Gwyn P. Williams
Photo taken October 2012
12000 Jefferson Avenue - Suite 21
Newport News, VA 23606
gwyn at jlab.org
My science is based at Jefferson Lab
in Newport News, Virginia. I am also an
adjunct faculty member at Hampton University and the College of
William and Mary. Since obtaining
my PhD from Sheffield University in the UK in 1971, I have
co-authored over 260 research publications, and also written
several book chapters. I was the 1990 co-recipient of
an R&D 100 award for developing a wavefront dividing
interferometer for use with ultrabright sources. I am a Fellow of the
American Physical Society.
My research has involved understanding the fundamental physical
behavior of materials as determined by photoemission studies of
the electronic structure, and infrared studies of the
vibrational dynamics of adsorbates. This
research has motivated a lifelong parallel development of
ultra-bright light sources as probes, a path that took me to the
Daresbury synchrotron (NINA), Tantalus, NSLS and to JLab's FEL.
I built vuv/soft x-ray facilities at the NSLS and initiated
infrared synchrotron radiation activities there. At
Jefferson Lab I helped develop the THz regime using the
ultrafast facilities that are part of the FEL facility. Current
research programs involve ultrafast pump-probe dynamics of novel
materials and of bonding vibrational modes in both time and
frequency domains. 4th generation light
sources are a key tool for such studies, and I have been
involved with a team that has proposed an extension of the
JLab FEL into the electronic excitation region, 10 - 100 eV in
the fundamental, with useful harmonics up to 500 eV.
The bulk of my
career has been at the national labs, 5 as a user at Daresbury
Lab, 21 years on the staff of Brookhaven National
Laboratory in New York, and 14 at Jefferson Lab in Virginia.
Jefferson Laboratory is
in Newport News, Virginia and operates a Free Electron Laser which
is among the first of the 4th generation light sources to be
operating in the USA, another being the LCLS at SLAC. The
JLab FEL runs at a very high repetition rate and is capable of
high average as well as peak power because it uses
superconducting radio-frequency cavities and re-circulates the
electron beam with energy recovery. The FEL initially ran
in the infrared, but recently we have been driving to higher
photon energies, and with harmonics are now the brightest source
in the vacuum ultraviolet region where there are no table-top
lasers at all.
Specifically the Jefferson Lab FEL is a sub-picosecond, tunable
light source covering the range down to 124 nm in the vacuum
ultraviolet using harmonics, and running from 350
nanometers in the fundamental to 14 microns in the
mid-infrared. Pulse energies are up to 300 microJoules,
and repetition rates can go up to 75 MHz. Not all parameters can
be satisfied simultaneously but average powers in excess of 10
kW have been demonstrated in the infrared. We also have a
high power broadband THz laboratory whose source is the electron
beam in the FEL. This is a broadband source covering the
range 0.1 - 5 THz and with an average power of 100 watts.
is my google_scholar profile.
Here's a list of my publications.
Brookhaven National Laboratory
Montana State University
Leicester University (UK)
Sheffield University (UK)
Hull University (UK)
Lots of people ask me about the Binding
Energies of the Elements
, for which I welcome any updates by
e-mail, see address above. I put the data into a periodic
table based on an idea of Cliff Olson, which is available as a 24"x36"
When I am not doing physics I am often calling
contradances), or even dancing.
October 4, 2013