Positronium

[MSimon]

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http://beforeitsnews.com/news/38/501/Fu ... cists.html

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[vernes]

Doesn´t gamma ray lasers open the possibility of molecular level detail scanning methodes?
Like, "counting number of neurons in a brain" detail?

[nextbigfuture]

http://nextbigfuture.com/2010/05/path-t ... nsate.html

The first annihilation laser will be made in the following steps:
1.Attain Bose-Einstein condensed (BEC) positronium.
2. Make a source capable of delivering 10^12 slow positron per second on a 1 mm target.
3.Develop a multiple trap for storing and releasing 10^13 positrons.
4. Observe stimulated annihilation.
5. Make 1J annihilation gamma ray laser pulses. [this one joule laser has to be scaled up about one million times to enable the nuclear fusion system described above]

A three year project to get through step 1 would proceed via the following tasks.
A. Year 1: Make a system for producing brightness enhanced 10 ns pulses of 10^7 5 keV positrons in a 10 micrometer diameter spot.
B. Year 1: Develop a method for making cavity structures in porous silica for containing BEC positronium.
C. Year 2: Make a BEC positronium target chamber with 4K cooling and optical access.
D. Year 3: Develop a laser system for detecting the BEC state via the disappearance of Doppler broadening.
E. Year 3: Characterize the positronium BEC by measuring the condensate fraction as a function of time, temperature and density.

3 years to a good positronium BEC and then a few more years to 1joule gamma ray laser and then years to scale to 500 kj gamma ray laser which can then be used for better nuclear fusion than regular lasers.

42 page air force project document
http://www.dtic.mil/cgi-bin/GetTRDoc?AD ... tTRDoc.pdf

24 page powerpoint from 2009
http://conferences.jlab.org/JPOS09/talk ... assidy.ppt

[Stoney3K]

Reading the article, it sounds like they're trying to use a jackhammer to carve a hammer, and hit a nail in the process.

Figure this: You have a bunch of positronium (anti-hydrogen, p- and e+) and you get it to annihilate with regular H2, so you produce gamma rays through annihilation. That's one of the purest forms of energy you can get -- and you use it to start up a fusion reaction?

In laments, Montgomery Scott terms, that's starting up the impulse engines with the warp reactor.

[MSimon]

Reading the article, it sounds like they're trying to use a jackhammer to carve a hammer, and hit a nail in the process.

Figure this: You have a bunch of positronium (anti-hydrogen, p- and e+) and you get it to annihilate with regular H2, so you produce gamma rays through annihilation. That's one of the purest forms of energy you can get -- and you use it to start up a fusion reaction?

In laments, Montgomery Scott terms, that's starting up the impulse engines with the warp reactor.

That was my impression. I like the way you expressed it.

[MirariNefas]

Doesn´t gamma ray lasers open the possibility of molecular level detail scanning methodes?
Like, "counting number of neurons in a brain" detail?

We can already image at molecular level detail. It's called the electron microscope. Also, neurons are a lot bigger than molecules, so we don't actually need electron microscopes to count them. The only problem is cutting slices of brain one cell thick to stick on slides beneath your microscope. Not sure why you'd really want to count them though.

[kunkmiester]

electron microscopes IIRC can't do molecular level imaging, but we do have a few that can, scannign tunneling microscopes among them. There's actually plans online for making STMs.

[JCee]

Doesn´t gamma ray lasers open the possibility of molecular level detail scanning methodes?
Like, "counting number of neurons in a brain" detail?

We can already image at molecular level detail. It's called the electron microscope. Also, neurons are a lot bigger than molecules, so we don't actually need electron microscopes to count them. The only problem is cutting slices of brain one cell thick to stick on slides beneath your microscope. Not sure why you'd really want to count them though.

Although electron microscopes can image a molecular levels they do have severe limitations (unless the technology has radically changed in the last 10 years).
1) Biological Samples must be fixed and treated with exotic compounds (such a gold) to be imaged in an electron microscope possibly resulting in artifacts.
2) Because of limitation 1) samples may not be imaged In Situ and in a functional living environment.
A gamma ray microscope could thus be potentially be useful for biological samples (actually an x-ray microscope could probably do just about everything a gamma ray microscope could do and probably would be easier to develop).

[vernes]

We can already image at molecular level detail. It's called the electron microscope. Also, neurons are a lot bigger than molecules, so we don't actually need electron microscopes to count them. The only problem is cutting slices of brain one cell thick to stick on slides beneath your microscope. Not sure why you'd really want to count them though.

Normal people cryogenicly freeze, nerds scan and store.
I understood a gamma laser would offer the possibility of a holographic scan of living tissue, at molecular detail.
So I'm always interested when the word "gamma ray laser" drops.

Digital data can be stored alot securer then a lump of dead brain.

[BenTC]

Digital data can be stored alot securer then a lump of dead brain.

After the upload faciities have been well tested over a few years - I do look forward to taking up my new hobby in base jumping.

[Stoney3K]

I understood a gamma laser would offer the possibility of a holographic scan of living tissue, at molecular detail.
So I'm always interested when the word "gamma ray laser" drops.

Digital data can be stored alot securer then a lump of dead brain.

I fail to see the method in which a gamma ray laser (high-energy ionising radiation) would be able to scan living tissue in a non-invasive manner.

AFAIK there is no type of tissue that can withstand even a small dose of gamma rays, let alone a coherent beam of gamma rays.

[JCee]

I agree there is little hope (no hope) for a gamma ray laser or xray laser microscope to scan tissue in a non destructive manner. However for laboratory research they would still be a great improvement over scanning tunneling electronmicroscopy, standard electron microscopy, and atomic force microscopy.

Advantages.
1) No Harsh pretreatment of biological samples with vapor deposition of gold
(kills the sample hours before imaging)

2) No exposing of the biological samples to harsh vacuums.

3) Laboratory biological samples may be imaged In Situ, in real time, and in real world conditions. (In the lab while not optimum to destroy your sample you can usually just slap another sample into place for further experiments)

Disadvantages
1) Destructive imaging of samples precludes use on a whole person. This is the same with all other current technologies used at the extremely small scale but you could imaged removed samples quicker, easier, and with less possibility of artifacts.

Not sure about the physics of it but reportedly metamaterials with negative refractive properties opens up the possibility of imaging objects smaller than their wavelength potentially greatly reducing the size of objects imaged with conventional light (gives me a headache just thinking about the physics)

[MirariNefas]

electron microscopes IIRC can't do molecular level imaging, but we do have a few that can, scannign tunneling microscopes among them. There's actually plans online for making STMs.

They can do molecular level. I've seen a cryoelectron microscope used to image phage coats. You can see individual tail fibers, and that wasn't the limit of the technology. STMs are pretty great though.

2) No exposing of the biological samples to harsh vacuums.

Heh, I used to image fruitfly eyes in an EM. Sometimes the vacuum would make their eyes implode (no, not explode). As their heads are like, half eyeball, seeing them with concave eyes is kinda funny. Sometimes they handled the vacuum pretty well though, and wiggled around after I pulled em out. It had me wanting to breed a line of vacuum resistant fly. Alas, we made them sit still in the scope by gluing them to a slide, and it's a bit hard to cross immobile flies.

By the way, we didn't have to treat these "samples" with gold. I guess that's only necessary at higher resolutions. Eye cells aren't exactly molecular level detail (though it is sufficient to count neurons, heh. Okay okay, I knew Vernes didn't actually want to count them).


Now, can someone explain why a gamma ray microscope would do holographic imaging? I don't care if it's destructive or not right now, as JCee said that's pretty standard for this scale anyway. I think the uploaders don't care either, as long as the process is precise enough to capture all relevant information. A more detailed, faster form of holographic imaging would be pretty nice, fried sample or no.

[Stoney3K]

Now, can someone explain why a gamma ray microscope would do holographic imaging? I don't care if it's destructive or not right now, as JCee said that's pretty standard for this scale anyway. I think the uploaders don't care either, as long as the process is precise enough to capture all relevant information. A more detailed, faster form of holographic imaging would be pretty nice, fried sample or no.

Because it's a gamma ray LASER.

It's coherent EM energy, so it's possible to do interferometry (holography) by shooting the sample with a reference beam.

[MirariNefas]

I don't get it. That lets you image the interior of an object somehow?