[meteorite-list] "Hotter Than Any Known Star"

[Pete Pete]

Good morning, all,

This item has got me thinking: I've read a few articles that in the past 
laboratories have attempted to create chondrules, but failed.

Is anyone on the List familiar with what was the major obstacle, and is it 
an endeavour that's still tried from time to time?

Cheers,
Pete


http://www.aip.org/enews/physnews/2006/split/767-3.html

Physics News Update

Number 767 #3, February 28, 2006 by Phil Schewe and Ben Stein

America's Hottest Lab

A temperature of 2 to 3 billion degrees Kelvin -- hotter than the interior 
of any known star -- has been achieved in a lab in New Mexico.

The temperature record was set recently in a test shot at the Z Pinch device 
at Sandia National Laboratory, where an immense amount of electrical charge 
is stored in a device called a Marx generator. Many capacitors in parallel 
are charged up and then suddenly switched into a series configuration, 
generating a voltage of 8 million volts. The process captured in a famous 
photograph, see Physics News Graphics.

This colossal electrical discharge constitutes a current of 20 million amps 
passing through a cylindrical array of wires, which implodes. The imploding 
material reaches the record high temperature and also emits a large amount 
of X-ray energy (see PNU 702).

Why the implosion process should be so hot, and why it generates X-rays so 
efficiently (10-15 percent of all electrical energy is turned into soft 
X-rays), has been a mystery.

Now Malcolm Haines of Imperial College, in London, and his colleagues, think 
they have an explanation. In the hot fireball formed after the jolt of 
electricity passes through, they believe, the powerful magnetic field sets 
in motion a myriad of tiny vortices (through instabilities in the plasma), 
which in turn are damped out by the viscosity of the plasma, which is made 
of ionized atoms.

In the space of only a few nanoseconds, a great deal of magnetic energy is 
converted into the thermal energy of the plasma. Last but not least, the hot 
ions transfer much energy to the relatively cool electrons, energy which is 
radiated away in the form of X-rays.

Haines et al., Physical Review Letters, 24 February 2006
Contact Malcolm Haines, m.haines at imperial.ac.uk
Image at Physics News Graphics

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