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Gamma Rays From Thunderclouds
Posted by
kdawson
on Sun Aug 26, 2007 06:43 PM
from the deploy-the-tinfoil-helmets dept.
from the deploy-the-tinfoil-helmets dept.
KentuckyFC sends us a report of gamma rays detected at a Japanese nuclear plant, whose origin was thunderclouds high overhead (abstract, article PDF). The theory is that showers of electrons caused by cosmic rays, when they encounter the high electric fields present in thunderstorm clouds, can be accelerated to energies above 10 MeV and result in bremsstrahlung photons detectable on the ground.
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Nature's own linear accelerator! (Score:4, Funny)
I suspect that the biggest consequence of this (Score:2, Funny)
Re:I suspect that the biggest consequence of this (Score:5, Funny)
Parent
Or Lightning Fusing Hydrogen? (Score:5, Informative)
I actually posted an article about this back in 2005. Lightning Fusion And Other Hot News [slashdot.org]
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Not so simple (Score:5, Informative)
Our own star the Sun produces gamma rays from the PP-I fusion chain 4 1H 1 4He + 2 positrons + 2 neutrinos + 2 gamma rays The by-products provide the source of luminosity: * Positrons: anti-electrons (e+) - collide with electrons (e-) * Neutrinos: rapidly escape from the star * Gamma rays (photons): travel outwards through star interacting many times with atomic gas. Energy is also provided by the PP-II and PP-III chains
Parent
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Where's An Evil Overlord When You Need One? (Score:3, Funny)
Wow. That's some high energy Gamma Rays (Score:2, Interesting)
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GLAST [nasa.gov], is a new gamma-ray mission which will launch early next year and will have the capability to measure TGFs up to much higher energies -- so we will get to really understand the acceleration mechanism. Both instruments on GLAST are designed to observe the celes
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Correct me if I'm wrong, but don't we have NO way to detect electrons that don't strike normal matter? As in, if I send a stream of electrons 10 meters away from you in your spaceship, aren't you completely oblivious to what I did if I missed?
We also haven't detected one species splitting into two -- does th
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Correct me if I'm wrong, but don't we have NO way to detect electrons that don't strike normal matter? As in, if I send a stream of electrons 10 meters away from you in your spaceship, aren't you completely oblivious to what I did if I missed?
You are wrong. Electrons in magnetic fields radiate synchrotron radiation and wee know that the Solar system and the Milky Way is pervaded by magnetic fields.
I thought the atmosphere was opaque to gamma rays (Score:2)
Re:I thought the atmosphere was opaque to gamma ra (Score:2)
Apparently the border guards are having problems telling the difference between kitty litter and enrich uranium [nature.com]
Re:I thought the atmosphere was opaque to gamma ra (Score:3, Informative)
Some numbers (Score:4, Informative)
That having been said, 2000m is the lower end of the altitude range (as I understand it) for storm clouds, and my calculation assumed dry air at sea level. The attenuation of photons does go up pretty sharply as you get to energies less than 10 MeV, as well.
Parent
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This is new ????? (Score:2, Informative)
THe Stanford radio science group is very active in modelling runaway electron acceleration such as this. In addition to gamma rays, free neutrons can also be produced.
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In addition to gamma rays, free neutrons can also be produced.
If I order a couple cases, is there a shipping charge?
Popping light bulbs and flat batteries (Score:2)
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***Occam's Razor Unsheathed***
Keep them out of the drink!
***Occam's Razor Sheathed***
Bump that story! (Score:3, Funny)
Exactly (Score:2)
Sure. I was just going to say that.
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It is braking news about radiation after all.
Bull sh*t (Score:3, Funny)
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OK, so there will be no emo-Hulks. Good enough for me.
slashdot has failed me. (Score:4, Funny)
You're all very bad nerds.
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The post above yours has a hulk reference
Wait a minute... (Score:2)
Where have I seen this before? (Score:4, Funny)
Bremsstrahlung photons from clouds (Score:3, Funny)
So (Score:2)
Suspected relation (Score:5, Informative)
This is currently a hot research topic in particle physics and meteorology.
A professor in Nijmegen and a collegue of mine are studying this phenomena (Heino Falcke and Lars Bähren)
http://www.physorg.com/news4162.html [physorg.com]
http://www.lofar.org/workshop/23Apr07_Monday02/LO
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Depends on who you're talking to. (Score:5, Informative)
Parent
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The border between x-rays and gamma isnt defined by energy.
There are gamma decays with only a few 10s of keV (just take any mösbauer experiment), and there are
x-rays in the many 100keV range (Uranium K-line, High energy undulators at the higher electron energy synchrotrons like SPring8, ESRF or APS).
For that reason in the range between 10keV and 1MeV, to avoid confusion, stuff is usually named by how it is made.
Although to be fair, starting at multi-MeV, the disti
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Re:They are X-rays, not gamma rays (Score:5, Informative)
Parent
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Do two gammas at the exact same energy have any way to distinguish them based on their origin?
Re:Radiation Overdose? (Score:4, Informative)
The gamma rays were only detected because they were near a nuclear power plant. Presumably such plants have very sensitive radiation detection equipment, and the number of ACTUAL gamma ray photos is sufficiently low that only very sensitive equipment could actually notice them.
Parent
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Um, lightning?
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Um, lightning?
Interesting... I wonder, how much of the electrical discharge is actually released as photons? And what exactly is the process by which they harm the things they strike, so to speak... ? For some reason, I've never actually considered the process by which lightning makes light.
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Also, while 1GeV is a typical cosmic ray energy, they can go much much higher. The "Oh my god" particle [wikipedia.org] had an energy of around 50 Joules. That's comprable to a well-hit te
Re:Radiation Overdose? (Score:4, Insightful)
According to our best theories--which, to be honest, are not by any means set in stone--there is no absolutely safe lower threshold for radiation exposure IF you consider the chances for causing cancer and genetic effects. These are called "stochastic" radiation effects, because they are best described in terms of risk and probability and do not have definite thresholds. For acute radiation toxicity--vomiting, blistering, and so on--there are fairly well-defined threshold doses; these radiation sicknesses are called "deterministic" effects because we can safely say that, given a certain amount of damage, you have a certain (high) chance of acute radiation sickness. These latter effects are similar to other toxic substances, in that they are talked about in terms of doses that have some specific chance (say, 50% or 99%) of causing an effect.
The amount of radiation-induced damage caused by the gammas released by a thunderstorm is very likely to be well below the thresholds for deterministic effecs, which means that an average person has essentially no chance of developing acute radiation sickness from a thunderstorm. Exposure to low levels of radiation may increase your chance of developing cancer, but such an increase is naturally impossible to quantify.
Parent
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A.) This is regularly detected at multiple nuclear plants, but is not caused by them. It is serendipitous because the plants already the gamma-ray detectors for operational monitoring.
B.) Superlatives like "lowest levels of radiation" are seldom meaningful in science. The detectors would have a minimum level they can reliably sense. Also, they can't determine the direction or frequency of the photons. The team that authored th