First-of-its-Kind Hard X-ray Free-Electron Laser Images Intact Viruses

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First-of-its-Kind Hard X-ray Free-Electron Laser Images Intact Viruses

Posted by Roblimo on Wednesday February 9, 2011 @12:52AM from the hoping-to-make-viral-videos-before-long dept.

Zothecula writes "In a paper published in the current edition of Nature, an international team of scientists describe how they obtained the world's first single-shot images of intact viruses – a technology that could ultimately lead to moving video of molecules, viruses and live microbes. Another paper by the same team describes how they were also able to successfully utilize a new shortcut for determining the 3D structures of proteins. Both advances were achieved using the world's first hard X-ray free-electron laser – the Linac Coherent Light Source (LCLS) – which scientists hope could revolutionize the study of life."

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intact after X-ray? by faa · 2011-02-09 00:58 · Score: 2

"hard X-ray free-electron laser" - are the viruses realy intact after such a burst?
1. Re:intact after X-ray? by Rakshasa+Taisab · 2011-02-09 01:04 · Score: 2
  
  Who cares about what happens to them after the burst... Kinda like old erotic images; how old and wrinkly they are now doesn't matter.
  
  --
  - These characters were randomly selected.
2. Re:intact after X-ray? by jamesh · 2011-02-09 01:16 · Score: 4, Insightful
  
  Who cares about what happens to them after the burst
  While a movie of bursting viruses might be interesting, it won't be as scientifically useful as a movie of a virus that is (mostly) unaffected by having the movie taken of it.
  This sort of stuff is like determining where a basketball is by throwing tennis balls at it and seeing where they land. You can only throw a few before the basketball becomes so affected by the tennis balls that you don't know where it is anymore (or how fast it's moving)...
3. Re:intact after X-ray? by Gilmoure · 2011-02-09 02:47 · Score: 1
  
  Thank you for ruining my pr0n activities. There's no goggles for inner eye.
  
  --
  I drank what? -- Socrates
4. Re:intact after X-ray? by Java+Pimp · 2011-02-09 02:56 · Score: 1
  
  ...how old and wrinkly they are now doesn't matter.
  The images or the models in the images?
  
  --
  Ascalante: Your bride is over 3,000 years old.
  Kull: She told me she was 19!
5. Re:intact after X-ray? by somersault · 2011-02-09 03:59 · Score: 1
  
  I'm sure it would be possible to create an algorithm that could determine the path (ie velocity and speed at any point) the basketball has taken after a couple of positive hits by the tennis balls, if you know the exact initial velocity of the tennis balls, how long they take to land, and where they've landed. The first hit will affect the path of the ball, but you could account for that too. Unless you're also having to deal with other factors of course, like invisible obstacles or changing winds, though with enough tennis balls you could map all of that too..
  
  --
  which is totally what she said
6. Re:intact after X-ray? by joe_frisch · 2011-02-09 04:31 · Score: 1
  
  No, they are destroyed. The X-ray pulse is short enough (10s of femtoseconds) that an image is collected before the virus (or other target) has time to explode. This is the big advantage of the LCLS over conventional X-ray sources.
7. Re:intact after X-ray? by slick7 · 2011-02-09 05:31 · Score: 1
  
  "hard X-ray free-electron laser" - are the viruses realy intact after such a burst?
  BFD
  .There's nothing like re-inventing the wheel. Royal R. Rife invented a non-lethal microscope way back in the 30's. However, just like Tesla, Farnsworth, Reich; Rife was ostracized by the peer community (read the corrupt medical and pharmaceutical organizations).
  
  --
  The mind conceives, the body achieves, the spirit manifests.
8. Re:intact after X-ray? by trailerparkcassanova · 2011-02-09 10:03 · Score: 1
  
  No, the samples are destroyed. The magic is the intensity and shortness of the pulse allows an 'image' to be acquired before it is destroyed.
9. Re:intact after X-ray? by TheCouchPotatoFamine · 2011-02-09 11:38 · Score: 1
  
  not the right analogy. It's as if you threw 1000000 BB's at a cement truck and everyonce in a while, all 1000000 BB's will strike the truck at the right angle to bounce off and make an image. They send large numbers of cement trucks through the BB beam to get even one image, so it's not some math trick as much as "who cares what happens to the virus after you've already bounced all the BB's off of it [at once]".
  
  --
  CS majors know the time/space tradeoff, but they never get taught the 3rd, crucial, tradeoff of the set: comprehension!
Great Title by AMindLost · 2011-02-09 00:59 · Score: 2, Interesting

Just trying to get the title to make sense made my head hurt!
1. Re:Great Title by Linker3000 · 2011-02-09 01:13 · Score: 1
  
  Likewise - I'm whimpering in a corner.
  
  --
  AT&ROFLMAO
2. Re:Great Title by faa · 2011-02-09 01:23 · Score: 1
  
  physicists love sophisticated titles
3. Re:Great Title by mooingyak · 2011-02-09 01:54 · Score: 4, Funny
  
  I-just wanted to Hard free-comment on-this-story with intact-hyphens.
  
  --
  William of Ockham had no beard. The most likely explanation is that it was chewed off by squirrels every morning.
4. Re:Great Title by kent_eh · 2011-02-09 04:13 · Score: 1
  
  Just like computer nerds love obfuscated ones...
  
  Buy, yes, I also found the title very hard to parse.
  
  --
  
  ---
  "I can't complain, but sometimes still do..." Joe Walsh
5. Re:Great Title by sorak · 2011-02-09 07:04 · Score: 1
  
  I honestly thought this was going to be an article about buzzwords.
Link by Monkey-Man2000 · 2011-02-09 01:02 · Score: 4, Informative

How about a link to the paper?

--
This post was generated by a Cadre of Uber Monkeys for Monkey-Man2000 (603495).
1. Re:Link by faa · 2011-02-09 01:06 · Score: 2
  
  oh, now that's been clarified
nothing exciting here by eyenot · 2011-02-09 01:03 · Score: -1

[quote] "In the second experiment, the team used no nanocrystals at all, instead spraying mimivirus particles through the beam â" mimivirus is the worldâ(TM)s largest known virus, and it infects amoebas. While hundreds of viruses were hit by the beam, only two of them provided enough data for reconstitution of their images" [/unquote]
First of all, the picture of the mimivirus, this huge honking virus, is a black dot surrounded by a psychedelic laser field herngh gnarly. But that's the best picture they can get of the largest virus known to mankind? A Grateful Dead poster? And second of all, that's the best picture they got out of hundreds of trials using different viruses? Two viruses show up in this thing's lizard peripheral vision and the headline brought to us at /. is "LASER IMAGES INTACT VIRUSES!" Technically not extremely misleading: "TWO IS STILL PLURAL!" "LIGHT STILL VISIBLE THUSLY IT'S AN IMAGE!" "BIG NEWS!"

--
"Stratigraphically the origin of agriculture and thermonuclear destruction will appear essentially simultaneous" -- Lee
1. Re:nothing exciting here by faa · 2011-02-09 01:44 · Score: 1
  
  actually this will allow more, i think. The virus image is kinda proof of concept
2. Re:nothing exciting here by gilleain · 2011-02-09 01:51 · Score: 1
  
  First of all, the picture of the mimivirus, this huge honking virus, is a black dot surrounded by a psychedelic laser field herngh gnarly. But that's the best picture they can get of the largest virus known to mankind? A Grateful Dead poster?
  
  That's the diffraction pattern. The paper has more meaningful images after "iterative phase retrieval with the Hawk software package". Hawk is open source, apparently:
  Link to Hawk software abstract in J. App Cryst
  also, they used some algorithm known as RAAR (Relaxed averaged alternating reflections). Heh, good name :)
3. Re:nothing exciting here by chudnall · 2011-02-09 03:21 · Score: 3, Funny
  
  But that's the best picture they can get of the largest virus known to mankind?
  That's just the first part. Then they send it over to the CSI guys and say "enhance!"
  
  --
  Disclaimer: Evolution comes with NO WARRANTY, except for the IMPLIED WARRANTY of FITNESS FOR A PARTICULAR PURPOSE.
So... by ikkonoishi · 2011-02-09 01:07 · Score: 1, Funny

How long until the TSA insists on having these?
1. Re:So... by roman_mir · 2011-02-09 01:13 · Score: 1
  
  so they can figure out if the microbes on you are not radical terrorists and are politically acceptable?
  
  --
  You can't handle the truth.
2. Re:So... by Zocalo · 2011-02-09 01:43 · Score: 1
  
  It'll still only be a stop-gap solution for the TSA. I doubt that they're going to be satisfied until they are able to image these "free radicals" that the chemists keep talking about.
  
  --
  UNIX? They're not even circumcised! Savages!
3. Re:So... by dfsmith · 2011-02-09 09:27 · Score: 1
  
  It would certainly solve nearly all air transport passenger problems; given that the beam vaporizes its sample.
moving video? by louic · 2011-02-09 01:12 · Score: 1

Is that like a usb stick with wheels, or does sending the video over the ethernet also count as "moving".
1. Re:moving video? by Anonymous Coward · 2011-02-09 01:22 · Score: 0
  
  I think they actually mean footage of them changing dwellings.
Simple answer: No. by YuppieScum · 2011-02-09 01:23 · Score: 3, Informative

FTFA:

The duration of its individual pulses is incredibly short – a few millionths of a billionth of a second. That’s still long enough to cause its subjects to vaporize , but that doesn’t happen until after their pictures have been snapped.
OK, this was in the second paragraph, but even so...

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1. Re:Simple answer: No. by PolygamousRanchKid+ · 2011-02-09 01:47 · Score: 5, Funny
  
  That’s still long enough to cause its subjects to vaporize , but that doesn’t happen until after their pictures have been snapped.
  So that means that the TSA will not be using hard X-rays . . . um, doesn't it?
  
  --
  Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
2. Re:Simple answer: No. by gilleain · 2011-02-09 01:55 · Score: 1
  
  Furthermore, from the Nature paper :
  
  We see no measurable sample deterioration. With the X-ray pulses used in this study, the explosion of micrometre-sized objects is hydrodynamic and the sample burns from the outside inwards, rarefying and destroying outer contours first. Trapped electrons move inwards to neutralize an increasingly positive core, and leave behind a positively charged outer layer, which then peels off over some picoseconds.
  Sounds painful.
3. Re:Simple answer: No. by AmiMoJo · 2011-02-09 03:06 · Score: 1
  
  Do they even use normal x-rays on people? Luggage, sure, but people?
  
  --
  const int one = 65536; (Silvermoon, Texture.cs)
  SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
4. Re:Simple answer: No. by Gilmoure · 2011-02-09 03:16 · Score: 1
  
  Do you want to be secure or do you hate America?
  
  --
  I drank what? -- Socrates
5. Re:Simple answer: No. by Defenestrar · 2011-02-09 04:12 · Score: 3, Informative
  
  You mean "normal" X-rays which is defined as the electromagnetic spectrum between 10 and 10,000 pm? As opposed to the backscatter X-rays which could range anywhere in the electromagnetic spectrum between 10 and 10,000 pm? Attenuation (transmission) and backscatter are different techniques for X-ray imaging - but they both still use X-rays. It's like the difference of looking at a stain glass window from the inside or the outside of the church - in both cases it's sunlight that does the illumination.
  It does get more complicated when you talk about specific wavelength, intensity, and etc... when you try to measure dosage. But all X-ray methods utilize ionizing radiation which is carcinogenic. Dose may be a very small portion of what you get every day, or in the case of the X-ray laser here, it may be enough to vaporize you.
6. Re:Simple answer: No. by slick7 · 2011-02-09 05:33 · Score: 1
  
  That’s still long enough to cause its subjects to vaporize , but that doesn’t happen until after their pictures have been snapped.
  So that means that the TSA will not be using hard X-rays . . . um, doesn't it?
  Maybe on J. Assange.
  
  --
  The mind conceives, the body achieves, the spirit manifests.
7. Re:Simple answer: No. by slick7 · 2011-02-09 05:34 · Score: 1
  
  Do you want to be secure or do you hate America?
  Think of the children!
  
  --
  The mind conceives, the body achieves, the spirit manifests.
8. Re:Simple answer: No. by Gilmoure · 2011-02-09 06:32 · Score: 1
  
  Hard X-rayed children are crunchy!
  
  --
  I drank what? -- Socrates
pics or STFU by quakemeister · 2011-02-09 01:27 · Score: 1

pics or it didnt happen
Worth a Nobelprize by Anonymous Coward · 2011-02-09 01:30 · Score: 1

and nobody here seems to understand the importance.
1. Re:Worth a Nobelprize by oodaloop · 2011-02-09 01:49 · Score: 3, Funny
  
  No way. This doesn't begin to compare to what Obama did in the first two weeks of his presidency.
  
  --
  Tic-Tac-Toe, Global Thermonuclear War, and relationships all have the same winning move.
2. Re:Worth a Nobelprize by Anonymous Coward · 2011-02-09 01:57 · Score: 0
  
  On the contrary, this will allow us to see how much money we have left once he leaves office. I say give these chaps the prize, or at least an Honorable Mention.
3. Re:Worth a Nobelprize by Anonymous Coward · 2011-02-09 02:46 · Score: 0
  
  man, you must really suck great big greasy donkey balls if some guy gets the Nobel prize just for not being you!
Yeah by Anonymous Coward · 2011-02-09 01:48 · Score: -1

But does it run Crysis?
Video? by Jedi1USA · 2011-02-09 01:50 · Score: 2

How would this lead to moving video when the subject matter is vaporized in the process?

--
My old sig was REALLY stoopid.
1. Re:Video? by Linker3000 · 2011-02-09 03:04 · Score: 1
  
  They run, but they can't hide.
  
  --
  AT&ROFLMAO
2. Re:Video? by leuk_he · 2011-02-09 03:16 · Score: 1
  
  Seen the movie tron? It is exactly like this, but on a virus scale,without the bikes. You get a exact digital image after the subject is vaporized.
LCLs? by Anonymous Coward · 2011-02-09 01:55 · Score: 0

Oh shit, first it's viruses, then it's japan having to save the world with giant robots.
"Laser", but not really by Mt._Honkey · 2011-02-09 01:57 · Score: 4, Informative

I am a physicist-in-training (grad student), and when I first heard of "free electron lasers" I was extremely impressed, because getting electrons into a multi-keV energy state that can lase without atoms involved sounded nearly impossible. Turns out it is, because these are not actually "lasers" the sense of Light Amplification by Stimulated Emission of Radiation. There is no population inversion as in real lasers.
The name of this specific FEL, the "Linac Coherent Light Source", is a much more correct name. They shoot electrons through a wiggler, and as they wiggle they emit coherent photons. Coherency is they key property of laser light, but the name refers to the method of light creation more than the actual output. I don't know why the x-ray community has felt the need to use this misleading name.

--

Don't Bogart the fish sticks
1. Re:"Laser", but not really by Anonymous Coward · 2011-02-09 02:15 · Score: 0
  
  Because it produces a similar light and leads to similar (in principle, but practically more powerful) applications.
  The term free electron laser is now used since decades and nobody is mistaken about the fact that it is not an actual laser.
2. Re:"Laser", but not really by Anonymous Coward · 2011-02-09 02:17 · Score: 0
  
  Um....OK
3. Re:"Laser", but not really by Anonymous Coward · 2011-02-09 02:39 · Score: 2, Informative
  
  Not only that, a Free electron laser (FEL) is only spatially coherent, not temporally coherent. This is a drawback of the "single-pass" method of X-Ray generation in FELs. Essentially, you can compare a FEL to amplified spontaneous emission (ASE) that is common in devices like superluminescent diodes. The bunching of electrons in FELs along the wiggler leads to different bunches that emit temporally coherent X-Rays, but across the entire FEL there are a large number of such bunches resulting in a spectral output that consists of a wide range of x-ray energies with many peaks overlayed on top.
  There isn't any temporally coherent X-Ray laser to date. People have proposed using very pure diamond crystals as X-Ray mirrors to set up a feedback cavity to a FEL, thus allowing for true temporal coherence just as in the case of traditional lasers that rely on a feedback cavity to establish temporal coherence. There are also some more esoteric proposals involving using a coherent "seed" laser, to seed the FEL oscillations, but it involves using 500+ order harmonics via non-linear effects.
  For the curious (and those with access to Nature) - this is a very nice, informative review on FELs: http://www.nature.com/nphoton/journal/v4/n12/abs/nphoton.2010.239.html
4. Re:"Laser", but not really by kindbud · 2011-02-09 02:45 · Score: 2
  
  Because the word "laser" has taken on a broader meaning since it was coined, so that it is used to refer generically to any coherent electromagnetic wave generating device or phenomena. Laser is the Kleenex of physics.
  
  --
  Edith Keeler Must Die
5. Re:"Laser", but not really by Anonymous Coward · 2011-02-09 02:46 · Score: 0
  
  I know a lot of disappointed sharks because they were looking forward to the upgrade.
6. Re:"Laser", but not really by supergumby · 2011-02-09 03:41 · Score: 1
  
  This is a great post. I was not aware that FELs are only spatially coherent due to bunching. I was under the impression they were also temporally coherent.
7. Re:"Laser", but not really by Gunnut1124 · 2011-02-09 04:03 · Score: 1
  
  "wiggler"
  
  I love the technical jargon.
  
  --
  America is all about speed. Hot, nasty, badass speed. -Eleanor Roosevelt, 1936
8. Re:"Laser", but not really by Anonymous Coward · 2011-02-09 04:28 · Score: 0
  
  Free Electron Light Amplification by Stimulated Emission of Radiation?
9. Re:"Laser", but not really by joe_frisch · 2011-02-09 04:39 · Score: 2
  
  In a conventional laser you have a laser rod and mirrors. You charge the rod and it starts to emit spontaneous light. That light is reflected from the mirrors and passes through the rod many times, gaining energy from spontaneous emission each time. Eventually you extract the available energy in the rod and a partially coherent beam is emitted from one of the partially transparent mirrors.
  Now imagine that rather than use mirrors, you used a lot of rods is series. The effect would be the same, spontaneous emission from the first rod would be amplified in the downstream rods until it saturated. The light emitted would be very similar to the light from the rod and mirror system.
  The LCLS (and other SASE FELs) work the same way - there are many undulators (33 for us) and the X-rays from the first undulator are amplified as they travel through the later undulators. The LCLS has 20-30 exponential gain lengths so the amplification finally saturates.
  You are right that it is not longitudinally coherent, but that is true of many lasers. Various techniques are used in conventional lasers to make they fully coherent. Similar tricks (seeding) will be added to the LCLS in the near future. We will probably do the first tests of seeded longitudinally coherent operation later this year.
  Also, when we run with very short pulses (few femtoseconds) the beam is nearly longitudinally coherent (due to transform limit).
  ---- Joe Frisch
  SLAC / LCLS
10. Re:"Laser", but not really by garyebickford · 2011-02-09 06:15 · Score: 1
  
  IANA physicist ... I'd like to disagree on the semantics of your point, although you could be right. While the method of stimulation is different from 'traditional' lasers, I would argue that Stimulated Emission of Radiation is still what occurs. I don't see anywhere that requires the population inversion to be a part of the definition - inversion is one of hypothetically many methods. So to my mind, that has only to do with the specific mechanism of lasing, rather than whether it is a laser.
  But this is a fine point, and might even be argued differently in different scientific disciplines. Of course, the difference between the core physics terminology and common usage means that your cause is hopeless. :) For most people, "If it walks like a duck and quacks like a duck", it's a laser for any common English definition and purpose, which is based on its effects and use, not on the details of construction.
  WIkipedia seems to stand on the side of calling it a laser, probably because it is a common language resource (Wikipedia not a 'scientific' source, but good enough for a start):
  
  A free-electron laser, or FEL, is a laser that shares the same optical properties as conventional lasers such as emitting a beam consisting of coherent electromagnetic radiation which can reach high power, but which uses some very different operating principles to form the beam. Unlike gas, liquid, or solid-state lasers such as diode lasers, in which electrons are excited in bound atomic or molecular states, FELs use a relativistic electron beam as the lasing medium which moves freely through a magnetic structure, hence the term free electron.[1] The free-electron laser has the widest frequency range of any laser type, and can be widely tunable,[2] currently ranging in wavelength from microwaves, through terahertz radiation and infrared, to the visible spectrum, to ultraviolet, to X-rays.[3]
  
  --
  It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
11. Re:"Laser", but not really by sjames · 2011-02-09 07:59 · Score: 1
  
  Since it's xrays, it wouldn't really be Light Amplification anyway but it's hard to pronounce XASER or XRASER. As with many things, the definitions change. LASER (correctly in all caps, rarely done these days) is literally Light Amplification by Stimulated Emission of Radiation (I know you know that!). However, the important aspect is not how it actually works, but the qualities of the EM output. That is coherent and well columnated. So the word laser (as opposed to the acronym LASER) now means a device that emits coherent and (usually) well columnated EM. So this device is a laser but not a LASER. A bit confusing but so it goes with human languages.
12. Re:"Laser", but not really by Anonymous Coward · 2011-02-09 11:33 · Score: 0
  
  old scientist here- scientifically inaccurate name changes get you on slashdot, son.
  just sit back, read the comments, and chuckle. the science is in the journals when you need it.
13. Re:"Laser", but not really by Mt._Honkey · 2011-02-09 13:58 · Score: 1
  
  Thanks for the comment.
  "Stimulated emission" has a specific meaning in physics: an electron (or in theory some other charged particle) is in an excited state, and a photon passing by causes that electron to drop down to a lower energy level and emit a photon of its own. In the case of the FEL we're certainly doing something to the electrons to make them emit photons, but it's not "stimulated emission" in the correct sense.
  The nature of stimulated emission is what requires population inversion or something else similar. Population inversion just refers to getting all the electrons in the system up into that excited state. Perhaps you don't have to go to the extreme, but the point is you get the electrons to store up energy, then de-excite them by passing photons nearby.
  Unfortunately the true nature of FEL's isn't universally known outside of the x-ray field. I'm a nuclear physicist and went to a talk on FELs and what they can do for nuclear physics, and afterwards about half the physicists I talked to from the audience didn't know, even after the talk, exactly how the FELs worked. The name "laser" gave them pre-conceptions about the fundamental principles that must govern the FEL so that when the description of its operation came all that was left was confusion.
  I also looked at that wikipedia article before making my previous post. It seems okay for wikipedia, but am considering making a note on the page about this. I may want to consult with laser experts first though. Maybe that's why I posted on slashdot instead.
  
  --
  
  Don't Bogart the fish sticks
14. Re:"Laser", but not really by Mt._Honkey · 2011-02-09 14:11 · Score: 1
  
  Very useful post, but it doesn't address my concern. The geometry and coherency are not the issue, it is the stimulated emission. I believe your description of a traditional laser is not quite right: once the initial spontaneous light starts passing through the rod it induces stimulated emission from the other electrons. It is true that mirrors are not necessary, as in the NIF system for example.
  As I understand it the electrons going through the undulators are not undergoing stimulated emission, but are emitting synchrotron radiation as they are accelerated by the undulator's magnetic field. If the electrons are bunched they emit in phase and thus the light is coherent. You're saying that somehow the previously emitted photons stimulate emission from other electrons? What energy do the electrons have that they can emit in stimulated emission? I don't see how it can be their kinetic energy because that would violate conservation of momentum.
  Please do explain, because if I'm wrong I'd be quite fascinated to learn what's really going on.
  
  --
  
  Don't Bogart the fish sticks
15. Re:"Laser", but not really by garyebickford · 2011-02-09 14:30 · Score: 1
  
  Interesting, thanks. So is that why they are tunable? As I understand it, in the 'normal' state, electrons can only emit photons of a certain frequency according to the difference in energy between the excited state and the lower or ground state. So all the light comes out at that frequency. And if I understand what you are saying, the 'wiggler' is shoving the electrons back and forth, and the electrons are emitting energy - as a result of the change in momentum? Or from an interaction between the electron and the surrounding electric field? I'm not clear on how/why the electrons are emitting anything.
  
  --
  It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
16. Re:"Laser", but not really by joe_frisch · 2011-02-09 17:40 · Score: 1
  
  The original description of a Free Electron Laser by John Madey (in the 70s I think) was entirely quantum-mechanical. This description while correct, is also very complicated (I've been working on FELs on and off since the mid 1980s and I'm afraid all I can do is suggest that you read the papers - I don't understand them). I know that if you look at the electron in the combined field of the undulator and the propagating radiation, a QM description looks just like stimulated emission. I know this is a cop-out on my part, but I really don't understand the physics.
  The reason I (and most FEL people) don't understand the quantum description is that there is a much simpler classical description (by Colson?) that predicts the same results for all existing FELs. (for a very high energy FEL you would need a quantum description, but no existing or planned machines operate in the regime). This classical description (which it sounds like you have heard ) is used for essentially all FEL work.
  BTW: there isn't a conservation of momentum problem because the electrons are interacting with the strong undulator field and that can absorb momentum (and transfer it to the physical magnets). The energy comes from the initial kinetic energy of the electrons which slow down (or more precisely lose energy, since they are ultra-relativistic) during the interaction.
  In a classical sense, the input radiation causes the electrons to bunch, an those bunches can then emit coherently. For small amounts of bunching this process is linear and looks just like the gain from stimulated emission.
  Sorry I can't give a better physics description - I should make another try at the original papers.
  --- Joe Frisch
17. Re:"Laser", but not really by Mt._Honkey · 2011-02-10 01:49 · Score: 1
  
  Thanks!
  
  --
  
  Don't Bogart the fish sticks
Wait, is this spam? by Anonymous Coward · 2011-02-09 01:58 · Score: 0

"First-of-its-Kind Hard X-ray Free-Electron Laser Images Intact Viruses"? I get dozens of emails like this every week. They are usually caught by my spam filter, though.
Video from Stanford onn LCLS by failedlogic · 2011-02-09 02:01 · Score: 4, Informative

Here's a video (animation) from Stanford explaining how the LCLC works.
http://lcls.slac.stanford.edu/AnimationViewLCLS.aspx
1. Re:Video from Stanford onn LCLS by Anonymous Coward · 2011-02-09 04:53 · Score: 0
  
  This link should have been included in the summary. I wonder what the far end of that tube looks like after a few days of operation.
2. Re:Video from Stanford onn LCLS by Anonymous Coward · 2011-02-09 06:13 · Score: 0
  
  What the hell is wrong with the audio in that video?
Actually... by YuppieScum · 2011-02-09 03:13 · Score: 1

...it sounds like a fast version of using a sun-bed.

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ESS by jcgam69 · 2011-02-09 03:32 · Score: 1

This proposed neutron "microscope" could image the individual atoms of the virus: http://www.ess-neutrons.org/
1. Re:ESS by Dr.Dubious+DDQ · 2011-02-09 04:10 · Score: 1
  
  I have an old (1940's) Microbiology book that mentions a "Proton Microscope" which was evidently invented in France about that time, too.
  From what I can tell, they are still sometimes used for metallurgical studies of some kind, but nothing else. I guess although the really small wavelength means you can hypothetically get amazingly high-resolution images, actually getting the beam to focus is extremely technically difficult.
  Or at least that what I remember from when I went and looked it up.
  
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Study of life? by mr100percent · 2011-02-09 04:08 · Score: 1

I know it will cause a biologist flamewar, but can we describe studying viruses as "studying life" when it's arguable whether viruses are alive or not?
1. Re:Study of life? by Danse · 2011-02-09 04:37 · Score: 1
  
  I know it will cause a biologist flamewar, but can we describe studying viruses as "studying life" when it's arguable whether viruses are alive or not?
  Did you miss the part that noted that viruses aren't the only things they can study with this tool?
  
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2. Re:Study of life? by mr100percent · 2011-02-09 04:48 · Score: 1
  
  I didn't miss it, but thought it an interesting point to go over.
3. Re:Study of life? by blair1q · 2011-02-09 06:17 · Score: 1
  
  Life has many meanings. Cells are alive. People are alive. People are made of cells. So are you still alive when your brain and heart have been destroyted but your toenails are still growing?
  So if a virus, which needs you to "live", isn't alive when it's in you, are the cells that produce your toenails ever alive?
4. Re:Study of life? by Locke2005 · 2011-02-09 06:24 · Score: 1
  
  I define "life" as anything that disobeys the second law of thermodynamics. Viruses are not only alive, they play an important role in driving evolution.
  
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  I've abandoned my search for truth; now I'm just looking for some useful delusions.
5. Re:Study of life? by 246o1 · 2011-02-09 07:00 · Score: 1
  
  Toenails don't keep growing - your flesh shrinks, exposing more of them.
  
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  Although the moon is smaller than the earth, it is farther away.
6. Re:Study of life? by blair1q · 2011-02-09 07:55 · Score: 1
  
  Actually, I knew that, and forgot.
  So were the cells that make your toenails ever really alive?
Plasma Recombination Laser is Cheaper by Anonymous Coward · 2011-02-09 05:46 · Score: 0

I have been following the field for several decades now and this is a significant milestone in holographic imaging of single bio-molecules and more complex structures, however the same results could be achieved with the infinitely cheaper desktop plasma recombination laser. In plasma lasers, amplified spontaneous emission is achieved by population inversion between two quantum states via rapid cooling and subsequent three-body recombination overpopulation of upper state and rapid radiative depletion of lower state. More research needs to be done on rapid cooling of highly ionized atoms before plasma lasers become available and affordable for most Universities.
John Talbot, Research Associate, University of Ottawa
Should diffraction be called "imaging"? by asadodetira · 2011-02-09 05:52 · Score: 2

They are not obtaining images but diffraction patterns, which after applying sophisticated methods lets them reconstruct a configuration that is consistent with the diffraction image, to within some margin of error. This techniques tend to better for confirming proposed structures that to getting it from scratch.
Kind of cherry-picking your achievement there by blair1q · 2011-02-09 06:01 · Score: 1

I had to read the headline about six times to figure out what it meant.
Now I'm going to go have a first-of-it's-kind lunch of whatever combination of items they have in the cafeteria arranged in a particular way on the tray with just that much salt and ketchup on it...
1. Re:Kind of cherry-picking your achievement there by joe_frisch · 2011-02-09 12:12 · Score: 1
  
  This has been a bit of a problem. The LCLS is 30X shorter wavelength, and maybe 100X higher power (depending on how you measure) than any previous X-ray laser but its really difficult to describe that without using all sorts of qualifiers. The single shot virus imaging (applicable to a wide range of nanometer scale objects) is far beyond the capabilities of any other system but again the need to apply all sorts of qualifiers makes it sound somewhat weak.
  Note - in claiming high power I'm not counting the non-published bomb-pumped laser work done by the military. There is a great deal of controversy over whether that worked - I've spoken to people on the project who have strongly hinted at either YES or NO, but the work is classified so there is no way to tell whether it worked, or if so, what sort of performance was seen.
Re:Should diffraction be called "imaging"? by Locke2005 · 2011-02-09 06:26 · Score: 1

If it can be used to generate an image, it's imaging. Many imaging methods use statistical techniques; I don't see how this is any different.

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I've abandoned my search for truth; now I'm just looking for some useful delusions.