William & Mary

Society of Physics Students Tour of Jefferson Lab

 Photo credit: Joshua Hill, Phyiscs/Mathematics, William & Mary


After an introduction to the nuclear physics and materials science research programs of Jefferson Lab, the students had a unique opportunity to visit Jefferson Lab's Free Electron Laser (FEL).  With a power of 14 kW, Jefferson Lab's FEL is the highest-powered continuous infrared laser in the world.  In 2010, the FEL demonstrated lasing in the ultraviolet region as well.  William & Mary professors Michael Kelley and Gwyn Williams (photo) explained the operation of the FEL and of the experiments that can be performed with the intense beam of laser light.  Minutes after the tour left the facility, the vault was locked up again for another extended period of experiments.

 The second half of the tour was focused on the nuclear and particle physics experiments that make use of the energetic electron beam of the CEBAF accelerator.  Professors David Armstrong and Wouter Deconinck explained how spectrometers the size of a house are used to look deep inside the nucleus of atoms.  By striking the proton and neutrons in the nucleus with energetic electrons and detecting the scattered electrons in the spectrometers, physicists measure properties such as the charge distribution inside the neutron and search for signatures of undiscovered particles.