher | CC BY-SA 3.0 |
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| Sep 16, 2012 at 14:43 | history | edited | lurscher | CC BY-SA 3.0 |
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| Sep 16, 2012 at 7:04 | history | edited | lurscher | CC BY-SA 3.0 |
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| Sep 16, 2012 at 6:56 | history | edited | lurscher | CC BY-SA 3.0 |
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| Sep 15, 2012 at 20:00 | history | asked | lurscher | CC BY-SA 3.0 |