Light Sources—New Sources of Light to Illuminate Sub-Atomic Particles

Light sources are extremely concentrated x-rays and ultraviolet radiation typically generated by a synchrotron in order to illuminate subatomic particles. There are almost seventy sites working on lightsource applications around the world. Synchrotrons are used to generate these specific wavelengths of light.

According to Scott Hannahs of the National High Magnetic Field Lab, a pulse of charged "particles" usually electrons are generated and bent by magnets. Magnets bend electric current which is flowing electric charges. The electrons (usually, but can be other charged particles) are acellerated with electric fields and the beam is bent by magnets. The bending of the beam causes the emission of light.

A Synchrotron uses an arc engine to generate a pulse of light that is accelerated to 99% the speed of light. The pulse creates x-rays which shoot through a sample creating scattering which forms an image of the atomic structure of the sample. If you want to hear a nine year old explain how a synchrotron works then check out this video.

A typical experiment consists of spectroscopy, scattering, and imaging. Spectroscopy studies the energies of the particles emitted by samples that are exposed to the light-source beam. Scattering (diffraction technique) looks at the patterns of light produced when the x-rays deflect off the atomic structures of the sample. Imaging techniques use the light-source beam to capture pictures of the samples.

To learn more about the instrumentation used in Synchrotrons I turned to Wikipedia which broke the instrumentation into the following categories:

Beamline - line in linear accelerator along which a beam of particles travel.

Collimator - a device that filters a stream of rays so that only those traveling parallel to a specified direction are allowed through.

Crystal monochromator - select a defined wavelength of the radiation.

Insertion device -- produces highly-brilliant, forward-directed and quasi-monochromatic synchrotron radiation.

Undulator -- an insertion device from high-energy physics and usually part of a larger installation, a synchrotron storage ring. It consists of a periodic structure of dipole magnets alternating the wavelength.

Wiggler -- a series of magnets designed to deflect ('wiggle') a beam of charged particles (invariably electrons or positrons) inside a storage ring of a synchrotron.

Best regards,
Hall T.