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  1. Miles Hall

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Miles Hall - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced Nuclear Energy

  2. Fermilab Wilson Hall and Vicinity

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Wilson Hall and Vicinity Wilson Hall Ramsey Auditorium Booster Linac Antiproton Source Leon M. Lederman Science Education Center...

  3. Jefferson Lab Experimental Hall D

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    D Privacy and Security Notice Skip over navigation search Group This site's design is only visible in a graphical browser that supports web standards, but its content is accessible to any browser. Concerns? Hall D Navigation Hall D Main Hall D Engineering Hall D Staff Hall D Safety print version Hall D in October 2014 Related Links CEBAF at 12 GEV JLab Visitor's Center JLab Virtual Tour JLab page for scientists Experimental Hall A Experimental Hall B Experimental Hall C Hall D Task List - HDList

  4. Mary Hall Salishan

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    From Hall et al, "Maximizing Multiprocessor Performance with the SUIF Compiler", IEEE Computer, Dec. 1996. 50% higher Specfp95 ratio than previously reported 3 1990s View *...

  5. WORKFORCE DIVERSITY TOWN HALL

    Energy Savers [EERE]

    ... fracturing our communities." Secretary Hillary Rodham Clinton WORKFORCE DIVERSITY TOWN HALL Agenda I. Welcome Mel Williams, Jr., Associate Deputy Secretary II. Opening Remarks Dr. ...

  6. Hall A Annual Report 2013

    SciTech Connect (OSTI)

    Dalton, Mark M.

    2014-02-01

    Report over the experimental activities in Hall A at Thomas Jefferson National Accelerator Facility during 2013.

  7. Hall Ammendment Policy

    Broader source: Energy.gov [DOE]

    Joint statement providing interim policy on processing proposals for leasing DOE real property using the authority in 42 U.S.C. 7256, commonly referred to as the "Hall Amendment."

  8. Jefferson Lab Experimental Hall B

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hall B Privacy and Security Notice Skip over navigation search Group Please upgrade your browser. This site's design is only visible in a graphical browser that supports web standards, but its content is accessible to any browser. Concerns? Hall B Navigation Hall B Main CLAS CLAS12 Other Expts Run Info Publications Public Interest print version Hall B Main CLAS Collaboration and Hall B CLAS Collaboration Information Phonebook, Opt-in, and Database Reviews and Service Work Login Working Groups

  9. Unconventional Quantum Hall Effect and Tunable Spin Hall Effect...

    Office of Scientific and Technical Information (OSTI)

    to an Isolated MoS2 Trilayer Title: Unconventional Quantum Hall Effect and Tunable Spin Hall Effect in Dirac Materials: Application to an Isolated MoS2 Trilayer Authors: Li, ...

  10. Experimental Hall C | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    C Jefferson Lab has four experimental halls. Hall C is 150 feet in diameter and 60 feet tall. Hall C houses a High Momentum Spectrometer and provides space for large-installation experiments. These are stand-alone experiments requiring unique or highly specialized detectors, magnets and targeting systems. The research equipment in Hall C is used to study the weak charge of the proton, form factors of simple quark systems, the transition from hadrons to quarks and nuclei with a strange quark

  11. Modeling the Hall Thruster

    SciTech Connect (OSTI)

    Fisch, N.J.; Fruchtman, A.

    1998-08-01

    The acceleration of the plasma in the Hall thruster to supersonic velocities is examined by the use of a steady state model. Flows that are smooth across the sonic transition plane are found. The possibility of generating flows in which the acceleration across the sonic plane is abrupt, is also studied.

  12. Experimental Hall A | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A Jefferson Lab has four experimental halls. Hall A is the largest of these four experimental staging areas. It is 174 feet across and 80 feet tall from the floor to the highest spot on its domed ceiling. The foundation for the hall is 35 feet below ground. Hall A is outfitted with two primary detector systems - both high-resolution spectrometers, each weighing about 3 million pounds or 1,500 short tons. The hall is used primarily for experiments that study the structure of the nucleus and the

  13. Cylindrical geometry hall thruster

    DOE Patents [OSTI]

    Raitses, Yevgeny; Fisch, Nathaniel J.

    2002-01-01

    An apparatus and method for thrusting plasma, utilizing a Hall thruster with a cylindrical geometry, wherein ions are accelerated in substantially the axial direction. The apparatus is suitable for operation at low power. It employs small size thruster components, including a ceramic channel, with the center pole piece of the conventional annular design thruster eliminated or greatly reduced. Efficient operation is accomplished through magnetic fields with a substantial radial component. The propellant gas is ionized at an optimal location in the thruster. A further improvement is accomplished by segmented electrodes, which produce localized voltage drops within the thruster at optimally prescribed locations. The apparatus differs from a conventional Hall thruster, which has an annular geometry, not well suited to scaling to small size, because the small size for an annular design has a great deal of surface area relative to the volume.

  14. Experimental Hall B | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and electromagnetic calorimeters for electron and neutral particle identification. Major research programs in Hall B include experiments to measure the spectrum of excited ...

  15. Experimental Hall B | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    B Jefferson Lab has four experimental halls. Hall B is the smallest of the experimental staging areas. It is 98 feet in diameter and 65 feet from floor to ceiling. Experiments that take data in Hall B employ beams of either electrons or photons. From 1995 to 2012, the heart of the Hall B physics program involved the use of the CEBAF Large Acceptance Spectrometer, or CLAS. This detector system spanned nearly the full angular range about the target and was specifically developed for the study of

  16. Experimental Hall D | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    D A fourth experimental hall, known as Hall D, is currently under construction and is scheduled to begin experiments in 2015. The Hall D project consists of an extension to the accelerator tunnel to house a new beam transport line, a dedicated magnet to tag photons created in beam-target interactions, a counting house, cryogenics plant and service buildings. When it is completed, Hall D will make it possible for scientists to study what are known as exotic mesons or hybrids. You can learn more

  17. ARM - Welcome to Study Hall

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox ...

  18. Directions to Wilson Hall, Fermilab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Wilson Hall, the central laboratory building of Fermi National Accelerator Laboratory, as shown on the map below. Ramsey Auditorium is located at the south end of Wilson ...

  19. Town Hall Questions Answered

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8, 2014 CBFO Manager's weekly update to local residents Read Carlsbad Field Office Manager Joe Franco's letter to Eddy and Lea County residents for the week of April 14: at http://1.usa.gov/1mkxm7b Town Hall Questions Answered Q. What is the condition of Panel 7 right now? A. Work teams entering the underground facility as part of ongoing Phase 3 activities are still working to determine the full condition of Panel 7. Initial entries indicate good roof conditions. Q. What's the presumed reason

  20. Forest County Potawatomi Community Wundar Hall Project

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Wundar Hall Project Wundar Hall is a 34,000 sq ft building located on the former ... by the Tribe and taken into Trust in 1990. Wundar Hall is currently not in use. ...

  1. QER- Comment of Addison Hall

    Broader source: Energy.gov [DOE]

    I and my family own land in Ashfield next to the proposed Kinder Morgan/Tennessee Pipeline route. We are opposed to the pipeline for a variety of reasons, including the highly questionable need for the proposed commodity increase and the inevitable damage to the environment and communities along the proposed route. Addison Hall for the Hall Family Trust.

  2. Anthony Kathryn Hall | Open Energy Information

    Open Energy Info (EERE)

    Anthony Kathryn Hall Jump to: navigation, search Name: Anthony & Kathryn Hall Place: United Kingdom Sector: Wind energy Product: UK-based private wind farm in Highland. References:...

  3. Second Generation Fractional Quantum Hall Effect

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Generation Fractional Quantum Hall Effect - Sandia Energy Energy Search Icon Sandia Home ... Second Generation Fractional Quantum Hall Effect HomeHighlights - Energy Research...

  4. Tuning giant anomalous Hall resistance ratio in perpendicular Hall balance

    SciTech Connect (OSTI)

    Zhang, J. Y.; Yang, G.; Wang, S. G. E-mail: ghyu@mater.ustb.edu.cn; Liu, J. L.; Wang, R. M.; Amsellem, E.; Kohn, A.; Yu, G. H. E-mail: ghyu@mater.ustb.edu.cn

    2015-04-13

    Anomalous Hall effect at room temperature in perpendicular Hall balance with a core structure of [Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4} has been tuned by functional CoO layers, where [Pt/Co]{sub 4} multilayers exhibit perpendicular magnetic anisotropy. A giant Hall resistance ratio up to 69 900% and saturation Hall resistance (R{sub S}{sup P}) up to 2590 mΩ were obtained in CoO/[Pt/Co]{sub 4}/NiO/[Co/Pt]{sub 4}/CoO system, which is 302% and 146% larger than that in the structure without CoO layers, respectively. Transmission electron microscopy shows highly textured [Co/Pt]{sub 4} multilayers and oxide layers with local epitaxial relations, indicating that the crystallographic structure has significant influence on spin dependent transport properties.

  5. Sec. Chu Online Town Hall

    Office of Energy Efficiency and Renewable Energy (EERE)

    Secretary Steven Chu hosted an online town hall to discuss the clean energy and innovation agenda President Obama laid out in his 2011 State of the Union address. (January 26, 2011)

  6. Science and Energy Town Hall

    Broader source: Energy.gov [DOE]

    Watch a live broadcast of the Science & Energy Town Hall on Wednesday, January 20, 2016 from 2:30 p.m. to 3:30 p.m. EST.

  7. Experimental Hall C | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Hall C is used to study the weak charge of the proton, form factors of simple quark systems, the transition from hadrons to quarks and nuclei with a strange quark embedded....

  8. Optimization of Cylindrical Hall Thrusters

    SciTech Connect (OSTI)

    Yevgeny Raitses, Artem Smirnov, Erik Granstedt, and Nathaniel J. Fi

    2007-07-24

    The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation. __________________________________________________

  9. Optimization of Cylindrical Hall Thrusters

    SciTech Connect (OSTI)

    Yevgeny Raitses, Artem Smirnov, Erik Granstedt, and Nathaniel J. Fisch

    2007-11-27

    The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation.

  10. Jefferson Lab Experimental Hall C

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    C Privacy and Security Notice Skip over navigation search Group This site's design is only visible in a graphical browser that supports web standards, but its content is accessible to any browser. Concerns? Hall C Navigation Users Public Interest print version HES, HKS and Splitter Qweak spectrometer used to measure proton weak charge 12 GeV Upgrade Upgrade information 12 GeV Experiments SHMS-HMS User's Group User's Group mailing list Newsletter 12 GeV wiki Hall C Collaboration Information

  11. Spin Hall controlled magnonic microwaveguides

    SciTech Connect (OSTI)

    Demidov, V. E.; Urazhdin, S.; Rinkevich, A. B.; Reiss, G.; Demokritov, S. O.

    2014-04-14

    We use space-resolved magneto-optical spectroscopy to study the influence of spin Hall effect on the excitation and propagation of spin waves in microscopic magnonic waveguides. We find that the spin Hall effect not only increases the spin-wave propagation length, but also results in an increased excitation efficiency due to the increase of the dynamic susceptibility in the vicinity of the inductive antenna. We show that the efficiency of the propagation length enhancement is strongly dependant on the type of the excited spin-wave mode and its wavelength.

  12. Town Hall meeting | OpenEI Community

    Open Energy Info (EERE)

    picture Submitted by Graham7781(2017) Super contributor 16 November, 2012 - 11:23 LEDS the focus of Monday's 10 a.m. Town Hall Meeting LEDS Town Hall meeting What: OpenEI's...

  13. The fluctuation induced Hall effect

    SciTech Connect (OSTI)

    Shen, W.; Prager, S.C.

    1993-02-01

    The fluctuation induced Hall term, [le][approximately][ovr J] [times] [approximately][ovr B][ge], has been measured in the MST reversed field pinch. The term is of interest as a possible source of current self-generation (dynamo). It is found to be non-negligible, but small in that it can account for less than 25% of the dynamo driven current.

  14. The fluctuation induced Hall effect

    SciTech Connect (OSTI)

    Shen, W.; Prager, S.C.

    1993-02-01

    The fluctuation induced Hall term, {le}{approximately}{ovr J} {times} {approximately}{ovr B}{ge}, has been measured in the MST reversed field pinch. The term is of interest as a possible source of current self-generation (dynamo). It is found to be non-negligible, but small in that it can account for less than 25% of the dynamo driven current.

  15. Henderson Hall's Education and Career Fair

    Broader source: Energy.gov [DOE]

    Location: Smith Gym, Henderson Hall, Arlington, VAPOC: Donna FriendWebsite: http://www.mccshh.com/EducationCareerFairFall2014.html

  16. Building Green in Greensburg: City Hall Building

    Broader source: Energy.gov [DOE]

    This poster highlights energy efficiency, renewable energy, and sustainable features of the high-performing City Hall building in Greensburg, Kansas.

  17. Rebuilding It Better: Greensburg, Kansas, City Hall

    SciTech Connect (OSTI)

    D. Egan

    2010-04-13

    This document showcases the LEED-Platinum designed Greensburg City Hall, which was rebuilt green, after a massive tornado destroyed Greensburg, Kansas in May 2007.

  18. Hall-effect arc protector

    DOE Patents [OSTI]

    Rankin, R.A.; Kotter, D.K.

    1997-05-13

    The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored. 2 figs.

  19. Portland State University Shattuck Hall

    High Performance Buildings Database

    Portland, OR Portland State's Shattuck hall was originally constructed as an elementary school in 1915. In 2007 the university undertook extensive renovations of the building to bring it up to current seismic requirements. In addition to structural improvements, the design team was able to upgraded the building's aging mechanical and electrical systems, upgrade plumbing, and restore the large light wells that bring daylight into the U-shaped building. The resulting building houses Portland State's Architecture department, where students are able to learn from the exposed building systems.

  20. Hall-effect arc protector

    DOE Patents [OSTI]

    Rankin, Richard A.; Kotter, Dale K.

    1997-01-01

    The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored.

  1. Town Hall with Secretary Moniz

    SciTech Connect (OSTI)

    Energy Secretary Ernest Moniz; Deputy Secretary of Energy Daniel Poneman

    2013-07-18

    In a town hall meeting with Department staff, Energy Secretary Ernest Moniz spoke about his plans for a reorganization of the Energy Department’s management structure. The plans will help better achieve the Department’s key priorities and those of the President, including implementing the President’s Climate Action Plan, “all of the above” energy strategy and nuclear security agenda. After his remarks, Moniz, joined by Deputy Secretary Dan Poneman, took questions from the audience in the Forrestal Auditorium as well as email questions from other Department locations.

  2. Town Hall with Secretary Moniz

    ScienceCinema (OSTI)

    Energy Secretary Ernest Moniz; Deputy Secretary of Energy Daniel Poneman

    2013-07-25

    In a town hall meeting with Department staff, Energy Secretary Ernest Moniz spoke about his plans for a reorganization of the Energy Department?s management structure. The plans will help better achieve the Department?s key priorities and those of the President, including implementing the President?s Climate Action Plan, ?all of the above? energy strategy and nuclear security agenda. After his remarks, Moniz, joined by Deputy Secretary Dan Poneman, took questions from the audience in the Forrestal Auditorium as well as email questions from other Department locations.

  3. Reduced spin-Hall effects from magnetic proximity (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Reduced spin-Hall effects from magnetic proximity Prev Next Title: Reduced spin-Hall effects from magnetic proximity Authors: Zhang, Wei ; Jungfleisch, Matthias B. ; Jiang, ...

  4. Charge carrier coherence and Hall effect in organic semiconductors...

    Office of Scientific and Technical Information (OSTI)

    Charge carrier coherence and Hall effect in organic semiconductors Citation Details In-Document Search Title: Charge carrier coherence and Hall effect in organic semiconductors ...

  5. Quantum Hall effects in a Weyl semimetal: Possible application...

    Office of Scientific and Technical Information (OSTI)

    Quantum Hall effects in a Weyl semimetal: Possible application in pyrochlore iridates Title: Quantum Hall effects in a Weyl semimetal: Possible application in pyrochlore iridates ...

  6. Microscopic theory of quantum anomalous Hall effect in graphene...

    Office of Scientific and Technical Information (OSTI)

    Microscopic theory of quantum anomalous Hall effect in graphene Citation Details In-Document Search Title: Microscopic theory of quantum anomalous Hall effect in graphene Authors: ...

  7. Hall County, Texas: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    B. Places in Hall County, Texas Estelline, Texas Lakeview, Texas Memphis, Texas Turkey, Texas Retrieved from "http:en.openei.orgwindex.php?titleHallCounty,Texas&oldid...

  8. Topological Hubbard Model and Its High-Temperature Quantum Hall...

    Office of Scientific and Technical Information (OSTI)

    Topological Hubbard Model and Its High-Temperature Quantum Hall Effect Title: Topological Hubbard Model and Its High-Temperature Quantum Hall Effect Authors: Neupert, Titus ; ...

  9. Data acquisition system of Moeller polarimeter Hall A Jefferson...

    Office of Scientific and Technical Information (OSTI)

    Data acquisition system of Moeller polarimeter Hall A Jefferson Lab (in Russian) Citation Details In-Document Search Title: Data acquisition system of Moeller polarimeter Hall A ...

  10. Building America Top Innovations Hall of Fame Profile - Building...

    Energy Savers [EERE]

    Building America Top Innovations Hall of Fame Profile - Building Energy Optimization Analysis Method (BEopt) Building America Top Innovations Hall of Fame Profile - Building Energy...

  11. The quantum Hall effect helicity

    SciTech Connect (OSTI)

    Shrivastava, Keshav N.

    2015-04-16

    The quantum Hall effect in semiconductor heterostructures is explained by two signs in the angular momentum j=l±s and g=(2j+1)/(2l+1) along with the Landau factor (n+1/2). These modifications in the existing theories explain all of the fractional charges. The helicity which is the sign of the product of the linear momentum with the spin p.s plays an important role for the understanding of the data at high magnetic fields. In particular it is found that particles with positive sign in the spin move in one direction and those with negative sign move in another direction which explains the up and down stream motion of the particles.

  12. Experiment Hall & Beamline | Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1104-m-circumference optical bench. The hall floor is made of 1-ft-thick poured concrete. Usual practice in poured concrete construction is the use of evenly spaced cuts in...

  13. OpenEI Community - Town Hall meeting

    Open Energy Info (EERE)

    st, 2012 http:en.openei.orgcommunityblogtown-hall-meeting-october-1st-2012

  14. OSDBU Federal Contracting Town Hall Meeting

    Office of Energy Efficiency and Renewable Energy (EERE)

    In June of 2015, John Hale III, Director of the Office of Small and Disadvantaged Business Utilization, served as the moderator for the Federal Contracting Town Hall Meeting during the CelebrAsian...

  15. Manhattan Project: Fuller Lodge

    Office of Scientific and Technical Information (OSTI)

    Fuller Lodge was one of the main structures of the Los Alamos Boys Ranch School, serving as its headquarters in its later years. It was converted into a mess hall and guest ...

  16. DOE2016 Exhibit Hall | Department of Energy

    Energy Savers [EERE]

    Exhibit Hall DOE2016 Exhibit Hall Addthis 1 of 25 2 of 25 3 of 25 4 of 25 5 of 25 6 of 25 7 of 25 8 of 25 9 of 25 10 of 25 11 of 25 12 of 25 13 of 25 14 of 25 15 of 25 16 of 25 17 of 25 18 of 25 19 of 25 20 of 25 21 of 25 22 of 25 23 of 25 24 of 25 25 of 25

  17. Hypernuclei in Hall C | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hypernuclei in Hall C Hypernuclei in Hall C High Resolution Electron Spectrometer The High Resolution Electron Spectrometer (teal and red, top left) was recently built with a grant from Japan's Ministry of Education, Culture, Sports, Science and Technology. The ministry also funded the new splitter magnet (dark green) and the High Resolution Kaon Spectrometer (purple and light green, top right). Nuclear scientists have gone to great lengths to pry open the nucleus and peer deep inside. They've

  18. Forest County Potawatomi Community Parking Ramp and Wundar Hall...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... into Trust in 1990 The Tribe has been leasing to a long-term tenant whose lease will end in July 2010 Wundar Hall Project Wundar Hall is a 34,000 sq ft dormitory building ...

  19. TBB-0042- In the Matter of Curtis Hall

    Broader source: Energy.gov [DOE]

    This letter concerns the complaint of retaliation filed by Curtis Hall (the complainant or Mr. Hall) with the Department of Energy under 10 C . F. R. Part 7 0 8 , the DOE Con tractor Employee ...

  20. Phase transitions in quantum Hall multiple layer systems

    SciTech Connect (OSTI)

    Pusep, Yu A.; Fernandes dos Santos, L.; Smirnov, D.; Bakarov, A. K.; Toropov, A. I.

    2013-12-04

    Polarized photoluminescence from multiple well electron systems was studied in the regime of the integer quantum Hall effect. Two quantum Hall ferromagnetic ground states assigned to the uncorrelated miniband quantum Hall state and to the spontaneous interwell phase coherent dimer quantum Hall state were observed. The photoluminescence associated with these states exhibits features caused by finite-size skyrmions. The depolarization of the ferromagnetic ground state was observed in bilayer system.

  1. Diversity and Inclusion Town Hall Program Book | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Town Hall Program Book Diversity and Inclusion Town Hall Program Book As part of a larger effort to create a culture that values diversity, we have been conducting focus groups to engage in a dialog and hear feedback on how diversity can be improved. At the Town Hall, DOE employees will hear the results of these discussions. View the program booklet from the Diversity and Inclusion Town Hall below. For more information about the Department's diversity and inclusion programs, visit

  2. Spring 2015 Henderson Hall Education and Career Fair

    Office of Energy Efficiency and Renewable Energy (EERE)

    Location: Smith Gym, Henderson Hall, Arlington, VAPOC: DOECorporateRecruitment@hq.doe.govWebsite: http://bit.ly/1FRIJOF

  3. Effective Field Theory of Fractional Quantized Hall Nematics (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Effective Field Theory of Fractional Quantized Hall Nematics Citation Details In-Document Search Title: Effective Field Theory of Fractional Quantized Hall Nematics We present a Landau-Ginzburg theory for a fractional quantized Hall nematic state and the transition to it from an isotropic fractional quantum Hall state. This justifies Lifshitz-Chern-Simons theory - which is shown to be its dual - on a more microscopic basis and enables us to compute a ground state

  4. Parametric Investigations of Non-Conventional Hall Thruster

    SciTech Connect (OSTI)

    Raitses, Y.; Fisch, N.J.

    2001-01-12

    Hall thrusters might better scale to low power with non-conventional geometry. A 9 cm cylindrical, ceramic-channel, Hall thruster with a cusp-type magnetic field distribution has been investigated. It exhibits discharge characteristics similar to conventional coaxial Hall thrusters, but does not expose as much channel surface. Significantly, its operation is not accompanied by large amplitude discharge low frequency oscillations.

  5. Newmark-Hall synthetic history development

    SciTech Connect (OSTI)

    Aramayo, G.A.

    1990-11-01

    The methodology used to develop synthetic acceleration time histories with spectral content that envelopes the Newmark-Hall spectra is described. Six acceleration time histories are developed for two conditions of foundation and 3 critical damping factors. The target spectra corresponds to the mediam centered probability level.

  6. Moderate positive spin Hall angle in uranium

    SciTech Connect (OSTI)

    Singh, Simranjeet; Anguera, Marta; Barco, Enrique del E-mail: cwmsch@rit.edu; Springell, Ross; Miller, Casey W. E-mail: cwmsch@rit.edu

    2015-12-07

    We report measurements of spin pumping and the inverse spin Hall effect in Ni{sub 80}Fe{sub 20}/uranium bilayers designed to study the efficiency of spin-charge interconversion in a super-heavy element. We employ broad-band ferromagnetic resonance on extended films to inject a spin current from the Ni{sub 80}Fe{sub 20} (permalloy) into the uranium layer, which is then converted into an electric field by the inverse spin Hall effect. Surprisingly, our results suggest a spin mixing conductance of order 2 × 10{sup 19} m{sup −2} and a positive spin Hall angle of 0.004, which are both merely comparable with those of several transition metals. These results thus support the idea that the electronic configuration may be at least as important as the atomic number in governing spin pumping across interfaces and subsequent spin Hall effects. In fact, given that both the magnitude and the sign are unexpected based on trends in d-electron systems, materials with unfilled f-electron orbitals may hold additional exploration avenues for spin physics.

  7. Comparison of Secondary Islands in Collisional Reconnection to Hall Reconnection

    SciTech Connect (OSTI)

    Shepherd, L. S.; Cassak, P. A.

    2010-07-02

    Large-scale resistive Hall-magnetohydrodynamic simulations of the transition from Sweet-Parker (collisional) to Hall (collisionless) magnetic reconnection are presented; the first to separate secondary islands from collisionless effects. Three main results are described. There exists a regime with secondary islands but without collisionless effects, and the reconnection rate is faster than Sweet-Parker, but significantly slower than Hall reconnection. This implies that secondary islands do not cause the fastest reconnection rates. The onset of Hall reconnection ejects secondary islands from the vicinity of the X line, implying that energy is released more rapidly during Hall reconnection. Coronal applications are discussed.

  8. Fast Camera Imaging of Hall Thruster Ignition

    SciTech Connect (OSTI)

    C.L. Ellison, Y. Raitses and N.J. Fisch

    2011-02-24

    Hall thrusters provide efficient space propulsion by electrostatic acceleration of ions. Rotating electron clouds in the thruster overcome the space charge limitations of other methods. Images of the thruster startup, taken with a fast camera, reveal a bright ionization period which settles into steady state operation over 50 μs. The cathode introduces azimuthal asymmetry, which persists for about 30 μs into the ignition. Plasma thrusters are used on satellites for repositioning, orbit correction and drag compensation. The advantage of plasma thrusters over conventional chemical thrusters is that the exhaust energies are not limited by chemical energy to about an electron volt. For xenon Hall thrusters, the ion exhaust velocity can be 15-20 km/s, compared to 5 km/s for a typical chemical thruster

  9. The Honorable,Edward Rendell, '. City Hall

    Office of Legacy Management (LM)

    I:! i394 .\ . The Honorable,Edward Rendell, '. City Hall Philadelphia, Pennsylvania 19107 Dear Mayor Rendell : ', ,' . , Secretary of Energy Hazel O',teary has announced-a new approach.to.openness in the Department of Energy (DDE) and its communications with the public. . In support of this initiative, we are.pleased to forward the enclosed information related to the,former. Penn Salt Manufacturing' Co. site in your jurisdiction that performed.work for DOE or its predecessor agencies. This

  10. Town_Hall_Meeting_10_29_15.pdf

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Town Hall with Secretary Moniz Town Hall with Secretary Moniz July 18, 2013 - 3:42pm Addthis Secretary Moniz speaks at a townhall with DOE employees on the Departmental reorganization. Dan Leistikow Dan Leistikow Former Director, Office of Public Affairs In a town hall meeting with Department staff, Energy Secretary Ernest Moniz spoke about his plans for a reorganization of the Energy Department's management structure. The plans will help better achieve the Department's key priorities and those

  11. Webcast: National Energy Literacy Virtual Town Hall | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Webcast: National Energy Literacy Virtual Town Hall Webcast: National Energy Literacy Virtual Town Hall Webcast: National Energy Literacy Virtual Town Hall On August 5, 2014, the Department of Energy (DOE) hosted a dynamic virtual conversation of ongoing efforts from across the country in utilizing the Energy Literacy Framework to address one of our nations' biggest national challenges, "Energy Illiteracy." The goal of this webinar was to share resources in energy education and provide

  12. Missed Today's Town Hall with Sec. Chu? | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Missed Today's Town Hall with Sec. Chu? Missed Today's Town Hall with Sec. Chu? January 26, 2011 - 4:02pm Addthis We have the video of today's online town hall event with Secretary Chu up and ready for your viewing. Check it out here. Ginny Simmons Ginny Simmons Former Managing Editor for Energy.gov, Office of Public Affairs We have the video of today's online town hall event with Secretary Chu up and ready for your viewing. Check it out here. During the event, Secretary Chu highlighted several

  13. Lecture & Dining Halls - Combustion Energy Frontier Research Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lecture & Dining Halls Lecture & Dining Halls Lecture Halls: Friend Center SeeSchedule of Events for schedule and location of lectures. How far are the lecture halls from the dormitories? Friend Center is a quick 10 minute walk from the Butler dormitories. See campus map for walking directions. There is also a free campus shuttle that will take you from outside the Icahn Lab on Washington Road to the Friend Center. See http://www.princeton.edu/transportation/ttroutes/ for shuttle times.

  14. Hall's Warehouse Corp Solar Project | Open Energy Information

    Open Energy Info (EERE)

    Corp. Solar Project" Retrieved from "http:en.openei.orgwindex.php?titleHall%27sWarehouseCorpSolarProject&oldid397541" Feedback Contact needs updating Image...

  15. Building America Top Innovations Hall of Fame Profile … High...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... TOP INNOVATIONS BUILDING AMERICA BUILDING AMERICA TOP INNOVATIONS HALL OF FAME PROFILE Habitat affiliates across the country held "blitz builds" to construct homes for Gulf Coast ...

  16. Rebuilding It Better: Greensburg, Kansas. City Hall (Brochure)

    SciTech Connect (OSTI)

    Not Available

    2010-04-01

    This document showcases the LEED-Platinum designed Greensburg City Hall, which was rebuilt green, after a massive tornado destroyed Greensburg, Kansas in May 2007.

  17. Building America Top Innovations Hall of Fame Profile - Building...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Building America Top Innovations Hall of Fame Profile - Building America's Top Innovations Propel the Home Building Industry toward Higher Performance Building America Top ...

  18. Charge carrier coherence and Hall effect in organic semiconductors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yi, H. T.; Gartstein, Y. N.; Podzorov, V.

    2016-03-30

    Hall effect measurements are important for elucidating the fundamental charge transport mechanisms and intrinsic mobility in organic semiconductors. However, Hall effect studies frequently reveal an unconventional behavior that cannot be readily explained with the simple band-semiconductor Hall effect model. Here, we develop an analytical model of Hall effect in organic field-effect transistors in a regime of coexisting band and hopping carriers. The model, which is supported by the experiments, is based on a partial Hall voltage compensation effect, occurring because hopping carriers respond to the transverse Hall electric field and drift in the direction opposite to the Lorentz force actingmore » on band carriers. We show that this can lead in particular to an underdeveloped Hall effect observed in organic semiconductors with substantial off-diagonal thermal disorder. Lastly, our model captures the main features of Hall effect in a variety of organic semiconductors and provides an analytical description of Hall mobility, carrier density and carrier coherence factor.« less

  19. Systems and Methods for Cylindrical Hall Thrusters with Independently...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Systems and Methods for Cylindrical Hall Thrusters with Independently Controllable Ionization and Acceleration Stages Yevgeny Raitses, Nathaniel J. Fisch and Kevin D. Diamant (The...

  20. Anomalous spin precession and spin Hall effect in semiconductor...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Anomalous spin precession and spin Hall effect in semiconductor quantum wells Citation Details In-Document Search Title: Anomalous ...

  1. Robert B. Laughlin and the Fractional Quantum Hall Effect

    Office of Scientific and Technical Information (OSTI)

    Robert B. Laughlin and the Fractional Quantum Hall Effect Resources with Additional Information Robert B. Laughlin Photo Courtesy of LLNL Robert B. Laughlin shared the 1998 Nobel...

  2. Centre Hall, Pennsylvania: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Hall, Pennsylvania: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 40.8475635, -77.6861093 Show Map Loading map... "minzoom":false,"mappingser...

  3. Hall County, Georgia: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Hall County, Georgia: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 34.30778, -83.804868 Show Map Loading map... "minzoom":false,"mappingserv...

  4. Rebuilding It Better: Greensburg, Kansas. City Hall (Brochure)

    Broader source: Energy.gov [DOE]

    This brochure details the energy efficient and sustainable aspects of the LEED Platinum-designated City Hall building in Greensburg, Kansas.

  5. Town Hall with Secretary Moniz | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Secretary Moniz speaks at a townhall with DOE employees on the Departmental ... In a town hall meeting with Department staff, Energy Secretary Ernest Moniz spoke about ...

  6. Robert B. Laughlin and the Fractional Quantum Hall Effect

    Office of Scientific and Technical Information (OSTI)

    In 1983, Laughlin, then at the Lawrence Livermore National Laboratory, provided the ... quantum Hall effect.'1 ' "My presence at Livermore was crucial to my work," says Laughlin. ...

  7. Rebuilding It Better: Greensburg, Kansas, City Hall (Brochure)

    SciTech Connect (OSTI)

    Not Available

    2010-09-01

    This brochure details the energy efficient and sustainable aspects of the LEED Platinum-designated City Hall building in Greensburg, Kansas.

  8. Synchronization of spin-transfer torque oscillators by spin pumping, inverse spin Hall, and spin Hall effects

    SciTech Connect (OSTI)

    Elyasi, Mehrdad; Bhatia, Charanjit S.; Yang, Hyunsoo

    2015-02-14

    We have proposed a method to synchronize multiple spin-transfer torque oscillators based on spin pumping, inverse spin Hall, and spin Hall effects. The proposed oscillator system consists of a series of nano-magnets in junction with a normal metal with high spin-orbit coupling, and an accumulative feedback loop. We conduct simulations to demonstrate the effect of modulated charge currents in the normal metal due to spin pumping from each nano-magnet. We show that the interplay between the spin Hall effect and inverse spin Hall effect results in synchronization of the nano-magnets.

  9. Lees-Kubota Lecture Hall, Guggenheim 101

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    SPECIAL SEMINAR - Monday, November 3 rd Lees-Kubota Lecture Hall, Guggenheim 101 11:15am-12:15pm "Perovskite Solar Cells: Towards New Materials and New Applications" Professor Nripan Mathews Nanyang Technological University, Singapore Abstract: Perovskite solar cells have attracted a lot of attention primarily due to its high efficiency (~19%). Much of the attention has focused on CH 3 NH 3 PbI 3 (Eg-1.55eV) whose high performance can be traced to a high absorption coefficient as well

  10. Segmented electrode hall thruster with reduced plume

    DOE Patents [OSTI]

    Fisch, Nathaniel J.; Raitses, Yevgeny

    2004-08-17

    An apparatus and method for thrusting plasma, utilizing a Hall thruster with segmented electrodes along the channel, which make the acceleration region as localized as possible. Also disclosed are methods of arranging the electrodes so as to minimize erosion and arcing. Also disclosed are methods of arranging the electrodes so as to produce a substantial reduction in plume divergence. The use of electrodes made of emissive material will reduce the radial potential drop within the channel, further decreasing the plume divergence. Also disclosed is a method of arranging and powering these electrodes so as to provide variable mode operation.

  11. Halls Middle School students get a taste of science at Y-12 ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Halls Middle School ... Halls Middle School students get a taste of science at Y-12 Posted: May 21, 2013 - 12:40pm Engineering, science and history experts give Halls Middle School...

  12. Cylindrical Hall Thrusters with Permanent Magnets

    SciTech Connect (OSTI)

    Raitses, Yevgeny; Merino, Enrique; Fisch, Nathaniel J.

    2010-10-18

    The use of permanent magnets instead of electromagnet coils for low power Hall thrusters can offer a significant reduction of both the total electric power consumption and the thruster mass. Two permanent magnet versions of the miniaturized cylindrical Hall thruster (CHT) of different overall dimensions were operated in the power range of 50W-300 W. The discharge and plasma plume measurements revealed that the CHT thrusters with permanent magnets and electromagnet coils operate rather differently. In particular, the angular ion current density distribution from the permanent magnet thrusters has an unusual halo shape, with a majority of high energy ions flowing at large angles with respect to the thruster centerline. Differences in the magnetic field topology outside the thruster channel and in the vicinity of the channel exit are likely responsible for the differences in the plume characteristics measured for the CHTs with electromagnets and permanent magnets. It is shown that the presence of the reversing-direction or cusp-type magnetic field configuration inside the thruster channel without a strong axial magnetic field outside the thruster channel does not lead to the halo plasma plume from the CHT. __________________________________________________

  13. Undulator Hall Air Temperature Fault Scenarios

    SciTech Connect (OSTI)

    Sevilla, J.; Welch, J.; ,

    2010-11-17

    Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about {+-}2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.

  14. Pair spectrometer hodoscope for Hall D at Jefferson Lab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barbosa, Fernando J.; Hutton, Charles L.; Sitnikov, Alexandre; Somov, Alexander S.; Somov, S.; Tolstukhin, Ivan

    2015-09-21

    We present the design of the pair spectrometer hodoscope fabricated at Jefferson Lab and installed in the experimental Hall D. The hodoscope consists of thin scintillator tiles; the light from each tile is collected using wave-length shifting fibers and detected using a Hamamatsu silicon photomultiplier. Light collection was measured using relativistic electrons produced in the tagger area of the experimental Hall B.

  15. Energy spectrum, dissipation, and spatial structures in reduced Hall magnetohydrodynamic

    SciTech Connect (OSTI)

    Martin, L. N.; Dmitruk, P.; Gomez, D. O.

    2012-05-15

    We analyze the effect of the Hall term in the magnetohydrodynamic turbulence under a strong externally supported magnetic field, seeing how this changes the energy cascade, the characteristic scales of the flow, and the dynamics of global magnitudes, with particular interest in the dissipation. Numerical simulations of freely evolving three-dimensional reduced magnetohydrodynamics are performed, for different values of the Hall parameter (the ratio of the ion skin depth to the macroscopic scale of the turbulence) controlling the impact of the Hall term. The Hall effect modifies the transfer of energy across scales, slowing down the transfer of energy from the large scales up to the Hall scale (ion skin depth) and carrying faster the energy from the Hall scale to smaller scales. The final outcome is an effective shift of the dissipation scale to larger scales but also a development of smaller scales. Current sheets (fundamental structures for energy dissipation) are affected in two ways by increasing the Hall effect, with a widening but at the same time generating an internal structure within them. In the case where the Hall term is sufficiently intense, the current sheet is fully delocalized. The effect appears to reduce impulsive effects in the flow, making it less intermittent.

  16. Non-abelian fractional quantum hall effect for fault-resistant...

    Office of Scientific and Technical Information (OSTI)

    Non-abelian fractional quantum hall effect for fault-resistant topological quantum computation. Citation Details In-Document Search Title: Non-abelian fractional quantum hall...

  17. WIPP Employee Inducted Into Mine Rescue Hall of Fame - WIPP Teams...

    Office of Environmental Management (EM)

    Employee Inducted Into Mine Rescue Hall of Fame - WIPP Teams Recognized at National Competition WIPP Employee Inducted Into Mine Rescue Hall of Fame - WIPP Teams Recognized at ...

  18. Fractional Quantum Hall Effect at Landau Level Filling v=4/11...

    Office of Scientific and Technical Information (OSTI)

    Fractional Quantum Hall Effect at Landau Level Filling v411. Citation Details In-Document Search Title: Fractional Quantum Hall Effect at Landau Level Filling v411. Abstract...

  19. Anomalous Hall effect in YIG|Pt bilayers

    SciTech Connect (OSTI)

    Meyer, Sibylle Schlitz, Richard; Geprägs, Stephan; Opel, Matthias; Huebl, Hans; Goennenwein, Sebastian T. B.; Gross, Rudolf

    2015-03-30

    We measure the ordinary and the anomalous Hall effect in a set of yttrium iron garnet|platinum (YIG|Pt) bilayers via magnetization orientation dependent magnetoresistance experiments. Our data show that the presence of the ferrimagnetic insulator YIG leads to an anomalous Hall effect like voltage in Pt, which is sensitive to both Pt thickness and temperature. Interpretation of the experimental findings in terms of the spin Hall anomalous Hall effect indicates that the imaginary part of the spin mixing conductance G{sub i} plays a crucial role in YIG|Pt bilayers. In particular, our data suggest a sign change in G{sub i} between 10 K and 300 K. Additionally, we report a higher order Hall effect contribution, which appears in thin Pt films on YIG at low temperatures.

  20. Spin Hall magnetoresistance at high temperatures

    SciTech Connect (OSTI)

    Uchida, Ken-ichi; Qiu, Zhiyong; Kikkawa, Takashi; Iguchi, Ryo; Saitoh, Eiji

    2015-02-02

    The temperature dependence of spin Hall magnetoresistance (SMR) in Pt/Y{sub 3}Fe{sub 5}O{sub 12} (YIG) bilayer films has been investigated in a high temperature range from room temperature to near the Curie temperature of YIG. The experimental results show that the magnitude of the magnetoresistance ratio induced by the SMR monotonically decreases with increasing the temperature and almost disappears near the Curie temperature. We found that, near the Curie temperature, the temperature dependence of the SMR in the Pt/YIG film is steeper than that of a magnetization curve of the YIG; the critical exponent of the magnetoresistance ratio is estimated to be 0.9. This critical behavior of the SMR is attributed mainly to the temperature dependence of the spin-mixing conductance at the Pt/YIG interface.

  1. Stacking order dependence of inverse spin Hall effect and anomalous Hall effect in spin pumping experiments

    SciTech Connect (OSTI)

    Kim, Sang-Il; Seo, Min-Su; Park, Seung-Young; Kim, Dong-Jun; Park, Byong-Guk

    2015-05-07

    The dependence of the measured DC voltage on the non-magnetic material (NM) in NM/CoFeB and CoFeB/NM bilayers is studied under ferromagnetic resonance conditions in a TE{sub 011} resonant cavity. The directional change of the inverse spin Hall effect (ISHE) voltage V{sub ISHE} for the stacking order of the bilayer can separate the pure V{sub ISHE} and the anomalous Hall effect (AHE) voltage V{sub AHE} utilizing the method of addition and subtraction. The Ta and Ti NMs show a broad deviation of the spin Hall angle θ{sub ISH}, which originates from the AHE in accordance with the high resistivity of NMs. However, the Pt and Pd NMs show that the kinds of NMs with low resistivity are consistent with the previously reported θ{sub ISH} values. Therefore, the characteristics that NM should simultaneously satisfy to obtain a reasonable V{sub ISHE} value in bilayer systems are large θ{sub ISH} and low resistivity.

  2. Parametric Investigations of Miniaturized Cylindrical and Annular Hall Thrusters

    SciTech Connect (OSTI)

    A. Smirnov; Y. Raitses; N.J. Fisch

    2001-10-16

    A cylindrical geometry Hall thruster may overcome certain physical and technological limitations in scaling down of Hall thrusters to miniature sizes. The absence of the inner wall and use of the cusp magnetic field can potentially reduce heating of the thruster parts and erosion of the channel. A 2.6 cm miniaturized Hall thruster of a flexible design was built and successfully operated in the power range of 50-300 W. Comparison of preliminary results obtained for cylindrical and annular thruster configurations is presented.

  3. Notify Work Coordinators Before Working in/Entering Halls | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Notify Work Coordinators Before Working in/Entering Halls Remember to Notify Work Coordinators Before Working in/Entering Hall A, B, C & D The Worker Safety Committee reminds all members of the Jefferson Lab community that they must notify the appropriate experimental hall Work Coordinator (WC) - for Hall A, B, C or D - in advance of doing any work in that hall or in advance of taking any materials or equipment into or out of that hall. Hall Work Coordinators ask to be notified by phone call

  4. Property:Building/FloorAreaTheatresConcertHallsCinemas | Open...

    Open Energy Info (EERE)

    Property Edit with form History Property:BuildingFloorAreaTheatresConcertHallsCinemas Jump to: navigation, search This is a property of type Number. Floor area for Theatres,...

  5. SubTER Presentation at Town Hall- American Geophysical Union

    Broader source: Energy.gov [DOE]

    Subter, the Subsurface Crosscut at the Energy Department, conducted a Town Hall meeting to share information and create a dialogue regarding the grand challenges of energy production and storage in the subsurface.

  6. Charge carrier coherence and Hall effect in organic semiconductors

    Office of Scientific and Technical Information (OSTI)

    OPEN: Charge carrier coherence and Hall effect in organic semiconductors H. T. Yi1, Y. N. Gartstein2 & V. Podzorov1-3 Received: 21 January 2016 Accepted: 29 February 2016 ...

  7. Hall County, Nebraska: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Hide Map This article is a stub. You can help OpenEI by expanding it. Hall County is a county in Nebraska. Its FIPS County Code is 079. It is classified as ASHRAE...

  8. Building America Top Innovations Hall of Fame Profile … EEBA...

    Energy Savers [EERE]

    ... TOP INNOVATIONS BUILDING AMERICA BUILDING AMERICA TOP INNOVATIONS HALL OF FAME PROFILE The ... Drain all water away from the structure The secret to water management is to construct the ...

  9. Building America Top Innovations Hall of Fame Profile - Building

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    America's Top Innovations Propel the Home Building Industry toward Higher Performance | Department of Energy Building America Top Innovations Hall of Fame Profile - Building America's Top Innovations Propel the Home Building Industry toward Higher Performance Building America Top Innovations Hall of Fame Profile - Building America's Top Innovations Propel the Home Building Industry toward Higher Performance This Building America Innovations profile describes the concept for the U.S.

  10. Hall effect measurements on InAs nanowires

    SciTech Connect (OSTI)

    Bloemers, Ch.; Grap, T.; Lepsa, M. I.; Moers, J.; Gruetzmacher, D.; Lueth, H.; Trellenkamp, St.; Schaepers, Th.

    2012-10-08

    We have processed Hall contacts on InAs nanowires grown by molecular beam epitaxy using an electron beam lithography process with an extremely high alignment accuracy. The carrier concentrations determined from the Hall effect measurements on these nanowires are lower by a factor of about 4 in comparison with those measured by the common field-effect technique. The results are used to evaluate quantitatively the charging effect of the interface and surface states.

  11. Public invited to LANL-sponsored Energy Town Hall

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Day event showcases LANL energy work April 19, 2010 Public invited to LANL-sponsored Energy Town Hall April 21 at the J. Robert Oppenheimer Study Center LOS ALAMOS, New Mexico, April 19, 2010-The public is invited to learn about projects in energy conservation, generation, research, and management at an Energy Town Hall April 21. Other energy-related issues, such as server virtualization, solar energy, and Los Alamos National Laboratory's perspective on renewable energy, also will be explored in

  12. Exact solutions of the incompressible dissipative Hall magnetohydrodynamics

    SciTech Connect (OSTI)

    Xia, Zhenwei; Yang, Weihong

    2015-03-15

    By using analytical method, the exact solutions of the incompressible dissipative Hall magnetohydrodynamics (MHD) equations are derived. It is found that a phase difference may occur between the velocity and magnetic field fluctuations when the kinetic and magnetic Reynolds numbers are both very large. Since velocity and magnetic field fluctuations are both circular polarized, the phase difference makes them no longer parallel or anti-parallel like that in the incompressible ideal Hall MHD.

  13. Magnetometry of micro-magnets with electrostatically defined Hall bars

    SciTech Connect (OSTI)

    Lachance-Quirion, Dany; Camirand Lemyre, Julien; Bergeron, Laurent; Sarra-Bournet, Christian; Pioro-Ladrière, Michel

    2015-11-30

    Micro-magnets are key components for quantum information processing with individual spins, enabling arbitrary rotations and addressability. In this work, characterization of sub-micrometer sized CoFe ferromagnets is performed with Hall bars electrostatically defined in a two-dimensional electron gas. Due to the ballistic nature of electron transport in the cross junction of the Hall bar, anomalies such as the quenched Hall effect appear near zero external magnetic field, thus hindering the sensitivity of the magnetometer to small magnetic fields. However, it is shown that the sensitivity of the diffusive limit can be almost completely restored at low temperatures using a large current density in the Hall bar of about 10 A/m. Overcoming the size limitation of conventional etched Hall bars with electrostatic gating enables the measurement of magnetization curves of 440 nm wide micro-magnets with a signal-to-noise ratio above 10{sup 3}. Furthermore, the inhomogeneity of the stray magnetic field created by the micro-magnets is directly measured using the gate-voltage-dependent width of the sensitive area of the Hall bar.

  14. Stability of Hall equilibria in neutron star crusts

    SciTech Connect (OSTI)

    Marchant, Pablo; Reisenegger, Andreas; Valdivia, Juan Alejandro; Hoyos, Jaime H.

    2014-12-01

    In the solid crusts of neutron stars, the advection of the magnetic field by the current-carrying electrons, an effect known as Hall drift, should play a very important role as the ions remain essentially fixed (as long as the solid does not break). Although Hall drift preserves the magnetic field energy, it has been argued that it may drive a turbulent cascade to scales at which ohmic dissipation becomes effective, allowing a much faster decay in objects with very strong fields. On the other hand, it has been found that there are 'Hall equilibria', i.e., field configurations that are unaffected by Hall drift. Here we address the crucial question of the stability of these equilibria through axially symmetric (two-dimensional (2D)) numerical simulations of Hall drift and ohmic diffusion, with the simplifying assumption of uniform electron density and conductivity. We demonstrate the 2D stability of a purely poloidal equilibrium, for which ohmic dissipation makes the field evolve toward an attractor state through adjacent stable configurations, around which damped oscillations occur. For this field, the decay scales with the ohmic timescale. We also study the case of an unstable equilibrium consisting of both poloidal and toroidal field components that are confined within the crust. This field evolves into a stable configuration, which undergoes damped oscillations superimposed on a slow evolution toward an attractor, just as the purely poloidal one.

  15. Optical detection of spin Hall effect in metals

    SciTech Connect (OSTI)

    Erve, O. M. J. van ‘t Hanbicki, A. T.; McCreary, K. M.; Li, C. H.; Jonker, B. T.

    2014-04-28

    Optical techniques have been widely used to probe the spin Hall effect in semiconductors. In metals, however, only electrical methods such as nonlocal spin valve transport, ferromagnetic resonance, or spin torque transfer experiments have been successful. These methods require complex processing techniques and measuring setups. We show here that the spin Hall effect can be observed in non-magnetic metals such as Pt and β-W, using a standard bench top magneto-optical Kerr system with very little sample preparation. Applying a square wave current and using Fourier analysis significantly improve our detection level. One can readily determine the angular dependence of the induced polarization on the bias current direction (very difficult to do with voltage detection), the orientation of the spin Hall induced polarization, and the sign of the spin Hall angle. This optical approach is free from the complications of various resistive effects, which can compromise voltage measurements. This opens up the study of spin Hall effect in metals to a variety of spin dynamic and spatial imaging experiments.

  16. Reconnection dynamics with secondary tearing instability in compressible Hall plasmas

    SciTech Connect (OSTI)

    Ma, Z. W. Wang, L. C.; Li, L. J.

    2015-06-15

    The dynamics of a secondary tearing instability is systematically investigated based on compressible Hall magnetohydrodynamic. It is found that in the early nonlinear phase of magnetic reconnection before onset of the secondary tearing instability, the geometry of the magnetic field in the reconnection region tends to form a Y-type structure in a weak Hall regime, instead of an X-type structure in a strong Hall regime. A new scaling law is found that the maximum reconnection rate in the early nonlinear stage is proportional to the square of the ion inertial length (γ∝d{sub i}{sup 2}) in the weak Hall regime. In the late nonlinear phase, the thin elongated current sheet associated with the Y-type geometry of the magnetic field breaks up to form a magnetic island due to a secondary tearing instability. After the onset of the secondary tearing mode, the reconnection rate is substantially boosted by the formation of the X-type geometries of magnetic field in the reconnection regions. With a strong Hall effect, the maximum reconnection rate linearly increases with the increase of the ion inertial length (γ∝d{sub i})

  17. Reconnection events in two-dimensional Hall magnetohydrodynamic turbulence

    SciTech Connect (OSTI)

    Donato, S.; Servidio, S.; Carbone, V. [Dipartimento di Fisica, Universita della Calabria, I-87036 Cosenza (Italy); Dmitruk, P. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Fisica de Buenos Aires, CONICET, Buenos Aires (Argentina); Shay, M. A.; Matthaeus, W. H. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Cassak, P. A. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

    2012-09-15

    The statistical study of magnetic reconnection events in two-dimensional turbulence has been performed by comparing numerical simulations of magnetohydrodynamics (MHD) and Hall magnetohydrodynamics (HMHD). The analysis reveals that the Hall term plays an important role in turbulence, in which magnetic islands simultaneously reconnect in a complex way. In particular, an increase of the Hall parameter, the ratio of ion skin depth to system size, broadens the distribution of reconnection rates relative to the MHD case. Moreover, in HMHD the local geometry of the reconnection region changes, manifesting bifurcated current sheets and quadrupolar magnetic field structures in analogy to laminar studies, leading locally to faster reconnection processes in this case of reconnection embedded in turbulence. This study supports the idea that the global rate of energy dissipation is controlled by the large scale turbulence, but suggests that the distribution of the reconnection rates within the turbulent system is sensitive to the microphysics at the reconnection sites.

  18. Admittance of multiterminal quantum Hall conductors at kilohertz frequencies

    SciTech Connect (OSTI)

    Hernndez, C.; Consejo, C.; Chaubet, C.; Degiovanni, P.

    2014-03-28

    We present an experimental study of the low frequency admittance of quantum Hall conductors in the [100?Hz, 1?MHz] frequency range. We show that the frequency dependence of the admittance of the sample strongly depends on the topology of the contacts connections. Our experimental results are well explained within the Christen and Bttiker approach for finite frequency transport in quantum Hall edge channels taking into account the influence of the coaxial cables capacitance. In the Hall bar geometry, we demonstrate that there exists a configuration in which the cable capacitance does not influence the admittance measurement of the sample. In this case, we measure the electrochemical capacitance of the sample and observe its dependence on the filling factor.

  19. On the question of hysteresis in Hall magnetohydrodynamic reconnection

    SciTech Connect (OSTI)

    Sullivan, Brian P.; Bhattacharjee, A.; Huang Yimin

    2010-11-15

    Controversy has been raised regarding the cause of hysteresis, or bistability, of solutions to the equations that govern the geometry of the reconnection region in Hall magnetohydrodynamic (MHD) systems. This brief communication presents a comparison of the frameworks within which this controversy has arisen and illustrates that the Hall MHD hysteresis originally discovered numerically by Cassak et al. [Phys. Rev. Lett. 95, 235002 (2005)] is a different phenomenon from that recently reported by Zocco et al. [Phys. Plasmas 16, 110703 (2009)] on the basis of analysis and simulations in electron MHD with finite electron inertia. We demonstrate that the analytic prediction of hysteresis in EMHD does not describe or explain the hysteresis originally reported in Hall MHD, which is shown to persist even in the absence of electron inertia.

  20. Study of the effects of guide field on Hall reconnection

    SciTech Connect (OSTI)

    Tharp, T. D.; Yamada, M.; Ji, H.; Lawrence, E.; Dorfman, S.; Myers, C.; Yoo, J.; Huang, Y.-M.; Bhattacharjee, A.

    2013-05-15

    The results from guide field studies on the Magnetic Reconnection Experiment (MRX) are compared with results from Hall magnetohydrodynamic (HMHD) reconnection simulation with guide field. The quadrupole field, a signature of two-fluid reconnection at zero guide field, is modified by the presence of a finite guide field in a manner consistent with HMHD simulation. The modified Hall current profile contains reduced electron flows in the reconnection plane, which quantitatively explains the observed reduction of the reconnection rate. The present results are consistent with the hypothesis that the local reconnection dynamics is dominated by Hall effects in the collisionless regime of the MRX plasmas. While very good agreement is seen between experiment and simulations, we note that an important global feature of the experiments, a compression of the guide field by the reconnecting plasma, is not represented in the simulations.

  1. Hall effect in a strong magnetic field: Direct comparisons of compressible magnetohydrodynamics and the reduced Hall magnetohydrodynamic equations

    SciTech Connect (OSTI)

    Martin, L. N.; Dmitruk, P.; Gomez, D. O.

    2010-11-15

    In this work we numerically test a model of Hall magnetohydrodynamics in the presence of a strong mean magnetic field: the reduced Hall magnetohydrodynamic model (RHMHD) derived by [Gomez et al., Phys. Plasmas 15, 102303 (2008)] with the addition of weak compressible effects. The main advantage of this model lies in the reduction of computational cost. Nevertheless, up until now the degree of agreement with the original Hall MHD system and the range of validity in a regime of turbulence were not established. In this work direct numerical simulations of three-dimensional Hall MHD turbulence in the presence of a strong mean magnetic field are compared with simulations of the weak compressible RHMHD model. The results show that the degree of agreement is very high (when the different assumptions of RHMHD, such as spectral anisotropy, are satisfied). Nevertheless, when the initial conditions are isotropic but the mean magnetic field is maintained strong, the results differ at the beginning but asymptotically reach a good agreement at relatively short times. We also found evidence that the compressibility still plays a role in the dynamics of these systems, and the weak compressible RHMHD model is able to capture these effects. In conclusion the weak compressible RHMHD model is a valid approximation of the Hall MHD turbulence in the relevant physical context.

  2. Quantum anomalous Hall effect in topological insulator memory

    SciTech Connect (OSTI)

    Jalil, Mansoor B. A.; Tan, S. G.; Siu, Z. B.

    2015-05-07

    We theoretically investigate the quantum anomalous Hall effect (QAHE) in a magnetically coupled three-dimensional-topological insulator (3D-TI) system. We apply the generalized spin-orbit coupling Hamiltonian to obtain the Hall conductivity σ{sup xy} of the system. The underlying topology of the QAHE phenomenon is then analyzed to show the quantization of σ{sup xy} and its relation to the Berry phase of the system. Finally, we analyze the feasibility of utilizing σ{sup xy} as a memory read-out in a 3D-TI based memory at finite temperatures, with comparison to known magnetically doped 3D-TIs.

  3. Nanoconstriction-based spin-Hall nano-oscillator

    SciTech Connect (OSTI)

    Demidov, V. E.; Urazhdin, S.; Zholud, A.; Sadovnikov, A. V.; Demokritov, S. O.

    2014-10-27

    We experimentally demonstrate magnetic nano-oscillators driven by pure spin current produced by the spin Hall effect in a bow tie-shaped nanoconstriction. These devices exhibit single-mode auto-oscillation and generate highly-coherent electronic microwave signals with a significant power and the spectral linewidth as low as 6.2 MHz at room temperature. The proposed simple and flexible device geometry is amenable to straightforward implementation of advanced spintronic structures such as chains of mutually coupled spin-Hall nano-oscillators.

  4. Inverse spin Hall effect in Pt/(Ga,Mn)As

    SciTech Connect (OSTI)

    Nakayama, H.; Chen, L.; Chang, H. W.; Ohno, H.; Matsukura, F.

    2015-06-01

    We investigate dc voltages under ferromagnetic resonance in a Pt/(Ga,Mn)As bilayer structure. A part of the observed dc voltage is shown to originate from the inverse spin Hall effect. The sign of the inverse spin Hall voltage is the same as that in Py/Pt bilayer structure, even though the stacking order of ferromagnetic and nonmagnetic layers is opposite to each other. The spin mixing conductance at the Pt/(Ga,Mn)As interface is determined to be of the order of 10{sup 19 }m{sup −2}, which is about ten times greater than that of (Ga,Mn)As/p-GaAs.

  5. Quantum anomalous Hall effect in single-layer and bilayer graphene...

    Office of Scientific and Technical Information (OSTI)

    Quantum anomalous Hall effect in single-layer and bilayer graphene Citation Details In-Document Search Title: Quantum anomalous Hall effect in single-layer and bilayer graphene ...

  6. 06.27.14 SRS Retirees Town Hall Meeting-Dave Hepner Page...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Meeting-Dave Hepner Page 1 SRSRA TOWN HALL MEETING New Ellenton Community Center JUNE 27, 2014 After reviewing the notes and discussing the Town Hall Meeting held on June 27, 2014,...

  7. VEE-0067- In the Matter of M.L. Halle Oil Service, Inc.

    Broader source: Energy.gov [DOE]

    On August 9, 1999 M.L. Halle Oil Service, Inc. (Halle) of Manchester, New Hampshire, filed an Application for Exception with the Office of Hearings and Appeals (OHA) of the Department of Energy ...

  8. Bernhard Mecking steps down as Hall B leader at Jefferson Lab | Jefferson

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lab Bernhard Mecking steps down as Hall B leader at Jefferson Lab Bernhard Mecking Jefferson Lab staff scientist Bernhard Mecking with the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B. Bernhard Mecking steps down as Hall B leader at Jefferson Lab April 2, 2003 On 1 February 2003, Bernhard Mecking stepped down as leader of Hall B to return to full-time research at the Department of Energy's Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, Virginia.

  9. Lodging

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lodging Lodging Los Alamos National Laboratory is situated on a mesatop on the eastern side of the Jemez Mountains, an impressive series of ancient volcanoes with extensive views of the Sangre de Cristo Mountains in the east, where sunsets turn the western slopes a vibrant red. We hope you enjoy your stay in the Land of Enchantment. There are several hotels in and around Los Alamos ready to give you a good night's rest. You also may bring camping gear and camp out at the "Dome." Note

  10. Lodging

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lodging Lodging Meeting Hotel - Hyatt Regency Bethesda NOTE: Rooms on June 9 are sold out at the Hyatt Regency. Please select one of the alternate hotels below. All are offering the government rate of $229 per night. A reserved room block has been made at the Hyatt Regency Bethesda. Use the following link to make reservations: https://resweb.passkey.com/go/HEEA. The cutoff data for room reservations is May 10, 2015. Alternate Hotels Ask for the government rate ($229 per night). Bethesa Court

  11. Recent Results of TMD Measurements from Jefferson Lab Hall A

    SciTech Connect (OSTI)

    Jiang, Xiaodong

    2013-10-01

    This slide-show presents results on transverse momentum distributions. The presentation covers: target single-spin asymmetry (SSA) (in parity conserving interactions); Results of JLab Hall A polarized {sup 3}He target TMD measurement; Semi-?inclusive deep-inelastic scattering channels (E06-010); Target single-spin asymmetry A{sub UT}, Collins and Sivers SSA on neutron; Double-spin asymmetry A{sub LT}, extract TMD g{sub 1T} on neutron; Inclusive channels SSA (E06-010, E05-015, E07-013) Target SSA: inclusive {sup 3}He(e,e) quasi-elastic scattering; Target SSA: inclusive {sup 3}He(e,e) deep inelastic-elastic scattering; New SIDIS experiments planned in Hall-A for JLab-12 GeV.

  12. Measurements of Plasma Potential Distribution in Segmented Electrode Hall Thruster

    SciTech Connect (OSTI)

    Y. Raitses; D. Staack; N.J. Fisch

    2001-10-16

    Use of a segmented electrode placed at the Hall thruster exit can substantially reduce the voltage potential drop in the fringing magnetic field outside the thruster channel. In this paper, we investigate the dependence of this effect on thruster operating conditions and segmented electrode configuration. A fast movable emissive probe is used to measure plasma potential in a 1 kW laboratory Hall thruster with semented electrodes made of a graphite material. Relatively small probe-induced perturbations of the thruster discharge in the vicinity of the thruster exit allow a reasonable comparison of the measured results for different thruster configurations. It is shown that the plasma potential distribution is almost not sensitive to changes of the electrode potential, but depends on the magnetic field distribution and the electrode placement.

  13. Contactless measurement of alternating current conductance in quantum Hall structures

    SciTech Connect (OSTI)

    Drichko, I. L.; Diakonov, A. M.; Malysh, V. A.; Smirnov, I. Yu.; Ilyinskaya, N. D.; Usikova, A. A.; Galperin, Y. M.; Kummer, M.; Känel, H. von

    2014-10-21

    We report a procedure to determine the frequency-dependent conductance of quantum Hall structures in a broad frequency domain. The procedure is based on the combination of two known probeless methods—acoustic spectroscopy and microwave spectroscopy. By using the acoustic spectroscopy, we study the low-frequency attenuation and phase shift of a surface acoustic wave in a piezoelectric crystal in the vicinity of the electron (hole) layer. The electronic contribution is resolved using its dependence on a transverse magnetic field. At high frequencies, we study the attenuation of an electromagnetic wave in a coplanar waveguide. To quantitatively calibrate these data, we use the fact that in the quantum-Hall-effect regime the conductance at the maxima of its magnetic field dependence is determined by extended states. Therefore, it should be frequency independent in a broad frequency domain. The procedure is verified by studies of a well-characterized p-SiGe/Ge/SiGe heterostructure.

  14. Precise quantization of anomalous Hall effect near zero magnetic field

    SciTech Connect (OSTI)

    Bestwick, A. J.; Fox, E. J.; Kou, Xufeng; Pan, Lei; Wang, Kang L.; Goldhaber-Gordon, D.

    2015-05-04

    In this study, we report a nearly ideal quantum anomalous Hall effect in a three-dimensional topological insulator thin film with ferromagnetic doping. Near zero applied magnetic field we measure exact quantization in the Hall resistance to within a part per 10,000 and a longitudinal resistivity under 1 Ω per square, with chiral edge transport explicitly confirmed by nonlocal measurements. Deviations from this behavior are found to be caused by thermally activated carriers, as indicated by an Arrhenius law temperature dependence. Using the deviations as a thermometer, we demonstrate an unexpected magnetocaloric effect and use it to reach near-perfect quantization by cooling the sample below the dilution refrigerator base temperature in a process approximating adiabatic demagnetization refrigeration.

  15. Fractionally charged skyrmions in fractional quantum Hall effect

    SciTech Connect (OSTI)

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; Pinczuk, A.; Jain, J. K.

    2015-11-26

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.

  16. Effects of Enhanced Eathode Electron Emission on Hall Thruster Operation

    SciTech Connect (OSTI)

    Y. Raitses, A. Smirnov and N. J. Fisch

    2009-04-24

    Interesting discharge phenomena are observed that have to do with the interaction between the magnetized Hall thruster plasma and the neutralizing cathode. The steadystate parameters of a highly ionized thruster discharge are strongly influenced by the electron supply from the cathode. The enhancement of the cathode electron emission above its self-sustained level affects the discharge current and leads to a dramatic reduction of the plasma divergence and a suppression of large amplitude, low frequency discharge current oscillations usually related to an ionization instability. These effects correlate strongly with the reduction of the voltage drop in the region with the fringing magnetic field between the thruster channel and the cathode. The measured changes of the plasma properties suggest that the electron emission affects the electron cross-field transport in the thruster discharge. These trends are generalized for Hall thrusters of various configurations.

  17. Intermittency in Hall-magnetohydrodynamics with a strong guide field

    SciTech Connect (OSTI)

    Rodriguez Imazio, P.; Martin, L. N.; Dmitruk, P.; Mininni, P. D.; National Center for Atmospheric Research, P.O. Box 3000, Boulder, Colorado 80307

    2013-05-15

    We present a detailed study of intermittency in the velocity and magnetic field fluctuations of compressible Hall-magnetohydrodynamic turbulence with an external guide field. To solve the equations numerically, a reduced model valid when a strong guide field is present is used. Different values for the ion skin depth are considered in the simulations. The resulting data are analyzed computing field increments in several directions perpendicular to the guide field, and building structure functions and probability density functions. In the magnetohydrodynamic limit, we recover the usual results with the magnetic field being more intermittent than the velocity field. In the presence of the Hall effect, field fluctuations at scales smaller than the ion skin depth show a substantial decrease in the level of intermittency, with close to monofractal scaling.

  18. NE-24 Gilman Hall, University of California, Certification Documentation

    Office of Legacy Management (LM)

    Gilman Hall, University of California, Certification Documentation Berkeley, California, Conditional Verlette Gatlin, MA-232 I am attaching for entry into the Public Document Room, two copies of the subject documentation. These documents are the backup data for the conditional certification that the site is radiologically acceptable for restricted use as noted in the certification statement published in the Federal Register. Inasmuch as the conditional certification is made public through the

  19. Gradient instabilities of electromagnetic waves in Hall thruster plasma

    SciTech Connect (OSTI)

    Tomilin, Dmitry

    2013-04-15

    This paper presents a linear analysis of gradient plasma instabilities in Hall thrusters. The study obtains and analyzes the dispersion equation of high-frequency electromagnetic waves based on the two-fluid model of a cold plasma. The regions of parameters corresponding to unstable high frequency modes are determined and the dependence of the increments and intrinsic frequencies on plasma parameters is obtained. The obtained results agree with those of previously published studies.

  20. Jackie Chen inducted into Alameda County Women's Hall of Fame

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    inducted into Alameda County Women's Hall of Fame - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste

  1. Quantum Hall effect in graphene decorated with disordered multilayer patches

    SciTech Connect (OSTI)

    Nam, Youngwoo; Sun, Jie Lindvall, Niclas; Kireev, Dmitry; Yurgens, August; Jae Yang, Seung; Rae Park, Chong; Woo Park, Yung

    2013-12-02

    Quantum Hall effect (QHE) is observed in graphene grown by chemical vapour deposition using platinum catalyst. The QHE is even seen in samples which are irregularly decorated with disordered multilayer graphene patches and have very low mobility (<500 cm{sup 2}V{sup −1}s{sup −1}). The effect does not seem to depend on electronic mobility and uniformity of the resulting material, which indicates the robustness of QHE in graphene.

  2. Transition in Electron Transport in a Cylindrical Hall Thruster

    SciTech Connect (OSTI)

    J.B. Parker, Y. Raitses, and N.J. Fisch

    2010-06-02

    Through the use of high-speed camera and Langmuir probe measurements in a cylindrical Hall thruster, we report the discovery of a rotating spoke of increased plasma density and light emission which correlates with increased electron transport across the magnetic field. As cathode electron emission is increased, a sharp transition occurs where the spoke disappears and electron transport decreases. This suggests that a significant fraction of the electron current might be directed through the spoke.

  3. Metal-to-insulator switching in quantum anomalous Hall states

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kou, Xufeng; Pan, Lei; Wang, Jing; Fan, Yabin; Choi, Eun Sang; Lee, Wei -Li; Nie, Tianxiao; Murata, Koichi; Shao, Qiming; Zhang, Shou -Cheng; et al

    2015-10-07

    After decades of searching for the dissipationless transport in the absence of any external magnetic field, quantum anomalous Hall effect (QAHE) was recently achieved in magnetic topological insulator films. However, the universal phase diagram of QAHE and its relation with quantum Hall effect (QHE) remain to be investigated. Here, we report the experimental observation of the giant longitudinal resistance peak and zero Hall conductance plateau at the coercive field in the six quintuple-layer (Cr0.12Bi0.26Sb0.62)2Te3 film, and demonstrate the metal-to-insulator switching between two opposite QAHE plateau states up to 0.3 K. Moreover, the universal QAHE phase diagram is confirmed through themore » angle-dependent measurements. Our results address that the quantum phase transitions in both QAHE and QHE regimes are in the same universality class, yet the microscopic details are different. Additionally, the realization of the QAHE insulating state unveils new ways to explore quantum phase-related physics and applications.« less

  4. D0 Collision Hall Outdoor Fresh Air Makeup

    SciTech Connect (OSTI)

    Markley, D.; /Fermilab

    1992-03-27

    This note will briefly describe the collision hall ventilation system and how D0 will monitor outside air makeup and what actions occur in the event of system failures. The Dzero collision hall has two different fresh air makeup conditions it must meet. They are: (1) Tunnel Barriers removed-Fresh air makeup = 4500 CFM; and (2) Tunnel Barriers in place-Fresh air makeup = 2800 CFM. This note demonstrates how the fresh air minimums are met and guaranteed. The air flow paths and ducts at D0 for both AHU1 and EF-7 are fixed. The blower throughputs are not variable. The software stops on AHU1's dampers will be set for a minimum of 2800 cfm or 4500 cfm of outdoor air continuously added to the HVAC flow stream depending on the tunnel barrier state. AHU1 and EF-7 both have monitoring that can determine reliably as to whether the respective blower is on or off. Since the outside air makeup is fixed as long as the blowers are running, and the software AHU1 damper limits are set, we can rely on the blower status indicators to determine as to whether the collision hall is receiving the proper amount of outside makeup air.

  5. Metal-to-insulator switching in quantum anomalous Hall states

    SciTech Connect (OSTI)

    Kou, Xufeng; Pan, Lei; Wang, Jing; Fan, Yabin; Choi, Eun Sang; Lee, Wei -Li; Nie, Tianxiao; Murata, Koichi; Shao, Qiming; Zhang, Shou -Cheng; Wang, Kang L.

    2015-10-07

    After decades of searching for the dissipationless transport in the absence of any external magnetic field, quantum anomalous Hall effect (QAHE) was recently achieved in magnetic topological insulator films. However, the universal phase diagram of QAHE and its relation with quantum Hall effect (QHE) remain to be investigated. Here, we report the experimental observation of the giant longitudinal resistance peak and zero Hall conductance plateau at the coercive field in the six quintuple-layer (Cr0.12Bi0.26Sb0.62)2Te3 film, and demonstrate the metal-to-insulator switching between two opposite QAHE plateau states up to 0.3 K. Moreover, the universal QAHE phase diagram is confirmed through the angle-dependent measurements. Our results address that the quantum phase transitions in both QAHE and QHE regimes are in the same universality class, yet the microscopic details are different. Additionally, the realization of the QAHE insulating state unveils new ways to explore quantum phase-related physics and applications.

  6. Magnetic shielding of a laboratory Hall thruster. II. Experiments

    SciTech Connect (OSTI)

    Hofer, Richard R. Goebel, Dan M.; Mikellides, Ioannis G.; Katz, Ira

    2014-01-28

    The physics of magnetic shielding in Hall thrusters were validated through laboratory experiments demonstrating essentially erosionless, high-performance operation. The magnetic field near the walls of a laboratory Hall thruster was modified to effectively eliminate wall erosion while maintaining the magnetic field topology away from the walls necessary to retain efficient operation. Plasma measurements at the walls validate our understanding of magnetic shielding as derived from the theory. The plasma potential was maintained very near the anode potential, the electron temperature was reduced by a factor of two to three, and the ion current density was reduced by at least a factor of two. Measurements of the carbon backsputter rate, wall geometry, and direct measurement of plasma properties at the wall indicate that the wall erosion rate was reduced by a factor of 1000 relative to the unshielded thruster. These changes effectively eliminate wall erosion as a life limitation in Hall thrusters, enabling a new class of deep-space missions that could not previously be attempted.

  7. Physics and modeling of an end-Hall (gridless) ion source

    SciTech Connect (OSTI)

    Oudini, N.; Hagelaar, G. J. M.; Boeuf, J.-P.; Garrrigues, L.

    2011-04-01

    In an end-Hall source, an ion beam is extracted from a magnetized plasma and accelerated by the plasma electric field without grids. The principle of end-Hall sources is similar to that of Hall effect thrusters (or closed-drift thrusters), but their design is optimized for processing applications (ion beam assisted deposition or substrate cleaning) rather than propulsion. The beam divergence is larger in end-Hall ion sources, and these sources can operate at low ion energies. Although end-Hall sources are commonly used in the surface processing industry, no detailed modeling of these sources is available, and their operation is quite empirical. In this paper, a self-consistent, two-dimensional, quasineutral model of an end-Hall ion source is developed and used in order to improve the understanding of the basic physics of these plasma sources and to quantify the parameters controlling the properties of the extracted ion beam.

  8. AGU SubTER Town Hall Presentation 2015 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AGU SubTER Town Hall Presentation 2015 AGU SubTER Town Hall Presentation 2015 AGU SubTER Townhall 2015.pdf (4.49 MB) More Documents & Publications SubTER Presentation at Town Hall - American Geophysical Union Poster on Subsurface Technology & Engineering Research, Development, and Demonstration Crosscut (SubTER) Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda

  9. June 24, 2015 in 100E Hildebrand Hall | Center for Gas SeparationsRele...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    4, 2015 in 100E Hildebrand Hall Previous Next List Stephen Meckler (Lawrence Berkeley National Laboratory) Layered Zif-Polymer Composites Accessed through Metal Oxide Precursors...

  10. PREPRINT QUASIPARTICLE AGGREGATION I N THE FRACTIONAL QUANTUM HALL EFFECT

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    91618 PREPRINT QUASIPARTICLE AGGREGATION I N THE FRACTIONAL QUANTUM HALL EFFECT R. B. Laughlin This paper was prepared for submittal to the Proceedings of the 17th International Conference on the Physics of Semi conductors San Francisco, California August 6-10, 1984 October 10, 1984 This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the un- derstanding that it will not be cited or

  11. Topological Hall conductivity of vortex and skyrmion spin textures

    SciTech Connect (OSTI)

    Jalil, M. B. A. Ghee Tan, Seng; Eason, Kwaku; Kong, Jian Feng

    2014-05-07

    We analyze the topological Hall conductivity experienced by conduction electrons whose spins are strongly coupled to axially symmetric spin textures, such as magnetic vortex and skyrmion of types I and II, theoretically by gauge theory, and numerically via micromagnetic simulations. The numerical results are in agreement with the theoretical predictions. Divergence between the two is seen when the vortex/skyrmion core radius is comparable or larger than the element size, and when the skyrmion configuration breaks down at high Dzyaloshinskii-Moriya interaction strength.

  12. Plasma lens and plume divergence in the Hall thruster

    SciTech Connect (OSTI)

    Fruchtman, A.; Cohen-Zur, A.

    2006-09-11

    The effect of magnetic field curvature on the plume divergence in the Hall thruster is analyzed. The two-dimensional plasma flow and electric field are determined self-consistently within the paraxial approximation in this plasma lens, a nearly axial electric field perpendicular to the curved magnetic field lines. The ion radial velocity along the thruster is described analytically. The authors suggest positioning the ionization layer near the zero of the magnetic field in a reversing-direction field configuration for a minimal beam divergence. They also show that an additional emitting electrode can reduce plume divergence.

  13. Vortex equations governing the fractional quantum Hall effect

    SciTech Connect (OSTI)

    Medina, Luciano

    2015-09-15

    An existence theory is established for a coupled non-linear elliptic system, known as “vortex equations,” describing the fractional quantum Hall effect in 2-dimensional double-layered electron systems. Via variational methods, we prove the existence and uniqueness of multiple vortices over a doubly periodic domain and the full plane. In the doubly periodic situation, explicit sufficient and necessary conditions are obtained that relate the size of the domain and the vortex numbers. For the full plane case, existence is established for all finite-energy solutions and exponential decay estimates are proved. Quantization phenomena of the magnetic flux are found in both cases.

  14. Materials for Giant Spin Hall Device | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Materials for Giant Spin Hall Device September 7, 2016 11:00AM to 12:00PM Presenter Avyaya Jayanthinarasimham, State University of New York-Albany Location Building 223, Room S105 Type Seminar Series MSD Seminar Abstract: Spin-orbit coupling in metastable β-W generates spin-orbit torques (SOTs) strong enough to flip the magnetic moment of an adjacent magnetic layer. In a magnetic tunnel junction (MTJ) stack, these torques can be used to switch between high and low resistive states. Deposition

  15. ,The Honorable Thomas Henino City Hall Plaza I

    Office of Legacy Management (LM)

    Department of Energy Washington,. DC 20585 MAR 29 1995 ,The Honorable Thomas Henino City Hall Plaza I Boston, Massachusetts 02201 '. ! Dear Mayor Menino: Even though additional involvement by DOE is,not necessary at this site, we are prepared to respond to any concerns you may have. -' : __ if you have any questions,' please feel free to call me eat 301-427li721 or Dr. W. Alexander Willlams (301-427-1719)~of my staff. ' gyp , ,~.&.Qz J ~ J / d .!~a : T- " ames W. Wagoner I -. Secretary

  16. Titanium diboride ceramic fiber composites for Hall-Heroult cells

    DOE Patents [OSTI]

    Besmann, T.M.; Lowden, R.A.

    1990-05-29

    An improved cathode structure is described for Hall-Heroult cells for the electrolytic production of aluminum metal. This cathode structure is a preform fiber base material that is infiltrated with electrically conductive titanium diboride using chemical vapor infiltration techniques. The structure exhibits good fracture toughness, and is sufficiently resistant to attack by molten aluminum. Typically, the base can be made from a mat of high purity silicon carbide fibers. Other ceramic or carbon fibers that do not degrade at temperatures below about 1000 C can be used.

  17. Titanium diboride ceramic fiber composites for Hall-Heroult cells

    DOE Patents [OSTI]

    Besmann, Theodore M.; Lowden, Richard A.

    1990-01-01

    An improved cathode structure for Hall-Heroult cells for the electrolytic production of aluminum metal. This cathode structure is a preform fiber base material that is infiltrated with electrically conductive titanium diboride using chemical vapor infiltration techniques. The structure exhibits good fracture toughness, and is sufficiently resistant to attack by molten aluminum. Typically, the base can be made from a mat of high purity silicon carbide fibers. Other ceramic or carbon fibers that do not degrade at temperatures below about 1000 deg. C can be used.

  18. Fractionally charged skyrmions in fractional quantum Hall effect

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; Pinczuk, A.; Jain, J. K.

    2015-11-26

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeemanmore » energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.« less

  19. Hall effect in quantum critical charge-cluster glass

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bozovic, Ivan; Wu, Jie; Bollinger, Anthony T.; Sun, Yujie

    2016-04-04

    Upon doping, cuprates undergo a quantum phase transition from an insulator to a d-wave superconductor. The nature of this transition and of the insulating state is vividly debated. Here, we study the Hall effect in La2-xSrxCuO4 (LSCO) samples doped near the quantum critical point at x ≈ 0.06. Dramatic fluctuations in the Hall resistance appear below TCG ≈ 1.5 K and increase as the sample is cooled down further, signaling quantum critical behavior. We explore the doping dependence of this effect in detail, by studying a combinatorial LSCO library in which the Sr content is varied in extremely fine steps,more » Δx ≈ 0.00008. Furthermore, we observe that quantum charge fluctuations wash out when superconductivity emerges but can be restored when the latter is suppressed by applying a magnetic field, showing that the two instabilities compete for the ground state.« less

  20. Hall magnetohydrodynamic reconnection in the plasmoid unstable regime

    SciTech Connect (OSTI)

    Baalrud, S. D.; Bhattacharjee, A.; Huang, Y.-M.; Germaschewski, K.

    2011-09-15

    A set of reduced Hall magnetohydrodynamic (MHD) equations are used to evaluate the stability of large aspect ratio current sheets to the formation of plasmoids (secondary islands). Reconnection is driven by resistivity in this analysis, which occurs at the resistive skin depth d{sub {eta}}{identical_to}S{sub L}{sup -1/2}{radical}(L{nu}{sub A}/{gamma}), where S{sub L} is the Lundquist number, L, the length of the current sheet, {nu}{sub A,} the Alfven speed, and {gamma}, the growth rate. Modifications to a recent resistive MHD analysis [N. F. Loureiro et al., Phys. Plasmas 14, 100703 (2007)] arise when collisions are sufficiently weak that d{sub {eta}} is shorter than the ion skin depth d{sub i}{identical_to}c/{omega}{sub pi}. Secondary islands grow faster in this Hall MHD regime: the maximum growth rate scales as (d{sub i}/L){sup 6/13}S{sub L}{sup 7/13}{nu}{sub A}/L and the number of plasmoids as (d{sub i}/L){sup 1/13}S{sub L}{sup 11/26}, compared to S{sub L}{sup 1/4}{nu}{sub A}/L and S{sup 3/8}, respectively, in resistive MHD.

  1. Refrigeration Recovery for Experiment Hall High Target Loads

    SciTech Connect (OSTI)

    Peter Knudsen, Venkatarao Ganni, Errol Yuksek, Jonathan Creel

    2010-04-01

    The Qweak experiment at Jefferson Lab (JLab) is a 3000 W hydrogen target scheduled for the summer of 2010 and running for two years until the planned shut-down for 12GeV. The End Station Refrigerator (ESR) supports the three experiment halls, two of which may normally have a hydrogen target. The refrigerator for the ESR is a CTI/Helix 1500 W 4.5-K refrigerator nominally capable of supporting a 1250 W target load at 12 bar and 15-K (plus 1100 W of 4.5-K refrigeration). As such, this refrigerator is not capable of supporting the Qweak experiment target load in its present condition. Additionally, since the installation of an ambient air vaporizer for a single use, two week run duration of a high target load in the summer of 2003 there has been a consistent usage of the Central Helium Liquefier’s (CHL’s) 3 bar 4.5-K helium, supplied via an existing transfer-line to the ESR, for other high target loads. By the fall of 2004, it was apparent that this continued use of CHL’s supercritical helium was routinely being sought by the hall experimenters. As such, a method of refrigeration recovery was proposed to reduce the support required of CHL for these high target loads, including the anticipated Qweak experiment, while utilizing the recovered CHL refrigeration from the target to increase ESR’s 12 bar 15-K capacity.

  2. Magnetic shielding of walls from the unmagnetized ion beam in a Hall thruster

    SciTech Connect (OSTI)

    Mikellides, Ioannis G.; Katz, Ira; Hofer, Richard R.; Goebel, Dan M.

    2013-01-14

    We demonstrate by numerical simulations and experiments that the unmagnetized ion beam formed in a Hall thruster can be controlled by an applied magnetic field in a manner that reduces by 2-3 orders of magnitude deleterious ion bombardment of the containing walls. The suppression of wall erosion in Hall thrusters to such low levels has remained elusive for decades.

  3. Quantitative analytical model for magnetic reconnection in hall magnetohydrodynamics

    SciTech Connect (OSTI)

    Simakov, Andrei N

    2008-01-01

    Magnetic reconnection is of fundamental importance for laboratory and naturally occurring plasmas. Reconnection usually develops on time scales which are much shorter than those associated with classical collisional dissipation processes, and which are not fully understood. While such dissipation-independent (or 'fast') reconnection rates have been observed in particle and Hall magnetohydrodynamics (MHD) simulations and predicted analytically in electron MHD, a quantitative analytical theory of fast reconnection valid for arbitrary ion inertial lengths d{sub i} has been lacking. Here we propose such a theory without a guide field. The theory describes two-dimensional magnetic field diffusion regions, provides expressions for the reconnection rates, and derives a formal criterion for fast reconnection in terms of dissipation parameters and di. It also demonstrates that both open X-point and elongated diffusion regions allow dissipation-independent reconnection and reveals a possibility of strong dependence of the reconnection rates on d{sub i}.

  4. A low-cost multiple Hall probe current transducer

    SciTech Connect (OSTI)

    Scoville, J.T.; Petersen, P.I. )

    1991-03-01

    An inexpensive but highly stable and accurate transducer has been developed for the measurement of large currents associated with the operation of the DIII-D tokamak at General Atomics. The inherent problems with integrator circuits required by Rogowski loops and the excessive cost of secondary compensation current'' devices have led to this development. The transducer requires several inexpensive Hall effect devices and a simple, stable, and linear interface circuit. Analysis of the initial performance characteristics is very encouraging and has led to several useful applications of the transducer to date, with plans for the installation of additional devices in the future. The low cost and reasonable accuracy of the transducer make it an attractive alternative to commercially available devices.

  5. Perturbation analysis of ionization oscillations in Hall effect thrusters

    SciTech Connect (OSTI)

    Hara, Kentaro Sekerak, Michael J.; Boyd, Iain D.; Gallimore, Alec D.

    2014-12-15

    A perturbation analysis of ionization oscillations, which cause low frequency oscillations of the discharge plasma, in Hall effect thrusters is presented including the electron energy equation in addition to heavy-species transport. Excitation and stabilization of such oscillations, often called the breathing mode, are discussed in terms of the growth rate obtained from the linear perturbation equations of the discharge plasma. The instability induced from the ionization occurs only when the perturbation in the electron energy is included while the neutral atom flow contributes to the damping of the oscillation. Effects of the electron energy loss mechanisms such as wall heat loss, inelastic collisions, and convective heat flux are discussed. It is shown that the ionization oscillations can be damped when the electron transport is reduced and the electron temperature increases so that the energy loss to the wall stabilizes the ionization instability.

  6. Hall MHD Stability and Turbulence in Magnetically Accelerated Plasmas

    SciTech Connect (OSTI)

    H. R. Strauss

    2012-11-27

    The object of the research was to develop theory and carry out simulations of the Z pinch and plasma opening switch (POS), and compare with experimental results. In the case of the Z pinch, there was experimental evidence of ion kinetic energy greatly in excess of the ion thermal energy. It was thought that this was perhaps due to fine scale turbulence. The simulations showed that the ion energy was predominantly laminar, not turbulent. Preliminary studies of a new Z pinch experiment with an axial magnetic field were carried out. The axial magnetic is relevant to magneto - inertial fusion. These studies indicate the axial magnetic field makes the Z pinch more turbulent. Results were also obtained on Hall magnetohydrodynamic instability of the POS.

  7. The Hall D solenoid helium refrigeration system at JLab

    SciTech Connect (OSTI)

    Laverdure, Nathaniel A.; Creel, Jonathan D.; Dixon, Kelly d.; Ganni, Venkatarao; Martin, Floyd D.; Norton, Robert O.; Radovic, Sasa

    2014-01-01

    Hall D, the new Jefferson Lab experimental facility built for the 12GeV upgrade, features a LASS 1.85 m bore solenoid magnet supported by a 4.5 K helium refrigerator system. This system consists of a CTI 2800 4.5 K refrigerator cold box, three 150 hp screw compressors, helium gas management and storage, and liquid helium and nitrogen storage for stand-alone operation. The magnet interfaces with the cryo refrigeration system through an LN2-shielded distribution box and transfer line system, both designed and fabricated by JLab. The distribution box uses a thermo siphon design to respectively cool four magnet coils and shields with liquid helium and nitrogen. We describe the salient design features of the cryo system and discuss our recent commissioning experience.

  8. Medicine Lodge Intermediate Facility

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Medicine Lodge

  9. Quantum Anomalous Hall Effect in Hg_1-yMn_yTe Quantum Wells

    SciTech Connect (OSTI)

    Liu, Chao-Xing; Qi, Xiao-Liang; Dai, Xi; Fang, Zhong; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-03-19

    The quantum Hall effect is usually observed when the two-dimensional electron gas is subjected to an external magnetic field, so that their quantum states form Landau levels. In this work we predict that a new phenomenon, the quantum anomalous Hall effect, can be realized in Hg{sub 1-y}Mn{sub y}Te quantum wells, without the external magnetic field and the associated Landau levels. This effect arises purely from the spin polarization of the Mn atoms, and the quantized Hall conductance is predicted for a range of quantum well thickness and the concentration of the Mn atoms. This effect enables dissipationless charge current in spintronics devices.

  10. Formation of quantum spin Hall state on Si surface and energy gap scaling

    Office of Scientific and Technical Information (OSTI)

    with strength of spin orbit coupling (Journal Article) | SciTech Connect Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling Citation Details In-Document Search Title: Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling For potential applications in spintronics and quantum computing, it is desirable to place a quantum spin Hall insulator [i.e., a 2D topological insulator

  11. Ultrahigh sensitivity of anomalous Hall effect sensor based on Cr-doped

    Office of Scientific and Technical Information (OSTI)

    Bi2Te3 topological insulator thin films (Journal Article) | SciTech Connect Ultrahigh sensitivity of anomalous Hall effect sensor based on Cr-doped Bi2Te3 topological insulator thin films Citation Details In-Document Search This content will become publicly available on July 1, 2017 Title: Ultrahigh sensitivity of anomalous Hall effect sensor based on Cr-doped Bi2Te3 topological insulator thin films Anomalous Hall effect (AHE) was recently discovered in magnetic element-doped topological

  12. President Obama Talks Clean Energy At Facebook Town Hall | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy At Facebook Town Hall President Obama Talks Clean Energy At Facebook Town Hall April 25, 2011 - 10:24am Addthis Ginny Simmons Ginny Simmons Former Managing Editor for Energy.gov, Office of Public Affairs What does this mean for me? We are investing in new technologies that will help us reduce our dependence on fossil fuels. By investing in STEM education, we are investing in our future. President Obama hosted a town hall at Facebook's headquarters last Wednesday to discuss the

  13. TBA-0042 - In the Matter of Curtis Hall | Department of Energy

    Office of Environmental Management (EM)

    42 - In the Matter of Curtis Hall TBA-0042 - In the Matter of Curtis Hall This Decision considers two Appeals of an Initial Agency Decision (IAD) issued on March 15, 2007, by a Hearing Officer in the Department of Energy's (DOE) Office of Hearings and Appeals (OHA). The IAD addressed the merits of a whistleblower complaint filed by Curtis Hall against his former employer, Bechtel National, Inc. (BNI), under the Department of Energy's Contractor Employee Protection Program, 10 C.F.R. Part 708.

  14. All electrical manipulation of magnetization dynamics in a ferromagnet by antiferromagnets with anisotropic spin Hall effects.

    SciTech Connect (OSTI)

    Zhang, Wei; Jungfleisch, Matthias B.; Freimuth, Frank; Jiang, Wanjun; Sklenar, Joseph; Pearson, John E.; Ketterson, John B.; Mokrousov, Yuri; Hoffmann, Axel

    2015-10-06

    We investigate spin-orbit torques of metallic CuAu-I-type antiferromagnets using spin-torque ferromagnetic resonance tuned by a dc-bias current. The observed spin torques predominantly arise from diffusive transport of spin current generated by the spin Hall effect. We find a growth-orientation dependence of the spin torques by studying epitaxial samples, which may be correlated to the anisotropy of the spin Hall effect. The observed anisotropy is consistent with first-principles calculations on the intrinsic spin Hall effect. Our work suggests large tunable spin-orbit effects in magnetically-ordered materials.

  15. Formation of quantum spin Hall state on Si surface and energy...

    Office of Scientific and Technical Information (OSTI)

    Si surface and energy gap scaling with strength of spin orbit coupling Title: Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit ...

  16. LEDS the focus of Monday's 10 a.m. Town Hall Meeting | OpenEI...

    Open Energy Info (EERE)

    LEDS the focus of Monday's 10 a.m. Town Hall Meeting Home > Blogs > Graham7781's blog Graham7781's picture Submitted by Graham7781(2017) Super contributor 16 November, 2012 - 11:23...

  17. Electron Cross-field Transport in a Low Power Cylindrical Hall Thruster

    SciTech Connect (OSTI)

    A. Smirnov; Y. Raitses; N.J. Fisch

    2004-06-24

    Conventional annular Hall thrusters become inefficient when scaled to low power. Cylindrical Hall thrusters, which have lower surface-to-volume ratio, are therefore more promising for scaling down. They presently exhibit performance comparable with conventional annular Hall thrusters. Electron cross-field transport in a 2.6 cm miniaturized cylindrical Hall thruster (100 W power level) has been studied through the analysis of experimental data and Monte Carlo simulations of electron dynamics in the thruster channel. The numerical model takes into account elastic and inelastic electron collisions with atoms, electron-wall collisions, including secondary electron emission, and Bohm diffusion. We show that in order to explain the observed discharge current, the electron anomalous collision frequency {nu}{sub B} has to be on the order of the Bohm value, {nu}{sub B} {approx} {omega}{sub c}/16. The contribution of electron-wall collisions to cross-field transport is found to be insignificant.

  18. Town Hall Meeting October 1st, 2012 | OpenEI Community

    Open Energy Info (EERE)

    Town Hall Meeting October 1st, 2012 Home > Blogs > Graham7781's blog Graham7781's picture Submitted by Graham7781(2017) Super contributor 19 September, 2012 - 13:40 OpenEI Town...

  19. The Honoradle':Rudolf Juiliani City'Hall New York, New York I0007

    Office of Legacy Management (LM)

    Wasthgton, DC 20585 ' ,,' . .' . . s ,' FEi,l 6 jg& ,. . . ' I s. i ,-' .' ,, -. ,. The Honoradle':Rudolf Juiliani City'Hall New York, New York I0007 i ', 1" Dear ...

  20. Beam Position Reconstruction for the g2p Experiment in Hall A...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Beam Position Reconstruction for the g2p Experiment in Hall A at Jefferson Lab Citation Details In-Document Search Title: Beam Position Reconstruction for the g2p...

  1. Anomalous Hall effect in magnetic disordered alloys: Effects of spin orbital coupling

    SciTech Connect (OSTI)

    Ma, L.; Gao, W. B.; Zhou, S. M.; Shi, Z.; He, P.; Miao, J.; Jiang, Y.

    2013-12-28

    For disordered ternary Fe{sub 0.5}(Pd{sub 1−x}Pt{sub x}){sub 0.5} alloy films, the anomalous Hall effect obeys the conventional scaling law ρ{sub AH}=aρ{sub xx}+bρ{sub xx}{sup 2} with the longitudinal resistivity ρ{sub xx} and anomalous Hall resistivity ρ{sub AH}. Contributed by the intrinsic term and the extrinsic side-jump one, the scattering-independent anomalous Hall conductivity b increases with increasing Pt/Pd concentration. In contrast, the skew scattering parameter a is mainly influenced by the residual resistivity. The present results will facilitate the theoretical studies of the anomalous Hall effect in magnetic disordered alloys.

  2. Metallization and Hall-effect of Mg{sub 2}Ge under high pressure

    SciTech Connect (OSTI)

    Li, Yuqiang; Gao, Yang; Han, Yonghao Liu, Cailong; Peng, Gang; Ke, Feng; Gao, Chunxiao; Wang, Qinglin; Ma, Yanzhang

    2015-10-05

    The electrical transport properties of Mg{sub 2}Ge under high pressure were studied with the in situ temperature-dependent resistivity and Hall-effect measurements. The theoretically predicted metallization of Mg{sub 2}Ge was definitely found around 7.4 GPa by the temperature-dependent resistivity measurement. Other two pressure-induced structural phase transitions were also reflected by the measurements. Hall-effect measurement showed that the dominant charge carrier in the metallic Mg{sub 2}Ge was hole, indicating the “bad metal” nature of Mg{sub 2}Ge. The Hall mobility and charge carrier concentration results pointed out that the electrical transport behavior in the antifluorite phase was controlled by the increase quantity of drifting electrons under high pressure, but in both anticotunnite and Ni{sub 2}In-type phases it was governed by the Hall mobility.

  3. Quantification of the spin-Hall anti-damping torque with a resonance spectrometer

    SciTech Connect (OSTI)

    Emori, Satoru Nan, Tianxiang; Oxholm, Trevor M.; Boone, Carl T.; Sun, Nian X.; Jones, John G.; Howe, Brandon M.; Brown, Gail J.; Budil, David E.

    2015-01-12

    We present a simple technique using a cavity-based resonance spectrometer to quantify the anti-damping torque due to the spin Hall effect. Modification of ferromagnetic resonance is observed as a function of small DC current in sub-mm-wide strips of bilayers, consisting of magnetically soft FeGaB and strong spin-Hall metal Ta. From the detected current-induced linewidth change, we obtain an effective spin Hall angle of 0.08–0.09 independent of the magnetic layer thickness. Our results demonstrate that a sensitive resonance spectrometer can be a general tool to investigate spin Hall effects in various material systems, even those with vanishingly low conductivity and magnetoresistance.

  4. After 105 Years, Historic City Hall in West Des Moines, Iowa...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... credit: Vicky Saylor EECBG Success Story: After 105 Years, Historic City Hall in West Des Moines, Iowa Goes Green Using money from the Energy Efficiency Block Grant Program, St. ...

  5. Micromagnetic study of auto-oscillation modes in spin-Hall nano-oscillators

    SciTech Connect (OSTI)

    Ulrichs, H. Demidov, V. E.; Demokritov, S. O.

    2014-01-27

    We present a numerical study of magnetization dynamics in a recently introduced spin torque nano-oscillator, whose operational principle relies on the spin-Hall effect—spin-Hall nano-oscillators. Our numerical results show good agreement with the experimentally observed behaviors and provide detailed information about the features of the primary auto-oscillation mode observed in the experiments. They also clarify the physical nature of the secondary auto-oscillation mode, which was experimentally observed under certain conditions only.

  6. Concept for Reducing Hall Thruster Chamber Wall Erosion with Lithium Vapor

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Shielding. | Princeton Plasma Physics Lab Concept for Reducing Hall Thruster Chamber Wall Erosion with Lithium Vapor Shielding. Hall thrusters have been established as a compact and reliable means for satellite applications. Erosion of the surfaces of such thrusters, however, has been a serious factor in limiting their lifetimes. Replacing eroded surfaces by replenishing them is generally unattractive because of the mechanical complexity and added weight that could be required. This

  7. Magnetoresistance, electrical conductivity, and Hall effect of glassy carbon

    SciTech Connect (OSTI)

    Baker, D.F.

    1983-02-01

    These properties of glassy carbon heat treated for three hours between 1200 and 2700/sup 0/C were measured from 3 to 300/sup 0/K in magnetic fields up to 5 tesla. The magnetoresistance was generally negative and saturated with reciprocal temperature, but still increased as a function of magnetic field. The maximum negative magnetoresistance measured was 2.2% for 2700/sup 0/C material. Several models based on the negative magnetoresistance being proportional to the square of the magnetic moment were attempted; the best fit was obtained for the simplest model combining Curie and Pauli paramagnetism for heat treatments above 1600/sup 0/C. Positive magnetoresistance was found only in less than 1600/sup 0/C treated glassy carbon. The electrical conductivity, of the order of 200 (ohm-cm)/sup -1/ at room temperature, can be empirically written as sigma = A + Bexp(-CT/sup -1/4) - DT/sup -1/2. The Hall coefficient was independent of magnetic field, insensitive to temperature, but was a strong function of heat treatment temperature, crossing over from negative to positive at about 1700/sup 0/C and ranging from -0.048 to 0.126 cm/sup 3//coul. The idea of one-dimensional filaments in glassy carbon suggested by the electrical conductivity is compatible with the present consensus view of the microstructure.

  8. Fractional quantum Hall junctions and two-channel Kondo models

    SciTech Connect (OSTI)

    Sandler, Nancy P.; Fradkin, Eduardo

    2001-06-15

    A mapping between fractional quantum Hall (FQH) junctions and the two-channel Kondo model is presented. We discuss this relation in detail for the particular case of a junction of a FQH state at {nu}=1/3 and a normal metal. We show that in the strong coupling regime this junction has a non-Fermi-liquid fixed point. At this fixed point the electron Green{close_quote}s function has a branch cut and the impurity entropy is equal to S=1/2ln2. We construct the space of perturbations at the strong coupling fixed point and find that the dimension of the tunneling operator is 1/2. These properties are strongly reminiscent of the non-Fermi-liquid fixed points of a number of quantum impurity models, particularly the two-channel Kondo model. However we have found that, in spite of these similarities, the Hilbert spaces of these two systems are quite different. In particular, although in a special limit the Hamiltonians of both systems are the same, their Hilbert spaces are not since they are determined by physically distinct boundary conditions. As a consequence the spectrum of operators in the two problems is different.

  9. Effects of wall electrodes on Hall effect thruster plasma

    SciTech Connect (OSTI)

    Langendorf, S. Walker, M.; Xu, K.

    2015-02-15

    This paper investigates the physical mechanisms that cause beneficial and detrimental performance effect observed to date in Hall effect thrusters with wall electrodes. It is determined that the wall electrode sheath can reduce ion losses to the wall if positioned near the anode (outside the dense region of the plasma) such that an ion-repelling sheath is able to form. The ability of the wall electrode to form an ion-repelling sheath is inversely proportional to the current drawn—if the wall electrode becomes the dominant sink for the thruster discharge current, increases in wall electrode bias result in increased local plasma potential rather than an ion-repelling sheath. A single-fluid electron flow model gives results that mimic the observed potential structures and the current-sharing fractions between the anode and wall electrodes, showing that potential gradients in the presheath and bulk plasma come at the expense of current draw to the wall electrodes. Secondary electron emission from the wall electrodes (or lack thereof) is inferred to have a larger effect if the electrodes are positioned near the exit plane than if positioned near the anode, due to the difference in energy deposition from the plasma.

  10. Habitat Restoration/Enhancement Fort Hall Reservation : 2008 Annual Report.

    SciTech Connect (OSTI)

    Osborne, Hunter

    2009-07-23

    Habitat enhancement, protection and monitoring were the focus of the Resident Fisheries Program during 2008. Enhancement and protection included sloping, fencing and planting wetlands plugs at sites on Spring Creek (Head-waters). Many previously constructed instream structures (rock barbs and wing dams) were repaired throughout the Fort Hall Indian Reservation (Reservation). Physical sampling during 2008 included sediment and depth measurements (SADMS) in Spring Creek at the Car Removal site. SADMS, used to track changes in channel morphology and specifically track movements of silt through Bottoms stream systems were completed for 5 strata on Spring Creek. Water temperature and chemistry were monitored monthly on Spring Creek, Clear Creek, Diggie Creek, and Portneuf (Jimmy Drinks) and Blackfoot rivers. Fish population densities and biomass were sampled in five reservation streams which included nine sites. Sampling protocols were identical to methods used in past years. Numbers of fish in Spring Creek series remained relatively low, however, there was an increase of biomass overall since 1993. Salmonid fry densities were monitored near Broncho Bridge and were similar to 2006, and 2007, however, as in years past, high densities of macrophytes make it very difficult to see fry in addition to lack of field technicians. Mean catch rate by anglers on Bottoms streams stayed the same as 2007 at 1.5/hr. Numbers of fish larger than 18-inches caught by anglers increased from 2007 at .20 to .26/hr.

  11. Onset of fast reconnection in Hall magnetohydrodynamics mediated by the plasmoid instability

    SciTech Connect (OSTI)

    Huang Yimin; Bhattacharjee, A.; Sullivan, Brian P.

    2011-07-15

    The role of a super-Alfvenic plasmoid instability in the onset of fast reconnection is studied by means of the largest Hall magnetohydrodynamics simulations to date, with system sizes up to 10{sup 4} ion skin depths (d{sub i}). It is demonstrated that the plasmoid instability can facilitate the onset of rapid Hall reconnection, in a regime where the onset would otherwise be inaccessible because the Sweet-Parker width is significantly above d{sub i}. However, the topology of Hall reconnection is not inevitably a single stable X-point. There exists an intermediate regime where the single X-point topology itself exhibits instability, causing the system to alternate between a single X-point geometry and an extended current sheet with multiple X-points produced by the plasmoid instability. Through a series of simulations with various system sizes relative to d{sub i}, it is shown that system size affects the accessibility of the intermediate regime. The larger the system size is, the easier it is to realize the intermediate regime. Although our Hall magnetohydrodynamics (MHD) model lacks many important physical effects included in fully kinetic models, the fact that a single X-point geometry is not inevitable raises the interesting possibility for the first time that Hall MHD simulations may have the potential to realize reconnection with geometrical features similar to those seen in fully kinetic simulations, namely, extended current sheets and plasmoid formation.

  12. Magnetic shielding of Hall thrusters at high discharge voltages

    SciTech Connect (OSTI)

    Mikellides, Ioannis G. Hofer, Richard R.; Katz, Ira; Goebel, Dan M.

    2014-08-07

    A series of numerical simulations and experiments have been performed to assess the effectiveness of magnetic shielding in a Hall thruster operating in the discharge voltage range of 300–700 V (I{sub sp} ≈ 2000–2700 s) at 6 kW, and 800 V (I{sub sp} ≈ 3000) at 9 kW. At 6 kW, the magnetic field topology with which highly effective magnetic shielding was previously demonstrated at 300 V has been retained for all other discharge voltages; only the magnitude of the field has been changed to achieve optimum thruster performance. It is found that magnetic shielding remains highly effective for all discharge voltages studied. This is because the channel is long enough to allow hot electrons near the channel exit to cool significantly upon reaching the anode. Thus, despite the rise of the maximum electron temperature in the channel with discharge voltage, the electrons along the grazing lines of force remain cold enough to eliminate or reduce significantly parallel gradients of the plasma potential near the walls. Computed maximum erosion rates in the range of 300–700 V are found not to exceed 10{sup −2} mm/kh. Such rates are ∼3 orders of magnitude less than those observed in the unshielded version of the same thruster at 300 V. At 9 kW and 800 V, saturation of the magnetic circuit did not allow for precisely the same magnetic shielding topology as that employed during the 6-kW operation since this thruster was not designed to operate at this condition. Consequently, the maximum erosion rate at the inner wall is found to be ∼1 order of magnitude higher (∼10{sup −1} mm/kh) than that at 6 kW. At the outer wall, the ion energy is found to be below the sputtering yield threshold so no measurable erosion is expected.

  13. Fractional quantum Hall effect at Landau level filling ν = 4/11

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pan, W.; Baldwin, K. W.; West, K. W.; Pfeiffer, L. N.; Tsui, D. C.

    2015-01-09

    In this study, we report low temperature electronic transport results on the fractional quantum Hall effect of composite fermions at Landau level filling ν = 4/11 in a very high mobility and low density sample. Measurements were carried out at temperatures down to 15mK, where an activated magnetoresistance Rxx and a quantized Hall resistance Rxy, within 1% of the expected value of h/(4/11)e2, were observed. The temperature dependence of the Rxx minimum at 4/11 yields an activation energy gap of ~ 7 mK. Developing Hall plateaus were also observed at the neighboring states at ν = 3/8 and 5/13.

  14. Experimental Observation of the Inverse Spin Hall Effect at Room Temperature

    SciTech Connect (OSTI)

    Liu, Baoli; Shi, Junren; Wang, Wenxin; Zhao, Hongming; Li, Dafang; Zhang, Shoucheng; Xue, Qikun; Chen, Dongmin; /Beijing, Inst. Phys.

    2010-03-16

    We observe the inverse spin Hall effect in a two-dimensional electron gas confined in Al-GaAs/InGaAs quantum wells. Specifically, they find that an inhomogeneous spin density induced by the optical injection gives rise to an electric current transverse to both the spin polarization and its gradient. The spin Hall conductivity can be inferred from such a measurement through the Einstein relation and the onsager relation, and is found to have the order of magnitude of 0.5(e{sup 2}/h). The observation is made at the room temperature and in samples with macroscopic sizes, suggesting that the inverse spin Hall effects is a robust macroscopic transport phenomenon.

  15. Driving and detecting ferromagnetic resonance in insulators with the spin Hall effect.

    SciTech Connect (OSTI)

    Sklenar, Joseph; Zhang, Wei; Jungfleisch, Matthias B.; Jiang, Wanjun; Chang, Houchen; Pearson, John E.; Wu, Mingzhong; Ketterson, John B.; Hoffmann, Axel

    2015-11-06

    We demonstrate the generation and detection of spin-torque ferromagnetic resonance in Pt/Y3Fe5O12 (YIG) bilayers. A unique attribute of this system is that the spin Hall effect lies at the heart of both the generation and detection processes and no charge current is passing through the insulating magnetic layer. When the YIG undergoes resonance, a dc voltage is detected longitudinally along the Pt that can be described by two components. One is the mixing of the spin Hall magnetoresistance with the microwave current. The other results from spin pumping into the Pt being converted to a dc current through the inverse spin Hall effect. The voltage is measured with applied magnetic field directions that range in-plane to nearly perpendicular. We find that for magnetic fields that are mostly out-of-plane, an imaginary component of the spin mixing conductance is required to model our data.

  16. Ultra-sensitive Hall sensors based on graphene encapsulated in hexagonal boron nitride

    SciTech Connect (OSTI)

    Dauber, Jan; Stampfer, Christoph; Sagade, Abhay A.; Neumaier, Daniel; Oellers, Martin; Watanabe, Kenji; Taniguchi, Takashi

    2015-05-11

    The encapsulation of graphene in hexagonal boron nitride provides graphene on substrate with excellent material quality. Here, we present the fabrication and characterization of Hall sensor elements based on graphene boron nitride heterostructures, where we gain from high mobility and low charge carrier density at room temperature. We show a detailed device characterization including Hall effect measurements under vacuum and ambient conditions. We achieve a current- and voltage-related sensitivity of up to 5700 V/AT and 3 V/VT, respectively, outpacing state-of-the-art silicon and III/V Hall sensor devices. Finally, we extract a magnetic resolution limited by low frequency electric noise of less than 50 nT/√(Hz) making our graphene sensors highly interesting for industrial applications.

  17. Engineering the quantum anomalous Hall effect in graphene with uniaxial strains

    SciTech Connect (OSTI)

    Diniz, G. S. Guassi, M. R.; Qu, F.

    2013-12-28

    We theoretically investigate the manipulation of the quantum anomalous Hall effect (QAHE) in graphene by means of the uniaxial strain. The values of Chern number and Hall conductance demonstrate that the strained graphene in presence of Rashba spin-orbit coupling and exchange field, for vanishing intrinsic spin-orbit coupling, possesses non-trivial topological phase, which is robust against the direction and modulus of the strain. Besides, we also find that the interplay between Rashba and intrinsic spin-orbit couplings results in a topological phase transition in the strained graphene. Remarkably, as the strain strength is increased beyond approximately 7%, the critical parameters of the exchange field for triggering the quantum anomalous Hall phase transition show distinct behaviors—decrease (increase) for strains along zigzag (armchair) direction. Our findings open up a new platform for manipulation of the QAHE by an experimentally accessible strain deformation of the graphene structure, with promising application on novel quantum electronic devices with high efficiency.

  18. Quantum Hall effect in semiconductor systems with quantum dots and antidots

    SciTech Connect (OSTI)

    Beltukov, Ya. M.; Greshnov, A. A.

    2015-04-15

    The integer quantum Hall effect in systems of semiconductor quantum dots and antidots is studied theoretically as a factor of temperature. It is established that the conditions for carrier localization in quantum-dot systems favor the observation of the quantum Hall effect at higher temperatures than in quantum-well systems. The obtained numerical results show that the fundamental plateau corresponding to the transition between the ground and first excited Landau levels can be retained up to a temperature of T ∼ 50 K, which is an order of magnitude higher than in the case of quantum wells. Implementation of the quantum Hall effect at such temperatures requires quantum-dot systems with controllable characteristics, including the optimal size and concentration and moderate geometrical and composition fluctuations. In addition, ordered arrangement is desirable, hence quantum antidots are preferable.

  19. Fractional quantum Hall effect at Landau level filling ν = 4/11

    SciTech Connect (OSTI)

    Pan, W.; Baldwin, K. W.; West, K. W.; Pfeiffer, L. N.; Tsui, D. C.

    2015-01-09

    In this study, we report low temperature electronic transport results on the fractional quantum Hall effect of composite fermions at Landau level filling ν = 4/11 in a very high mobility and low density sample. Measurements were carried out at temperatures down to 15mK, where an activated magnetoresistance Rxx and a quantized Hall resistance Rxy, within 1% of the expected value of h/(4/11)e2, were observed. The temperature dependence of the Rxx minimum at 4/11 yields an activation energy gap of ~ 7 mK. Developing Hall plateaus were also observed at the neighboring states at ν = 3/8 and 5/13.

  20. Spin Hall magnetoresistance in CoFe2O4/Pt films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wu, Hao; Qintong, Zhang; Caihua, Wan; Ali, Syed Shahbaz; Yuan, Zhonghui; You, Lu; Wang, Junling; Choi, Yongseong; Han, Xiufeng

    2015-05-13

    Pulse laser deposition and magnetron sputtering techniques have been employed to prepare MgO(001)//CoFe2O4/Pt samples. Cross section transmission electron microscope results prove that the CoFe2O4 film epitaxially grew along (001) direction. X-ray magnetic circular dichroism results show that magnetic proximity effect in this sample is negligible. Magnetoresistance (MR) properties confirm that spin Hall MR (SMR) dominates in this system. Spin Hall effect-induced anomalous Hall voltage was also observed in this sample. Lastly, these results not only demonstrate the universality of SMR effect but also demonstrate the utility in spintronics of CoFe2O4 as a new type of magnetic insulator.

  1. Global Hall-MHD simulations of magnetorotational instability in a plasma Couette flow experiment

    SciTech Connect (OSTI)

    Ebrahimi, F.; Lefebvre, B.; Bhattacharjee, A.; Forest, C. B.

    2011-06-15

    Global MHD and Hall-MHD numerical simulations relevant to the Madison plasma Couette flow experiment (MPCX) have been performed using the extended MHD code NIMROD. The MPCX has been constructed to study the magnetorotational instability (MRI) in a plasma. The two-fluid Hall effect, which is relevant to some astrophysical situations such as protostellar disks, is also expected to be important in the MPCX. Here, we first derive the local Hall dispersion relation including viscosity, extending earlier work by Balbus and Terquem [Astrophys. J. 552, 235 (2001)]. The predictions of the local analysis are then compared with nonlocal calculations of linear stability of the MRI for a parameter range relevant to the MPCX. It is found that the MHD stability limit and mode structure are altered by the Hall term, and nonlocal analysis is necessary to obtain quantitatively reliable predictions for MPCX. Two-fluid physics also significantly changes the nonlinear evolution and saturation of the axisymmetric MRI. Both the Reynolds and Maxwell stresses contribute significantly to momentum transport. In the Hall regime, when the magnetic field is parallel to the rotation axis, the Maxwell stress is larger than the Reynolds stress (similar to the MHD regime). However, when the magnetic field is antiparallel to the rotation axis in the Hall regime, the Reynolds stress is much larger than the Maxwell stress. To further study the role of non-axisymmetric modes, we have also carried out fully nonlinear MHD computations. Non-axisymmetric modes play an increasingly important role as the magnetic Reynolds number increases and grow to large amplitudes in a saturated turbulent state.

  2. JLab mourns loss of long-time colleague, Hall B staff scientist and senior

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    YerPI physicist Kim Egiyan | Jefferson Lab long-time colleague, Hall B staff scientist and senior YerPI physicist Kim Egiyan JLab mourns loss of long-time colleague, Hall B staff scientist and senior YerPI physicist Kim Egiyan August 25, 2006 Kim Egiyan Kim Egiyan K.Sh. Egiyan was born on 18 June 1935 in the Armenian village of Mirzik in the Khanlar region of Azerbaijan. Kim attended the Yerevan State University, Yerevan (Armenia) and in 1957, after finishing his studies at the university,

  3. Spin Hall effect-controlled magnetization dynamics in NiMnSb

    SciTech Connect (OSTI)

    Dürrenfeld, P. Ranjbar, M.; Gerhard, F.; Gould, C.; Molenkamp, L. W.; Åkerman, J.

    2015-05-07

    We investigate the influence of a spin current generated from a platinum layer on the ferromagnetic resonance (FMR) properties of an adjacent ferromagnetic layer composed of the halfmetallic half-Heusler material NiMnSb. Spin Hall nano-oscillator devices are fabricated, and the technique of spin torque FMR is used to locally study the magnetic properties as in-plane anisotropies and resonance fields. A change in the FMR linewidth, in accordance with the additional spin torque produced by the spin Hall effect, is present for an applied dc current. For sufficiently large currents, this should yield auto-oscillations, which however are not achievable in the present device geometry.

  4. Experimental evidences of a large extrinsic spin Hall effect in AuW alloy

    SciTech Connect (OSTI)

    Laczkowski, P.; Rojas-Sánchez, J.-C.

    2014-04-07

    We report an experimental study of a gold-tungsten alloy (7 at. % W concentration in Au host) displaying remarkable properties for spintronics applications using both magneto-transport in lateral spin valve devices and spin-pumping with inverse spin Hall effect experiments. A very large spin Hall angle of about 10% is consistently found using both techniques with the reliable spin diffusion length of 2 nm estimated by the spin sink experiments in the lateral spin valves. With its chemical stability, high resistivity, and small induced damping, this AuW alloy may find applications in the nearest future.

  5. Spin-torque switching of a nano-magnet using giant spin hall effect

    SciTech Connect (OSTI)

    Penumatcha, Ashish V. Das, Suprem R.; Chen, Zhihong; Appenzeller, Joerg

    2015-10-15

    The Giant Spin Hall Effect(GSHE) in metals with high spin-orbit coupling is an efficient way to convert charge currents to spin currents, making it well-suited for writing information into magnets in non-volatile magnetic memory as well as spin-logic devices. We demonstrate the switching of an in-plane CoFeB magnet using a combination of GSHE and an external magnetic field. The magnetic field dependence of the critical current is used to estimate the spin hall angle with the help of a thermal activation model for spin-transfer torque switching of a nanomagnet.

  6. Hysteretic magnetoresistance and unconventional anomalous Hall effect in the frustrated magnet TmB4

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sunku, Sai Swaroop; Kong, Tai; Ito, Toshimitsu; Canfield, Paul C.; Shastry, B. Sriram; Sengupta, Pinaki; Panagopoulos, Christos

    2016-05-11

    We study TmB4, a frustrated magnet on the Archimedean Shastry-Sutherland lattice, through magnetization and transport experiments. The lack of anisotropy in resistivity shows that TmB4 is an electronically three-dimensional system. The magnetoresistance (MR) is hysteretic at low temperature even though a corresponding hysteresis in magnetization is absent. The Hall resistivity shows unconventional anomalous Hall effect (AHE) and is linear above saturation despite a large MR. In conclusion, we propose that complex structures at magnetic domain walls may be responsible for the hysteretic MR and may also lead to the AHE.

  7. Equivalence of donor and acceptor fits of temperature dependent Hall carrier density and Hall mobility data: Case of ZnO

    SciTech Connect (OSTI)

    Brochen, Stphane; Feuillet, Guy; Pernot, Julien

    2014-04-28

    In this work, statistical formulations of the temperature dependence of ionized and neutral impurity concentrations in a semiconductor, needed in the charge balance equation and for carrier scattering calculations, have been developed. These formulations have been used in order to elucidate a confusing situation, appearing when compensating acceptor (donor) levels are located sufficiently close to the conduction (valence) band to be thermally ionized and thereby to emit (capture) an electron to (from) the conduction (valence) band. In this work, the temperature dependent Hall carrier density and Hall mobility data adjustments are performed in an attempt to distinguish the presence of a deep acceptor or a deep donor level, coexisting with a shallower donor level and located near the conduction band. Unfortunately, the present statistical developments, applied to an n-type hydrothermal ZnO sample, lead in both cases to consistent descriptions of experimental Hall carrier density and mobility data and thus do not allow to determine the nature, donor or acceptor, of the deep level. This demonstration shows that the emission of an electron in the conduction band, generally assigned to a (0/+1) donor transition from a donor level cannot be applied systematically and could also be attributed to a (?1/0) donor transition from an acceptor level. More generally, this result can be extended for any semiconductor and also for deep donor levels located close to the valence band (acceptor transition)

  8. Newport News School Board Member Hosting Town Hall Thursday (Daily Press) |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Jefferson Lab Newport News School Board Member Hosting Town Hall Thursday (Daily Press) External Link: http://articles.dailypress.com/2012-03-05/news/dp-nws-ednotebook-0305-20120304_1... By jlab_admin on Tue, 2012-03-06

  9. EX/P5-4 Two-Fluid Hall Effect on Plasma Relaxation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    EXP5-4 Two-Fluid Hall Effect on Plasma Relaxation in a High-Temperature Plasma W.X. Ding 1,3), V. Mirnov 2,3), A. F. Almagri 2,3), D.L. Brower 1,3), D. Craig 2,3), B.H. Deng 1,3), ...

  10. Internal plasma potential measurements of a Hall thruster using plasma lens focusing

    SciTech Connect (OSTI)

    Linnell, Jesse A.; Gallimore, Alec D.

    2006-10-15

    Magnetic field topology has been found to be a central design concern for high-efficiency Hall thrusters. For future improvements in Hall thruster design, it is necessary to better understand the effects that magnetic field topology has on the internal plasma structure. The Plasmadynamics and Electric Propulsion Laboratory's High-speed Axial Reciprocating Probe system is used in conjunction with a floating emissive probe to map the internal plasma potential structure of the NASA-173Mv1 Hall thruster [R. R. Hofer, R. S. Jankovsky, and A. D. Gallimore, J. Propul. Power 22, 721 (2006); 22, 732 (2006)]. Measurements are taken at 300 and 500 V with a xenon propellant. Electron temperature and electric field are also measured and reported. The acceleration zone and equipotential lines are found to be strongly linked to the magnetic field lines. Moreover, in some cases the ions are accelerated strongly toward the center of the discharge channel. The agreement between magnetic field lines and equipotential lines is best for high-voltage operation. These results have strong implications on the performance and lifetime optimization of Hall thrusters.

  11. Structure transitions induced by the Hall term in homogeneous and isotropic magnetohydrodynamic turbulence

    SciTech Connect (OSTI)

    Miura, H., E-mail: miura.hideaki@nifs.ac.jp [Department of Helical Plasma Research, National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Araki, K. [Faculty of Engineering, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005 (Japan)

    2014-07-15

    Hall effects on local structures in homogeneous, isotropic, and incompressible magnetohydrodynamic turbulence are studied numerically. The transition of vortices from sheet-like to tubular structures induced by the Hall term is found, while the kinetic energy spectrum does not distinguish the two types of structures. It is shown by the use of the sharp low-pass filter that the transition occurs not only in the scales smaller than the ion skin depth but also in a larger scale. The transition is related with the forward energy transfer in the spectral space. Analyses by the use of the sharp low-pass filter show that the nonlinear energy transfer associated with the Hall term is dominated by the forward transfer and relatively local in the wave number space. A projection of the simulation data to a Smagorinsky-type sub-grid-scale model shows that the high wave number component of the Hall term may possibly be replaced by the model effectively.

  12. Analysis of Impacts of a Clean Energy Standard as requested by Chairman Hall

    Reports and Publications (EIA)

    2011-01-01

    This report responds to a request from Chairman Ralph M. Hall for an analysis of the impacts of a Clean Energy Standard (CES). The request, as outlined in the letter included in Appendix A, sets out specific assumptions and scenarios for the study.

  13. WIPP Employee Inducted Into Mine Rescue Hall of Fame- WIPP Teams Recognized at National Competition

    Broader source: Energy.gov [DOE]

    CARLSBAD, N.M., August 2, 2013 - Long-time Waste Isolation Pilot Plant (WIPP) employee Gary Kessler was inducted into the Metal/Non-Metal National Mine Rescue Hall of Fame on Aug. 1, 2013 at the biennial mine rescue competition in Reno, Nevada.

  14. EECBG Success Story: After 105 Years, Historic City Hall in West Des Moines, Iowa Goes Green

    Broader source: Energy.gov [DOE]

    The city of West Des Moines, Iowa is used funding to renovate the Historic City Hall building located in Valley Junction, including the installation of four geothermal heating wells, a rooftop covered with vegetation, solar panels and permeable pavers to allow stormwater through to the soil below. Learn more.

  15. The impact of Hall physics on magnetized high energy density plasma jets

    SciTech Connect (OSTI)

    Gourdain, P.-A.; Seyler, C. E.; Atoyan, L.; Greenly, J. B.; Hammer, D. A.; Kusse, B. R.; Pikuz, S. A.; Potter, W. M.; Schrafel, P. C.; Shelkovenko, T. A.

    2014-05-15

    Hall physics is often neglected in high energy density plasma jets due to the relatively high electron density of such jets (n{sub e} ∼ 10{sup 19} cm{sup −3}). However, the vacuum region surrounding the jet has much lower densities and is dominated by Hall electric field. This electric field redirects plasma flows towards or away from the axis, depending on the radial current direction. A resulting change in the jet density has been observed experimentally. Furthermore, if an axial field is applied on the jet, the Hall effect is enhanced and ignoring it leads to serious discrepancies between experimental results and numerical simulations. By combining high currents (∼1 MA) and magnetic field helicity (15° angle) in a pulsed power generator such as COBRA, plasma jets can be magnetized with a 10 T axial field. The resulting field enhances the impact of the Hall effect by altering the density profile of current-free plasma jets and the stability of current-carrying plasma jets (e.g., Z-pinches)

  16. A novel method of including Landau level mixing in numerical studies of the quantum Hall effect

    SciTech Connect (OSTI)

    Wooten, Rachel; Quinn, John; Macek, Joseph

    2013-12-04

    Landau level mixing should influence the quantum Hall effect for all except the strongest applied magnetic fields. We propose a simple method for examining the effects of Landau level mixing by incorporating multiple Landau levels into the Haldane pseudopotentials through exact numerical diagonalization. Some of the resulting pseudopotentials for the lowest and first excited Landau levels will be presented.

  17. Edge-channel interferometer at the graphene quantum Hall pn junction

    SciTech Connect (OSTI)

    Morikawa, Sei; Moriya, Rai; Masubuchi, Satoru Machida, Tomoki; Watanabe, Kenji; Taniguchi, Takashi

    2015-05-04

    We demonstrate a quantum Hall edge-channel interferometer in a high-quality graphene pn junction under a high magnetic field. The co-propagating p and n quantum Hall edge channels traveling along the pn interface functions as a built-in Aharonov-Bohm-type interferometer, the interferences in which are sensitive to both the external magnetic field and the carrier concentration. The trajectories of peak and dip in the observed resistance oscillation are well reproduced by our numerical calculation that assumes magnetic flux quantization in the area enclosed by the co-propagating edge channels. Coherent nature of the co-propagating edge channels is confirmed by the checkerboard-like pattern in the dc-bias and magnetic-field dependences of the resistance oscillations.

  18. Magnetic shielding of the channel walls in a Hall plasma accelerator

    SciTech Connect (OSTI)

    Mikellides, Ioannis G.; Katz, Ira; Hofer, Richard R.; Goebel, Dan M.; Grys, Kristi de; Mathers, Alex

    2011-03-15

    In a qualification life test of a Hall thruster it was found that the erosion of the acceleration channel practically stopped after {approx}5600 h. Numerical simulations using a two-dimensional axisymmetric plasma solver with a magnetic field-aligned mesh reveal that when the channel receded from its early-in-life to its steady-state configuration the following changes occurred near the wall: (1) reduction of the electric field parallel to the wall that prohibited ions from acquiring significant impact kinetic energy before entering the sheath, (2) reduction of the potential fall in the sheath that further diminished the total energy ions gained before striking the material, and (3) reduction of the ion number density that decreased the flux of ions to the wall. All these changes, found to have been induced by the magnetic field, constituted collectively an effective shielding of the walls from any significant ion bombardment. Thus, we term this process in Hall thrusters 'magnetic shielding'.

  19. Variational principle for linear stability of flowing plasmas in Hall magnetohydrodynamics

    SciTech Connect (OSTI)

    Hirota, M.; Yoshida, Z.; Hameiri, E.

    2006-02-15

    Linear stability of equilibrium states with flow is studied by means of the variational principle in Hall magnetohydrodynamics (MHD). The Lagrangian representation of the linearized Hall MHD equation is performed by considering special perturbations that preserves some constants of motion (the Casimir invariants). The resultant equation has a Hamiltonian structure which enables the variational principle. There is however some difficulties in showing the positive definiteness of the quadratic form in the presence of flow. The dynamically accessible variation is a more restricted class of perturbations which, by definition, preserves all the Casimir invariants. For such variations, the quadratic form (the second variation of Hamiltonian) can be positive definite. Some conditions for stability are derived by applying this variational principle to the double Beltrami equilibrium.

  20. Determination of the Pt spin diffusion length by spin-pumping and spin Hall effect

    SciTech Connect (OSTI)

    Zhang, Wei; Pearson, John E.; Hoffmann, Axel; Vlaminck, Vincent; Divan, Ralu; Bader, Samuel D.

    2013-12-09

    The spin diffusion length of Pt at room temperature and at 8 K is experimentally determined via spin pumping and spin Hall effect in permalloy/Pt bilayers. Voltages generated during excitation of ferromagnetic resonance from the inverse spin Hall effect and anisotropic magnetoresistance effect were investigated with a broadband approach. Varying the Pt layer thickness gives rise to an evolution of the voltage line shape due to the superposition of the above two effects. By studying the ratio of the two voltage components with the Pt layer thickness, the spin diffusion length of Pt can be directly extracted. We obtain a spin diffusion length of ∼1.2 nm at room temperature and ∼1.6 nm at 8 K.

  1. Realization of tunable spin-dependent splitting in intrinsic photonic spin Hall effect

    SciTech Connect (OSTI)

    Ling, Xiaohui; Yi, Xunong; Zhou, Xinxing; Liu, Yachao; Shu, Weixing; Wen, Shuangchun; Luo, Hailu

    2014-10-13

    We report the realization of tunable spin-dependent splitting in intrinsic photonic spin Hall effect. By breaking the rotational symmetry of a cylindrical vector beam, the intrinsic vortex phases that the two spin components of the vector beam carries, which is similar to the geometric Pancharatnam-Berry phase, are no longer continuous in the azimuthal direction, and leads to observation of spin accumulation at the opposite edge of the beam. Due to the inherent nature of the phase and independency of light-matter interaction, the observed photonic spin Hall effect is intrinsic. Modulating the topological charge of the vector beam, the spin-dependent splitting can be enhanced and the direction of spin accumulation is switchable. Our findings may provide a possible route for generation and manipulation of spin-polarized photons, and enables spin-based photonics applications.

  2. Sheath oscillation characteristics and effect on near-wall conduction in a krypton Hall thruster

    SciTech Connect (OSTI)

    Zhang, Fengkui Kong, Lingyi; Li, Chenliang; Yang, Haiwei; Li, Wei

    2014-11-15

    Despite its affordability, the krypton Hall-effect thruster in applications always had problems in regard to performance. The reason for this degradation is studied from the perspective of the near-wall conductivity of electrons. Using the particle-in-cell method, the sheath oscillation characteristics and its effect on near-wall conduction are compared in the krypton and xenon Hall-effect thrusters both with wall material composed of BNSiO{sub 2}. Comparing these two thrusters, the sheath in the krypton-plasma thruster will oscillate at low electron temperatures. The near-wall conduction current is only produced by collisions between electrons and wall, thereby causing a deficiency in the channel current. The sheath displays spatial oscillations only at high electron temperature; electrons are then reflected to produce the non-oscillation conduction current needed for the krypton-plasma thruster. However, it is accompanied with intensified oscillations.

  3. Chemical reaction at ferromagnet/oxide interface and its influence on anomalous Hall effect

    SciTech Connect (OSTI)

    Liu, Yi-Wei; Teng, Jiao E-mail: ghyu@mater.ustb.edu.cn; Zhang, Jing-Yan; Liu, Yang; Chen, Xi; Li, Xu-Jing; Feng, Chun; Wang, Hai-Cheng; Li, Ming-Hua; Yu, Guang-Hua E-mail: ghyu@mater.ustb.edu.cn; Wu, Zheng-Long

    2014-09-08

    Chemical reactions at the ferromagnet/oxide interface in [Pt/Fe]{sub 3}/MgO and [Pt/Fe]{sub 3}/SiO{sub 2} multilayers before and after annealing were investigated by X-ray photoelectron spectroscopy. The results show that Fe atoms at the Fe/MgO interface were completely oxidized in the as-grown state and significantly deoxidized after vacuum annealing. However, only some of the Fe atoms at the Fe/SiO{sub 2} interface were oxidized and rarely deoxidized after annealing. The anomalous Hall effect was modified by this interfacial chemical reaction. The saturation anomalous Hall resistance (R{sub xy}) was greatly increased in the [Pt/Fe]{sub 3}/MgO multilayers after annealing and was 350% higher than that in the as-deposited film, while R{sub xy} of the [Pt/Fe]{sub 3}/SiO{sub 2} multilayer only increased 10% after annealing.

  4. Spin pumping and inverse spin Hall effects—Insights for future spin-orbitronics (invited)

    SciTech Connect (OSTI)

    Zhang, Wei Jungfleisch, Matthias B.; Jiang, Wanjun; Fradin, Frank Y.; Pearson, John E.; Hoffmann, Axel; Sklenar, Joseph; Ketterson, John B.

    2015-05-07

    Quantification of spin-charge interconversion has become increasingly important in the fast-developing field of spin-orbitronics. Pure spin current generated by spin pumping acts as a sensitive probe for many bulk and interface spin-orbit effects, which has been indispensable for the discovery of many promising new spin-orbit materials. We apply spin pumping and inverse spin Hall effect experiments, as a useful metrology, and study spin-orbit effects in a variety of metals and metal interfaces. We quantify the spin Hall effects in Ir and W using the conventional bilayer structures and discuss the self-induced voltage in a single layer of ferromagnetic permalloy. Finally, we extend our discussions to multilayer structures and quantitatively reveal the spin current flow in two consecutive normal metal layers.

  5. Quantum corrections to conductivity under conditions of the integer quantum Hall effect

    SciTech Connect (OSTI)

    Greshnov, A. A.

    2012-06-15

    Quantum corrections to the conductivity of a two-dimensional electron gas under conditions of the integer quantum Hall effect have been studied. It is shown that violation of the one-parameter scaling under conditions of quantizing magnetic fields, {omega}{sub c}{tau} Much-Greater-Than 1, occurs at a level of the perturbation theory. The results of diagrammatic calculation of the quantum correction are in agreement with the numerical dependences of the peaks in the longitudinal conductivity on the effective size of the sample, in contrast to earlier calculations based on the unitary nonlinear {sigma}-model. Due to this, consideration of Landau quantization represents a criterion for correct description of the quantum Hall effect.

  6. Enhanced spin Hall effect by electron correlations in CuBi alloys

    SciTech Connect (OSTI)

    Gu, Bo Xu, Zhuo; Mori, Michiyasu; Maekawa, Sadamichi; Ziman, Timothy

    2015-05-07

    A recent experiment in CuBi alloys obtained a large spin Hall angle (SHA) of −0.24 (Niimi et al., Phys. Rev. Lett. 109, 156602 (2012)). We find that the SHA can be dramatically enhanced by Bi impurities close to the Cu surface. The mechanisms of this enhancement are two-fold. One is that the localized impurity state on surface has a decreased hybridization and combined with Coulomb correlation effect. The other comes from the low-dimensional state of conduction electrons on surface, which results in a further enhancement of skew scattering by impurities. Furthermore, we note that a discrepancy in sign of SHA between the experiment and previous theories is simply caused by different definitions of SHA. This re-establishes skew scattering as the essential mechanism underlying the spin Hall effect in CuBi alloys.

  7. Hall effect in the extremely large magnetoresistance semimetal WTe{sub 2}

    SciTech Connect (OSTI)

    Luo, Yongkang Dai, Y. M.; Taylor, A. J.; Yarotski, D. A.; Prasankumar, R. P.; Thompson, J. D.; Li, H.; Miao, H.; Shi, Y. G.; Ding, H.

    2015-11-02

    We systematically measured the Hall effect in the extremely large magnetoresistance semimetal WTe{sub 2}. By carefully fitting the Hall resistivity to a two-band model, the temperature dependencies of the carrier density and mobility for both electron- and hole-type carriers were determined. We observed a sudden increase in the hole density below ∼160 K, which is likely associated with the temperature-induced Lifshitz transition reported by a previous photoemission study. In addition, a more pronounced reduction in electron density occurs below 50 K, giving rise to comparable electron and hole densities at low temperature. Our observations indicate a possible electronic structure change below 50 K, which might be the direct driving force of the electron-hole “compensation” and the extremely large magnetoresistance as well. Numerical simulations imply that this material is unlikely to be a perfectly compensated system.

  8. Minimum energy states of the cylindrical plasma pinch in single-fluid and Hall magnetohydrodynamics

    SciTech Connect (OSTI)

    Khalzov, I. V.; Schnack, D. D.; Mirnov, V. V.; Ebrahimi, F.

    2012-01-15

    Relaxed states of a plasma column are found analytically in single-fluid and Hall magnetohydrodynamics (MHD). We perform complete minimization of the energy with constraints imposed by invariants inherent in the corresponding models. It is shown that the relaxed state in Hall MHD is a force-free magnetic field with uniform axial flow and/or rigid azimuthal rotation. In contrast, the relaxed states in single-fluid MHD are more complex due to the coupling between velocity and magnetic field. Cylindrically and helically symmetric relaxed states are considered for both models. Helical states may be time dependent and analogous to helical waves, propagating on a cylindrically symmetric background. Application of our results to reversed-field pinches (RFP) is discussed. The radial profile of the parallel momentum predicted by the single-fluid MHD relaxation theory is shown to be in reasonable agreement with experimental observation from the Madison symmetric torus RFP experiment.

  9. The Honorable Rudolph Giuliani City Hall New York, New York 10007

    Office of Legacy Management (LM)

    Deparhent of Eneigy Washington, DC 20585 ,, , The Honorable Rudolph Giuliani City Hall New York, New York 10007 Dear Mayor Giuljani: :. / Secretary of Energy Hazel O'Leary has announced- a new approach to opennes ', -the Department of Energy (DOE).and,its communications with the public.- I support of this initiative, we are pleased to forward the enclosed inforo related to the Ledoux and Co. site in your jurisdiction that performed wa for DOE's predecessor agencies. 'information, use, and

  10. 06.27.14 SRS Retirees Town Hall Meeting Q/A Period Summary Page 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Meeting Q/A Period Summary Page 1 NOTICE: SRSRA TOWN HALL MEETING QUESTION/ANSWER PERIOD SUMMARY New Ellenton Community Center JUNE 27, 2014 *105 in Attendance *Meeting Agenda & Handout available  Dave Moody, DOE-SR Manager  John Veldman, SRS Retirees Association (SRSRA) Board  Dave Hepner, DOE-SR Acquisitions Operations Division Director  Carol Barry, SRNS Benefits Q: Why are their 2 columns on the chart (referencing handout)? A: Left column is ERISA minimum, which is the

  11. Microsoft PowerPoint - Town Hall Slides 5-15-14 rev.0

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    15, 2014 Meeting Agenda * Opening Comments - Mayor Janway * Panel Member Introductions - John Heaton (Moderator) * CBFO Manager Remarks - Dana Bryson * Update on Phase 3 Activities - Tammy Reynolds * May 10 Entry * Today's Entry * Ventilation System Status * Close-out of Bioassay Program - Jim Stafford * Audience Questions * One question at a time please OPENING COMMENTS Dana Bryson, CBFO Deputy Manager This Week's Events * Joe Franco in Washington * Town Hall Agenda * May 10 and May 15 Entries

  12. Microsoft PowerPoint - Town_Hall_Slides_3_5_15_Final

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carlsbad Town Hall Meeting Sponsored by the U.S. Department of Energy and the City of Carlsbad, NM March 5, 2015 www.energy.gov/EM 2 Agenda * Opening Comments - Mayor Dale Janway * Update on CBFO and WIPP activities - Dana Bryson * Recovery Status - Tammy Reynolds * Radiological Contamination - Jim Blankenhorn * Audience Questions * In house * Internet * Closing Comments - Dana Bryson www.energy.gov/EM 3 Update on CBFO and WIPP Activities Dana Bryson, CBFO Deputy Manager www.energy.gov/EM 4 *

  13. A spin-filter made of quantum anomalous Hall insulator nanowires

    SciTech Connect (OSTI)

    Wu, Jiansheng

    2014-07-28

    Topological end states (TES) in quantum anomalous Hall insulator nanowires can induce tunneling within the gap. Such TES are spin polarized, thus the induced current is spin polarized as well, which can be used to construct a spin-filter applied in spintronics. An interferometry device is designed to control the polarized current as well. The advantage and finite size effect on this system are discussed.

  14. Internal plasma potential measurements of a Hall thruster using xenon and krypton propellant

    SciTech Connect (OSTI)

    Linnell, Jesse A.; Gallimore, Alec D.

    2006-09-15

    For krypton to become a realistic option for Hall thruster operation, it is necessary to understand the performance gap between xenon and krypton and what can be done to reduce it. A floating emissive probe is used with the Plasmadynamics and Electric Propulsion Laboratory's High-speed Axial Reciprocating Probe system to map the internal plasma potential structure of the NASA-173Mv1 Hall thruster [R. R. Hofer, R. S. Jankovsky, and A. D. Gallimore, J. Propulsion Power 22, 721 (2006); and ibid.22, 732 (2006)] using xenon and krypton propellant. Measurements are taken for both propellants at discharge voltages of 500 and 600 V. Electron temperatures and electric fields are also reported. The acceleration zone and equipotential lines are found to be strongly linked to the magnetic-field lines. The electrostatic plasma lens of the NASA-173Mv1 Hall thruster strongly focuses the xenon ions toward the center of the discharge channel, whereas the krypton ions are defocused. Krypton is also found to have a longer acceleration zone than the xenon cases. These results explain the large beam divergence observed with krypton operation. Krypton and xenon have similar maximum electron temperatures and similar lengths of the high electron temperature zone, although the high electron temperature zone is located farther downstream in the krypton case.

  15. Hall-effect-controlled gas dynamics in protoplanetary disks. I. Wind solutions at the inner disk

    SciTech Connect (OSTI)

    Bai, Xue-Ning

    2014-08-20

    The gas dynamics of protoplanetary disks (PPDs) is largely controlled by non-ideal magnetohydrodynamic (MHD) effects including Ohmic resistivity, the Hall effect, and ambipolar diffusion. Among these the role of the Hall effect is the least explored and most poorly understood. In this series, we have included, for the first time, all three non-ideal MHD effects in a self-consistent manner to investigate the role of the Hall effect on PPD gas dynamics using local shearing-box simulations. In this first paper, we focus on the inner region of PPDs, where previous studies (Bai and Stone 2013; Bai 2013) excluding the Hall effect have revealed that the inner disk up to ∼10 AU is largely laminar, with accretion driven by a magnetocentrifugal wind. We confirm this basic picture and show that the Hall effect modifies the wind solutions depending on the polarity of the large-scale poloidal magnetic field B{sub 0} threading the disk. When B{sub 0}⋅Ω>0, the horizontal magnetic field is strongly amplified toward the disk interior, leading to a stronger disk wind (by ∼50% or less in terms of the wind-driven accretion rate). The enhanced horizontal field also leads to much stronger large-scale Maxwell stress (magnetic braking) that contributes to a considerable fraction of the wind-driven accretion rate. When B{sub 0}⋅Ω<0, the horizontal magnetic field is reduced, leading to a weaker disk wind (by ≲ 20%) and negligible magnetic braking. Under fiducial parameters, we find that when B{sub 0}⋅Ω>0, the laminar region extends farther to ∼10-15 AU before the magnetorotational instability sets in, while for B{sub 0}⋅Ω<0, the laminar region extends only to ∼3-5 AU for a typical accretion rate of ∼10{sup –8} to10{sup –7} M {sub ☉} yr{sup –1}. Scaling relations for the wind properties, especially the wind-driven accretion rate, are provided for aligned and anti-aligned field geometries.

  16. In-plane current induced domain wall nucleation and its stochasticity in perpendicular magnetic anisotropy Hall cross structures

    SciTech Connect (OSTI)

    Sethi, P.; Murapaka, C.; Lim, G. J.; Lew, W. S.

    2015-11-09

    Hall cross structures in magnetic nanowires are commonly used for electrical detection of magnetization reversal in which a domain wall (DW) is conventionally nucleated by a local Oersted field. In this letter, we demonstrate DW nucleation in Co/Ni perpendicular magnetic anisotropy nanowire at the magnetic Hall cross junction. The DWs are nucleated by applying an in-plane pulsed current through the nanowire without the need of a local Oersted field. The change in Hall resistance, detected using anomalous Hall effect, is governed by the magnetic volume switched at the Hall junction, which can be tuned by varying the magnitude of the applied current density and pulse width. The nucleated DWs are driven simultaneously under the spin transfer torque effect when the applied current density is above a threshold. The possibility of multiple DW generation and variation in magnetic volume switched makes nucleation process stochastic in nature. The in-plane current induced stochastic nature of DW generation may find applications in random number generation.

  17. Magnetic shielding of a laboratory Hall thruster. I. Theory and validation

    SciTech Connect (OSTI)

    Mikellides, Ioannis G. Katz, Ira; Hofer, Richard R.; Goebel, Dan M.

    2014-01-28

    We demonstrate a technique by which erosion of the acceleration channel in Hall thrusters can be reduced by at least a few orders of magnitude. The first principles of the technique, now known as “magnetic shielding,” have been derived based on the findings of 2-D numerical simulations. The simulations, in turn, guided the modification of an existing 6-kW laboratory Hall thruster to test the theory and are the main subject of this Part I article. Part II expands on the results of the experiments. Near the walls of the magnetically shielded (MS) thruster theory and experiment agree that (1) the plasma potential has been sustained at values near the discharge voltage, and (2) the electron temperature has been lowered compared to the unshielded thruster. Erosion rates deduced directly from the wall probes show reductions of at least ∼3 orders of magnitude at the MS inner wall when an ion energy threshold of 30.5 V is used in the sputtering yield model of the channel material. At the outer wall the probes reveal that the ion energy was below the assumed threshold. Using a threshold of 25 V, the simulations predict a minimum reduction of ∼600 at the MS inner wall. At the MS outer wall ion energies are found to be below 25 V. When a 50-V threshold is used the computed ion energies are below the threshold at both sides of the channel. Uncertainties, sensitivities, and differences between theory and experiment are also discussed. The elimination of wall erosion in Hall thrusters solves a problem that has remained unsettled for more than five decades.

  18. Field effect in the quantum Hall regime of a high mobility graphene wire

    SciTech Connect (OSTI)

    Barraud, C., E-mail: cbarraud@phys.ethz.ch, E-mail: clement.barraud@univ-paris-diderot.fr; Choi, T.; Ihn, T.; Ensslin, K. [Solid State Physics Laboratory, ETH Zrich, CH-8093 Zrich (Switzerland); Butti, P.; Shorubalko, I. [Swiss Federal Laboratories of Materials Science and Technologies, EMPA Elect. Metrol. Reliabil. Lab., CH-8600 Dbendorf (Switzerland); Taniguchi, T.; Watanabe, K. [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2014-08-21

    In graphene-based electronic devices like in transistors, the field effect applied thanks to a gate electrode allows tuning the charge density in the graphene layer and passing continuously from the electron to the hole doped regime across the Dirac point. Homogeneous doping is crucial to understand electrical measurements and for the operation of future graphene-based electronic devices. However, recently theoretical and experimental studies highlighted the role of the electrostatic edge due to fringing electrostatic field lines at the graphene edges [P. Silvestrov and K. Efetov, Phys. Rev. B 77, 155436 (2008); F. T. Vasko and I. V. Zozoulenko, Appl. Phys. Lett. 97, 092115 (2010)]. This effect originates from the particular geometric design of the samples. A direct consequence is a charge accumulation at the graphene edges giving a value for the density, which deviates from the simple picture of a plate capacitor and also varies along the width of the graphene sample. Entering the quantum Hall regime would, in principle, allow probing this accumulation thanks to the extreme sensitivity of this quantum effect to charge density and the charge distribution. Moreover, the presence of an additional and counter-propagating edge channel has been predicted [P. Silvestrov and K. Efetov, Phys. Rev. B 77, 155436 (2008)] giving a fundamental aspect to this technological issue. In this article, we investigate this effect by tuning a high mobility graphene wire into the quantum Hall regime in which charge carriers probe the electrostatic potential at high magnetic field close to the edges. We observe a slight deviation to the linear shift of the quantum Hall plateaus with magnetic field and we study its evolution for different filling factors, which correspond to different probed regions in real space. We discuss the possible origins of this effect including an increase of the charge density towards the edges.

  19. Invited Article: An integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument

    SciTech Connect (OSTI)

    Kühne, P. Schubert, M. Hofmann, T.; Herzinger, C. M. Woollam, J. A.

    2014-07-15

    We report on the development of the first integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument, covering an ultra wide spectral range from 3 cm{sup −1} to 7000 cm{sup −1} (0.1–210 THz or 0.4–870 meV). The instrument comprises four sub-systems, where the magneto-cryostat-transfer sub-system enables the usage of the magneto-cryostat sub-system with the mid-infrared ellipsometer sub-system, and the far-infrared/terahertz ellipsometer sub-system. Both ellipsometer sub-systems can be used as variable angle-of-incidence spectroscopic ellipsometers in reflection or transmission mode, and are equipped with multiple light sources and detectors. The ellipsometer sub-systems are operated in polarizer-sample-rotating-analyzer configuration granting access to the upper left 3 × 3 block of the normalized 4 × 4 Mueller matrix. The closed cycle magneto-cryostat sub-system provides sample temperatures between room temperature and 1.4 K and magnetic fields up to 8 T, enabling the detection of transverse and longitudinal magnetic field-induced birefringence. We discuss theoretical background and practical realization of the integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument, as well as acquisition of optical Hall effect data and the corresponding model analysis procedures. Exemplarily, epitaxial graphene grown on 6H-SiC, a tellurium doped bulk GaAs sample and an AlGaN/GaN high electron mobility transistor structure are investigated. The selected experimental datasets display the full spectral, magnetic field and temperature range of the instrument and demonstrate data analysis strategies. Effects from free charge carriers in two dimensional confinement and in a volume material, as well as quantum mechanical effects (inter-Landau-level transitions) are observed and discussed exemplarily.

  20. The Honoradle':Rudolf Juiliani City'Hall New York, New York I0007

    Office of Legacy Management (LM)

    1 / .' Department oft Endrgy :. ' . ' . Wasthgton, DC 20585 ' ,,' . .' . . _ s ,' FEi,l 6 jg& ,. . . ' I s. i ,-' .' / ,, -. ,. The Honoradle':Rudolf Juiliani City'Hall New York, New York I0007 i ', 1" Dear MayorJuilianiz ,. : ", ,. Secretary'of,Energy,Hazel O'Leary has announced a new approach to openness'in the, Department of Energy (DOE)and its communications with the public-~ :'In support of this initiative,, we are pleased to .forward,the'enclpsed. information related.to the

  1. AC-magnetotransport of a 2DEG in the quantum Hall regime

    SciTech Connect (OSTI)

    Hernndez, C.; Chaubet, C.

    2014-05-15

    In this paper we present an ac-magneto-transport study of a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime, for frequencies in the range [100Hz, 1MHz]. We present a new approach to understand admittance measurements based in the Landauer-Buttiker formalism for QHE edge channels and taking into account the capacitance and the topology of the cables connected to the contacts used in the measurements. Our model predicts an universal behavior with the a-dimensional parameter RC? where R is the 2 wires resistance of the 2DEG, C the capacitance cables and the angular frequency, in agreement with experiments.

  2. Ion dynamics in an E × B Hall plasma accelerator

    SciTech Connect (OSTI)

    Young, Christopher V. Lucca Fabris, Andrea; Cappelli, Mark A.

    2015-01-26

    We show the time evolution of the ion velocity distribution function in a Hall plasma accelerator during a 20 kHz natural, quasi-periodic plasma oscillation. We apply a time-synchronized laser induced fluorescence technique at different locations along the channel midline, obtaining time- and spatially resolved ion velocity measurements. Strong velocity and density fluctuations and multiple ion populations are observed throughout the so-called “breathing mode” ionization instability, opening an experimental window into the detailed ion dynamics and physical processes at the heart of such devices.

  3. Upgraded photon calorimeter with integrating readout for Hall A Compton Polarimeter at Jefferson Lab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Friend, M.; Parno, D.; Benmokhtar, F.; Camsonne, A.; Dalton, M. M.; Franklin, G. B.; Mamyan, V.; Michaels, R.; Nanda, S.; Nelyubin, V.; et al

    2012-06-01

    The photon arm of the Compton polarimeter in Hall A of Jefferson Lab has been upgraded to allow for electron beam polarization measurements with better than 1% accuracy. The data acquisition system (DAQ) now includes an integrating mode, which eliminates several systematic uncertainties inherent in the original counting-DAQ setup. The photon calorimeter has been replaced with a Ce-doped Gd2SiO5 crystal, which has a bright output and fast response, and works well for measurements using the new integrating method at electron beam energies from 1 to 6 GeV.

  4. Influence of oblique magnetic field on electron cross-field transport in a Hall effect thruster

    SciTech Connect (OSTI)

    Miedzik, Jan; Daniłko, Dariusz; Barral, Serge

    2015-04-15

    The effects of the inclination of the magnetic field with respect to the channel walls in a Hall effect thruster are numerically studied with the use of a one-dimensional quasi-neutral Particle-In-Cell model with guiding center approximation of electron motion along magnetic lines. Parametric studies suggest that the incidence angle strongly influences electron transport across the magnetic field. In ion-focusing magnetic topologies, electrons collide predominantly on the side of the magnetic flux tube closer to the anode, thus increasing the electron cross-field drift. The opposite effect is observed in ion-defocussing topology.

  5. Quantum Hall effect in HgTe quantum wells at nitrogen temperatures

    SciTech Connect (OSTI)

    Kozlov, D. A. Kvon, Z. D.; Mikhailov, N. N.; Dvoretskii, S. A.; Weishäupl, S.; Krupko, Y.; Portal, J.-C.

    2014-09-29

    We report on the observation of quantized Hall plateaus in a system of two-dimensional Dirac fermions, implemented in a 6.6 nm HgTe quantum well at magnetic fields up to 34 T at nitrogen temperatures. The activation energies determined from the temperature dependence of the longitudinal resistivity are found to be almost equal for the filling factors ν of 1 and 2. This indicates that the large values of the g-factor (about 30–40) remain unchanged at very strong magnetic fields.

  6. Optimal preselection and postselection in weak measurements for observing photonic spin Hall effect

    SciTech Connect (OSTI)

    Zhou, Xinxing; Li, Xing; Luo, Hailu Wen, Shuangchun

    2014-02-03

    Photonic spin Hall effect (SHE) holds great potential applications in precision metrology. How to obtain a high measurement precision is an important issue to detect the photonic SHE. In this Letter, we propose using optimal preselection and postselection in weak measurements to enhance the measurement precision. We find that the maximum weak value and pointer shift can be obtained with an optimal overlap of preselection and postselection states. These findings offer the possibility for improving the precision of weak measurements and thereby have possible applications for accurately characterizing the parameters of nanostructures.

  7. Domain wall motion driven by spin Hall effect—Tuning with in-plane magnetic anisotropy

    SciTech Connect (OSTI)

    Rushforth, A. W.

    2014-04-21

    This letter investigates the effects of in-plane magnetic anisotropy on the current induced motion of magnetic domain walls in systems with dominant perpendicular magnetic anisotropy, where accumulated spins from the spin Hall effect in an adjacent heavy metal layer are responsible for driving the domain wall motion. It is found that that the sign and magnitude of the domain wall velocity in the uniform flow regime can be tuned significantly by the in-plane magnetic anisotropy. These effects are sensitive to the ratio of the adiabatic and non-adiabatic spin transfer torque parameters and are robust in the presence of pinning and thermal fluctuations.

  8. Recent results and challenges in development of metallic Hall sensors for fusion reactors

    SciTech Connect (OSTI)

    ?uran, Ivan; Mulek, Radek; Kova?k, Karel; Sentkerestiov, Jana; Kohout, Michal

    2014-08-21

    Reliable and precise diagnostic of local magnetic field is crucial for successful operation of future thermonuclear fusion reactors based on magnetic confinement. Magnetic sensors at these devices will experience an extremely demanding operational environment with large radiation and thermal loads in combination with required long term, reliable, and service-free performance. Neither present day commercial nor laboratory measurement systems comply with these requirements. Metallic Hall sensors based on e.g. copper or bismuth could potentially satisfy these needs. We present the technology for manufacturing of such sensors and some initial results on characterization of their properties.

  9. Spin Hall magnetoresistance in CoFe2O4/Pt films

    SciTech Connect (OSTI)

    Wu, Hao; Qintong, Zhang; Caihua, Wan; Ali, Syed Shahbaz; Yuan, Zhonghui; You, Lu; Wang, Junling; Choi, Yongseong; Han, Xiufeng

    2015-05-13

    Pulse laser deposition and magnetron sputtering techniques have been employed to prepare MgO(001)//CoFe2O4/Pt samples. Cross section transmission electron microscope results prove that the CoFe2O4 film epitaxially grew along (001) direction. X-ray magnetic circular dichroism results show that magnetic proximity effect in this sample is negligible. Magnetoresistance (MR) properties confirm that spin Hall MR (SMR) dominates in this system. Spin Hall effect-induced anomalous Hall voltage was also observed in this sample. Lastly, these results not only demonstrate the universality of SMR effect but also demonstrate the utility in spintronics of CoFe2O4 as a new type of magnetic insulator.

  10. Gracie Hall

    Broader source: Energy.gov [DOE]

    Gracie is a student representative to the board for FY 2013-14. She is a senior at Oak Ridge High School, where she is a member of the National Honor Society, the Oak Ridge High School marching and...

  11. The Hall

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... The 11 chord polarimetry and interferometry data are routinely sampled at 1 MHz with the different frequency being aliased down to 250 kHz. This results in a 4 s time response ...

  12. Source and Extraction for Simultaneous Four-hall Beam Delivery System at CEBAF

    SciTech Connect (OSTI)

    Kazimi, Reza; Wang, Haipeng; Spata, Mike F.; Hansknecht, John C.

    2013-06-01

    A new design for simultaneous delivery of the electron beam to all four 12 GeV CEBAF experimental halls* requires a new 750 MHz RF separator system in the 5th pass extraction region, a 250 MHz repetition rate for its beams, and addition of a fourth laser at the photo-cathode gun. The proposed system works in tandem with the existing 500 MHz RF separators and beam repetition rate on the lower passes. The new 5th pass RF separators will have the same basic design but modified to run at 750 MHz. The change to the beam repetition rate will be at the photo-cathode gun through an innovative upgrade of the seed laser driver system using electro-optic modulators. The new laser system also allows addition of the fourth laser. The new RF separators, the new laser system and other hardware changes required to implement the Four-Hall operation delivery system will be discussed in this paper.

  13. Temperature-driven band inversion in Pb?.??Sn?.??Se: Optical and Hall-effect studies

    SciTech Connect (OSTI)

    Anand, Naween; Gu, Genda; Buvaev, Sanal; Hebard, A. F.; Tanner, D. B.; Chen, Zhiguo; Li, Zhiqiang; Choudhary, Kamal; Sinnott, S. B.; Martin, C.

    2014-12-23

    Optical and Hall-effect measurements have been performed on single crystals of Pb?.??Sn?.??Se, a IV-VI mixed chalcogenide. The temperature dependent (10300 K) reflectance was measured over 407000 cm? (5870 meV) with an extension to 15,500 cm? (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy optical spectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Density function theory calculation for the electronic band structure also make similar predictions.

  14. Temperature-driven band inversion in Pb?.??Sn?.??Se: Optical and Hall-effect studies

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anand, Naween; Gu, Genda; Buvaev, Sanal; Hebard, A. F.; Tanner, D. B.; Chen, Zhiguo; Li, Zhiqiang; Choudhary, Kamal; Sinnott, S. B.; Martin, C.

    2014-12-23

    Optical and Hall-effect measurements have been performed on single crystals of Pb?.??Sn?.??Se, a IV-VI mixed chalcogenide. The temperature dependent (10300 K) reflectance was measured over 407000 cm? (5870 meV) with an extension to 15,500 cm? (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy opticalmorespectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Density function theory calculation for the electronic band structure also make similar predictions.less

  15. Modulational instability and associated rogue structures of slow magnetosonic wave in Hall magnetohydrodynamic plasmas

    SciTech Connect (OSTI)

    Panwar, Anuraj; Ryu, Chang-Mo

    2014-06-15

    The modulational instability and associated rogue structures of a slow magnetosonic wave are investigated for a Hall magnetohydrodynamic plasma. Nonlinear Schrodinger equation is obtained by using the multiple scale method, which shows a modulationally unstable slow magnetosonic mode evolving into bright wavepackets. The dispersive effects induced by the Hall electron current increase with the increase in plasma β and become weaker as the angle of propagation increases. The growth rate of the modulational instability also increases with the increase in plasma β. The growth rate is greatest for the parallel propagation and drops to zero for perpendicular propagation. The envelope wavepacket of a slow magnetosonic is widened with less oscillations as plasma β increases. But the wavepacket becomes slightly narrower and more oscillatory as the angle of propagation increases. Further a non-stationary envelope solution of the Peregrine soliton is analyzed for rogue waves. The Peregrine soliton contracts temporally and expands spatially with increase in plasma β. However, the width of a slow magnetosonic Peregrine soliton decreases both temporally and spatially with increase of the propagation angle.

  16. Method for analyzing ExB probe spectra from Hall thruster plumes

    SciTech Connect (OSTI)

    Shastry, Rohit; Hofer, Richard R.; Reid, Bryan M.; Gallimore, Alec D.

    2009-06-15

    Various methods for accurately determining ion species' current fractions using ExB probes in Hall thruster plumes are investigated. The effects of peak broadening and charge exchange on the calculated values of current fractions are quantified in order to determine the importance of accounting for them in the analysis. It is shown that both peak broadening and charge exchange have a significant effect on the calculated current fractions over a variety of operating conditions, especially at operating pressures exceeding 10{sup -5} torr. However, these effects can be accounted for using a simple approximation for the velocity distribution function and a one-dimensional charge exchange correction model. In order to keep plume attenuation from charge exchange below 30%, it is recommended that pz{<=}2, where p is the measured facility pressure in units of 10{sup -5} torr and z is the distance from the thruster exit plane to the probe inlet in meters. The spatial variation of the current fractions in the plume of a Hall thruster and the error induced from taking a single-point measurement are also briefly discussed.

  17. Structure of intermediate shocks in collisionless anisotropic Hall-magnetohydrodynamics plasma models

    SciTech Connect (OSTI)

    Snchez-Arriaga, G.

    2013-10-15

    The existence of discontinuities within the double-adiabatic Hall-magnetohydrodynamics (MHD) model is discussed. These solutions are transitional layers where some of the plasma properties change from one equilibrium state to another. Under the assumption of traveling wave solutions with velocity C and propagation angle ? with respect to the ambient magnetic field, the Hall-MHD model reduces to a dynamical system and the waves are heteroclinic orbits joining two different fixed points. The analysis of the fixed points rules out the existence of rotational discontinuities. Simple considerations about the Hamiltonian nature of the system show that, unlike dissipative models, the intermediate shock waves are organized in branches in parameter space, i.e., they occur if a given relationship between ? and C is satisfied. Electron-polarized (ion-polarized) shock waves exhibit, in addition to a reversal of the magnetic field component tangential to the shock front, a maximum (minimum) of the magnetic field amplitude. The jumps of the magnetic field and the relative specific volume between the downstream and the upstream states as a function of the plasma properties are presented. The organization in parameter space of localized structures including in the model the influence of finite Larmor radius is discussed.

  18. Energy Efficiency Improvements to Wundar Hall, a Historic Building on the Concordia Campus, Milwaukee, Wisconsin

    SciTech Connect (OSTI)

    Karman, Nathan

    2012-11-29

    The Forest County Potawatomi Community (??FCPC? or ??Community?) implemented energy efficiency improvements to revitalize Wundar Hall, a 34,000 square foot (??SF?) building that was formerly used as a dormitory and is listed on the National Registry of Historic Places, into an office building. Wundar Hall is the first of many architecturally and historically significant buildings that the Community hopes to renovate at the former Concordia College campus, property on the near west side of Milwaukee that was taken into trust for the Community by the United States on July 10, 1990 (collectively, the ??Concordia Trust Property?). As part of this project, which was conducted with assistance from the Department of Energy??s Tribal Energy Program (??TEP?), the Community updated and/or replaced the building envelope, mechanical systems, the plumbing system, the electrical infrastructure, and building control systems. The project is expected to reduce the building??s natural gas consumption by 58% and the electricity consumption by 55%. In addition, the project was designed to act as a catalyst to further renovation of the Concordia Trust Property and the neighborhood. The City of Milwaukee has identified redevelopment of the Concordia Trust Property as a ??Catalytic Project? for revitalizing the near west side. The Tribe envisions a revitalized, mixed-use campus of community services, education, and economic development??providing services to the Indian community and jobs to the neighborhood.

  19. Resonant cavity mode dependence of anomalous and inverse spin Hall effect

    SciTech Connect (OSTI)

    Kim, Sang-Il; Seo, Min-Su; Park, Seung-young

    2014-05-07

    The direct current electric voltage induced by the Inverse Spin Hall Effect (ISHE) and Anomalous Hall Effect (AHE) was investigated in the TE{sub 011} and TE{sub 102} cavities. The ISHE and AHE components were distinguishable through the fitting of the voltage spectrum. The unwanted AHE was minimized by placing the DUT (Device Under Test) at the center of both the TE{sub 011} and TE{sub 102} cavities. The voltage of ISHE in the TE{sub 011} cavity was larger than that in the TE{sub 102} cavity due to the higher quality factor of the former. Despite optimized centering, AHE voltage from TE{sub 011} cavity was also higher. The reason was attributed to the E-field distribution inside the cavity. In the case of the TE{sub 011} cavity, the DUT was easily exposed to the E-field in all directions. Therefore, the parasitic AHE voltage in the TE{sub 102} cavity was less sensitive than that in the TE{sub 011} cavity to decentering problem.

  20. Beta (β) tungsten thin films: Structure, electron transport, and giant spin Hall effect

    SciTech Connect (OSTI)

    Hao, Qiang; Chen, Wenzhe; Xiao, Gang

    2015-05-04

    We use a simple magnetron sputtering process to fabricate beta (β) tungsten thin films, which are capable of generating giant spin Hall effect. As-deposited thin films are always in the metastable β-W phase from 3.0 to 26.7 nm. The β-W phase remains intact below a critical thickness of 22.1 nm even after magnetic thermal annealing at 280 °C, which is required to induce perpendicular magnetic anisotropy (PMA) in a layered structure of β-W/Co{sub 40}Fe{sub 40}B{sub 20}/MgO. Intensive annealing transforms the thicker films (>22.1 nm) into the stable α-W phase. We analyze the structure and grain size of both β- and α-W thin films. Electron transport in terms of resistivity and normal Hall effect is studied over a broad temperature range of 10 K to at least 300 K on all samples. Very low switching current densities are achieved in β-W/Co{sub 40}Fe{sub 40}B{sub 20}/MgO with PMA. These basic properties reveal useful behaviors in β-W thin films, making them technologically promising for spintronic magnetic random access memories and spin-logic devices.

  1. Temperature dependent van der Pauw-Hall measurements on sodium doped single crystalline cadmium telluride

    SciTech Connect (OSTI)

    Ahmad, Faisal R.

    2015-03-21

    In this report, results of the temperature dependent electrical conductivity measurements conducted on single crystalline cadmium telluride (CdTe), containing sodium (Na) impurities are presented and discussed. The electrical conductivity measurements were conducted using an apparatus that allowed the implementation of a standard van der Pauw-Hall effect technique through which the electrical resistivity, concentration of majority carriers, as well as the carrier mobility were determined for temperatures ranging between 24 K and 350 K. Over this temperature range, the electrical resistivity was observed to change by 7 orders of magnitude. Hall measurements showed that the hole concentration at 300 K was ∼3 × 10{sup 15 }cm{sup –3} and the hole mobility at the same temperature was ∼80 cm{sup 2}/V s. Measuring the concentration of holes as a function of the sample temperature enabled the estimation of the acceptor energy level with respect to the valence band maximum to be ∼60 meV. The same data also revealed the potential presence of a compensating donor level. Furthermore, the hole mobility was also analyzed over the entire temperature range and the data revealed that above 100 K, the carrier mobility was dominated by the scattering of holes from lattice vibrations.

  2. Comparison of two data acquisition and processing systems of Moller polarimeter in Hall A of Jefferson Lab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vereshchaka, Vadym V.; Glamazdin, Oleksandr V.; Pomatsalyuk, Roman I.

    2014-07-01

    Two data acquisition and processing systems are used simultaneously to measure electron beam polarization by Moller polarimeter in Hall A of Jefferson Lab (Newport News, VA, USA). The old system (since 1997) is fully functional, but is not repairable in case of malfunction (system modules arenot manufactured anymore). The new system (since 2010) based on flash-ADC is more accurate, but currently requires more detailed adjustment and further improvement. Description and specifications of two data acquisition and processing systems have been given. The results of polarization measurements during experiments conducted in Hall A from 2010 to 2012 are compared.

  3. Effect of the magnetic lenses on the electron current due to near wall conductivity in a Hall thruster

    SciTech Connect (OSTI)

    Wu Zhiwen; Liu Xiangyang; Wang Ningfei; Yu Daren

    2010-07-15

    The effect of magnetic lens on the electron current due to near wall conductivity (NWC) in a Hall thruster is studied. A Monte Carlo model is employed to simulate the effect of the large magnetic field incidence angle on the electron current. The simulation results show that the electron current due to NWC decreases in the case of large incidence. The simulation qualitatively agrees with the related experimental result. And the simulation also demonstrates that choosing the curvature angle of the magnetic field is also a key factor to design a Hall thruster with high operation performance.

  4. Comparison of two data acquisition and processing systems of Moller polarimeter in Hall A of Jefferson Lab

    SciTech Connect (OSTI)

    Vereshchaka, Vadym V.; Glamazdin, Oleksandr V.; Pomatsalyuk, Roman I.

    2014-07-01

    Two data acquisition and processing systems are used simultaneously to measure electron beam polarization by Moller polarimeter in Hall A of Jefferson Lab (Newport News, VA, USA). The old system (since 1997) is fully functional, but is not repairable in case of malfunction (system modules arenot manufactured anymore). The new system (since 2010) based on flash-ADC is more accurate, but currently requires more detailed adjustment and further improvement. Description and specifications of two data acquisition and processing systems have been given. The results of polarization measurements during experiments conducted in Hall A from 2010 to 2012 are compared.

  5. Tune In To Our Online Town Hall With Sec. Chu at 12:45PM EST | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy Tune In To Our Online Town Hall With Sec. Chu at 12:45PM EST Tune In To Our Online Town Hall With Sec. Chu at 12:45PM EST January 26, 2011 - 8:35am Addthis Ginny Simmons Ginny Simmons Former Managing Editor for Energy.gov, Office of Public Affairs During the State of the Union address last night, President Obama placed the national spotlight on clean energy, saying that "we need to out-innovate, out-educate, and out-build the rest of the world," and that we must invest in

  6. Robustness of fractional quantum Hall states with dipolar atoms in artificial gauge fields

    SciTech Connect (OSTI)

    Grass, T.; Baranov, M. A.; Lewenstein, M.

    2011-10-15

    The robustness of fractional quantum Hall states is measured as the energy gap separating the Laughlin ground state from excitations. Using thermodynamic approximations for the correlation functions of the Laughlin state and the quasihole state, we evaluate the gap in a two-dimensional system of dipolar atoms exposed to an artificial gauge field. For Abelian fields, our results agree well with the results of exact diagonalization for small systems but indicate that the large value of the gap predicted [Phys. Rev. Lett. 94, 070404 (2005)] was overestimated. However, we are able to show that the small gap found in the Abelian scenario dramatically increases if we turn to non-Abelian fields squeezing the Landau levels.

  7. Optimized electrode placement along the channel of a Hall thruster for ion focusing

    SciTech Connect (OSTI)

    Qing, Shaowei, E-mail: qshaowei@gmail.com [Power Engineering Institute, Chongqing University, Chongqing 400044 (China); E, Peng [Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Xia, Guangqing [State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024 (China); Tang, Ming-Chun [College of Communication Engineering, Chongqing University, Chongqing 400044 (China); Duan, Ping [School of Physics, Dalian Maritime University, Dalian 116026 (China)

    2014-01-21

    An optimal placement of the segmented electrode for increasing the lifetime of the Aton-type Hall thruster, i.e., reducing the plume divergence, is demonstrated using a 2D3V fully kinetic Particle-in-Cell method. Segmented electrodes, embedded near the ionization region of non-segmented case and biased above anode potential, lead to an increased separation between the ionization and acceleration regions and the formation of an efficient acceleration electric field configuration as potential lens. Due to this electrode placement, the sheath near the ceramic walls of the acceleration region is collapsed and an excellent ion beam focusing is demonstrated. The potential contour pockets around the electrodes and the sheath collapse phenomenon are also discussed.

  8. Position-Momentum Duality and Fractional Quantum Hall Effect in Chern Insulators

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Claassen, Martin; Lee, Ching-Hua; Thomale, Ronny; Qi, Xiao-Liang; Devereaux, Thomas P

    2015-06-11

    We develop a first quantization description of fractional Chern insulators that is the dual of the conventional fractional quantum Hall (FQH) problem, with the roles of position and momentum interchanged. In this picture, FQH states are described by anisotropic FQH liquids forming in momentum-space Landau levels in a fluctuating magnetic field. The fundamental quantum geometry of the problem emerges from the interplay of single-body and interaction metrics, both of which act as momentum-space duals of the geometrical picture of the anisotropic FQH effect. We then present a novel broad class of ideal Chern insulator lattice models that act as dualsmore » of the isotropic FQH effect. The interacting problem is well-captured by Haldane pseudopotentials and affords a detailed microscopic understanding of the interplay of interactions and non-trivial quantum geometry.« less

  9. D0 Silicon Upgrade: D-Zero Assembly Hall ODH Analysis

    SciTech Connect (OSTI)

    Rucinski, Russ; /Fermilab

    1997-03-12

    The ODH analysis presented here covers the high bay and assembly hall docking area of the for the D-Zero detector. It includes the STand Alone helium Refrigerator (STAR) in the building. It also includes the D-Zero detector and it's associated cryogenic and gas systems. An ODH analysis is presented which shows that the D-Zero assembly building high bay including the detector docking area is ODH class O. Probabilities, leak rates, and fatality factors are generated for all items that are sources of inert gas. The scope of analysis included the calorimeter and gas components on the detector, the helium refrigerator/liquifier components, and the future solenoid and visible light photon counter cryogenics that will be added to the D-Zero detector. The analysis demonstrates that the calorimeter and helium refrigerator systems pose no ODH hazard to personnel.

  10. X-ray K-edge analysis of drain lines in Wilhelm Hall, Ames Laboratory

    SciTech Connect (OSTI)

    Jensen, T.; Whitmore, C. |

    1999-01-05

    From August 12--27, 1998 X-ray K-edge measurements were made on drain lines in seven rooms in Wilhelm Hall, Ames Laboratory. The purpose of these measurements was to determine the extent of thorium (and other heavy metal) contamination inside these pipes. The K-edge method is a noninvasive inspection technique that can provide accurate quantification of heavy metal contamination interior to an object. Of the seven drain lines inspected, one was found to have no significant contamination, three showed significant thorium deposits, two showed mercury contamination, and one line was found to contain mercury, thorium and uranium. The K-edge measurements were found to be consistent with readings from hand-held survey meters, and provided much greater detail on the location and amount of heavy metal contamination.

  11. Position-Momentum Duality and Fractional Quantum Hall Effect in Chern Insulators

    SciTech Connect (OSTI)

    Claassen, Martin; Lee, Ching-Hua; Thomale, Ronny; Qi, Xiao-Liang; Devereaux, Thomas P

    2015-06-11

    We develop a first quantization description of fractional Chern insulators that is the dual of the conventional fractional quantum Hall (FQH) problem, with the roles of position and momentum interchanged. In this picture, FQH states are described by anisotropic FQH liquids forming in momentum-space Landau levels in a fluctuating magnetic field. The fundamental quantum geometry of the problem emerges from the interplay of single-body and interaction metrics, both of which act as momentum-space duals of the geometrical picture of the anisotropic FQH effect. We then present a novel broad class of ideal Chern insulator lattice models that act as duals of the isotropic FQH effect. The interacting problem is well-captured by Haldane pseudopotentials and affords a detailed microscopic understanding of the interplay of interactions and non-trivial quantum geometry.

  12. Hall magnetohydrodynamics simulations of end-shorting induced rotation in field-reversed configurations

    SciTech Connect (OSTI)

    Macnab, A. I. D.; Milroy, R. D.; Kim, C. C.; Sovinec, C. R.

    2007-09-15

    End-shorting of the open field lines that surround a field-reversed configuration (FRC) is believed to contribute to its observed rotation. In this study, nonlinear extended magnetohydrodynamics (MHD) simulations were performed that detail the end-shorting process and the resulting spin-up of the FRC. The tangential component of the electric field E{sub T} is set to zero at the axial boundaries in an extended MHD model that includes the Hall and {nabla}P{sub e} terms. This shorting of the electric field leads to the generation of toroidal fields on the open field lines, which apply a torque leading to a rotation of the ions on the open field lines. The FRC then gains angular momentum through a viscous transfer from the open field line region. In addition, it is shown that spin-up is still induced when insulating boundaries are assumed.

  13. Diffusion Compton profondement virtuelle dans le Hall A au Jefferson Laboratory

    SciTech Connect (OSTI)

    Carlos Munoz Camacho

    2005-12-01

    Generalized Parton Distributions (GPDs), introduced in the late 90s, provide a universal description of hadrons in terms of the underlying degrees of freedom of Quantum Chromodynamics: quarks and gluons. GPDs appear in a wide variety of hard exclusive reactions and the advent of high luminosity accelerator facilities has made the study of GPDs accessible to experiment. Deeply Virtual Compton Scattering (DVCS) is the golden process involving GPDs. The first dedicated DVCS experiment ran in the Hall A of Jefferson Lab in Fall 2004. An electromagnetic calorimeter and a plastic scintillator detector were constructed for this experiment, together with specific electronics and acquisition system. The experiment preparation, data taking and analysis are described in this document. Results on the absolute cross section difference for opposite beam helicities provide the first measurement of a linear combination of GPDs as a function of the momentum transfer to the nucleon.

  14. Record surface state mobility and quantum Hall effect in topological insulator thin films via interface engineering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Koirala, Nikesh; Han, Myung -Geun; Brahlek, Matthew; Salehi, Maryam; Wu, Liang; Dai, Jixia; Waugh, Justin; Nummy, Thomas; Moon, Jisoo; Zhu, Yimei; et al

    2015-11-19

    Material defects remain as the main bottleneck to the progress of topological insulators (TIs). In particular, efforts to achieve thin TI samples with dominant surface transport have always led to increased defects and degraded mobilities, thus making it difficult to probe the quantum regime of the topological surface states. Here, by utilizing a novel buffer layer scheme composed of an In2Se3/(Bi0.5In0.5)2Se3 heterostructure, we introduce a quantum generation of Bi2Se3 films with an order of magnitude enhanced mobilities than before. Furthermore, this scheme has led to the first observation of the quantum Hall effect in Bi2Se3.

  15. Exploration of deeply virtual Compton scattering on the neutron in the Hall A of Jefferson Laboratory

    SciTech Connect (OSTI)

    Malek Mazouz

    2006-12-08

    Generalized Parton Distributions (GPDs) are universal functions which provide a comprehensive description of hadron properties in terms of quarks and gluons. Deeply Virtual Compton Scattering (DVCS) is the simplest hard exclusive process involving GPDs. In particular, the DVCS on the neutron is mostly sensitive to E, the less constrained GPD, wich allows to access to the quark angular momentum. The first dedicated DVCS experiment on the neutron ran in the Hall A of Jefferson Lab in fall 2004. The high luminosity of the experiment and the resulting background rate recquired specific devices which are decribed in this document. The analysis methods and the experiment results, leading to preliminary constraints on the GPD E, are presented.

  16. Systems and methods for cylindrical hall thrusters with independently controllable ionization and acceleration stages

    DOE Patents [OSTI]

    Diamant, Kevin David; Raitses, Yevgeny; Fisch, Nathaniel Joseph

    2014-05-13

    Systems and methods may be provided for cylindrical Hall thrusters with independently controllable ionization and acceleration stages. The systems and methods may include a cylindrical channel having a center axial direction, a gas inlet for directing ionizable gas to an ionization section of the cylindrical channel, an ionization device that ionizes at least a portion of the ionizable gas within the ionization section to generate ionized gas, and an acceleration device distinct from the ionization device. The acceleration device may provide an axial electric field for an acceleration section of the cylindrical channel to accelerate the ionized gas through the acceleration section, where the axial electric field has an axial direction in relation to the center axial direction. The ionization section and the acceleration section of the cylindrical channel may be substantially non-overlapping.

  17. Commissioning and Testing the 1970's Era LASS Solenoid Magnet in JLab's Hall D

    SciTech Connect (OSTI)

    Ballard, Joshua T.; Biallas, George H.; Brown, G.; Butler, David E.; Carstens, Thomas J.; Chudakov, Eugene A.; Creel, Jonathan D.; Egiyan, Hovanes; Martin, F.; Qiang, Yi; Smith, Elton S.; Stevens, Mark A.; Spiegel, Scot L.; Whitlatch, Timothy E.; Wolin, Elliott J.; Ghoshal, Probir K.

    2015-06-01

    JLab refurbished and reconfigured the LASS1, 1.85m bore Solenoid and installed it as the principal analysis magnet for nuclear physics in the newly constructed, Hall D at Jefferson Lab. The magnet contains four superconducting coils within an iron yoke. The magnet was built in the early1970's at Stanford Linear Accelerator Center and used a second time at Los Alamos National Laboratory. The coils were extensively refurbished and individually tested by JLab. A new Cryogenic Distribution Box provides cryogens and their control valving, current distribution bus, and instrumentation pass-through. A repurposed CTI 2800 refrigerator system and new transfer line complete the system. We describe the re-configuration, the process and problems of re-commissioning the magnet and the results of testing the completed magnet.

  18. Detection of in-depth helical spin structures by planar Hall effect

    SciTech Connect (OSTI)

    Basaran, Ali C. Guénon, S.; Schuller, Ivan K.; Morales, R.

    2015-06-22

    We developed a method to determine the magnetic helicity and to study reversal mechanisms in exchange biased nanostructures using Planar Hall Effect (PHE). As a test case, we use an in-depth helical spin configuration that occurs during magnetization reversal in exchange coupled Ni/FeF{sub 2} heterostructures. We show the way to induce and determine the sign of the helicity from PHE measurements on a lithographically patterned cross. The helicity sign can be controlled by the angle between the externally applied magnetic field and a well-defined unidirectional anisotropy axis. Furthermore, the PHE signal reveals complex reversal features due to small deviations of the local unidirectional anisotropy axes from the crystallographic easy axis. The simulations using an incomplete domain wall model are in excellent agreement with the experimental data. These studies show that helical spin formations in nanomagnetic systems can be studied using laboratory-based magnetotransport.

  19. Extrinsic anomalous Hall effect in epitaxial Mn{sub 4}N films

    SciTech Connect (OSTI)

    Meng, M.; Wu, S. X. Ren, L. Z.; Zhou, W. Q.; Wang, Y. J.; Wang, G. L.; Li, S. W.

    2015-01-19

    Anomalous Hall effect (AHE) in ferrimagnetic Mn{sub 4}N epitaxial films grown by molecular-beam epitaxy is investigated. The longitudinal conductivity σ{sub xx} is within the superclean regime, indicating Mn{sub 4}N is a highly conducting material. We further demonstrate that the AHE signal in 40-nm-thick films is mainly due to the extrinsic contributions based on the analysis fitted by ρ{sub AH}=a′ρ{sub xx0}+bρ{sub xx}{sup 2} and σ{sub AH}∝σ{sub xx}. Our study not only provide a strategy for further theoretical work on antiperovskite manganese nitrides but also shed promising light on utilizing their extrinsic AHE to fabricate spintronic devices.

  20. Observation of inverse spin Hall effect in ferromagnetic FePt alloys using spin Seebeck effect

    SciTech Connect (OSTI)

    Seki, Takeshi Takanashi, Koki; Uchida, Ken-ichi; Kikkawa, Takashi; Qiu, Zhiyong; Saitoh, Eiji

    2015-08-31

    We experimentally observed the inverse spin Hall effect (ISHE) of ferromagnetic FePt alloys. Spin Seebeck effect due to the temperature gradient generated the spin current (J{sub s}) in the FePt|Y{sub 3}Fe{sub 5}O{sub 12} (YIG) structure, and J{sub s} was injected from YIG to FePt and converted to the charge current through ISHE of FePt. The significant difference in magnetization switching fields for FePt and YIG led to the clear separation of the voltage of ISHE from that of anomalous Nernst effect in FePt. We also investigated the effect of ordering of FePt crystal structure on the magnitude of ISHE voltage in FePt.

  1. Design and Implementation of a Hall Effect Sensor Array Applied to Recycling Hard Drive Magnets

    SciTech Connect (OSTI)

    Kisner, Roger; Lenarduzzi, Roberto; Killough, Stephen M; McIntyre, Timothy J

    2015-01-01

    Rare earths are an important resource for many electronic components and technologies. Examples abound including Neodymium magnets used in mobile devices and computer hard drives (HDDs), and a variety of renewable energy technologies (e.g., wind turbines). Approximately 21,000 metric tons of Neodymium is processed annually with less than 1% being recycled. An economic system to assist in the recycling of magnet material from post-consumer goods, such as Neodymium Iron Boron magnets commonly found in hard drives is presented. A central component of this recycling measurement system uses an array of 128 Hall Effect sensors arranged in two columns to detect the magnetic flux lines orthogonal to the HDD. Results of using the system to scan planar shaped objects such as hard drives to identify and spatially locate rare-earth magnets for removal and recycling from HDDs are presented. Applications of the sensor array in other identification and localization of magnetic components and assemblies will be presented.

  2. Record surface state mobility and quantum Hall effect in topological insulator thin films via interface engineering

    SciTech Connect (OSTI)

    Koirala, Nikesh; Han, Myung -Geun; Brahlek, Matthew; Salehi, Maryam; Wu, Liang; Dai, Jixia; Waugh, Justin; Nummy, Thomas; Moon, Jisoo; Zhu, Yimei; Dessau, Daniel; Wu, Weida; Armitage, N. Peter; Oh, Seongshik

    2015-11-19

    Material defects remain as the main bottleneck to the progress of topological insulators (TIs). In particular, efforts to achieve thin TI samples with dominant surface transport have always led to increased defects and degraded mobilities, thus making it difficult to probe the quantum regime of the topological surface states. Here, by utilizing a novel buffer layer scheme composed of an In2Se3/(Bi0.5In0.5)2Se3 heterostructure, we introduce a quantum generation of Bi2Se3 films with an order of magnitude enhanced mobilities than before. Furthermore, this scheme has led to the first observation of the quantum Hall effect in Bi2Se3.

  3. Non Invasive estimation of aluminum concentration in Hall-Heroult reduction cells

    SciTech Connect (OSTI)

    David Bell

    2004-03-01

    The present best practice for the preparation of primary aluminum is by electrolysis of alumina in the traditional Hall-Heroult reduction cell. The process conditions in the electrolyte of this cell required for the reduction to proceed are sufficiently harsh to have precluded the implementation of in situ sensing of the electrolyte composition, specifically the concentration of the ionized alumina. This report reveals the theoretical basis for a non-invasive method for estimation of the ionized alumina concentration which does not require the use of any sensor in direct contact with the cell electrolyte. The proposed method can in principle be applied with equal efficacy to the so-called drained cathode cell designs and to cells having any anode composition, because only knowledge of the electrolyte conduction behavior is required a priori. For an operating cell, the proposed method requires only readily available electrical measurements and the facilities to process the acquired signals. The proposed method rests on the ability to identify certain characteristics of the transients in the reduction cell terminal voltages caused by the quasiperiodic introduction of alumina. It will be shown that these voltage transients manifest measurable properties, in a statistical sense, that should permit estimation of the ionized alumina concentration with a delay of one alumina feed cycle. The next logical step following the present work, consistent with the Aluminum Technology Roadmap [1], is to experimentally verify the predictions made here; no doubt practical refinements to the proposed approach will evolve during the course of experimentation. Successful verification of the proposed estimation method will permit the design of reduction cell control algorithms based directly on the mass balance of alumina in the electrolyte. This report assumes that the reader understands certain basic concepts important to the operation of electrolytic cells, and the Hall-Heroult cell

  4. Analysis of the spin Hall effect in CuIr alloys: Combined approach of density functional theory and Hartree-Fock approximation

    SciTech Connect (OSTI)

    Xu, Zhuo Gu, Bo; Mori, Michiyasu; Maekawa, Sadamichi; Ziman, Timothy

    2015-05-07

    We analyze the spin Hall effect in CuIr alloys in theory by the combined approach of the density functional theory (DFT) and Hartree-Fock (HF) approximation. The spin Hall angle (SHA) is obtained to be negative without the local correlation effects. After including the local correlation effects of the 5d orbitals of Ir impurities, the SHA becomes positive with realistic correlation parameters and consistent with experiment [Niimi et al., Phys. Rev. Lett. 106, 126601 (2011)]. Moreover, our analysis shows that the DFT + HF approach is a convenient and general method to study the influence of local correlation effects on the spin Hall effect.

  5. Temperature scaling in the quantum-Hall-effect regime in a HgTe quantum well with an inverted energy spectrum

    SciTech Connect (OSTI)

    Arapov, Yu. G.; Gudina, S. V.; Neverov, V. N.; Podgornykh, S. M.; Popov, M. R. Harus, G. I.; Shelushinina, N. G.; Yakunin, M. V.; Mikhailov, N. N.; Dvoretsky, S. A.

    2015-12-15

    The longitudinal and Hall magnetoresistances of HgTe/HgCdTe heterostructures with an inverted energy spectrum (the HgTe quantum well width is d = 20.3 nm) are measured in the quantum-Hall-effect regime at T = 2–50 K in magnetic fields up to B = 9 T. Analysis of the temperature dependences of conductivity in the transition region between the first and second plateaus of the quantum Hall effect shows the feasibility of the scaling regime for a plateau–plateau quantum phase transition in 2D-structures on the basis of mercury telluride.

  6. The spin Hall angle and spin diffusion length of Pd measured by spin pumping and microwave photoresistance

    SciTech Connect (OSTI)

    Tao, X. D.; Feng, Z.; Miao, B. F.; Sun, L.; You, B.; Wu, D.; Du, J.; Zhang, W.; Ding, H. F., E-mail: hfding@nju.edu.cn [Department of Physics, National Laboratory of Solid State Microstructures, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)

    2014-05-07

    We present the experimental study of the spin Hall angle (SHA) and spin diffusion length of Pd with the spin pumping and microwave photoresistance effects. The Py/Pd bilayer stripes are excited with an out-of-plane microwave magnetic field. The pure spin current is thus pumped and transforms into charge current via the inverse spin Hall effect (ISHE) in Pd layer, yielding an ISHE voltage. The ISHE voltage can be distinguished from the unwanted signal caused by the anisotropic magnetoresistance according to their different symmetries. Together with Pd thickness dependent measurements of in and out-of-plane precessing angles and effective spin mixing conductance, the SHA and spin-diffusion length of Pd are quantified as 0.0056??0.0007 and 7.3??0.7?nm, respectively.

  7. Analytical and computational study of the ideal full two-fluid plasma model and asymptotic approximations for Hall-magnetohydrodynamics

    SciTech Connect (OSTI)

    Srinivasan, B.; Shumlak, U.

    2011-09-15

    The 5-moment two-fluid plasma model uses Euler equations to describe the ion and electron fluids and Maxwell's equations to describe the electric and magnetic fields. Two-fluid physics becomes significant when the characteristic spatial scales are on the order of the ion skin depth and characteristic time scales are on the order of the ion cyclotron period. The full two-fluid plasma model has disparate characteristic speeds ranging from the ion and electron speeds of sound to the speed of light. Two asymptotic approximations are applied to the full two-fluid plasma to arrive at the Hall-MHD model, namely negligible electron inertia and infinite speed of light. The full two-fluid plasma model and the Hall-MHD model are studied for applications to an electromagnetic plasma shock, geospace environmental modeling (GEM challenge) magnetic reconnection, an axisymmetric Z-pinch, and an axisymmetric field reversed configuration (FRC).

  8. First e-/Photon Commissioning Results for the GlueX Experiment/Hall D at CEBAF

    SciTech Connect (OSTI)

    McCaughan, Michael D.; Satogata, Todd J.; Roblin, Yves R.; Benesch, Jay F.

    2015-09-01

    Experimental Hall D, with flagship experiment GlueX, was constructed as part of the 12 GeV CEBAF upgrade. A new magnetically extracted electron beam line was installed to support this hall. Bremsstrahlung photons from retractable radiators, are delivered to the experiment through a series of collimators following a long drift to allow for beam convergence. Coherent Bremsstrahlung generated by interaction with a diamond radiator will achieve a nominal 40% linear polarization and photon energies between 8.5 and 9 GeV from 12.1 GeV electrons, which are then tagged or diverted to a medium power 60kW electron dump. The expected photon flux is 107-108 Hz. This paper discusses the experimental line design, commissioning experience gained since first beam in spring 2014, and the present results of beam commissioning by the experiment.

  9. Intrinsic quantum anomalous Hall effect in the kagome lattice Cs2LiMn3F12

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Gang; Lian, Biao; Zhang, Shou -Cheng

    2015-10-27

    In a kagome lattice, the time reversal symmetry can be broken by a staggered magnetic flux emerging from ferromagnetic ordering and intrinsic spin-orbit coupling, leading to several well-separated nontrivial Chern bands and intrinsic quantum anomalous Hall effect. Based on this idea and ab initio calculations, we propose the realization of the intrinsic quantum anomalous Hall effect in the single layer Cs2Mn3F12 kagome lattice and on the (001) surface of a Cs2LiMn3F12 single crystal by modifying the carrier coverage on it, where the band gap is around 20 meV. Furthermore, a simplified tight binding model based on the in-plane ddσ antibondingmore » states is constructed to understand the topological band structures of the system.« less

  10. Quantized spin waves in single Co/Pt dots detected by anomalous Hall effect based ferromagnetic resonance

    SciTech Connect (OSTI)

    Kikuchi, N. Furuta, M.; Okamoto, S.; Kitakami, O.; Shimatsu, T.

    2014-12-15

    Anomalous Hall effect (AHE) based ferromagnetic resonance (FMR) measurements were carried out on perpendicularly magnetized Co/Pt multilayer single dots of 0.4–3 μm in diameter. The resonance behavior was measured by detecting the decrease of perpendicular magnetization component due to magnetization precession. Resonance behavior was observed as a clear decrease of Hall voltages, and the obtained resonance fields were consistent with the results of vector-network-analyzer FMR. Spin-waves with cylindrical symmetry became significant by decreasing the dot diameter, and quantized multiple resonances were observed in the dot of 0.4 μm in diameter. The AHE based FMR proposed here is a powerful method to approach magnetization dynamics including spin waves and non-linear behavior excited in a finite nanostructure.

  11. Metallic transport and large anomalous Hall effect at room temperature in ferrimagnetic Mn{sub 4}N epitaxial thin film

    SciTech Connect (OSTI)

    Shen, Xi; Shigematsu, Kei; Chikamatsu, Akira Fukumura, Tomoteru; Hirose, Yasushi; Hasegawa, Tetsuya

    2014-08-18

    We report the electrical transport properties of ferrimagnetic Mn{sub 4}N (001) epitaxial thin films grown by pulsed laser deposition on MgO (001) substrates. The Mn{sub 4}N thin films were tetragonally distorted with a ratio of out-of-plane to in-plane lattice constants of 0.987 and showed perpendicular magnetic anisotropy with an effective magnetic anisotropy constant of 0.16 MJ/m{sup 3}, which is comparable with that of a recently reported molecular-beam-epitaxy-grown film. The thin films exhibited metallic transport with a room temperature resistivity of 125 μΩ cm in addition to a large anomalous Hall effect with a Hall angle tangent of 0.023.

  12. Direct observation of a resolvable spin separation in the spin Hall effect of light at an air-glass interface

    SciTech Connect (OSTI)

    Ren, Jin-Li; Wang, Bo; Xiao, Yun-Feng; Gong, Qihuang; Li, Yan

    2015-09-14

    We theoretically and experimentally demonstrate that it is possible to directly observe the resolvable spin separation in the spin Hall effect of light at an air-glass interface by choosing optimal parameters. When a P-polarized light with a beam waist of 10 μm is incident around Brewster's angle, the two spin components of the reflected beam can be completely separated by eliminating the influence of the in-plane wavevector spread. This not only obviously reveals the strong impacts of the polarization state, the incident angle, the beam waist, and the in-plane wavevector spread, but also intuitively visualizes the observation of the spin Hall effect of light.

  13. Planar Hall effect in Y{sub 3}Fe{sub 5}O{sub 12}/IrMn films

    SciTech Connect (OSTI)

    Zhang, X. Zou, L. K.

    2014-12-29

    The planar Hall effect of IrMn on an yttrium iron garnet (YIG = Y{sub 3}Fe{sub 5}O{sub 12}) was measured in the magnetic field rotating in the film plane. The magnetic field angular dependence of planar Hall resistance (PHR) was observed in YIG/IrMn bilayer at different temperatures, while the Gd{sub 3}Ga{sub 5}O{sub 12}/IrMn film shows constant PHR for different magnetic field angles at both 10 K and 300 K. This provides evidence that IrMn has interfacial spins which can be led by ferrimagnetic layer in YIG/IrMn structure. A hysteresis can be observed in PHR-magnetic field angle loop of YIG/IrMn film at 10 K, indicative of the irreversible switching of IrMn interfacial spins at low temperature.

  14. Spin Hall switching of the magnetization in Ta/TbFeCo structures with bulk perpendicular anisotropy

    SciTech Connect (OSTI)

    Zhao, Zhengyang; Jamali, Mahdi; Smith, Angeline K.; Wang, Jian-Ping

    2015-03-30

    Spin-orbit torques are studied in Ta/TbFeCo/MgO patterned structures, where the ferrimagnetic material TbFeCo provides a strong bulk perpendicular magnetic anisotropy (bulk-PMA) independent of the interfaces. The current-induced magnetization switching in TbFeCo is investigated in the presence of a perpendicular, longitudinal, or transverse field. An unexpected partial-switching phenomenon is observed in the presence of a transverse field unique to our bulk-PMA material. It is found that the anti-damping torque related with spin Hall effect is very strong, and a spin Hall angle is determined to be 0.12. The field-like torque related with Rashba effect is unobservable, suggesting that the interface play a significant role in Rashba-like torque.

  15. Quantum valley Hall states and topological transitions in Pt(Ni, Pd)-decorated silicene: A first-principles study

    SciTech Connect (OSTI)

    Zhao, Bao; Zhang, Jiayong; Wang, Yicheng; Yang, Zhongqin

    2014-12-28

    The electronic states and topological behaviors of Pt(Ni, Pd)-decorated silicene are investigated by using an ab-initio method. All the three kinds of the adatoms prefer hollow sites of the silicene, guaranteeing the Dirac cones unbroken. The Pt(Ni, Pd)-decorated silicene systems all present quantum valley Hall (QVH) states with the gap opened exactly at the Fermi level. The gaps of the QVH states can be increased substantially by applying a positive electric field. Very fascinating phase transitions from QVH to quantum spin Hall (QSH) and then to QVH again are achieved in the Pt/Ni-decorated silicene when a negative electric field is applied. The QSH state in the Pd case with a negative electric field is, however, quenched because of relatively larger Rashba spin-orbit coupling (SOC) than the intrinsic SOC in the system. Our findings may be useful for the applications of silicene-based devices in valleytronics and spintronics.

  16. Influence of Mn concentration on magnetic topological insulator MnxBi2−xTe3 thin-film Hall-effect sensor

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ni, Y.; Zhang, Z.; Nlebedim, I. C.; Hadimani, R. L.; Jiles, D. C.

    2015-06-11

    Hall-effect (HE) sensors based on high-quality Mn-doped Bi2Te3 topological insulator (TI) thin films have been systematically studied in this paper. Improvement of Hall sensitivity is found after doping the magnetic element Mn into Bi2Te3. The sensors with low Mn concentrations, MnxBi2-xTe3, x = 0.01 and 0.08 show the linear behavior of Hall resistance with sensitivity about 5 Ω/T. And their Hall sensitivity shows weak dependence on temperature. For sensors with high Mn concentration (x = 0.23), the Hall resistance with respect to magnetic field shows a hysteretic behavior. Moreover, its sensitivity shows almost eight times as high as that ofmore » the HE sensors with low Mn concentration. The highest sensitivity can reach 43 Ω/T at very low magnetic field. This increase of Hall sensitivity is caused by the occurrence of anomalous HE (AHE) after ferromagnetic phase transition. Our work indicates that the magnetic-element-doped TIs with AHE are good candidates for HE sensors.« less

  17. Influence of Mn concentration on magnetic topological insulator MnxBi2−xTe3 thin-film Hall-effect sensor

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ni, Y.; Zhang, Z.; Nlebedim, I. C.; Hadimani, R. L.; Jiles, D. C.

    2015-06-11

    Hall-effect (HE) sensors based on high-quality Mn-doped Bi2Te3 topological insulator (TI) thin films have been systematically studied in this paper. Improvement of Hall sensitivity is found after doping the magnetic element Mn into Bi2Te3. The sensors with low Mn concentrations, MnxBi2-xTe3, x = 0.01 and 0.08 show the linear behavior of Hall resistance with sensitivity about 5 Ω/T. And their Hall sensitivity shows weak dependence on temperature. For sensors with high Mn concentration (x = 0.23), the Hall resistance with respect to magnetic field shows a hysteretic behavior. Moreover, its sensitivity shows almost eight times as high as that ofmore »the HE sensors with low Mn concentration. The highest sensitivity can reach 43 Ω/T at very low magnetic field. This increase of Hall sensitivity is caused by the occurrence of anomalous HE (AHE) after ferromagnetic phase transition. Our work indicates that the magnetic-element-doped TIs with AHE are good candidates for HE sensors.« less

  18. Isotropic Hall effect and ''freeze-in'' of carriers in the InGaAs self-assembled quantum wires

    SciTech Connect (OSTI)

    Kunets, Vas. P.; Prosandeev, S.; Mazur, Yu. I.; Ware, M. E.; Teodoro, M. D.; Dorogan, V. G.; Lytvyn, P. M.; Salamo, G. J.

    2011-10-15

    Using molecular beam epitaxy, we prepared an anisotropic media consisting of InGaAs quantum wires epitaxially grown on GaAs (311)A. Anisotropy is observed in the lateral conductivity and photoluminescence polarization. However, an isotropic Hall effect is observed in the same samples. We show that the Hall effect in this anisotropic heterostructure remains isotropic regardless of the change of the doping in GaAs barriers and regardless of the InGaAs coverage, whereas the conductivity anisotropy experiences a strong change under these actions. In addition, we observed an anomalous increase in carrier density, ''freeze-in,'' at low temperatures. In order to explain this, we generalized the theory of Look [D. C. Look, Phys. Rev B 42, 3578 (1990)] by considering the low field magneto-transport in anisotropic media. This theory confirms that the Hall constant remains isotropic in anisotropic semiconductor heterostructures, agreeing with our experiment and explains the anomalous behavior of carriers as a result of multi-band conductivity.

  19. Electroproduction de pions neutres dans le Hall A au Jefferson Laboratory

    SciTech Connect (OSTI)

    Eric Fuchey

    2010-06-01

    The past decade has seen a strong evolution of the study of the hadron structure through exclusive processes, allowing to access to a more complete description of this structure. Exclusive processes include DVCS (Deeply Virtual Compton Scattering) as well as hard exclusive meson production. This document is particularly focussed on the latter, and more particularly on exclusive neutral pion production. In this thesis is described the analysis of triple coincidence events H(e, e'{gamma}{gamma})X, which were a consequent by-product of the DVCS experiment which occured during Fall 2004 at Jefferson Lab Hall A, to extract the ep {yields} ep{pi}{sup 0} cross section. This cross section has been measured at two values of four-momentum transfer Q{sup 2} = 1.9 GeV{sup 2} and Q{sup 2} = 2.3 GeV{sup 2}. The statistical precision for these measurements is achieved at better than 5 %. The kinematic range allows to study the evolution of the extracted cross section as a function of Q{sup 2} and W. Results are be confronted with Regge inspired calculations and Generalized (GPD) predictions. An intepretation of our data within the framework of semi-inclusive deep inelastic scattering is also discussed.

  20. Magnetic modulation doping in topological insulators toward higher-temperature quantum anomalous Hall effect

    SciTech Connect (OSTI)

    Mogi, M. Yoshimi, R.; Yasuda, K.; Kozuka, Y.; Tsukazaki, A.; Takahashi, K. S.; Kawasaki, M.; Tokura, Y.

    2015-11-02

    Quantum anomalous Hall effect (QAHE), which generates dissipation-less edge current without external magnetic field, is observed in magnetic-ion doped topological insulators (TIs) such as Cr- and V-doped (Bi,Sb){sub 2}Te{sub 3}. The QAHE emerges when the Fermi level is inside the magnetically induced gap around the original Dirac point of the TI surface state. Although the size of gap is reported to be about 50 meV, the observable temperature of QAHE has been limited below 300 mK. We attempt magnetic-Cr modulation doping into topological insulator (Bi,Sb){sub 2}Te{sub 3} films to increase the observable temperature of QAHE. By introducing the rich-Cr-doped thin (1 nm) layers at the vicinity of both the surfaces based on non-Cr-doped (Bi,Sb){sub 2}Te{sub 3} films, we have succeeded in observing the QAHE up to 2 K. The improvement in the observable temperature achieved by this modulation-doping appears to be originating from the suppression of the disorder in the surface state interacting with the rich magnetic moments. Such a superlattice designing of the stabilized QAHE may pave a way to dissipation-less electronics based on the higher-temperature and zero magnetic-field quantum conduction.

  1. Large anomalous Hall effect in ferromagnetic insulator-topological insulator heterostructures

    SciTech Connect (OSTI)

    Alegria, L. D.; Petta, J. R.; Ji, H.; Cava, R. J.; Yao, N.; Clarke, J. J.

    2014-08-04

    We demonstrate the van der Waals epitaxy of the topological insulator compound Bi{sub 2}Te{sub 3} on the ferromagnetic insulator Cr{sub 2}Ge{sub 2}Te{sub 6}. The layers are oriented with (001)Bi{sub 2}Te{sub 3}||(001)Cr{sub 2}Ge{sub 2}Te{sub 6} and (110)Bi{sub 2}Te{sub 3}||(100)Cr{sub 2}Ge{sub 2}Te{sub 6}. Cross-sectional transmission electron microscopy indicates the formation of a sharp interface. At low temperatures, bilayers consisting of Bi{sub 2}Te{sub 3} on Cr{sub 2}Ge{sub 2}Te{sub 6} exhibit a large anomalous Hall effect (AHE). Tilted field studies of the AHE indicate that the easy axis lies along the c-axis of the heterostructure, consistent with magnetization measurements in bulk Cr{sub 2}Ge{sub 2}Te{sub 6}. The 61 K Curie temperature of Cr{sub 2}Ge{sub 2}Te{sub 6} and the use of near-stoichiometric materials may lead to the development of spintronic devices based on the AHE.

  2. Beam Position Reconstruction for the g2p Experiment in Hall A at Jefferson Lab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhu, Pengjia; Allada, Kalyan; Allison, Trent; Badman, Toby; Camsonne, Alexandre; Chen, Jian-ping; Cummings, Melissa; Gu, Chao; Huang, Min; Liu, Jie; et al

    2015-11-03

    Beam-line equipment was upgraded for experiment E08-027 (g2p) in Hall A at Jefferson Lab. Two beam position monitors (BPMs) were necessary to measure the beam position and angle at the target. A new BPM receiver was designed and built to handle the low beam currents (50-100 nA) used for this experiment. Two new super-harps were installed for calibrating the BPMs. In addition to the existing fast raster system, a slow raster system was installed. We found that before and during the experiment, these new devices were tested and debugged, and their performance was also evaluated. In order to achieve themore » required accuracy (1-2 mm in position and 1-2 mrad in angle at the target location), the data of the BPMs and harps were carefully analyzed, as well as reconstructing the beam position and angle event by event at the target location. Finally, the calculated beam position will be used in the data analysis to accurately determine the kinematics for each event.« less

  3. Beam Position Reconstruction for the g2p Experiment in Hall A at Jefferson Lab

    SciTech Connect (OSTI)

    Zhu, Pengjia; Allada, Kalyan; Allison, Trent; Badman, Toby; Camsonne, Alexandre; Chen, Jian-ping; Cummings, Melissa; Gu, Chao; Huang, Min; Liu, Jie; Musson, John; Slifer, Karl; Sulkosky, Vincent; Ye, Yunxiu; Zhang, Jixie; Zielinski, Ryan

    2015-11-03

    Beam-line equipment was upgraded for experiment E08-027 (g2p) in Hall A at Jefferson Lab. Two beam position monitors (BPMs) were necessary to measure the beam position and angle at the target. A new BPM receiver was designed and built to handle the low beam currents (50-100 nA) used for this experiment. Two new super-harps were installed for calibrating the BPMs. In addition to the existing fast raster system, a slow raster system was installed. We found that before and during the experiment, these new devices were tested and debugged, and their performance was also evaluated. In order to achieve the required accuracy (1-2 mm in position and 1-2 mrad in angle at the target location), the data of the BPMs and harps were carefully analyzed, as well as reconstructing the beam position and angle event by event at the target location. Finally, the calculated beam position will be used in the data analysis to accurately determine the kinematics for each event.

  4. Low frequency azimuthal stability of the ionization region of the Hall thruster discharge. I. Local analysis

    SciTech Connect (OSTI)

    Escobar, D.; Ahedo, E.

    2014-04-15

    Results based on a local linear stability analysis of the Hall thruster discharge are presented. A one-dimensional azimuthal framework is used including three species: neutrals, singly charged ions, and electrons. A simplified linear model is developed with the aim of deriving analytical expressions to characterize the stability of the ionization region. The results from the local analysis presented here indicate the existence of an instability that gives rise to an azimuthal oscillation in the +E??B direction with a long wavelength. According to the model, the instability seems to appear only in regions where the ionization and the electric field make it possible to have positive gradients of plasma density and ion velocity at the same time. A more complex model is also solved numerically to validate the analytical results. Additionally, parametric variations are carried out with respect to the main parameters of the model to identify the trends of the instability. As the temperature increases and the neutral-to-plasma density ratio decreases, the growth rate of the instability decreases down to a limit where azimuthal perturbations are no longer unstable.

  5. HALL EFFECT CONTROLLED GAS DYNAMICS IN PROTOPLANETARY DISKS. II. FULL 3D SIMULATIONS TOWARD THE OUTER DISK

    SciTech Connect (OSTI)

    Bai, Xue-Ning

    2015-01-10

    We perform three-dimensional stratified shearing-box magnetohydrodynamic (MHD) simulations on the gas dynamics of protoplanetary disks with a net vertical magnetic flux of B {sub z0}. All three nonideal MHD effects, Ohmic resistivity, the Hall effect, and ambipolar diffusion, are included in a self-consistent manner based on equilibrium chemistry. We focus on regions toward outer disk radii, from 5 to 60 AU, where Ohmic resistivity tends to become negligible, ambipolar diffusion dominates over an extended region across the disk height, and the Hall effect largely controls the dynamics near the disk midplane. We find that at around R = 5 AU the system launches a laminar or weakly turbulent magnetocentrifugal wind when the net vertical field B {sub z0} is not too weak. Moreover, the wind is able to achieve and maintain a configuration with reflection symmetry at the disk midplane. The case with anti-aligned field polarity (Ω⋅B{sub z0}<0) is more susceptible to the magnetorotational instability (MRI) when B {sub z0} decreases, leading to an outflow oscillating in radial directions and very inefficient angular momentum transport. At the outer disk around and beyond R = 30 AU, the system shows vigorous MRI turbulence in the surface layer due to far-UV ionization, which efficiently drives disk accretion. The Hall effect affects the stability of the midplane region to the MRI, leading to strong/weak Maxwell stress for aligned/anti-aligned field polarities. Nevertheless, the midplane region is only very weakly turbulent in both cases. Overall, the basic picture is analogous to the conventional layered accretion scenario applied to the outer disk. In addition, we find that the vertical magnetic flux is strongly concentrated into thin, azimuthally extended shells in most of our simulations beyond 15 AU, leading to enhanced radial density variations know as zonal flows. Theoretical implications and observational consequences are briefly discussed.

  6. Radiation and ionization energy loss simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab

    SciTech Connect (OSTI)

    Yan, Xin -Hu; Ye, Yun -Xiu; Chen, Jian -Ping; Lu, Hai -Jiang; Zhu, Peng -Jia; Jiang, Feng -Jian

    2015-07-17

    The radiation and ionization energy loss are presented for single arm Monte Carlo simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab. Radiation and ionization energy loss are discussed for $^{12}C$ elastic scattering simulation. The relative momentum ratio $\\frac{\\Delta p}{p}$ and $^{12}C$ elastic cross section are compared without and with radiation energy loss and a reasonable shape is obtained by the simulation. The total energy loss distribution is obtained, showing a Landau shape for $^{12}C$ elastic scattering. This simulation work will give good support for radiation correction analysis of the GDH sum rule experiment.

  7. Radiation and ionization energy loss simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yan, Xin -Hu; Ye, Yun -Xiu; Chen, Jian -Ping; Lu, Hai -Jiang; Zhu, Peng -Jia; Jiang, Feng -Jian

    2015-07-17

    The radiation and ionization energy loss are presented for single arm Monte Carlo simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab. Radiation and ionization energy loss are discussed formore » $$^{12}C$$ elastic scattering simulation. The relative momentum ratio $$\\frac{\\Delta p}{p}$$ and $$^{12}C$$ elastic cross section are compared without and with radiation energy loss and a reasonable shape is obtained by the simulation. The total energy loss distribution is obtained, showing a Landau shape for $$^{12}C$$ elastic scattering. This simulation work will give good support for radiation correction analysis of the GDH sum rule experiment.« less

  8. Grain-boundary strengthening in nanocrystalline chromium and the Hall- Petch coefficient of body-centered cubic metals

    SciTech Connect (OSTI)

    Wu, Dong; Junyan, Zhang; Huang, J C; Bei, Hongbin; Nieh, Tai-Gang

    2013-01-01

    Nanocrystalline Cr (nc-Cr) was synthesized by electrodeposition. Samples with various grain sizes (19 57 nm) were prepared by annealing the as-deposited sample. Microstructures were examined using X-ray and electron microscopy, and the mechanical prop- erties were evaluated using nanoindentation. The strength of nc-Cr samples apparently obeyed the classical Hall Petch relationship. It was found that hardening potency caused by grain refinement was generally higher in body-centered cubic metals than that in face-centered cubic and hexagonal close-packed metals. A possible explanation was offered.

  9. Temperature dependence of the photo-induced inverse spin Hall effect in Au/InP hybrid structures

    SciTech Connect (OSTI)

    Khamari, Shailesh K. Porwal, S.; Dixit, V. K.; Sharma, T. K.

    2014-01-27

    Photo-induced Inverse Spin Hall Effect (ISHE) measurements on Au/InP hybrid structures are performed over a temperature range of 45 to 300 K. Dependence of the spin current density on the degree of circular polarization and also on the angle of incidence of laser beam confirms the ISHE origin of measured signal. The magnitude of ISHE increases with sample cooling. A numerical model based on the spin relaxation of non-equilibrium spin-polarized electrons is proposed for predicting the temperature dependence of ISHE. Our results indicate that the proposed device can be used as a spin photodetector over a wide temperature range.

  10. MO-PIS-Exhibit Hall-01: Tools for TG-142 Linac Imaging QA I

    SciTech Connect (OSTI)

    Clements, M; Wiesmeyer, M

    2014-06-15

    Partners in Solutions is an exciting new program in which AAPM partners with our vendors to present practical hands-on information about the equipment and software systems that we use in our clinics. The therapy topic this year is solutions for TG-142 recommendations for linear accelerator imaging QA. Note that the sessions are being held in a special purpose room built on the Exhibit Hall Floor, to encourage further interaction with the vendors. Automated Imaging QA for TG-142 with RIT Presentation Time: 2:45 3:15 PM This presentation will discuss software tools for automated imaging QA and phantom analysis for TG-142. All modalities used in radiation oncology will be discussed, including CBCT, planar kV imaging, planar MV imaging, and imaging and treatment coordinate coincidence. Vendor supplied phantoms as well as a variety of third-party phantoms will be shown, along with appropriate analyses, proper phantom setup procedures and scanning settings, and a discussion of image quality metrics. Tools for process automation will be discussed which include: RIT Cognition (machine learning for phantom image identification), RIT Cerberus (automated file system monitoring and searching), and RunQueueC (batch processing of multiple images). In addition to phantom analysis, tools for statistical tracking, trending, and reporting will be discussed. This discussion will include an introduction to statistical process control, a valuable tool in analyzing data and determining appropriate tolerances. An Introduction to TG-142 Imaging QA Using Standard Imaging Products Presentation Time: 3:15 3:45 PM Medical Physicists want to understand the logic behind TG-142 Imaging QA. What is often missing is a firm understanding of the connections between the EPID and OBI phantom imaging, the software algorithms that calculate the QA metrics, the establishment of baselines, and the analysis and interpretation of the results. The goal of our brief presentation will be to establish

  11. Spectral shape deformation in inverse spin Hall voltage in Y{sub 3}Fe{sub 5}O{sub 12}|Pt bilayers at high microwave power levels

    SciTech Connect (OSTI)

    Lustikova, J. Shiomi, Y.; Handa, Y.; Saitoh, E.

    2015-02-21

    We report on the deformation of microwave absorption spectra and of the inverse spin Hall voltage signals in thin film bilayers of yttrium iron garnet (YIG) and platinum at high microwave power levels in a 9.45-GHz TE{sub 011} cavity. As the microwave power increases from 0.15 to 200 mW, the resonance field shifts to higher values, and the initially Lorentzian spectra of the microwave absorption intensity as well as the inverse spin Hall voltage signals become asymmetric. The contributions from opening of the magnetization precession cone and heating of YIG cannot well reproduce the data. Control measurements of inverse spin Hall voltages on thin-film YIG|Pt systems with a range of line widths underscore the role of spin-wave excitations in spectral deformation.

  12. Spin current and inverse spin Hall effect in ferromagnetic metals probed by Y{sub 3}Fe{sub 5}O{sub 12}-based spin pumping

    SciTech Connect (OSTI)

    Wang, Hailong; Du, Chunhui; Chris Hammel, P. Yang, Fengyuan

    2014-05-19

    Using ferromagnetic (FM) resonance spin pumping, we observe injection of spin currents from Y{sub 3}Fe{sub 5}O{sub 12} (YIG) films to FM metals, including Ni{sub 81}Fe{sub 19} (Py), Fe, Co, and Ni, and detection of spin currents by inverse spin Hall effect (ISHE) in the FM metals. We obtain a high effective spin mixing conductance of 6.3 × 10{sup 18} m{sup −2} in a YIG/Cu/Py trilayer and a spin Hall angle of 0.020 for Py. The spin pumping signals in Fe, Co, and Ni confirm the mechanism of ISHE in FMs is the inverse process of the anomalous Hall effect.

  13. Time-domain detection of current controlled magnetization damping in Pt/Ni{sub 81}Fe{sub 19} bilayer and determination of Pt spin Hall angle

    SciTech Connect (OSTI)

    Ganguly, A.; Haldar, A.; Sinha, J.; Barman, A. E-mail: del.atkinson@durham.ac.uk; Rowan-Robinson, R. M.; Jaiswal, S.; Hindmarch, A. T.; Atkinson, D. A. E-mail: del.atkinson@durham.ac.uk

    2014-09-15

    The effect of spin torque from the spin Hall effect in Pt/Ni{sub 81}Fe{sub 19} rectangular bilayer film was investigated using time-resolved magneto-optical Kerr microscopy. Current flow through the stack resulted in a linear variation of effective damping up to ±7%, attributed to spin current injection from the Pt into the Ni{sub 81}Fe{sub 19}. The spin Hall angle of Pt was estimated as 0.11 ± 0.03. The modulation of the damping depended on the angle between the current and the bias magnetic field. These results demonstrate the importance of optical detection of precessional magnetization dynamics for studying spin transfer torque due to spin Hall effect.

  14. Temperature-driven band inversion in Pb0.77Sn0.23Se: Optical and Hall effect studies

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anand, Naween; Buvaev, Sanal; Hebard, A. F.; Tanner, D. B.; Chen, Zhiguo; Li, Zhiqiang; Choudhary, Kamal; Sinnott, S. B.; Gu, Genda; Martin, C.

    2014-12-23

    Optical and Hall-effect measurements have been performed on single crystals of Pb₀.₇₇Sn₀.₂₃Se, a IV-VI mixed chalcogenide. The temperature dependent (10–300 K) reflectance was measured over 40–7000 cm⁻¹ (5–870 meV) with an extension to 15,500 cm⁻¹ (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy opticalmore » spectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Thus, density function theory calculation for the electronic band structure also make similar predictions.« less

  15. The influence of an MgO nanolayer on the planar Hall effect in NiFe films

    SciTech Connect (OSTI)

    Li, Minghua; Zhao, Zhiduo; Ma, Lin; Lu, Xiangan; Teng, Jiao; Yu, Guanghua; Yu, Guoqiang; Amiri, Pedram Khalili; Wang, Kang L.; Zhou, Wenping

    2015-03-28

    The Planar Hall Effect (PHE) in NiFe films was studied using MgO as the buffer and capping layer to reduce the shunt effect. The thermal annealing was found to be effective in increasing the sensitivity. The sensitivity of the magnetic field reached as high as 865 V/AT in a MgO (3 nm)/NiFe (5 nm)/MgO(3 nm)/Ta(3 nm) structure after annealing at 500 °C for 2 h, which is close to the sensitivity of semiconductor Hall Effect (HE) sensors. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) were used to study the sample. The results show that the top crystallization of MgO and NiFe (111) texture were improved by proper annealing. The smooth and clear bottom MgO/NiFe and top NiFe/MgO interface is evident from our data. In addition, the shunt current of Ta was decreased. These combined factors facilitate the improvement of the sensitivity of the magnetic field.

  16. MO-PIS-Exhibit Hall-01: Imaging: CT Dose Optimization Technologies I

    SciTech Connect (OSTI)

    Denison, K; Smith, S

    2014-06-15

    Partners in Solutions is an exciting new program in which AAPM partners with our vendors to present practical hands-on information about the equipment and software systems that we use in our clinics. The imaging topic this year is CT scanner dose optimization capabilities. Note that the sessions are being held in a special purpose room built on the Exhibit Hall Floor, to encourage further interaction with the vendors. Dose Optimization Capabilities of GE Computed Tomography Scanners Presentation Time: 11:15 11:45 AM GE Healthcare is dedicated to the delivery of high quality clinical images through the development of technologies, which optimize the application of ionizing radiation. In computed tomography, dose management solutions fall into four categories: employs projection data and statistical modeling to decrease noise in the reconstructed image - creating an opportunity for mA reduction in the acquisition of diagnostic images. Veo represents true Model Based Iterative Reconstruction (MBiR). Using high-level algorithms in tandem with advanced computing power, Veo enables lower pixel noise standard deviation and improved spatial resolution within a single image. Advanced Adaptive Image Filters allow for maintenance of spatial resolution while reducing image noise. Examples of adaptive image space filters include Neuro 3-D filters and Cardiac Noise Reduction Filters. AutomA adjusts mA along the z-axis and is the CT equivalent of auto exposure control in conventional x-ray systems. Dynamic Z-axis Tracking offers an additional opportunity for dose reduction in helical acquisitions while SmartTrack Z-axis Tracking serves to ensure beam, collimator and detector alignment during tube rotation. SmartmA provides angular mA modulation. ECG Helical Modulation reduces mA during the systolic phase of the heart cycle. SmartBeam optimization uses bowtie beam-shaping hardware and software to filter off-axis x-rays - minimizing dose and reducing x-ray scatter. The DICOM

  17. TU-PIS-Exhibit Hall-01: CT Dose Optimization Technologies II

    SciTech Connect (OSTI)

    Driesser, I; Angel, E

    2014-06-15

    Partners in Solutions is an exciting new program in which AAPM partners with our vendors to present practical “hands-on” information about the equipment and software systems that we use in our clinics. The imaging topic this year is CT scanner dose optimization capabilities. Note that the sessions are being held in a special purpose room built on the Exhibit Hall Floor, to encourage further interaction with the vendors. Siemens‘ Commitment to the Right Dose in Computed Tomography Presentation Time: 11:15 - 11:45 AM Providing sustainable clinical results at highest patient safety: This is the challenge in medical imaging. Especially for Computed Tomography this means applying not simply the lowest, but the right dose for sound diagnostic imaging. Consequently, Siemens is committed to deliver the right dose in CT. In order to reduce radiation to the right dose, the first step is to provide the right dose technology. Through decades of research and development in CT imaging, Siemens CT has constantly introduced new ideas leading to a comprehensive portfolio of unique CARE technologies to deliver the right dose. For example automated kV adjustment based on patient size and the clinical question with CARE kV and three generations of iterative reconstruction. Based on the right dose technology, the next step is to actually scan at the right dose. For this, it is key to know the right dose targets for every examination. Siemens continuously involves CT experts to push developments further and outline how users can best adapt their procedures to the right dose. For users to know whether they met the right dose targets, it is therefore important to understand and monitor the actual absolute dose values. All scanners are delivered with defined default protocols which automatically use the available right dose technologies. Finally, to deliver the right dose not just in singular cases, but ideally to patients everywhere, organizations need then to manage dose across

  18. Investigation to the deep center related properties of low temperature grown InPBi with Hall and photoluminescence

    SciTech Connect (OSTI)

    Wang, Peng; Pan, Wenwu; Wu, Xiaoyan; Wang, Kai; Yue, Li; Gong, Qian; Wang, Shumin

    2015-12-15

    InP{sub 1-x}Bi{sub x} epilayers with bismuth (Bi) concentration x= 1.0% were grown on InP by gas source molecular beam epitaxy (GS-MBE) at low temperature (LT). Bi incorporation decreased the intrinsic free electron concentration of low temperature grown InP indicated by hall analysis. It is concluded that deep level center was introduced by Bi. Influence of Si doping on the InP{sub 1-x}Bi{sub x} films Photoluminescence (PL) was investigated. N-type doping in the InP{sub 1-x}Bi{sub x} epilayers was found to be effective at PL enhancement. Blue shift of InPBi PL emission wavelength was observed as the Si doping concentration increasing. Two independent peaks were fitted and their temperature dependence behavior was observed to be distinct obviously. Two individual radiative recombination processes were expected to be involved.

  19. Large size GEM for Super Bigbite Spectrometer (SBS) polarimeter for Hall A 12GeV program at JLab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gnanvo, Kondo; Liyanage, Nilanga; Nelyubin, Vladimir; Saenboonruang, Kiadtisak; Sacher, Seth; Wojtsekhowski, Bogdan

    2015-05-01

    We report on the R&D effort in the design and construction of a large size GEM chamber for the Proton Polarimeter of the Super Bigbite Spectrometer (SBS) in Hall A at Thomas Jefferson National Laboratory (JLab). The SBS Polarimeter trackers consist of two sets of four large chambers of size 200 cm x 60 cm2. Each chamber is a vertical stack of four GEM modules with an active area of 60 cm x 50 cm. We have built and tested several GEM modules and we describe in this paper the design and construction of the final GEM as well asmore » the preliminary results on performances from tests carried out in our detector lab and with test beams at (Fermilab).« less

  20. Attempt to measure magnetic hyperfine fields in metallic thin wires under spin Hall conditions using synchrotron-radiation Mssbauer spectroscopy

    SciTech Connect (OSTI)

    Mibu, K. Tanaka, M. A.; Mitsui, T.; Masuda, R.; Kitao, S.; Kobayashi, Y.; Seto, M.; Yoda, Y.

    2015-05-07

    Measurement of the magnetic hyperfine fields in metallic thin wires under spin Hall conditions was attempted using the emerging technique, synchrotron-radiation Mssbauer spectroscopy. A Mssbauer probe layer of {sup 57}Fe (0.2?nm), {sup 57}Fe (0.6?nm), or {sup 119}Sn (0.6?nm) was embedded as an electron spin detector near the surfaces of V, Au, Pt, and {sup 56}Fe wires. The magnitudes of the magnetic hyperfine fields at the {sup 57}Fe and {sup 119}Sn nuclear sites that could be enhanced by non-equilibrium conduction-electron spin polarization were measured both without and with the application of an electric current along the wire. Changes in the Mssbauer spectra were not clearly observed, indicating that the magnetic hyperfine field induced by non-equilibrium spin polarization is smaller than the detection limit at least for the measured systems and conditions.

  1. Large size GEM for Super Bigbite Spectrometer (SBS) polarimeter for Hall A 12GeV program at JLab

    SciTech Connect (OSTI)

    Gnanvo, Kondo; Liyanage, Nilanga; Nelyubin, Vladimir; Saenboonruang, Kiadtisak; Sacher, Seth; Wojtsekhowski, Bogdan

    2015-05-01

    We report on the R&D effort in the design and construction of a large size GEM chamber for the Proton Polarimeter of the Super Bigbite Spectrometer (SBS) in Hall A at Thomas Jefferson National Laboratory (JLab). The SBS Polarimeter trackers consist of two sets of four large chambers of size 200 cm x 60 cm2. Each chamber is a vertical stack of four GEM modules with an active area of 60 cm x 50 cm. We have built and tested several GEM modules and we describe in this paper the design and construction of the final GEM as well as the preliminary results on performances from tests carried out in our detector lab and with test beams at (Fermilab).

  2. Spin- and valley-dependent commensurability oscillations and electric-field-induced quantum Hall plateaux in periodically modulated silicene

    SciTech Connect (OSTI)

    Shakouri, Kh.; Peeters, F. M. [Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Vasilopoulos, P.; Vargiamidis, V. [Department of Physics, Concordia University, 7141 Sherbrooke Ouest Montral, Qubec H4B 1R6 (Canada); Hai, G.-Q. [Instituto de Fisica de So Carlos, Universidade de So Paulo, So Carlos, SP 13560-970 (Brazil)

    2014-05-26

    We study the commensurability oscillations in silicene subject to a perpendicular electric field E{sub z}, a weak magnetic field B, and a weak periodic potential V=V{sub 0}cos(Cy),C=2?/a{sub 0} with a{sub 0} its period. The field E{sub z} and/or the modulation lift the spin degeneracy of the Landau levels and lead to spin and valley resolved Weiss oscillations. The spin resolution is maximal when the field E{sub z} is replaced by a periodic one E{sub z}=E{sub 0}cos(Dy),D=2?/b{sub 0}, while the valley one is maximal for b{sub 0}?=?a{sub 0}. In certain ranges of B values, the current is fully spin or valley polarized. Additional quantum Hall conductivity plateaux arise due to spin and valley intra-Landau-level transitions.

  3. Intrinsic synchronization of an array of spin-torque oscillators driven by the spin-Hall effect

    SciTech Connect (OSTI)

    Siracusano, G. Puliafito, V.; Giordano, A.; Azzerboni, B.; Finocchio, G.; Tomasello, R.; La Corte, A.; Carpentieri, M.

    2015-05-07

    This paper micromagnetically studies the magnetization dynamics driven by the spin-Hall effect in a Platinum/Permalloy bi-layer. For a certain field and current range, the excitation of a uniform mode, characterized by a power with a spatial distribution in the whole ferromagnetic cross section, is observed. We suggest to use the ferromagnet of the bi-layer as basis for the realization of an array of spin-torque oscillators (STOs): the Permalloy ferromagnet will act as shared free layer, whereas the spacers and the polarizers are built on top of it. Following this strategy, the frequency of the uniform mode will be the same for the whole device, creating an intrinsic synchronization. The synchronization of an array of parallely connected STOs will allow to increase the output power, as necessary for technological applications.

  4. Giant spontaneous Hall effect in zero-moment Mn{sub 2}Ru{sub x}Ga

    SciTech Connect (OSTI)

    Thiyagarajah, Naganivetha; Lau, Yong-Chang; Betto, Davide; Borisov, Kiril; Coey, J. M. D.; Stamenov, Plamen; Rode, Karsten

    2015-03-23

    Spin-dependent transport properties of Mn{sub 2}Ru{sub x}Ga thin-films are studied as function of the Ru concentration and the substrate-induced strain. The large spontaneous Hall angle of 7.7% twenty times bigger than in other 3d metals is a signature of its half-metallicity. The compensation temperature where the magnetization of the two inequivalent antiferromagnetically coupled Mn sublattices cancel can be tuned by varying x or the biaxial strain. This zero-moment half metal is free from demagnetizing forces and creates no stray field, effectively removing two obstacles to integrating magnetic elements in densely packed, nanometer-scale memory elements, and millimeter-wave generators.

  5. Overview of torus magnet coil production at Fermilab for the Jefferson Lab 12-GeV Hall B upgrade

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Krave, S.; Velev, G.; Makarov, A.; Nobrega, F.; Kiemschies, O.; Robotham, B.; Elementi, L.; Elouadrhiri, Latifa; Luongo, Cesar; Kashy, David H.; et al

    2016-02-29

    Fermi National Accelerator Laboratory (Fermilab) fabricated the torus magnet coils for the 12 GeV Hall B upgrade at Jefferson Laboratory (JLab). The production consisted of 6 large superconducting coils for the magnet and 2 spare coils. The toroidal field coils are approximately 2 m x 4 m x 5 cm thick. Each of these coils consists of two layers, each of which has 117 turns of copper-stabilized superconducting cable which will be conduction cooled by helium gas. Due to the size of the coils and their unique geometry, Fermilab designed and fabricated specialized tooling and, together with JLab, developed uniquemore » manufacturing techniques for each stage of the coil construction. In conclusion, this paper describes the tooling and manufacturing techniques required to produce the six production coils and two spare coils needed by the project.« less

  6. Spin Hall magnetoresistance at Pt/CoFe{sub 2}O{sub 4} interfaces and texture effects

    SciTech Connect (OSTI)

    Isasa, Miren; Bedoya-Pinto, Amilcar; Vlez, Sal; Golmar, Federico; Snchez, Florencio; Fontcuberta, Josep; Hueso, Luis E.; Casanova, Flix

    2014-10-06

    We report magnetoresistance measurements on thin Pt bars grown on epitaxial (001) and (111) CoFe{sub 2}O{sub 4} (CFO) ferrimagnetic insulating films. The results can be described in terms of the recently discovered spin Hall magnetoresistance (SMR). The magnitude of the SMR depends on the interface preparation conditions, being optimal when the Pt/CFO samples are prepared in situ, in a single process. The spin-mixing interface conductance, the key parameter governing SMR and other relevant spin-dependent phenomena, such as spin pumping or spin Seebeck effect, is found to be different depending on the crystallographic orientation of CFO, highlighting the role of the composition and density of magnetic ions at the interface on spin mixing.

  7. Cavity Design, Fabrication and Commission Performance of a 750MHz, 4-rod Separator for CEBAF 4-Hall Beam Delivery System

    SciTech Connect (OSTI)

    Wang, Haipeng; Cheng, Guangfeng; Turlington, Larry T.; Wissmann, Mark J.

    2015-09-01

    A short version of the original CEBAF normal conducting 4-rod separator cavity has been developed into a 750MHz one * since the concept of simultaneous 4-hall operation for CEBAF is introduced **. This work has been advanced further based on the EM design optimization, bench measurement and by conducting RF-thermal coupled simulation using CST and ANSYS to confirm the cavity tuning and thermal performance. The cavity fabrication used matured technology like copper plating and machining. The cavity flanges, couplers, tuners and cooling channels adopted consistent/compatible hardware with the existing 500MHz cavities. The electromagnetic and thermal design simulations have greatly reduced the prototyping and bench tuning time of the first prototype. Four production cavities have reached a typical 1.94MV kick voltage or 3.0kW wall loss on each cavity after a minor multipactoring or no processing, 7.5% overhead power than the design specification.

  8. Electron-electron interaction and the universality of critical indices for quantum Hall effect plateau-plateau transitions in n-InGaAs/GaAs nanostructures with double quantum wells

    SciTech Connect (OSTI)

    Arapov, Yu. G.; Gudina, S. V. Klepikova, A. S.; Neverov, V. N.; Shelushinina, N. G.; Yakunin, M. V.

    2015-02-15

    The dependences of the longitudinal and Hall resistances on a magnetic field in the integer quantum Hall effect regime in n-InGaAs/GaAs heterostructures with a double quantum well are measured in the range of magnetic fields B = 0–16 T and temperatures T = 0.05–4.2 K, before and after infrared illumination. Analysis of the temperature dependence of the width of transitions between plateaus of the quantum Hall effect is performed in the scope of the scaling hypothesis allowing for electron-electron interaction effects.

  9. Y{sub 3}Fe{sub 5}O{sub 12} spin pumping for quantitative understanding of pure spin transport and spin Hall effect in a broad range of materials (invited)

    SciTech Connect (OSTI)

    Du, Chunhui; Wang, Hailong; Hammel, P. Chris; Yang, Fengyuan

    2015-05-07

    Using Y{sub 3}Fe{sub 5}O{sub 12} (YIG) thin films grown by our sputtering technique, we study dynamic spin transport in nonmagnetic, ferromagnetic, and antiferromagnetic (AF) materials by ferromagnetic resonance spin pumping. From both inverse spin Hall effect and damping enhancement, we determine the spin mixing conductance and spin Hall angle in many metals. Surprisingly, we observe robust spin conduction in AF insulators excited by an adjacent YIG at resonance. This demonstrates that YIG spin pumping is a powerful and versatile tool for understanding spin Hall physics, spin-orbit coupling, and magnetization dynamics in a broad range of materials.

  10. Intrinsic quantum anomalous Hall effect in the kagome lattice Cs2LiMn3F12

    SciTech Connect (OSTI)

    Xu, Gang; Lian, Biao; Zhang, Shou -Cheng

    2015-10-27

    In a kagome lattice, the time reversal symmetry can be broken by a staggered magnetic flux emerging from ferromagnetic ordering and intrinsic spin-orbit coupling, leading to several well-separated nontrivial Chern bands and intrinsic quantum anomalous Hall effect. Based on this idea and ab initio calculations, we propose the realization of the intrinsic quantum anomalous Hall effect in the single layer Cs2Mn3F12 kagome lattice and on the (001) surface of a Cs2LiMn3F12 single crystal by modifying the carrier coverage on it, where the band gap is around 20 meV. Furthermore, a simplified tight binding model based on the in-plane ddσ antibonding states is constructed to understand the topological band structures of the system.

  11. Anomalous Hall effect in epitaxial ferrimagnetic anti-perovskite Mn{sub 4−x}Dy{sub x}N films

    SciTech Connect (OSTI)

    Meng, M.; Wu, S. X. Zhou, W. Q.; Ren, L. Z.; Wang, Y. J.; Wang, G. L.; Li, S. W.

    2015-08-07

    Anomalous Hall effect (AHE) has been studied for ferrimagnetic antiperovskite Mn{sub 4−x}Dy{sub x}N films grown by molecular-beam epitaxy. The introduction of Dy changes the AHE dramatically, even changes its sign, while the variations in magnetization are negligible. Two sign reversals of the AHE (negative-positive-negative) are ascribed to the variation of charge carriers as a result of Fermi surface reconstruction. We further demonstrate that the AHE current J{sub AH} is dissipationless (independent of the scattering rate), by confirming that anomalous Hall conductivity, σ{sub AH}, is proportional to the carrier density n at 5 K. Our study may provide a route to further utilize antiperovskite manganese nitrides in spintronics.

  12. Microsoft PowerPoint - SRSCRO Public Town Hall Mtg - SRS Missions & Funding FY 14 & 15 - 17 Apr 14.ppt [Repaired]

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    This image cannot currently be displayed. This image cannot currently be displayed. Savannah River Site Missions, Accomplishments and Funding SRS Community Reuse Organization Public Town Hall Meeting April 17, 2014 Dr. Dave Moody Site Manager DOE-Savannah River Doug Hintze Assistant Manager for Mission Support/Acting Chief Financial Officer DOE-Savannah River This image cannot currently be displayed. www.energy.gov/EM This image cannot currently be displayed. Purpose Ø Provide an overview of

  13. Note: Fiber optic transport probe for Hall measurements under light and magnetic field at low temperatures: Case study of a two dimensional electron gas

    SciTech Connect (OSTI)

    Bhadauria, P. P. S.; Gupta, Anurag; Kumar, Pramod; Dogra, Anjana; Budhani, R. C.

    2015-05-15

    A fiber optic based probe is designed and developed for electrical transport measurements in presence of quasi-monochromatic (360–800 nm) light, varying temperature (T = 1.8–300 K), and magnetic field (B = 0–7 T). The probe is tested for the resistivity and Hall measurements performed on a LaAlO{sub 3}–SrTiO{sub 3} heterointerface system with a conducting two dimensional electron gas.

  14. Influence of Mn concentration on magnetic topological insulator MnxBi2−xTe3 thin-film Hall-effect sensor

    SciTech Connect (OSTI)

    Ni, Y.; Zhang, Z.; Nlebedim, I. C.; Hadimani, R. L.; Jiles, D. C.

    2015-06-11

    Hall-effect (HE) sensors based on high-quality Mn-doped Bi2Te3 topological insulator (TI) thin films have been systematically studied in this paper. Improvement of Hall sensitivity is found after doping the magnetic element Mn into Bi2Te3. The sensors with low Mn concentrations, MnxBi2-xTe3, x = 0.01 and 0.08 show the linear behavior of Hall resistance with sensitivity about 5 Ω/T. And their Hall sensitivity shows weak dependence on temperature. For sensors with high Mn concentration (x = 0.23), the Hall resistance with respect to magnetic field shows a hysteretic behavior. Moreover, its sensitivity shows almost eight times as high as that of the HE sensors with low Mn concentration. The highest sensitivity can reach 43 Ω/T at very low magnetic field. This increase of Hall sensitivity is caused by the occurrence of anomalous HE (AHE) after ferromagnetic phase transition. Our work indicates that the magnetic-element-doped TIs with AHE are good candidates for HE sensors.

  15. Dependence of inverse-spin Hall effect and spin-rectified voltage on tantalum thickness in Ta/CoFeB bilayer structure

    SciTech Connect (OSTI)

    Kim, Sang-Il; Seo, Min-Su; Park, Seung-Young; Kim, Dong-Jun; Park, Byong-Guk

    2015-01-19

    Ta-layer thickness (t{sub Ta}) dependence of the measured DC voltage V from the inverse-spin Hall effect (ISHE) in Ta/CoFeB bilayer structure is experimentally investigated using the ferromagnetic resonance in the TE{sub 011} resonant cavity. The ISHE signals excluding the spin-rectified effect (SRE) were separated from the fitted curve of V against t{sub Ta}. For t{sub Ta} ≈ λ{sub Ta} (Ta-spin diffusion length = 2.7 nm), the deviation in ISHE voltage V{sub ISH} between the experimental and theoretical values is significantly increased because of the large SRE contribution, which also results in a large deviation in the spin Hall angle θ{sub SH} (from 10% to 40%). However, when t{sub Ta} ≫ λ{sub Ta}, the V{sub ISH} values are consistent with theoretical values because the SRE terms become negligible, which subsequently improves the accuracy of the obtained θ{sub SH} within 4% deviation. The results will provide an outline for an accurate estimation of the θ{sub SH} for materials with small λ value, which would be useful for utilizing the spin Hall effect in a 3-terminal spintronic devices in which magnetization can be controlled by in-plane current.

  16. Shockley-Read-Hall recombination in pre-filled and photo-filled intermediate band solar cells

    SciTech Connect (OSTI)

    Mayani, Maryam Gholami; Reenaas, Turid Worren

    2014-08-18

    In this work, we study how Shockley-Read-Hall (SRH) recombination via energy levels in the bandgap, caused by defects or impurities, affects the performance of both photo-filled and pre-filled intermediate band solar cells (IBSCs). For a pre-filled cell, the IB is half-filled in equilibrium, while it is empty for the photo-filled cell in equilibrium. The energy level, density, and capture cross-sections of the defects/impurities are varied systematically. We find that the photo-filled cells are, in general, less efficient than pre-filled cells, except when the defect level is between the conduction band and the IB. In that case, for a range of light intensities, the photo-filled cell performs better than the pre-filled. When the defect level is at the same energy as the IB, the efficiency is above 82% of the defect-free case, when less than 50% of the states at the IB lead to SRH recombination. This shows that even if SRH recombination via the IB takes place, high efficiencies can be achieved. We also show that band gap optimization can be used to reduce the SRH recombination.

  17. Quantum anomalous Hall effect and a nontrivial spin-texture in ultra-thin films of magnetic topological insulators

    SciTech Connect (OSTI)

    Duong, Le Quy; Das, Tanmoy; Feng, Y. P.; Lin, Hsin

    2015-05-07

    We study the evolution of quantum anomalous Hall (QAH) effect for a Z{sub 2} topological insulator (TI) thin films in a proximity induced magnetic phase by a realistic layered k·p model with interlayer coupling. We examine three different magnetic configurations in which ferromagnetic (FM) layer(s) is added either from one side (FM-TI), from both sides (FM-TI-FM), or homogeneously distributed (magnetically doped) in a TI slab. We map out the thickness-dependent topological phase diagram under various experimental conditions. The critical magnetic exchange energy for the emergence of QAH effect in the latter two cases decreases monotonically with increasing number of quintuple layers (QLs), while it becomes surprisingly independent of the film thickness in the former case. The gap size of the emergent QAH insulator depends on the non-magnetic “parent” gap of the TI thin film and is tuned by the FM exchange energy, opening a versatile possibility to achieve room-temperature QAH insulator in various topological nanomaterials. Finally, we find that the emergent spin-texture in the QAH effect is very unconventional, non-“hedgehog” type; and it exhibits a chiral out-of-plane spin-flip texture within the same valence band which is reminiscent of dynamical “skyrmion” pattern, except our results are in the momentum space.

  18. Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhou, Miao; Ming, Wenmei; Liu, Zheng; Wang, Zhengfei; Yao, Yugui; Liu, Feng

    2014-11-19

    For potential applications in spintronics and quantum computing, it is desirable to place a quantum spin Hall insulator [i.e., a 2D topological insulator (TI)] on a substrate while maintaining a large energy gap. Here, we demonstrate a unique approach to create the large-gap 2D TI state on a semiconductor surface, based on first-principles calculations and effective Hamiltonian analysis. We show that when heavy elements with strong spin orbit coupling (SOC) such as Bi and Pb atoms are deposited on a patterned H-Si(111) surface into a hexagonal lattice, they exhibit a 2D TI state with a large energy gap of ≥0.5more » eV. The TI state arises from an intriguing substrate orbital filtering effect that selects a suitable orbital composition around the Fermi level, so that the system can be matched onto a four-band effective model Hamiltonian. Furthermore, it is found that within this model, the SOC gap does not increase monotonically with the increasing strength of SOC. These interesting results may shed new light in future design and fabrication of large-gap topological quantum states.« less

  19. Berry phase mechanism of the anomalous Hall effect in a disordered two-dimensional magnetic semiconductor structure.

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Oveshnikov, L. N.; Kulbachinskii, V. A.; Davydov, A. B.; Aronzon, B. A.; Rozhansky, I. V.; Averkiev, N. S.; Kugel, K. I.; Tripathi, V.

    2015-11-24

    In this study, the anomalous Hall effect (AHE) arises from the interplay of spin-orbit interactions and ferromagnetic order and is a potentially useful probe of electron spin polarization, especially in nanoscale systems where direct measurement is not feasible. While AHE is rather well-understood in metallic ferromagnets, much less is known about the relevance of different physical mechanisms governing AHE in insulators. As ferromagnetic insulators, but not metals, lend themselves to gatecontrol of electron spin polarization, understanding AHE in the insulating state is valuable from the point of view of spintronic applications. Among the mechanisms proposed in the literature for AHEmore » in insulators, the one related to a geometric (Berry) phase effect has been elusive in past studies. The recent discovery of quantized AHE in magnetically doped topological insulators - essentially a Berry phase effect - provides strong additional motivation to undertake more careful search for geometric phase effects in AHE in the magnetic semiconductors. Here we report our experiments on the temperature and magnetic field dependences of AHE in insulating, strongly-disordered two-dimensional Mn delta-doped semiconductor heterostructures in the hopping regime. In particular, it is shown that at sufficiently low temperatures, the mechanism of AHE related to the Berry phase is favoured.« less

  20. Berry phase mechanism of the anomalous Hall effect in a disordered two-dimensional magnetic semiconductor structure.

    SciTech Connect (OSTI)

    Oveshnikov, L. N.; Kulbachinskii, V. A.; Davydov, A. B.; Aronzon, B. A.; Rozhansky, I. V.; Averkiev, N. S.; Kugel, K. I.; Tripathi, V.

    2015-11-24

    In this study, the anomalous Hall effect (AHE) arises from the interplay of spin-orbit interactions and ferromagnetic order and is a potentially useful probe of electron spin polarization, especially in nanoscale systems where direct measurement is not feasible. While AHE is rather well-understood in metallic ferromagnets, much less is known about the relevance of different physical mechanisms governing AHE in insulators. As ferromagnetic insulators, but not metals, lend themselves to gatecontrol of electron spin polarization, understanding AHE in the insulating state is valuable from the point of view of spintronic applications. Among the mechanisms proposed in the literature for AHE in insulators, the one related to a geometric (Berry) phase effect has been elusive in past studies. The recent discovery of quantized AHE in magnetically doped topological insulators - essentially a Berry phase effect - provides strong additional motivation to undertake more careful search for geometric phase effects in AHE in the magnetic semiconductors. Here we report our experiments on the temperature and magnetic field dependences of AHE in insulating, strongly-disordered two-dimensional Mn delta-doped semiconductor heterostructures in the hopping regime. In particular, it is shown that at sufficiently low temperatures, the mechanism of AHE related to the Berry phase is favoured.

  1. Lodging | Open Energy Information

    Open Energy Info (EERE)

    Lodging Jump to: navigation, search Building Type Lodging Definition Buildings used to offer multiple accommodations for short-term or long-term residents, including skilled...

  2. Correction to the paper “a simple model to determine the interrelation between the integral characteristics of hall thrusters” [Plasma Physics Reports 40, 229 (2014)

    SciTech Connect (OSTI)

    Shumilin, V. P.; Shumilin, A. V.; Shumilin, N. V.

    2015-11-15

    The paper is devoted to comparison of experimental data with theoretical predictions concerning the dependence of the current of accelerated ions on the operating voltage of a Hall thruster with an anode layer. The error made in the paper published by the authors in Plasma Phys. Rep. 40, 229 (2014) occurred because of a misprint in the Encyclopedia of Low-Temperature Plasma. In the present paper, this error is corrected. It is shown that the simple model proposed in the above-mentioned paper is in qualitative and quantitative agreement with experimental results.

  3. Photon energy dependence of photo-induced inverse spin-Hall effect in Pt/GaAs and Pt/Ge

    SciTech Connect (OSTI)

    Isella, Giovanni Bottegoni, Federico; Ferrari, Alberto; Finazzi, Marco; Ciccacci, Franco

    2015-06-08

    We report the photon energy dependence of photo-induced inverse spin Hall effect (ISHE) in Pt/GaAs and Pt/Ge Schottky junctions. The experimental results are compared with a spin drift-diffusion model, which highlights the role played by the different spin lifetime in the two semiconductors, in determining the energy dependence of the ISHE signal detected in the Pt layer. The good qualitative agreement between experiments and modelling indicates that photo-induced ISHE can be used as a tool to characterize spin lifetime in semiconductors.

  4. Determination of the normal and anomalous hall effect coefficients in ferromagnetic Ni{sub 50}Mn{sub 35}In{sub 15-x}Si{sub x} Heusler alloys at the martensitic transformation

    SciTech Connect (OSTI)

    Granovskii, A. B. Prudnikov, V. N.; Kazakov, A. P.; Zhukov, A. P.; Dubenko, I. S.

    2012-11-15

    The magnetization, the electrical resistivity, the magnetoresistance, and the Hall resistivity of Ni{sub 50}Mn{sub 35}In{sub 15-x}Si{sub x} (x = 1.0, 3.0, 4.0) Heusler alloys are studied at T = 80-320 K. The martensitic transformation in these alloys occurs at T = 220-280 K from the high-temperature ferromagnetic austenite phase into the low-temperature martensite phase having a substantially lower magnetization. A method is proposed to determine the normal and anomalous Hall effect coefficients in the presence of magnetoresistance and a possible magnetization dependence of these coefficients. The resistivity of the alloys increases jumpwise during the martensitic transformation, reaches 150-200 {mu}{Omega} cm, and is almost temperature-independent. The normal Hall effect coefficient is negative, is higher than that of nickel by an order of magnitude at T = 80 K, decreases monotonically with increasing temperature, approaches zero in austenite, and does not undergo sharp changes in the vicinity of the martensitic transformation. At x = 3, a normal Hall effect nonlinear in magnetization is detected in the immediate vicinity of the martensitic transformation. The temperature dependences of the anomalous Hall effect coefficient in both martensite and austenite and, especially, in the vicinity of the martensitic transformation cannot be described in terms of the skew scattering, the side jump, and the Karplus-Lutinger mechanisms from the anomalous Hall effect theory. The possible causes of this behavior of the magnetotransport properties in Heusler alloys are discussed.

  5. Workforce Diversity Town Hall

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2011-08-18

    On August 18, 2011, President Obama issued an Executive Order, "Establishing a Coordinated Government-wide Initiative to Promote Diversity and Inclusion in the Federal Workforce," directing federal agencies to develop strategic plans to recruit and retain a more diverse workforce.

  6. Hall A Virtual Tour

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  7. Hall B Virtual Tour

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  8. Hall C Virtual Tour

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  9. Hall_A

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  10. Hall_B

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    N∆ Transition Form Factor & Multipoles The CEBAF Large Acceptance Spectrometer (CLAS) www.jlab.org K. Joo et al., Phys. Rev. Lett. 88 (2002) 122001 F.X. Girod et al. (CLAS Collaboration), Phys. Rev. Lett. 100 (2008) 162002 L. El Fassi et al. (CLAS Collaboration), submitted for publication (2011)

  11. Hall_C

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  12. Hall_D

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dudek et al., Hadron Spectrum Collab. PRD 82:034508 (2010)

  13. Hall and Seebeck measurements estimate the thickness of a (buried) carrier system: Identifying interface electrons in In-doped SnO{sub 2} films

    SciTech Connect (OSTI)

    Papadogianni, Alexandra; Bierwagen, Oliver; White, Mark E.; Speck, James S.; Galazka, Zbigniew

    2015-12-21

    We propose a simple method based on the combination of Hall and Seebeck measurements to estimate the thickness of a carrier system within a semiconductor film. As an example, this method can distinguish “bulk” carriers, with homogeneous depth distribution, from “sheet” carriers, that are accumulated within a thin layer. The thickness of the carrier system is calculated as the ratio of the integral sheet carrier concentration, extracted from Hall measurements, to the volume carrier concentration, derived from the measured Seebeck coefficient of the same sample. For rutile SnO{sub 2}, the necessary relation of Seebeck coefficient to volume electron concentration in the range of 3 × 10{sup 17} to 3 × 10{sup 20 }cm{sup −3} has been experimentally obtained from a set of single crystalline thin films doped with varying Sb-doping concentrations and unintentionally doped bulk samples, and is given as a “calibration curve.” Using this calibration curve, our method demonstrates the presence of interface electrons in homogeneously deep-acceptor (In) doped SnO{sub 2} films on sapphire substrates.

  14. Micro-focused Brillouin light scattering study of the magnetization dynamics driven by Spin Hall effect in a transversely magnetized NiFe nanowire

    SciTech Connect (OSTI)

    Madami, M. Carlotti, G.; Gubbiotti, G.; Tacchi, S.; Siracusano, G.; Finocchio, G.; Carpentieri, M.

    2015-05-07

    We employed micro-focused Brillouin light scattering to study the amplification of the thermal spin wave eigenmodes by means of a pure spin current, generated by the spin-Hall effect, in a transversely magnetized Pt(4 nm)/NiFe(4 nm)/SiO{sub 2}(5 nm) layered nanowire with lateral dimensions 500 × 2750 nm{sup 2}. The frequency and the cross section of both the center (fundamental) and the edge spin wave modes have been measured as a function of the intensity of the injected dc electric current. The frequency of both modes exhibits a clear redshift while their cross section is greatly enhanced on increasing the intensity of the injected dc. A threshold-like behavior is observed for a value of the injected dc of 2.8 mA. Interestingly, an additional mode, localized in the central part of the nanowire, appears at higher frequency on increasing the intensity of the injected dc above the threshold value. Micromagnetic simulations were used to quantitatively reproduce the experimental results and to investigate the complex non-linear dynamics induced by the spin-Hall effect, including the modification of the spatial profile of the spin wave modes and the appearance of the extra mode above the threshold.

  15. Disorder-induced anomalously signed Hall effect in crystalline GeTe/Sb{sub 2}Te{sub 3} superlattice-like materials

    SciTech Connect (OSTI)

    Tong, H.; Yu, N. N.; Yang, Z.; Cheng, X. M.; Miao, X. S.

    2015-08-21

    Opposite to the almost persistent p-type conductivity of the crystalline chalcogenides along the GeTe-Sb{sub 2}Te{sub 3} tie line, n-type Hall mobility is observed in crystalline GeTe/Sb{sub 2}Te{sub 3} superlattice-like material (SLL) with a short period length. We suggest that this unusual carrier characteristic originates from the structural disorder introduced by the lattice strain and dangling bonds at the SLL interfaces, which makes the crystalline SLLs behave like the amorphous chalcogenides. Detailed structural disorder in crystalline SLL has been studied by Raman scattering, X-ray photoelectron spectroscopy, as well as Variable-energy positron annihilation spectroscopy measurements. First-principles calculations results show that this structural disorder gives rise to three-site junctions that dominate the charge transport as the period length decreases and result in the anomalously signed Hall effect in the crystalline SLL. Our findings indicate a similar tetrahedral structure in the amorphous and crystalline states of SLLs, which can significantly reduce the entropy difference. Due to the reduced entropy loss and increased resistivity of crystalline phase introduced by disorder, it is not surprising that the SLLs exhibit extremely lower RESET current and power consumption.

  16. Single-valley quantum Hall ferromagnet in a dilute MgxZn1-xO/ZnO strongly correlated two-dimensional electron system

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kozuka, Y.; Tsukazaki, A.; Maryenko, D.; Falson, J.; Bell, C.; Kim, M.; Hikita, Y.; Hwang, H. Y.; Kawasaki, M.

    2012-02-03

    We investigate the spin susceptibility (g*m*) of dilute two-dimensional (2D) electrons confined at the MgxZn1-xO/ZnO heterointerface. Magnetotransport measurements show a four-fold enhancement of g*m*, dominated by the increase in the Landé g-factor. The g-factor enhancement leads to a ferromagnetic instability of the electron gas as evidenced by sharp resistance spikes. At high magnetic field, the large g*m* leads to full spin polarization, where we found sudden increase in resistance around the filling factors of half-integer, accompanied by complete disappearance of fractional quantum Hall (QH) states. Along with its large effective mass and the high electron mobility, our result indicates thatmore » the ZnO 2D system is ideal for investigating the effect of electron correlations in the QH regime.« less

  17. Highly tunable quantum Hall far-infrared photodetector by use of GaAs/Al{sub x}Ga{sub 1?x}As-graphene composite material

    SciTech Connect (OSTI)

    Tang, Chiu-Chun [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Ling, D. C. [Department of Physics, Tamkang University, Tamsui Dist., New Taipei City 25137, Taiwan (China); Chi, C. C.; Chen, Jeng-Chung [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2014-11-03

    We have developed a highly tunable, narrow band far-infrared (FIR) photodetector which utilizes the characteristic merits of graphene and two-dimensional electron gas (2DEG) in GaAs/Al{sub x}Ga{sub 1?x}As heterostructure in the Quantum Hall states (QHS). The heterostructure surface is covered with chemical vapor-deposited graphene, which functions as a transparent top-gate to vary the electron density of the 2DEG. FIR response observed in the vicinity of integer QH regime can be effectively tuned in a wide range of 27102?cm{sup ?1} with a bias voltage less than ?1?V. In addition, we have found that the presence of graphene can genuinely modulate the photoresponse. Our results demonstrate a promising direction for realizing a tunable long-wavelength FIR detector using QHS in GaAs 2DEG/ graphene composite material.

  18. Study of non-linear Hall effect in nitrogen-grown ZnO microstructure and the effect of H{sup +}-implantation

    SciTech Connect (OSTI)

    Kumar, Yogesh Bern, Francis; Barzola-Quiquia, Jose; Lorite, Israel; Esquinazi, Pablo

    2015-07-13

    We report magnetotransport studies on microstructured ZnO film grown by pulsed laser deposition in N{sub 2} atmosphere on a-plane Al{sub 2}O{sub 3} substrates and the effect of low energy H{sup +}-implantation. Non-linearity has been found in the magnetic field dependent Hall resistance, which decreases with temperature. We explain this effect with a two-band model assuming the conduction through two different parallel channels having different types of charge carriers. Reduced non-linearity after H{sup +}-implantation in the grown film is due to the shallow-donor effect of hydrogen giving rise to an increment in the electron density, reducing the effect of the other channel.

  19. First-principles study on the relationship between magnetic anisotropy and anomalous Hall effect of bct-Fe{sub 50}Co{sub 50}

    SciTech Connect (OSTI)

    Hyodo, Kazushige Sakuma, Akimasa; Kota, Yohei

    2014-05-07

    We studied quantitative relationship between the intrinsic anomalous Hall conductivity (σ{sub xy}) and the uniaxial magnetic anisotropy constant (K{sub u}) of bct-Fe{sub 50}Co{sub 50} using first-principles calculation because these quantities originate from spin-orbit interaction. We found that the obtained σ{sub xy} and K{sub u} with changing the axial ratio c/a (1≤c/a≤√(2)) exhibit similar behavior mainly arising from the common band mixing of the minority-spin d{sub xy} and d{sub x{sup 2}−y{sup 2}} states near the Fermi level which is sensitive to c/a.

  20. Observation of the inverse spin Hall effect in ZnO thin films: An all-electrical approach to spin injection and detection

    SciTech Connect (OSTI)

    Prestgard, Megan C.; Tiwari, Ashutosh

    2014-03-24

    The inverse spin Hall effect (ISHE) is a newly discovered, quantum mechanical phenomenon where an applied spin current results in the generation of an electrical voltage in the transverse direction. It is anticipated that the ISHE can provide a more simple way of measuring spin currents in spintronic devices. The ISHE was first observed in noble metals that exhibit strong spin-orbit coupling. However, recently, the ISHE has been detected in conventional semiconductors (such as Si and Ge), which possess weak spin-orbit coupling. This suggests that large-spin orbit coupling is not a requirement for observing the ISHE. In this paper, we are reporting the observation of the ISHE in an alternative semiconductor material, zinc oxide (ZnO) using all-electrical means. In our study, we found that when a spin-polarized current is injected into the ZnO film from a NiFe ferromagnetic injector via an MgO tunnel barrier layer, a voltage transverse to both the direction of the current as well as its spin-polarization is generated in the ZnO layer. The polarity of this voltage signal was found to flip on reversing the direction of the injected current as well as on reversing the polarization of the current, consistent with the predictions of the ISHE process. Through careful analysis of the ISHE data, we determined a spin-Hall angle of approximately 1.651 × 10{sup −2} for ZnO, which is two orders of magnitude higher than that of silicon. Observation of a detectable room-temperature ISHE signal in ZnO via electrical injection and detection is a groundbreaking step that opens a path towards achieving transparent spin detectors for next-generation spintronic device technology.

  1. Measurement of XeI and XeII velocity in the near exit plane of a low-power Hall effect thruster by light induced fluorescence spectroscopy

    SciTech Connect (OSTI)

    Dancheva, Y.; Biancalana, V.; Pagano, D.; Scortecci, F.

    2013-06-15

    Near exit plane non-resonant light induced fluorescence spectroscopy is performed in a Hall effect low-power Xenon thruster at discharge voltage of 250 V and anode flow rate of 0.7 mg/s. Measurements of the axial and radial velocity components are performed, exciting the 6s{sup 2}[3/2]{sub 2}{sup o}{yields}6p{sup 2}[3/2]{sub 2} transition at 823.16 nm in XeI and the 5d[4]{sub 7/2}{yields}6p[3]{sub 5/2}{sup o} transition at 834.724 nm in XeII. No significant deviation from the thermal velocity is observed for XeI. Two most probable ion velocities are registered at a given position with respect to the thruster axis, which are mainly attributed to different areas of creation of ions inside the acceleration channel. The spatial resolution of the set-up is limited by the laser beam size (radius of the order of 0.5 mm) and the fluorescence collection optics, which have a view spot diameter of 8 mm.

  2. Evidence of a Shockley-Read-Hall Defect State Independent of Band-Edge Energy in InAs/In(As,Sb) Type-II Superlattices

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aytac, Y.; Olson, B. V.; Kim, J. K.; Shaner, E. A.; Hawkins, S. D.; Klem, J. F.; Flatté, M. E.; Boggess, T. F.

    2016-05-24

    A set of seven InAs/InAsSb type-II superlattices (T2SLs) were designed to have speci c bandgap energies between 290 meV (4.3 m) and 135 meV (9.2 m) in order to study the e ects of the T2SL bandgap energy on the minority carrier lifetime. A temperature dependent optical pump-probe technique is used to measure the carrier lifetimes, and the e ect of a mid-gap defect level on the carrier recombination dynamics is reported. The Shockley-Read-Hall (SRH) defect state is found to be at energy of approximately -250 12 meV relative to the valence band edge of bulk GaSb for the entiremore » set of T2SL structures, even though the T2SL valence band edge shifts by 155 meV on the same scale. These results indicate that the SRH defect state in InAs/InAsSb T2SLs is singular and is nearly independent of the exact position of the T2SL bandgap or band edge energies. They also suggest the possibility of engineering the T2SL structure such that the SRH state is removed completely from the bandgap, a result that should signi cantly increase the minority carrier lifetime.« less

  3. Electron effective mass in Al{sub 0.72}Ga{sub 0.28}N alloys determined by mid-infrared optical Hall effect

    SciTech Connect (OSTI)

    Schöche, S. Kühne, P.; Hofmann, T.; Schubert, M.; Nilsson, D.; Kakanakova-Georgieva, A.; Janzén, E.; Darakchieva, V.

    2013-11-18

    The effective electron mass parameter in Si-doped Al{sub 0.72}Ga{sub 0.28}N is determined to be m{sup ∗}=(0.336±0.020) m{sub 0} from mid-infrared optical Hall effect measurements. No significant anisotropy of the effective electron mass parameter is found supporting theoretical predictions. Assuming a linear change of the effective electron mass with the Al content in AlGaN alloys and m{sup ∗}=0.232 m{sub 0} for GaN, an average effective electron mass of m{sup ∗}=0.376 m{sub 0} can be extrapolated for AlN. The analysis of mid-infrared spectroscopic ellipsometry measurements further confirms the two phonon mode behavior of the E{sub 1}(TO) and one phonon mode behavior of the A{sub 1}(LO) phonon mode in high-Al-content AlGaN alloys as seen in previous Raman scattering studies.

  4. Fourfold symmetric planar Hall effect in epitaxial La{sub 1−x}Sr{sub x}CoO{sub 3} thin films

    SciTech Connect (OSTI)

    Cui, W. Y.; Li, P.; Bai, H. L.

    2015-04-07

    The effect of Sr concentration on the planar Hall effect (PHE) in epitaxial magnetic phase separated La{sub 1−x}Sr{sub x}CoO{sub 3} (0.07 ≤ x ≤ 0.60) thin films was studied systematically. It was found that crystalline anisotropy and spin-orbital coupling are the main contributions to the unexpected fourfold symmetric PHE. The uniaxial anisotropy field was given by H{sub uni} = 70 Oe and cubic anisotropic field H{sub cub} = 143 Oe, respectively. The magnetic anisotropy was weakened by Sr doping, which corresponds with the disappearance of the fourfold symmetry in PHE with the increasing Sr concentration. The first principle calculations proved that the contribution of Co-d orbitals to the magnetic anisotropy strongly depends on the Sr concentration. e{sub g}−d{sub x{sup 2}−y{sup 2}} and e{sub g}−d{sub 3z{sup 2}−r{sup 2}} orbitals play a dominant role in the magnetic anisotropy of the samples with x = 0.125, 0.25, while the t{sub 2g}−d{sub xy}, d{sub yz}, d{sub xz} orbitals contribute mainly to the magnetic anisotropy of the samples with x = 0.375, 0.5, 0.625.

  5. Ultraviolet laser crystallized ZnO:Al films on sapphire with high Hall mobility for simultaneous enhancement of conductivity and transparency

    SciTech Connect (OSTI)

    Nian, Qiong; Zhang, Martin Y.; Schwartz, Bradley D.; Cheng, Gary J.

    2014-05-19

    One of the most challenging issues in transparent conductive oxides (TCOs) is to improve their conductivity without compromising transparency. High conductivity in TCO films often comes from a high carrier concentration, which is detrimental to transparency due to free carrier absorption. Here we show that UV laser crystallization (UVLC) of aluminum-doped ZnO (AZO) films prepared by pulsed laser deposition on sapphire results in much higher Hall mobility, allowing relaxation of the constraints of the conductivity/transparency trade-off. X-ray diffraction patterns and morphological characterizations show grain growth and crystallinity enhancement during UVLC, resulting in less film internal imperfections. Optoelectronic measurements show that UVLC dramatically improves the electron mobility, while the carrier concentration decreases which in turn simultaneously increases conductivity and transparency. AZO films under optimized UVLC achieve the highest electron mobility of 79 cm{sup 2}/V s at a low carrier concentration of 7.9 × 10{sup +19} cm{sup −3}. This is realized by a laser crystallization induced decrease of both grain boundary density and electron trap density at grain boundaries. The infrared (IR) to mid-IR range transmittance spectrum shows UVLC significantly enhances the AZO film transparency without compromising conductivity.

  6. Public Assembly | Open Energy Information

    Open Energy Info (EERE)

    whether in private or non-private meeting halls. Sub Categories social or meeting (e.g. community center, lodge, meeting hall, convention center, senior center); recreation...

  7. Multi-Probe Diagnostic Hall

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    multiscale fluid dynamics, or extreme electromagnetic field interactions with matter. ... compression science, is vital to a broad spectrum of engineering and defense applications ...

  8. Minority carrier lifetime in mid-wavelength infrared InAs/InAsSb superlattices: Photon recycling and the role of radiative and Shockley-Read-Hall recombination mechanisms

    SciTech Connect (OSTI)

    Höglund, L.; Ting, D. Z.; Soibel, A.; Fisher, A.; Khoshakhlagh, A.; Hill, C. J.; Keo, S.; Gunapala, S. D.

    2014-11-10

    The influence of radiative recombination on the minority carrier lifetime in mid-wavelength InAs/InAsSb superlattices was investigated. From the lifetime's dependence on temperature, photon recycling, and carrier concentration, it was demonstrated that radiative lifetime dominates for carrier concentrations >5 × 10{sup 14} cm{sup −3}, and Shockley-Read-Hall recombination starts to dominate the minority carrier lifetime for carrier concentrations <5 × 10{sup 14} cm{sup −3}. An observed increase of the minority carrier lifetime with increasing superlattice thickness was attributed to photon recycling, and good agreement between measured and theoretical values of the photon recycling factor was obtained.

  9. Enhanced inverse spin Hall contribution at high microwave power levels in La{sub 0.67}Sr{sub 0.33}MnO{sub 3}/SrRuO{sub 3} epitaxial bilayers

    SciTech Connect (OSTI)

    Haidar, S. M. Lustikova, J.; Shiomi, Y.; Saitoh, E.

    2015-10-12

    We have investigated microwave power dependence of dc voltage generated upon ferromagnetic resonance in a La{sub 0.67}Sr{sub 0.33}MnO{sub 3}/SrRuO{sub 3} epitaxial bilayer film at room temperature. With increasing microwave power above ∼75 mW, the magnitude of the voltage signal decreases as the sample temperature approaches the Curie temperature of La{sub 0.67}Sr{sub 0.33}MnO{sub 3} due to heating effects. By analyzing the dependence of the voltage signal on the direction of the magnetic field, we show that with increasing microwave power the contribution from the inverse spin Hall effect becomes more dominant than that from the anisotropic magnetoresistance effect.

  10. Enhancement of perpendicular magnetic anisotropy and transmission of spin-Hall-effect-induced spin currents by a Hf spacer layer in W/Hf/CoFeB/MgO layer structures

    SciTech Connect (OSTI)

    Pai, Chi-Feng; Nguyen, Minh-Hai; Vilela-Leão, Luis Henrique; Buhrman, R. A.; Belvin, Carina; Ralph, D. C.

    2014-02-24

    We report that strong perpendicular magnetic anisotropy of the ferromagnetic layer in a W/CoFeB/MgO multilayer structure can be established by inserting a Hf layer as thin as 0.25 nm between the W and CoFeB layers. The Hf spacer also allows transmission of spin currents generated by an in-plane charge current in the W layer to apply strong spin torque on the CoFeB, thereby enabling current-driven magnetic switching. The antidamping-like and field-like components of the spin torque exerted on a 1 nm CoFeB layer are of comparable magnitudes in this geometry. Both components originate from the spin Hall effect in the underlying W layer.

  11. Increase in the Shockley–Read–Hall recombination rate in InGaN/GaN QWs as the main mechanism of the efficiency droop in LEDs at high injection levels

    SciTech Connect (OSTI)

    Bochkareva, N. I.; Rebane, Yu. T.; Shreter, Yu. G.

    2015-12-15

    It is shown that the efficiency droop observed as the current through a GaN-based light-emitting diode increases is due to a decrease in the Shockley–Read–Hall nonradiative lifetime. The lifetime decreases with increasing current because a steadily growing number of traps in the density-of-states tails of InGaN/GaN quantum wells become nonradiative recombination centers upon the approach of quasi-Fermi levels to the band edges. This follows from the correlation between the efficiency droop and the appearance of negative differential capacitance, observed in the study. The correlation appears due to slow trap recharging via the trap-assisted tunneling of electrons through the n-type barrier of the quantum well and to the inductive nature of the diode-current variation with forward bias.

  12. Fire Water Lodge Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Lodge Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Fire Water Lodge Pool & Spa Low Temperature Geothermal Facility Facility Fire Water Lodge...

  13. Notaras Lodge Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Notaras Lodge Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Notaras Lodge Pool & Spa Low Temperature Geothermal Facility Facility Notaras Lodge...

  14. Sawtooth Lodge Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Sawtooth Lodge Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Sawtooth Lodge Pool & Spa Low Temperature Geothermal Facility Facility Sawtooth Lodge...

  15. Influence of Ga content on the structure and anomalous Hall effect of Fe{sub 1−x}Ga{sub x} thin films on GaSb(100)

    SciTech Connect (OSTI)

    Anh Tuan, Duong; Shin, Yooleemi; Viet Cuong, Tran; Cho, Sunglae; Phan, The-Long

    2014-05-07

    The Fe{sub 1−x}Ga{sub x} thin films (x = 0.4, 0.5) have been grown on GaSb(100) substrate using molecular beam epitaxy. An epitaxial film with bcc α-Fe crystal structure (A2) is observed in Fe{sub 0.6}Ga{sub 0.4} film, while an impure Fe{sub 3}Ga phase with DO{sub 3} structure is appeared in Fe{sub 0.5}Ga{sub 0.5} film. The saturated magnetizations at room temperature are observed to be 570 emu/cm{sup 3} and 180 emu/cm{sup 3} and the coercivities to be 170 and 364 Oe for Fe{sub 0.6}Ga{sub 0.4} and Fe{sub 0.5}Ga{sub 0.5}, respectively. A hysteresis trend in Hall resistance vs. magnetic field is observed for Fe{sub 0.5}Ga{sub 0.5} film. However, there is a weak hysteresis noticed in Fe{sub 0.4}Ga{sub 0.6} thin film.

  16. Hall effect measurements on thermoelectric Ca{sub 3}Co{sub 4}O{sub 9}: On how to determine the charge carrier concentration in strongly correlated misfit cobaltites

    SciTech Connect (OSTI)

    Schrade, Matthias; Norby, Truls; Finstad, Terje G.

    2015-05-28

    The Hall coefficient R{sub H} and electrical conductivity of misfit calcium cobalt oxide (Ca{sub 2}CoO{sub 3−δ}){sub q}(CoO{sub 2}) (CCO) were measured at room temperature for different oxygen vacancy concentrations δ. Based on these and numerous previous results, it is shown that the charge carrier concentrations n obtained by the classical formula R{sub H} = 1/ne are between 3 and 6 × 10{sup 20} cm{sup −3} and thereby much lower than those derived by other experimental techniques and fail to explain the observed electric properties of CCO. We show that the experimental results are well described using an earlier proposed t–J-model for strongly correlated electrons on a triangular lattice. The hopping parameter t for CCO was found to be ≈ −20 K and the charge carrier concentration of fully oxidized CCO to be 5.7 × 10{sup 21} cm{sup −3} (0.41 hole type carriers per formula unit), in agreement with other experimental techniques.

  17. Airports & Lodging | Savannah River Ecology Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Airports and Lodging AIRPORTS Augusta, GA Augusta Regional Airport (Bush Field) - closest commercial airport; Delta and U.S. Express. Daniel Field - private planes, rentals, or chartered flights. Columbia, SC Columbia Metropolitan Airport - all major carriers; 1.5-2h drive to SREL. Atlanta, GA Hartsfield Airport - all major carriers; 2.5-3 hour drive from Atlanta, GA, to Aiken, SC. LODGING No lodging is available at SREL. However, hotels and motels are available in Aiken, SC, and Augusta, GA.

  18. Glenwood Hot Springs Lodge Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Lodge Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Glenwood Hot Springs Lodge Space Heating Low Temperature Geothermal Facility Facility...

  19. Fermilab | Tevatron | Tevatron Symposium | Travel and Lodging

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Travel and Lodging Directions to Fermilab Local Accommodations Map of Local Hotels Transportation Visa Information Wifi Access at Fermilab Other Useful Links

  20. Town Hall Meeting | OpenEI Community

    Open Energy Info (EERE)

    introductions - name, company, potential icebreaker (what's your favorite analysis tool, programming language, energy sector..) 5 minutes OpenEI: what's new and coming soon 5...

  1. The Honorable,Edward Rendell, '. City Hall

    Office of Legacy Management (LM)

    W.,Alexander Williams (301-427-17i9) of my staff. i ' . Enclosures ,, Director Off-SiteSavannah River Division 'Office of Eastern Areas Programs. Office of Environmental ...

  2. The Honorable Edward Rendell City Hall

    Office of Legacy Management (LM)

    W. Alexander Williams (301-427-1719) of my staff. ), Enclosures, James W. Wagoner II Director ,. : Off-Sit.eSavannah River Division Office of Eastern Area,Programs I Office of ...

  3. User-Program_Town_Hall-11.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    representative on the UEC. Nominations were accepted from the floor as follows: * Rafael Verduzco nominated by Marco Nardelli for at---large member, and seconded b y M artyn M...

  4. Spin Hall effects in metallic antiferromagnets - perspectives...

    Office of Scientific and Technical Information (OSTI)

    60439, USA, Department of Physics and Astronomy, Northwestern University, Evanston IL ... IL 60616, USA Department of Physics and Astronomy, Northwestern University, Evanston IL ...

  5. National Energy Literacy Virtual Town Hall

    Broader source: Energy.gov [DOE]

    The webinar will be a dynamic, virtual conversation for educators about ongoing efforts from across the country in utilizing the Department of Energy's Energy Literacy Framework to address one of our nation's’ biggest national challenges, energy illiteracy.

  6. Deck Those Halls! | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    of Energy The Department issued a Contractor Requirements Document (CRD) for the subject Directive on February 19, 2013. PF2013-33 Department of Energy Order 206.2 Identity, Credential, and Access Management (ICAM) (16.32 KB) PF2013-33a.pdf (60.07 KB) More Documents & Publications Status IT Reporting Format and Requirements for the BY 2017 Budget Submission FY18 Agency IT Portfolio Summary Guidance

    To set forth requirements and responsibilities for creating and preserving records

  7. NUG_TownHall_Oct2009.ppt

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (memory, IO, CPU hours) * How easy is it for you to translate your science and research objectives into quantitative computational requirements? - Which is the hardest...

  8. Temperature-driven band inversion in Pb0.77Sn0.23Se: Optical and Hall effect studies

    SciTech Connect (OSTI)

    Anand, Naween; Buvaev, Sanal; Hebard, A. F.; Tanner, D. B.; Chen, Zhiguo; Li, Zhiqiang; Choudhary, Kamal; Sinnott, S. B.; Gu, Genda; Martin, C.

    2014-12-23

    Optical and Hall-effect measurements have been performed on single crystals of Pb₀.₇₇Sn₀.₂₃Se, a IV-VI mixed chalcogenide. The temperature dependent (10–300 K) reflectance was measured over 40–7000 cm⁻¹ (5–870 meV) with an extension to 15,500 cm⁻¹ (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy optical spectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Thus, density function theory calculation for the electronic band structure also make similar predictions.

  9. Minto Upgrades Community Lodge with START Support | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Minto Upgrades Community Lodge with START Support Minto Upgrades Community Lodge with START Support October 20, 2014 - 5:00pm Addthis With DOE support, workers weatherize the exterior of the Lakeview Lodge in Minto, Alaska. Photo from Russell Snyder, Interior Regional Housing Authority, NREL 31796 With DOE support, workers weatherize the exterior of the Lakeview Lodge in Minto, Alaska. Photo from Russell Snyder, Interior Regional Housing Authority, NREL 31796 The Lakeview Lodge is the heart of

  10. Jackson Hot Springs Lodge Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Jackson Hot Springs Lodge Space Heating Low Temperature Geothermal Facility Facility Jackson...

  11. The Wilderness Lodge Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name The Wilderness Lodge Space Heating Low Temperature Geothermal Facility Facility The Wilderness...

  12. The Wilderness Lodge Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Low Temperature Geothermal Facility Facility The Wilderness Lodge Sector Geothermal energy Type Pool and Spa Location Silver City, New Mexico Coordinates 32.770075,...

  13. Sierra Grande Lodge Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Spa Low Temperature Geothermal Facility Facility Sierra Grande Lodge Sector Geothermal energy Type Pool and Spa Location Truth or Consequences, New Mexico Coordinates 33.1284047,...

  14. Off-site Lodging (short-term) | Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Off-site Lodging (short-term): Extended Stay America external link 2345 Sokol Court, Darien, IL (For special Argonne rates call 630-985-4708) Oakwood Apartments external link...

  15. DOE - Office of Legacy Management -- Lodge and Shipley - OH 24

    Office of Legacy Management (LM)

    Lodge and Shipley - OH 24 FUSRAP Considered Sites Site: LODGE AND SHIPLEY (OH.24 ) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Cincinnati , Ohio OH.24-1 Evaluation Year: 1987 OH.24-1 Site Operations: Research, Development and Testing involving small quantities of Uranium metal(property of the AEC). OH.24-1 OH.24-3 Site Disposition: Eliminated - Limited scope of activities performed - Potential for residual radioactive

  16. Building America Top Innovations Hall of Fame Profile … Tankless...

    Energy Savers [EERE]

    water heaters was one of many energy-efficiency recommendations Building America's research team IBACOS had for San Antonio builder Imagine Homes. Although tankless gas water ...

  17. Edge State Induced Andreev Oscillation in Quantum Anomalous Hall...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  18. Quantum Anomalous Hall Effect in 2D Organic Topological Insulators...

    Office of Scientific and Technical Information (OSTI)

    Publisher: American Physical Society Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud More Like This Free Publicly Accessible Full Text ...

  19. Building America Top Innovations Hall of Fame Profile … Integration...

    Energy Savers [EERE]

    worked with S&A Homes to design a compact HVAC layout with all ducts in conditioned space in several homes in Pittsburgh. Poor-quality HVAC design and installation can reduce ...

  20. Engineering quantum anomalous/valley Hall states in graphene...

    Office of Scientific and Technical Information (OSTI)

    Publication Date: 2011-11-15 OSTI Identifier: 1101181 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 84; ...

  1. Effective field theory of fractional quantized Hall nematics...

    Office of Scientific and Technical Information (OSTI)

    Publication Date: 2011-11-28 OSTI Identifier: 1101247 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 84; ...

  2. Building America Top Innovations Hall of Fame Profile ? Moisture...

    Energy Savers [EERE]

    shared the lessons learned in manufactured housing with site builders including Tommy Williams Homes of Gainesville, Florida, who implemented measures like mastic sealing ducts,...

  3. Building America Top Innovations Hall of Fame Profile … Zero...

    Energy Savers [EERE]

    Four California home builders who worked with Building America to incorporate energy ... This project, Vista Montana, in Watsonville, California, was the largest near zero energy ...

  4. Building America Top Innovations Hall of Fame Profile ? Reduced...

    Energy Savers [EERE]

    linkage between high- performance homes and reduced call-backs, with builders reporting big reductions in call-backs since the program began in 1995. Although few builders are...

  5. Building America Top Innovations Hall of Fame Profile … Outside...

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    Outside Air Ventilation Controller Building America researchers developed technologies to ... reduce, delay, or completely eliminate air conditioner operation resulting in both ...

  6. Building America Top Innovations Hall of Fame Profile … Attic...

    Energy Savers [EERE]

    Terminology Air Barrier Material (ABM) --- A does not allow air to pass throu plywoodOSB, foam board, duc lumber. Backing --- Any material that s be sprayed so as to provide an ...

  7. Building America Top Innovations Hall of Fame Profile … Thermal...

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    the importance of thermal bypass air barriers, which led to their inclusion in ... Air sealing of the home's thermal enclosure has been required by the energy code for many ...

  8. Spin-Hall-assisted magnetic random access memory (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    OSTI Identifier: 22257135 Resource Type: Journal Article Resource Relation: Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 1; Other Information: (c) ...

  9. Observation of the Integer Quantum Hall Effect in Record High...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: DE-AC04-94AL85000 Resource Type: Journal Article Resource Relation: Journal Name: Applied Physics Letters; Related Information: Proposed for publication in ...

  10. Building America Top Innovations Hall of Fame Profile … Low...

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    fan as the only form of mechanical ventilation in the home. Building America research has shown this is the lowest-cost approach that can meet ASHRAE 62.2 ventilation requirements. ...

  11. Building America Top Innovations Hall of Fame Profile … Building...

    Energy Savers [EERE]

    Air-Conditioning Engineers (ASHRAE) and the International Energy Conservation Code (IECC) for their residential and commercial building standards. ASHRAE used 38 climate groupings ...

  12. Building America Top Innovations Hall of Fame Profile … Vapor...

    Energy Savers [EERE]

    In an article published in the ASHRAE Journal August 2004, Building Science Corporation's ... In the ASHRAE paper, Lstiburek provided a detailed proposal for building code requirements ...

  13. Building America Top Innovations Hall of Fame Profile … High...

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    typical cold climate wall assemblies modeled at ASHRAE 160 interior conditions (SWA 2012). ... Nearly every wall in this study failed the ASHRAE 160 30-day criteria, with interior ...

  14. Building America Top Innovations Hall of Fame Profile … Basement...

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    When cellulose or fiberglass insulation is installed in contact with basement walls, it ... BSC. 2009. "Basement Insulation." Info- 511, Building Science Corporation. www. ...

  15. Probing the thermal Hall effect using miniature capacitive strontium...

    Office of Scientific and Technical Information (OSTI)

    Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA Department of Physics, University of California, Berkeley, California 94720, USA Publication Date: ...

  16. Building America Top Innovations Hall of Fame Profile … High...

    Energy Savers [EERE]

    Each home achieved a Home Energy Rating Score (HERS) of 70 or better while ensuring the resulting utility bill savings ... a 0.92 energy factor (EF) electric tank hot water heater, ...

  17. Hypernuclear Spectroscopy at JLab Hall C (Conference) | SciTech...

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    Ed ; Ent, Rolf ; Fenker, Howard ; Gaskell, David ; Horn, Tanja ; Jones, Mark ; Smith, Gregory ; Vulcan, William ; Wood, Stephen ; Johnston, C ; Simicevic, Neven ; Wells, ...

  18. Hypernuclear spectroscopy program at JLab Hall C (Journal Article...

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    Victor ; Sato, Yoshinori ; Seva, Tomislav ; Tang, Liguang ; Simicevic, Neven ; Smith, Gregory ; Sumihama, Mizuki ; Song, Y. ; Tadevosyan, Vardan ; Takahashi, Toshiyuki ; ...

  19. The Honorable'George Kubin City Hall Dear Mayor Kubin:

    Office of Legacy Management (LM)

    W; Alexander Williams ' (301-427-1719) of my staff,. I '. Sincerely. n-l James W. Wagoner II r' Director ' .' Off-SiteSavannah River Program Division Office of Eastern Area ...

  20. Town Hall Slides_6_19_14.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Three main options under consideration: 1. VJT tool using 2" titanium rods 2. Gantry camera 3. Existing process (pole and camera) VJT tool with titanium rods - Option 1 VJT tool ...

  1. Fractional quantum spin Hall effect in flat-band checkerboard...

    Office of Scientific and Technical Information (OSTI)

    GrantContract Number: FG02-06ER46305 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 90; Journal Issue: 8; ...

  2. Town_Hall_Slides_5_22_14.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    22, 2014 Meeting Agenda * Opening Comments - Mayor Dale Janway * Panel Member Introductions - John Heaton (Moderator) * CBFO Manager Remarks - Joe Franco * Update on Phase 3 ...

  3. Town_Hall_Slides_5_8_14

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    * Opening Comments - Mayor Janway * Panel Member Introductions - John Heaton ... will also collect additional samples from Panel 7 to help with the forensic analysis ...

  4. Effective Field Theory of Fractional Quantized Hall Nematics...

    Office of Scientific and Technical Information (OSTI)

    We interpret recent experiments at Landau level filling factor nu 73 in terms of our theory. Authors: Mulligan, Michael ; MIT, LNS ; Nayak, Chetan ; Station Q, UCSB ; ...

  5. Reduced spin-Hall effects from magnetic proximity (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Authors: Zhang, Wei ; Jungfleisch, Matthias B. ; Jiang, Wanjun ; Liu, Yaohua ; Pearson, John E. ; Velthuis, Suzanne G. E. te ; Hoffmann, Axel ; Freimuth, Frank ; Mokrousov,...

  6. Building America Top Innovations Hall of Fame Profile … Building...

    Energy Savers [EERE]

    There are many energy analysis software tools out there-some do optimization, some do ... Moreover, many BEopt algorithms have been adopted by private-sector HERS software tools ...

  7. Building America Top Innovations Hall of Fame Profile … National...

    Energy Savers [EERE]

    The data are available for use in software programs that evaluate cost-effective measures ... technical consistency and accuracy of software program results. * Enables experts and ...

  8. Building America Top Innovations Hall of Fame Profile … Unvented...

    Energy Savers [EERE]

    demonstrated 15% to 18% less energy consumption for heating and cooling while reducing ... of the International Residential Code (R408.3) allowing unvented, conditioned crawlspaces. ...

  9. Building America Top Innovations Hall of Fame Profile … High...

    Energy Savers [EERE]

    ... Each home's 2.2-kW photovoltaic system produced about 3,330 kWh during the 12 months studied, about half the average consumption of each household (7,007 kWh). Premier Homes chose ...

  10. President Obama Talks Clean Energy At Facebook Town Hall | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    and the purpose and impact of the 2009 Recovery Act: "We made the largest investment in history in clean energy research, and it's really paying off. For example, when I came...

  11. Building America Top Innovations Hall of Fame Profile … Advanced...

    Energy Savers [EERE]

    demonstrated their compelling cost and energy savings. ... by 1,634 feet and cut costs by 171. When other ... program was started in 1995 to provide research and ...

  12. Microscopic theory of quantum anomalous Hall effect in graphene...

    Office of Scientific and Technical Information (OSTI)

    American Physical Society Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud More Like This Free Publicly Accessible Full Text Accepted...

  13. Quantum Anomalous Hall Effect in 2D Organic Topological Insulators...

    Office of Scientific and Technical Information (OSTI)

    American Physical Society Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud More Like This Free Publicly Accessible Full Text Accepted...

  14. Spin Hall Effects in Metallic Antiferromagnets (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    American Physical Society Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud More Like This Free Publicly Accessible Full Text Accepted...

  15. Building America Top Innovations Hall of Fame Profile … Ducts...

    Energy Savers [EERE]

    to put ducts in conditioned space, a technique that saves energy and improves indoor air quality. Moving ductwork into the home's conditioned space can save 8%-15% on homeowner ...

  16. Town Hall Slides 3_27_14.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    March 27, 2014 AGENDA ITEMS Joe Franco CBFO Manager Meeting Agenda * WIPP Status presentations * Tammy Reynolds * Fran Williams * Joe Franco * Audience Questions * One question at a time please * Final Remarks / Close WIPP RECOVERY PLAN ACTIVITIES Tammy Reynolds NWP Recovery Manager WIPP Recovery Plan Activities * Install a Continuous Air Monitor (CAM) at Station B * Provides real time radiological information on exhaust stack air * Installation to complete this week * One week run time to

  17. Town Hall Slides 4-10-14 FINAL.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    0, 2014 Meeting Agenda *! Opening Comments - Mayor Janway *! Update on Entries, Additional Recovery Items - Dana Bryson, Tammy Reynolds *! Environmental Sampling - Stewart Jones *! Environmental Protection Agency *! Worth Noting - Dana Bryson *! Shipments to Waste Control Specialists *! Audience Questions *! One question at a time please UPDATE ON ENTRIES Dana Bryson, CBFO Deputy Manager Tammy Reynolds, NWP Deputy Recovery Manager Re-Entry Phase 1 Phase 2A Phase 2B Phase 3 *! Unmanned Entry *!

  18. Town_Hall_Slides_1_7_16.pdf

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  19. Town_Hall_Slides_2_5_15.pdf

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  20. Town_Hall_Slides_4_2_15.pdf

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

  1. JLab, Physics Community Mourns Death of Jean Mougey, First Hall...

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    Lab, and a director of the Nuclear Physics Division at CEA Saclay, passed away from a heart attack on Nov. 5, 2015, in Grenoble. Jean was born in the French town of Angers, by...

  2. Building America Top Innovations Hall of Fame Profile … Community...

    Energy Savers [EERE]

    ... had at Civano with failed solar water-heating systems: 1) choose a solar thermal collector with single, not ... and 6) do not use continuous hot-water recirculation systems. ...

  3. Microsoft Word - UEC Town_Hall_Meeting_notes.docx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    * John Lange, Legislative Assistant to Congressman Robert Hurt, 5th District VA * Xan Fishman, Legislative Assistant to Congressman John Delany, 6th District MD * Erika Appel,...

  4. Source and Extraction for Simultaneous Four-hall Beam Delivery...

    Office of Scientific and Technical Information (OSTI)

    repetition rate for its beams, and addition of a fourth laser at the photo-cathode gun. ... The change to the beam repetition rate will be at the photo-cathode gun through an ...

  5. Hall effect in quantum critical charge-cluster glass (Journal...

    Office of Scientific and Technical Information (OSTI)

    Upon doping, cuprates undergo a quantum phase transition from an insulator to a d-wave superconductor. The nature of this transition and of the insulating state is vividly debated. ...

  6. Building America Top Innovations Hall of Fame Profile … House...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    The U.S. Department of Energy's Building America program was started in 1995 to provide ... As a national center for world-class research, Building America funds integrated research ...

  7. Building America Top Innovations Hall of Fame Profile … Building...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Innovations sponsored by the U.S. Department of Energy's (DOE's) Building America program ... DOE established the Building America program in 1995 to address both the huge ...

  8. Missed the Town Hall with Secretary Chu? | Department of Energy

    Office of Environmental Management (EM)

    one million advanced technology vehicles on the road by 2015; A "Sun Shot" initiative to make solar energy cost-competitive with fossil-based fuels before the end of this ...

  9. Microsoft Word - Town-Hall-meeting_notes_090215.docx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    State Brian Long-U. Tennessee Yayoi Takamura-University of California, Davis Yang Zhang-U. Illinois (possibly Secretary) Milan Buncick- AEgis Technologies Vice Chair:...

  10. A two fluid description of the Quantum Hall Soliton (Journal...

    Office of Scientific and Technical Information (OSTI)

    Research Org: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States) Sponsoring Org: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25) Country of ...

  11. Hall C Safety Awareness Training Updated | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Solar Energy | Department of Energy Halfway There But Far From Done: SunShot Surges Ahead on Path to Affordable Solar Energy Halfway There But Far From Done: SunShot Surges Ahead on Path to Affordable Solar Energy May 18, 2016 - 10:35am Addthis Halfway There But Far From Done: SunShot Surges Ahead on Path to Affordable Solar Energy What are the key facts? The SunShot Initiative has grown significantly in the last five years and is 70% of the way toward its goal to make solar fully

  12. Microsoft Word - Town-Hall-meeting_2014.docx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (LSPR) spectroscopy Jilai Ding Georgia Institute of Technology Poster 28, Study of Ionic Dynamics in Nanostructured Ceria through Lateral Electrochemical Measurements and Finite...

  13. Rebuilding It Better: Greensburg, Kansas, City Hall | Open Energy...

    Open Energy Info (EERE)

    *Other commercial and public buildings will be designed to LEED Platinum or Gold rating levels *100% renewable electricity 100% of the time Reduce GHG emissions by 36%...

  14. Spin Hall Effects in Metallic Antiferromagnets (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Publisher: American Physical Society Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud More Like This Free Publicly Accessible Full Text ...

  15. Effective Field Theory of Fractional Quantized Hall Nematics...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  16. New JLab/Hall A Deeply Virtual Compton Scattering results

    SciTech Connect (OSTI)

    Defurne, Maxime

    2015-08-01

    New data points for unpolarized Deeply Virtual Compton Scattering cross sections have been extracted from the E00-110 experiment at Q2=1.9 GeV2 effectively doubling the statistics available in the valence region. A careful study of systematic uncertainties has been performed.

  17. Building America Top Innovations Hall of Fame Profile ? Unvented...

    Energy Savers [EERE]

    can often have a dew point that is higher than the interior crawlspace framing surface temperature. As evidence, existing vented crawlspaces have experienced serious moisture...

  18. Quantum Hall ice (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Authors: Chern, Gia-Wei ; Rahmani, Armin ; Martin, Ivar ; Batista, Cristian D. Publication Date: 2014-12-01 OSTI Identifier: 1181136 GrantContract Number: LANLLDRD Type: ...

  19. Building America Top Innovations Hall of Fame Profile … Affordable...

    Energy Savers [EERE]

    affordable, high-performance homes in New Mexico and Colorado with HERS scores of 0 to ... The builder also sold another 18 homes under its "solar 30" plan that brought the HERS ...

  20. Secretary Moniz Leads DOE Town Hall | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Secretary Moniz and Deputy Secretary Poneman address questions from Department of Energy ... Secretary Moniz: Week One Watch the swearing-in ceremony. See a video recap of Secretary ...

  1. Town Hall Slides 9.4.14 FINAL.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    * Recovery Planning Activities - Tammy Reynolds * Closing Comments - Dana Bryson * Audience Questions * One question at a time please RECOVERY UPDATE Dana Bryson, Deputy...

  2. Controlling the Plasma Flow in the Miniaturized Cylindrical Hall Thruster

    SciTech Connect (OSTI)

    A. Smirnov, Y. Raitses and N.J. Fisch

    2008-03-04

    A substantial narrowmg of the plume of the cylindrical RaIl thruster (CRT) was observed upon the enhancement of the electron emission from the hollow cathode discharge, which implies the possibility for the thruster efficiency increase due to the ion beam focusing. It is demonstrated that the miniaturized CRT can be operated in the non-self-sustained regime, with the discharge current limited by the cathode electron emission. The thruster operation in this mode greatly expands the range of the plasma and discharge parameters normally accessible for the CRT.

  3. Building America Top Innovations Hall of Fame Profile … Unvented...

    Energy Savers [EERE]

    ... * Disaster Resistance - Roofs over unvented attics are ... rain and better protects metal connectors in the roof ... roof deck (to keep its temperature above 45F throughout ...

  4. Diversity Town Hall Draws a Crowd at the Energy Department

    Broader source: Energy.gov [DOE]

    “For our own good, we want as wide of a talent pool as we can get,” Secretary Steven Chu said in his remarks to employees. “[Diversity] is a good thing and an important thing to do. It’s also the right thing to do.”

  5. Building America Top Innovations Hall of Fame Profile ? ENERGY...

    Energy Savers [EERE]

    worked with Building America to build all 290 units at its Cobblefield development to ENERGY STAR criteria. The builder was one of several featured in a series of guides...

  6. Town Hall Meeting #3: Green Button | OpenEI Community

    Open Energy Info (EERE)

    You must login in order to post into this group. Latest blog post comments Mike o spectacular dataset Posted: 9 Aug 2015 - 14:46 by: Mike o Calum Residential idf Files Posted:...

  7. Earth Week event all about energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Earth Week event all about energy Earth Week event all about energy People all across ... Energy Town Hall is April 21 at Fuller Lodge LOS ALAMOS, New Mexico, April 16, 2009-People ...

  8. April Events

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Thu 5:30 PM Accident Investigation Board (AIB) findings about the drum breach at WIPP Fuller Lodge - 2132 Central Avenue, Los Alamos The Department of Energy will host a town hall...

  9. Technical Support Document: 50% Energy Savings Design Technology Packages for Highway Lodging Buildings

    SciTech Connect (OSTI)

    Jiang, Wei; Gowri, Krishnan; Lane, Michael D.; Thornton, Brian A.; Rosenberg, Michael I.; Liu, Bing

    2009-09-28

    This Technical Support Document (TSD) describes the process, methodology and assumptions for development of the 50% Energy Savings Design Technology Packages for Highway Lodging Buildings, a design guidance document intended to provide recommendations for achieving 50% energy savings in highway lodging properties over the energy-efficiency levels contained in ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings.

  10. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Week event all about energy April 16, 2009 Energy Town Hall is April 21 at Fuller Lodge LOS ALAMOS, New Mexico, April 16, 2009-People all across Northern New Mexico can learn about how they can play a role in energy research and energy and fuel conservation at an upcoming Energy Town Hall in Los Alamos. Other issues related to energy on the Pajarito Plateau, such as renewable energy and energy technologies, planning, programs, and goals also will be discussed. The Town Hall is from 8:30 a.m. to

  11. February 25, 2015 in 100E Hildebrand Hall starts at 11:45am ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Previous Next List Anne Marti (National Energy Technology Laboratory) Metal Organic Framework Development for CO2 Selective Mixed Matrix Membranes Kyriakos Stylianou (EPFL, ...

  12. June 25, 2014 in 100D Hildebrand Hall | Center for Gas SeparationsRele...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bess Vlaisavljevich (Dept. of Chemical and Biomolecular Engineering, UC Berkeley) Adsorption Mechanism of CO2 in mmen-Mg2(dobpdc), an Amine Functionalized Metal Organic Framework ...

  13. February 26, 2014 in 100E Hildebrand Hall | Center for GasSeparations...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Networks for CO2 Capture Walter Drisdell (Materials Sciences Division, LBNL) Investigating CO2 Adsorption in an Amine-Appended Metal-Organic Framework using NEXAFS Spectroscopy

  14. Town Hall Meeting July 23th, 2012 | OpenEI Community

    Open Energy Info (EERE)

    introductions - name, company, potential icebreaker (what's your favorite analysis tool, programming language, energy sector..) Topic will be user feedback on OpenEI. Please join...

  15. Town Hall Meeting August 6th, 2012 | OpenEI Community

    Open Energy Info (EERE)

    introductions - name, company, potential icebreaker (what's your favorite analysis tool, programming language, energy sector..) Topic will be geothermal related with Geothermal...

  16. Town Hall Meeting July 9th, 2012 | OpenEI Community

    Open Energy Info (EERE)

    introductions - name, company, potential icebreaker (what's your favorite analysis tool, programming language, energy sector..) Topic focus for July 9: Discussion of utility rates...

  17. January 22, 2014 in 100E Hildebrand Hall | Center for GasSeparationsR...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Previous Next List Miguel Gonzalez (Dept. of Chemistry, UC Berkeley) Designing Metal-Organic Frameworks for Catalysis Richard Martin (Computational Research Division, LBNL) Advances ...

  18. Berry phase mechanism of the anomalous Hall effect in a disordered...

    Office of Scientific and Technical Information (OSTI)

    interactions and ferromagnetic order and is a potentially useful probe of electron spin polarization, especially in nanoscale systems where direct measurement is not feasible. ...

  19. Disorder Matters in the 5/2 Fractional Quantum Hall Effect (invited...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  20. Building America Top Innovations Hall of Fame Profile – Building Energy Optimization Analysis Method (BEopt)

    Broader source: Energy.gov [DOE]

    This Building America Innovations profile describes the DOE-sponsored BEopt software, which ensures a consistent analysis platform and accurate simulations. Many BEopt algorithms have been adopted by private-sector HERS software tools that have helped improve the energy efficiency of tens-of-thousands of ENERGY STAR-certified homes.

  1. Material Activation Benchmark Experiments at the NuMI Hadron Absorber Hall in Fermilab

    SciTech Connect (OSTI)

    Matsumura, H.; Matsuda, N.; Kasugai, Y.; Toyoda, A.; Yashima, H.; Sekimoto, S.; Iwase, H.; Oishi, K.; Sakamoto, Y.; Nakashima, H.; Leveling, A.; Boehnlein, D.; Lauten, G.; Mokhov, N.; Vaziri, K.

    2014-06-15

    In our previous study, double and mirror symmetric activation peaks found for Al and Au arranged spatially on the back of the Hadron absorber of the NuMI beamline in Fermilab were considerably higher than those expected purely from muon-induced reactions. From material activation bench-mark experiments, we conclude that this activation is due to hadrons with energy greater than 3 GeV that had passed downstream through small gaps in the hadron absorber.

  2. Tunable Anderson metal-insulator transition in quantum spin-Hall...

    Office of Scientific and Technical Information (OSTI)

    GrantContract Number: FG02-99ER45747 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 91; Journal Issue: 21; ...

  3. EECBG Success Story: After 105 Years, Historic City Hall in West...

    Broader source: Energy.gov (indexed) [DOE]

    the installation of four geothermal heating wells, a rooftop covered with vegetation, solar panels and permeable pavers to allow stormwater through to the soil below. Learn more. ...

  4. Competing Quantum Hall Phases in the Second Landau Level in Low...

    Office of Scientific and Technical Information (OSTI)

    Number: AC04-94AL85000 Resource Type: Journal Article Resource Relation: Journal Name: Physical Review Letters; Related Information: Proposed for publication in Physical Review...

  5. Quantum anomalous Hall effect in single-layer and bilayer graphene...

    Office of Scientific and Technical Information (OSTI)

    B Additional Journal Information: Journal Volume: 83; Journal Issue: 15; Journal ID: ISSN 1098-0121 Publisher: American Physical Society Sponsoring Org: USDOE Country of...

  6. Inverse spin Hall effect in Pt/(Ga,Mn)As (Journal Article) |...

    Office of Scientific and Technical Information (OSTI)

    H. ; Matsukura, F., E-mail: f-matsu@wpi-aimr.tohoku.ac.jp 1 ; WPI-Advanced Institute for Materials Research 4 ; Center for Spintronics Integrated Systems, Tohoku University, ...

  7. Non-abelian fractional quantum hall effect for fault-resistant...

    Office of Scientific and Technical Information (OSTI)

    Authors: Pan, Wei ; Thalakulam, Madhu ; Shi, Xiaoyan ; Crawford, Matthew ; Nielsen, Erik ; Cederberg, Jeffrey George Publication Date: 2013-10-01 OSTI Identifier: 1121903 Report ...

  8. Spin pumping and inverse spin Hall effects-Insights for future...

    Office of Scientific and Technical Information (OSTI)

    in Ir and W using the conventional bilayer structures and discuss the self-induced voltage in a single layer of ferromagnetic permalloy. Finally, we extend our discussions to...

  9. Dr. Smith Goes to Washington: A Physicist Wanders the Halls of Congress

    SciTech Connect (OSTI)

    Tannenbaum, Benn

    2005-03-23

    Dr. Tannenbaum was the 2002-2003 APS Congressional Science Fellow. He worked in the office of U.S. Rep. Edward Markey (D-MA) on nuclear nonproliferation issues. His work in Congressman Markey's office focused on issues including missile defense, the nuclear program in Iran, prevention of the transfer of U.S. nuclear technology to North Korea, and the security of nuclear sites in Iraq. Dr. Tannenbaum will discuss this experience and observations concerning 'underinformed and uninformed' decision-making in Congress. He will also briefly discuss goals of the Center for Science, Technology and Security Policy at the American Association for the Advancement of Science. Finally, he will discuss ways in which physicists can get more involved in the political process.

  10. Microsoft PowerPoint - Town Hall Slides 4_3_14

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    April 03, 2014 AGENDA ITEMS Joe Franco CBFO Manager Meeting Agenda * Opening Comments - Mayor Janway * Overview of Underground Entry - Tammy Reynolds * Recovery Next Steps - Tammy Reynolds / Joe Franco * Waste Control Specialists (WCS) Contract and LANL Shipment Status - Bob McQuinn * Worth Mentioning - Joe Franco * WIPPTREX * Accident Investigation Board Report Status * Looking Ahead * Audience Questions * One question at a time please * Final Remarks / Close WIPP RECOVERY PLAN ACTIVITIES Joe

  11. Microsoft PowerPoint - Town Hall Slides 5-29-14

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    29, 2014 Meeting Agenda * Opening Comments - Mayor Janway * Introductions / Guidelines - Carrie Meyer (Moderator) * CBFO Deputy Manager Remarks - Dana Bryson * Update on Recovery Activities - Tammy Reynolds * Audience Questions * One question at a time please OPENING COMMENTS Dana Bryson, CBFO Deputy Manager UPDATE ON RECOVERY ACTIVITIES Tammy Reynolds, NWP Deputy Recovery Manager Event Investigation Continues - May 22 Entry * We have identified one breached drum * The drum was confirmed as

  12. Microsoft PowerPoint - Town Hall Slides 6-05-14 rev. 2

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    June 5, 2014 Meeting Agenda * Opening Comments - Mayor Janway * Introductions / Guidelines - Ben Williams (Moderator) * Overview of Week's Activities - Joe Franco * Update on Recovery Activities - Tammy Reynolds * Audience Questions * One question at a time please OPENING COMMENTS Joe Franco, CBFO Manager Overview of Week's Activities * May 30 th entry into the underground * Obtained samples for testing * Last entry into underground until filter change-out is complete * Filter change-out *

  13. Microsoft PowerPoint - Town Hall Slides 7-10-14 rev 0

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    July 10, 2014 Meeting Agenda * Opening Comments - Mayor Janway * Introductions / Guidelines - Donavan Mager (Moderator) * Overview of Recovery Activities - Joe Franco * Recovery Update - Tammy Reynolds * Audience Questions * One question at a time please OVERVIEW OF RECOVERY ACTIVITIES Joe Franco, CBFO Manager Overview of Week's Activities * Finalizing recovery plan - next steps * Accident Investigation Board status * Defense Nuclear Facilities Safety Board (DNSFB) visit * Senator Tom Udall's

  14. Spin Hall magnetoresistance in CoFe2O4/Pt films (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Authors: Wu, Hao 1 ; Qintong, Zhang 1 ; Caihua, Wan 1 ; Ali, Syed Shahbaz 1 ; Yuan, Zhonghui 1 ; You, Lu 2 ; Wang, Junling 2 ; Choi, Yongseong 3 ; Han, Xiufeng 1 ...

  15. Former Herring-Hall-Marvin Safe Company Site in Hbmilton, Ohio

    Office of Legacy Management (LM)

    ... A fris k is a search for radioactive material that may have ... is the to enter into . 5. Grantor Resoonsibilitv - The Grantor responsibility is set out within the . terms and ...

  16. Hole carrier in MgB{sub 2} characterized by Hall measurements...

    Office of Scientific and Technical Information (OSTI)

    doped YBasub 2Cusub 3Osub y superconductors. copyright 2001 American Institute of Physics. ... OSTI Identifier: 40230768 Resource Type: Journal Article Resource Relation: ...

  17. September 24, 2014 in 100E Hildebrand Hall | Center for GasSeparation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    University) Photochromic MOFs: Reversible Generation of Singlet Oxygen Kyungmin Choi (Dept. of Chemistry, UC Berkeley) Supercapacitors of Nanocrystalline Metal-Organic Frameworks...

  18. TBH-0042 - In the Matter of Curtis Hall | Department of Energy

    Office of Environmental Management (EM)

    TBB-0049 - In the Matter of Gary S. Vander Boegh TBB-0049 - In the Matter of Gary S. Vander Boegh This letter concerns the complaint of retaliation that you filed with the Department of Energy (DOE) under 10 C.F.R. Part 708. On September 6, 2006, the Office of Hearings and Appeals (OHA) received your petition for Secretarial review of the August 3 jurisdictional appeal decision issued by the OHA Director. Under the Part 708 regulations, the Secretary will reverse or revise an appeal decision by

  19. Microsoft PowerPoint - WIPP Town Hall Meeting 9-3-15

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bryson * Radiation presentation - Walter MacMillan * Audience questions * In house * Internet * Closing comments - Dana Bryson www.energy.govEM 3 Update on CBFO and WIPP...

  20. Cathode for a hall-heroult type electrolytic cell for producing aluminum

    DOE Patents [OSTI]

    Brown, Craig W.

    2004-04-13

    A method of producing aluminum from alumina in an electrolytic cell including using a cathode comprised of a base material having low electrical conductivity and wettable with molten aluminum to form a reaction layer having a high electrical conductivity on said base layer and a cathode bar extending from said reaction layer through said base material to conduct electrical current from said reaction layer.