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Gamma Rays From Thunderclouds
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.
Just fling electrons at the blue planet where the electricity is, and see if you can hit the little dust-specks. Like billiards! Anyway, it's fun to know that each time there's a thunderstorm, and a random electron flies in from somewhere in the universe, you're getting bombarded with braking radiation. Although, considering that I'm doing experiments with X-rays in my garage, I probably shouldn't worry about that. :)
also, first post (if my calculations are correct).
http://pinopsida.com
Is that five or six months down the line, the Incredible Hulk will start controlling electricity.
Or possibly the fusion of deuterium/hydrogen in rain water by lightning?
I actually posted an article about this back in 2005. Lightning Fusion And Other Hot News
Letter To Iran
This is going to make the best James Bond movie ever.
Les Miserables Volume 1 now up with my reading of
Comment removed based on user account deletion
And neutrons will crash into other nuclei and there will be secondary fissions and fusions. Neither fission nor fusion is an entirely straight forward reaction with only one set of byproducts. Muon catalyzed fusion produces gamma rays directly.
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
Letter To Iran
I have chaired sessions at meetings of the American Geophysical Union where this topic was discussed - over ten years ago!
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.
There are ground based gamma ray detectors (Google). They don't detect the gamma rays directly, but rather the showers as the gamma rays interact with molecules in the atmosphere.
GLAST , 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 celestial sky, but they have such large fields of view that they can also simultaneously make observations of the Earth for at least some of the time.
A basic calculation indicates that as many as 0.7-3% of 10 MeV gammas could make it down from 2000 m. Put another way, any gamma headed for their detector will make it there about that percentage of the time. Starting with a high flux could mean that a significant number of gammas make it to the scintillators, which can trigger off of relatively small numbers of photons.
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.
The story so nice, they posted it twice. ... and still only 23 comments.
George Bush + Linux = "I will not let information get in the way of the fight against Windows"
It's really one of those jargon-related things that happen so often in physics. Your average physicist uses "intensity" in ways that make optical scientists rip their hair out, since in optics intensity has a very specific definition. In the same vein, radiation scientists reserve "gamma" to describe photons originating from nuclear processes. Physicists in other specializations generally just go by energy because gammas tend to be higher in energy than X-rays. It's not necessarily the case though.
I call shinanagans. If this was true there would be a whole lot more green people running around smashing things. Everyone knows that gamma rays = Hulk, its a proven scientific fact.
With 41 comments, I expected at least ONE Incredible Hulk reference.
You're all very bad nerds.
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.
It is braking news about radiation after all.
Yup. The cosmic ray usually isn't a photon, it's a particle of some type that slams into the atmosphere and turns into a bunch of other particles, which slam into the atmosphere some more and eventually turn into some sort of photon. That is opposed to the gamma ray which IS a photon.
If thunderclouds can accelerate radiation energy, how come I never heard of people died in places where there are lots of thuderstorm activities due to radiation overdose?
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.
A Japanese nuclear plant, cosmic rays, thunderclouds? What could possibly go wrong?
It must have been something you assimilated. . . .
HOLY CRAP... BREMSSTRAHLUNG PHOTONS from frikkin BASIC FLUFFY CLOUDS IN THE SKY. What's next, some goshdarned erenkov radiation being emitted from like, Innocent Little Bunny Rabbits?! Or like, some freaking Antideuterium Particles shooting out of Very Cute Baby Kittens ??
I can throw as many stones as I wish; my house is made of transparent aluminum.
Also, while 1GeV is a typical cosmic ray energy, they can go much much higher. The "Oh my god" particle had an energy of around 50 Joules. That's comprable to a well-hit tennisball, which is a whopping amount of energy for a subatomic particle.
Ionizing radiation is much like most other poisons in that dose is critical in determining subsequent health effects. You are--right now--not only being bombarded by tiny amounts of ionizing radiation from most things around you, but your body tissues themselves are releasing ionizing radiation: they contain completely natural but radioactive potassium-40. It is, however, a very, very low level of radiation.
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.
There is a suspected but yet unproven relation between cosmic rays and lightning. The theory is that when a cosmic particle strikes the atmophere, it ionises a path though the atmophere. This then provides a conduit for lightning.
F ARWorkshop_Apr07_HeinoFalcke.pdf
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
http://www.lofar.org/workshop/23Apr07_Monday02/LO
RogerWilco the Adventurous Janitor
I'm not sure if you're joking or not, so I'll reply anyways. From the paper:
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 this paper set up a detector that can. Presumably they chose to set it up at that particular plant so they could correlate their detailed observations with those from the plant's detectors.
C.) The research was conducted by the University of Tokyo and the Japanese Space Agency (and others). The effect is not unique to Japan, rather the work was done in Japan. And yes, Japan does have magic special super clouds, but they are licensed to the makers of the Final Fantasy series.
Lastly, the effect was first suggested in 1925, but hasn't been investigated much since. Again, it's not caused by the nuclear plant (the submitter wasn't very clear about that). The plant just happened to be a convenient laboratory.