Lightning Bolt X-Rays Imaged

X-rays filmed at an amazing 10,000 frames per second.  I think we want to use this at Focus Fusionto capture the plasmoid forming up if it can be done.  I suspect X-rays are blasted loose there.

The methodology will at least teach us something about thefine structure of a lightning bolt.

Here we already discover that lightning is emitted at orabout the tip of a bolt and not from the trailing plasma path.  This is not too surprising when one considershow we produce them in a tube by blasting electrons into a plate.

X-ray vision tracks lighting bursts

Dec 16, 2010

Blink and you've missed it. Researchers in the US havecaptured the world's first X-ray images of lightning, by creating a specialcamera that can capture radiation at 10 million frames per second. Theypresented their new findings at the American Geophysical Union (AGU) FallMeeting in San Franciscoand they say that this new view of lightning could help to solve some of themysteries of this spectacular natural phenomenon.

The research was carried out at the International Centerfor Lightning Research and Testing, located in Florida. It is one of the few sites in worldwhere lightning is initiated and studied under controlled conditions. By firingrockets with trailing wires into thunder clouds, scientists are able togenerate electric fields that are large enough to trigger bolts of lightning,which then propagate back down towards the rocket launch tower.

Joseph Dwyer and colleagues at the FloridaInstitute of Technology became interested in the fact that lightning emitsX-rays as it propagates through the air, a phenomenon that was only noted inthe past decade. But given that X-ray sources in lightning travel through theEarth's atmosphere at velocities approaching the speed of light, it isdifficult to catch them on camera before they disappear. In addition, theycannot be imaged with standard mirrors and lenses because huge amounts ofmaterial are required to prevent X-rays and gamma rays from entering throughthe sides of a camera.

Tried and true method

Dwyer's team has created a customized camera thathas 30 detectors made from a combination of sodium iodide and photomultipliertubes, each measuring 3 × 3 inch. The device, which isapproximately the size of a standard refrigerator, is also equipped with a3 inch pinhole aperture, and can record X-rays at 10 million frames per second."This is actually a very old technique for making images, like that seenin a camera obscura," Dwyer says.

We're seeing lightning as Superman would seeit with his X-ray vision Joseph Dwyer, Florida Institute of Technology

During July and August this year, Dwyer's teamstudied four rocket-triggered lightning flashes at the Florida test site. Each flash lasted forapproximately two seconds and the resulting sequences of images revealed thatX-rays emerged primarily from the vicinity of the lightning tip as itpropagated towards the Earth. As the lightning crashed into the control towerit also triggered large bursts of gamma radiation, which were also captured bythe camera.

"For the first time we're catching a glimpseof lightning in the X-ray emission," says Dwyer. "We're seeinglightning as Superman would see it with his X-ray vision".

Dwyer hopes that the images can help to explainhow bolts of lightning propagate through the air – a process that is stillpoorly understood. "When lightning propagates it moves in a halting mannercalled stepping. It will pause, then leap forward, pause, leap forward... Wedon't know how or why it chooses to do this," he says. "It isdifficult to come up with models to explain this motion, since we don't knowwhat the basic picture is, but the images really help. They tell us where thecharges are, where the high fields are and where the air is breakingdown."

Aboutthe author

James Dacey isa reporter for reports from the American Geophysical Union Fall Meeting in San Francisco

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