Reply To: Okay, Let's Stop The BAKE SALE mentality and get SERIOUS

[jamesr]

Yes I do has access via my institution.

This has nothing to do with cavitation, acoustic, shocks etc. pressure & temperature are meaningless on this energy/time-scale.
The plasma ‘wake’ is the interaction with the huge EM fields of the laser pulse – not a fluid-like response, you have to think in terms of kinetics of individual ions/electrons.

Laser wakefield acceleration is nothing new, see: http://en.wikipedia.org/wiki/Plasma_acceleration
Similarly there have been improvements in Free Electron Lasers in the last 10 years or so.

This experiment was not about the energy of the accelerated electrons, 700MeV in this case, compared to >1GeV in others. Or the intensity (number of photons) of the resulting X-ray beam.
It was that the spectrum of the betatron excited beam of high energy photons peaked around 150keV rather than the ~10keV typical of previous experiments. Thus the X-rays are now in the ‘gamma-ray’ portion of the EM-spectrum rather than the relatively soft X-rays. (NB. traditionally the gamma terminology is reserved for photons emitted by nuclei rather than electrons)

Although it talked about gamma rays the Science Daily write-up failed to mention the key figure of 150keV, and instead went on about the intensity – which it then quoted incorrectly.

High intensity is needed, but it is the combination of high photon energy, and short pulse duration is key for imaging proteins etc. and make this potentially a big step forward in having a lab sized machine rather than the huge synchrotron accelerators.