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Nave, C (Colin) wrote:
Inverse Compton or laser micro-undulator? Now we are getting fundamental!
I'm sure you're right Colin but for the non-physicist the good thing
about there being two equivalent ways to describe processes in quantum
mechanics is that often one is a lot easier to comprehend than the
other. The micro-undulator concept mirrors the properties of the
physical undulators that most of us are familiar with, that's why I
brought up the analogy (and truth be told, I didn't even recognize that
what you were saying was the same thing).
Bart
My understanding is that there are two ways of describing the process. They are
covered in pages 15-18 of the thesis at
http://www.slac.stanford.edu/cgi-wrap/getdoc/slac-r-632.pdf, the particle view
and the field view.
I believe either is equally valid. If you can understand how these two views
are related, you can also understand how photons can pass through two slits and
interfere. Also how x-rays are diffracted by a protein crystal and the
individual photons in the diffraction pattern counted on a photon counting
detector.
Perhaps there is additional insight (or even physics) in one of the
descriptions. However, I like the quote below
Colin
------------------------------------
'...Any other situation in quantum mechanics, it turns out, can always be
explained by saying, 'You remember the case of the experiment with the two
holes? It's the same thing.'
Richard P. Feynman
Lectures on Physics:
The Character of the Physical Law
-----Original Message-----
From: Bart Hazes [mailto:[EMAIL PROTECTED]
Sent: 10 July 2006 15:49
To: Nave, C (Colin)
Cc: Ranvir Singh; CCP4 Bulletin Board
Subject: Re: [ccp4bb]: Information on Comapct Light Source
My understanding is that this source uses the magnetic field of the
laser light as an undulator with about 10T field strength, virtually
perfect harmonic behaviour and a few thousand periods over the length of
the straight section because the period is only ~700nm long (or whatever
laser wavelength they end up using). Because of the high magnetic field
you can do with a much lower energy electron storage ring which allows
for the small size and "low" operating cost. You indeed change the
wavelength by changing the electron energy. Electron bunches are dumped
and a fresh one injected every few milliseconds so beam intensity
remains virtually constant.
My expectation is that this technology on paper has the qualitative
properties of an excellent undulator beamline but perhaps the brilliance
of a strong bending magnet beamline. I believe Donald Ruth is presenting
another seminar on his technology at the ACA later this month.
Ultimately we have to see a full system up and running to evaluate. The
last I heard, the first installation is planned for some time next year.
Bart
Nave, C (Colin) wrote:
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Ranvir
This question comes up occasionally (I was asked about this source last Friday).
As I understand it the source is based on a small low energy electron storage
ring and a high average power laser. The photons from the laser receive extra
energy by scattering from the electrons (the inverse Compton effect). The
energy of the electrons is chosen to give x-rays of our desired wavelength. The
set up is designed to give a high average photon flux/brightness. Other types
of inverse Compton facilities are based on linacs (for example) and short pulse
lasers to give a high peak flux of x-rays (short intense pulse) but with a
lower repetition rate.
I believe the aim of Compact Light Source is to get performance similar to a
bending magnet on a (second generation?) storage ring. This could sell provided
the cost is reasonable.
I presume they are building/testing their prototype and are not releasing too
much information at this stage. I have just looked at their web site and there
are some details there (http://www.lynceantech.com/sci_tech_cls.html).
Those thinking of upgrading their data collection facilities would clearly like
to know when the source would be available. I am afraid I can't help here.
Regards
Colin
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of
Ranvir Singh
Sent: 07 July 2006 11:31
To: CCP4 Bulletin Board
Subject: [ccp4bb]: Information on Comapct Light Source
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Dear members
I have been recently informed about 'mini synchrotron'
or Compact Light Source, being tested. Lyncean
Technologies claims to manufacture room size x- ray
source which can provide x-rays comparable in quality
and flux to those available at synchrotons. Yet their
website has little technical information.
I will highly appreciate if any one can provide me
with some insights about this new development
with best wishes
Ranvir
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Bart Hazes (Assistant Professor)
Dept. of Medical Microbiology & Immunology
University of Alberta
1-15 Medical Sciences Building
Edmonton, Alberta
Canada, T6G 2H7
phone: 1-780-492-0042
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