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X-ray Generator Fits In the Palm of Your Hand
ananyo writes "Scientists have reported the first tabletop source of ultra-short, laser-like pulses of low energy, or 'soft,' X-rays. The light, capable of probing the structure and dynamics of molecules (abstract), was previously available only at large, billion-dollar national facilities such as synchrotrons or free-electron lasers, where competition for use of the equipment is fierce. The new device, by husband-and-wife team Margaret Murnane and Henry Kapteyn based at JILA in Boulder, Colorado, might soon lie within the grasp of a university laboratory budget — perhaps allowing them to one day be as common in labs as electron microscopes are."
perhaps allowing them to one day be as common in labs as electron microscopes are.
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And back in my day, electron microscopes were big-ticket gear that only a few big labs could afford.
Now, get off of my lawn!
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Lacking <sarcasm> tags,
I imagine no worse than peeling a roll of sticky tape... will they ban these evil inventions as well?
Questions raise, answers kill. Raise questions to stay alive.
This is a very good experiment, but this is far from being competition for the large X-ray facilities. They are generating 10^5 photons in a 1% bandwidth at 1 KeV. The LCLS (X-ray Free Electron Laser at SLAC) generates about 10^13 photons in a ~0.3% bandwidth. (100 million times more) and operates at 6 X the repetition rate. The LCLS can also operate up to 10 KeV with the same pulse energy if needed. Near future facilities like the Euro XFEL will operate at 100X the average power of LCLS.
The very wide bandwidth of the harmonic generation described in the paper is very interesting because it can in principal support very short (few attosecond) bunches for future experiments, however at the moment they seem to be operating with 80 femtosecond bunches (or bunch trains), comparable to the FELs. (LCLS can run as short as a few femtoseconds with 10^12 photons). It is not clear how to compress their very broad band pulses to generate short pulses, though it is in principal possible. The minimum pulse length for FELs is likely to be around 100-200 attoseconds, so the harmonic generation scheme may eventually have a large advantage here.
It really is excellent work and a low power, ultra-short pulse tabletop X-ray source is a very valuable research tool, but I just want to point out that at the moment it is not a substitute for large X-ray facilities.
Josef Frisch
SLAC / LCLS