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Bart I (also a non physicist) agree that having two complementary (Bohr's term) descriptions is useful as it gives us a fighting chance of understanding at least one of them (and thus perhaps posing as physicists). Yes, the undulator based description is illuminating and you were right to illuminate. What I usually do in these circumstances is mix the two approaches at the same time. However (from Wikipedia" "can either behave as a particle or as wave, but never simultaneously as both" "a stronger manifestation of the particle nature leads to a weaker manifestation of the wave nature and vice versa." So pay your money and take your choice. I guess this also applies to buying one of the devices! Cheers Colin -----Original Message----- From: Bart Hazes [mailto:[EMAIL PROTECTED] Sent: 10 July 2006 18:54 To: Nave, C (Colin) Cc: Ranvir Singh; CCP4 Bulletin Board Subject: Re: [ccp4bb]: Information on Comapct Light Source 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: > >>*** 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 ==============================================================================
