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Search Publications by: Wangchun Chen (Fed)

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Displaying 1 - 25 of 40

Beyond Single Tetrahedron Physics of the Breathing Pyrochlore Compound Ba 3 Yb 2 Zn 5 O 11

April 20, 2023
Author(s)
Rabindranath Bag, Sachith Dissanayake, Han Yan, Zhenzhong Shi, David Graf, Eun S. Choi, Casey Marjerrison, Franz Lang, Tom Lancaster, Yiming Qiu, Wangchun Chen, Stephen J. Blundell, Andriy H. Nevidomskyy, Sara Haravifard
Recently a new class of quantum magnets, the so-called breathing pyrochlore systems, have attracted much attention due to their potential to host exotic emergent phenomena. Here, we present magnetometry, thermal, muon-spin relaxation, and polarized

The Very Small-Angle Neutron Scattering Instrument at the National Institute of Standards and Technology

February 27, 2022
Author(s)
John Barker, James Moyer, Steven Kline, G. Jensen, Jeremy Cook, Cedric V. Gagnon, Elizabeth Kelley, Jean Philippe Chabot, Nicholas C. Maliszewskyj, Chirag B. Parikh, Wangchun Chen, C. Glinka
A description and the performance of the Very Small-Angle Neutron Scattering (VSANS) Diffractometer at the National Institute of Standards and Technology are presented. The measurement range of the instrument extends over three decades of momentum transfer

A Large Beam High Efficiency Radio Frequency Neutron Spin Flipper

June 21, 2021
Author(s)
Wangchun Chen, Ross W. Erwin, Peter Tsai, Md. T. Hassan, Nancy Hadad, Charles F. Majkrzak
A design for a radio-frequency (RF) neutron spin flipper obtained from magneto-static and neutron spin transport simulations is presented. The RF flipper constructed from this design provides a flipping probability of 0.999 or better for a beam size 6 cm

Demonstration of focusing Wolter mirrors for neutron phase and magnetic imaging

April 21, 2021
Author(s)
Daniel S. Hussey, Han Wen, Huarui Wu, Thomas R. Gentile, Wangchun Chen, David L. Jacobson, Jacob LaManna, B. Khaykovich
Image-forming focusing mirrors were employed to demonstrate two different modalities of neutron imaging, phase imaging with a far-field interferometer, and magnetic-field imaging through the manipulation of the neutron beam polarization. For the phase

Neutron Polarimetry Using a Polarized 3He Cell for the aCORN Experiment

November 16, 2020
Author(s)
Benjamin C. Schafer, W A. Byron, Wangchun Chen, B Collett, Maynard S. Dewey, Thomas R. Gentile, Md. T. Hassan, Gordon L. Jones, Alexander Komives, Fred E. Wietfeldt
The neutron polarization of the NG-C beamline at the NIST Center for Neutron Research was measured as part of the aCORN neutron beta decay experiment. Neutron transmission through a polarized 3He spin filter cell was recorded while adiabatic fast passage

Optimizing Magnetically Shielded Solenoids for Large Volume 3 He Neutron Spin Filters

October 2, 2020
Author(s)
Wangchun Chen, Md. Hassan, Ross Erwin, Shannon M. Watson, Thomas R. Gentile, G. L. Jones
An important consideration when designing a magnetostatic cavity for various applications is to maximize the ratio of the volume of field homogeneity to the overall size of the cavity. We report a design of a magnetically shielded solenoid that

Electric-field imaging using polarized neutrons

September 10, 2020
Author(s)
Y.- Y. Jau, Daniel S. Hussey, Thomas R. Gentile, Wangchun Chen
We experimentally demonstrate that electrically neutral particles, neutrons, can be used to directly visualize the electrostatic field inside a target volume that can be physically isolated or occupied. Electric field images are obtained using a spin

Antichiral Spin Order, its Soft Modes, and their Hybridization with Phonons in the Topological Semimetal Mn 3 Ge

August 3, 2020
Author(s)
Y. Chen, Jonathan Gaudet, S. Dasgupta, G. G. Marcus, J. Lin, T. Chen, T. Tomita, M. Ikhlas, Yang Zhao, Wangchun Chen, Matthew B. Stone, O. Tchernyshyov, S. Nakatsuji, Collin L. Broholm
Quantum materials with strong transport responses to disparate physical quantities are of great fundamental significance and may hold technological potentials. The interplay between interactions and topology drive such responses through the effects of

Sensitive neutron transverse polarization analysis using a 3He spin filter

July 7, 2020
Author(s)
Y.- Y. Jau, Wangchun Chen, Thomas R. Gentile, Daniel S. Hussey
We report an experimental implementation for neutron transverse polarization analysis that is able to detect a small angular change (10^-3 rad) of neutron spin orientation and works for both monochromatic and polychromatic neutron beams. Our approach

A Strategy for Handling Aberration in Spherical Neutron Polarimetry

December 11, 2019
Author(s)
Jacob Tosado, Wangchun Chen, Efrain E. Rodriguez
We present a strategy for identifying and correcting for aberration effects in Spherical Neutron Polarimetry. The transformation of the neutron beam polarization vector due to scattering from a material is determined with Spherical Neutron Polarimetry

Generation and Detection of Spin-Orbit Coupled Neutron Beams

October 8, 2019
Author(s)
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

Wide-Angle Polarization Analysis on the Multi-Axis Crystal Spectrometer for the Study of Collective and Single Particle Dynamics of Methanol at its Prepeak

July 1, 2019
Author(s)
Wangchun Chen, Shannon M. Watson, Yiming Qiu, Jose Rodriguez Rivera, Antonio Faraone
Neutron polarization analysis capability with a large scattering angle and momentum transfer coverage has not been widely implemented for the separation of coherent and incoherent quasi-elastic neutron scattering (QENS) spectra. A feasibility test for soft

Spin Stripe Order in a Square Planar Trilayer Nickelate

June 18, 2019
Author(s)
Junjie Zhang, D. M. Pajerowski, A. S. Botana, Hong Zheng, Leland Harriger, Jose Rodriguez Rivera, J. Ruff, N. J. Schreiber, B. Wang, Yu-Sheng Chen, Wangchun Chen, M. R. Norman, S. Rosenkranz, J. F. Mitchell, D. Phelan
Trilayer nickelates, which exhibit a high degree of orbital polarization combined with an electron (d 8.67 ) corresponding to overdoped cuprates, have been recognized as promising candidates for achieving high-T c superconductivity. One such material, La 4

Quantum Critical Behavior in Ce(Fe 0.76 Ru 0.24 ) 2 Ge 2

May 7, 2019
Author(s)
Wouter Montfrooij, Tom Heitmann, Yiming Qiu, Shannon M. Watson, Ross Erwin, Wangchun Chen, Yang Zhao, Meigan Aronson, Yingkai Huang, Anne de Visser
Systems with embedded magnetic ions that exhibit a competition between magnetic order and disorder down to absolute zero can display unusual low temperature behaviors of the resistivity, hyperscaling behavior in which the relaxation back to equilibrium

aCORN: an experiment to measure the electron-antineutrino correlation coefficient in free neutron decay

August 1, 2017
Author(s)
Maynard S. Dewey, Fred B. Bateman, Wangchun Chen, Thomas R. Gentile, Md. T. Hassan, Michael P. Mendenhall, Jeffrey S. Nico, Brian Collett, Jim Byrne, William Byron, Guillaume Darius, Christina DeAngelis, Gordon L. Jones, Alexander Komives, Alexander Laptev, George Noid, Hyeonseo Park, Ed Stephenson, I Stern, K Stockton, Bob Trull, Fred Wietfeldt, B G. Yerozolimsky
We describe an apparatus used to measure the electron-neutrino angular correlation coefficient, a, in free neutron decay. The apparatus employs a novel measurement technique in which the angular correlation is converted into a proton time-of-flight

Higgs Amplitude Mode in a Two-Dimensional Quantum Antiferromagnet near the Quantum Critical Point0

July 4, 2017
Author(s)
Tao Hong, Masashige Matsumoto, Yiming Qiu, Wangchun Chen, Thomas R. Gentile, Shannon M. Watson, Firas F. Awwadi, Mark M. Turnbull, Sachith E. Dissanayake, Harish Agrawal, Rasmus Toft-Petersen, Bastian Klemke, Kris Coester, Kai P. Schmidt, David A Tennant
Spontaneous symmetry-breaking quantum phase transitions play an essential role in current condensed matter physics 1-3 . The collective excitations in the broken-symmetry phase near the quantum critical point can be characterized by fluctuations of phase

Spin-Analyzed SANS for Soft Matter Applications

June 20, 2017
Author(s)
WangChun Chen, John Barker, Ronald L. Jones, Kathryn Krycka, Shannon Watson, Cedric Victor Lucien Gagnon, T. Perevozchivoka, Paul Butler, Thomas R. Gentile
The small angle neutron scattering (SANS) of nearly Q-independent nuclear spin-incoherent scattering from hydrogen present in most soft matter and biology samples may raise an issue in structure determination in certain soft matter applications. This is

Identification of the Low-Energy Excitations in a Quantum Critical System

December 20, 2016
Author(s)
Tom Heitmann, Jagat Lamsal, Shannon M. Watson, Ross Erwin, Wangchun Chen, Yang Zhao, Wouter Montfrooij
We have identified low-energy magnetic excitations in a doped quantum critical system by means of polarized neutron scattering experiments. The presence of these excitations could explain why Cd(Fe 0.76 Ru 0.24 ) 2 Ge 2 displays dynamical scaling in the

Recent Advancements of Wide-Angle Polarization Analysis with 3 He neutron Spin Filters

October 10, 2016
Author(s)
WangChun Chen, Thomas R. Gentile, Qiang NMN Ye, A. Kirchhoff, Shannon Watson, Jose A. Rodriguez, Yiming Qiu, Collin L. Broholm
Wide-angle polarization analysis with polarized 3 He based neutron spin filters (NSFs) has recently been employed on the Multi-Axis Crystal Spectrometer (MACS) at the National Institute of Standards and Technology Center for Neutron Research (NCNR). Over

A 3He beam stop for minimizing gamma-ray and fast-neutron background

August 6, 2016
Author(s)
Danyal J. Turkoglu, Robert G. Downing, Wangchun Chen, Dagistan Sahin, Jeremy C. Cook
Prompt gamma-ray activation analysis facilities with high neutron currents (≥109 s-1) generate triton-induced fast neutrons from 6Li-loaded collimators and beam stops at rates that soon damage gamma-ray detectors. We develop an alternative beam stop design

A New Cold Neutron Imaging Instrument at NIST

July 6, 2015
Author(s)
Daniel S. Hussey, Christoph W. Brocker, David L. Jacobson, Thomas R. Gentile, Wangchun Chen, Elias M. Baltic, DV Baxter, J. Doskow, Muhammad D. Arif
The NIST neutron imaging program will build a new imaging instrument in the NCNR guide hall at the end of the neutron guide NG-6, beginning operation in summer of 2014. The NG-6 guide has a spectrum that is strongly peaked at a neutron wavelength of 5 Å