Synchrotrons light
Synchrotron light is unique in its intensity and
brilliance and it can be generated across the range of the
electromagnetic spectrum: from infrared to x-rays.
• a magnetic field forces a flying electron into a circular orbit.
• the elecron reacts to this force with the emission of electromagnetic
radiation (=synchrotron light).
• the spectrum of this synchrotron light is shifted towards short
wavelengths due to the Doppler effect of a moving light source.
• in the case of SLS the spectrum ranges from infrared light to soft and
hard X-rays.
• to make an efficient synchrotron light source one arranges many
magnets into a storage ring, where the high energy electrons can
circulate for hours.
• In a socalled undulator one has a periodic array of magnets with
alternating polarity of the magnetic field. This forces the electrons
into a slalom course. This in turn concentrates the synchrotron light
into discrete wavelenghts.
• the synchrotron light is guided tangentially away from the storage
ring through beamlines to different experimental hutches. Each
experimental group has control over its own undulator and can select
thus its own wavelength.
• contrary to X-rays, produced in a conventional X-ray tube, the intense
synchrotron light beams are sharply focused like a laser beam.
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