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.

Nature's own linear accelerator!

[atomicthumbs (824207)]

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).

I suspect that the biggest consequence of this

[The_mad_linguist (1019680)]

Is that five or six months down the line, the Incredible Hulk will start controlling electricity.

Re:I suspect that the biggest consequence of this

[Spudtrooper (1073512)]

It's getting cloudy. You wouldn't like me when it's cloudy.

Or Lightning Fusing Hydrogen?

[DumbSwede (521261)]

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 [slashdot.org]

Re:

[by Anonymous Coward]

Actually, fusion should produce fast neutrons, not gamma rays.

Not so simple

[DumbSwede (521261)]

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

Where's An Evil Overlord When You Need One?

[STrinity (723872)]

This is going to make the best James Bond movie ever.

Wow. That's some high energy Gamma Rays

[DrBuzzo (913503)]

I would be interested to find how often these sort of effects are observed. Getting energy levels up to 10 million electron volts is unusual in nature, with the exception of some cosmic rays. That level is higher than the binding energy of most elements. Thus, in theory, a gamma photon of such a high energy level could dislodge a neutron or possibly a proton from a nucleus. I would tend to think this sort of natural transmutation would be exceedingly rare, but it's still interesting, because it coul

I thought the atmosphere was opaque to gamma rays

[Beryllium Sphere(tm) (193358)]

The gamma ray observatories have to be in orbit. How is someone on the ground detecting gamma rays?

Re:I thought the atmosphere was opaque to gamma ra

[Ambitwistor (1041236)]

There are ground based gamma ray detectors (Google [google.com]). They don't detect the gamma rays directly, but rather the showers as the gamma rays interact with molecules in the atmosphere.

Some numbers

[Wilson_6500 (896824)]

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.

This is new ?????

[by Anonymous Coward]

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.

Bump that story!

[GISGEOLOGYGEEK (708023)]

The story so nice, they posted it twice. ... and still only 23 comments.

Bull sh*t

[riffzifnab (449869)]

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.

slashdot has failed me.

[J. T. MacLeod (111094)]

With 41 comments, I expected at least ONE Incredible Hulk reference.

You're all very bad nerds.

Where have I seen this before?

[fahrbot-bot (874524)]

A Japanese nuclear plant, cosmic rays, thunderclouds? What could possibly [wikipedia.org] go wrong?

Bremsstrahlung photons from clouds

[The Media Mechanic (1084283)]

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 ??

Suspected relation

[RogerWilco (99615)]

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.
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/LOF ARWorkshop_Apr07_HeinoFalcke.pdf [lofar.org]

Depends on who you're talking to.

[Wilson_6500 (896824)]

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.

Re:They are X-rays, not gamma rays

[ceoyoyo (59147)]

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.

Re:

[dbIII (701233)]

result in bremsstrahlung photons detectable on the ground.

It is braking news about radiation after all.

Re:Radiation Overdose?

[StrongAxe (713301)]

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.

Re:

[ZombieWomble (893157)]

Humans are much more tolerant to (relatively) small amounts of radiation than people often think. Depending on where you live, your average yearly dose can vary by almost a factor of 1,000 - the relative dose from such events in thunderstorms is much less than this variation in background, given how little is produced by any given event.

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?

[Wilson_6500 (896824)]

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.

Re:

[iamlucky13 (795185)]

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 th