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Search Publications by: Charles W Clark (Assoc)

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Displaying 1 - 25 of 225

Experimental Realization of Neutron Helical Waves

May 11, 2022
Michael G. Huber, Charles W. Clark, Dmitry Pushin, Connor Kapahi, Lisa DeBeer-Schmitt, David Cory, Huseyin Ekinci, Melissa Henderson, Dusan Sarenac
Methods of preparation and analysis of structured waves of light, electrons, and atoms have been advancing rapidly. Despite the proven power of neutrons for material characterization and studies of fundamental physics, neutron science has not been able to

Blackbody Radiation Shift in a 43 Ca + Ion Optical Frequency Standard

October 12, 2021
B Arora, M S. Safronova, Charles W. Clark
Motivated by the prospect of an optical frequency standard based on 43Ca+, we calculate the blackbody radiation (BBR) shift of the 4s1/2 - 3d5/2 clock transition, which is a major component of the uncertainty budget. The calculations are based on the

Generation and Detection of Spin-Orbit Coupled Neutron Beams

October 8, 2019
Dusan Sarenac, Connor Kapahi, Wangchun Chen, Charles W. Clark, David G. Cory, Michael G. Huber, Ivar Taminiau, Kirill Zhernenkov, Dmitry A. Pushin
Spin-orbit coupling of light has come to the fore in nano-optics and plasmonics, and is a key ingredient of topological photonics and chiral quantum optics. We demonstrate a basic tool for incorporating analogous effects into neutron optics: the generation

Methods for preparation and detection of neutron spin-orbit states

October 10, 2018
Michael G. Huber, D. Sarenac, J. Nsofini, I. Hincks, David Cory, Muhammad D. Arif, Charles W. Clark, D. A. Pushin
The generation and control of neutron orbital angular momentum (OAM) states and spin correlated OAM (spin-orbit) states provides a powerful probe of materials with unique penetrating abilities and magnetic sensitivity. We describe techniques to prepare and

Nearly-linear light cones in long-range interacting quantum systems

April 13, 2015
Michael S. Foss-Feig, Zhexuan Gong, Charles W. Clark, Alexey V. Gorshkov
In non-relativistic quantum theories with short-range Hamiltonians, a velocity $v$ can be chosen such that the influence of any local perturbation is approximately confined to within a distance $r$ until a time $t \sim r/v$, thereby defining a linear light

Noble Gas Excimer Scintillation Following Neutron Capture in Boron Thin Films

April 11, 2014
Alan K. Thompson, Jacob McComb, Charles W. Clark, Michael A. Coplan, Mohamad Al-Sheikhly, Robert E. Vest
Far-ultraviolet (FUV) scintillation signals have been measured in heavy noble gases (argon, krypton, xenon) following boron-neutron capture (10B(n,α)7Li) in 10B thin films. The observed scintillation yields are comparable to the yields from some liquid and

Hysteresis in Quantized Superfluid Atomtronic Circuit

February 14, 2014
Stephen P. Eckel, Jeffrey Lee, Fred Jendrzejewski, Noel Murray, Charles W. Clark, Christopher J. Lobb, William D. Phillips, Edwards Mark, Gretchen K. Campbell
Atomtronics is an emerging interdisciplinary field that seeks new functionality by creating devices and circuits where ultra-cold atoms play a role analogous to the electrons in electronics. Hysteresis in atomtronic circuits may prove to be a crucial

Light-Wave Mixing with Quantum Gases

May 1, 2013
Lu Deng, Edward W. Hagley, R Q. Wang, Charles W. Clark
Nonlinear optics has come a long way since the laser. This article reviews recent progress in coherent light-matter wave mixing and introduces some new concepts that will reframe future research directions.

1932 A watershed year in nuclear physics

March 4, 2013
Joseph Reader, Charles W. Clark
1932 was the year for an amazing series of discoveries in physics. This started with the announcement of the discovery of deuterium, followed by the discoveries of the neutron and the positron, as well as artificial disintegration of nuclei by accelerators

Light, atoms and nuclei: the optical discovery of deuterium

May 1, 2012
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
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
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
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
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
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
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
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
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
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
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
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
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

Quantum Key Distribution System Operating at Sifted-Key Rate Over 4 Mbit/s 1

June 1, 2009
Xiao Tang, Lijun Ma, Alan Mink, Anastase Nakassis, Hai Xu, Barry J. Hershman, Joshua C. Bienfang, David H. Su, Ronald F. Boisvert, Charles W. Clark, Carl J. Williams
A complete fiber-based polarization encoding quantum key distribution (QKD) system based on the BB84 protocol has been developed at National Institute of Standard and Technology (NIST). The system can be operated at a sifted key rate of more than 4 Mbit/s