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Search Publications by: Charles W Clark (Assoc)

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Displaying 26 - 50 of 447

Light, atoms and nuclei: the optical discovery of deuterium

May 1, 2012
Author(s)
Charles W. Clark, Joseph Reader
Deuterium was discovered by atomic spectroscopy 80 years ago, and led to the rapid development of nuclear energy and isotope chemistry. Atomic spectroscopy of deuterium remains vibrant, with a recent application to understanding the early universe.

Detecting Paired and Counterflow superfluidity via dipole oscillations

October 27, 2011
Author(s)
Anzi A. Hu, Ludwig G. Mathey, Eite Tiesinga, Ippei Danshita, Carl J. Williams, Charles W. Clark
We suggest an experimentally feasible procedure to observe paired and counterflow superfluidity in ultra-cold atom systems. We study the time evolution of one-dimensional mixtures of bosonic atoms in an optical lattice following an abrupt displacement of

SURF III: A flexible Synchrotron Radiation Source for Radiometry and Research

September 1, 2011
Author(s)
Uwe Arp, Charles W. Clark, Lu Deng, Nadir S. Faradzhev, Alex P. Farrell, Mitchell L. Furst, Steven E. Grantham, Edward W. Hagley, Shannon B. Hill, Thomas B. Lucatorto, Ping-Shine Shaw, Charles S. Tarrio, Robert E. Vest
The calculability of synchrotron radiation (SR) makes electron storage rings wonderful light sources for radiometry. The broadband nature of SR allows coverage of the whole spectral region from the x-ray to the far-infrared. Compact low-energy storage

A Special Functions Handbook for the Digital Age

August 1, 2011
Author(s)
Ronald F. Boisvert, Charles W. Clark, Daniel W. Lozier, Frank W. Olver
The NIST Digital Library of Mathematical Functions (DLMF) is a reference work providing information on the properties of the special functions of applied mathematics. It is a successor to the highly successful NBS Handbook of Mathematical Functions

Far-ultraviolet signatures of the 3He(n,tp) reaction in noble gas mixtures

December 8, 2010
Author(s)
Patrick Hughes, Alan K. Thompson, Michael Coplan, Robert E. Vest, Charles W. Clark
Previous work showed that the 3He(n,tp) reaction in a cell of 3He at atmospheric pressure generated tens of far-ultraviolet photons per reacted neutron. Here we report amplification of that signal by factors of 1000 and more when noble gases are added to

A Green Laser Pointer Hazard

August 2, 2010
Author(s)
Jemellie Galang, Alessandro Restelli, Edward W. Hagley, Charles W. Clark
An inexpensive green laser pointer was found to emit 20 mW of infrared radiation during normal use. This is potentially a serious hazard that would not be noticed by most users of such pointers. We find that the problem derives from an unsafe design, and

Ettore Majorana and the birth of autoionization

July 2, 2010
Author(s)
Charles W. Clark, Ennio Arimondo, William C. Martin
In the early days of theoretical atomic spectroscopy, Ettore Majorana (1906-1938?) solved several outstanding problems by developing the theory of autoionization. Later literature makes only sporadic references to this accomplishment. Reviewing his work in

The NIST Handbook of Mathematical Functions

May 12, 2010
Author(s)
Frank W. Olver, Daniel W. Lozier, Ronald Boisvert, Charles W. Clark
The NIST Handbook of Mathematical Functions supplies validated reference information in 36 chapters on a wide selection of important mathematical functions, covering the properties necessary for their use in scientific applications, together with general

RECIST vs. Volume Measurement in Medical CT Using Ellipsoids of Known Size

April 12, 2010
Author(s)
Zachary H. Levine, Bruce R. Borchardt, Nolan J. Brandenburg, Charles W. Clark, Balasubramanian Muralikrishnan, Craig M. Shakarji, Joseph J. Chen, Eliot L. Siegel
(a) Purpose: We wanted to test the extent to which two common methods of determining the sizes of tumors would perform when compared to a statistically significant number of well-characterized reference objects. The size of the objects was chosen to

Ultracold Atom Spin Field Effect Transistor

September 14, 2009
Author(s)
Jay Vaishnav, Julius Ruseckas, Charles W. Clark, Gediminas Juzelunas
We propose a method of constructing cold atom analogs of the spintronic device known as the Datta-Das transistor (DDT), which despite its seminal conceptual role in spintronics, has never been successfully realized with electrons. We propose two

Collisional cooling of ultra-cold atom ensembles using Feshbach resonances

September 8, 2009
Author(s)
Ludwig G. Mathey, Eite Tiesinga, Paul S. Julienne, Charles W. Clark
We propose a new type of cooling mechanism for ultra-cold fermionic atom ensembles, which capitalizes on the energy dependence of inelastic collisions in the presence of a Feshbach resonance. We first discuss the case of a single magnetic resonance, and

Counterflow and paired superfluidity in one-dimensional Bose mixtures in optical lattices

August 24, 2009
Author(s)
Anzi A. Hu, Ludwig G. Mathey, Ippei Danshita, Eite Tiesinga, Carl J. Williams, Charles W. Clark
We study the quantum phases of mixtures of ultra-cold bosonic atoms held in an optical lattice that confines motion or hopping to one spatial dimension. The phases are found by using Tomonaga-Luttinger liquid theory as well as the numerical method of time

Experimental Study of High Speed Polarization -Coding Quantum Key Distribution with Sifted -Key Rates Over Mbit/s

June 1, 2009
Author(s)
Xiao Tang, Lijun Ma, Alan Mink, Anastase Nakassis, Barry J. Hershman, Joshua C. Bienfang, David H. Su, Ronald F. Boisvert, Charles W. Clark, Carl J. Williams
We have demonstrated a polarization encoded, fiber-based quantum key distribution system operating at 850 nm in the B92 protocol. With a quantum bit transmission rate i.e. optical pulse driving frequency of 625 MHz and a mean photon number of 0.1, we