World's First X-Ray Laser Goes Live 238
smolloy writes "The world's first X-ray laser (LCLS) has seen first light.
A Free Electron Laser (FEL) is based on the light that is emitted by accelerated electrons when they are forced to move in a curved path. The beam then interacts with this emitted light in order to excite coherent emission (much like in a regular laser); thus producing a very short, extremely bright, bunch of coherent X-ray photons. The engineering expertise that went into this machine is phenomenal — 'This is the most difficult light source that has ever been turned on,' said LCLS Construction Project Director John Galayda. 'It's on the boundary between the impossible and possible, and within two hours of start-up these guys had it right on.' — and the benefits to the applied sciences from research using this light can be expected to be enormous: 'For some disciplines, this tool will be as important to the future as the microscope has been to the past,' said SLAC Director Persis Drell."
Awesome (Score:5, Informative)
I had the pleasure of taking a tour of the Advanced Photon Source at Argonne National Labs. They have a similar setup; using accelerated electrons to produce x-rays, the real achievement here is the coherency part. I wonder how this effects high speed x-ray crystallography, is it easier to decode the scatter if the light is coherent? Will we be getting real time videos of enzymes in action? If so I can only imagine what that will do for chemical and pharmaceutical research.
A big medical breakthrough. (Score:5, Informative)
Re:The one question we all want to know. (Score:3, Informative)
Re:The one question we all want to know. (Score:2, Informative)
Yes indeed! You will become Atom Man! Your special power will be that you can turn yourself into a cloud of separate atoms, each disconnected from the other!
(Note: This does not mean that the laser will help you turn back.)
Re:First? (Score:1, Informative)
It's not the first - it's the most powerful and it is "hard" X-ray. The article itself does not make the claim of the "first", nor the wikipedia article linked in the summary.
Re:A big medical breakthrough. (Score:5, Informative)
As far as medical radiology goes, a pencil-thin beam would be nice for added precision, but also for dramatically reducing the radiation dose. My local hospital has stopped giving me CT scans because I've had so many in the past (out of necessity) that they don't want to fry me any more than necessary.
Replacing the emitters in a CT scanner, which basically spray you with radiation and rely on carefully-placed sensors to create the line-of-sight they want, with a directed, low-power beam that only hits with radiation those cells that actually need it, will dramatically reduce the amount of radiation that patients receive.
World's *First* X-Ray Laser? I don't think so. (Score:3, Informative)
Re:The one question we all want to know. (Score:2, Informative)
sounds like he already has that power. Redundant!
Re:Awesome (Score:3, Informative)
"Will we be getting real time videos of enzymes in action?"
No, enzymes in action must be in solution and not locked into a regular crystalline lattice of the sort required to diffract X-rays of comparable wavelength with the spatially encoded information of said molecular structure which is necessary to do diffractometry.
Re:First? (Score:5, Informative)
To be fair, the Nike-Hercules missiles were among the last nuclear defenses intended to be employed. The first was to knock out air bases with nuclear strikes to prevent bombers from getting in the air in the first place. After that came air interception using missiles such as the AIR-2 Genie. Nuclear-tipped SAMs would attempt to intercept over the ocean or unpopulated territory where possible (the Nike-Hercules had a range of over 75 miles), and explode over populated territories only if nothing else worked.
Re:First? (Score:3, Informative)
Not the first. Maybe the first X-ray FEL (maybe) but not the first X-ray laser proper. The first X-ray lasers were created in nickel and samarium plasmas created by few ns long, multi Kj, UV light pulses of LLNL's Novette laser [wikipedia.org] (predecessor of the Nova laser [wikipedia.org]) in the early '80s [harvard.edu]. The work was probably done with SDI in mind.
Re:World's *First* X-Ray Laser? I don't think so. (Score:3, Informative)
It actually says Hard X-ray's
http://hesperia.gsfc.nasa.gov/sftheory/xray.htm [nasa.gov]
This announcement believe it or not has actually made my day. It will 100% spur innovation like the original Red Lasers did.
Re:Awesome (Score:3, Informative)
jebus you're right. unbelievable [arxiv.org].
Re:Awesome (Score:4, Informative)
IAAECXRPX (I am an ex-computational-x-ray-protein-crystallographer). Lasers a bit left wing, since we usually use anode sources for x-rays on the home source and synchotrons for MAD sets. However, if the laser has tight enough phases (60-degrees) and coherency this is not just big but HUGE. Currently, there are two difficult steps in PX: (1) crystallization; and (2) phasing. The first is becoming easier using automated screening and robots (although we are only at the beginning of this process, so probably still 5--10 years out). The second has been considered one of the outstanding problems in (at least) biology if not all of science. To put this in perspective, it was only a few years ago that just *finding* the structure (phasing) was enough to warrant a Nature or Science paper. Nowadays you're gonna need some function, too, but the phasing is still spectacularly hard. If these guys have really done this, and they're getting good power, this will be a watershed event for all of biology.
Re:Awesome (Score:5, Informative)
For part two, lasers produce monochromatic light. One technique for doing real-time x-ray crystallography involves using polychromatic x-rays. Normally you get a single, specific, monochromatic wavelength (, or at least close enough that for data processing you largely ignore everything else. The resulting diffraction pattern looks something like that seen on wikipedia's page [wikipedia.org]. That page and links are actually pretty good. However you can use a broader spectrum of x-rays and get a different diffraction pattern due to having different wavelengths of light hitting your protein crystal over the course of the exposure, or a Laue diffraction image [anl.gov] (ignore the color--computer added). Interpreting Laue diffraction's significantly harder because you also have to take into account that you have basically multiple different wavelengths of light producing multiple different, overlapping diffraction patterns. Unlike monochromatic diffraction patterns, which require exposure times of at least tenths of a second even at APS (or potentially hours on a weaker rotating anode x-ray source like at an individual lab), Laue diffraction can be measured in picoseconds--on the time scale of chemical reactions catalyzed by enzymes. A few groups have done time-resolved x-ray crystallography with reactions by building up series of Laue images. You can't do it for everything, though. Data processing problems aside you typically need a chemical reaction that can be triggered by light. Also, proteins frequently undergo structural reorientations during catalysis--the change will have to be small enough so that the packing of proteins in the crystal lattice will not be affected. Time-resolved x-ray crystallography using Laue diffraction is never going to be widely used, but the results can still be very exciting.
What these guys have in mind and how practical it is I don't know since I've somewhat shifted away from protein x-ray crystallography. I do remember going to a conference a few years ago where some guys wanted to use a single molecule to collect data on--by blasting the bajesus (that's a technical term) out of it with an extremely short, extremely massive burst of x-rays. They had the problem though of ripping off basically all of the electrons in the process, IIRC. Even at weak home rotating anode x-ray sources you still have to worry about radiation damaging your crystal (and affecting your resulting model of the protein), but blasting away all the electrons? That's like comparing a flyswatter and a tactical nuke.
Re:Awesome (Score:3, Informative)
Re:Bah, that's nothing...- MALWARE! (Score:5, Informative)
Re:Light (Score:1, Informative)
Re:The one question we all want to know. (Score:5, Informative)
DO NOT CLICK THAT LINK!!! - Malware! (Score:4, Informative)
It will fsck you up. Unless you're running linux - then it's just really annoying.
Re:A big medical breakthrough. (Score:4, Informative)
Re:First? (Score:3, Informative)
Well, storage rings can produce radiation with a large coherence volume (i.e. cut out the part you can use), such as at the cSAXS beamline at the SLS. What's unique about these lasers is the ultrashort, huge emission at dependable timing that they can deliver.
No, SDI did not collapse the Soviet Union (Score:5, Informative)
There are problems with this idea.
(1) Its justification after the fact. No credible proof has been provided that this was ever the plan: rather, the Soviet Union collapsed economically,
in a way unexpected by the CIA and the intelligence community, then the SDI folks say "See ? that was our Sekrit plan all along". If it was the
plan, it shouldn't have been a suprise.
(2) SDI didn't change soviet spending. They did practically no SDI work (in comparison to the US), and Soviet military spending didn't change.
Counter-measures to SDI are / were far cheaper than SDI itself: SDI meant spending billions on new tracking and laser developments to appear
credible (even if no-one involved believed it would work); countering it meant a few dummy balloons and chaff. It risked bankrupting the US
far before bankrupting the SU.
(3) Not only did Soviet spending not change, the CIA knew that it didn't change, and yet SDI continued. A very expensive, failed, policy was continued
in order to keep money flowing into certain companies. It was a pork barrel.
The soviet economic collapse was triggered by OPEC, not SDI. When Saudi Arabia et al opened stopcocks and flooded the world with cheap oil,
the Soviet export economy collapsed.
Re:not a true laser (Score:2, Informative)