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Inverse Compton or laser micro-undulator? Now we are getting fundamental! 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: > *** For details on how to be removed from this list visit the *** > *** CCP4 home page http://www.ccp4.ac.uk *** > > > 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 > > > *** For details on how to be removed from this list visit the *** > *** CCP4 home page http://www.ccp4.ac.uk *** > > > 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 > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > > -- ============================================================================== 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 fax: 1-780-492-7521 ==============================================================================
