National Library of Energy BETA

Sample records for black diamond power

  1. ORC Seminar Series Presents: "Diamond adds brilliance: Power scaling

    E-Print Network [OSTI]

    Molinari, Marc

    ORC Seminar Series Presents: "Diamond adds brilliance: Power scaling diamond Raman lasers: Building 46, Rm 4050 (ORC Boardroom) Abstract: In this presentation I will review my work to date on power formatting for high-brightness laser diode arrays and most recently power scaling diamond Raman lasers. http://www.orc

  2. Black Diamond Power Co | Open Energy Information

    Open Energy Info (EERE)

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  3. Zr/oxidized diamond interface for high power Schottky diodes

    SciTech Connect (OSTI)

    Traoré, A., E-mail: aboulaye.traore@neel.cnrs.fr; Muret, P.; Fiori, A.; Eon, D.; Gheeraert, E. [Univ. Grenoble Alpes, Inst NEEL, F-38042 Grenoble (France); CNRS, Inst NEEL, F-38042 Grenoble (France); Pernot, J., E-mail: julien.pernot@neel.cnrs.fr [Univ. Grenoble Alpes, Inst NEEL, F-38042 Grenoble (France); CNRS, Inst NEEL, F-38042 Grenoble (France); Institut Universitaire de France, 103 Boulevard Saint-Michel, F-75005 Paris (France)

    2014-02-03

    High forward current density of 10{sup 3} A/cm{sup 2} (at 6 V) and a breakdown field larger than 7.7 MV/cm for diamond diodes with a pseudo-vertical architecture, are demonstrated. The power figure of merit is above 244 MW/cm{sup 2} and the relative standard deviation of the reverse current density over 83 diodes is 10% with a mean value of 10{sup ?9} A/cm{sup 2}. These results are obtained with zirconium as Schottky contacts on the oxygenated (100) oriented surface of a stack comprising an optimized lightly boron doped diamond layer on a heavily boron doped one, epitaxially grown on a Ib substrate. The origin of such performances are discussed.

  4. Black Hills Energy- Solar Power Program

    Broader source: Energy.gov [DOE]

    All incentive payments are subject to the availability of funds and a pre-installation site inspection. Black Hills Energy has established participation caps for each tier. The status of funding ...

  5. Black Hills Power Inc | Open Energy Information

    Open Energy Info (EERE)

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  6. Power Law Corrections to BTZ Black Hole Entropy

    E-Print Network [OSTI]

    Dharm Veer Singh

    2014-11-14

    We study the quantum scalar field in the background of BTZ black hole and evaluate the entanglement entropy of the non-vacuum states. The entropy is proportional to the area of event horizon for the ground state, but the area law is violated in the case of non-vacuum states (first excited state and mixed states) and the corrections scale as power law.

  7. Powering AGNs with super-critical black holes

    E-Print Network [OSTI]

    A. Avgoustidis; R. Jimenez; L. Alvarez-Gaume; M. A. Vazquez-Mozo

    2009-05-13

    We propose a novel mechanism for powering the central engines of Active Galactic Nuclei through super-critical (type II) black hole collapse. In this picture, ~$10^3 M_\\odot$ of material collapsing at relativistic speeds can trigger a gravitational shock, which can eject a large percentage of the collapsing matter at relativistic speeds, leaving behind a "light" black hole. In the presence of a poloidal magnetic field, the plasma collimates along two jets, and the associated electron synchrotron radiation can easily account for the observed radio luminosities, sizes and durations of AGN jets. For Lorentz factors of order 100 and magnetic fields of a few hundred $\\mu G$, synchrotron electrons can shine for $10^6$ yrs, producing jets of sizes of order 100 kpc. This mechanism may also be relevant for Gamma Ray Bursts and, in the absence of magnetic field, supernova explosions.

  8. BlackLight Power Inc | Open Energy Information

    Open Energy Info (EERE)

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  9. Highly c-axis oriented GaN films grown on free-standing diamond substrates for high-power devices

    SciTech Connect (OSTI)

    Zhang, D. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Bian, J.M., E-mail: jmbian@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Qin, F.W.; Wang, J.; Pan, L. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Zhao, J.M. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Zhao, Y.; Bai, Y.Z. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Du, G.T. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2011-10-15

    Highlights: {yields} GaN films are deposited on diamond substrates by ECR-PEMOCVD. {yields} Influence of deposition temperature on the properties of samples is investigated. {yields} Properties of GaN films are dependent on the deposition temperature. -- Abstract: GaN films with highly c-axis preferred orientation are deposited on free-standing thick diamond films by low temperature electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition (ECR-PEMOCVD). The TMGa and N{sub 2} are applied as precursors of Ga and N, respectively. The quality of as-grown GaN films are systematically investigated as a function of deposition temperature by means of X-ray diffraction (XRD) analysis, Hall Effect measurement (HL), room temperature photoluminescence (PL) and atomic force microscopy (AFM). The results show that the dense and uniformed GaN films with highly c-axis preferred orientation are successfully achieved on free-standing diamond substrates under optimized deposition temperature of 400 {sup o}C, and the room temperature PL spectra of the optimized GaN film show a intense ultraviolet near band edge emission and a weak yellow luminescence. The obtained GaN/diamond structure has great potential for the development of high-power semiconductor devices due to its excellent heat dissipation nature.

  10. Squeezars: Tidally powered stars orbiting a massive black hole

    E-Print Network [OSTI]

    Alexander, T; Alexander, Tal; Morris, Mark

    2003-01-01

    We propose that there exists a class of transient sources, "squeezars", which are stars caught in highly eccentric orbits around a massive (m<10^8 Mo) black hole (MBH), whose atypically high luminosity (up to a significant fraction of their Eddington luminosity) is powered by tidal interactions with the MBH. Their existence follows from the presence of a mass sink, the MBH, in the galactic center, which drives a flow of stars into nearly radial orbits to replace those it has destroyed. We consider two limits for the stellar response to tidal heating: surface heating with radiative cooling ("hot squeezars") and bulk heating with adiabatic expansion ("cold squeezars"), and calculate the evolution of the squeezar orbit, size, luminosity and effective temperature. The squeezar formation rate is only ~0.05 that of tidal disruption flares, but squeezar lifetimes are many orders of magnitude longer, and so future observations of squeezars in nearby galaxies can probe the tidal process that feeds MBHs and the effe...

  11. Powerful, Rotating Disk Winds from Stellar-mass Black Holes

    E-Print Network [OSTI]

    Miller, J M; Kaastra, J; Kallman, T; King, A L; Proga, D; Raymond, J; Reynolds, C S

    2015-01-01

    We present an analysis of ionized X-ray disk winds observed in the Fe K band of four stellar-mass black holes observed with Chandra, including 4U 1630-47, GRO J1655-40, H 1743-322, and GRS 1915+105. High-resolution photoionization grids were generated in order to model the data. Third-order gratings spectra were used to resolve complex absorption profiles into atomic effects and multiple velocity components. The Fe XXV line is found to be shaped by contributions from the intercombination line (in absorption), and the Fe XXVI line is detected as a spin-orbit doublet. The data require 2-3 absorption zones, depending on the source. The fastest components have velocities approaching or exceeding 0.01c, increasing mass outflow rates and wind kinetic power by orders of magnitude over prior single-zone models. The first-order spectra require re-emission from the wind, broadened by a degree that is loosely consistent with Keplerian orbital velocities at the photoionization radius. This suggests that disk winds are ro...

  12. Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets

    E-Print Network [OSTI]

    Jeffrey E. McClintock; Ramesh Narayan; James F. Steiner

    2013-06-28

    The spins of ten stellar black holes have been measured using the continuum-fitting method. These black holes are located in two distinct classes of X-ray binary systems, one that is persistently X-ray bright and another that is transient. Both the persistent and transient black holes remain for long periods in a state where their spectra are dominated by a thermal accretion disk component. The spin of a black hole of known mass and distance can be measured by fitting this thermal continuum spectrum to the thin-disk model of Novikov and Thorne; the key fit parameter is the radius of the inner edge of the black hole's accretion disk. Strong observational and theoretical evidence links the inner-disk radius to the radius of the innermost stable circular orbit, which is trivially related to the dimensionless spin parameter a_* of the black hole (|a_*| 0.95. The robustness of the method is demonstrated by the dozens or hundreds of independent and consistent measurements of spin that have been obtained for several black holes, and through careful consideration of many sources of systematic error. Among the results discussed is a dichotomy between the transient and persistent black holes; the latter have higher spins and larger masses. Also discussed is recently discovered evidence in the transient sources for a correlation between the power of ballistic jets and black hole spin.

  13. Black Hills Power, Inc. Smart Grid Project | Open Energy Information

    Open Energy Info (EERE)

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  14. Black Hills Power Inc (Montana) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin:Pontiac Biomass Facility JumpII Jump to:Bitworks WindBlack

  15. Outgoing electromagnetic power induced from pair plasma falling into a rotating black hole

    E-Print Network [OSTI]

    Kojima, Yasufumi

    2015-01-01

    We examine energy conversion from accreting pair plasma to outgoing Poynting flux by black hole rotation. Our approach is based on a two-fluid model consisting of collisionless pair plasma. The electric potential is not constant along magnetic field lines, unlike an ideal magnetohydrodynamics approximation. We show how and where longitudinal electric fields and toroidal magnetic fields are generated by the rotation, whereas they vanish everywhere for radial flow in a split monopole magnetic field in a Schwarzschild black hole. Outgoing electromagnetic power in a steady state is calculated by applying the WKB method to the perturbation equations for a small spin parameter. In our model, the luminosity has a peak in the vicinity of the black hole, but is damped toward the event horizon and infinity. The power at the peak is of the same order as that in the Blandford--Znajek process, although the physical mechanism is different.

  16. Fundamentals and application of materials integration for low-power piezoelectrically actuated ultra-nanocrystalline diamond MEMS/NEMS.

    SciTech Connect (OSTI)

    Auciello, O.; Srinivasan, S.; Hiller, J.; Kabius, B. (Center for Nanoscale Materials); ( MSD)

    2009-01-01

    Most current micro/nanoelectromechanical systems (MEMS/NEMS) are based on silicon. However, silicon exhibits relatively poor mechanical/tribological properties, compromising applications to several projected MEMS/NEMS devices, particularly those that require materials with high Young's modulus for MEMS resonators or low surface adhesion forces for MEMS/NEMS working in conditions with extensive surface contact. Diamond films with superior mechanical/tribological properties provide an excellent alternative platform material. Ultrananocrystalline diamond (UNCD{cflx W}) in film form with 2-5 nm grains exhibits excellent properties for high-performance MEMS/NEMS devices. Concurrently, piezoelectric Pb(Zr{sub x}Ti{sub 1-x})O{sub 3} (PZT) films provide high sensitivity/low electrical noise for sensing/high-force actuation at relatively low voltages. Therefore, integration of PZT and UNCD films provides a high-performance platform for advanced MEMS/NEMS devices. This paper describes the bases of such integration and demonstration of low voltage piezoactuated hybrid PZT/UNCD cantilevers.

  17. Thermodynamics of higher dimensional topological dilaton black holes with power-law Maxwell field

    E-Print Network [OSTI]

    M. Kord Zangeneh; A. Sheykhi; M. H. Dehghani

    2015-05-02

    In this paper, we extend the study on the nonlinear power-law Maxwell field to dilaton gravity. We introduce the $(n+1)$-dimensional action in which gravity is coupled to a dilaton and power-law nonlinear Maxwell field, and obtain the field equations by varying the action. We construct a new class of higher dimensional topological black hole solutions of Einstein-dilaton theory coupled to a power-law nonlinear Maxwell field and investigate the effects of the nonlinearity of the Maxwell source as well as the dilaton field on the properties of the spacetime. Interestingly enough, we find that the solutions exist provided one assumes three Liouville-type potentials for the dilaton field, and in case of the Maxwell field one of the Liouville potential vanishes. After studying the physical properties of the solutions, we compute the mass, charge, electric potential and temperature of the topological dilaton black holes. We also study thermodynamics and thermal stability of the solutions and disclose the effects of the dilaton field and the power-law Maxwell field on the thermodynamics of these black holes. Finally, we comment on the dynamical stability of the obtained solutions in four-dimensions.

  18. The Extended Power Law as Intrinsic Signature For a Black Hole

    E-Print Network [OSTI]

    Lev Titarchuk; Thomas Zannias

    1997-08-27

    We analyze the exact general relativistic exact integro-differential equation of radiative transfer describing the interaction of low energy photons with a Maxwellian distribution of hot electrons in gravitational field of a Schwarzschild black hole. We prove that due to Comptonization an initial arbitrary spectrum of low energy photons unavoidably results in spectra characterized by an extended power-law feature. We examine the spectral index by using both analytical and numerical methods for a variety of physical parameters as such the plasma temperature and the mass accretion rate. The presence of the event horizon as well as the behaviour of the null geodesics in its vicinity largely determine the dependence of the spectral index on the flow parameters. We come to the conclusion that the bulk motion of a converging flow is more efficient in upscattering photons than thermal Comptonization provided that the electron temperature in the flow is of order of a few keV or less. In this case, the spectrum observed at infinity consists of a soft component produced by those input photons that escape after a few scatterings without any significant energy change and of hard component (described by a power law) produced by the photons that underwent significant upscattering. The luminosity of the power-law component is relatively small compared to that of the soft component. For accretion into black hole the spectral energy index of the power-law is always higher than one for plasma temperature of order of a few keV. This result suggests that the bulk motion Comptonization might be responsible for the power-law spectra seen in the black-hole X-ray sources.

  19. Electrically conductive diamond electrodes

    DOE Patents [OSTI]

    Swain, Greg (East Lansing, MI); Fischer, Anne (Arlington, VA),; Bennett, Jason (Lansing, MI); Lowe, Michael (Holt, MI)

    2009-05-19

    An electrically conductive diamond electrode and process for preparation thereof is described. The electrode comprises diamond particles coated with electrically conductive doped diamond preferably by chemical vapor deposition which are held together with a binder. The electrodes are useful for oxidation reduction in gas, such as hydrogen generation by electrolysis.

  20. Accretion Disc Turbulence and the X-Ray Power Spectra of Black Hole High States

    E-Print Network [OSTI]

    Michael A. Nowak; Robert V. Wagoner

    1994-10-06

    The high state of black hole candidates is characterized by a quasi- thermal emission component at $kT \\sim 1$ keV. In addition, this state tends to have very low variability which indicates that it is relatively stable, at least on {\\it short} time scales. Most models of the high state imply that the bulk of the emission comes from an optically thick accretion disc; therefore, this state may be an excellent laboratory for testing our ideas about the physics of accretion discs. In this work we consider the implications of assuming that accretion disc viscosity arises from some form of turbulence. Specifically, we consider the simple case of three dimensional hydrodynamic turbulence. It is found that the coupling of such turbulence to acoustic modes in the disc can alter the disc emission. We calculate the amplitude and frequencies of this modulation, and we express our results in terms of the X-ray power spectral density. We compare our calculations with observations of the black hole candidate GS 1124-683, and show that for certain parameters we can reproduce some of the high frequency power. We then briefly explore mechanisms for producing the low frequency power, and note the difficulty that a single variability mechanism has in reproducing the full range of observed variability. In addition, we outline ways in which future spacecraft missions -- such as USA and XTE -- can further constrain our model, especially at frequencies above $\\sim 10^2$ Hz.

  1. Space-time diamonds

    E-Print Network [OSTI]

    Daiqin Su; T. C. Ralph

    2015-07-02

    We show that the particle number distribution of diamond modes, modes that are localised in a finite space-time region, are thermal for the Minkowski vacuum state of a massless scalar field, an analogue to the Unruh effect. The temperature of the diamond is inversely proportional to its size. An inertial observer can detect this thermal radiation by coupling to the diamond modes using an appropriate energy scaled detector. We further investigate the correlations between various diamonds and find that entanglement between adjacent diamonds dominates.

  2. $P-V$ criticality of AdS black hole in the Einstein-Maxwell-power-Yang-Mills gravity

    E-Print Network [OSTI]

    Ming Zhang; Zhan-Ying Yang; De-Cheng Zou; Wei Xu; Rui-Hong Yue

    2014-12-03

    We study the $P-V$ critical behaivor of N-dimensional AdS black holes in Einstein-Maxwell-power-Yang-Mills gravity. Our results show the existence of the Van der Waals like small-large black hole phase transitions when taking some special values of charges of the Maxwell and Yang-Mills (YM) fields. Further to calculate the critical exponents of the black holes at the critical point, we find that they are the same as those in the Van der Waals liquid-gas system.

  3. Thermally stable diamond brazing

    DOE Patents [OSTI]

    Radtke, Robert P. (Kingwood, TX)

    2009-02-10

    A cutting element and a method for forming a cutting element is described and shown. The cutting element includes a substrate, a TSP diamond layer, a metal interlayer between the substrate and the diamond layer, and a braze joint securing the diamond layer to the substrate. The thickness of the metal interlayer is determined according to a formula. The formula takes into account the thickness and modulus of elasticity of the metal interlayer and the thickness of the TSP diamond. This prevents the use of a too thin or too thick metal interlayer. A metal interlayer that is too thin is not capable of absorbing enough energy to prevent the TSP diamond from fracturing. A metal interlayer that is too thick may allow the TSP diamond to fracture by reason of bending stress. A coating may be provided between the TSP diamond layer and the metal interlayer. This coating serves as a thermal barrier and to control residual thermal stress.

  4. Diamond tool machining of materials which react with diamond

    DOE Patents [OSTI]

    Lundin, Ralph L. (Los Alamos, NM); Stewart, Delbert D. (Los Alamos, NM); Evans, Christopher J. (Gaithersburg, MD)

    1992-01-01

    Apparatus for the diamond machining of materials which detrimentally react with diamond cutting tools in which the cutting tool and the workpiece are chilled to very low temperatures. This chilling halts or retards the chemical reaction between the workpiece and the diamond cutting tool so that wear rates of the diamond tool on previously detrimental materials are comparable with the diamond turning of materials which do not react with diamond.

  5. Diamond tool machining of materials which react with diamond

    DOE Patents [OSTI]

    Lundin, R.L.; Stewart, D.D.; Evans, C.J.

    1992-04-14

    An apparatus is described for the diamond machining of materials which detrimentally react with diamond cutting tools in which the cutting tool and the workpiece are chilled to very low temperatures. This chilling halts or retards the chemical reaction between the workpiece and the diamond cutting tool so that wear rates of the diamond tool on previously detrimental materials are comparable with the diamond turning of materials which do not react with diamond. 1 figs.

  6. Diamond/diamond-like thin film growth in a butane plasma on unetched, unheated, N-type Si(100) substrates

    SciTech Connect (OSTI)

    Williams, E.S.; Richardson, J.S. Jr.; Anderson, D.; Starkey, K.

    1995-06-01

    Deposition of diamond/diamond-like thin films on unetched, unheated, n-type Si(100) substrates in a butane plasma is reported. An interconnection between values of index of refraction, hydrogen flow rate, butane flow rate and Rf power was determined. The H{sub 2} and C{sub 4}H{sub 10} molecules are disassociated by Rf energy to create a plasma. Carbon from the butane forms a thin diamond/diamond-like film on a suitable substrate, which in the current investigation, is n-type Si(100).

  7. Amorphous diamond films

    DOE Patents [OSTI]

    Falabella, Steven (Livermore, CA)

    1998-01-01

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions.

  8. Can black-hole neutrino-cooled disks power short gamma-ray bursts?

    E-Print Network [OSTI]

    Liu, Tong; Hou, Shu-Jin; Gu, Wei-Min

    2015-01-01

    Stellar-mass black holes (BHs) surrounded by neutrino-dominated accretion flows (NDAFs) are the plausible candidates to power gamma-ray bursts (GRBs) via neutrinos emission and their annihilation. The progenitors of short-duration GRBs (SGRBs) are generally considered to be compact binaries mergers. According to the simulation results, the disk mass of the NDAF has been limited after merger events. We can estimate such disk mass by using the current SGRB observational data and fireball model. The results show that the disk mass of a certain SGRB mainly depends on its output energy, jet opening angle, and central BH characteristics. Even for the extreme BH parameters, some SGRBs require massive disks, which approach or exceed the limits in simulations. We suggest that there may exist alternative magnetohydrodynamic processes or some mechanisms increasing the neutrino emission to produce SGRBs with the reasonable BH parameters and disk mass.

  9. Diesel Futures Forget the black soot and smoke. Modern diesel-powered cars are quiet, clean and fast.

    E-Print Network [OSTI]

    Diesel Futures Forget the black soot and smoke. Modern diesel-powered cars are quiet, clean at their tachometers to be sure that they were running. You would not expect that of a diesel, however. Yet these are diesel engines. The world has been looking to gas/electric hybrids and fuel cells for future fuel

  10. Diesel Futures Forget the black soot and smoke. Modern diesel-powered cars are quiet, clean and fast.

    E-Print Network [OSTI]

    passenger-car importer, Volkswagen, with new models of their own. As of now, only the VW Jetta/Golf/Beetle 1Diesel Futures Forget the black soot and smoke. Modern diesel-powered cars are quiet, clean, and be within a gnat's whisker of a gasoline hybrid like the Prius. The studies of total energy consumption

  11. Quantum Engineering in Diamond 

    E-Print Network [OSTI]

    Chen, Jeson

    2015-08-06

    of the NV centers yield in bulk diamond, nanodiamond (ND) size reduction, photocurrent study of the defect band-trap electronic structure in diamonds, and optimization of high-speed NV qubit control. For NV centers yield optimization, both the experimental...

  12. Diamond nucleation using polyethene

    DOE Patents [OSTI]

    Morell, Gerardo; Makarov, Vladimir; Varshney, Deepak; Weiner, Brad

    2013-07-23

    The invention presents a simple, non-destructive and non-abrasive method of diamond nucleation using polyethene. It particularly describes the nucleation of diamond on an electrically viable substrate surface using polyethene via chemical vapor deposition (CVD) technique in a gaseous environment.

  13. Thermodynamics of topological black holes in Brans-Dicke gravity with a power-law Maxwell field

    E-Print Network [OSTI]

    Zangeneh, M Kord; Sheykhi, A

    2015-01-01

    In this paper, we present a new class of higher dimensional exact topological black hole solutions of the Brans-Dicke theory in the presence of a power-law Maxwell field as the matter source. For this aim, we introduce a conformal transformation which transforms the Einstein-dilaton-power-law Maxwell gravity Lagrangian to the Brans-Dicke-power-law Maxwell theory one. Then, by using this conformal transformation, we obtain the desired solutions. Next, we study the properties of the solutions and conditions under which we have black holes. Interestingly enough, we show that there is a cosmological horizon in the presence of a negative cosmological constant. Finally, we calculate the temperature and charge and then by calculating the Euclidean action, we obtain the mass, the entropy and the electromagnetic potential energy. We find that the entropy does not respect the area law, and also the conserved and thermodynamic quantities are invariant under conformal transformation. Using these thermodynamic and conserv...

  14. Discovery of 0.08 Hz QPO in the power spectrum of black hole candidate XTE J1118+480

    E-Print Network [OSTI]

    M. Revnivtsev; R. Sunyaev; K. Borozdin

    2000-05-10

    We found a strong QPO feature at 0.085+/-0.002 Hz in the power spectrum of X-ray transient XTE J1118+480. The QPO was detected in PCA/RXTE data with an amplitude close to 10% rms, and the width 0.034+/-0.006 Hz. The shape of the power spectrum is typical for black hole candidates: almost flat at frequencies lower than 0.03 Hz, roughly power law with slope ~1.2 from 0.03 to 1 Hz, with a following steepening to ~1.6 at higher frequencies. The hard energy spectrum detected up to ~150 keV and the absence of significant X-ray variability at the high frequencies above 100 Hz strongly support the identification of XTE J1118+480 as black hole transient.

  15. ENERGY-DEPENDENT POWER SPECTRAL STATES AND ORIGIN OF APERIODIC VARIABILITY IN BLACK HOLE BINARIES

    SciTech Connect (OSTI)

    Yu Wenfei; Zhang Wenda, E-mail: wenfei@shao.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)

    2013-06-20

    We found that the black hole candidate MAXI J1659-152 showed distinct power spectra, i.e., power-law noise (PLN) versus band-limited noise (BLN) plus quasi-periodic oscillations (QPOs) below and above about 2 keV, respectively, in observations with Swift and the Rossi X-ray Timing Explorer during the 2010 outburst, indicating a high energy cutoff of the PLN and a low energy cutoff of the BLN and QPOs around 2 keV. The emergence of the PLN and the fading of the BLN and QPOs initially took place below 2 keV when the source entered the hard intermediate state and settled in the soft state three weeks later. The evolution was accompanied by the emergence of the disk spectral component and decreases in the amplitudes of variability in the soft and hard X-ray bands. Our results indicate that the PLN is associated with an optically thick disk in both hard and intermediate states, and the power spectral state is independent of the X-ray energy spectral state in a broadband view. We suggest that in the hard or intermediate state, the BLN and QPOs emerge from the innermost hot flow subjected to Comptonization, while the PLN originates from the optically thick disk farther out. The energy cutoffs of the PLN and the BLN or QPOs then follow the temperature of the seed photons from the inner edge of the optically thick disk, while the high frequency cutoff of the PLN follows the orbital frequency of the inner edge of the optically thick disk as well.

  16. Ultrananocrystalline Diamond (UNCD) Seal Faces | Department of...

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

    Diamond (UNCD) Seal Faces Ultrananocrystalline Diamond (UNCD) Seal Faces New Diamond Coatings Reduce Friction and Improve Performance of Mechanical Seals Mechanical seals are used...

  17. STATUS OF DIAMOND SECONDARY EMISSION ENHANCED PHOTOCATHODE

    SciTech Connect (OSTI)

    RAO,T.; BEN-ZVI, I.; CHANG, X.; GRIMES, J.; GROVER, R.; ISAKOVIC, A.; SMEDLEY, J.; TODD, R.; WARREN, J.; WU, Q.

    2007-05-25

    The diamond secondary emission enhanced photocathode (SEEP) provides an attractive alternative for simple photo cathodes in high average current electron injectors. It reduces the laser power required to drive the cathode, simultaneously isolating the cathode and the FW cavity from each other, thereby protecting them from contamination and increasing their life time. In this paper, we present the latest results on the secondary electron yield using pulsed thermionic and photo cathodes as primary electron sources, shaping the diamond using laser ablation and reactive ion etching as well as the theoretical underpinning of secondary electron generation and preliminary results of modeling.

  18. Tidal Disruption and Magnetic Flux Capture: Powering a Jet from a Quiescent Black Hole

    E-Print Network [OSTI]

    Kelley, Luke Zoltan; Narayan, Ramesh

    2014-01-01

    The transient Swift J1644+57 is believed to have been produced by an unlucky star wandering too close to a supermassive black hole (BH) leading to a tidal disruption event. This unusual flare displayed highly super-Eddington X-ray emission which likely originated in a relativistic, collimated jet. This presents challenges to modern accretion and jet theory as upper limits of prior BH activity, which we obtain from the radio afterglow of this event, imply that both the pre-disruption BH and stellar magnetic fluxes fall many orders of magnitude short of what is required to power the observed X-ray luminosity. We argue that a pre-existing, "fossil" accretion disc can contain a sufficient reservoir of magnetic flux and that the stellar debris stream is capable of dragging this flux into the BH. To demonstrate this, we perform local, 3D magnetohydrodynamic simulations of the disc--stream interaction and demonstrate that the interface between the two is unstable to mixing. This mixing entrains a sufficient amount o...

  19. Amorphous diamond films

    DOE Patents [OSTI]

    Falabella, S.

    1998-06-09

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  20. On-Chip Diamond Raman Laser

    E-Print Network [OSTI]

    Latawiec, Pawel; Burek, Michael J; Hausmann, Birgit J M; Bulu, Irfan; Loncar, Marko

    2015-01-01

    Synthetic single-crystal diamond has recently emerged as a promising platform for Raman lasers at exotic wavelengths due to its giant Raman shift, large transparency window and excellent thermal properties yielding a greatly enhanced figure-of-merit compared to conventional materials. To date, diamond Raman lasers have been realized using bulk plates placed inside macroscopic cavities, requiring careful alignment and resulting in high threshold powers (~W-kW). Here we demonstrate an on-chip Raman laser based on fully-integrated, high quality-factor, diamond racetrack micro-resonators embedded in silica. Pumping at telecom wavelengths, we show Stokes output discretely tunable over a ~100nm bandwidth around 2-{\\mu}m with output powers >250 {\\mu}W, extending the functionality of diamond Raman lasers to an interesting wavelength range at the edge of the mid-infrared spectrum. Continuous-wave operation with only ~85 mW pump threshold power in the feeding waveguide is demonstrated along with continuous, mode-hop-fr...

  1. Thermodynamics of topological black holes in Brans-Dicke gravity with a power-law Maxwell field

    E-Print Network [OSTI]

    M. Kord Zangeneh; M. H. Dehghani; A. Sheykhi

    2015-09-20

    In this paper, we present a new class of higher dimensional exact topological black hole solutions of the Brans-Dicke theory in the presence of a power-law Maxwell field as the matter source. For this aim, we introduce a conformal transformation which transforms the Einstein-dilaton-power-law Maxwell gravity Lagrangian to the Brans-Dicke-power-law Maxwell theory one. Then, by using this conformal transformation, we obtain the desired solutions. Next, we study the properties of the solutions and conditions under which we have black holes. Interestingly enough, we show that there is a cosmological horizon in the presence of a negative cosmological constant. Finally, we calculate the temperature and charge and then by calculating the Euclidean action, we obtain the mass, the entropy and the electromagnetic potential energy. We find that the entropy does not respect the area law, and also the conserved and thermodynamic quantities are invariant under conformal transformation. Using these thermodynamic and conserved quantities, we show that the first law of black hole thermodynamics is satisfied on the horizon.

  2. wvBLACK DIAMONDS table of contents

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    'RE ON THE WEB! www.mine.cemr.wvu.edu Statler College of Engineering and Mineral Resources DEPARTMENT OF MINING

  3. wvBLACK DIAMONDS table of contents

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    with mining! WE'RE ON THE WEB! www.mine.cemr.wvu.edu College of Engineering and Mineral Resources DEPARTMENT

  4. The balance of power: accretion and feedback in stellar mass black holes

    E-Print Network [OSTI]

    Fender, Rob

    2015-01-01

    In this review we discuss the population of stellar-mass black holes in our galaxy and beyond, which are the extreme endpoints of massive star evolution. In particular we focus on how we can attempt to balance the available accretion energy with feedback to the environment via radiation, jets and winds, considering also possible contributions to the energy balance from black hole spin and advection. We review quantitatively the methods which are used to estimate these quantities, regardless of the details of the astrophysics close to the black hole. Once these methods have been outlined, we work through an outburst of a black hole X-ray binary system, estimating the flow of mass and energy through the different accretion rates and states. While we focus on feedback from stellar mass black holes in X-ray binary systems, we also consider the applicability of what we have learned to supermassive black holes in active galactic nuclei. As an important control sample we also review the coupling between accretion an...

  5. Diamond-graphite field emitters

    DOE Patents [OSTI]

    Valone, Steven M. (Santa Fe, NM)

    1997-01-01

    A field emission electron emitter comprising an electrode of diamond and a conductive carbon, e.g., graphite, is provided.

  6. The powerful jet of an off-nuclear intermediate-mass black hole in the spiral galaxy NGC 2276

    E-Print Network [OSTI]

    Mezcua, M; Lobanov, A P; Sutton, A D

    2015-01-01

    Jet ejection by accreting black holes is a mass invariant mechanism unifying stellar and supermassive black holes (SMBHs) that should also apply for intermediate-mass black holes (IMBHs), which are thought to be the seeds from which SMBHs form. We present the detection of an off-nuclear IMBH of $\\sim$5 $\\times$ 10$^{4}$ M$_\\odot$ located in an unusual spiral arm of the galaxy NGC 2276 based on quasi-simultaneous \\textit{Chandra} X-ray observations and European VLBI Network (EVN) radio observations. The IMBH, NGC2276-3c, possesses a 1.8 pc radio jet that is oriented in the same direction as large-scale ($\\sim$650 pc) radio lobes and whose emission is consistent with flat to optically thin synchrotron emission between 1.6 GHz and 5 GHz. Its jet kinetic power ($4 \\times 10^{40}$ erg s$^{-1}$) is comparable to its radiative output and its jet efficiency ($\\geq$ 46\\%) is as large as that of SMBHs. A region of $\\sim$300 pc along the jet devoid of young stars could provide observational evidence of jet feedback from...

  7. Testing the Kerr-nature of stellar-mass black hole candidates by combining the continuum-fitting method and the power estimate of transient ballistic jets

    E-Print Network [OSTI]

    Cosimo Bambi

    2012-01-25

    Astrophysical black hole candidates are thought to be the Kerr black holes predicted by General Relativity, as these objects cannot be explained otherwise without introducing new physics. However, there is no observational evidence that the space-time around them is really described by the Kerr solution. The Kerr black hole hypothesis can be tested with the already available X-ray data by extending the continuum-fitting method, a technique currently used by astronomers to estimate the spins of stellar-mass black hole candidates. In general, we cannot put a constraint on possible deviations from the Kerr geometry, but only on some combination between these deviations and the spin. The measurement of the radio power of transient jets in black hole binaries can potentially break this degeneracy, thus allowing for testing the Kerr-nature of these objects.

  8. Lower pressure synthesis of diamond material

    DOE Patents [OSTI]

    Lueking, Angela (State College, PA); Gutierrez, Humberto (State College, PA); Narayanan, Deepa (Redmond, WA); Burgess Clifford, Caroline E. (State College, PA); Jain, Puja (King Of Prussia, PA)

    2010-07-13

    Methods of synthesizing a diamond material, particularly nanocrystalline diamond, diamond-like carbon and bucky diamond are provided. In particular embodiments, a composition including a carbon source, such as coal, is subjected to addition of energy, such as high energy reactive milling, producing a milling product enriched in hydrogenated tetrahedral amorphous diamond-like carbon compared to the coal. A milling product is treated with heat, acid and/or base to produce nanocrystalline diamond and/or crystalline diamond-like carbon. Energy is added to produced crystalline diamond-like carbon in particular embodiments to produce bucky diamonds.

  9. Multifrequency spin resonance in diamond

    SciTech Connect (OSTI)

    Childress, Lilian; McIntyre, Jean

    2010-09-15

    Magnetic resonance techniques provide a powerful tool for controlling spin systems, with applications ranging from quantum information processing to medical imaging. Nevertheless, the behavior of a spin system under strong excitation remains a rich dynamical problem. In this paper, we examine spin resonance of the nitrogen-vacancy center in diamond under conditions outside the regime where the usual rotating-wave approximation applies, focusing on effects of multifrequency excitation and excitation with orientation parallel to the spin quantization axis. Strong-field phenomena such as multiphoton transitions and coherent destruction of tunneling are observed in the spectra and analyzed via numerical and analytic theory. In addition to illustrating the response of a spin system to strong multifrequency excitation, these observations may inform techniques for manipulating electron-nuclear spin quantum registers.

  10. Black oxide nanoparticles as durable solar absorbing material for high-temperature concentrating solar power system

    E-Print Network [OSTI]

    California at San Diego, University of

    Available online 8 January 2015 Keywords: Concentrating solar power Solar absorber Cobalt oxide Light trapping High temperature a b s t r a c t Concentrating solar power is becoming an increasingly important an increasingly urgent need for human society [1,2]. Concentrating solar power (CSP) systems (or solar thermal sys

  11. Is radio jet power linearly proportional to the product of central black hole mass and Eddington ratio in AGN?

    E-Print Network [OSTI]

    Liu, Xiang

    2014-01-01

    A model for the relation between radio jet power and the product of central black hole (BH) mass and Eddington ratio of AGN is proposed, and the model is examined with data from the literature. We find that radio jet power positively correlates but not linearly with the product of BH mass ($m$ in solar mass) and Eddington ratio ($\\lambda$), and the power law indices ($\\mu$) are significantly less than unity for relatively low accretion ($\\lambda<0.1$) AGN, $P_{j}\\propto (\\lambda m)^{\\mu}$, in the radio galaxies and the Seyfert galaxies. This leads to a negative correlation between radio loudness and $\\lambda m$ for the low luminosity AGN, i.e. $R\\propto (\\lambda m)^{\\rho}$ with $\\rho=(7/6)\\mu-1<0$, which may be attributed to a contribution of BH spin to total jet power assuming that the spin induced jet is gradually suppressed as the accretion rate increases. Whereas, for the high-z quasars which often show the slope $\\mu\\geq1$, a positive correlation between the radio loudness and disc luminosity is pr...

  12. Diamond turning of glass

    SciTech Connect (OSTI)

    Blackley, W.S.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the critical cutting depth concepts for single point diamond turning of brittle, amorphous materials. Inorganic glasses and a brittle, thermoset polymer (organic glass) are the principal candidate materials. Interrupted cutting tests similar to those done in earlier research are Ge and Si crystals will be made to obtain critical depth values as a function of machining parameters. The results will provide systematic data with which to assess machining performance on glasses and amorphous materials

  13. Diamond films treated with alkali-halides

    DOE Patents [OSTI]

    Anderson, D.F.; Kwan, S.W.

    1997-04-08

    A secondary electron emitter is provided and includes a substrate with a diamond film, the diamond film is treated or coated with an alkali-halide. 5 figs.

  14. Diamond and Polycrystalline Diamond for MEMS Applications: Simulations and Experiments

    E-Print Network [OSTI]

    Çagin, Tahir

    Diamond and Polycrystalline Diamond for MEMS Applications: Simulations and Experiments Tahir C¸ a Communication Systems, El Segundo, CA 90025, U.S.A. Abstract To date most of the MEMS devices are been based both to surface chemistry and cohesive energy density of these likely MEMS bearing materials. Therefore

  15. Are Ultra Long Gamma Ray Bursts powered by a black hole spinning down?

    E-Print Network [OSTI]

    Nathanail, Antonios

    2015-01-01

    Gamma-ray bursts (GRBs) are violent explosions, coming from cosmological distances. They are detected in gamma-rays (also X-rays, UV, optical, radio) almost every day, and have typical durations of a few seconds to a few minutes. Some GRBs have been reported with extraordinary duration of 10^4 sec. These are called Ultra Long GRBs. It has been debated whether these form a new distinct class of events or whether they are similar to long GRBs. According to Blandford & Znajek (1977), the spin energy of a rotating black hole can be extracted electromagnetically, should the hole be endowed with a magnetic field supported by electric currents in a surrounding disk. We argue that this can be the case for the central engines of GRBs and we show that the duration of the burst depends on the magnetic flux accumulated on the event horizon of the black hole. We thus estimate the surface magnetic field of a possible progenitor star, and we conclude that an Ultra Long GRB may originate from a progenitor star with a rel...

  16. Optimization of Acetylene Black Conductive Additive andPolyvinylidene Difluoride Composition for High Power RechargeableLithium-Ion Cells

    SciTech Connect (OSTI)

    Liu, G.; Zheng, H.; Battaglia, V.S.; Simens, A.S.; Minor, A.M.; Song, X.

    2007-07-01

    Fundamental electrochemical methods were applied to study the effect of the acetylene black (AB) and the polyvinylidene difluoride (PVDF) polymer binder on the performance of high-power designed rechargeable lithium ion cells. A systematic study of the AB/PVDF long-range electronic conductivity at different weight ratios is performed using four-probe direct current tests and the results reported. There is a wide range of AB/PVDF ratios that satisfy the long-range electronic conductivity requirement of the lithium-ion cathode electrode; however, a significant cell power performance improvement is observed at small AB/PVDF composition ratios that are far from the long-range conductivity optimum of 1 to 1.25. Electrochemical impedance spectroscopy (EIS) tests indicate that the interfacial impedance decreases significantly with increase in binder content. The hybrid power pulse characterization results agree with the EIS tests and also show improvement for cells with a high PVDF content. The AB to PVDF composition plays a significant role in the interfacial resistance. We believe the higher binder contents lead to a more cohesive conductive carbon particle network that results in better overall all local electronic conductivity on the active material surface and hence reduced charge transfer impedance.

  17. High efficiency diamond solar cells

    DOE Patents [OSTI]

    Gruen, Dieter M. (Downers Grove, IL)

    2008-05-06

    A photovoltaic device and method of making same. A layer of p-doped microcrystalline diamond is deposited on a layer of n-doped ultrananocrystalline diamond such as by providing a substrate in a chamber, providing a first atmosphere containing about 1% by volume CH.sub.4 and about 99% by volume H.sub.2 with dopant quantities of a boron compound, subjecting the atmosphere to microwave energy to deposit a p-doped microcrystalline diamond layer on the substrate, providing a second atmosphere of about 1% by volume CH.sub.4 and about 89% by volume Ar and about 10% by volume N.sub.2, subjecting the second atmosphere to microwave energy to deposit a n-doped ultrananocrystalline diamond layer on the p-doped microcrystalline diamond layer. Electrodes and leads are added to conduct electrical energy when the layers are irradiated.

  18. A Diamond Nanowire Single Photon Antenna

    E-Print Network [OSTI]

    Tom Babinec; Birgit J. M. Hausmann; Mughees Khan; Yinan Zhang; Jero Maze; Philip R. Hemmer; Marko Loncar

    2009-10-28

    The development of a robust light source that emits one photon at a time is an outstanding challenge in quantum science and technology. Here, at the transition from many to single photon optical communication systems, fully quantum mechanical effects may be utilized to achieve new capabilities, most notably perfectly secure communication via quantum cryptography. Practical implementations place stringent requirements on the device properties, including stable photon generation, room temperature operation, and efficient extraction of many photons. Single photon light emitting devices based on fluorescent dye molecules, quantum dots, and carbon nanotube material systems have all been explored, but none have simultaneously demonstrated all criteria. Here, we describe the design, fabrication, and characterization of a bright source of single photons consisting of an individual Nitrogen-vacancy color center (NV center) in a diamond nanowire operating in ambient conditions. The nanowire plays a positive role in increasing the number of single photons collected from the NV center by an order of magnitude over devices based on bulk diamond crystals, and allows operation at an order of magnitude lower power levels. This result enables a new class of nanostructured diamond devices for room temperature photonic and quantum information processing applications, and will also impact fields as diverse as biological and chemical sensing, opto-mechanics, and scanning-probe microscopy.

  19. Black Pine Engineering

    Office of Energy Efficiency and Renewable Energy (EERE)

    Black Pine Engineering is commercializing a disruptive technology in the turbomachinery industry. Using a patented woven composite construction, Black Pine Engineering can make turbomachines (turbines, compressors) that are cheaper and lighter than competing technologies. Using this technology, Black Pine Engineering will sell turbo-compressors which solve the problem of wasted steam in geothermal power plants.

  20. A subpicotesla diamond magnetometer

    E-Print Network [OSTI]

    Thomas Wolf; Philipp Neumann; Kazuo Nakamura; Hitoshi Sumiya; Junichi Isoya; Jörg Wrachtrup

    2014-12-19

    Diamond defect centers are promising solid state magnetometers. Single centers allow for high spatial resolution field imaging but are limited in their magnetic field sensitivity to around 10 nT/Hz^(1/2) at room-temperature. Using defect center ensembles sensitivity can be scaled as N^(1/2) when N is the number of defects. In the present work we use an ensemble of 1e11 defect centers for sensing. By carefully eliminating all noise sources like laser intensity fluctuations, microwave amplitude and phase noise we achieve a photon shot noise limited field sensitivity of 0.9 pT/Hz^(1/2) at room-temperature with an effective sensor volume of 8.5e-4 mm^3. The smallest field we measured with our device is 100 fT. While this denotes the best diamond magnetometer sensitivity so far, further improvements using decoupling sequences and material optimization could lead to fT/Hz^(1/2) sensitivity.

  1. Fabrication of amorphous diamond films

    DOE Patents [OSTI]

    Falabella, S.

    1995-12-12

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  2. Amorphous-diamond electron emitter

    DOE Patents [OSTI]

    Falabella, Steven (Livermore, CA)

    2001-01-01

    An electron emitter comprising a textured silicon wafer overcoated with a thin (200 .ANG.) layer of nitrogen-doped, amorphous-diamond (a:D-N), which lowers the field below 20 volts/micrometer have been demonstrated using this emitter compared to uncoated or diamond coated emitters wherein the emission is at fields of nearly 60 volts/micrometer. The silicon/nitrogen-doped, amorphous-diamond (Si/a:D-N) emitter may be produced by overcoating a textured silicon wafer with amorphous-diamond (a:D) in a nitrogen atmosphere using a filtered cathodic-arc system. The enhanced performance of the Si/a:D-N emitter lowers the voltages required to the point where field-emission displays are practical. Thus, this emitter can be used, for example, in flat-panel emission displays (FEDs), and cold-cathode vacuum electronics.

  3. A procedure for diamond turning KDP crystals

    SciTech Connect (OSTI)

    Montesanti, R.C.; Thompson, S.L.

    1995-07-07

    A procedure and the equipment necessary for single-point diamond flycutting (loosely referred to as diamond turning) potassium di-hydrogen phosphate (KDP) crystals are described. It is based on current KDP diamond turning activities at the Lawrence Livermore National Laboratory (LLNL), drawing upon knowledge from the Nova crystal finishing development during the 1980`s and incorporating refinements from our efforts during 1995. In addition to describing a step-by-step process for diamond turning KDP, specific discussions are included on the necessary diamond tool geometry and edge sharpness, cutting fluid, and crystal preparation, handling, cleaning, and inspection. The authors presuppose that the reader is already familiar with diamond turning practices.

  4. Powerful radiative jets in super-critical accretion disks around non-spinning black holes

    E-Print Network [OSTI]

    Sadowski, Aleksander

    2015-01-01

    We describe a set of simulations of super-critical accretion onto a non-rotating supermassive BH. The accretion flow is radiation pressure dominated and takes the form of a geometrically thick disk with twin low-density funnels around the rotation axis. For accretion rates $\\gtrsim 10 \\dot M_{\\rm Edd}$, there is sufficient gas in the funnel to make this region optically thick. Radiation from the disk first flows into the funnel, after which it accelerates the optically thick funnel gas along the axis. The resulting jet is baryon-loaded and has a terminal density-weighted velocity $\\approx 0.3c$. Much of the radiative luminosity is converted into kinetic energy by the time the escaping gas becomes optically thin. For an observer viewing down the axis, the isotropic equivalent luminosity of total energy is as much as $10^{48}\\,\\rm erg\\,s^{-1}$ for a $10^7 M_\\odot$ BH accreting at $10^3$ Eddington. Therefore, energetically, the simulated jets are consistent with observations of the most powerful tidal disruption...

  5. DIAMONDS: A new Bayesian nested sampling tool

    E-Print Network [OSTI]

    Corsaro, Enrico

    2015-01-01

    In the context of high-quality asteroseismic data provided by the NASA Kepler mission, we developed a new code, termed Diamonds (high-DImensional And multi-MOdal NesteD Sampling), for fast Bayesian parameter estimation and model comparison by means of the Nested Sampling Monte Carlo (NSMC) algorithm, an efficient and powerful method very suitable for high-dimensional problems (like the peak bagging analysis of solar-like oscillations) and multi-modal problems (i.e. problems that show multiple solutions). We applied the code to the peak bagging analysis of solar-like oscillations observed in a challenging F-type star. By means of Diamonds one is able to detect the different backgrounds in the power spectrum of the star (e.g. stellar granulation and faculae activity) and to understand whether one or two oscillation peaks can be identified or not. In addition, we demonstrate a novel approach to peak bagging based on multimodality, which is able to reduce significantly the number of free parameters involved in th...

  6. Double bevel construction of a diamond anvil

    DOE Patents [OSTI]

    Moss, W.C.

    1987-02-06

    Use of double or multiple bevel culet geometry on a diamond anvil to provide increased sample pressure and stability for a given force applied to the diamond tables. 7 figs.

  7. Method of Forming Diamonds from Carbonaceous Material

    SciTech Connect (OSTI)

    Daulton, Tyrone; Lewis, Roy; Rehn, Lynn; Kirk, Marquis

    1999-11-30

    A method for producing diamonds is provided comprising exposing carbonaceous material to ion irradiation at ambient temperature and pressure.

  8. Method for forming diamonds from carbonaceous material

    DOE Patents [OSTI]

    Daulton, Tyrone (Slidell, LA); Lewis, Roy (Evanston, IL); Rehn, Lynn (LaGrange, IL); Kirk, Marquis (Hinsdale, IL)

    2001-01-01

    A method for producing diamonds is provided comprising exposing carbonaceous material to ion irradiation at ambient temperature and pressure.

  9. High-Current Cold Cathode Employing Diamond and Related Materials

    SciTech Connect (OSTI)

    Hirshfield, Jay L.

    2014-10-22

    The essence of this project was for diamond films to be deposited on cold cathodes to improve their emission properties. Films with varying morphology, composition, and size of the crystals were deposited and the emission properties of the cathodes that utilize such films were studied. The prototype cathodes fabricated by the methods developed during Phase I were tested and evaluated in an actual high-power RF device during Phase II. These high-power tests used the novel active RF pulse compression system and the X-band magnicon test facility at US Naval Research Laboratory. In earlier tests, plasma switches were employed, while tests under this project utilized electron-beam switching. The intense electron beams required in the switches were supplied from cold cathodes embodying diamond films with varying morphology, including uncoated molybdenum cathodes in the preliminary tests. Tests with uncoated molybdenum cathodes produced compressed X-band RF pulses with a peak power of 91 MW, and a maximum power gain of 16.5:1. Tests were also carried out with switches employing diamond coated cathodes. The pulse compressor was based on use of switches employing electron beam triggering to effect mode conversion. In experimental tests, the compressor produced 165 MW in a ~ 20 ns pulse at ~18× power gain and ~ 140 MW at ~ 16× power gain in a 16 ns pulse with a ~ 7 ns flat-top. In these tests, molybdenum blade cathodes with thin diamond coatings demonstrated good reproducible emission uniformity with a 100 kV, 100 ns high voltage pulse. The new compressor does not have the limitations of earlier types of active pulse compressors and can operate at significantly higher electric fields without breakdown.

  10. Diamond-silicon carbide composite

    DOE Patents [OSTI]

    Qian, Jiang; Zhao, Yusheng

    2006-06-13

    Fully dense, diamond-silicon carbide composites are prepared from ball-milled microcrystalline diamond/amorphous silicon powder mixture. The ball-milled powder is sintered (P=5–8 GPa, T=1400K–2300K) to form composites having high fracture toughness. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPa.dot.m1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness. X-ray diffraction patterns and Raman spectra indicate that amorphous silicon is partially transformed into nanocrystalline silicon at 5 GPa/873K, and nanocrystalline silicon carbide forms at higher temperatures.

  11. Method for machining steel with diamond tools

    DOE Patents [OSTI]

    Casstevens, J.M.

    1984-01-01

    The present invention is directed to a method for machine optical quality finishes and contour accuracies of workpieces of carbon-containing metals such as steel with diamond tooling. The wear rate of the diamond tooling is significantly reduced by saturating the atmosphere at the interface of the workpiece and the diamond tool with a gaseous hydrocarbon during the machining operation. The presence of the gaseous hydrocarbon effectively eliminates the deterioration of the diamond tool by inhibiting or preventing the conversion of the diamond carbon to graphite carbon at the point of contact between the cutting tool and the workpiece.

  12. Method for machining steel with diamond tools

    DOE Patents [OSTI]

    Casstevens, John M. (Greenville, TX)

    1986-01-01

    The present invention is directed to a method for machining optical quality inishes and contour accuracies of workpieces of carbon-containing metals such as steel with diamond tooling. The wear rate of the diamond tooling is significantly reduced by saturating the atmosphere at the interface of the workpiece and the diamond tool with a gaseous hydrocarbon during the machining operation. The presence of the gaseous hydrocarbon effectively eliminates the deterioration of the diamond tool by inhibiting or preventing the conversion of the diamond carbon to graphite carbon at the point of contact between the cutting tool and the workpiece.

  13. Diamond Power Infrastructure Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar2-0057-EA Jump to: navigation,Department ofEnergie Jump

  14. Black Holes In Astronomy Black Holes In Astronomy

    E-Print Network [OSTI]

    Wagner, Stephan

    Black Hole horizon static limit ergosphere radiation magnetic fields jet jet #12;Black-hole accretion with a central bulge. #12;Click to edit Master text styles Second level Third level Fourth level Fifth level Jets and lobes of Cygnus A Carilli et al. Supermassive black holes are the most powerful engines in the Universe

  15. EA-1795: Diamond Green Diesel Facility in Norco, LA | Department...

    Office of Environmental Management (EM)

    5: Diamond Green Diesel Facility in Norco, LA EA-1795: Diamond Green Diesel Facility in Norco, LA April 1, 2011 EA-1795: Final Environmental Assessment Loan Guarantee to Diamond...

  16. RELATIONSHIP BETWEEN THE KINETIC POWER AND BOLOMETRIC LUMINOSITY OF JETS: LIMITATION FROM BLACK HOLE X-RAY BINARIES, ACTIVE GALACTIC NUCLEI, AND GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Ma, Renyi; Hou, Shujin; Xie, Fu-Guo E-mail: fgxie@shao.ac.cn

    2014-01-01

    The correlation between the kinetic power P {sub jet} and intrinsic bolometric luminosity L {sub jet} of jets may reveal the underlying jet physics in various black hole systems. Based on the recent work by Nemmen et al., we re-investigate this correlation with additional sources of black hole X-ray binaries (BXBs) in hard/quiescent states and low-luminosity active galactic nuclei (LLAGNs). The new sample includes 29 sets of data from 7 BXBs and 20 LLAGNs, with P {sub jet} and L {sub jet} being derived from spectral modeling of the quasi-simultaneous multi-band spectra under the accretion jet scenario. Compared to previous works, the range of luminosity is now enlarged to more than 20 decades, i.e., from ?10{sup 31} erg s{sup –1} to ?10{sup 52} erg s{sup –1}, which allows for better constraining of the correlation. One notable result is that the jets in BXBs and LLAGNs almost follow the same P {sub jet}-L {sub jet} correlation that was obtained from blazars and gamma-ray bursts. The slope indices we derived are 1.03 ± 0.01 for the whole sample, 0.85 ± 0.06 for the BXB subsample, 0.71 ± 0.11 for the LLAGN subsample, and 1.01 ± 0.05 for the LLAGN-blazar subsample, respectively. The correlation index around unit implies the independence of jet efficiency on the luminosity or kinetic power. Our results may further support the hypothesis that similar physical processes exist in the jets of various black hole systems.

  17. Episodic jet power extracted from a spinning black hole surrounded by a neutrino-dominated accretion flow in gamma-ray bursts

    SciTech Connect (OSTI)

    Cao, Xinwu [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Liang, En-Wei [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning 530004 (China); Yuan, Ye-Fei, E-mail: cxw@shao.ac.cn, E-mail: lew@gxu.edu.cn, E-mail: yfyuan@ustc.edu.cn [Department of Astronomy, University of Sciences and Technology of China, Hefei, Anhui 230026 (China)

    2014-07-10

    It was suggested that the relativistic jets in gamma-ray bursts (GRBs) are powered via the Blandford-Znajek (BZ) mechanism or the annihilation of neutrinos and anti-neutrinos from a neutrino cooling-dominated accretion flow (NDAF). The advection and diffusion of the large-scale magnetic field of an NDAF is calculated, and the external magnetic field is found to be dragged inward efficiently by the accretion flow for a typical magnetic Prandtl number P{sub m}=?/??1. The maximal BZ jet power can be ?10{sup 53}-10{sup 54} erg s{sup –1} for an extreme Kerr black hole, if an external magnetic field with 10{sup 14} Gauss is advected by the NDAF. This is roughly consistent with the field strength of the disk formed after a tidal disrupted magnetar. The accretion flow near the black hole horizon is arrested by the magnetic field if the accretion rate is below than a critical value for a given external field. The arrested accretion flow fails to drag the field inward and the field strength decays, and then the accretion re-starts, which leads to oscillating accretion. The typical timescale of such episodic accretion is of an order of one second. This can qualitatively explain the observed oscillation in the soft extended emission of short-type GRBs.

  18. Diamonds are a Sun's Best Friend: Examining the Photoconductive Properties of Diamond to Improve TEC Efficiency

    E-Print Network [OSTI]

    Diamonds are a Sun's Best Friend: Examining the Photoconductive Properties of Diamond to Improve source in TEC devices by using the sun makes the device more efficient. This research has shown that diamond films are enhanced by photoconductivity. If the sun was used to drive a TEC device that uses

  19. Diamond-silicon carbide composite and method

    DOE Patents [OSTI]

    Zhao, Yusheng (Los Alamos, NM)

    2011-06-14

    Uniformly dense, diamond-silicon carbide composites having high hardness, high fracture toughness, and high thermal stability are prepared by consolidating a powder mixture of diamond and amorphous silicon. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPam.sup.1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness.

  20. Diamond turning machine controller implementation

    SciTech Connect (OSTI)

    Garrard, K.P.; Taylor, L.W.; Knight, B.F.; Fornaro, R.J.

    1988-12-01

    The standard controller for a Pnuemo ASG 2500 Diamond Turning Machine, an Allen Bradley 8200, has been replaced with a custom high-performance design. This controller consists of four major components. Axis position feedback information is provided by a Zygo Axiom 2/20 laser interferometer with 0.1 micro-inch resolution. Hardware interface logic couples the computers digital and analog I/O channels to the diamond turning machine`s analog motor controllers, the laser interferometer, and other machine status and control information. It also provides front panel switches for operator override of the computer controller and implement the emergency stop sequence. The remaining two components, the control computer hardware and software, are discussed in detail below.

  1. Diamond turning of thermoplastic polymers

    SciTech Connect (OSTI)

    Smith, E.; Scattergood, R.O.

    1988-12-01

    Single point diamond turning studies were made using a series of thermoplastic polymers with different glass transition temperatures. Variations in surface morphology and surface roughness were observed as a function of cutting speed. Lower glass transition temperatures facilitate smoother surface cuts and better surface finish. This can be attributed to the frictional heating that occurs during machining. Because of the very low glass transition temperatures in polymeric compared to inorganic glasses, the precision machining response can be very speed sensitive.

  2. Ultratough, Thermally Stable Polycrystalline Diamond/Silicon...

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

    novel diamond nanocomposites are anticipated to yield significant energy, carbon and cost savings from improved productivity (i.e., reduced total drilling time). Applications...

  3. Electromagnetic Radiation Hardness of Diamond Detectors

    E-Print Network [OSTI]

    T. Behnke; M. Doucet; N. Ghodbane; A. Imhof; C. Martinez; W. Zeuner

    2001-08-22

    The behavior of artificially grown CVD diamond films under intense electromagnetic radiation has been studied. The properties of irradiated diamond samples have been investigated using the method of thermally stimulated current and by studying their charge collection properties. Diamonds have been found to remain unaffected after doses of 6.8 MGy of 10 keV photons and 10 MGy of MeV-range photons. This observation makes diamond an attractive detector material for a calorimeter in the very forward region of the proposed TESLA detector.

  4. Superconducting nanowire single photon detector on diamond

    SciTech Connect (OSTI)

    Atikian, Haig A.; Burek, Michael J.; Choy, Jennifer T.; Lon?ar, Marko; Eftekharian, Amin; Jafari Salim, A.; Hamed Majedi, A.

    2014-03-24

    Superconducting nanowire single photon detectors are fabricated directly on diamond substrates and their optical and electrical properties are characterized. Dark count performance and photon count rates are measured at varying temperatures for 1310?nm and 632?nm photons. A multi-step diamond surface polishing procedure is reported, involving iterative reactive ion etching and mechanical polishing to create a suitable diamond surface for the deposition and patterning of thin film superconducting layers. Using this approach, diamond substrates with less than 300?pm Root Mean Square surface roughness are obtained.

  5. Fluorinated diamond bonded in fluorocarbon resin

    DOE Patents [OSTI]

    Taylor, Gene W. (Los Alamos, NM)

    1982-01-01

    By fluorinating diamond grit, the grit may be readily bonded into a fluorocarbon resin matrix. The matrix is formed by simple hot pressing techniques. Diamond grinding wheels may advantageously be manufactured using such a matrix. Teflon fluorocarbon resins are particularly well suited for using in forming the matrix.

  6. Energy Harvesting Diamond Channel with Energy Cooperation

    E-Print Network [OSTI]

    Ulukus, Sennur

    Energy Harvesting Diamond Channel with Energy Cooperation Berk Gurakan Sennur Ulukus Department@umd.edu Abstract--We consider the energy harvesting diamond channel, where the source and two relays harvest energy the option of wirelessly transferring some of its energy to the relays via energy cooperation. We find

  7. Double bevel construction of a diamond anvil

    DOE Patents [OSTI]

    Moss, W.C.

    1988-10-11

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached. 8 figs.

  8. Gravitational radiation from radial infall of a particle into a Schwarzschild black hole. A numerical study of the spectra, quasi-normal modes and power-law tails

    E-Print Network [OSTI]

    Ermis Mitsou

    2010-12-17

    The computation of the gravitational radiation emitted by a particle falling into a Schwarzschild black hole is a classic problem studied already in the 1970s. Here we present a detailed numerical analysis of the case of radial infall starting at infinity with no initial velocity. We compute the radiated waveforms, spectra and energies for multipoles up to l = 6, improving significantly on the numerical accuracy of existing results. This is done by integrating the Zerilli equation in the frequency domain using the Green's function method. The resulting wave exhibits a "ring-down" phase whose dominant contribution is a superposition of the quasi-normal modes of the black hole. The numerical accuracy allows us to recover the frequencies of these modes through a fit of that part of the wave. Comparing with direct computations of the quasi-normal modes we reach a \\sim 10^{-4} to \\sim 10^{-2} accuracy for the first two overtones of each multipole. Our numerical accuracy also allows us to display the power-law tail that the wave develops after the ring-down has been exponentially cut-off. The amplitude of this contribution is \\sim 10^2 to \\sim 10^3 times smaller than the typical scale of the wave.

  9. Black Diamond, Washington: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformationBio-Gas Technologies, LLCMichigan:

  10. Optimization of Acetylene Black Conductive Additive and Polyvinylidene Difluoride Composition for High Power Rechargeable Lithium-Ion Cells

    E-Print Network [OSTI]

    Liu, G.; Zheng, H.; Battaglia, V.S.; Simens, A.S.; Minor, A.M.; Song, X.

    2007-01-01

    7), A365 G. M. Ehrlich, Lithium-ion Batteries, 3rd ed ed. (High Power Rechargeable Lithium-Ion Cells G. Liu a,z , H.local environment. (A) lithium-ion mass transfer in the

  11. Site Characterization for CO{sub 2} Storage from Coal-fired Power Facilities in the Black Warrior Basin of Alabama

    SciTech Connect (OSTI)

    Clark, Peter; Pashin, Jack; Carlson, Eric; Goodliffe, Andrew; McIntyre-Redden, Marcella; Mann, Steven; Thompson, Mason

    2012-08-31

    Coal-fired power plants produce large quantities of carbon dioxide. In order to mitigate the greenhouse gas emissions from these power plants, it is necessary to separate and store the carbon dioxide. Saline formations provide a potential sink for carbon dioxide and delineating the capacity of the various known saline formations is a key part of building a storage inventory. As part of this effort, a project was undertaken to access the storage capacity of saline reservoirs in the Black Warrior Basin of Alabama. This basin has been a productive oil and gas reservoir that is well characterized to the west of the two major coal-fired power plants that are north of Birmingham. The saline zones were thought to extend as far east as the Sequatchie Anticline which is just east of the power plants. There is no oil or gas production in the area surrounding the power plants so little is known about the formations in that area. A geologic characterization well was drilled on the Gorgas Power Plant site, which is the farthest west of two power plants in the area. The well was planned to be drilled to approximately 8,000 feet, but drilling was halted at approximately 5,000 feet when a prolific freshwater zone was penetrated. During drilling, a complete set of cores through all of the potential injection zones and the seals above these zones were acquired. A complete set of openhole logs were run along with a vertical seismic profile (VSP). Before drilling started two approximately perpendicular seismic lines were run and later correlated with the VSP. While the zones that were expected were found at approximately the predicted depths, the zones that are typically saline through the reservoir were found to be saturated with a light crude oil. Unfortunately, both the porosity and permeability of these zones were small enough that no meaningful hydrocarbon production would be expected even with carbon dioxide flooding. iv While this part of the basin was found to be unsuitable for carbon dioxide injection, there is still a large storage capacity in the basin to the west of the power plants. It will, however, require pipeline construction to transport the carbon dioxide to the injection sites.

  12. Self-composite comprised of nanocrystalline diamond and a non-diamond component useful for thermoelectric applications

    DOE Patents [OSTI]

    Gruen, Dieter M.

    2012-09-04

    One provides nanocrystalline diamond material that comprises a plurality of substantially ordered diamond crystallites that are sized no larger than about 10 nanometers. One then disposes a non-diamond component within the nanocrystalline diamond material. By one approach this non-diamond component comprises an electrical conductor that is formed at the grain boundaries that separate the diamond crystallites from one another. The resultant nanowire is then able to exhibit a desired increase with respect to its ability to conduct electricity while also preserving the thermal conductivity behavior of the nanocrystalline diamond material.

  13. Self-composite comprised of nanocrystalline diamond and a non-diamond component useful for thermoelectric applications

    DOE Patents [OSTI]

    Gruen, Dieter M. (Downers Grove, IL)

    2009-08-11

    One provides nanocrystalline diamond material that comprises a plurality of substantially ordered diamond crystallites that are sized no larger than about 10 nanometers. One then disposes a non-diamond component within the nanocrystalline diamond material. By one approach this non-diamond component comprises an electrical conductor that is formed at the grain boundaries that separate the diamond crystallites from one another. The resultant nanowire is then able to exhibit a desired increase with respect to its ability to conduct electricity while also preserving the thermal conductivity behavior of the nanocrystalline diamond material.

  14. Photo-stimulated low electron temperature high current diamond film field emission cathode

    DOE Patents [OSTI]

    Shurter; Roger Philips (Los Alamos, NM), Devlin; David James (Santa Fe, NM), Moody; Nathan Andrew (Los Alamos, NM), Taccetti; Jose Martin (Santa Fe, NM), Russell; Steven John (Los Alamos, NM)

    2012-07-24

    An electron source includes a back contact surface having a means for attaching a power source to the back contact surface. The electron source also includes a layer comprising platinum in direct contact with the back contact surface, a composite layer of single-walled carbon nanotubes embedded in platinum in direct contact with the layer comprising platinum. The electron source also includes a nanocrystalline diamond layer in direct contact with the composite layer. The nanocrystalline diamond layer is doped with boron. A portion of the back contact surface is removed to reveal the underlying platinum. The electron source is contained in an evacuable container.

  15. Analysis of the spectroscopy of a hybrid system composed of a superconducting flux qubit and diamond NV centers

    E-Print Network [OSTI]

    H. Cai; Y. Matsuzaki; K. Kakuyanagi; H. Toida; X. Zhu; N. Mizuochi; K. Nemoto; K. Semba; W. J. Munro; S. Saito; H. Yamaguchi

    2015-05-28

    A hybrid system that combines the advantages of a superconducting flux qubit and an electron spin ensemble in diamond is one of the promising devices to realize quantum information processing. Exploring the properties of the superconductor diamond system is essential for the efficient use of this device. When we perform spectroscopy of this system, significant power broadening is observed. However, previous models to describe this system are known to be applicable only when the power broadening is negligible. Here, we construct a new approach to analyze this system with strong driving, and succeed to reproduce the spectrum with the power broadening. Our results provide an efficient way to analyze this hybrid system.

  16. First principles study of Fe in diamond: A diamond-based half metallic dilute magnetic semiconductor

    SciTech Connect (OSTI)

    Benecha, E. M.; Lombardi, E. B.

    2013-12-14

    Half-metallic ferromagnetic ordering in semiconductors, essential in the emerging field of spintronics for injection and transport of highly spin polarised currents, has up to now been considered mainly in III–V and II–VI materials. However, low Curie temperatures have limited implementation in room temperature device applications. We report ab initio Density Functional Theory calculations on the properties of Fe in diamond, considering the effects of lattice site, charge state, and Fermi level position. We show that the lattice sites and induced magnetic moments of Fe in diamond depend strongly on the Fermi level position and type of diamond co-doping, with Fe being energetically most favorable at the substitutional site in p-type and intrinsic diamond, while it is most stable at a divacancy site in n-type diamond. Fe induces spin polarized bands in the band gap, with strong hybridization between Fe-3d and C-2s,2p bands. We further consider Fe-Fe spin interactions in diamond and show that substitutional Fe{sup +1} in p-type diamond exhibits a half-metallic character, with a magnetic moment of 1.0??{sub B} per Fe atom and a large ferromagnetic stabilization energy of 33?meV, an order of magnitude larger than in other semiconductors, with correspondingly high Curie temperatures. These results, combined with diamond's unique properties, demonstrate that Fe doped p-type diamond is likely to be a highly suitable candidate material for spintronics applications.

  17. Amorphous Diamond MEMS and Sensors

    SciTech Connect (OSTI)

    SULLIVAN, JOHN P.; FRIEDMANN, THOMAS A.; ASHBY, CAROL I.; DE BOER, MAARTEN P.; SCHUBERT, W. KENT; SHUL, RANDY J.; HOHLFELDER, ROBERT J.; LAVAN, D.A.

    2002-06-01

    This report describes a new microsystems technology for the creation of microsensors and microelectromechanical systems (MEMS) using stress-free amorphous diamond (aD) films. Stress-free aD is a new material that has mechanical properties close to that of crystalline diamond, and the material is particularly promising for the development of high sensitivity microsensors and rugged and reliable MEMS. Some of the unique properties of aD include the ability to easily tailor film stress from compressive to slightly tensile, hardness and stiffness 80-90% that of crystalline diamond, very high wear resistance, a hydrophobic surface, extreme chemical inertness, chemical compatibility with silicon, controllable electrical conductivity from insulating to conducting, and biocompatibility. A variety of MEMS structures were fabricated from this material and evaluated. These structures included electrostatically-actuated comb drives, micro-tensile test structures, singly- and doubly-clamped beams, and friction and wear test structures. It was found that surface micromachined MEMS could be fabricated in this material easily and that the hydrophobic surface of the film enabled the release of structures without the need for special drying procedures or the use of applied hydrophobic coatings. Measurements using these structures revealed that aD has a Young's modulus of {approx}650 GPa, a tensile fracture strength of 8 GPa, and a fracture toughness of 8 MPa{center_dot}m {sup 1/2}. These results suggest that this material may be suitable in applications where stiction or wear is an issue. Flexural plate wave (FPW) microsensors were also fabricated from aD. These devices use membranes of aD as thin as {approx}100 nm. The performance of the aD FPW sensors was evaluated for the detection of volatile organic compounds using ethyl cellulose as the sensor coating. For comparable membrane thicknesses, the aD sensors showed better performance than silicon nitride based sensors. Greater than one order of magnitude increase in chemical sensitivity is expected through the use of ultra-thin aD membranes in the FPW sensor. The discoveries and development of the aD microsystems technology that were made in this project have led to new research projects in the areas of aD bioMEMS and aD radio frequency MEMS.

  18. Fabrication of layered self-standing diamond film by dc arc plasma jet chemical vapor deposition

    SciTech Connect (OSTI)

    Chen, G. C.; Dai, F. W.; Li, B.; Lan, H.; Askari, J.; Tang, W. Z.; Lu, F. X.

    2007-01-15

    Layered self-standing diamond films, consisting of an upper layer, buffer layer, and a lower layer, were fabricated by fluctuating the ratio of methane to hydrogen in high power dc arc plasma jet chemical vapor deposition. There were micrometer-sized columnar diamond crystalline grains in both upper layer and lower layer. The size of the columnar diamond crystalline grains was bigger in the upper layer than that in the lower layer. The orientation of the upper layer was (110), while it was (111) for the lower layer. Raman results showed that no sp{sup 3} peak shift was found in the upper layer, but it was found and blueshifted in the lower layer. This indicated that the internal stress within the film body could be tailored by this layered structure. The buffer layer with nanometer-sized diamond grains formed by secondary nucleation was necessary in order to form the layered film. Growth rate was over 10 {mu}m/h in layered self-standing diamond film fabrication.

  19. Effective placement of detectors at diamond interchanges 

    E-Print Network [OSTI]

    Prabhakar, Dayakar

    1994-01-01

    Most signalized interchanges in Texas are tight urban diamond interchanges of freeways having one-way frontage roads. At these interchanges, traffic actuated control with improper location of detectors may result in inefficient traffic operations...

  20. Diamond coated silicon field emitter array

    SciTech Connect (OSTI)

    S. Albin; W. Fu; A. Varghese; A. C. Lavarias; G. R. Myneni

    1999-07-01

    Diamond coated silicon tip arrays, with and without a self-aligned gate, were fabricated, and current-voltage characteristics of 400 tips were measured. Diamond films were grown uniformly on Si tips using microwave plasma after nucleation with 10 nm diamond suspension and substrate bias. An emission current of 57 ?A was obtained at 5 V from the ungated array tips separated from an anode at 2 ?m. In the case of the gated arrays with 1.5 ?m aperture, an emission current of 3.4 ?A was measured at a gate voltage of 80 V for an anode separation of 200 ?m. The turn-on voltages for these two types of devices were 0.2 and 40 V, respectively. Diamond coated Si tip arrays have potential applications in field emission based low voltage vacuum electronic devices and microsensors.

  1. In Situ Tribo-Electrochemical Characterization of Diamond-Containing Materials 

    E-Print Network [OSTI]

    Xiao, Huaping

    2014-07-31

    and the diamond surface. In the present research, the wear mechanism of diamond-reinforced composite has been demonstrated. The amorphization-wear process of diamond can be real-timely monitored using electrochemical approach. The frication force between diamond...

  2. Diamond film growth from fullerene precursors

    DOE Patents [OSTI]

    Gruen, D.M.; Liu, S.; Krauss, A.R.; Pan, X.

    1997-04-15

    A method and system are disclosed for manufacturing diamond film. The method involves forming a fullerene vapor, providing a noble gas stream and combining the gas with the fullerene vapor, passing the combined fullerene vapor and noble gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the fullerene and deposition of a diamond film on a substrate. 10 figs.

  3. Plasma spraying method for forming diamond and diamond-like coatings

    DOE Patents [OSTI]

    Holcombe, Cressie E. (Farragut, TN); Seals, Roland D. (Oak Ridge, TN); Price, R. Eugene (Knoxville, TN)

    1997-01-01

    A method and composition for the deposition of a thick layer (10) of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition (12) including at least glassy carbon is heated in a direct current plasma arc device to a selected temperature above the softening point, in an inert atmosphere, and is propelled to quickly quenched on a selected substrate (20). The softened or molten composition (18) crystallizes on the substrate (20) to form a thick deposition layer (10) comprising at least a diamond or diamond-like material. The selected composition (12) includes at least glassy carbon as a primary constituent (14) and may include at least one secondary constituent (16). Preferably, the secondary constituents (16) are selected from the group consisting of at least diamond powder, boron carbide (B.sub.4 C) powder and mixtures thereof.

  4. Plasma spraying method for forming diamond and diamond-like coatings

    DOE Patents [OSTI]

    Holcombe, C.E.; Seals, R.D.; Price, R.E.

    1997-06-03

    A method and composition is disclosed for the deposition of a thick layer of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition including at least glassy carbon is heated in a direct current plasma arc device to a selected temperature above the softening point, in an inert atmosphere, and is propelled to quickly quenched on a selected substrate. The softened or molten composition crystallizes on the substrate to form a thick deposition layer comprising at least a diamond or diamond-like material. The selected composition includes at least glassy carbon as a primary constituent and may include at least one secondary constituent. Preferably, the secondary constituents are selected from the group consisting of at least diamond powder, boron carbide (B{sub 4}C) powder and mixtures thereof. 9 figs.

  5. n-Type diamond and method for producing same

    DOE Patents [OSTI]

    Anderson, Richard J. (Oakland, CA)

    2002-01-01

    A new n-type semiconducting diamond is disclosed, which is doped with n-type dopant atoms. Such diamond is advantageously formed by chemical vapor deposition from a source gas mixture comprising a carbon source compound for the diamond, and a volatile hot wire filament for the n-type impurity species, so that the n-type impurity atoms are doped in the diamond during its formation. A corresponding chemical vapor deposition method of forming the n-type semiconducting diamond is disclosed. The n-type semiconducting diamond of the invention may be usefully employed in the formation of diamond-based transistor devices comprising pn diamond junctions, and in other microelectronic device applications.

  6. Sparkling Diamonds – Reducing High Energy in the Frozen North 

    E-Print Network [OSTI]

    Feldman, J.

    2007-01-01

    De Beers, the undisputed world leader in diamond mining, in a typically proactive approach, completed an energy review at the Snap Lake Diamond Mine in the Northwest Territories. What makes the approach unique is that the mine is still under...

  7. Study of Electron Transport and Amplification in Diamond

    SciTech Connect (OSTI)

    Muller, Erik M.; Ben-Zvi, Ilan

    2013-03-31

    As a successful completion of this award, my group has demonstrated world-leading electron gain from diamond for use in a diamond-amplified photocathode. Also, using high-resolution photoemission measurements we were able to uncover exciting new physics of the electron emission mechanisms from hydrogen terminated diamond. Our work, through the continued support of HEP, has resulted in a greater understanding of the diamond material science, including current limits, charge transport modeling, and spatial uniformity.

  8. Morphology of PolyethyleneCarbon Black Composites G. BEAUCAGE,1

    E-Print Network [OSTI]

    Beaucage, Gregory

    -ray scattering (SAXS) study of a conductive grade of carbon black and carbon black­polymer composites and a power-law scaling of polydispersity. One use of conductive black­polyethylene composites is in circuit(methyl methacrylate); carbon black; filler; composite; conductivity; percolation INTRODUCTION The morphology

  9. Vacancy induced structural changes in diamond.

    SciTech Connect (OSTI)

    Barnard, A.; Sternberg, M.; Univ. of Melbourne

    2008-01-01

    Although optically active defects in nanodiamond are being considered as candidates for optical labeling in biomedical applications, development in this area is being hindered the fact that suitable defects are rarely seen in diamond nanoparticles in the size regime required. These defects usually form as a complex with an impurity and a neutral of charged vacancy, so a measurable concentration of vacancy point defects is also necessary. Presented here are results of density functional tight binding computer simulations investigating the stability of vacancies in diamond nanoparticles with different surface structures. The results indicate that both neutral and charged vacancies alter the structure of as-grown diamond nanoparticles and are likely to diffuse out of the particle during synthesis or irradiation. We also find that suitable passivation of the particle may alleviate this problem, and hence facilitate the formation of defect complexes.

  10. Hydrogen-doped cubic diamond and the crystal structure of n-diamond Bin Wen a,b,

    E-Print Network [OSTI]

    Melnik, Roderick

    Hydrogen-doped cubic diamond and the crystal structure of n-diamond Bin Wen a,b, , Roderick Melnik. In particular, hydrogen concen- tration dependent elastic constants and lattice parameters for the H-doped diamond have been analyzed. Our results indicate that when the hydrogen concentration is less than 19 at

  11. Wear of diamond and diamondlike carbon films.

    SciTech Connect (OSTI)

    Erdemir, A.; Energy Technology

    2002-01-01

    Detailed tribological studies on diamond and diamond-like carbon (DLC) films have confirmed that these films are inherently self-lubricating and resistant to abrasive, adhesive and corrosive wear. Because of their high chemical inertness, they are also resistant to corrosion and oxidation (even at elevated temperatures). The combination of such exceptional qualities in these films makes them ideal for a wide range of demanding tribological applications (such as microelectromechanical systems, cutting tools, mechanical seals, magnetic hard disks, etc.). These films, available for more than three decades, have been used extensively for tooling and magnetic hard disk applications. Their potential in other application areas is currently being explored around the world. With the development of new and more robust deposition methods in recent years, it is envisioned that the production of high quality diamond and DLC films will become very cost effective and highly reliable for large-scale applications in the transportation and manufacturing sectors. In this paper, sliding wear mechanisms of diamond and DLC films will be presented. Specifically, it will be shown that, in general the wear of these films is extremely low (mainly because of their exceptional hardness and low friction characteristics). Specific test conditions established during each sliding test, however, may dramatically affect the wear performance of certain diamond and DLC films. One of the dominant wear mechanismsrelates to a phase transformation that is primarily the result of very high mechanical and thermal loadings of sliding contact interfaces. The transformation products (such as disordered graphite) trapped at the sliding interface may transfer to themating surface and significantly affect friction and wear. This paper describes, in terms of structural and fundamental tribological knowledge, the ideal film microstructures and chemistry, as well as operational conditions under which diamond and DLC films perform the best and provide superlow friction and wear properties in sliding tribological applications.

  12. Method of improving field emission characteristics of diamond thin films

    DOE Patents [OSTI]

    Krauss, Alan R. (Naperville, IL); Gruen, Dieter M. (Downer Grove, IL)

    1999-01-01

    A method of preparing diamond thin films with improved field emission properties. The method includes preparing a diamond thin film on a substrate, such as Mo, W, Si and Ni. An atmosphere of hydrogen (molecular or atomic) can be provided above the already deposited film to form absorbed hydrogen to reduce the work function and enhance field emission properties of the diamond film. In addition, hydrogen can be absorbed on intergranular surfaces to enhance electrical conductivity of the diamond film. The treated diamond film can be part of a microtip array in a flat panel display.

  13. Method of improving field emission characteristics of diamond thin films

    DOE Patents [OSTI]

    Krauss, A.R.; Gruen, D.M.

    1999-05-11

    A method of preparing diamond thin films with improved field emission properties is disclosed. The method includes preparing a diamond thin film on a substrate, such as Mo, W, Si and Ni. An atmosphere of hydrogen (molecular or atomic) can be provided above the already deposited film to form absorbed hydrogen to reduce the work function and enhance field emission properties of the diamond film. In addition, hydrogen can be absorbed on intergranular surfaces to enhance electrical conductivity of the diamond film. The treated diamond film can be part of a microtip array in a flat panel display. 3 figs.

  14. Spectroscopic analysis of H{sub 2}/CH{sub 4} microwave plasma and fast growth rate of diamond single crystal

    SciTech Connect (OSTI)

    Derkaoui, N.; Rond, C. Hassouni, K.; Gicquel, A.

    2014-06-21

    One of the best ways to increase the diamond growth rate is to couple high microwave power to the plasma. Indeed, increasing the power density leads to increase gas temperature the atomic hydrogen density in the plasma bulk, and to produce more hydrogen and methyl at the diamond surface. Experimental and numerical approaches were used to study the microwave plasma under high power densities conditions. Gas temperature was measured by optical emission spectroscopy and H-atom density using actinometry. CH{sub 3}-radical density was obtained using a 1D model that describes temperatures and plasma composition from the substrate to the top of the reactor. The results show that gas temperature in the plasma bulk, atomic hydrogen, and methyl densities at the diamond surface highly increase with the power density. As a consequence, measurements have shown that diamond growth rate also increases. At very high power density, we measured a growth rate of 40??m/h with an H-atom density of 5 × 10{sup 17} cm{sup ?3} which corresponds to a H{sub 2} dissociation rate higher than 50%. Finally, we have shown that the growth rate can be framed between a lower and an upper limit as a function depending only on the maximum of H-atom density measured or calculated in the plasma bulk. The results also demonstrated that increasing fresh CH{sub 4} by an appropriate injection into the boundary layer is a potential way to increase the diamond growth rates.

  15. Black hole Meissner effect and Blandford-Znajek jets

    E-Print Network [OSTI]

    Penna, Robert

    Spinning black holes tend to expel magnetic fields. In this way they are similar to superconductors. It has been a persistent concern that this black hole “Meissner effect” could quench jet power at high spins. This would ...

  16. Diamond Shaving of Contaminated Concrete Surfaces

    SciTech Connect (OSTI)

    Mullen, Lisa K.

    2008-01-15

    Decommissioning and decontamination of existing facilities presents technological challenges. One major challenge is the removal of surface contamination from concrete floors and walls while eliminating the spread of contamination and volumetric reduction of the waste stream. Numerous methods have been tried with a varying degree of success. Recent technology has made this goal achievable and has been used successfully. This new technology is the Diamond Floor Shaver and Diamond Wall shaver. The Diamond Floor Shaver is a self-propelled, walk behind machine that literally shaves the contaminated concrete surface to specified depths. This is accomplished by using a patented system of 100 dry cutting diamond blades with offset diamond segments that interlock to provide complete shaving of the concrete surface. Grooves are eliminated which allows for a direct frisk reading to analyze results. When attached to an appropriate size vacuum, the dust produced is 100% contained. Dust is collected in drums ready for disposition and disposal. The waste produced in shaving 7,500 square feet at 1/8 inch thickness would fill a single 55 gallon drum. Production is dependent on depth of shaving but averages 100 square feet per hour. The wall shaver uses the same patented diamond drum and blades but is hydraulically driven and is deployed using a robotic arm allowing its operation to be to totally remote. It can reach ceilings as high as 20 feet. Numerous small projects were successfully completed using this technology. Large scale deployment came in 2003. Bluegrass, in conjunction with Bartlett Services, deployed this technology to support decontamination activities for closing of the Rocky Flats nuclear weapons site. Up to six floor shavers and one wall shaver were deployed in buildings B371 and B374. These buildings had up to one half-inch, fixed plutonium and beryllium contamination. Hundred-thousands of square feet of floors and walls were shaved successfully to depths of up to one half inch. Decontamination efforts were so successful the balance of the buildings could be demolished using conventional methods. The shavers helped keep the project on schedule while the vacuum system eliminated the potential for contaminants becoming airborne.

  17. Method to fabricate micro and nano diamond devices

    DOE Patents [OSTI]

    Morales, Alfredo M; Anderson, Richard J; Yang, Nancy Y. C.; Skinner, Jack L; Rye, Michael J

    2014-10-07

    A method including forming a diamond material on the surface of a substrate; forming a first contact and a separate second contact; and patterning the diamond material to form a nanowire between the first contact and the second contact. An apparatus including a first contact and a separate second contact on a substrate; and a nanowire including a single crystalline or polycrystalline diamond material on the substrate and connected to each of the first contact and the second contact.

  18. Methane storage capabilities of diamond analogues

    SciTech Connect (OSTI)

    Haranczyk, M; Lin, LC; Lee, K; Martin, RL; Neaton, JB; Smit, B

    2013-01-01

    Methane can be an alternative fuel for vehicular usage provided that new porous materials are developed for its efficient adsorption-based storage. Herein, we search for materials for this application within the family of diamond analogues. We used density functional theory to investigate structures in which tetrahedral C atoms of diamond are separated by-CC-or-BN-groups, as well as ones involving substitution of tetrahedral C atoms with Si and Ge atoms. The adsorptive and diffusive properties of methane are studied using classical molecular simulations. Our results suggest that the all-carbon structure has the highest volumetric methane uptake of 280 VSTP/V at p = 35 bar and T = 298 K. However, it suffers from limited methane diffusion. Alternatively, the considered Si and Ge-containing analogies have fast diffusive properties but their adsorption is lower, ca. 172-179 VSTP/V, at the same conditions.

  19. Measurement of tool forces in diamond turning

    SciTech Connect (OSTI)

    Drescher, J.; Dow, T.A.

    1988-12-01

    A dynamometer has been designed and built to measure forces in diamond turning. The design includes a 3-component, piezoelectric transducer. Initial experiments with this dynamometer system included verification of its predicted dynamic characteristics as well as a detailed study of cutting parameters. Many cutting experiments have been conducted on OFHC Copper and 6061-T6 Aluminum. Tests have involved investigation of velocity effects, and the effects of depth and feedrate on tool forces. Velocity has been determined to have negligible effects between 4 and 21 m/s. Forces generally increase with increasing depth of cut. Increasing feedrate does not necessarily lead to higher forces. Results suggest that a simple model may not be sufficient to describe the forces produced in the diamond turning process.

  20. Precision diamond grinding of ceramics and glass

    SciTech Connect (OSTI)

    Smith, S.; Paul, H.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the effect of machine parameters and material properties on precision diamond grinding of ceramics and glass. The critical grinding depth to initiate the plastic flow-to-brittle fracture regime will be directly measured using plunge-grind tests. This information will be correlated with machine parameters such as wheel bonding and diamond grain size. Multiaxis grinding tests will then be made to provide data more closely coupled with production technology. One important aspect of the material property studies involves measuring fracture toughness at the very short crack sizes commensurate with grinding damage. Short crack toughness value`s can be much less than the long-crack toughness values measured in conventional fracture tests.

  1. Quantum black hole inflation

    E-Print Network [OSTI]

    M. B. Altaie

    2001-05-07

    In this paper we follow a new approach for particle creation by a localized strong gravitational field. The approach is based on a definition of the physical vacuum drawn from Heisenberg uncertainty principle. Using the fact that the gravitational field red-shifts the frequency modes of the vacuum, a condition on the minimum stregth of the gravitational field required to achieve real particle creation is derived. Application of this requirement on a Schwartzchid black hole resulted in deducing an upper limit on the region, outside the event horizon, where real particles can be created. Using this regional upper limit, and considering particle creation by black holes as a consequence of the Casimir effect, with the assumption that the created quanta are to be added to the initial energy, we deduce a natural power law for the development of the event horizon, and consequently a logarithmic law for the area spectrum of an inflating black hole. Application of the results on a cosmological model shows that if we start with a Planck-dimensional black hole, then through the process of particle creation we end up with a universe having the presently estimated critical density. Such a universe will be in a state of eternal inflation.

  2. Ultratough CVD single crystal diamond and three dimensional growth thereof

    DOE Patents [OSTI]

    Hemley, Russell J. (Washington, DC); Mao, Ho-kwang (Washington, DC); Yan, Chih-shiue (Washington, DC)

    2009-09-29

    The invention relates to a single-crystal diamond grown by microwave plasma chemical vapor deposition that has a toughness of at least about 30 MPa m.sup.1/2. The invention also relates to a method of producing a single-crystal diamond with a toughness of at least about 30 MPa m.sup.1/2. The invention further relates to a process for producing a single crystal CVD diamond in three dimensions on a single crystal diamond substrate.

  3. Robust Diamond-Based RF Switch Yields Enhanced Communication...

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

    diamond (UNCD) as a dielectric. A specialized radio frequency (RF) micro-electromechanical system (MEMS) switch that promises enhanced capabilities for next-generation...

  4. Synthesis and characterization of a nanocrystalline diamond aerogel

    E-Print Network [OSTI]

    Pauzauskie, Peter J.

    2012-01-01

    nanocrystalline diamond aerogel Peter J. Pauzauskie a,1,2 ,Laboratory, Berkeley, CA 94720 Aerogel materials have myriadcreating a nanodiamond aerogel matrix has remained an

  5. Substitutional Boron in Nanodiamond, Bucky-Diamond, and Nanocrystalline Diamond Grain Boundaries

    SciTech Connect (OSTI)

    Barnard, Amanda S.; Sternberg, Michael G.

    2006-10-05

    Although boron has been known for many years to be a successful dopant in bulk diamond, efficient doping of nanocrystalline diamond with boron is still being developed. In general, the location, configuration, and bonding structure of boron in nanodiamond is still unknown, including the fundamental question of whether it is located within grains or grain boundaries of thin films and whether it is within the core or at the surface of nanoparticles. Presented here are density functional tight-binding simulations examining the configuration, potential energy surface, and electronic charge of substitutional boron in various types of nanocrystalline diamond. The results predict that boron is likely to be positioned at the surface of isolated particles and at the grain boundary of thin-film samples.

  6. Proposal of room-temperature diamond maser

    E-Print Network [OSTI]

    Liang Jin; Matthias Pfänder; Nabeel Aslam; Sen Yang; Jörg Wrachtrup; Ren-Bao Liu

    2015-09-25

    Lasers have revolutionized optical science and technology, but their microwave counterpart, maser, has not realized its great potential due to its demanding work conditions (high-vacuum for gas maser and liquid-helium temperature for solid-state maser). Room-temperature solid-state maser is highly desirable, but under such conditions the lifetimes of emitters (usually electron spins) are usually too short (~ns) for population inversion. The only room-temperature solid-state maser is based on a pentacene-doped p-terphenyl crystal, which has long spin lifetime (~0.1 ms). This maser, however, operates only in the pulse mode and the material is unstable. Here we propose room-temperature maser based on nitrogen-vacancy (NV) centres in diamond, which feature long spin lifetimes at room temperature (~10 ms), high optical pump efficiency, and material stability. We demonstrate that under readily accessible conditions, room-temperature diamond maser is feasible. Room-temperature diamond maser may facilitate a broad range of microwave technologies.

  7. Patterning of nanocrystalline diamond films for diamond microstructures useful in MEMS and other devices

    DOE Patents [OSTI]

    Gruen, Dieter M. (Downers Grove, IL); Busmann, Hans-Gerd (Bremen, DE); Meyer, Eva-Maria (Bremen, DE); Auciello, Orlando (Bolingbrook, IL); Krauss, Alan R. (late of Naperville, IL); Krauss, Julie R. (Naperville, IL)

    2004-11-02

    MEMS structure and a method of fabricating them from ultrananocrystalline diamond films having average grain sizes of less than about 10 nm and feature resolution of less than about one micron . The MEMS structures are made by contacting carbon dimer species with an oxide substrate forming a carbide layer on the surface onto which ultrananocrystalline diamond having average grain sizes of less than about 10 nm is deposited. Thereafter, microfabrication process are used to form a structure of predetermined shape having a feature resolution of less than about one micron.

  8. Electrically conductive polycrystalline diamond and particulate metal based electrodes

    DOE Patents [OSTI]

    Swain, Greg M.; Wang, Jian

    2005-04-26

    An electrically conducting and dimensionally stable diamond (12, 14) and metal particle (13) electrode produced by electrodepositing the metal on the diamond is described. The electrode is particularly useful in harsh chemical environments and at high current densities and potentials. The electrode is particularly useful for generating hydrogen, and for reducing oxygen and oxidizing methanol in reactions which are of importance in fuel cells.

  9. CVD diamond: a new technology for the Paul W. May

    E-Print Network [OSTI]

    Bristol, University of

    , and as an insert and/or wear- resistant coating for cutting tools. Ob- viously, given its many unique properties polycrystalhne diamond films, or coatings, by a wide variety of chemical vapour Paul W. May, B.Sc., Ph.D. After and heat sinks, while the possibility of coating large surface areas with a continuous film of diamond

  10. Analyzing the performance of diamond-coated micro end mills.

    SciTech Connect (OSTI)

    Torres, C. D.; Heaney, P. J.; Sumant, A. V.; Hamilton, M. A.; Carpick, R. W.; Pfefferkorn, F. E.; Univ. of Wisconsin at Madison; Univ. of Pennsylvania

    2009-06-01

    A method is presented to improve the tool life and cutting performance of 300 {micro}m diameter tungsten carbide (WC) micro end mills by applying thin (<300 nm) fine-grained diamond (FGD) and nanocrystalline diamond (NCD) coatings using the hot-filament chemical vapor deposition (HF-CVD) process. The performance of the diamond-coated tools has been evaluated by comparing their performance in dry slot milling of 6061-T6 aluminum against uncoated WC micro end mills. Tool wear, coating integrity, and chip morphology were characterized using SEM and white light interferometry. The initial test results show a dramatic improvement in the tool integrity (i.e., corners not breaking off), a lower wear rate, no observable adhesion of aluminum to the diamond-coated tool, and a significant reduction in the cutting forces (>50%). Reduction of the cutting forces is attributed to the low friction and adhesion of the diamond coating. However, approximately 80% of the tools coated with the larger FGD coatings failed during testing due to delamination. Additional machining benefits were attained for the NCD films, which was obtained by using a higher nucleation density seeding process for diamond growth. This process allowed for thinner, smaller grained diamond coatings to be deposited on the micro end mills, and enabled continued operation of the tool even after the integrity of the diamond coating had been compromised. As opposed to the FGD-coated end mills, only 40% of the NCD-tools experienced delamination issues.

  11. Diamond and Related Materials 9 (2000) 12221227 www.elsevier.com/locate/diamond

    E-Print Network [OSTI]

    Bristol, University of

    2000-01-01

    have been deposited on Si substrates using CH 4 -based RF plasmas with addition of 0­21% PH 3; Diamond-like carbon; Field emission; Phosphorus doping 1. Introduction produced by a filtered cathodic arc and compatibility coupled radio frequency (RF) plasma deposition has been used to produce P-doped DLC films [9

  12. Method and apparatus for diamond wire cutting of metal structures

    DOE Patents [OSTI]

    Parsells, Robert; Gettelfinger, Geoff; Perry, Erik; Rule, Keith

    2005-04-19

    A method and apparatus for diamond wire cutting of metal structures, such as nuclear reactor vessels, is provided. A diamond wire saw having a plurality of diamond beads with beveled or chamfered edges is provided for sawing into the walls of the metal structure. The diamond wire is guided by a plurality of support structures allowing for a multitude of different cuts. The diamond wire is cleaned and cooled by CO.sub.2 during the cutting process to prevent breakage of the wire and provide efficient cutting. Concrete can be provided within the metal structure to enhance cutting efficiency and reduce airborne contaminants. The invention can be remotely controlled to reduce exposure of workers to radioactivity and other hazards.

  13. Observing bulk diamond spin coherence in high-purity nanodiamonds

    E-Print Network [OSTI]

    Helena S. Knowles; Dhiren M. Kara; Mete Atature

    2013-10-03

    Nitrogen-vacancy centres (NVs) in diamond are attractive for research straddling quantum information science and nanoscale magnetometry and thermometry. While ultrapure bulk diamond NVs sustain the longest spin coherence times among optically accessible spins, nanodiamond NVs display persistently poor spin coherence. Here we introduce high-purity nanodiamonds accommodating record-long NV coherence times, >60 us, observed via universal dynamical decoupling. We show that the main contribution to decoherence comes from nearby nitrogen impurities rather than surface states. We protect the NV spin free precession, essential to DC magnetometry, by driving solely these impurities into the motional narrowing regime. This extends the NV free induction decay time from 440 ns, longer than that in type Ib bulk diamond, to 1.27 us, which is comparable to that in type IIa (impurity-free) diamond. These properties allow the simultaneous exploitation of both high sensitivity and nanometre resolution in diamond-based emergent quantum technologies.

  14. Test of a prototype neutron spectrometer based on diamond detectors in a fast reactor

    E-Print Network [OSTI]

    M. Osipenko; F. Pompili; M. Ripani; M. Pillon; G. Ricco; B. Caiffi; R. Cardarelli; G. Verona-Rinati; S. Argiro

    2015-05-23

    A prototype of neutron spectrometer based on diamond detectors has been developed. This prototype consists of a $^6$Li neutron converter sandwiched between two CVD diamond crystals. The radiation hardness of the diamond crystals makes it suitable for applications in low power research reactors, while a low sensitivity to gamma rays and low leakage current of the detector permit to reach good energy resolution. A fast coincidence between two crystals is used to reject background. The detector was read out using two different electronic chains connected to it by a few meters of cable. The first chain was based on conventional charge-sensitive amplifiers, the other used a custom fast charge amplifier developed for this purpose. The prototype has been tested at various neutron sources and showed its practicability. In particular, the detector was calibrated in a TRIGA thermal reactor (LENA laboratory, University of Pavia) with neutron fluxes of $10^8$ n/cm$^2$s and at the 3 MeV D-D monochromatic neutron source named FNG (ENEA, Rome) with neutron fluxes of $10^6$ n/cm$^2$s. The neutron spectrum measurement was performed at the TAPIRO fast research reactor (ENEA, Casaccia) with fluxes of 10$^9$ n/cm$^2$s. The obtained spectra were compared to Monte Carlo simulations, modeling detector response with MCNP and Geant4.

  15. Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams

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

    Bang, W.; Albright, B. J.; Bradley, P. A.; Gautier, D. C.; Palaniyappan, S.; Vold, E. L.; Cordoba, M. A. Santiago; Hamilton, C. E.; Fernández, J. C.

    2015-09-22

    With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has beenmore »unavailable to date. We have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.« less

  16. JOURNAL OF MATERIALS SCIENCE 31 (1996) 2801 2805 Laser ablation of diamond fibres and a diamond fibre

    E-Print Network [OSTI]

    Bristol, University of

    1996-01-01

    ] and are also being considered for cutting tools [4]. A recent development has been the manufacture of diamond damage using conventional tools. The cutting and machining operations have therefore become a critical Research Agency Farnborough, GU14 6TD, UK Continuous chemical vapour-deposited diamond-coated fibres

  17. Diamond Shamrock nears completion of major expansions

    SciTech Connect (OSTI)

    True, W.R.

    1993-05-24

    With completion later this year of a second refined products line into Colorado, Diamond Shamrock Inc., San Antonio, will have added more than 600 miles of product and crude-oil pipeline on its system and expanded charge and production capacities at its two state-of-the-art refineries, all within 30 months. The projects aim at improving the company's ability to serve markets in the U.S. Southwest and increasing capacities and flexibility at its two refineries. The paper describes these projects under the following headings: new products service; another new line; and refineries, crude pipelines; Three Rivers expansion and Supplies for McKee.

  18. Diamond machine tool face lapping machine

    DOE Patents [OSTI]

    Yetter, H.H.

    1985-05-06

    An apparatus for shaping, sharpening and polishing diamond-tipped single-point machine tools. The isolation of a rotating grinding wheel from its driving apparatus using an air bearing and causing the tool to be shaped, polished or sharpened to be moved across the surface of the grinding wheel so that it does not remain at one radius for more than a single rotation of the grinding wheel has been found to readily result in machine tools of a quality which can only be obtained by the most tedious and costly processing procedures, and previously unattainable by simple lapping techniques.

  19. Diamond, Illinois: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, Alabama (UtilityInstrumentsArea (DOE GTP) Jump to:SouthBar, California:WalnutDiamond,

  20. Bruce Diamond | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouthReport for the t-) S/,,5 'a C | NationalBenefitsDiamond | National

  1. Hard, infrared black coating with very low outgassing

    SciTech Connect (OSTI)

    Kuzmenko, P J; Behne, D M; Casserly, T; Boardman, W; Upadhyaya, D; Boinapally, K; Gupta, M; Cao, Y

    2008-06-02

    Infrared astronomical instruments require absorptive coatings on internal surfaces to trap scattered and stray photons. This is typically accomplished with any one of a number of black paints. Although inexpensive and simple to apply, paint has several disadvantages. Painted surfaces can be fragile, prone to shedding particles, and difficult to clean. Most importantly, the vacuum performance is poor. Recently a plasma enhanced chemical vapor deposition (PECVD) process was developed to apply thick (30 {micro}m) diamond-like carbon (DLC) based protective coatings to the interior of oil pipelines. These DLC coatings show much promise as an infrared black for an ultra high vacuum environment. The coatings are very robust with excellent cryogenic adhesion. Their total infrared reflectivity of < 10% at normal incidence approaches that of black paints. We measured outgas rates of <10{sup -12} Torr liter/sec cm{sup 2}, comparable to bare stainless steel.

  2. Tensile properties of amorphous diamond films

    SciTech Connect (OSTI)

    Lavan, D.A.; Hohlfelder, R.J.; Sullivan, J.P.; Friedmann, T.A.; Mitchell, M.A.; Ashby, C.I.

    1999-12-02

    The strength and modulus of amorphous diamond, a new material for surface micromachined MEMS and sensors, was tested in uniaxial tension by pulling laterally with a flat tipped diamond in a nanoindenter. Several sample designs were attempted. Of those, only the single layer specimen with a 1 by 2 {micro}m gage cross section and a fixed end rigidly attached to the substrate was successful. Tensile load was calculated by resolving the measured lateral and normal forces into the applied tensile force and frictional losses. Displacement was corrected for machine compliance using the differential stiffness method. Post-mortem examination of the samples was performed to document the failure mode. The load-displacement data from those samples that failed in the gage section was converted to stress-strain curves using carefully measured gage cross section dimensions. Mean fracture strength was found to be 8.5 {+-} 1.4 GPa and the modulus was 831 {+-} 94 GPa. Tensile results are compared to hardness and modulus measurements made using a nanoindenter.

  3. Implantation conditions for diamond nanocrystal formation in amorphous silica

    SciTech Connect (OSTI)

    Buljan, Maja; Radovic, Iva Bogdanovic; Desnica, Uros V.; Ivanda, Mile; Jaksic, Milko; Saguy, Cecile; Kalish, Rafi; Djerdj, Igor; Tonejc, Andelka; Gamulin, Ozren

    2008-08-01

    We present a study of carbon ion implantation in amorphous silica, which, followed by annealing in a hydrogen-rich environment, leads to preferential formation of carbon nanocrystals with cubic diamond (c-diamond), face-centered cubic (n-diamond), or simple cubic (i-carbon) carbon crystal lattices. Two different annealing treatments were used: furnace annealing for 1 h and rapid thermal annealing for a brief period, which enables monitoring of early nucleation events. The influence of implanted dose and annealing type on carbon and hydrogen concentrations, clustering, and bonding were investigated. Rutherford backscattering, elastic recoil detection analysis, infrared spectroscopy, transmission electron microscopy, selected area electron diffraction, ultraviolet-visible absorption measurements, and Raman spectroscopy were used to study these carbon formations. These results, combined with the results of previous investigations on similar systems, show that preferential formation of different carbon phases (diamond, n-diamond, or i-carbon) depends on implantation energy, implantation dose, and annealing conditions. Diamond nanocrystals formed at a relatively low carbon volume density are achieved by deeper implantation and/or lower implanted dose. Higher volume densities led to n-diamond and finally to i-carbon crystal formation. This observed behavior is related to damage sites induced by implantation. The optical properties of different carbon nanocrystal phases were significantly different.

  4. The Nanoscience Beamline at Diamond, Optical Design Considerations

    SciTech Connect (OSTI)

    Reininger, Ruben; Dhesi, Sarnjeet

    2007-01-19

    The main requirement of the Nanoscience Beamline at Diamond is to deliver the highest possible flux at the sample position of a PEEM with a resolving power of about 5000 in the energy range 80-2000 eV. The source of the beamline is a couple of APPLE II helical undulators in tandem that can also be used separately to allow for faster switching of the circular polarization. Based on its versatility, a collimated plane grating monochromator using sagittally focusing elements was chosen to cover the required energy range with three gratings. The operation of this monochromator requires a collimated beam incident on the grating along the dispersion direction. This can be achieved either with a toroid, focusing with its major radius along the non-dispersive direction at the exit slit, or with a sagittal cylinder. The former option uses a sagittal cylinder after the grating to focus the collimated beam at the exit slit. In the latter case, a toroid after the grating is used to focus in both directions at the exit slit. The advantage of the toroid downstream the grating is the higher horizontal demagnification. This configuration fulfills the Nanoscience Beamline's required resolving power but cannot be used to achieve very high resolution due to the astigmatic coma aberration of the toroidal mirror. The focusing at the sample position is performed with a KB pair of plane elliptical mirrors. Assuming achievable values for the errors on all the optical surfaces, the expected spots FWHW in the horizontal and vertical directions are 10 {mu}m and 3 {mu}m, respectively. The calculated photon flux at this spot at 5000 resolving power is >1012 photons/sec between 80 and 1600 eV for linearly polarized light and between 106 and 1200 eV for circularly polarized light. The beamline is expected to be operational in January 2007.

  5. Del Black

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet HanfordDOEDanielDe novo Design ofDefects LeadDel Black Del

  6. Observation of diamond turned OFHC copper using Scanning Tunneling Microscopy

    SciTech Connect (OSTI)

    Grigg, D.A.; Russell, P.E.; Dow, T.A.

    1988-12-01

    Diamond turned OFHC copper samples have been observed within the past few months using the Scanning Tunneling Microscope. Initial results have shown evidence of artifacts which may be used to better understand the diamond turning process. The STM`s high resolution capability and three dimensional data representation allows observation and study of surface features unobtainable with conventional profilometry systems. Also, the STM offers a better quantitative means by which to analyze surface structures than the SEM. This paper discusses findings on several diamond turned OFHC copper samples having different cutting conditions. Each sample has been cross referenced using STM and SEM.

  7. Printable, flexible and stretchable diamond for thermal management

    DOE Patents [OSTI]

    Rogers, John A; Kim, Tae Ho; Choi, Won Mook; Kim, Dae Hyeong; Meitl, Matthew; Menard, Etienne; Carlisle, John

    2013-06-25

    Various heat-sinked components and methods of making heat-sinked components are disclosed where diamond in thermal contact with one or more heat-generating components are capable of dissipating heat, thereby providing thermally-regulated components. Thermally conductive diamond is provided in patterns capable of providing efficient and maximum heat transfer away from components that may be susceptible to damage by elevated temperatures. The devices and methods are used to cool flexible electronics, integrated circuits and other complex electronics that tend to generate significant heat. Also provided are methods of making printable diamond patterns that can be used in a range of devices and device components.

  8. Stokes--anti-Stokes Correlations in Raman Scattering from Diamond Membranes

    E-Print Network [OSTI]

    Kasperczyk, Mark; Neu, Elke; Maletinsky, Patrick; Novotny, Lukas

    2015-01-01

    We investigate the arrival statistics of Stokes (S) and anti-Stokes (aS) Raman photons generated in diamond membranes. Strong quantum correlations between the S and aS signals are observed, which implies that the two processes share the same phonon, that is, the phonon excited by the S process is consumed in the aS process. We show that the intensity cross-correlation $g_{\\rm S,aS}^{(2)}(0)$, which describes the simultaneous detection of Stokes and anti-Stokes photons, decreases steadily with laser power as $1/{\\rm P_L}$. Contrary to many other material systems, diamond exhibits a maximum $g_{\\rm S,aS}^{(2)}(0)$ at very low pump powers, implying that the Stokes-induced aS photons outnumber the thermally generated aS photons. On the other hand, the coincidence rate shows a quadratic plus cubic power dependence, which indicates a departure from the Stokes-induced anti-Stokes process.

  9. Energy Extraction from Spinning Black Holes via Relativistic Jets

    E-Print Network [OSTI]

    Ramesh Narayan; Jeffrey E. McClintock; Alexander Tchekhovskoy

    2013-03-12

    It has for long been an article of faith among astrophysicists that black hole spin energy is responsible for powering the relativistic jets seen in accreting black holes. Two recent advances have strengthened the case. First, numerical general relativistic magnetohydrodynamic simulations of accreting spinning black holes show that relativistic jets form spontaneously. In at least some cases, there is unambiguous evidence that much of the jet energy comes from the black hole, not the disk. Second, spin parameters of a number of accreting stellar-mass black holes have been measured. For ballistic jets from these systems, it is found that the radio luminosity of the jet correlates with the spin of the black hole. This suggests a causal relationship between black hole spin and jet power, presumably due to a generalized Penrose process.

  10. Substitutional Nitrogen in Nanodiamond and Bucky-Diamond Particles

    SciTech Connect (OSTI)

    Barnard, Amanda S.; Sternberg, Michael G.

    2005-09-15

    The inclusion of dopants (such as nitrogen) in diamond nanoparticles is expected to be important for use in future nanodevices, such as qubits for quantum computing. Although most commercial diamond nanoparticles contain a small fraction of nitrogen, it is still unclear whether it is located within the core or at the surface of the nanoparticle. Presented here are density functional tight binding simulations examining the configuration, potential energy surface, and electronic charge of substitutional nitrogen in nanodiamond and bucky-diamond particles. The results predict that nitrogen is likely to be positioned at the surface of both hydrogenated nanodiamond and (dehydrogenated) bucky-diamond, and that the coordination of the dopants within the particles is dependent upon the surface structure.

  11. Plasma-assisted conversion of solid hydrocarbon to diamond

    DOE Patents [OSTI]

    Valone, Steven M. (Santa Fe, NM); Pattillo, Stevan G. (Los Alamos, NM); Trkula, Mitchell (Los Alamos, NM); Coates, Don M. (Santa Fe, NM); Shah, S. Ismat (Wilmington, DE)

    1996-01-01

    A process of preparing diamond, e.g., diamond fiber, by subjecting a hydrocarbon material, e.g., a hydrocarbon fiber, to a plasma treatment in a gaseous feedstream for a sufficient period of time to form diamond, e.g., a diamond fiber is disclosed. The method generally further involves pretreating the hydrocarbon material prior to treatment with the plasma by heating within an oxygen-containing atmosphere at temperatures sufficient to increase crosslinking within said hydrocarbon material, but at temperatures insufficient to melt or decompose said hydrocarbon material, followed by heating at temperatures sufficient to promote outgassing of said crosslinked hydrocarbon material, but at temperatures insufficient to convert said hydrocarbon material to carbon.

  12. Pathogenesis of the Erythroid Failure in Diamond Blackfan Anemia

    E-Print Network [OSTI]

    Sieff, Colin A.

    Diamond Blackfan anaemia (DBA) is a severe congenital failure of erythropoiesis. Despite mutations in one of several ribosome protein genes, including RPS19, the cause of the erythroid specificity is still a mystery. We ...

  13. Ramp Compression of Diamond to 5 TPa: Experiments Taking Carbon...

    Office of Scientific and Technical Information (OSTI)

    Diamond to 5 TPa: Experiments Taking Carbon to the Thomas-Fermi-Dirac Regime Authors: Smith, R F ; Eggert, J H ; Jeanloz, R ; Duffy, T S ; Braun, D G ; Patterson, J R ; Rudd, R E...

  14. Yield Optimization of Nitrogen Vacancy Centers in Diamond 

    E-Print Network [OSTI]

    Chen, Jeson

    2012-10-19

    used in this work is Dynamitron electron beam particle accelerator (IBA Industrial, formerly Radiation Dynamics) capable of implantation energy from 300keV to 50MeV at Ruhr University at Bochum. Before ion implantation, diamonds...

  15. Robust Decoupling Techniques to Extend Quantum Coherence in Diamond

    E-Print Network [OSTI]

    Ryan, Colm A.

    We experimentally demonstrate over 2 orders of magnitude increase in the room-temperature coherence time of nitrogen-vacancy centers in diamond by implementing decoupling techniques. We show that equal pulse spacing ...

  16. Diamonds are an Electronic Device’s Best Friend

    Broader source: Energy.gov [DOE]

    Researchers at Argonne National Lab recently devised a way to use diamonds to brighten the performance of electronic devices, which could put a bit more sparkle in everyone’s day.

  17. Slip sliding away: Graphene and diamonds prove a slippery combination...

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

    Slip sliding away: Graphene and diamonds prove a slippery combination By Jared Sagoff * May 22, 2015 Tweet EmailPrint Scientists at the U.S. Department of Energy's Argonne National...

  18. Fluorinated diamond particles bonded in a filled fluorocarbon resin matrix

    DOE Patents [OSTI]

    Taylor, Gene W. (Los Alamos, NM); Roybal, Herman E. (Santa Fe, NM)

    1985-01-01

    A method of producing fluorinated diamond particles bonded in a filled fluorocarbon resin matrix. Simple hot pressing techniques permit the formation of such matrices from which diamond impregnated grinding tools and other articles of manufacture can be produced. Teflon fluorocarbon resins filled with Al.sub.2 O.sub.3 yield grinding tools with substantially improved work-to-wear ratios over grinding wheels known in the art.

  19. Fluorinated diamond particles bonded in a filled fluorocarbon resin matrix

    DOE Patents [OSTI]

    Taylor, G.W.; Roybal, H.E.

    1983-11-14

    A method of producing fluorinated diamond particles bonded in a filled fluorocarbon resin matrix. Simple hot pressing techniques permit the formation of such matrices from which diamond impregnated grinding tools and other articles of manufacture can be produced. Teflon fluorocarbon resins filled with Al/sub 2/O/sub 3/ yield grinding tools with substantially improved work-to-wear ratios over grinding wheels known in the art.

  20. Method for the preparation of nanocrystalline diamond thin films

    DOE Patents [OSTI]

    Gruen, D.M.; Krauss, A.R.

    1998-06-30

    A method and system are disclosed for manufacturing nanocrystalline diamond film on a substrate such as field emission tips. The method involves forming a carbonaceous vapor, providing a gas stream of argon, hydrocarbon and possibly hydrogen, and combining the gas with the carbonaceous vapor, passing the combined carbonaceous vapor and gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the carbonaceous vapor and deposition of a diamond film on the field emission tip. 40 figs.

  1. Analysis of the influence of tool dynamics in diamond turning

    SciTech Connect (OSTI)

    Fawcett, S.C.; Luttrell, D.E.; Keltie, R.F.

    1988-12-01

    This report describes the progress in defining the role of machine and interface dynamics on the surface finish in diamond turning. It contains a review of literature from conventional and diamond machining processes relating tool dynamics, material interactions and tool wear to surface finish. Data from experimental measurements of tool/work piece interface dynamics are presented as well as machine dynamics for the DTM at the Center.

  2. Diagnostic of fusion neutrons on JET tokamak using diamond detector

    SciTech Connect (OSTI)

    Nemtsev, G.; Amosov, V.; Marchenko, N.; Meshchaninov, S.; Rodionov, R.; Popovichev, S.; Collaboration: JET EFDA Conbributors

    2014-08-21

    In 2011-2012, an experimental campaign with a significant yield of fusion neutrons was carried out on the JET tokamak. During this campaign the facility was equipped with two diamond detectors based on natural and artificial CVD diamond. These detectors were designed and manufactured in State Research Center of Russian Federation TRINITI. The detectors measure the flux of fast neutrons with energies above 0.2 MeV. They have been installed in the torus hall and the distance from the center of plasma was about 3 m. For some of the JET pulses in this experiment, the neutron flux density corresponded to the operational conditions in collimator channels of ITER Vertical Neutron Camera. The main objective of diamond monitors was the measurement of total fast neutron flux at the detector location and the estimation of the JET total neutron yield. The detectors operate as threshold counters. Additionally a spectrometric measurement channel has been configured that allowed us to distinguish various energy components of the neutron spectrum. In this paper we describe the neutron signal measuring and calibration procedure of the diamond detector. Fluxes of DD and DT neutrons at the detector location were measured. It is shown that the signals of total neutron yield measured by the diamond detector correlate with signals measured by the main JET neutron diagnostic based on fission chambers with high accuracy. This experiment can be considered as a successful test of diamond detectors in ITER-like conditions.

  3. Thursday, February 28, 2013 Diamond Alumni Centre

    E-Print Network [OSTI]

    Kavanagh, Karen L.

    and University Awards Community and University Awards Dahabieh, Sam BC Hydro Power Smart Leadership Excellence

  4. Black Holes and Galaxy Dynamics

    E-Print Network [OSTI]

    David Merritt

    1999-06-02

    The consequences of nuclear black holes for the structure and dynamics of stellar spheroids are reviewed. Slow growth of a black hole in a pre-existing core produces a steep power-law density profile similar to the cusps seen in faint elliptical galaxies. The weaker cusps in bright ellipticals may result from ejection of stars by a coalescing black-hole binary; there is marginal kinematical evidence for such a process having occurred in M87. Stellar orbits in a triaxial nucleus are mostly regular at radii where the gravitational force is dominated by the black hole; however the orbital shapes are not conducive to reinforcing the triaxial figure, hence nuclei are likely to be approximately axisymmetric. In triaxial potentials, a ``zone of chaos'' extends outward to a radius where the enclosed stellar mass is roughly 100 times the mass of the black hole; in this chaotic zone, no regular, box-like orbits exist. At larger radii, the phase space in triaxial potentials is complex, consisting of stochastic orbits as well as regular orbits associated with stable resonances. Figure rotation tends to increase the degree of stochasticity. Both test-particle integrations and N-body simulations suggest that a triaxial galaxy responds globally to the presence of a central mass concentration by evolving toward more axisymmetric shapes; the evolution occurs rapidly when the mass of the central object exceeds roughly 2% of the mass in stars. The lack of significant triaxiality in most early-type galaxies may be a consequence of orbital evolution induced by nuclear black holes.

  5. Pulsed laser Raman spectroscopy in the laser-heated diamond anvil...

    Office of Scientific and Technical Information (OSTI)

    Pulsed laser Raman spectroscopy in the laser-heated diamond anvil cell Citation Details In-Document Search Title: Pulsed laser Raman spectroscopy in the laser-heated diamond anvil...

  6. Investigation of the Implementation of Ramp Reversal at a Diamond Interchange 

    E-Print Network [OSTI]

    Wang, Bo

    2013-06-25

    Diamond interchange design has been commonly utilized in United States to facilitate traffic exchange between freeway and frontage roads. Another less common interchange design is X-ramp interchange, which is the reversed version of diamond...

  7. The effects of diamond injector angles on flow structures at various Mach numbers 

    E-Print Network [OSTI]

    McLellan, Justin Walter

    2006-10-30

    Numerical simulations of a three dimensional diamond jet interaction flowfield at various diamond injector half angles into a supersonic crossflow were presented in this thesis. The numerical study was performed to improve the understanding...

  8. Electronic Structure of Diamond Surfaces Functionalized by Ru(tpy)2 Ioannis Zegkinoglou,,

    E-Print Network [OSTI]

    Himpsel, Franz J.

    in photocatalysis and photovoltaics, is compared to a hydrogen- terminated diamond surface as a reference. Bulk. The implications of using diamond films as inert electron donors in photocatalysis and dye-sensitized solar cells

  9. Two- and three-dimensional ultrananocrystalline diamond (UNCD) structures for a high resolution diamond-based MEMS technology.

    SciTech Connect (OSTI)

    Auciello, O.; Krauss, A. R.; Gruen, D. M.; Busmann, H. G.; Meyer, E. M.; Tucek, J.; Sumant, A.; Jayatissa, A.; Moldovan, N.; Mancini, D. C.; Gardos, M. N.

    2000-01-17

    Silicon is currently the most commonly used material for the fabrication of microelectromechanical systems (MEMS). However, silicon-based MEMS will not be suitable for long-endurance devices involving components rotating at high speed, where friction and wear need to be minimized, components such as 2-D cantilevers that may be subjected to very large flexural displacements, where stiction is a problem, or components that will be exposed to corrosive environments. The mechanical, thermal, chemical, and tribological properties of diamond make it an ideal material for the fabrication of long-endurance MEMS components. Cost-effective fabrication of these components could in principle be achieved by coating Si with diamond films and using conventional lithographic patterning methods in conjunction with e. g. sacrificial Ti or SiO{sub 2} layers. However, diamond coatings grown by conventional chemical vapor deposition (CVD) methods exhibit a coarse-grained structure that prevents high-resolution patterning, or a fine-grained microstructure with a significant amount of intergranular non-diamond carbon. The authors demonstrate here the fabrication of 2-D and 3-D phase-pure ultrananocrystalline diamond (UNCD) MEMS components by coating Si with UNCD films, coupled with lithographic patterning methods involving sacrificial release layers. UNCD films are grown by microwave plasma CVD using C{sub 60}-Ar or CH{sub 4}-Ar gas mixtures, which result in films that have 3--5 nm grain size, are 10--20 times smoother than conventionally grown diamond films, are extremely resistant to corrosive environments, and are predicted to have a brittle fracture strength similar to that of single crystal diamond.

  10. Heavy-ion irradiation induced diamond formation in carbonaceous materials.

    SciTech Connect (OSTI)

    Daulton, T. L.

    1999-01-08

    The basic mechanisms of metastable phase formation produced under highly non-equilibrium thermodynamic conditions within high-energy particle tracks are investigated. In particular, the possible formation of diamond by heavy-ion irradiation of graphite at ambient temperature is examined. This work was motivated, in part, by earlier studies which discovered nanometer-grain polycrystalline diamond aggregates of submicron-size in uranium-rich carbonaceous mineral assemblages of Precambrian age. It was proposed that the radioactive decay of uranium formed diamond in the fission particle tracks produced in the carbonaceous minerals. To test the hypothesis that nanodiamonds can form by ion irradiation, fine-grain polycrystalline graphite sheets were irradiated with 400 MeV Kr ions. The ion irradiated graphite (and unirradiated graphite control) were then subjected to acid dissolution treatments to remove the graphite and isolate any diamonds that were produced. The acid residues were then characterized by analytical and high-resolution transmission electron microscopy. The acid residues of the ion-irradiated graphite were found to contain ppm concentrations of nanodiamonds, suggesting that ion irradiation of bulk graphite at ambient temperature can produce diamond.

  11. Thermally stimulated exoelectronic emission of CVD diamond lms D. Brianda,*, P. Iacconia

    E-Print Network [OSTI]

    Bristol, University of

    Thermally stimulated exoelectronic emission of CVD diamond ®lms D. Brianda,*, P. Iacconia , M of several CVD diamond ®lms (undoped or doped with nitrogen) are studied by the thermally stimulated) ®lms, diamond is an attractive material in the ®eld of high temperature electronic applications [2

  12. Hydrogen Storage in Nano-Phase Diamond at High Temperature and Its Release

    SciTech Connect (OSTI)

    Tushar K Ghosh

    2008-10-13

    The objectives of this proposed research were: 91) Separation and storage of hydrogen on nanophase diamonds. It is expected that the produced hydrogen, which will be in a mixture, can be directed to a nanophase diamond system directly, which will not only store the hydrogen, but also separate it from the gas mixture, and (2) release of the stored hydrogen from the nanophase diamond.

  13. Electronic, Magnetic and Thermal Properties of Graphene-Diamond Hybrid S. Konabe,2, 3

    E-Print Network [OSTI]

    Maruyama, Shigeo

    of the graphene-diamond hybrid system. Energies are mea- sured from that of the Fermi level. Blue and redElectronic, Magnetic and Thermal Properties of Graphene-Diamond Hybrid Structure T. Shiga,1 S, it is demonstrated that the heat generated in the graphene nanoribbon can efficiently dissipate to the diamond region

  14. Field emission properties of phosphorus doped microwave plasma chemical vapor deposition diamond films by ion implantation

    E-Print Network [OSTI]

    Lee, Jong Duk

    to the conclusion that phosphorus ions and defects in the Si­diamond interface play an important role. INTRODUCTION A new mold type diamond field emission array FEA has been fabricated on indium tin oxide ITO defects induce the split energy bands within the wide band gap of diamond and help electrons to jump

  15. Synthesis and characterization of a nanocrystalline diamond aerogel

    SciTech Connect (OSTI)

    Pauzauskie, Peter J.; Crowhurst, Jonathan C.; Worsley, Marcus A.; Laurence, Ted A.; Kilcoyne, A. L. David; Wang, Yinmin; Willey, Trevor M.; Visbeck, Kenneth S.; Fakra, Sirine C.; Evans, William J.; Zaug, Joseph M.; Satcher, Jr., Joe H.

    2011-07-06

    Aerogel materials have myriad scientific and technological applications due to their large intrinsic surface areas and ultralow densities. However, creating a nanodiamond aerogel matrix has remained an outstanding and intriguing challenge. Here we report the high-pressure, high-temperature synthesis of a diamond aerogel from an amorphous carbon aerogel precursor using a laser-heated diamond anvil cell. Neon is used as a chemically inert, near-hydrostatic pressure medium that prevents collapse of the aerogel under pressure by conformally filling the aerogel's void volume. Electron and X-ray spectromicroscopy confirm the aerogel morphology and composition of the nanodiamond matrix. Time-resolved photoluminescence measurements of recovered material reveal the formation of both nitrogen- and silicon- vacancy point-defects, suggesting a broad range of applications for this nanocrystalline diamond aerogel.

  16. Plasma deposited diamond-like carbon films for large neutralarrays

    SciTech Connect (OSTI)

    Brown, I.G.; Blakely, E.A.; Bjornstad, K.A.; Galvin, J.E.; Monteiro, O.R.; Sangyuenyongpipat, S.

    2004-07-15

    To understand how large systems of neurons communicate, we need to develop methods for growing patterned networks of large numbers of neurons. We have found that diamond-like carbon thin films formed by energetic deposition from a filtered vacuum arc carbon plasma can serve as ''neuron friendly'' substrates for the growth of large neural arrays. Lithographic masks can be used to form patterns of diamond-like carbon, and regions of selective neuronal attachment can form patterned neural arrays. In the work described here, we used glass microscope slides as substrates on which diamond-like carbon was deposited. PC-12 rat neurons were then cultured on the treated substrates and cell growth monitored. Neuron growth showed excellent contrast, with prolific growth on the treated surfaces and very low growth on the untreated surfaces. Here we describe the vacuum arc plasma deposition technique employed, and summarize results demonstrating that the approach can be used to form large patterns of neurons.

  17. Subtractive 3D Printing of Optically Active Diamond Structures

    E-Print Network [OSTI]

    Martin, Aiden A; Aharonovich, Igor

    2014-01-01

    Diamond has recently attracted considerable attention as a promising platform for quantum technologies, photonics and high resolution sensing applications. Here we demonstrate a chemical approach that enables the fabrication of functional diamond structures using gas-mediated electron induced etching. The method achieves chemical etching at room temperature through the dissociation of surface-adsorbed H2O molecules by electron irradiation in a water vapor environment. High throughput, parallel processing is possible by electron flood exposure and the use of an etch mask, while single step, mask-free three dimensional fabrication and iterative editing are achieved using a variable pressure scanning electron microscope. The electron induced chemical etching paves the way to a transformative technology for nanofabrication of diamond and other wide band-gap semiconductors.

  18. Diamond-Silicon Carbide Composite And Method For Preparation Thereof

    DOE Patents [OSTI]

    Qian, Jiang (Los Alamos, NM); Zhao, Yusheng (Los Alamos, NM)

    2005-09-06

    Fully dense, diamond-silicon carbide composites are prepared from ball-milled microcrystalline diamond/amorphous silicon powder mixture. The ball-milled powder is sintered (P=5-8 GPa, T=1400K-2300K) to form composites having high fracture toughness. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPa.multidot.m.sup.1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness. X-ray diffraction patterns and Raman spectra indicate that amorphous silicon is partially transformed into nanocrystalline silicon at 5 GPa/873K, and nanocrystalline silicon carbide forms at higher temperatures.

  19. Smaller Footprint Drilling System for Deep and Hard Rock Environments; Feasibility of Ultra-High-Speed Diamond Drilling

    SciTech Connect (OSTI)

    TerraTek, A Schlumberger Company

    2008-12-31

    The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high rotational speeds (greater than 10,000 rpm). The work includes a feasibility of concept research effort aimed at development that will ultimately result in the ability to reliably drill 'faster and deeper' possibly with smaller, more mobile rigs. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration (ROP) rock cutting with substantially lower inputs of energy and loads. The significance of the 'ultra-high rotary speed drilling system' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm - usually well below 5,000 rpm. This document provides the progress through two phases of the program entitled 'Smaller Footprint Drilling System for Deep and Hard Rock Environments: Feasibility of Ultra-High-Speed Diamond Drilling' for the period starting 30 June 2003 and concluding 31 March 2009. The accomplishments of Phases 1 and 2 are summarized as follows: (1) TerraTek reviewed applicable literature and documentation and convened a project kick-off meeting with Industry Advisors in attendance (see Black and Judzis); (2) TerraTek designed and planned Phase I bench scale experiments (See Black and Judzis). Improvements were made to the loading mechanism and the rotational speed monitoring instrumentation. New drill bit designs were developed to provided a more consistent product with consistent performance. A test matrix for the final core bit testing program was completed; (3) TerraTek concluded small-scale cutting performance tests; (4) Analysis of Phase 1 data indicated that there is decreased specific energy as the rotational speed increases; (5) Technology transfer, as part of Phase 1, was accomplished with technical presentations to the industry (see Judzis, Boucher, McCammon, and Black); (6) TerraTek prepared a design concept for the high speed drilling test stand, which was planned around the proposed high speed mud motor concept. Alternative drives for the test stand were explored; a high speed hydraulic motor concept was finally used; (7) The high speed system was modified to accommodate larger drill bits than originally planned; (8) Prototype mud turbine motors and the high speed test stand were used to drive the drill bits at high speed; (9) Three different rock types were used during the testing: Sierra White granite, Crab Orchard sandstone, and Colton sandstone. The drill bits used included diamond impregnated bits, a polycrystalline diamond compact (PDC) bit, a thermally stable PDC (TSP) bit, and a hybrid TSP and natural diamond bit; and (10) The drill bits were run at rotary speeds up to 5500 rpm and weight on bit (WOB) to 8000 lbf. During Phase 2, the ROP as measured in depth of cut per bit revolution generally increased with increased WOB. The performance was mixed with increased rotary speed, with the depth cut with the impregnated drill bit generally increasing and the TSP and hybrid TSP drill bits generally decreasing. The ROP in ft/hr generally increased with all bits with increased WOB and rotary speed. The mechanical specific energy generally improved (decreased) with increased WOB and was mixed with increased rotary speed.

  20. Supermassive Black Holes

    E-Print Network [OSTI]

    Laura Ferrarese; David Merritt

    2002-06-13

    After a brief historical introduction, we summarize current efforts and accomplishments in the study of supermassive black holes.

  1. A diamond based neutron spectrometer for diagnostics of deuterium-tritium fusion plasmas

    SciTech Connect (OSTI)

    Cazzaniga, C., E-mail: carlo.cazzaniga@mib.infn.it; Nocente, M.; Gorini, G. [University of Milano Bicocca, Piazza della Scienza 3, Milano (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano (Italy); Rebai, M.; Giacomelli, L. [University of Milano Bicocca, Piazza della Scienza 3, Milano (Italy); Tardocchi, M.; Croci, G.; Grosso, G. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano (Italy); Calvani, P.; Girolami, M.; Trucchi, D. M. [CNR-ISM, Research Area Roma 1, Via Salaria km 29.300, 00015-Monterotondo Scalo (Rm) (Italy); Griesmayer, E. [Atominstitut, Vienna University of Technology, Vienna (Austria); Pillon, M. [Associazione EURATOM-ENEA sulla Fusione ENEA C.R. Frascati, Via E. Fermi, 45, 00044 Frascati (Roma) (Italy)

    2014-11-15

    Single crystal Diamond Detectors (SDD) are being increasingly exploited for neutron diagnostics in high power fusion devices, given their significant radiation hardness and high energy resolution capabilities. The geometrical efficiency of SDDs is limited by the size of commercially available crystals, which is often smaller than the dimension of neutron beams along collimated lines of sight in tokamak devices. In this work, we present the design and fabrication of a 14 MeV neutron spectrometer consisting of 12 diamond pixels arranged in a matrix, so to achieve an improved geometrical efficiency. Each pixel is equipped with an independent high voltage supply and read-out electronics optimized to combine high energy resolution and fast signals (<30 ns), which are essential to enable high counting rate (>1 MHz) spectroscopy. The response function of a prototype SDD to 14 MeV neutrons has been measured at the Frascati Neutron Generator by observation of the 8.3 MeV peak from the {sup 12}C(n, ?){sup 9}Be reaction occurring between neutrons and {sup 12}C nuclei in the detector. The measured energy resolution (2.5% FWHM) meets the requirements for neutron spectroscopy applications in deuterium-tritium plasmas.

  2. Fabrication of Diamond Nanowires for Quantum Information Processing Applications

    E-Print Network [OSTI]

    Birgit Hausmann; Mughees Khan; Tom Babinec; Yinan Zhang; Katie Martinick; Murray McCutcheon; Phil Hemmer; Marko Loncar

    2010-02-23

    We present a design and a top-down fabrication method for realizing diamond nanowires in both bulk single crystal and polycrystalline diamond. Numerical modeling was used to study coupling between a Nitrogen Vacancy (NV) color center and optical modes of a nanowire, and to find an optimal range of nanowire diameters that allows for large collection efficiency of emitted photons. Inductively coupled plasma (ICP) reactive ion etching (RIE) with oxygen is used to fabricate the nanowires. Drop-casted nanoparticles (including $\\mathrm{Au}$, $\\mathrm{SiO_{2}}$ and $\\mathrm{Al_2O_3}$) as well as electron beam lithography defined spin-on glass and evaporated $\\mathrm{Au}$ have been used as an etch mask. We found $\\mathrm{Al_2O_3}$ nanoparticles to be the most etch resistant. At the same time FOx e-beam resist (spin-on glass) proved to be a suitable etch mask for fabrication of ordered arrays of diamond nanowires. We were able to obtain nanowires with near vertical sidewalls in both polycrystalline and single crystal diamond. The heights and diameters of the polycrystalline nanowires presented in this paper are $\\unit[\\approx1]{\\mu m}$ and $\\unit[120-340]{nm}$, respectively, having a $\\unit[200]{nm/min}$ etch rate. In the case of single crystal diamond (types Ib and IIa) nanowires the height and diameter for different diamonds and masks shown in this paper were $\\unit[1-2.4]{\\mu m}$ and $\\unit[120-490]{nm}$ with etch rates between $\\unit[190-240]{nm/min}$.

  3. Classical and Quantum Chaos in the Diamond Shaped Billiard

    E-Print Network [OSTI]

    Salazar, R; Jaramillo, D; González, D L

    2012-01-01

    We analyse the classical and quantum behaviour of a particle trapped in a diamond shaped billiard. We defined this billiard as a half stadium connected with a triangular billiard. A parameter $\\xi$ which gradually change the shape of the billiard from a regular equilateral triangle ($\\xi=1$) to a diamond ($\\xi=0$) was used to control the transition between the regular and chaotic regimes. The classical behaviour is regular when the control parameter $\\xi$ is one; in contrast, the system is chaotic when $\\xi \

  4. Diamond turning of Si and Ge single crystals

    SciTech Connect (OSTI)

    Blake, P.; Scattergood, R.O.

    1988-12-01

    Single-point diamond turning studies have been completed on Si and Ge crystals. A new process model was developed for diamond turning which is based on a critical depth of cut for plastic flow-to-brittle fracture transitions. This concept, when combined with the actual machining geometry for single-point turning, predicts that {open_quotes}ductile{close_quotes} machining is a combined action of plasticity and fracture. Interrupted cutting experiments also provide a meant to directly measure the critical depth parameter for given machining conditions.

  5. Field emission properties of the polycrystalline diamond film prepared by microwave-assisted plasma chemical vapor deposition

    E-Print Network [OSTI]

    Lee, Jong Duk

    transparency. These properties allow diamond to be used in a few commercial products such as cutting tools, a patterned diamond nuclei is applied. For this, the substrate was coated with diamond photoresist DPR which is the normal photoresist containing 0.1 m diamond powders.7 Spin coated DPR can be patterned by using

  6. Magnetized static black Saturn

    E-Print Network [OSTI]

    Stoytcho S. Yazadjiev

    2008-02-06

    We construct a new static solution to the 5D Einstein-Maxwell equations describing a static black hole surrounded by a non-rotating dipole black ring. The configuration is kept in equilibrium by an external magnetic field interacting with the dipole charge of the black ring. The properties of the black Saturn-like configuration are studied and the basic physical quantities are calculated. The solution demonstrates 2-fold continuous non-uniqueness of the 5D magnetized static neutral black objects for fixed total mass and Melvin background.

  7. Quantum optics with nitrogen-vacancy centers in diamond

    E-Print Network [OSTI]

    Yiwen Chu; Mikhail D. Lukin

    2015-04-22

    We review the electronic level structure of the nitrogen-vacancy in diamond and some common experimental techniques to study its optical properties at low temperatures. We then summarize several recent experiments and advances in using nitrogen-vacancy centers for quantum optics.

  8. Single Crystal Diamond Beam Position Monitors with Radiofrequency Electronic Readout

    SciTech Connect (OSTI)

    Solar, B.; Graafsma, H.; Potdevin, G.; Trunk, U. [Hasylab, Deutsches Elektronen Synchroton, Hamburg (Germany); Morse, J.; Salome, M. [Instrumentation Services and Development Division, European Synchroton Radiation Facility, Grenoble (France)

    2010-06-23

    Over the energy range 5{approx}30 keV a suitably contacted, thin ({approx}100 {mu}m) diamond plate can be operated in situ as a continuous monitor of X-ray beam intensity and position as the diamond absorbs only a small percentage of the incident beam. Single crystal diamond is a completely homogeneous material showing fast (ns), spatially uniform signal response and negligible (diamond beam position monitors of simple quadrant electrode designs with metal contacts, operated using wideband electronic readout corresponding to the RF accelerator frequency. The instrumentation for these monitors must cover a large range of operating conditions: different beam sizes, fluxes, energies and time structure corresponding to the synchrotron fill patterns. Sophisticated new RF sampling electronics can satisfy most requirements: using a modified Libera Brilliance readout system, we measured the center of gravity position of a 25 {mu}m beam at the DORIS III F4 beam line at a rate of 130 Msample/s with narrowband filtering of a few MHz bandwidth. Digitally averaging the signal further provided a spatial resolution {approx}20 nm.

  9. Diamond Lattice Model of Semicrystalline Polyethylene in the Amorphous Region

    E-Print Network [OSTI]

    Diamond Lattice Model of Semicrystalline Polyethylene in the Amorphous Region Zhong­Hui Duan Abstract The statistics of polyethylene chains in the amorphous region between two crystallites have been as models of the chain molecules in the amorphous region of semicrystalline polyethylene, both

  10. Nanopatterning of ultrananocrystalline diamond thin films via block copolymer lithography.

    SciTech Connect (OSTI)

    Ramanathan, M.; Darling, S. B.; Sumant, A. V.; Auciello, O.

    2010-07-01

    Nanopatterning of diamond surfaces is critical for the development of diamond-based microelectromechanical system/nanoelectromechanical system (MEMS/NEMS), such as resonators or switches. Micro-/nanopatterning of diamond materials is typically done using photolithography or electron beam lithography combined with reactive ion etching (RIE). In this work, we demonstrate a simple process, block copolymer (BCP) lithography, for nanopatterning of ultrananocrystalline diamond (UNCD) films to produce nanostructures suitable for the fabrication of NEMS based on UNCD. In BCP lithography, nanoscale self-assembled polymeric domains serve as an etch mask for pattern transfer. The authors used thin films of a cylinder-forming organic-inorganic BCP, poly(styrene-block-ferrocenyldimethylsilane), PS-b-PFS, as an etch mask on the surface of UNCD films. Orientational control of the etch masking cylindrical PFS blocks is achieved by manipulating the polymer film thickness in concert with the annealing treatment. We have observed that the surface roughness of UNCD layers plays an important role in transferring the pattern. Oxygen RIE was used to etch the exposed areas of the UNCD film underneath the BCP. Arrays of both UNCD posts and wirelike structures have been created using the same starting polymeric materials as the etch mask.

  11. WATERJET ASSISTED POLYCRYSTALLINE DIAMOND INDENTATION DRILLING OF ROCK

    E-Print Network [OSTI]

    improved drilling rates can provide a significant benefit, justifying the costs and effort required both of drilling and completions of the wells can account for 25 ­ 50% of the cost of the electricity whichWATERJET ASSISTED POLYCRYSTALLINE DIAMOND INDENTATION DRILLING OF ROCK Santi, P, Bell, S

  12. Sun{diamond}Lab test facilities

    SciTech Connect (OSTI)

    Not Available

    1998-04-01

    This country`s efforts to successfully develop and commercialize concentrating solar power (CSP) technologies depend on specialized research and testing capabilities. To Support this effort, the US Department of Energy`s Concentrating Solar Power Program maintains two major test facilities: the National Solar Thermal Test Facility at Sandia National Laboratories in Albuquerque, New Mexico, and the High Flux Solar Furnace at the National Renewable Energy Laboratory in Golden, Colorado. These test facilities combine to be instrumental in the development of parabolic dishes, troughs, and solar power towers.

  13. Sun{diamond}Lab test facilities

    SciTech Connect (OSTI)

    1998-04-01

    This country's efforts to successfully develop and commercialize concentrating solar power (CSP) technologies depend on specialized research and testing capabilities. To Support this effort, the US Department of Energy's Concentrating Solar Power Program maintains two major test facilities: the National Solar Thermal Test Facility at Sandia National Laboratories in Albuquerque, New Mexico, and the High Flux Solar Furnace at the National Renewable Energy Laboratory in Golden, Colorado. These test facilities combine to be instrumental in the development of parabolic dishes, troughs, and solar power towers.

  14. Single crystal diamond detector measurements of deuterium-deuterium and deuterium-tritium neutrons in Joint European Torus fusion plasmas

    SciTech Connect (OSTI)

    Cazzaniga, C., E-mail: carlo.cazzaniga@mib.infn.it; Gorini, G.; Nocente, M. [Department of Physics “G. Occhialini,” University of Milano Bicocca, Piazza della Scienza 3, Milano (Italy) [Department of Physics “G. Occhialini,” University of Milano Bicocca, Piazza della Scienza 3, Milano (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano (Italy); Sundén, E. Andersson; Binda, F.; Ericsson, G. [Department of Physics and Astronomy, EURATOM-VR Association, Uppsala University, Uppsala (Sweden)] [Department of Physics and Astronomy, EURATOM-VR Association, Uppsala University, Uppsala (Sweden); Croci, G.; Grosso, G.; Cippo, E. Perelli; Tardocchi, M. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano (Italy)] [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano (Italy); Giacomelli, L.; Rebai, M. [Department of Physics “G. Occhialini,” University of Milano Bicocca, Piazza della Scienza 3, Milano (Italy)] [Department of Physics “G. Occhialini,” University of Milano Bicocca, Piazza della Scienza 3, Milano (Italy); Griesmayer, E. [Atominstitut, Vienna University of Technology (Austria)] [Atominstitut, Vienna University of Technology (Austria); Kaveney, G.; Syme, B. [Culham Centre for Fusion Energy, Culham OX143DB (United Kingdom)] [Culham Centre for Fusion Energy, Culham OX143DB (United Kingdom); Collaboration: JET-EFDA Contributors

    2014-04-15

    First simultaneous measurements of deuterium-deuterium (DD) and deuterium-tritium neutrons from deuterium plasmas using a Single crystal Diamond Detector are presented in this paper. The measurements were performed at JET with a dedicated electronic chain that combined high count rate capabilities and high energy resolution. The deposited energy spectrum from DD neutrons was successfully reproduced by means of Monte Carlo calculations of the detector response function and simulations of neutron emission from the plasma, including background contributions. The reported results are of relevance for the development of compact neutron detectors with spectroscopy capabilities for installation in camera systems of present and future high power fusion experiments.

  15. Resolving single molecule structures with nitrogen-vacancy centers in diamond

    E-Print Network [OSTI]

    Matthias Kost; Jianming Cai; Martin B. Plenio

    2014-07-23

    We present two-dimensional nuclear magnetic resonance spectroscopy protocols based on nitrogen-vacancy (NV) centers in diamond as efficient quantum sensors of protein structure. Continuous microwave driving fields are used to achieve Hartmann-Hahn resonances between NV spin sensor and proximate nuclei for selective control of nuclear spins and measurement of their polarization. Our protocols take advantage of the strong coupling between the NV sensor and the nuclei, thus facilitating coherence control of nuclear spins and relax the requirement of nuclear spin polarization. We dramatically reduce the experimental effort by employing a singular value thresholding matrix completion algorithm from signal processing to regain the resolution of protein structure based on sub-sampled data from NV based single molecule nuclear magnetic resonance spectroscopy. As an illustration, we demonstrate the power of this approach by identifying the nitrogen-Hydrogen interaction peak in an Alanine spectrum based on merely 5% of the sample data.

  16. Bicycling Black Rings

    E-Print Network [OSTI]

    Henriette Elvang; Maria J. Rodriguez

    2008-01-25

    We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

  17. Bicycling Black Rings

    E-Print Network [OSTI]

    Elvang, Henriette

    2008-01-01

    We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. Such limits exist for both types of solutions; for the bi-rings it is obtained when the two rings drag each other to extremality through the effect of gravitational frame-dragging. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

  18. Diamond origin and genesis: A C and N stable isotope study on diamonds from a single eclogitic xenolith (Kaalvallei, South Africa)

    E-Print Network [OSTI]

    Cartigny, Pierre

    aggregation state of 35 diamonds in a single eclogite xenolith from the Kaalvallei kimberlite in South Africa, and are positively correlated with nitrogen aggregation states which vary from 11.5% to 43.7% of IaB defects with diamond formation from recycled (crustal) material which is enriched in 15 N (i.e. positive 15 N

  19. BLACK HISTORY MONTH

    Broader source: Energy.gov [DOE]

    Black History Month is an annual celebration of achievements by black Americans and a time for recognizing the central role of African Americans in U.S. history. The event grew out of “Negro History Week,” created by historian Carter G. Woodson and other prominent African Americans. Other countries around the world, including Canada and the United Kingdom, also devote a month to celebrating black history.

  20. Diamond Wire Saw for Precision Machining of Laser Target Components

    SciTech Connect (OSTI)

    Bono, M J; Bennett, D W

    2005-08-08

    The fabrication of precision laser targets requires a wide variety of specialized mesoscale manufacturing techniques. The diamond wire saw developed in this study provides the capability to precisely section meso-scale workpieces mounted on the assembly stations used by the Target Fabrication Group. This new capability greatly simplifies the fabrication of many types of targets and reduces the time and cost required to build the targets. A variety of materials are used to fabricate targets, including metals, plastics with custom designed chemical formulas, and aerogels of various densities. The materials are usually provided in the form of small pieces or cast rods that must be machined to the required shape. Many of these materials, such as metals and some plastics, can be trimmed using a parting tool on a diamond turning machine. However, other materials, such as aerogels and brittle materials, cannot be adequately cut with a parting tool. In addition, the geometry of the parts often requires that the workpieces be held in a special assembly station, which excludes the use of a parting tool. In the past, these materials were sectioned using a small, handheld coping saw that used a diamond-impregnated wire as a blade. This miniature coping saw was effective, but it required several hours to cut through certain materials. Furthermore, the saw was guided by hand and often caused significant damage to fragile aerogels. To solve these problems, the diamond wire saw shown in Figure 1 was developed. The diamond wire saw is designed to machine through materials that are mounted in the Target Fabrication Group's benchtop assembly stations. These assembly stations are the primary means of aligning and assembling target components, and there is often a need to machine materials while they are mounted in the assembly stations. Unfortunately, commercially available saws are designed for very different applications and are far too large to be used with the assembly stations. Therefore, a custom diamond wire saw was designed and constructed. The diamond wire saw cuts through workpieces using a continuous loop of diamond-impregnated wire of length 840 mm. The wire loop runs around several idler pulleys and is driven by a simple geared DC motor that rotates at 17 rpm. The linear speed of the wire is 107 inches/minute. The saw is oriented at an angle of 20{sup o} from horizontal, so the operator can view the wire through the cutout at the front end of the saw. When looking through a microscope or camera with a horizontal line of sight, the operator can clearly see the wire as it cuts through the workpiece, as shown in the right side of Figure 1. The saw is mounted on a two-axis stage that allows the operator to align the wire with the workpiece. To cut through the workpiece, the operator drives the wire through the workpiece by turning the feed micrometer. An image of the interior of the diamond wire saw appears in Figure 2. This picture was taken after removing the protective cover plate from the saw.

  1. Accreting Black Holes

    E-Print Network [OSTI]

    Begelman, Mitchell C

    2014-01-01

    I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these interactions. Larger global magnetohydrodynamic simulations as well as simulations incorporating plasma microphysics and full radiation hydrodynamics will be needed to unravel some of the current mysteries of black hole accretion.

  2. Chaos anti-synchronization in multiple time delay power systems

    E-Print Network [OSTI]

    Elman Shahverdiev

    2015-09-20

    We elucidate conditions for chaos anti-synchronization between two uni-directionally coupled multiple time delay power systems. The results are of some importance to prevent power black-out in the entire power grid.

  3. Process for making a cesiated diamond film field emitter and field emitter formed therefrom

    DOE Patents [OSTI]

    Anderson, David F. (Batavia, IL); Kwan, Simon W. (Geneva, IL)

    1999-01-01

    A process for making a cesiated diamond film comprises (a) depositing a quantity of cesium iodide on the diamond film in a vacuum of between about 10.sup.-4 Torr and about 10.sup.-7 Torr, (b) increasing the vacuum to at least about 10.sup.-8 Torr, and (c) imposing an electron beam upon the diamond film, said electron beam having an energy sufficient to dissociate said cesium iodide and to incorporate cesium into interstices of the diamond film. The cesiated diamond film prepared according to the process has an operating voltage that is reduced by a factor of at least approximately 2.5 relative to conventional, non-cesiated diamond film field emitters.

  4. Process for making a cesiated diamond film field emitter and field emitter formed therefrom

    DOE Patents [OSTI]

    Anderson, D.F.; Kwan, S.W.

    1999-03-30

    A process for making a cesiated diamond film comprises (a) depositing a quantity of cesium iodide on the diamond film in a vacuum of between about 10{sup {minus}4} Torr and about 10{sup {minus}7} Torr, (b) increasing the vacuum to at least about 10{sup {minus}8} Torr, and (c) imposing an electron beam upon the diamond film, said electron beam having an energy sufficient to dissociate said cesium iodide and to incorporate cesium into interstices of the diamond film. The cesiated diamond film prepared according to the process has an operating voltage that is reduced by a factor of at least approximately 2.5 relative to conventional, non-cesiated diamond film field emitters. 2 figs.

  5. Superconducting single photon detectors integrated with diamond nanophotonic circuits

    E-Print Network [OSTI]

    Rath, Patrik; Ferrari, Simone; Sproll, Fabian; Lewes-Malandrakis, Georgia; Brink, Dietmar; Ilin, Konstantin; Siegel, Michael; Nebel, Christoph; Pernice, Wolfram

    2015-01-01

    Photonic quantum technologies promise to repeat the success of integrated nanophotonic circuits in non-classical applications. Using linear optical elements, quantum optical computations can be performed with integrated optical circuits and thus allow for overcoming existing limitations in terms of scalability. Besides passive optical devices for realizing photonic quantum gates, active elements such as single photon sources and single photon detectors are essential ingredients for future optical quantum circuits. Material systems which allow for the monolithic integration of all components are particularly attractive, including III-V semiconductors, silicon and also diamond. Here we demonstrate nanophotonic integrated circuits made from high quality polycrystalline diamond thin films in combination with on-chip single photon detectors. Using superconducting nanowires coupled evanescently to travelling waves we achieve high detection efficiencies up to 66 % combined with low dark count rates and timing resolu...

  6. Method for producing fluorinated diamond-like carbon films

    DOE Patents [OSTI]

    Hakovirta, Marko J.; Nastasi, Michael A.; Lee, Deok-Hyung; He, Xiao-Ming

    2003-06-03

    Fluorinated, diamond-like carbon (F-DLC) films are produced by a pulsed, glow-discharge plasma immersion ion processing procedure. The pulsed, glow-discharge plasma was generated at a pressure of 1 Pa from an acetylene (C.sub.2 H.sub.2) and hexafluoroethane (C.sub.2 F.sub.6) gas mixture, and the fluorinated, diamond-like carbon films were deposited on silicon <100>substrates. The film hardness and wear resistance were found to be strongly dependent on the fluorine content incorporated into the coatings. The hardness of the F-DLC films was found to decrease considerably when the fluorine content in the coatings reached about 20%. The contact angle of water on the F-DLC coatings was found to increase with increasing film fluorine content and to saturate at a level characteristic of polytetrafluoroethylene.

  7. Diamond neutral particle spectrometer for fusion reactor ITER

    SciTech Connect (OSTI)

    Krasilnikov, V.; Amosov, V.; Kaschuck, Yu.; Skopintsev, D. [Institution PROJECT CENTER ITER, 1, Akademik Kurchatov Sq., Moscow (Russian Federation)

    2014-08-21

    A compact diamond neutral particle spectrometer with digital signal processing has been developed for fast charge-exchange atoms and neutrons measurements at ITER fusion reactor conditions. This spectrometer will play supplementary role for Neutral Particle Analyzer providing 10 ms time and 30 keV energy resolutions for fast particle spectra in non-tritium ITER phase. These data will also be implemented for independent studies of fast ions distribution function evolution in various plasma scenarios with the formation of a single fraction of high-energy ions. In tritium ITER phase the DNPS will measure 14 MeV neutrons spectra. The spectrometer with digital signal processing can operate at peak counting rates reaching a value of 10{sup 6} cps. Diamond neutral particle spectrometer is applicable to future fusion reactors due to its high radiation hardness, fast response and high energy resolution.

  8. Rotating Hairy Black Holes

    E-Print Network [OSTI]

    B. Kleihaus; J. Kunz

    2000-12-20

    We construct stationary black holes in SU(2) Einstein-Yang-Mills theory, which carry angular momentum and electric charge. Possessing non-trivial non-abelian magnetic fields outside their regular event horizon, they represent non-perturbative rotating hairy black holes.

  9. Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)

    E-Print Network [OSTI]

    Sideras-Haddad, E.

    2009-01-01

    diamond-like structures (nanodiamond) observed using Ramandefect centres 21 in a nanodiamond matrix. II. Experimentallike structures (nanodiamond). Here the surface treatment

  10. "Hybrid" Black Holes

    E-Print Network [OSTI]

    Valeri P. Frolov; Andrei V. Frolov

    2014-12-30

    We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. For this purpose we use the formalism of massive thin null shells. The corresponding solution is called a "hybrid" black hole. The massive null shell has an angular momentum which is the origin of the rotation of the external Kerr spacetime. At the same time, the shell distorts the geometry inside the horizon. The inner geometry of the "hybrid" black hole coincides with the geometry of the interior of a non-rotating Weyl-distorted black hole. Properties of the "hybrid" black holes are briefly discussed.

  11. Simulation of ultraviolet- and soft X-ray-pulse generation as a result of cooperative recombination of excitons in diamond nanocrystals embedded in a polymer film

    SciTech Connect (OSTI)

    Kukushkin, V. A., E-mail: vakuk@appl.sci-nnov.ru [Russian Academy of Sciences, Institute for Applied Physics (Russian Federation)

    2013-11-15

    Using numerical simulation, it is shown that the recombination of free excitons photoexcited in diamond nanocrystals embedded in a polymer film can occur in the cooperative mode. It is found that this mode can be implemented despite the fact that diamond is an 'indirect' semiconductor. It is shown that the power of the generated radiation at the pulse peak during the cooperative recombination of free excitons can exceed that of the incoherent spontaneous emission of the same initial number of free excitons by more than an order of magnitude. Finally, it is shown that the process under consideration can be used to generate picosecond pulses of ultraviolet and soft X-ray electromagnetic field at a wavelength of 235 nm.

  12. Amorphous Diamond Flat Panel Displays - Final Report of ER-LTR CRADA project with SI Diamond Technology

    SciTech Connect (OSTI)

    Ager III, Joel W.

    1998-05-08

    The objective of this project was to determine why diamond-based films are unusually efficient electron emitters (field emission cathodes) at room temperature. Efficient cathodes based on diamond are being developed by SI Diamond Technology (SIDT) as components for bright, sunlight-readable, flat panel displays. When the project started, it was known that only a small fraction (<1%) of the cathode area is active in electron emission and that the emission sites themselves are sub-micron in size. The critical challenge of this project was to develop new microcharacterization methods capable of examining known emission sites. The research team used a combination of cathode emission imaging (developed at SIDT), micro-Raman spectroscopy (LBNL), and electron microscopy and spectroscopy (National Center for Electron Microscopy, LBNL) to examine the properties of known emission sites. The most significant accomplishment of the project was the development at LBNL of a very high resolution scanning probe that, for the first time, measured simultaneously the topography and electrical characteristics of single emission sites. The increased understanding of the emission mechanism helped SIDT to develop a new cathode material,''nano-diamond,'' which they have incorporated into their Field Emission Picture Element (FEPix) product. SIDT is developing large-format flat panel displays based on these picture elements that will be brighter and more efficient than existing outdoor displays such as Jumbotrons. The energy saving that will be realized if field emission displays are introduced commercially is in line with the energy conservation mission of DOE. The unique characterization tools developed in this project (particularly the new scanning microscopy method) are being used in ongoing BES-funded basic research.

  13. Diamond Energy Pty Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower VenturesInformation9)ask queries TypeDeveloper|Winds Wind FarmEnergy

  14. Diamond Willow Extension | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower VenturesInformation9)ask queries TypeDeveloper|Winds Wind

  15. PURDUE UNIVERSITY BLACK CULTURAL CENTER

    E-Print Network [OSTI]

    Pittendrigh, Barry

    traveled to Detroit, Michigan to study our fall research theme, " Black Detroit: The History, Movement

  16. Black Holes and Galaxy Evolution

    E-Print Network [OSTI]

    David Merritt

    1999-10-29

    Supermassive binary black holes and their influence on the structure and evolution of galaxies is reviewed.

  17. Plasma-activated direct bonding of diamond-on-insulator wafers to thermal oxide grown silicon wafers

    E-Print Network [OSTI]

    Akin, Tayfun

    Plasma-activated direct bonding of diamond-on-insulator wafers to thermal oxide grown silicon microscopy, profilometer and wafer bow measurements. Plasma-activated direct bonding of DOI wafers to thermal September 2010 Keywords: Diamond-on-insulator Plasma activation Ultrananocrystalline diamond Direct bonding

  18. University of Alberta opens new diamond lab Updated: November 27, 2013 | 7:58 pm | By Ryan Tumilty Metro Edmonton

    E-Print Network [OSTI]

    Machel, Hans

    University of Alberta opens new diamond lab Updated: November 27, 2013 | 7:58 pm | By Ryan Tumilty Siemens) If diamonds truly are a girl's best friend than a new lab at the University of Alberta could." Source: http://metronews.ca/news/edmonton/868068/university-of-alberta-opens-new-diamond-lab/ #12;

  19. Method of bonding diamonds in a matrix and articles thus produced

    DOE Patents [OSTI]

    Taylor, G.W.

    1981-01-27

    By fluorinating diamond grit, the grit may be readily bonded into a fluorocarbon resin matrix. The matrix is formed by simple hot pressing techniques. Diamond grinding wheels may advantageously be manufactured using such a matrix. Teflon fluorocarbon resins are particularly well suited for using in forming the matrix.

  20. Atmospheric plasma deposition of diamond-like carbon coatings Angela M. Ladwig a,b,

    E-Print Network [OSTI]

    Hicks, Robert F.

    include ion beam deposition, cathodic arc spray, pulsed laser ablation, argon ion sputtering, and plasmaAtmospheric plasma deposition of diamond-like carbon coatings Angela M. Ladwig a,b, , Ronald D Available online xxxx Keywords: Atmospheric pressure plasma Diamond-like carbon deposition DLC PECVD

  1. Thermal conductivity changes upon neutron transmutation of {sup 10}B doped diamond

    SciTech Connect (OSTI)

    Jagannadham, K., E-mail: jag-kasichainula@ncsu.edu [Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Verghese, K. [Nuclear Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Butler, J. E. [Code 6174, Naval research Laboratory, Washington, District of Columbia 20375 (United States)

    2014-08-28

    {sup 10}B doped p-type diamond samples were subjected to neutron transmutation reaction using thermal neutron flux of 0.9 × 10{sup 13} cm{sup ?2} s{sup ?1} and fast neutron flux of 0.09 × 10{sup 13} cm{sup ?2} s{sup ?1}. Another sample of epilayer grown on type IIa (110) single crystal diamond substrate was subjected to equal thermal and fast neutron flux of 10{sup 14}?cm{sup ?2} s{sup ?1}. The defects in the diamond samples were previously characterized by different methods. In the present work, thermal conductivity of these diamond samples was determined at room temperature by transient thermoreflectance method. The thermal conductivity change in the samples as a function of neutron fluence is explained by the phonon scattering from the point defects and disordered regions. The thermal conductivity of the diamond samples decreased more rapidly initially and less rapidly for larger neutron fluence. In addition, the thermal conductivity in type IIb diamond decreased less rapidly with thermal neutron fluence compared to the decrease in type IIa diamond subjected to fast neutron fluence. It is concluded that the rate of production of defects during transmutation reaction is slower when thermal neutrons are used. The thermal conductivity of epilayer of diamond subjected to high thermal and fast neutron fluence is associated with the covalent carbon network in the composite structure consisting of disordered carbon and sp{sup 2} bonded nanocrystalline regions.

  2. Fabrication of adherent porous diamond films on sintered WC-13 wt.%Co

    E-Print Network [OSTI]

    Bristol, University of

    biocompatibility, make it a very attractive material for a wide spectrum of applications in the fields of cutting tools, optical and electronic devices, etc. [1, 2]. Porous diamond (PD) films have received much recent substrates that had themselves been pre- coated with a thin WC-Co interlayer [13, 14]. Successful diamond

  3. Standards Panel: 1. Stephen Diamond, General Manager, Industry Standards Office and Global Standards Officer, EMC

    E-Print Network [OSTI]

    Standards Panel: 1. Stephen Diamond, General Manager, Industry Standards Office and Global was President of the IEEE Computer Society. Steve is General Manager of the Industry Standards Office at EMC Standards Officer, EMC Corporation, Office of the CTO Steve Diamond has 30 years of management, marketing

  4. Wind Power

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

    Wind Power Bioenergy Power Systems Wind Power Wind Power Main Page Outreach Programs Image Gallery FAQs Links Software Hydro Power INL Home Wind Power Introduction The Wind Power...

  5. A connection between plasma conditions near black hole event horizons and outflow properties

    E-Print Network [OSTI]

    Koljonen, K I I; Ontiveros, J A Fernández; Markoff, S; Russell, T D; Miller-Jones, J C A; van der Horst, A J; Bernardini, F; Casella, P; Curran, P A; Gandhi, P; Soria, R

    2015-01-01

    Accreting black holes are responsible for producing the fastest, most powerful outflows of matter in the Universe. The formation process of powerful jets close to black holes is poorly understood, and the conditions leading to jet formation are currently hotly debated. In this paper, we report an unambiguous empirical correlation between the properties of the plasma close to the black hole and the particle acceleration properties within jets launched from the central regions of accreting stellar-mass and supermassive black holes. In these sources the emission of the plasma near the black hole is characterized by a power law at X-ray energies during times when the jets are produced. We find that the photon index of this power law, which gives information on the underlying particle distribution, correlates with the characteristic break frequency in the jet spectrum, which is dependent on magnetohydrodynamical processes in the outflow. The observed range in break frequencies varies by five orders of magnitude, i...

  6. Gravitational wave production by rotating primordial black holes

    E-Print Network [OSTI]

    Dong, Ruifeng; Stojkovic, Dejan

    2015-01-01

    In this paper we analyze in detail a rarely discussed question of gravity waves production from evaporating black holes. Evaporating black holes emit gravitons which are at classical level registered as gravity waves. We use the latest constraints on the primordial black hole abundance, and calculate the power emitted in gravitons at the time of their evaporation. We then solve the coupled system of equations that gives us the evolution of the frequency and amplitude of gravity waves during the expansion of the universe. The spectrum of gravitational waves that can be detected today depends on multiple factors: fraction of the total energy density which was occupied by black holes, the epoch in which the black holes are formed, and quantities like mass and angular momentum of evaporating black holes. We conclude that very small primordial black holes which evaporate before the nucleosynthesis emit gravitons whose spectral energy fraction today can be as large as $10^{-5}$. On the other hand, primordial black ...

  7. Vacuum encapsulated hermetically sealed diamond amplified cathode capsule and method for making same

    DOE Patents [OSTI]

    Rao, Triveni; Walsh, John; Gangone, Elizabeth

    2014-12-30

    A vacuum encapsulated, hermetically sealed cathode capsule for generating an electron beam of secondary electrons, which generally includes a cathode element having a primary emission surface adapted to emit primary electrons, an annular insulating spacer, a diamond window element comprising a diamond material and having a secondary emission surface adapted to emit secondary electrons in response to primary electrons impinging on the diamond window element, a first cold-weld ring disposed between the cathode element and the annular insulating spacer and a second cold-weld ring disposed between the annular insulating spacer and the diamond window element. The cathode capsule is formed by a vacuum cold-weld process such that the first cold-weld ring forms a hermetical seal between the cathode element and the annular insulating spacer and the second cold-weld ring forms a hermetical seal between the annular spacer and the diamond window element whereby a vacuum encapsulated chamber is formed within the capsule.

  8. Vacuum encapsulated, high temperature diamond amplified cathode capsule and method for making same

    DOE Patents [OSTI]

    Rao, Triveni; Walsh, John; Gangone, Elizabeth

    2015-12-29

    A vacuum encapsulated, hermetically sealed cathode capsule for generating an electron beam of secondary electrons, which generally includes a cathode element having a primary emission surface adapted to emit primary electrons, an annular insulating spacer, a diamond window element comprising a diamond material and having a secondary emission surface adapted to emit secondary electrons in response to primary electrons impinging on the diamond window element, a first high-temperature solder weld disposed between the diamond window element and the annular insulating spacer and a second high-temperature solder weld disposed between the annular insulating spacer and the cathode element. The cathode capsule is formed by a high temperature weld process under vacuum such that the first solder weld forms a hermetical seal between the diamond window element and the annular insulating spacer and the second solder weld forms a hermetical seal between the annular spacer and the cathode element whereby a vacuum encapsulated chamber is formed within the capsule.

  9. Engineering shallow spins in diamond with nitrogen delta-doping

    SciTech Connect (OSTI)

    Ohno, Kenichi; Joseph Heremans, F.; Bassett, Lee C.; Myers, Bryan A.; Toyli, David M.; Bleszynski Jayich, Ania C.; Palmstrom, Christopher J.; Awschalom, David D.

    2012-08-20

    We demonstrate nanometer-precision depth control of nitrogen-vacancy (NV) center creation near the surface of synthetic diamond using an in situ nitrogen delta-doping technique during plasma-enhanced chemical vapor deposition. Despite their proximity to the surface, doped NV centers with depths (d) ranging from 5 to 100 nm display long spin coherence times, T{sub 2} > 100 {mu}s at d = 5 nm and T{sub 2} > 600 {mu}s at d {>=} 50 nm. The consistently long spin coherence observed in such shallow NV centers enables applications such as atomic-scale external spin sensing and hybrid quantum architectures.

  10. Alignment of the diamond nitrogen vacancy center by strain engineering

    SciTech Connect (OSTI)

    Karin, Todd [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Dunham, Scott [Department of Electrical Engineering, University of Washington, Seattle, Washington 98195 (United States); Fu, Kai-Mei [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Department of Electrical Engineering, University of Washington, Seattle, Washington 98195 (United States)

    2014-08-04

    The nitrogen vacancy (NV) center in diamond is a sensitive probe of magnetic field and a promising qubit candidate for quantum information processing. The performance of many NV-based devices improves by aligning the NV(s) parallel to a single crystallographic direction. Using ab initio theoretical techniques, we show that NV orientation can be controlled by high-temperature annealing in the presence of strain under currently accessible experimental conditions. We find that (89?±?7)% of NVs align along the [111] crystallographic direction under 2% compressive biaxial strain (perpendicular to [111]) and an annealing temperature of 970?°C.

  11. Charging characteritiscs of ultrananocrystalline diamond in RF MEMS capacitive switches.

    SciTech Connect (OSTI)

    Sumant, A. V.; Goldsmith, C.; Auciello, O.; Carlisle, J.; Zheng, H.; Hwang, J. C. M.; Palego, C.; Wang, W.; Carpick, R.; Adiga, V.; Datta, A.; Gudeman, C.; O'Brien, S.; Sampath, S.

    2010-05-01

    Modifications to a standard capacitive MEMS switch process have been made to allow the incorporation of ultra-nano-crystalline diamond as the switch dielectric. The impact on electromechanical performance is minimal. However, these devices exhibit uniquely different charging characteristics, with charging and discharging time constants 5-6 orders of magnitude quicker than conventional materials. This operation opens the possibility of devices which have no adverse effects of dielectric charging and can be operated near-continuously in the actuated state without significant degradation in reliability.

  12. Method and apparatus for making diamond-like carbon films

    DOE Patents [OSTI]

    Pern, Fu-Jann (Golden, CO); Touryan, Kenell J. (Indian Hills, CO); Panosyan, Zhozef Retevos (Yerevan, AM); Gippius, Aleksey Alekseyevich (Moscow, RU)

    2008-12-02

    Ion-assisted plasma enhanced deposition of diamond-like carbon (DLC) films on the surface of photovoltaic solar cells is accomplished with a method and apparatus for controlling ion energy. The quality of DLC layers is fine-tuned by a properly biased system of special electrodes and by exact control of the feed gas mixture compositions. Uniform (with degree of non-uniformity of optical parameters less than 5%) large area (more than 110 cm.sup.2) DLC films with optical parameters varied within the given range and with stability against harmful effects of the environment are achieved.

  13. Blue Diamond, Nevada: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin:Pontiac Biomass Facility JumpIICalifornia: EnergyC LtdDiamond,

  14. Sandia Energy - Diamond Plates Create Nanostructures through Pressure,

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumniProjectsCyberNot Chemistry Diamond Plates Create

  15. JOURNAL OF MATERIALS SCIENCE LETTERS, 14 (1995) 1448-1450 A technique for the manufacture of long hollow diamond fibres by

    E-Print Network [OSTI]

    Bristol, University of

    1995-01-01

    substrates, which has limited CVD diamond applications to optical or wear resistant coatings and cutting tools [4]. Recently, continuous CVD diamond fibres have been produced by coating CVD diamond onto wires diamond coated shape obtained depends on the dimensions of the coil (Fig. 2a). A continuous solid fibre

  16. Power Plant Power Plant

    E-Print Network [OSTI]

    Stillwater Power Plant Wabuska Power Plant Casa Diablo Power Plant Glass Mountain Geothermal Area Lassen Geothermal Area Coso Hot Springs Power Plants Lake City Geothermal Area Thermo Geothermal Area Lakeview Geothermal Area Raft River Geothermal Area Cove Fort Power Plant Roosevelt Power Plant Borax Lake

  17. Nanofabrication of sharp diamond tips by e-beam lithography and inductively coupled plasma reactive ion etching.

    SciTech Connect (OSTI)

    Moldovan, N.; Divan, R.; Zeng, H.; Carlisle, J. A.; Advanced Diamond Tech.

    2009-12-07

    Ultrasharp diamond tips make excellent atomic force microscopy probes, field emitters, and abrasive articles due to diamond's outstanding physical properties, i.e., hardness, low friction coefficient, low work function, and toughness. Sharp diamond tips are currently fabricated as individual tips or arrays by three principal methods: (1) focused ion beam milling and gluing onto a cantilever of individual diamond tips, (2) coating silicon tips with diamond films, or (3) molding diamond into grooves etched in a sacrificial substrate, bonding the sacrificial substrate to another substrate or electrodepositing of a handling chip, followed by dissolution of the sacrificial substrate. The first method is tedious and serial in nature but does produce very sharp tips, the second method results in tips whose radius is limited by the thickness of the diamond coating, while the third method involves a costly bonding and release process and difficulties in thoroughly filling the high aspect ratio apex of molding grooves with diamond at the nanoscale. To overcome the difficulties with these existing methods, this article reports on the feasibility of the fabrication of sharp diamond tips by direct etching of ultrananocrystalline diamond (UNCD{reg_sign}) as a starting and structural material. The UNCD is reactive ion etched using a cap-precursor-mask scheme. An optimized etching recipe demonstrates the formation of ultrasharp diamond tips ({approx} 10 nm tip radius) with etch rates of 650 nm/min.

  18. Ultrananocrystalline and nanocrystalline diamond thin films for NEMS/MEMS applications.

    SciTech Connect (OSTI)

    Sumant, A. V.; Auciello, O.; Carpick, R. W.; Srinivasan, S.; Butler, J. E. (Center for Nanoscale Materials); ( MSD); ( PSC-USR)

    2010-04-01

    There has been a tireless quest by the designers of micro- and nanoelectro mechanical systems (MEMS/NEMS) to find a suitable material alternative to conventional silicon. This is needed to develop robust, reliable, and long-endurance MEMS/NEMS with capabilities for working under demanding conditions, including harsh environments, high stresses, or with contacting and sliding surfaces. Diamond is one of the most promising candidates for this because of its superior physical, chemical, and tribomechanical properties. Ultrananocrystalline diamond (UNCD) and nanocrystalline diamond (NCD) thin films, the two most studied forms of diamond films in the last decade, have distinct growth processes and nanostructures but complementary properties. This article reviews the fundamental and applied science performed to understand key aspects of UNCD and NCD films, including the nucleation and growth, tribomechanical properties, electronic properties, and applied studies on integration with piezoelectric materials and CMOS technology. Several emerging diamond-based MEMS/NEMS applications, including high-frequency resonators, radio frequency MEMS and photonic switches, and the first commercial diamond MEMS product - monolithic diamond atomic force microscopy probes - are discussed.

  19. The renaissance of black phosphorus

    E-Print Network [OSTI]

    Ling, Xi

    One hundred years after its first successful synthesis in the bulk form in 1914, black phosphorus (black P) was recently rediscovered from the perspective of a 2D layered material, attracting tremendous interest from ...

  20. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Giuseppe Lodato; Priyamvada Natarajan

    2007-02-13

    In this paper we derive the mass function of seed black holes that result from the central mass concentrated via disc accretion in collapsed haloes at redshift $z\\approx 15$. Using standard arguments including stability, we show that these pre-galactic discs can assemble a significant mass concentration in the inner regions, providing fuel for the formation and initial growth of super-massive black holes. Assuming that these mass concentrations do result in central seed black holes, we determine the mass distribution of these seeds as a function of key halo properties. The seed mass distribution determined here turns out to be asymmetric and skewed to higher masses. Starting with these initial seeds, building up to $10^9$ solar masses by $z = 6$ to power the bright quasars is not a problem in the standard LCDM cosmogony. These seed black holes in gas rich environments are likely to grow into the supermassive black holes at later times via mergers and accretion. Gas accretion onto these seeds at high redshift will produce miniquasars that likely play an important role in the reionization of the Universe. Some of these seed black holes on the other hand could be wandering in galaxy haloes as a consequence of frequent mergers, powering the off-nuclear ultra-luminous X-ray sources detected in nearby galaxies.

  1. Diamondization of Graphene and Graphene-BN Bilayers: Chemical Functionalization and Electronic Structure Engineering

    E-Print Network [OSTI]

    Yuan, Long; Yang, Jinlong; Hou, Jian Guo

    2011-01-01

    In this article, based on first-principles calculations, we systematically study functionalization induced diamonization of graphene bilayer and graphene-BN hybrid bilayer. With single-side functionalization, the diamondized structures are magnetic semiconductor. Interestingly, if both sides of the bilayer are functionalized, diamondization becomes spontaneous without a barrier. On the other hand, when the bottom layer of the bilayer graphene is replaced by a single hexagonal BN layer, the diamondized structure becomes nonmagnetic metal. The tunable electronic and magnetic properties pave new avenues to construct graphene-based electronics and spintronics devices.

  2. Adhesion of diamond coatings synthesized by oxygen-acetylene flame CVD on tungsten carbide

    SciTech Connect (OSTI)

    Marinkovic, S.; Stankovic, S.; Dekanski, A.

    1995-12-31

    The results of a study concerned with chemical vapor deposition of diamond on tungsten carbide cutting tools using an oxygen-acetylene flame in a normal ambient environment are presented. Effects of preparation conditions on the adhesion of the coating have been investigated, including different surface treatment, different position of the flame with respect to the coated surface, effect of an intermediate poorly crystalline diamond layer, etc. In particular, effect of polishing and ultrasonic lapping with diamond powder was compared with that of a corresponding treatment with SiC powder.

  3. Black Holes And Their Entropy 

    E-Print Network [OSTI]

    Mei, Jianwei

    2010-10-12

    . . . . . . . . . 21 1. Solutions in Four Dimensions . . . . . . . . . . . . . . 22 2. Solutions in Higher Dimensions . . . . . . . . . . . . . 27 C. Black Hole Solutions in Supergravity Theories . . . . . . . 30 D. Plebanski-Demianski Type Solutions in d = 5... is to discuss the construction of new black hole solutions and the calculation of the black hole entropy. In Chapter II, we shall re- port some new black hole solutions that we have found during the past few years [21, 22, 23] and we will discuss some...

  4. Measurements and Studies of Secondary Electron Emission of Diamond Amplified Photocathode

    SciTech Connect (OSTI)

    Wu,Q.

    2008-10-01

    The Diamond Amplified Photocathode (DAP) is a novel approach to generating electrons. By following the primary electron beam, which is generated by traditional electron sources, with an amplifier, the electron beam available to the eventual application is increased by 1 to 2 orders of magnitude in current. Diamond has a very wide band gap of 5.47eV which allows for a good negative electron affinity with simple hydrogenation, diamond can hold more than 2000MV/m field before breakdown. Diamond also provides the best rigidity among all materials. These two characters offer the capability of applying high voltage across very thin diamond film to achieve high SEY and desired emission phase. The diamond amplifier also is capable of handling a large heat load by conduction and sub-nanosecond pulse input. The preparation of the diamond amplifier includes thinning and polishing, cleaning with acid etching, metallization, and hydrogenation. The best mechanical polishing available can provide high purity single crystal diamond films with no less than 100 {micro}m thickness and <15 nm Ra surface roughness. The ideal thickness for 700MHz beam is {approx}30 {micro}m, which requires further thinning with RIE or laser ablation. RIE can achieve atomic layer removal precision and roughness eventually, but the time consumption for this procedure is very significant. Laser ablation proved that with <266nm ps laser beam, the ablation process on the diamond can easily achieve removing a few microns per hour from the surface and <100nm roughness. For amplifier application, laser ablation is an adequate and efficient process to make ultra thin diamond wafers following mechanical polishing. Hydrogenation will terminate the diamond surface with monolayer of hydrogen, and form NEA so that secondary electrons in the conduction band can escape into the vacuum. The method is using hydrogen cracker to strike hydrogen atoms onto the bare diamond surface to form H-C bonds. Two independent experiments were carried out to determine the transport of the electrons within the diamond and their emission at the surface. In transmission mode measurements, the diamond amplifier was coated with metal on both sides, so results simply depend only on the electron transport within the diamond. The SEY for this mode provides one secondary electron per 20eV energy, which gives the gain of more than 200 for 4.7keV (effective energy) primary electrons under 2MV/m. Laser detrapping can help the signal maintain the gain with lops pulse and duty cycle of 1.67 x 10{sup -7}. In emission mode measurements, in which the diamond is prepared as in the actual application, the SEY is {approx}20 for 700eV (effective energy) primary electrons under 1.21MV/m. The electric field applied and the primary electron energy is limited by the experiment setup, but the results show good trend toward large gain under high field. Thermal emittance of the diamond secondary emission is critical for the beam application. A careful design is setup to measure with very fine precision and accuracy of 0.01eV.

  5. Numerical Simulations Reveal the Origin of QPOs in Black Hole Candidates

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    We present results of various types of numerical simulations of black hole accretion disks and find that those flows which are relatively non-dissipative and which contain accretion shocks are the best candidates so far. The power density spectra (PDS) reveal the aspects which are similar to what are observed in black hole candidates.

  6. Black Holes at Accelerators

    E-Print Network [OSTI]

    Bryan Webber

    2006-04-06

    In theories with large extra dimensions and TeV-scale gravity, black holes are copiously produced in particle collisions at energies well above the Planck scale. I briefly review some recent work on the phenomenology of this process, with emphasis on theoretical uncertainties and possible strategies for measuring the number of extra dimensions.

  7. Gasification of black liquor

    DOE Patents [OSTI]

    Kohl, Arthur L. (Woodland Hills, CA)

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

  8. Gasification of black liquor

    DOE Patents [OSTI]

    Kohl, A.L.

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediately above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone. 2 figs.

  9. Statistical Mechanics of Black Holes

    E-Print Network [OSTI]

    B. Harms; Y. Leblanc

    1992-05-11

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black hole decay and of quantum coherence are also addressed.

  10. Study of narrowband single photon emitters in polycrystalline diamond films

    SciTech Connect (OSTI)

    Sandstrom, Russell G.; Shimoni, Olga; Martin, Aiden A.; Aharonovich, Igor, E-mail: igor.aharonovich@uts.edu.au [School of Physics and Advanced Materials, University of Technology, Sydney, P.O. Box 123, Broadway, New South Wales 2007 (Australia)

    2014-11-03

    Quantum information processing and integrated nanophotonics require robust generation of single photon emitters on demand. In this work, we demonstrate that diamond films grown on a silicon substrate by microwave plasma chemical vapor deposition can host bright, narrowband single photon emitters in the visible—near infra-red spectral range. The emitters possess fast lifetime (?several ns), absolute photostability, and exhibit full polarization at excitation and emission. Pulsed and continuous laser excitations confirm their quantum behaviour at room temperature, while low temperature spectroscopy is performed to investigate inhomogeneous broadening. Our results advance the knowledge of solid state single photon sources and open pathways for their practical implementation in quantum communication and quantum information processing.

  11. Optically transparent, scratch-resistant, diamond-like carbon coatings

    DOE Patents [OSTI]

    He, Xiao-Ming; Lee, Deok-Hyung; Nastasi, Michael A.; Walter, Kevin C.; Tuszewski, Michel G.

    2003-06-03

    A plasma-based method for the deposition of diamond-like carbon (DLC) coatings is described. The process uses a radio-frequency inductively coupled discharge to generate a plasma at relatively low gas pressures. The deposition process is environmentally friendly and scaleable to large areas, and components that have geometrically complicated surfaces can be processed. The method has been used to deposit adherent 100-400 nm thick DLC coatings on metals, glass, and polymers. These coatings are between three and four times harder than steel and are therefore scratch resistant, and transparent to visible light. Boron and silicon doping of the DLC coatings have produced coatings having improved optical properties and lower coating stress levels, but with slightly lower hardness.

  12. Persistence of Single Spin Coherence above 600K in Diamond

    E-Print Network [OSTI]

    Toyli, D M; Alkauskas, A; Buckley, B B; Van de Walle, C G; Awschalom, D D

    2012-01-01

    We study the spin and orbital dynamics of single nitrogen vacancy (NV) centers in diamond between room temperature and 700 K. We find that the ability to optically address and coherently control single spins above room temperature is limited by nonradiative processes that quench the NV center's fluorescence-based spin readout between 550 K and 700 K. Combined with electronic structure calculations, our measurements indicate that the energy difference between the 3E and 1A1 electronic states is approximately 0.8 eV. We also find that the inhomogeneous spin lifetime (T2*) is independent of temperature up to at least 625 K, suggesting that single NV centers could be applied as nanoscale thermometers over a broad temperature range.

  13. Polycrystalline diamond MEMS resonator technology for sensor applications.

    SciTech Connect (OSTI)

    Sullivan, John P.; Aslam, Dean (Michigan State University, East Lansing, MI); Sepulveda-Alancastro, Nelson (Michigan State University, East Lansing, MI)

    2005-07-01

    Due to material limitations of poly-Si resonators, polycrystalline diamond (poly-C) has been explored as a new MEMS resonator material. The poly-C resonators are designed, fabricated and tested using electrostatic (Michigan State University) and piezoelectric (Sandia National Laboratories) actuation methods, and the results are compared. For comparable resonator structures, although the resonance frequencies are similar, the measured Q values in the ranges of 1000-2000 and 10,000-15,000 are obtained for electrostatic and piezoelectric actuation methods, respectively. The difference in Q for the two methods is related to different pressures used during the measurement and not to the method of measurement. For the poly-C cantilever beam resonators, the highest value of their quality factor (Q) is reported for the first time (15,263).

  14. Sensitive Magnetic Control of Ensemble Nuclear Spin Hyperpolarisation in Diamond

    E-Print Network [OSTI]

    Wang, Hai-Jing; Avalos, Claudia E; Seltzer, Scott J; Budker, Dmitry; Pines, Alexander; Bajaj, Vikram S

    2012-01-01

    Dynamic nuclear polarisation, which transfers the spin polarisation of electrons to nuclei, is routinely applied to enhance the sensitivity of nuclear magnetic resonance; it is also critical in spintronics, particularly when spin hyperpolarisation can be produced and controlled optically or electrically. Here we show the complete polarisation of nuclei located near the optically-polarised nitrogen-vacancy (NV) centre in diamond. When approaching the ground-state level anti-crossing condition of the NV electron spins, 13C nuclei in the first-shell are polarised in a pattern that depends sensitively and sharply upon the magnetic field. Based on the anisotropy of the hyperfine coupling and of the optical polarisation mechanism, we predict and observe a complete reversal of the nuclear spin polarisation with a few-mT change in the magnetic field. The demonstrated sensitive magnetic control of nuclear polarisation at room temperature will be useful for sensitivity-enhanced NMR, nuclear-based spintronics, and quant...

  15. Examination of the Material Removal Rate in Lapping Polycrystalline Diamond Compacts 

    E-Print Network [OSTI]

    Sowers, Jason Michael

    2012-10-19

    This study examines the lapping machining process used during the manufacturing of polycrystalline diamond compacts (PDCs). More specifically, it is aimed at improving the productivity of the process by developing a better understanding...

  16. FURTHER NOTES ON THE NATURAL HISTORY AND ARTIFICIAL PROPAGATION OF THE DIAMOND-BACK TERRAPIN.

    E-Print Network [OSTI]

    on the artificial propagation of the diamond-back terrapin, Malaclemmys cenirata, at the United States Fisheries been directed since its beginning by several investigators. Originally Dr. R. E. Coker gave his

  17. The semi-empirical tight-binding model for carbon allotropes “between diamond and graphite”

    SciTech Connect (OSTI)

    Lytovchenko, V.; Kurchak, A.; Strikha, M.

    2014-06-28

    The new carbon allotropes “between diamond and graphite” have come under intensive examination during the last decade due to their numerous technical applications. The modification of energy gap in thin films of these allotropes was studied experimentally using optical methods. The proposed simple model of carbon clusters with variable lengths of chemical bonds allows us to imitate the transfer from diamond and diamond-like to graphite-like structures, as well as the corresponding modification of hybridization sp{sup 3}/sp{sup 2} for diamond-like and sp{sub z} for graphite-like phases. This enables us to estimate various allotropes parameters, like the gap E{sub g}, energies of valence E{sub v}, and conduction E{sub c} band edges, and the value of electronic affinity, i.e., optical work function X, which are all of practical importance. The obtained estimations correspond to the experimental data.

  18. Diamond Amplified Photocathode at BNL | U.S. DOE Office of Science...

    Office of Science (SC) Website

    The diamond amplified photocathode may improve the performance of laser-photocathode RF guns by providing a robust, high quantum-efficiency, low thermal-emittance cathode. In the...

  19. Electrochemically grafted polypyrrole changes photoluminescence of electronic states inside nanocrystalline diamond

    SciTech Connect (OSTI)

    Galá?, P. Malý, P.; ?ermák, J.; Kromka, A.; Rezek, B.

    2014-12-14

    Hybrid diamond-organic interfaces are considered attractive for diverse applications ranging from electronics and energy conversion to medicine. Here we use time-resolved and time-integrated photoluminescence spectroscopy in visible spectral range (380–700?nm) to study electronic processes in H-terminated nanocrystalline diamond films (NCD) with 150?nm thin, electrochemically deposited polypyrrole (PPy) layer. We observe changes in dynamics of NCD photoluminescence as well as in its time-integrated spectra after polymer deposition. The effect is reversible. We propose a model where the PPy layer on the NCD surface promotes spatial separation of photo-generated charge carriers both in non-diamond carbon phase and in bulk diamond. By comparing different NCD thicknesses we show that the effect goes as much as 200?nm deep inside the NCD film.

  20. Model of the competitive growth of amorphous carbon and diamond films I. J. Forda)

    E-Print Network [OSTI]

    Ford, Ian

    be deposited on a silicon wafer mounted on a rotating platform, which was exposed sequen- tially to fluxes carbon films could be deposited (for an increase in the car- bon flux) or diamond films were produced (by

  1. Evaluation of TexSIM for modeling traffic behavior at diamond interchanges 

    E-Print Network [OSTI]

    Meadors, Allison Christine Cherry

    1995-01-01

    Poor operation of diamond interchanges along a freeway corridor can decrease the mobility of the corridor and increase time and energy costs associated with delay at signalized interchanges. Computer simulation provides a safe and efficient means...

  2. Preparation of W-Ta thin-film thermocouple on diamond anvil cell...

    Office of Scientific and Technical Information (OSTI)

    Preparation of W-Ta thin-film thermocouple on diamond anvil cell for in-situ temperature measurement under high pressure Citation Details In-Document Search Title: Preparation of...

  3. Energy extraction from boosted black holes: Penrose process, jets, and the membrane at infinity

    E-Print Network [OSTI]

    Robert F. Penna

    2015-04-15

    Numerical simulations indicate that black holes carrying linear momentum and/or orbital momentum can power jets. The jets extract the kinetic energy stored in the black hole's motion. This could provide an important electromagnetic counterpart to gravitational wave searches. We develop the theory underlying these jets. In particular, we derive the analogues of the Penrose process and the Blandford-Znajek jet power prediction for boosted black holes. The jet power we find is $(v/2M)^2 \\Phi^2/(4\\pi)$, where $v$ is the hole's velocity, $M$ is its mass, and $\\Phi$ is the magnetic flux. We show that energy extraction from boosted black holes is conceptually similar to energy extraction from spinning black holes. However, we highlight two key technical differences: in the boosted case, jet power is no longer defined with respect to a Killing vector, and the relevant notion of black hole mass is observer dependent. We derive a new version of the membrane paradigm in which the membrane lives at infinity rather than the horizon and we show that this is useful for interpreting jets from boosted black holes. Our jet power prediction and the assumptions behind it can be tested with future numerical simulations.

  4. Nucleation of nanocrystalline diamond by fragmentation of fullerene precursors.

    SciTech Connect (OSTI)

    Gruen, D. M.

    1998-05-04

    Growth of diamond films from C{sub 60}/Ar microwave discharges results in a nanocrystalline microstructure with crystallite sizes in the range 3-10 nm. Heterogeneous nucleation rates of 10{sup 10} cm{sup {minus}2} sec are required to account for the results. The nucleation mechanism presented here fulfills this requirement and is based on the insertion of carbon dimer, C{sub 2}, molecules, produced by fragmentation of C{sub 60}, into the n-bonded dimer rows of the reconstructed (100) surface of diamond. Density functional theory is used to calculate the energetic of C{sub 2} insertion into carbon clusters that model the (100) surface. The reaction of singlet C{sub 2} with the double bond of the C{sub 9}H{sub 12} cluster leads to either carbene structures or a cyclobutynelike structure. At the HF/6-31G* level, the carbene product has a C{sub 2v} structure, while at the B3LYP/6-31G* levels of theory, it has a C{sub s} structure with the inserted C{sub 2} tilted. No barrier for insertion into the C=C double bond of the C{sub 9}H{sub 12} cluster was found at the HF/6-31G* and B3LYP/6-31G* levels of theory. Thus, calculations including correlation energy and geometry optimization indicate that insertion of C{sub 2} into a C=C double bond leads to a large energy lowering, {approximately}120 kcal/mol for a C{sub 9}H{sub 12} cluster, and there is no barrier for insertion.

  5. Identification of Astrophysical Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1998-03-19

    Black holes are by definition black, and therefore cannot be directly observed by using electromagnetic radiations. Convincing identification of black holes must necessarily depend on the identification of a very specially behaving matter and radiation which surround them. A major problem in this subject of black hole astrophysics is to quantify the behaviour of matter and radiation close to the horizon. In this review, the subject of black hole accretion and outflow is systematically developed. It is shown that both the stationary as well as the non-stationary properties of the observed spectra could be generally understood by these solutions. It is suggested that the solutions of radiative hydrodynamic equations may produce clear spectral signatures of black holes. Other circumstantial evidences of black holes, both in the galactic centers as well as in binary systems, are also presented.

  6. On the wave energy potential of Western Black Sea shelf

    E-Print Network [OSTI]

    Galabov, Vasko

    2013-01-01

    In the present study we evaluate the approaches to estimate the wave energy potential of the western Black Sea shelf with numerical models. For the purpose of our evaluation and due to the lack of long time series of measurements in the selected area of the Black Sea, we compare the modeled mean wave power flux output from the SWAN wave model with the only available long term measurements from the buoy of Gelendzhik for the period 1997-2003 (with gaps). The forcing meteorological data for the numerical wave models for the selected years is extracted from the ERA Interim reanalysis of ECMWF (European Centre for Medium range Forecasts). For the year 2003 we also compare the estimated wave power with the modeled by SWAN, using ALADIN regional atmospheric model winds. We try to identify the shortcomings and limitations of the numerical modeling approach to the evaluation of the wave energy potential in Black Sea.

  7. Influence of diamond turning and surface cleaning processes on the degradation of KDP crystal surfaces

    SciTech Connect (OSTI)

    Kozlowski, M.R.; Thomas, I.; Edwards, G.; Stanion, K.; Fuchs, B.

    1991-06-24

    One factor influencing the efficiency of KDP (potassium dihydrogen phosphate) frequency conversion arrays on the Nova laser system at LLNL has been environmental degradation, or fogging'', of the crystal surfaces. Decreases in array transmission by as much as 20% have been attributed to crystal fogging. The surfaces of the 27-cm square Nova array crystals are prepared by a wet diamond-turning process. The rate of surface fogging has been associated with several parameters of the diamond turning and subsequent cleaning processes. High humidity during diamond turning, storage, and use on the laser tends to accelerate the fogging. We suspect that some of the additives present in the diamond turning oil increase the fogging rate and have found a machining oil which minimizes this surface degradation. Efficient removal of the machining oils from the crystal surface also minimizes the fogging problem. Care must be taken to use cleaning solvents which do not cause additional surface degradation. The fogging rate is sensitive to the crystallographic orientation of the material as well as to surface roughness related to the diamond turning process. Accelerated fogging at diamond turning artifacts may increase crystal surface roughness causing increased beam modulation and scattering losses. 5 refs. 5 figs.

  8. Black Hole Scan

    E-Print Network [OSTI]

    Juan Crisostomo; Ricardo Troncoso; Jorge Zanelli

    2000-09-22

    Gravitation theories selected by requiring that they have a unique anti-de Sitter vacuum with a fixed cosmological constant are studied. For a given dimension d, the Lagrangians under consideration are labeled by an integer k=1,2,...,[(d-1)/2]. Black holes for each d and k are found and are used to rank these theories. A minimum possible size for a localized electrically charged source is predicted in the whole set of theories, except General Relativity. It is found that the thermodynamic behavior falls into two classes: If d-2k=1, these solutions resemble the three dimensional black hole, otherwise, their behavior is similar to the Schwarzschild-AdS_4 geometry.

  9. Black holes at accelerators.

    E-Print Network [OSTI]

    Webber, Bryan R

    be presented and the effects of some of the uncertainties can be investigated. 3.1. Hawking Spectrum With the above assumptions, the spectrum of particles emitted during black hole decay takes the form dN dE ? ?E2 (eE/TH ? 1) T n+6H (8) where as usual... the trapped surface area [6, 7]. T030 02 4 6 8 10 0 0.2 0.4 0.6 0.8 1 1.2 n=0 n=1 n=2 n=6 E rS ?ˆ (0 ) ab s/ pi r2 S Figure 4: Grey-body factors for scalar emission on the brane from a (4 + n)D black hole. 0 2 4 6 8 10 0 0.2 0.4 0.6 0.8 1 1.2 n=0 n=1 n=2 n=6 E...

  10. Black Pine Circle Project

    SciTech Connect (OSTI)

    Mytko, Christine

    2014-03-31

    A group of seventh graders from Black Pine Circle school in Berkeley had the opportunity to experience the Advanced Light Source (ALS) as "users" via a collaborative field trip and proposal project. The project culminated with a field trip to the ALS for all seventh graders, which included a visit to the ALS data visualization room, a diffraction demonstration, a beamline tour, and informative sessions about x-rays and tomography presented by ALS scientists.

  11. Black Pine Circle Project

    ScienceCinema (OSTI)

    Mytko, Christine

    2014-09-15

    A group of seventh graders from Black Pine Circle school in Berkeley had the opportunity to experience the Advanced Light Source (ALS) as "users" via a collaborative field trip and proposal project. The project culminated with a field trip to the ALS for all seventh graders, which included a visit to the ALS data visualization room, a diffraction demonstration, a beamline tour, and informative sessions about x-rays and tomography presented by ALS scientists.

  12. Black Hole Demographics

    E-Print Network [OSTI]

    Laura Ferrarese

    2002-03-04

    The purpose of this contribution is to review the current status of black hole demographics in light of recent advances in the study of high redshift QSOs (section 2), local AGNs (section 3) and local quiescent galaxies (section 4). I will then outline the prospects for future progress (section 5), and discuss what I believe will be the challenges for the years to come [ABRIDGED].

  13. The Black Hole Particle Accelerator as a Machine to make Baby Universes

    E-Print Network [OSTI]

    Hamilton, A J S

    2013-01-01

    General relativity predicts that the inner horizon of an astronomically realistic rotating black hole is subject to the mass inflation instability. The inflationary instability acts like a gravity-powered particle accelerator of extraordinary power, accelerating accreted streams of particles along the principal outgoing and ingoing null directions at the inner horizon to collision energies that would, if nothing intervened, typically exceed exponentially the Planck energy. The inflationary instability is fueled by ongoing accretion, and is occurring inevitably in essentially every black hole in our Universe. This extravagant machine, the Black Hole Particle Accelerator, has the hallmarks of a device to make baby universes. Since collisions are most numerous inside supermassive black holes, reproductive efficiency requires our Universe to make supermassive black holes efficiently, as is observed.

  14. The Black Hole Particle Accelerator as a Machine to make Baby Universes

    E-Print Network [OSTI]

    A. J. S. Hamilton

    2013-05-20

    General relativity predicts that the inner horizon of an astronomically realistic rotating black hole is subject to the mass inflation instability. The inflationary instability acts like a gravity-powered particle accelerator of extraordinary power, accelerating accreted streams of particles along the principal outgoing and ingoing null directions at the inner horizon to collision energies that would, if nothing intervened, typically exceed exponentially the Planck energy. The inflationary instability is fueled by ongoing accretion, and is occurring inevitably in essentially every black hole in our Universe. This extravagant machine, the Black Hole Particle Accelerator, has the hallmarks of a device to make baby universes. Since collisions are most numerous inside supermassive black holes, reproductive efficiency requires our Universe to make supermassive black holes efficiently, as is observed.

  15. Optical properties of black hole in the presence of plasma: shadow

    E-Print Network [OSTI]

    Farruh Atamurotov; Bobomurat Ahmedov; Ahmadjon Abdujabbarov

    2015-08-28

    We have studied photon motion around axially symmetric rotating Kerr black hole in the presence of plasma with radial power-law density. It is shown that in the presence of plasma the observed shape and size of shadow changes depending on i) plasma parameters, ii) black hole spin and iii) inclination angle between observer plane and axis of rotation of black hole. In order to extract pure effect of plasma influence on black hole image the particular case of the Schwarzschild black hole has also been investigated and it has been shown that i) the photon sphere around the spherical symmetric black hole is left unchanged under the plasma influence, ii) however the Schwarzschild black hole shadow size in plasma is reduced due to the refraction of the electromagnetic radiation in plasma environment of black hole. The study of the energy emission from the black hole in plasma shows that in the presence of plasma the maximal energy emission rate from the black hole decreases.

  16. Development of Designer Diamond Technology for High-Pressure-High Temperature Experiments in Support of the Stockpile Stewardship

    SciTech Connect (OSTI)

    Vohra, Yogesh, K.

    2003-08-27

    OAK B127 Development of Designer Diamond Technology for High-Pressure-High Temperature Experiments in Support of the Stockpile Stewardship

  17. Masses of Stellar Black Holes and Testing Theories of Gravitation

    E-Print Network [OSTI]

    K. A. Postnov; A. M. Cherepashchuk

    2004-01-22

    We analyze the mass distribution of stellar black holes derived from the light and radial velocity curves of optical stars in close binary systems using dynamical methods. The systematic errors inherent in this approach are discussed. These are associated primarily with uncertainties in models for the contribution from gaseous structures to the optical brightness of the systems under consideration. The mass distribution is nearly flat in the range 4-15M_sun. This is compared with the mass distribution for black holes in massive close binaries, which can be manifest as ultraluminous X-ray sources (L_x > 10^39 erg/s) observed in other galaxies. If the X-ray luminosities of these objects correspond to the Eddington limit, the black-hole mass distribution should be described by a power law, which is incompatible with the flat shape derived dynamically from observations of close binaries in our Galaxy. One possible explanation of this discrepancy is the rapid evaporation of stellar-mass black holes predicted in recent multi-dimensional models of gravity. This hypothesis can be verifed by measuring the stellar black-hole mass spectrum or finding isolated or binary black holes with masses below 3M_sun.

  18. Bright vigorous winds as signposts of supermassive black hole birth

    E-Print Network [OSTI]

    Fiacconi, Davide

    2015-01-01

    The formation of supermassive black holes is still an outstanding question. In the quasi-star scenario, black hole seeds experience an initial super-Eddington growth, that in less than a million years may leave a $10^4-10^5$ M$_{\\odot}$ black hole at the centre of a protogalaxy at $z \\sim 20-10$. Super-Eddington accretion, however, may be accompanied by vigorous mass loss that can limit the amount of mass that reaches the black hole. In this paper, we critically assess the impact of radiative driven winds, launched from the surface of the massive envelopes from which the black hole accretes. Solving the full wind equations coupled with the hydrostatic structure of the envelope, we find mass outflows with rates between a few tens and $10^4$ M$_{\\odot}$ yr$^{-1}$, mainly powered by advection luminosity within the outflow. We therefore confirm the claim by Dotan, Rossi & Shaviv (2011) that mass losses can severely affect the black hole seed early growth within a quasi-star. In particular, seeds with mass $>1...

  19. Physics of the Power Threshold Minimum for L-H M.A. Malkov

    E-Print Network [OSTI]

    Diamond, Patrick H.

    Diego Collaborators: P.H. Diamond 1, K. Miki 2, J.E. Rice 3 and G.R. Tynan 1 Supported by US DoE 1 / 19 #12;Outline 1 Motivation Pthr - the LH transition Power Threshold -Micro - Macro connection How does Conclusions 2 / 19 #12;Motivation and brief history of LH studies LH transition is a 33 (!) year-old story

  20. Probing Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher

    2008-08-25

    The equation of state (EoS) of dark energy $w$ remains elusive despite enormous experimental efforts to pin down its value and its time variation. Yet it is the single most important handle we have in our understanding of one of the most mysterious puzzle in nature, dark energy. This letter proposes a new method for measuring the EoS of dark energy by using the gravitational waves (GW) of black hole binaries. The method described here offers an alternative to the standard way of large scale surveys. It is well known that the mass of a black hole changes due to the accretion of dark energy but at an extremely slow rate. However, a binary of supermassive black holes (SBH) radiates gravitational waves with a power proportional to the masses of these accreting stars and thereby carries information on dark energy. These waves can propagate through the vastness of structure in the universe unimpeded. The orbital changes of the binary, induced by the energy loss from gravitational radiation, receive a large contribution from dark energy accretion. This contribution is directly proportional to $(1+w)$ and is dominant for SBH binaries with separation $R \\ge 1000$ parsec, thereby accelerating the merging process for $w > -1$ or ripping the stars apart for phantom dark energy with $w < -1$. Such orbital changes, therefore $w$, can be detected with LIGO and LISA near merging time, or with X-ray and radio measurements of Chandra and VLBA experiments.

  1. Black holes in general relativity

    E-Print Network [OSTI]

    Visser, Matt

    2009-01-01

    What is going on (as of August 2008) at the interface between theoretical general relativity, string-inspired models, and observational astrophysics? Quite a lot. In this mini-survey I will make a personal choice and focus on four specific questions: Do black holes "exist"? (For selected values of the word "exist".) Is black hole formation and evaporation unitary? Can one mimic a black hole to arbitrary accuracy? Can one detect the presence of a horizon using local physics?

  2. Response of diamond detector sandwich to 14 MeV neutrons

    E-Print Network [OSTI]

    M. Osipenko; M. Ripani; G. Ricco; B. Caiffi; F. Pompili; M. Pillon; G. Verona-Rinati; R. Cardarelli

    2015-10-27

    In this paper we present the measurement of the response of 50 $\\mu$m thin diamond detectors to 14 MeV neutrons. Such neutrons are produced in fusion reactors and are of particular interest for ITER neutron diagnostics. Among semiconductor detectors diamond has properties most appropriate for harsh radiation and temperature conditions of a fusion reactor. However, 300-500 $\\mu$m thick diamond detectors suffer significant radiation damage already at neutron fluences of the order of $10^{14}$ n/cm$^2$. It is expected that a 50 $\\mu$m thick diamond will withstand a fluence of $>10^{16}$ n/cm$^2$. We tested two 50 $\\mu$m thick single crystal CVD diamonds, stacked to form a "sandwich" detector for coincidence measurements. The detector measured the conversion of 14 MeV neutrons, impinging on one diamond, into $\\alpha$ particles which were detected in the second diamond in coincidence with nuclear recoil. For $^{12}C(n,\\alpha)^{9}Be$ reaction the total energy deposited in the detector gives access to the initial neutron energy value. The measured 14 MeV neutron detection sensitivity through this reaction by a detector of effective area 3$\\times$3 mm$^2$ was $5\\times 10^{-7}$ counts cm$^2$/n. This value is in good agreement with Geant4 simulations. The intrinsic energy resolution of the detector was found to be 240 keV FWHM which adds only 10 % to ITER's 14 MeV neutron energy spread.

  3. Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices

    SciTech Connect (OSTI)

    Auciello, O.; Krauss, A. R.; Gruen, D. M.; Jayatissa, A.; Sumant, A.; Tucek, J.; Mancini, D.; Molodvan, N.; Erdemir, A.; Ersoy, D.; Gardos, M. N.; Busman, H. G.; Meyer, E. M.

    2000-08-24

    MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties, and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors. However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophyllic surfaces, even these simple devices have limited dynamic range. Future MEMS applications that involve significant rolling or sliding contact will require the use of new materials with significantly improved mechanical and tribological properties, and the ability to perform well in harsh environments. Diamond is a superhard material of high mechanical strength, exceptional chemical inertness, and outstanding thermal stability. The brittle fracture strength is 23 times that of Si, and the projected wear life of diamond MEMS moving mechanical assemblies (MEMS-MMAs) is 10,000 times greater than that of Si MMAs. However, as the hardest known material, diamond is notoriously difficult to fabricate. Conventional CVD thin film deposition methods offer an approach to the fabrication of ultra-small diamond structures, but the films have large grain size, high internal stress, poor intergranular adhesion, and very rough surfaces, and are consequently ill-suited for MEMS-MMA applications. A thin film deposition process has been developed that produces phase-pure nanocrystalline diamond with morphological and mechanical properties that are ideally suited for MEMS applications in general, and MMA use in particular. The authors have developed lithographic techniques for the fabrication of diamond microstructure including cantilevers and multi-level devices, acting as precursors to micro-bearings and gears, making nanocrystalline diamond a promising material for the development of high performance MEMS devices.

  4. Quantum Mechanics and Black Holes

    E-Print Network [OSTI]

    Jose N. Pecina-Cruz

    2005-11-27

    This paper discusses the existence of black holes from the foundations of quantum mechanics. It is found that quantum mechanics rule out a possible gravitational collapse.

  5. Why Blue-Collar Blacks Help Less

    E-Print Network [OSTI]

    Smith, Sandra Susan; Young, Kara Alexis

    2013-01-01

    Exclude Black Men from Blue-Collar Jobs. Berkeley, CA:How Black and Latino Blue Collar Workers Make Decisionsof Sample Respondents Blue-Collar Latinos Blue-Collar Black

  6. Dermoscopy of black-spot poison ivy

    E-Print Network [OSTI]

    Rader, Ryan K; Mu, Ruipu; Shi, Honglan; Stoecker, William V; Hinton, Kristen A

    2012-01-01

    CT, Bean AS. Black-spot poison ivy: A rare phenomenon. J AmJG, Lucky AW. Black spot poison ivy: A report of 5 cases andis unique for black-spot poison ivy. The UFLC-MS/MS urushiol

  7. Green, Black, Lean Six Sigma and Master Black Belt Certifications

    E-Print Network [OSTI]

    Grissino-Mayer, Henri D.

    Green, Black, Lean Six Sigma and Master Black Belt Certifications Green BeLt CertifiCation Candidates may choose from three Green Belts offered: 1) Lean (one week of coursework) 2) Lean Six Sigma (two weeks of coursework) 3) Six Sigma (two weeks of coursework) Green Belt certification is a two

  8. Thermal BEC black holes

    E-Print Network [OSTI]

    Roberto Casadio; Andrea Giugno; Octavian Micu; Alessio Orlandi

    2015-11-04

    We review some features of BEC models of black holes obtained by means of the HWF formalism. We consider the KG equation for a toy graviton field coupled to a static matter current in spherical symmetry. The classical field reproduces the Newtonian potential generated by the matter source, while the corresponding quantum state is given by a coherent superposition of scalar modes with continuous occupation number. An attractive self-interaction is needed for bound states to form, so that (approximately) one mode is allowed, and the system of N bosons can be self-confined in a volume of the size of the Schwarzschild radius. The HWF is then used to show that the radius of such a system corresponds to a proper horizon. The uncertainty in the size of the horizon is related to the typical energy of Hawking modes: it decreases with the increasing of the black hole mass (larger number of gravitons), in agreement with semiclassical calculations and different from a single very massive particle. The spectrum contains a discrete ground state of energy $m$ (the bosons forming the black hole), and a continuous spectrum with energy $\\omega > m$ (representing the Hawking radiation and modelled with a Planckian distribution at the expected Hawking temperature). The $N$-particle state can be collectively described by a single-particle wave-function given by a superposition of a total ground state with energy $M = N m$ and a Planckian distribution for $E > M$ at the same Hawking temperature. The partition function is then found to yield the usual area law for the entropy, with a logarithmic correction related with the Hawking component. The backreaction of modes with $\\omega > m$ is also shown to reduce the Hawking flux and the evaporation properly stops for vanishing mass.

  9. High-Power Microwave Switch Employing Electron Beam Triggering

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2012-09-19

    A high-power active microwave pulse compressor is described that modulates the quality factor Q of the energy storage cavity by a new means involving mode conversion controlled by a triggered electron-beam discharge through a switch cavity. The electron beam is emitted from a diamond-coated molybdenum cathode. This report describes the principle of operation, the design of the switch, the configuration used for the test, and the experimental results. The pulse compressor produced output pulses with 140 - Ã?Â?165 MW peak power, power gain of 16 - 20, and pulse duration of 16 - 20 ns at a frequency of 11.43 GHz.

  10. Holographic Black Hole Chemistry

    E-Print Network [OSTI]

    Andreas Karch; Brandon Robinson

    2015-11-02

    Thermodynamic quantities associated with black holes in Anti-de Sitter space obey an interesting identity when the cosmological constant is included as one of the dynamical variables, the generalized Smarr relation. We show that this relation can easily be understood from the point of view of the dual holographic field theory. It amounts to the simple statement that the extensive thermodynamic quantities of a large $N$ gauge theory only depend on the number of colors, $N$, via an overall factor of $N^2$.

  11. The Nanoscience Beamline (I06) at Diamond Light Source

    SciTech Connect (OSTI)

    Dhesi, S. S.; Cavill, S. A.; Potenza, A.; Marchetto, H.; Mott, R. A.; Steadman, P.; Peach, A.; Shepherd, E. L.; Ren, X.; Wagner, U. H.; Reininger, R.

    2010-06-23

    The Nanoscience beamline (I06) is one of seven Diamond Phase-I beamlines which has been operational since January 2007 delivering polarised soft x-rays, for a PhotoEmission Electron Microscope (PEEM) and branchline, in the energy range 80-2100 eV. The beamline is based on a collimated plane grating monochromator with sagittal focusing elements, utilising two APPLE II helical undulator sources, and has been designed for high flux density at the PEEM sample position. A {approx}5 {mu}m ({sigma}) diameter beam is focussed onto the sample in the PEEM allowing a range of experiments using x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD) and x-ray magnetic linear dichroism (XMLD) as contrast mechanisms. The beamline is also equipped with a branchline housing a 6T superconducting magnet for XMCD and XMLD experiments. The magnet is designed to move on and off the branchline which allows a diverse range of experiments.

  12. Diamond detector for high rate monitors of fast neutrons beams

    SciTech Connect (OSTI)

    Giacomelli, L.; Rebai, M.; Cippo, E. Perelli; Tardocchi, M.; Fazzi, A.; Andreani, C.; Pietropaolo, A.; Frost, C. D.; Rhodes, N.; Schooneveld, E.; Gorini, G.

    2012-06-19

    A fast neutron detection system suitable for high rate measurements is presented. The detector is based on a commercial high purity single crystal diamond (SDD) coupled to a fast digital data acquisition system. The detector was tested at the ISIS pulsed spallation neutron source. The SDD event signal was digitized at 1 GHz to reconstruct the deposited energy (pulse amplitude) and neutron arrival time; the event time of flight (ToF) was obtained relative to the recorded proton beam signal t{sub 0}. Fast acquisition is needed since the peak count rate is very high ({approx}800 kHz) due to the pulsed structure of the neutron beam. Measurements at ISIS indicate that three characteristics regions exist in the biparametric spectrum: i) background gamma events of low pulse amplitudes; ii) low pulse amplitude neutron events in the energy range E{sub dep}= 1.5-7 MeV ascribed to neutron elastic scattering on {sup 12}C; iii) large pulse amplitude neutron events with E{sub n} < 7 MeV ascribed to {sup 12}C(n,{alpha}){sup 9}Be and 12C(n,n')3{alpha}.

  13. Modeling electron emission and surface effects from diamond cathodes

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

    Dimitrov, D. A.; Smithe, D.; Cary, J. R.; Ben-Zvi, I.; Rao, T.; Smedley, J.; Wang, E.

    2015-02-05

    We developed modeling capabilities, within the Vorpal particle-in-cell code, for three-dimensional (3D) simulations of surface effects and electron emission from semiconductor photocathodes. They include calculation of emission probabilities using general, piece-wise continuous, space-time dependent surface potentials, effective mass and band bending field effects. We applied these models, in combination with previously implemented capabilities for modeling charge generation and transport in diamond, to investigate the emission dependence on applied electric field in the range from approximately 2 MV/m to 17 MV/m along the [100] direction. The simulation results were compared to experimental data. For the considered parameter regime, conservation of transversemore »electron momentum (in the plane of the emission surface) allows direct emission from only two (parallel to [100]) of the six equivalent lowest conduction band valleys. When the electron affinity ? is the only parameter varied in the simulations, the value ? = 0.31 eV leads to overall qualitative agreement with the probability of emission deduced from experiments. Including band bending in the simulations improves the agreement with the experimental data, particularly at low applied fields, but not significantly. In this study, using surface potentials with different profiles further allows us to investigate the emission as a function of potential barrier height, width, and vacuum level position. However, adding surface patches with different levels of hydrogenation, modeled with position-dependent electron affinity, leads to the closest agreement with the experimental data.« less

  14. Modeling electron emission and surface effects from diamond cathodes

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

    Dimitrov, D. A. [Tech-X Corp., Boulder, CO (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smithe, D. [Tech-X Corp., Boulder, CO (United States); Cary, J. R. [Tech-X Corp., Boulder, CO (United States); Rao, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smedley, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, E. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-02-07

    We developed modeling capabilities, within the Vorpal particle-in-cell code, for three-dimensional (3D) simulations of surface effects and electron emission from semiconductor photocathodes. They include calculation of emission probabilities using general, piece-wise continuous, space-time dependent surface potentials, effective mass and band bending field effects. We applied these models, in combination with previously implemented capabilities for modeling charge generation and transport in diamond, to investigate the emission dependence on applied electric field in the range from approximately 2 MV/m to 17 MV/m along the [100] direction. The simulation results were compared to experimental data. For the considered parameter regime, conservation of transverse electron momentum (in the plane of the emission surface) allows direct emission from only two (parallel to [100]) of the six equivalent lowest conduction band valleys. When the electron affinity ? is the only parameter varied in the simulations, the value ? = 0.31 eV leads to overall qualitative agreement with the probability of emission deduced from experiments. Including band bending in the simulations improves the agreement with the experimental data, particularly at low applied fields, but not significantly. Using surface potentials with different profiles further allows us to investigate the emission as a function of potential barrier height, width, and vacuum level position. However, adding surface patches with different levels of hydrogenation, modeled with position-dependent electron affinity, leads to the closest agreement with the experimental data.

  15. Study of TFTR D-T neutron spectra using natural diamond detectors

    SciTech Connect (OSTI)

    Roquemore, A.L.; Krasilnikov, A.V., Gorelenkov, N.N.

    1996-12-31

    Three Natural Diamond Detector (NDD) based spectrometers have been used for neutron spectra measurement during Deuterium-Tritium (D-T) experiments using high power Neutral Beam Injection (NBI) and Ton Cyclotron Resonance Heating (ICRH) on the Tokamak Fusion Test Reactor (TFTR) in 1996. A 2-3 % energy resolution coupled with the high radiation resistance of NDDs (5 x 10{sup 14}n/cm{sup 2}) makes them ideal for measuring the D-T neutron spectra in the high radiation environment of TFTR tritium experiments. The compact size of the NDD made it possible to insert one of the detectors into one of the center channels of the TFTR multichannel neutron collimator to provide a vertical view perpendicular to the vessel midplane, Two other detectors were placed inside shields in TFTR test cell and provide measurements of the neutrons having angles of emission of 110- 180{degrees} and 60-12-{degrees} with respect to the direction of the plasma current. By using a 0.25 {mu}s shaping time of the Ortec 673 spectroscopy amplifier we were able to accumulate useful spectrometry data at count rates up to 1.5 x 10{sup 3} counts/sec. To model the D- T neutron spectra measured by each of three NDD`s the Neutron Source post TRANSP (NST) code and semi-analytical model were developed. A set of D-T and D-D plasmas is analyzed for the dynamics of D-T neutron spectral broadening for each of three NDD cones of view. The application of three NDD based D-T neutron -spectrometer array demonstrated the anisotropy of the ion distribution function. and provided a mature of the dynamics of the effective ion temperatures for each detector view, and determined the tangential velocity of resonant tritons during ICRH.

  16. You Cannot Press Out the Black Hole

    E-Print Network [OSTI]

    Daisuke Ida; Takahiro Okamoto

    2012-01-03

    It is shown that a ball-shaped black hole region homeomorphic with D**n cannot be pressed out, along whichever axis penetrating the black hole region, into a black ring with a doughnut-shaped black hole region homeomorphic with S**1 x D**(n-1). A more general prohibition law for the change of the topology of black holes, including a version of no-bifurcation theorems for black holes, is given.

  17. Black Stars and Gamma Ray Bursts

    E-Print Network [OSTI]

    Tanmay Vachaspati

    2007-06-08

    Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed ``black stars''. Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

  18. Ferromagnetic ordering of Cr and Fe doped p-type diamond: An ab initio study

    SciTech Connect (OSTI)

    Benecha, E. M.; Lombardi, E. B.

    2014-02-21

    Ferromagnetic ordering of transition metal dopants in semiconductors holds the prospect of combining the capabilities of semiconductors and magnetic systems in single hybrid devices for spintronic applications. Various semiconductors have so far been considered for spintronic applications, but low Curie temperatures have hindered room temperature applications. We report ab initio DFT calculations on the stability and magnetic properties of Fe and Cr impurities in diamond, and show that their ground state magnetic ordering and stabilization energies depend strongly on the charge state and type of co-doping. We predict that divacancy Cr{sup +2} and substitutional Fe{sup +1} order ferromagnetically in p-type diamond, with magnetic stabilization energies (and magnetic moment per impurity ion) of 16.9 meV (2.5 ?{sub B}) and 33.3 meV (1.0 ?{sub B}), respectively. These magnetic stabilization energies are much larger than what has been achieved in other semiconductors at comparable impurity concentrations, including the archetypal dilute magnetic semiconductor GaAs:Mn. In addition, substitutional Fe{sup +1} exhibits a strong half-metallic character, with the Fermi level crossing bands in only the spin down channel. These results, combined with diamond’s extreme properties, demonstrate that Cr or Fe dopedp-type diamond may successfully be considered in the search for room temperature spintronic materials.

  19. Diamond-anvil high-pressure cell with improved x-ray collimation system

    DOE Patents [OSTI]

    Schiferl, D.; Olinger, B.W.; Livingston, R.W.

    1984-03-30

    An adjustable x-ray collimation system for a diamond-anvil high-pressure cell of the type including a cooperable piston and cylinder and a pair of opposing diamonds located between the head of the piston and the head of the cylinder. The x-ray collimation system includes a tubular insert which contains an x-ray collimator. The insert is engageable in the bore of the piston. The collimator is mounted within the insert by means of an elastomeric o-ring at the end closest the opposed diamonds, and by means of a set of adjustable set screws at the opposite end. By adjustment of the set screws the collimator can be pivoted about the o-ring and brought into alignment with the opposed diamonds and the sample contained therein. In the preferred embodiment there is further provided a set of plugs which are insertable in the bore of the collimator. The plugs have bores of different diameters. By successively inserting plugs of progressively smaller bore diameters and adjusting the alignment of the collimator with each plug, the collimator can be quickly brought into accurate alignment with the diamonds. The collimation system allows alignment of the collimator either before or after the cell has been loaded and pressurized.

  20. Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications.

    SciTech Connect (OSTI)

    Swain; Greg M.

    2009-04-13

    The original funding under this project number was awarded for a period 12/1999 until 12/2002 under the project title Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications. The project was extended until 06/2003 at which time a renewal proposal was awarded for a period 06/2003 until 06/2008 under the project title Metal/Diamond Composite Thin-Film Electrodes: New Carbon Supported Catalytic Electrodes. The work under DE-FG02-01ER15120 was initiated about the time the PI moved his research group from the Department of Chemistry at Utah State University to the Department of Chemistry at Michigan State University. This DOE-funded research was focused on (i) understanding structure-function relationships at boron-doped diamond thin-film electrodes, (ii) understanding metal phase formation on diamond thin films and developing electrochemical approaches for producing highly dispersed electrocatalyst particles (e.g., Pt) of small nominal particle size, (iii) studying the electrochemical activity of the electrocatalytic electrodes for hydrogen oxidation and oxygen reduction and (iv) conducting the initial synthesis of high surface area diamond powders and evaluating their electrical and electrochemical properties when mixed with a Teflon binder.

  1. Black Holes of Negative Mass

    E-Print Network [OSTI]

    R. B. Mann

    1997-05-06

    I demonstrate that, under certain circumstances, regions of negative energy density can undergo gravitational collapse into a black hole. The resultant exterior black hole spacetimes necessarily have negative mass and non-trivial topology. A full theory of quantum gravity, in which topology-changing processes take place, could give rise to such spacetimes.

  2. A Ni/surface-modified Diamond Composite Electroplating Coating on Superelastic NiTi Alloy as Potential Dental Bur Design

    E-Print Network [OSTI]

    Zheng, Yufeng

    A Ni/surface-modified Diamond Composite Electroplating Coating on Superelastic NiTi Alloy: Composite Electroplating; Surface-modified Diamond Particles; Interfacial Adhesion; NiTi alloy; Dental Bur into nickel coating, and its shank made of stainless steel. There are strong demands from the dentist

  3. Seasonal steroid hormone levels and their relation to reproduction in the Western Diamond-backed Rattlesnake, Crotalus

    E-Print Network [OSTI]

    Taylor, Emily

    Seasonal steroid hormone levels and their relation to reproduction in the Western Diamond-backed levels in blood samples from free-ranging Western Diamond-backed Rattle- snakes (Crotalus atrox physiology, from under- standing basic mechanisms to designing treatments for reproductive dysfunction

  4. Inkjet printing of nanodiamond suspensions in ethylene glycol for CVD growth of patterned diamond structures and practical applications

    E-Print Network [OSTI]

    Wilamowski, Bogdan Maciej

    Inkjet printing of nanodiamond suspensions in ethylene glycol for CVD growth of patterned diamond Available online 26 October 2008 Keywords: Inkjet Printing Diamond Nanodiamond Patterns Fabrication on a rigid or flexible substrate. In this work, nanodiamond suspensions in ethylene glycol were used as inks

  5. AlTiN layer effect on mechanical properties of Ti-doped diamond-like carbon composite coatings

    E-Print Network [OSTI]

    Volinsky, Alex A.

    AlTiN layer effect on mechanical properties of Ti-doped diamond-like carbon composite coatings Adhesion Ti/Ti-doped diamond-like carbon (DLC) and Ti/AlTiN/Ti-DLC composite coatings were deposited on the properties of these composite coatings was investigated through microstructure and mechanical properties

  6. High-temperature electron emission from diamond films Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee 37235

    E-Print Network [OSTI]

    Walker, D. Greg

    High-temperature electron emission from diamond films S. H. Shin Department of Mechanical This work examines electron field-emission characteristics of polycrystalline diamond films at elevated-enhanced chemical-vapor deposition. To investigate the effect of increased temperatures on field emission, current

  7. Optical properties of polycrystalline diamond films in the far-infrared A. J. Gatesman, R. H. Giles, J. Waldman

    E-Print Network [OSTI]

    Massachusetts at Lowell, University of

    spurred interest in the growth and production of high quality diamond films for a variety of electrical and optical applications. Potential uses for vapor grown diamond include optical coatings and windows, heatTorr Deposition Pressure 50 Torr Substrate Temperature 875 - 950 C Hydrogen Flow 250 - 500 sccm Methane Flow 2 - 5

  8. Effects of thickness and cycle parameters on fretting wear behavior of CVD diamond coatings on steel substrates

    E-Print Network [OSTI]

    Bristol, University of

    , mechanical seals, cutting tools, and gears. Well-adhered diamond films deposited on steel surfaces can leadEffects of thickness and cycle parameters on fretting wear behavior of CVD diamond coatings) methods. A Co-containing tungsten-carbide coating prepared by high velocity oxy-fuel spraying was used

  9. Black hole feedback in the luminous quasar PDS 456

    E-Print Network [OSTI]

    Nardini, E; Gofford, J; Harrison, F A; Risaliti, G; Braito, V; Costa, M T; Matzeu, G A; Walton, D J; Behar, E; Boggs, S E; Christensen, F E; Craig, W W; Hailey, C J; Matt, G; Miller, J M; O'Brien, P T; Stern, D; Turner, T J; Ward, M J

    2015-01-01

    The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different epochs, we detected the signatures of a nearly spherical stream of highly ionized gas in the broadband X-ray spectra of the luminous quasar PDS 456. This persistent wind is expelled at relativistic speeds from the inner accretion disk, and its wide aperture suggests an effective coupling with the ambient gas. The outflow's kinetic power larger than 10^46 ergs per second is enough to provide the feedback required by models of black hole and host galaxy co-evolution.

  10. The Development of Open Water-lubricated Polycrystalline Diamond (PCD) Thrust Bearings for Use in Marine Hydrokinetic (MHK) Energy Machines

    SciTech Connect (OSTI)

    Cooley, Craig, H.; Khonsari, Michael,, M; Lingwall, Brent

    2012-11-28

    Polycrstalline diamond (PCD) bearings were designed, fabricated and tested for marine-hydro-kinetic (MHK) application. Bearing efficiency and life were evaluated using the US Synthetic bearing test facility. Three iterations of design, build and test were conducted to arrive at the best bearing design. In addition life testing that simulated the starting and stopping and the loading of real MHK applications were performed. Results showed polycrystalline diamond bearings are well suited for MHK applications and that diamond bearing technology is TRL4 ready. Based on life tests results bearing life is estimated to be at least 11.5 years. A calculation method for evaluating the performance of diamond bearings of round geometry was also investigated and developed. Finally, as part of this effort test bearings were supplied free of charge to the University of Alaska for further evaluation. The University of Alaska test program will subject the diamond bearings to sediment laden lubricating fluid.

  11. Development of Designer Diamond Technology for High Pressure High Temperature Experiments in Support of Stockpile Stewardship Program

    SciTech Connect (OSTI)

    Vohra, Yogesh, K.

    2009-10-28

    The role of nitrogen in the fabrication of designer diamond was systematically investigated by adding controlled amount of nitrogen in hydrogen/methane/oxygen plasma. This has led to a successful recipe for reproducible fabrication of designer diamond anvils for high-pressure high-temperature research in support of stockpile stewardship program. In the three-year support period, several designer diamonds fabricated with this new growth chemistry were utilized in high-pressure experiments at UAB and Lawrence Livermore National Laboratory. The designer diamond anvils were utilized in high-pressure studies on heavy rare earth metals, high pressure melting studies on metals, and electrical resistance measurements on iron-based layered superconductors under high pressures. The growth chemistry developed under NNSA support can be adapted for commercial production of designer diamonds.

  12. Metal/Diamond Composite Thin-Film Electrodes: New Carbon Supported Catalytic Electrodes

    SciTech Connect (OSTI)

    Greg M. Swain, PI

    2009-03-10

    The DOE-funded research conducted by the Swain group was focused on (i) understanding structure-function relationships at boron-doped diamond thin-film electrodes, (ii) understanding metal phase formation on diamond thin films and developing electrochemical approaches for producing highly dispersed electrocatalyst particles (e.g., Pt) of small nominal particle size, (iii) studying the electrochemical activity of the electrocatalytic electrodes for hydrogen oxidation and oxygen reduction and (iv) conducting the initial synthesis of high surface area diamond powders and evaluating their electrical and electrochemical properties when mixed with a Teflon binder. (Note: All potentials are reported versus Ag/AgCl (sat'd KCl) and cm{sup 2} refers to the electrode geometric area, unless otherwise stated).

  13. Ultraviolet photosensitivity of sulfur-doped micro- and nano-crystalline diamond

    SciTech Connect (OSTI)

    Mendoza, Frank; Makarov, Vladimir; Hidalgo, Arturo; Weiner, Brad; Morell, Gerardo

    2011-06-06

    The room-temperature photosensitivity of sulfur-doped micro- (MCD), submicro- (SMCD) and nano- (NCD) crystalline diamond films synthesized by hot-filament chemical vapor deposition was studied. The structure and composition of these diamond materials were characterized by Raman spectroscopy, scanning electron microscopy and X-ray diffraction. The UV sensitivity and response time were studied for the three types of diamond materials using a steady state broad UV excitation source and two pulsed UV laser radiations. It was found that they have high sensitivity in the UV region, as high as 109 sec-1mV-1 range, linear response in a broad spectral range below 320 nm, photocurrents around ~10-5 A, and short response time better than 100 ns, which is independent of fluency intensity. A phenomenological model was applied to help understand the role of defects and dopant concentration on the materials’ photosensitivity.

  14. Ultraviolet photosensitivity of sulfur-doped micro- and nano-crystalline diamond

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

    Mendoza, Frank; Makarov, Vladimir; Hidalgo, Arturo; Weiner, Brad; Morell, Gerardo

    2011-06-06

    The room-temperature photosensitivity of sulfur-doped micro- (MCD), submicro- (SMCD) and nano- (NCD) crystalline diamond films synthesized by hot-filament chemical vapor deposition was studied. The structure and composition of these diamond materials were characterized by Raman spectroscopy, scanning electron microscopy and X-ray diffraction. The UV sensitivity and response time were studied for the three types of diamond materials using a steady state broad UV excitation source and two pulsed UV laser radiations. It was found that they have high sensitivity in the UV region, as high as 109 sec-1mV-1 range, linear response in a broad spectral range below 320 nm, photocurrentsmore »around ~10-5 A, and short response time better than 100 ns, which is independent of fluency intensity. A phenomenological model was applied to help understand the role of defects and dopant concentration on the materials’ photosensitivity.« less

  15. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    SciTech Connect (OSTI)

    Harris Kagan; K.K. Gan; Richard Kass

    2009-03-31

    Diamond was studied as a possible radiation hard technology for use in future high radiation environments. With the commissioning of the LHC expected in 2009, and the LHC upgrades expected in 2013, all LHC experiments are planning for detector upgrades which require radiation hard technologies. Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle and CDF and is installed in all LHC experiments. As a result, this material is now being discussed as an alternative sensor material for tracking very close to the interaction region of the super-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications.

  16. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    SciTech Connect (OSTI)

    Rainer Wallny

    2012-10-15

    Diamond was studied as a possible radiation hard technology for use in future high radiation environments. With the commissioning of the LHC expected in 2010, and the LHC upgrades expected in 2015, all LHC experiments are planning for detector upgrades which require radiation hard technologies. Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle and CDF and is installed and operational in all LHC experiments. As a result, this material is now being discussed as an alternative sensor material for tracking very close to the interaction region of the super-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications.

  17. Numerical Modeling on Thermal Loading of Diamond Crystal in X-ray FEL Oscillator

    E-Print Network [OSTI]

    Song, Meiqi; Guo, Yuhang; Li, Kai; Deng, Haixiao

    2015-01-01

    Due to high reflectivity and high resolution to X-ray pulse, diamond is one of the most popular Bragg crystals serving as the reflecting mirror and mono-chromator in the next generation free electrons lasers (FELs). The energy deposition of X-rays will result in thermal heating, and thus lattice expanding of diamond crystal, which may degrade the performance of X-ray FELs. In this paper, the thermal loading effect of diamond crystal for X-ray FEL oscillator has been systematically studied by the combined simulation of Geant4 and ANSYS, and its dependence on the environment temperature, crystal size, X-ray pulse repetition rate and pulse energy are presented.

  18. MEASUREMENT OF THE SECONDARY EMISSION YIELD OF A THIN DIAMOND WINDOW IN TRANSMISSION MODE.

    SciTech Connect (OSTI)

    CHANG, X.; RAO, T.; SMEDLEY, J.; ET AL.

    2005-05-16

    The secondary emission enhanced photoinjector (SEEP) is a promising new approach to the generation of high-current, high-brightness electron beams. A low current primary electron beam with energy of a few thousand electron-volts strikes a specially prepared diamond window which emits secondary electrons with a current two orders of magnitude higher. The secondary electrons are created at the back side of the diamond and drift through the window under the influence of a strong electrical field. A hydrogen termination at the exit surface of the window creates a negative electron affinity (NEA) which allows the electrons to leave the diamond. An experiment was performed to measure the secondary electron yield and other properties. The results are discussed in this paper.

  19. Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices.

    SciTech Connect (OSTI)

    Auciello, O.; Gruen, D. M.; Krauss, A. R.; Jayatissa, A.; Sumant, A.; Tucek, J.; Mancini, D.; Moldovan, N.; Erdemir, A.; Ersoy, D.; Gardos, M. N.; Busmann, H. G.; Meyer, E. M.

    2000-11-15

    MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties, and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors, However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophyllic surfaces, even these simple devices have limited dynamic range. Future MEMS applications that involve significant rolling or sliding contact will require the use of new materials with significantly improved mechanical and tribological properties, and the ability to perform well in harsh environments. Diamond is a superhard material of high mechanical strength, exceptional chemical inertness, and outstanding thermal stability. The brittle fracture strength is 23 times that of Si, and the projected wear life of diamond MEMS moving mechanical assemblies (MEMS-MMAS) is 10,000 times greater than that of Si MMAs. However, as the hardest known material, diamond is notoriously difficult to fabricate. Conventional CVD thin film deposition methods offer an approach to the fabrication of ultra-small diamond structures, but the films have large grain size, high internal stress, poor intergranular adhesion, and very rough surfaces, and are consequently ill-suited for MEMS-MMA applications. A thin film deposition process has been developed that produces phase-pure ultrananocrystalline diamond (UNCD) with morphological and mechanical properties that are ideally suited for MEMS applications in general, and MMA use in particular. We have developed lithographic techniques for the fabrication of diamond microstructure including cantilevers and multi-level devices, acting as precursors to micro-bearings and gears, making UNCD a promising material for the development of high performance MEMS devices.

  20. Constraining Black Hole Spin Via X-ray Spectroscopy

    E-Print Network [OSTI]

    Laura W. Brenneman; Christopher S. Reynolds

    2006-08-23

    We present an analysis of the observed broad iron line feature and putative warm absorber in the long 2001 XMM-Newton observation of the Seyfert-1.2 galaxy MCG-6-30-15. The new "kerrdisk" model we have designed for simulating line emission from accretion disk systems allows black hole spin to be a free parameter in the fit, enabling the user to formally constrain the angular momentum of a black hole, among other physical parameters of the system. In an important extension of previous work, we derive constraints on the black hole spin in MCG-6-30-15 using a self-consistent model for X-ray reflection from the surface of the accretion disk while simultaneously accounting for absorption by dusty photoionized material along the line of sight (the warm absorber). Even including these complications, the XMM-Newton/EPIC-pn data require extreme relativistic broadening of the X-ray reflection spectrum; assuming no emission from within the radius of marginal stability, we derive a formal constraint on the dimensionless black hole spin parameter of a > 0.987 at 90% confidence. The principal unmodeled effect that can significantly reduce the inferred black hole spin is powerful emission from within the radius of marginal stability. Although significant theoretical developments are required to fully understand this region, we argue that the need for a rapidly spinning black hole is robust to physically plausible levels of emission from within the radius of marginal stability. In particular, we show that a non-rotating black hole is strongly ruled out.

  1. Synthesis of new Diamond-like B-C Phases under High Pressure and Temperatures

    SciTech Connect (OSTI)

    Ming, L. C.; Zinin, P. V.; Sharma, S. K.

    2014-04-22

    A cubic BC3 (c-BC3) phase was synthesized by direct transformation from graphitic phases at a pressure of 39 GPa and temperature of 2200 K in a laser-heated diamond anvil cell (DAC). A combination of x-ray diffraction (XRD), electron diffraction (ED), transmission electron microscopy (TEM) imaging, and electron energy loss spectroscopy (EELS) measurements lead us to conclude that the obtained phase is hetero-nano-diamond, c-BC3. The EELS measurements show that the atoms inside the cubic structure are bonded by sp3 bonds.

  2. Design of flexible ultrahigh-Q microcavities in diamond-based photonic crystal slabs

    E-Print Network [OSTI]

    Snjezana Tomljenovic-Hanic; Andrew D. Greentree; C. Martijn de Sterke; Steven Prawer

    2008-12-10

    We design extremely flexible ultrahigh-Q diamond-based double-heterostructure photonic crystal slab cavities by modifying the refractive index of the diamond. The refractive index changes needed for ultrahigh-Q cavities with $Q ~ 10^7$, are well within what can be achieved ($\\Delta n \\sim 0.02$). The cavity modes have relatively small volumes $Vdesign is flexible because the range of parameters, cavity length and the index changes, that enables an ultrahigh-Q is quite broad. Furthermore as the index modification is post-processed, an efficient technique to generate cavities around defect centres is achievable, improving prospects for defect-tolerant quantum architectures.

  3. Field emission from bias-grown diamond thin films in a microwave plasma

    DOE Patents [OSTI]

    Gruen, Dieter M. (Downers Grove, IL); Krauss, Alan R. (Naperville, IL); Ding, Ming Q. (Beijing, CN); Auciello, Orlando (Bolinbrook, IL)

    2002-01-01

    A method of producing diamond or diamond like films in which a negative bias is established on a substrate with an electrically conductive surface in a microwave plasma chemical vapor deposition system. The atmosphere that is subjected to microwave energy includes a source of carbon, nitrogen and hydrogen. The negative bias is maintained on the substrate through both the nucleation and growth phase of the film until the film is continuous. Biases between -100V and -200 are preferred. Carbon sources may be one or more of CH.sub.4, C.sub.2 H.sub.2 other hydrocarbons and fullerenes.

  4. Longitudinal spin-relaxation in nitrogen-vacancy centers in electron irradiated diamond

    E-Print Network [OSTI]

    A. Jarmola; A. Berzins; J. Smits; K. Smits; J. Prikulis; F. Gahbauer; R. Ferber; D. Erts; M. Auzinsh; D. Budker

    2015-11-19

    We present systematic measurements of longitudinal relaxation rates ($1/T_1$) of spin polarization in the ground state of the nitrogen-vacancy (NV$^-$) color center in synthetic diamond as a function of NV$^-$ concentration and magnetic field $B$. NV$^-$ centers were created by irradiating a Type 1b single-crystal diamond along the [100] axis with 200 keV electrons from a transmission electron microscope with varying doses to achieve spots of different NV$^-$ center concentrations. Values of ($1/T_1$) were measured for each spot as a function of $B$.

  5. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Lodato, G; Lodato, Giuseppe; Natarajan, Priyamvada

    2007-01-01

    In this paper we derive the mass function of seed black holes that result from the central mass concentrated via disc accretion in collapsed haloes at redshift $z\\approx 15$. Using standard arguments including stability, we show that these pre-galactic discs can assemble a significant mass concentration in the inner regions, providing fuel for the formation and initial growth of super-massive black holes. Assuming that these mass concentrations do result in central seed black holes, we determine the mass distribution of these seeds as a function of key halo properties. The seed mass distribution determined here turns out to be asymmetric and skewed to higher masses. Starting with these initial seeds, building up to $10^9$ solar masses by $z = 6$ to power the bright quasars is not a problem in the standard LCDM cosmogony. These seed black holes in gas rich environments are likely to grow into the supermassive black holes at later times via mergers and accretion. Gas accretion onto these seeds at high redshift ...

  6. Dark Matter Hawking Radiation? Dark Spinors Tunnelling in String Theory Black Holes

    E-Print Network [OSTI]

    Cavalcanti, R T

    2015-01-01

    The Hawking radiation spectrum of Kerr-Sen axion-dilaton black holes is derived, in the context of dark spinors tunnelling across the horizon. Since a black hole has a well defined temperature, it should radiate in principle all the standard model particles, similar to a black body at that temperature. We investigate the tunnelling of mass dimension one spin-1/2 dark fermions, that are beyond the standard model and are prime candidates to the dark matter. Their interactions with the standard model matter and gauge fields are suppressed by at least one power of unification scale, being restricted just to the Higgs field and to the graviton likewise. The tunnelling method for the emission and absorption of mass dimension one particles across the event horizon of Kerr-Sen axion-dilaton black holes is shown here to provide further evidence for the universality of black hole radiation, further encompassing particles beyond the standard model.

  7. Dark Matter Hawking Radiation? Dark Spinors Tunnelling in String Theory Black Holes

    E-Print Network [OSTI]

    R. T. Cavalcanti; Roldao da Rocha

    2015-07-14

    The Hawking radiation spectrum of Kerr-Sen axion-dilaton black holes is derived, in the context of dark spinors tunnelling across the horizon. Since a black hole has a well defined temperature, it should radiate in principle all the standard model particles, similar to a black body at that temperature. We investigate the tunnelling of mass dimension one spin-1/2 dark fermions, that are beyond the standard model and are prime candidates to the dark matter. Their interactions with the standard model matter and gauge fields are suppressed by at least one power of unification scale, being restricted just to the Higgs field and to the graviton likewise. The tunnelling method for the emission and absorption of mass dimension one particles across the event horizon of Kerr-Sen axion-dilaton black holes is shown here to provide further evidence for the universality of black hole radiation, further encompassing particles beyond the standard model.

  8. The Association of Jet Production with Geometrically Thick Accretion Flows and Black Hole Rotation

    E-Print Network [OSTI]

    David L. Meier

    2000-10-12

    A model is presented in which the strongest radio-emitting jet outflows are produced in black hole systems when the accretion is a geometrically thick ($H/R \\sim 1$) inflow ({\\it e.g.}, ADAF, CDAF) {\\em and} if the black hole is rotating. For galactic black hole candidates, the model naturally accounts for the observed correlation of jet outflow with the black hole hard emission state and predicts an association of strong jets with rapid black hole rotation. When extended to the supermassive case, the model accounts for the highest radio galaxy and quasar jet powers and provides additional theoretical support for the ``spin paradigm'', which asserts that radio loud quasars are produced by Kerr holes and radio quiet ones by Schwarzschild holes. In some cases, the angular momentum and energy outflow in the jet may be large enough to significantly alter the structure of the accretion flow from that predicted by current models.

  9. Strings, higher curvature corrections, and black holes

    E-Print Network [OSTI]

    Thomas Mohaupt

    2005-12-05

    We review old and recent results on subleading contributions to black hole entropy in string theory.

  10. Physics: the big black box Mirror conjecture

    E-Print Network [OSTI]

    Cavalieri, Renzo

    Physics: the big black box Math Mirror conjecture A look into the mirror (I) an overview of Mirror Symmetry #12;Physics: the big black box Math Mirror conjecture Outline 1 Physics: the big black box 2 Math Symmetry #12;Physics: the big black box Math Mirror conjecture A slogan Mirror Symmetry is a correspondence

  11. Black hole horizons Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    on a black hole: up to 42% of the mass-energy mc2 of accreted matter ! NB: thermonuclear reactions release: a very deep gravitational potential well Release of potential gravitational energy by accretion

  12. Thermodynamics of regular black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Yong-Wan Kim; Young-Jai Park

    2008-09-21

    We investigate thermodynamics for a magnetically charged regular black hole (MCRBH), which comes from the action of general relativity and nonlinear electromagnetics, comparing with the Reissner-Norstr\\"om (RN) black hole in both four and two dimensions after dimensional reduction. We find that there is no thermodynamic difference between the regular and RN black holes for a fixed charge $Q$ in both dimensions. This means that the condition for either singularity or regularity at the origin of coordinate does not affect the thermodynamics of black hole. Furthermore, we describe the near-horizon AdS$_2$ thermodynamics of the MCRBH with the connection of the Jackiw-Teitelboim theory. We also identify the near-horizon entropy as the statistical entropy by using the AdS$_2$/CFT$_1$ correspondence.

  13. Black Holes and Nuclear Dynamics

    E-Print Network [OSTI]

    David Merritt

    2006-02-17

    Supermassive black holes inhabit galactic nuclei, and their presence influences in crucial ways the evolution of the stellar distribution. The low-density cores observed in bright galaxies are probably a result of black hole infall, while steep density cusps like those at the Galactic center are a result of energy exchange between stars moving in the gravitational field of the single black hole. Loss-cone dynamics are substantially more complex in galactic nuclei than in collisionally-relaxed systems like globular clusters due to the wider variety of possible geometries and orbital populations. The rate of star-black hole interactions has begun to be constrained through observations of energetic events associated with stellar tidal disruptions.

  14. Measurement of Mass and Spin of Black Holes with QPOs

    E-Print Network [OSTI]

    B. Aschenbach

    2007-10-18

    There are now four low mass X-ray binaries with black holes which show twin resonant-like HFQPOs. Similar QPOs might have been found in Sgr A*. I review the power spectral density distributions of the three X-ray flares and the six NIR flares published for Sgr A* so far, in order to look for more similarities than just the frequencies between the microquasar black holes and Sgr A*. The three X-ray flares of Sgr A* are re-analysed in an identical way and white noise probabilities from their power density distributions are given for the periods reported around 1100 s. Progress of the resonant theory using the anomalous orbital velocity effect is summarized.

  15. Comparison of Wide-Bandgap Semiconductors for Power Electronics Applications

    SciTech Connect (OSTI)

    Ozpineci, B.

    2004-01-02

    Recent developmental advances have allowed silicon (Si) semiconductor technology to approach the theoretical limits of the Si material; however, power device requirements for many applications are at a point that the present Si-based power devices cannot handle. The requirements include higher blocking voltages, switching frequencies, efficiency, and reliability. To overcome these limitations, new semiconductor materials for power device applications are needed. For high power requirements, wide-bandgap semiconductors like silicon carbide (SiC), gallium nitride (GaN), and diamond, with their superior electrical properties, are likely candidates to replace Si in the near future. This report compares wide-bandgap semiconductors with respect to their promise and applicability for power applications and predicts the future of power device semiconductor materials.

  16. Ultratough, Thermally Stable Polycrystalline Diamond/Silicon Carbide Nanocomposites for Drill Bits

    SciTech Connect (OSTI)

    2009-03-01

    This factsheet describes a research project whose goal is to develop and produce in quantity novel superhard and ultratough thermally stable polycrystalline (TSP) diamond/SiC nanocomposites reinforced with SiC/C nanofibers for drill-bit applications and multiple industrial functions.

  17. Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear

    DOE Patents [OSTI]

    Westerfield, Curtis L. (Espanola, NM); Morris, John S. (Los Alamos, NM); Agnew, Stephen F. (Los Alamos, NM)

    1997-01-01

    Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear. A cell is described which, in combination with Fourier transform IR spectroscopy, permits the spectroscopic investigation of boundary layers under conditions of high temperature, high pressure and shear.

  18. Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear

    DOE Patents [OSTI]

    Westerfield, C.L.; Morris, J.S.; Agnew, S.F.

    1997-01-14

    Diamond anvil cell is described for spectroscopic investigation of materials at high temperature, high pressure and shear. A cell is described which, in combination with Fourier transform IR spectroscopy, permits the spectroscopic investigation of boundary layers under conditions of high temperature, high pressure and shear. 4 figs.

  19. Multiple scales of diamond mining in Akwatia, Ghana: addressing environmental and human development impact

    E-Print Network [OSTI]

    Vermont, University of

    impact on environmental degradation, health, and the livelihood of artisanal miners. We concludeMultiple scales of diamond mining in Akwatia, Ghana: addressing environmental and human development impact Kaakpema Yelpaalaa,b , Saleem H. Alic,d, * a Yale University, School of Epidemiology and Public

  20. Chapter 2.20 Msink20 Diamond Seeding & Lift-off (General Solvent Sink)

    E-Print Network [OSTI]

    Healy, Kevin Edward

    Chapter 2.20 Msink20 Diamond Seeding & Lift-off (General Solvent Sink) (msink20) (582A) 1/eyewash station at the east side of Rm. 582A (polisher/wet lab area); to activate the shower pull down Operation 8.1 Two ultrasonic baths- plus user-owned setups- are stationed on the deck of this sink. The left

  1. Chemically vapor deposited diamond-tipped one-dimensional nanostructures and nanodiamondsilicananotube composites

    E-Print Network [OSTI]

    Wilamowski, Bogdan Maciej

    Chemically vapor deposited diamond-tipped one-dimensional nanostructures and nanodiamond vapor deposition Composite thin films of nanodiamond and silica nanotubes were synthesized by means with nanodiamond particles. SEM, Raman spectroscopy, and EDX were used to analyze the composite. Wet chemical

  2. Slide diamond burnishing of tool steels with adhesive coatings and diffusion layers

    E-Print Network [OSTI]

    North Texas, University of

    Slide diamond burnishing of tool steels with adhesive coatings and diffusion layers W. Brostow*1 modification of selected tool steels. The steels were covered with adhesive coatings of the hard chrome type was determined by a profilometer before and after burnishing. Adhesion of coatings to steel was determined

  3. Automated Testing of HVAC Systems for Commissioning Tim Salsbury and Rick Diamond

    E-Print Network [OSTI]

    Diamond, Richard

    carrying out a proof of operation. In large modern buildings, the energy management and control system monitoring period following each change in setpoint, characterize system performance. These indicesAutomated Testing of HVAC Systems for Commissioning Tim Salsbury and Rick Diamond Lawrence Berkeley

  4. WM00 Conference, February 27-March 2, 2000 DEMONSTRATING DIAMOND WIRE CUTTING OF THE TFTR

    E-Print Network [OSTI]

    task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration: The baseline planning for dismantling the vacuum vessel utilizes plasma arc torch cutting. This involves

  5. Propagation and absorption of high-intensity femtosecond laser radiation in diamond

    SciTech Connect (OSTI)

    Kononenko, V V; Konov, V I; Gololobov, V M; Zavedeev, E V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-12-31

    Femtosecond interferometry has been used to experimentally study the photoexcitation of the electron subsystem of diamond exposed to femtosecond laser pulses of intensity 10{sup 11} to 10{sup 14} W cm{sup -2}. The carrier concentration has been determined as a function of incident intensity for three harmonics of a Ti : sapphire laser (800, 400 and 266 nm). The results demonstrate that, in a wide range of laser fluences (up to those resulting in surface and bulk graphitisation), a well-defined multiphoton absorption prevails. We have estimated nonlinear absorption coefficients for pulsed radiation at ? = 800 nm (four-photon transition) and at 400 and 266 nm (indirect and direct two-photon transitions, respectively). It has also been shown that, at any considerable path length of a femtosecond pulse in diamond (tens of microns or longer), the laser beam experiences a severe nonlinear transformation, determining the amount of energy absorbed by the lattice, which is important for the development of technology for diamond photostructuring by ultrashort pulses. The competition between wave packet self-focusing and the plasma defocusing effect is examined as a major mechanism governing the propagation of intense laser pulses in diamond. (interaction of laser radiation with matter. laser plasma)

  6. Eclogitic Diamond Formation at Jwaneng: No Room for a Recycled Component

    E-Print Network [OSTI]

    Cartigny, Pierre

    and chemistry and the volatiles of the Earth's mantle (1, 2). Two main diamond types are identified on the basis (but chemically distinct) to either oli- vine-bearing peridotites or eclogites and are commonly. On the basis of the mea- sured 13 C values (12), we selected 31 sili- cate-bearing and 9 sulfide-bearing dia

  7. High surface area diamond-like carbon electrodes grown on vertically aligned carbon nanotubes

    E-Print Network [OSTI]

    Bristol, University of

    High surface area diamond-like carbon electrodes grown on vertically aligned carbon nanotubes H packed forests of vertically aligned multiwall carbon nanotubes (VACNTs). The DLC:VACNT composite film and high corrosion resistance [13,14]. Other type of dopants, including nickel and boron, also result

  8. Method to grow pure nanocrystalline diamond films at low temperatures and high deposition rates

    DOE Patents [OSTI]

    Carlisle, John A. (Plainfield, IL); Gruen, Dieter M. (Downers Grove, IL); Auciello, Orlando (Bolingbrook, IL); Xiao, Xingcheng (Woodridge, IL)

    2009-07-07

    A method of depositing nanocrystalline diamond film on a substrate at a rate of not less than about 0.2 microns/hour at a substrate temperature less than about 500.degree. C. The method includes seeding the substrate surface with nanocrystalline diamond powder to an areal density of not less than about 10.sup.10sites/cm.sup.2, and contacting the seeded substrate surface with a gas of about 99% by volume of an inert gas other than helium and about 1% by volume of methane or hydrogen and one or more of acetylene, fullerene and anthracene in the presence of a microwave induced plasma while maintaining the substrate temperature less than about 500.degree. C. to deposit nanocrystalline diamond on the seeded substrate surface at a rate not less than about 0.2 microns/hour. Coatings of nanocrystalline diamond with average particle diameters of less than about 20 nanometers can be deposited with thermal budgets of 500.degree. C.-4 hours or less onto a variety of substrates such as MEMS devices.

  9. High quality factor nanocrystalline diamond micromechanical resonators limited by thermoelastic damping

    SciTech Connect (OSTI)

    Najar, Hadi; Chan, Mei-Lin; Yang, Hsueh-An; Lin, Liwei; Cahill, David G.; Horsley, David A.

    2014-04-14

    We demonstrate high quality factor thin-film nanocrystalline diamond micromechanical resonators with quality factors limited by thermoelastic damping. Cantilevers, single-anchored and double-anchored double-ended tuning forks, were fabricated from 2.5??m thick in-situ boron doped nanocrystalline diamond films deposited using hot filament chemical vapor deposition. Thermal conductivity measured by time-domain thermoreflectance resulted in 24?±?3?W m{sup ?1} K{sup ?1} for heat transport through the thickness of the diamond film. The resonant frequencies of the fabricated resonators were 46?kHz–8?MHz and showed a maximum measured Q???86?000 at f{sub n}?=?46.849?kHz. The measured Q-factors are shown to be in good agreement with the limit imposed by thermoelastic dissipation calculated using the measured thermal conductivity. The mechanical properties extracted from resonant frequency measurements indicate a Young's elastic modulus of ?788?GPa, close to that of microcrystalline diamond.

  10. Graphene-on-Diamond Devices with Increased Current-Carrying Capacity: Carbon sp2

    E-Print Network [OSTI]

    Graphene-on-Diamond Devices with Increased Current-Carrying Capacity: Carbon sp2 -on-sp3 Technology Laboratory, Illinois 60439, United States *S Supporting Information ABSTRACT: Graphene demonstrated potential for practical applications owing to its excellent electronic and thermal properties. Typical graphene field

  11. Atomistic modeling of the fracture of polycrystalline diamond O. A. Shenderova and D. W. Brenner

    E-Print Network [OSTI]

    Brenner, Donald W.

    Atomistic modeling of the fracture of polycrystalline diamond O. A. Shenderova and D. W. Brenner for fracture, maximum stresses and strains, and toughness as a function of GB type are evaluated. Results With strength values ranging between 180 and 5190 MPa, and fracture toughness between 5.3 and 8 MN m 3/2 ,1

  12. Black Boundary Lines: Race, Class and Gender among Black Undergraduate Students

    E-Print Network [OSTI]

    Morales, Erica

    2012-01-01

    C. 1994. Behind the Mule: Race and Class in African AmericanHarlemworld: Doing Race and Class in Contemporary BlackBlue-Chip Black: Race, Class and Status in the New Black

  13. Fishing in Black Holes

    E-Print Network [OSTI]

    A. Brotas

    2006-09-01

    The coordinate system $(\\bar{x},\\bar{t})$ defined by $r = 2m + K\\bar{x}- c K \\bar{t}$ and $t=\\bar{x}/cK - 1 /cK \\int_{r_a}^r (1- 2m/r + K^2)^{1/2} (1 - 2m/r)^{-1}dr$ allow us to write the Schwarzschild metric in the form: \\[ds^2=c^2 d\\bar{t}^2 + (W^2/K^2 - 2W/K) d\\bar{x}^2 + 2c (1 + W/K) d\\bar{x}d\\bar{t} - r^2 (d\\theta^2 + cos^2\\theta d\\phi^2)\\] with $W=(1 - 2m/r + K^2)^{1/2}$, in which the coefficients' pathologies are moved to $r_K = 2m/(1+K^2)$. This new coordinate system is used to study the entrance into a black hole of a rigid line (a line in which the shock waves propagate with velocity c).

  14. Nano-hillock formation in diamond-like carbon induced by swift heavy projectiles in the electronic stopping regime: Experiments and atomistic simulations

    SciTech Connect (OSTI)

    Schwen, D.; Bringa, E.; Krauser, J.; Weidinger, A.; Trautmann, C.; Hofsaess, H.

    2012-09-10

    The formation of surface hillocks in diamond-like carbon is studied experimentally and by means of large-scale molecular dynamics simulations with 5 Multiplication-Sign 10{sup 6} atoms combined with a thermal spike model. The irradiation experiments with swift heavy ions cover a large electronic stopping range between {approx}12 and 72 keV/nm. Both experiments and simulations show that beyond a stopping power threshold, the hillock height increases linearly with the electronic stopping, and agree extremely well assuming an efficiency of approximately 20% in the transfer of electronic energy to the lattice. The simulations also show a transition of sp{sup 3} to sp{sup 2} bonding along the tracks with the hillocks containing almost no sp{sup 3} contribution.

  15. Table 3. Top five retailers of electricity, with end use sectors...

    U.S. Energy Information Administration (EIA) Indexed Site

    5,"Black Diamond Power Co","Investor-owned",57388,40388,17000,0,0 " ","Total Sales, Top Five Providers",,31238820,11494224,7736888,12003726,3982 " ","Percent of Total State...

  16. Experimental Approach to Controllably Vary Protein Oxidation While Minimizing Electrode Adsorption for Boron-Doped Diamond Electrochemical Surface Mapping Applications

    SciTech Connect (OSTI)

    McClintock, Carlee; Hettich, Robert {Bob} L

    2013-01-01

    Oxidative protein surface mapping has become a powerful approach for measuring the solvent accessibility of folded protein structures. A variety of techniques exist for generating the key reagent hydroxyl radicals for these measurements; however, many of these approaches require use of radioactive sources or caustic oxidizing chemicals. The purpose of this research was to evaluate and optimize the use of boron-doped diamond (BDD) electrochemistry as a highly accessible tool for producing hydroxyl radicals as a means to induce a controllable level of oxidation on a range of intact proteins. These experiments utilize a relatively high flow rates to reduce protein residence time inside the electrochemical flow chamber, along with a unique cell activation approach to improve control over the intact protein oxidation yield. Studies were conducted to evaluate the level of protein adsorption onto the electrode surface. This report demonstrates a robust protocol for the use of BDD electrochemistry and high performance LC-MS/MS as a high-throughput experimental pipeline for probing higher order protein structure, and illustrates how it is complementary to predictive computational modeling efforts.

  17. Growth of diamond nanocrystals by pulsed laser ablation of graphite in liquid , P.W. May a,, L. Yin b

    E-Print Network [OSTI]

    Bristol, University of

    Elsevier B.V. All rights reserved. Keywords: Diamond; Pulsed laser ablation; Nanoparticles; Nanodiamond 1 materials to be created [4,5]. The conditions inside the bubbles are similar to the cavitation bubbles

  18. Systematic studies of the nucleation and growth of ultrananocrystalline diamond films on silicon substrates coated with a tungsten layer

    SciTech Connect (OSTI)

    Chu, Yueh-Chieh; Jiang, Gerald; Tu, Chia-Hao; Chang Chi; Liu, Chuan-pu; Ting, Jyh-Ming; Lee, Hsin-Li; Tzeng, Yonhua; Auciello, Orlando

    2012-06-15

    We report on effects of a tungsten layer deposited on silicon surface on the effectiveness for diamond nanoparticles to be seeded for the deposition of ultrananocrystalline diamond (UNCD). Rough tungsten surface and electrostatic forces between nanodiamond seeds and the tungsten surface layer help to improve the adhesion of nanodiamond seeds on the tungsten surface. The seeding density on tungsten coated silicon thus increases. Tungsten carbide is formed by reactions of the tungsten layer with carbon containing plasma species. It provides favorable (001) crystal planes for the nucleation of (111) crystal planes by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) in argon diluted methane plasma and further improves the density of diamond seeds/nuclei. UNCD films grown at different gas pressures on tungsten coated silicon which is pre-seeded by nanodiamond along with heteroepitaxially nucleated diamond nuclei were characterized by Raman scattering, field emission-scanning electron microscopy, and high resolution-transmission electron microscopy.

  19. Development and evaluation of operational strategies for providing an integrated diamond interchange ramp-metering control system 

    E-Print Network [OSTI]

    Tian, Zongzhong

    2004-09-30

    Diamond interchanges and their associated ramps are where the surface street arterial system and the freeway system interface. Historically, these two elements of the system have been operated with little or no coordination between the two...

  20. Black hole mimickers: Regular versus singular behavior

    SciTech Connect (OSTI)

    Lemos, Jose P. S.; Zaslavskii, Oleg B.

    2008-07-15

    Black hole mimickers are possible alternatives to black holes; they would look observationally almost like black holes but would have no horizon. The properties in the near-horizon region where gravity is strong can be quite different for both types of objects, but at infinity it could be difficult to discern black holes from their mimickers. To disentangle this possible confusion, we examine the near-horizon properties, and their connection with far away asymptotic properties, of some candidates to black mimickers. We study spherically symmetric uncharged or charged but nonextremal objects, as well as spherically symmetric charged extremal objects. Within the uncharged or charged but nonextremal black hole mimickers, we study nonextremal {epsilon}-wormholes on the threshold of the formation of an event horizon, of which a subclass are called black foils, and gravastars. Within the charged extremal black hole mimickers we study extremal {epsilon}-wormholes on the threshold of the formation of an event horizon, quasi-black holes, and wormholes on the basis of quasi-black holes from Bonnor stars. We elucidate whether or not the objects belonging to these two classes remain regular in the near-horizon limit. The requirement of full regularity, i.e., finite curvature and absence of naked behavior, up to an arbitrary neighborhood of the gravitational radius of the object enables one to rule out potential mimickers in most of the cases. A list ranking the best black hole mimickers up to the worst, both nonextremal and extremal, is as follows: wormholes on the basis of extremal black holes or on the basis of quasi-black holes, quasi-black holes, wormholes on the basis of nonextremal black holes (black foils), and gravastars. Since in observational astrophysics it is difficult to find extremal configurations (the best mimickers in the ranking), whereas nonextremal configurations are really bad mimickers, the task of distinguishing black holes from their mimickers seems to be less difficult than one could think of it.

  1. International black tea market integration and price discovery 

    E-Print Network [OSTI]

    Dharmasena, Kalu Arachchillage Senarath Dhananjaya Bandara

    2004-09-30

    In this thesis we study three basic issues related to international black tea markets: Are black tea markets integrated? Where is the price of black tea discovered? Are there leaders and followers in black tea markets? We ...

  2. Bulk emission of scalars by a rotating black hole

    E-Print Network [OSTI]

    M. Casals; S. R. Dolan; P. Kanti; E. Winstanley

    2008-07-17

    We study in detail the scalar-field Hawking radiation emitted into the bulk by a higher-dimensional, rotating black hole. We numerically compute the angular eigenvalues, and solve the radial equation of motion in order to find transmission factors. The latter are found to be enhanced by the angular momentum of the black hole, and to exhibit the well-known effect of superradiance. The corresponding power spectra for scalar fields show an enhancement with the number of dimensions, as in the non-rotating case. We compute the total mass loss rate of the black hole for a variety of black-hole angular momenta and bulk dimensions, and find that, in all cases, the bulk emission remains significantly smaller than the brane emission. The angular-momentum loss rate is also computed and found to have a smaller value in the bulk than on the brane. We present accurate bulk-to-brane emission ratios for a range of scenarios.

  3. Energy on black hole spacetimes

    E-Print Network [OSTI]

    Alejandro Corichi

    2012-07-18

    We consider the issue of defining energy for test particles on a background black hole spacetime. We revisit the different notions of energy as defined by different observers. The existence of a time-like isometry allows for the notion of a total conserved energy to be well defined, and subsequently the notion of a gravitational potential energy is also meaningful. We then consider the situation in which the test particle is adsorbed by the black hole, and analyze the energetics in detail. In particular, we show that the notion of horizon energy es defined by the isolated horizons formalism provides a satisfactory notion of energy compatible with the particle's conserved energy. As another example, we comment a recent proposal to define energy of the black hole as seen by an observer at rest. This account is intended to be pedagogical and is aimed at the level of and as a complement to the standard textbooks on the subject.

  4. Heat Engine of black holes

    E-Print Network [OSTI]

    J. Sadeghi; Kh. Jafarzade

    2015-06-23

    As we know, the cosmological constant in different theories of gravity acts as a thermodynamics variable. The cosmological constant exists in different actions of gravity and also appears in the solution of such theories. These lead to use the black hole as a heat engines. Also, there are two values for the cosmological constant as positive and negative values. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. In this paper, we are going to define heat engines for two different black holes as Dyonic BH and Kerr BH. And also, we calculate maximum efficiency for two black holes.

  5. Charged rotating dilaton black strings

    SciTech Connect (OSTI)

    Dehghani, M.H.; Farhangkhah, N.

    2005-02-15

    In this paper we, first, present a class of charged rotating solutions in four-dimensional Einstein-Maxwell-dilaton gravity with zero and Liouville-type potentials. We find that these solutions can present a black hole/string with two regular horizons, an extreme black hole or a naked singularity provided the parameters of the solutions are chosen suitable. We also compute the conserved and thermodynamic quantities, and show that they satisfy the first law of thermodynamics. Second, we obtain the (n+1)-dimensional rotating solutions in Einstein-dilaton gravity with Liouville-type potential. We find that these solutions can present black branes, naked singularities or spacetimes with cosmological horizon if one chooses the parameters of the solutions correctly. Again, we find that the thermodynamic quantities of these solutions satisfy the first law of thermodynamics.

  6. Quantum Criticality and Black Holes

    ScienceCinema (OSTI)

    Sachdev, Subir [Harvard University, Cambridge, Massachusetts, United States

    2009-09-01

    I will describe the behavior of a variety of condensed matter systems in the vicinity of zero temperature quantum phase transitions. There is a remarkable analogy between the hydrodynamics of such systems and the quantum theory of black holes. I will show how insights from this analogy have shed light on recent experiments on the cuprate high temperature superconductors. Studies of new materials and trapped ultracold atoms are yielding new quantum phases, with novel forms of quantum entanglement. Some materials are of technological importance: e.g. high temperature superconductors. Exact solutions via black hole mapping have yielded first exact results for transport coefficients in interacting many-body systems, and were valuable in determining general structure of hydrodynamics. Theory of VBS order and Nernst effect in cuprates. Tabletop 'laboratories for the entire universe': quantum mechanics of black holes, quark-gluon plasma, neutrons stars, and big-bang physics.

  7. DEVELOPMENT OF ADVANCED DRILL COMPONENTS FOR BHA USING MICROWAVE TECHNOLOGY INCORPORATING CARBIDE, DIAMOND COMPOSITES AND FUNCTIONALLY GRADED MATERIALS

    SciTech Connect (OSTI)

    Dinesh Agrawal; Rustum Roy

    2003-01-01

    The microwave processing of materials is a new emerging technology with many attractive advantages over the conventional methods. The advantages of microwave technology for various ceramic systems has already been demonstrated and proven. The recent developments at Penn State have succeeded in applying the microwave technology for the commercialization of WC/Co and diamond based cutting and drilling tools, effectively sintering of metallic materials, and fabrication of transparent ceramics for advanced applications. In recent years, the Microwave Processing and Engineering Center at Penn State University in collaboration with our industrial partner, Dennis Tool Co. has succeeded in commercializing the developed microwave technology partially funded by DOE for WC/Co and diamond based cutting and drilling tools for gas and oil exploration operations. In this program we have further developed this technology to make diamond-carbide composites and metal-carbide-diamond functionally graded materials. Several actual product of diamond-carbide composites have been processed in microwave with better performance than the conventional product. The functionally graded composites with diamond as one of the components has been for the first time successfully developed. These are the highlights of the project.

  8. Radiation transport around Kerr black holes

    E-Print Network [OSTI]

    Schnittman, Jeremy David

    2005-01-01

    This Thesis describes the basic framework of a relativistic ray-tracing code for analyzing accretion processes around Kerr black holes. We begin in Chapter 1 with a brief historical summary of the major advances in black ...

  9. Does phantom energy produce black hole?

    E-Print Network [OSTI]

    F. Rahaman; A. Ghosh; M. Kalam

    2006-12-23

    We have found an exact solution of spherically symmetrical Einstein equations describing a black hole with a special type phantom energy source. It is surprising to note that our solution is analogous to Reissner-Nordstr\\"{o}m black hole.

  10. Introduction to Black Hole Evaporation

    E-Print Network [OSTI]

    Pierre-Henry Lambert

    2014-01-16

    These lecture notes are an elementary and pedagogical introduction to the black hole evaporation, based on a lecture given by the author at the Ninth Modave Summer School in Mathematical Physics and are intended for PhD students. First, quantum field theory in curved spacetime is studied and tools needed for the remaining of the course are introduced. Then, quantum field theory in Rindler spacetime in 1+1 dimensions and in the spacetime of a spherically collapsing star are considered, leading to Unruh and Hawking effects, respectively. Finally, some consequences such as thermodynamics of black holes and information loss paradox are discussed.

  11. 4d neutral dilatonic black holes and (4+p) dimensional nondilatonic black p-branes

    E-Print Network [OSTI]

    J. R. Morris

    2000-01-11

    It is shown that, in contrast to the case of extreme 4d dilatonic black holes, 4d neutral dilatonic black holes with horizon singularities can not be interpreted as nonsingular nondilatonic black p-branes in (4+p) dimensions, regardless of the number of extra dimensions p. That is, extra dimensions do not remove naked singularities of 4d neutral dilatonic black holes.

  12. Classical and thermodynamic stability of black holes

    E-Print Network [OSTI]

    Ricardo Monteiro

    2010-06-28

    We consider the stability of black holes within both classical general relativity and the semiclassical thermodynamic description. In particular, we study linearised perturbations and their contribution to the gravitational partition function, addressing technical issues for charged (Reissner-Nordstrom) and rotating (Kerr-AdS) black holes. Exploring the connection between classical and thermodynamic stability, we find classical instabilities of Myers-Perry black holes and bifurcations to new black hole families.

  13. Will black holes eventually engulf the universe?

    E-Print Network [OSTI]

    Prado Martin-Moruno; Jose A. Jimenez Madrid; Pedro F. Gonzalez-Diaz

    2006-03-28

    The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models.

  14. Hawking Emission and Black Hole Thermodynamics

    E-Print Network [OSTI]

    Don N. Page

    2006-12-18

    A brief review of Hawking radiation and black hole thermodynamics is given, based largely upon hep-th/0409024.

  15. "Meissner effect" and Blandford-Znajek mechanism in conductive black hole magnetospheres

    E-Print Network [OSTI]

    S. S. Komissarov; J. C. McKinney

    2007-02-14

    The expulsion of axisymmetric magnetic field from the event horizons of rapidly rotating black holes has been seen as an astrophysically important effect that may significantly reduce or even nullify the efficiency of the Blandford-Znajek mechanism of powering the relativistic jets in Active Galactic Nuclei and Gamma Ray Bursts. However, this Meissner-like effect is seen in vacuum solutions of black hole electrodynamics whereas the Blandford-Znajek mechanism is concerned with plasma-filled magnetospheres. In this paper we argue that conductivity dramatically changes the properties of axisymmetric electromagnetic solutions -- even for a maximally rotating Kerr black hole the magnetic field is pulled inside the event horizon. Moreover, the conditions resulting in outgoing Poynting flux in the Blandford-Znajek mechanism exist not on the event horizon but everywhere within the black hole ergosphere. Thus, the Meissner effect is unlikely to be of interest in astrophysics of black holes, at least not in the way this has been suggested so far. These conclusions are supported by the results of time-dependent numerical simulations with three different computer codes. The test problems involve black holes with the rotation parameter ranging from $a=0.999$ to $a=1$. The pure electrodynamic simulations deal with the structure of conductive magnetospheres of black holes placed in a uniform-at-infinity magnetic field (Wald's problem) and the magnetohydrodynamic simulations are used to study the magnetospheres arising in the problem of disk accretion.

  16. FY 2005/06 Accomplishment CHP System Supplies Emergency Power at

    E-Print Network [OSTI]

    Pennycook, Steve

    ComfortTM 240 integrated combined heat and power (CHP) system at the East Hartford High School (EHHS). Technology In addition to regularly providing power, cooling, and heating to the school, the UTC Power's PureFY 2005/06 Accomplishment CHP System Supplies Emergency Power at East Hartford High School "Black

  17. Squeezars: Tidally powered stars orbiting a massive black hole

    E-Print Network [OSTI]

    Tal Alexander; Mark Morris

    2003-05-05

    We propose that there exists a class of transient sources, "squeezars", which are stars caught in highly eccentric orbits around a massive (mpowered by tidal interactions with the MBH. Their existence follows from the presence of a mass sink, the MBH, in the galactic center, which drives a flow of stars into nearly radial orbits to replace those it has destroyed. We consider two limits for the stellar response to tidal heating: surface heating with radiative cooling ("hot squeezars") and bulk heating with adiabatic expansion ("cold squeezars"), and calculate the evolution of the squeezar orbit, size, luminosity and effective temperature. The squeezar formation rate is only ~0.05 that of tidal disruption flares, but squeezar lifetimes are many orders of magnitude longer, and so future observations of squeezars in nearby galaxies can probe the tidal process that feeds MBHs and the effects of extreme tides on stars. The mean number of squeezars orbiting the Galactic MBH is estimated at 0.1-1.

  18. Black Hills Power Inc (Wyoming) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar Energy LLC JumpBiossence Jump to: navigation, searchBirahi GangaCoral

  19. Black Hills Power - Commercial Energy Efficiency Programs | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De pEnergy Industrial Local Government Nonprofit State

  20. Black Hills Power - Residential Customer Rebate Program | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De pEnergy Industrial Local Government Nonprofit

  1. Black Hills Power - Residential Customer Rebate Program | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De pEnergy Industrial Local Government NonprofitEnergy

  2. Black Hills Power - Residential Customer Rebate Program | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De pEnergy Industrial Local Government

  3. Black Hills Power - Commercial Energy Efficiency Programs | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann JacksonDepartment|Marketing, LLC |Energy AdvisorEnergy 4Prepared Remarks

  4. Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole

    E-Print Network [OSTI]

    Macedo, Caio F B; Crispino, Luís C B

    2015-01-01

    Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black hole. Some regular black hole solutions were found in the context of non-linear electrodynamics, the Bardeen black hole being the first one proposed. In this paper, we consider a planar massless scalar wave scattered by a Bardeen black hole. We compare the scattering cross section computed using a partial-wave description with the classical geodesic scattering of a stream of null geodesics, as well as with the semi-classical glory approximation. We obtain that, for some values of the corresponding black hole charge, the scattering cross section of a Bardeen black hole has a similar interference pattern of a Reissner-Nordstr\\"om black hole.

  5. Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole

    E-Print Network [OSTI]

    Caio F. B. Macedo; Ednilton S. de Oliveira; Luís C. B. Crispino

    2015-06-26

    Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black hole. Some regular black hole solutions were found in the context of non-linear electrodynamics, the Bardeen black hole being the first one proposed. In this paper, we consider a planar massless scalar wave scattered by a Bardeen black hole. We compare the scattering cross section computed using a partial-wave description with the classical geodesic scattering of a stream of null geodesics, as well as with the semi-classical glory approximation. We obtain that, for some values of the corresponding black hole charge, the scattering cross section of a Bardeen black hole has a similar interference pattern of a Reissner-Nordstr\\"om black hole.

  6. New approaches to black holes Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    References Eric Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 2 / 36 Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 3 / 36 #12;Local (2006)] Eric Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 4

  7. Perovskite Power

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

    Perovskite Power 1663 Los Alamos science and technology magazine Latest Issue:October 2015 past issues All Issues submit Perovskite Power A breakthrough in the production of...

  8. Nucleation of diamond by pure carbon ion bombardment--a transmission electron microscopy study

    SciTech Connect (OSTI)

    Yao, Y.; Liao, M.Y.; Wang, Z.G.; Lifshitz, Y.; Lee, S.

    2005-08-08

    A cross-sectional high-resolution transmission electron microscopy (HRTEM) study of a film deposited by a 1 keV mass-selected carbon ion beam onto silicon held at 800 deg. C is presented. Initially, a graphitic film with its basal planes perpendicular to the substrate is evolving. The precipitation of nanodiamond crystallites in upper layers is confirmed by HRTEM, selected area electron diffraction, and electron energy loss spectroscopy. The nucleation of diamond on graphitic edges as predicted by Lambrecht et al. [W. R. L. Lambrecht, C. H. Lee, B. Segall, J. C. Angus, Z. Li, and M. Sunkara, Nature, 364 607 (1993)] is experimentally confirmed. The results are discussed in terms of our recent subplantation-based diamond nucleation model.

  9. Low-temperature electrical transport in B-doped ultrananocrystalline diamond film

    SciTech Connect (OSTI)

    Li, Lin; Zhao, Jing; Hu, Zhaosheng; Quan, Baogang; Li, Junjie Gu, Changzhi

    2014-05-05

    B-doped ultrananocrystalline diamond (UNCD) films are grown using hot-filament chemical vapor deposition method, and their electrical transport properties varying with temperature are investigated. When the B-doped concentration of UNCD film is low, a step-like increase feature of the resistance is observed with decreasing temperature, reflecting at least three temperature-modified electronic state densities at the Fermi level according to three-dimensional Mott's variable range hopping transport mechanism, which is very different from that of reported B-doped nanodiamond. With increasing B-doped concentration, a superconductive transformation occurs in the UNCD film and the highest transformation temperature of 5.3?K is observed, which is higher than that reported for superconducting nanodiamond films. In addition, the superconducting coherence length is about 0.63?nm, which breaks a reported theoretical and experimental prediction about ultra-nanoscale diamond's superconductivity.

  10. Performance of a beam-multiplexing diamond crystal monochromator at the Linac Coherent Light Source

    SciTech Connect (OSTI)

    Zhu, Diling, E-mail: dlzhu@slac.stanford.edu; Feng, Yiping; Lemke, Henrik T.; Fritz, David M.; Chollet, Matthieu; Glownia, J. M.; Alonso-Mori, Roberto; Sikorski, Marcin; Song, Sanghoon; Williams, Garth J.; Messerschmidt, Marc; Boutet, Sébastien; Robert, Aymeric [Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Stoupin, Stanislav; Shvyd'ko, Yuri V. [Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439 (United States); Terentyev, Sergey A.; Blank, Vladimir D. [Technological Institute of Superhard and Novel Carbon Materials, Tsentralnaya str. 7a, Troitsk, Moscow 142190 (Russian Federation); Driel, Tim B. van [Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Center for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby (Denmark)

    2014-06-15

    A double-crystal diamond monochromator was recently implemented at the Linac Coherent Light Source. It enables splitting pulses generated by the free electron laser in the hard x-ray regime and thus allows the simultaneous operations of two instruments. Both monochromator crystals are High-Pressure High-Temperature grown type-IIa diamond crystal plates with the (111) orientation. The first crystal has a thickness of ?100 ?m to allow high reflectivity within the Bragg bandwidth and good transmission for the other wavelengths for downstream use. The second crystal is about 300 ?m thick and makes the exit beam of the monochromator parallel to the incoming beam with an offset of 600 mm. Here we present details on the monochromator design and its performance.

  11. Design and manufacture of micro-optical arrays using 3D diamond machining techniques

    E-Print Network [OSTI]

    Juergen Schmoll; David J. Robertson; David A. Ryder

    2006-06-07

    We describe our work towards the manufacture of micro-optical arrays using freeform diamond machining techniques. Simulations have been done to show the feasibility of manufacturing micro-lens arrays using the slow-tool servo method. Using this technique, master shapes can be produced for replication of micro-lens arrays of either epoxy-on-glass or monolthic glass types. A machine tool path programme has been developed on the machine software platform DIFFSYS, allowing the production of spherical, aspherical and toric arrays. In addition, in theory spatially varying lenslets, sparse arrays and dithered lenslet arrays (for high contrast applications) are possible to produce. In practice, due to the diamond tool limitations not all formats are feasible. Investigations into solving this problem have been carried out and a solution is presented here.

  12. Efficient graphite ring heater suitable for diamond-anvil cells to 1300 K

    SciTech Connect (OSTI)

    Du Zhixue; Amulele, George; Lee, Kanani K. M.; Miyagi, Lowell

    2013-02-15

    In order to generate homogeneous high temperatures at high pressures, a ring-shaped graphite heater has been developed to resistively heat diamond-anvil cell (DAC) samples up to 1300 K. By putting the heater in direct contact with the diamond anvils, this graphite heater design features the following advantages: (1) efficient heating: sample can be heated to 1300 K while the DAC body temperature remains less than 800 K, eliminating the requirement of a special alloy for the DAC; (2) compact design: the sample can be analyzed with in situ measurements, e.g., x-ray, optical, and electrical probes are possible. In particular, the side access of the heater allows for radial x-ray diffraction (XRD) measurements in addition to traditional axial XRD.

  13. Diamond pixel detector for beam profile monitoring in COMET experiment at J-PARC

    E-Print Network [OSTI]

    M. Cerv; P. Sarin; H. Pernegger; P. Vageesvaran; E. Griesmayer

    2014-11-15

    We present the design and initial prototype results of a pixellized proton beam profile monitor for the COMET experiment at J-PARC. The goal of COMET is to look for charged lepton flavor violation by direct muon to electron conversion at a sensitivity of $0^{-19}$. An 8 GeV proton beam pulsed at 100 ns with $10^{10}$ protons/s will be used to create muons through pion production and decay. In the final experiment, the proton flux will be raised to $10^{14}$ protons/sec to increase the sensitivity. These requirements of harsh radiation tolerance and fast readout make diamond a good choice for constructing a beam profile monitor in COMET. We present first results of the characterization of single crystal diamond (scCVD) sourced from a new company, 2a systems Singapore. Our measurements indicate excellent charge collection efficiency and high carrier mobility down to cryogenic temperatures.

  14. Causal extraction of black hole rotational energy by various kinds of electromagnetic fields

    SciTech Connect (OSTI)

    Koide, Shinji; Baba, Tamon

    2014-09-10

    Recent general relativistic magnetohydrodynamics (MHD) simulations have suggested that relativistic jets from active galactic nuclei (AGNs) have been powered by the rotational energy of central black holes. Some mechanisms for extraction of black hole rotational energy have been proposed, like the Penrose process, Blandford-Znajek mechanism, MHD Penrose process, and superradiance. The Blandford-Znajek mechanism is the most promising mechanism for the engines of the relativistic jets from AGNs. However, an intuitive interpretation of this mechanism with causality is not yet clarified, while the Penrose process has a clear interpretation for causal energy extraction from a black hole with negative energy. In this paper, we present a formula to build physical intuition so that in the Blandford-Znajek mechanism, as well as in other electromagnetic processes, negative electromagnetic energy plays an important role in causal extraction of the rotational energy of black holes.

  15. Laser generation and detection of longitudinal and shear acoustic waves in a diamond anvil cell

    SciTech Connect (OSTI)

    Chigarev, Nikolay; Zinin, Pavel; Ming Lichung; Amulele, George; Bulou, Alain; Gusev, Vitalyi

    2008-11-03

    Laser ultrasonics in a point-source-point-receiver configuration is applied for the evaluation of elastic properties of nontransparent materials in a diamond anvil cell at high pressures. Measurement of both longitudinal and shear acoustic wave velocities in an iron foil at pressures up to 23 GPa does not require any information in addition to the one obtained by all-optical pump-probe technique.

  16. The Ramsey number of diamond-matchings and loose cycles in hypergraphs

    E-Print Network [OSTI]

    Sarkozy, Gabor

    The Ramsey number of diamond-matchings and loose cycles in hypergraphs Andr´as Gy´arf´as Computer Abstract The 2-color Ramsey number R(C3 n, C3 n) of a 3-uniform loose cycle Cn is asymp- totic to 5n/4 extend their result to the r-uniform case by show- ing that the corresponding Ramsey number is asymptotic

  17. US Synthetic Corp (TRL 4 Component)- The Development of Open, Water Lubricated Polycrystalline Diamond Thrust Bearings for use in Marine Hydrokinetic (MHK) Energy Machines

    Broader source: Energy.gov [DOE]

    US Synthetic Corp (TRL 4 Component) - The Development of Open, Water Lubricated Polycrystalline Diamond Thrust Bearings for use in Marine Hydrokinetic (MHK) Energy Machines

  18. From Pinholes to Black Holes

    SciTech Connect (OSTI)

    Fenimore, Edward E.

    2014-10-06

    Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  19. Proton recoil telescope based on diamond detectors for measurement of fusion neutrons

    E-Print Network [OSTI]

    B. Caiffi; M. Osipenko; M. Ripani; M. Pillon; M. Taiuti

    2015-05-23

    Diamonds are very promising candidates for the neutron diagnostics in harsh environments such as fusion reactor. In the first place this is because of their radiation hardness, exceeding that of Silicon by an order of magnitude. Also, in comparison to the standard on-line neutron diagnostics (fission chambers, silicon based detectors, scintillators), diamonds are less sensitive to $\\gamma$ rays, which represent a huge background in fusion devices. Finally, their low leakage current at high temperature suppresses the detector intrinsic noise. In this talk a CVD diamond based detector has been proposed for the measurement of the 14 MeV neutrons from D-T fusion reaction. The detector was arranged in a proton recoil telescope configuration, featuring a plastic converter in front of the sensitive volume in order to induce the (n,p) reaction. The segmentation of the sensitive volume, achieved by using two crystals, allowed to perform measurements in coincidence, which suppressed the neutron elastic scattering background. A preliminary prototype was assembled and tested at FNG (Frascati Neutron Generator, ENEA), showing promising results regarding efficiency and energy resolution.

  20. Local and bulk 13C hyperpolarization in NV-centered diamonds at variable fields and orientations

    E-Print Network [OSTI]

    Gonzalo A. Alvarez; Christian O. Bretschneider; Ran Fischer; Paz London; Hisao Kanda; Shinobu Onoda; Junichi Isoya; David Gershoni; Lucio Frydman

    2014-12-30

    Polarizing nuclear spins is of fundamental importance in biology, chemistry and physics. Methods for hyperpolarizing 13C nuclei from free electrons in bulk, usually demand operation at cryogenic temperatures. Room-temperature approaches targeting diamonds with nitrogen-vacancy (NV) centers could alleviate this need, but hitherto proposed strategies lack generality as they demand stringent conditions on the strength and/or alignment of the magnetic field. We report here an approach for achieving efficient electron->13C spin alignment transfers, compatible with a broad range of magnetic field strengths and field orientations with respect to the diamond crystal. This versatility results from combining coherent microwave- and incoherent laser-induced transitions between selected energy states of the coupled electron-nuclear spin manifold. 13C-detected Nuclear Magnetic Resonance (NMR) experiments demonstrate that this hyperpolarization can be transferred via first-shell or via distant 13Cs, throughout the nuclear bulk ensemble. This method opens new perspectives for applications of diamond NV centers in NMR, and in quantum information processing.

  1. Black Holes in Galaxy Mergers: Evolution of Quasars

    E-Print Network [OSTI]

    Philip F. Hopkins; Lars Hernquist; Thomas J. Cox; Tiziana Di Matteo; Paul Martini; Brant Robertson; Volker Springel

    2005-06-13

    Based on numerical simulations of gas-rich galaxy mergers, we discuss a model in which quasar activity is tied to the self-regulated growth of supermassive black holes in galaxies. Nuclear inflow of gas attending a galaxy collision triggers a starburst and feeds black hole growth, but for most of the duration of the starburst, the black hole is heavily obscured by surrounding gas and dust which limits the visibility of the quasar, especially at optical and UV wavelengths. Eventually, feedback energy from accretion heats the gas and expels it in a powerful wind, leaving a 'dead quasar'. Between buried and dead phases there is a window during which the galaxy would be seen as a luminous quasar. Because the black hole mass, radiative output, and distribution of obscuring gas and dust all evolve strongly with time, the duration of this phase of observable quasar activity depends on both the waveband and imposed luminosity threshold. We determine the observed and intrinsic lifetimes as a function of luminosity and frequency, and calculate observable lifetimes ~10 Myr for bright quasars in the optical B-band, in good agreement with empirical estimates and much smaller than the black hole growth timescales ~100 Myr, naturally producing a substantial population of 'buried' quasars. However, observed and intrinsic energy outputs converge in the IR and hard X-ray bands as attenuation becomes weaker and chances of observation greatly increase. We obtain the distribution of column densities along sightlines in which the quasar is seen above a given luminosity, and find that our result agrees remarkably well with observed estimates of the column density distribution from the SDSS for appropriate luminosity thresholds. (Abridged)

  2. Extremal Higher Spin Black Holes

    E-Print Network [OSTI]

    Máximo Bañados; Alejandra Castro; Alberto Faraggi; Juan I. Jottar

    2015-11-30

    The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal ensemble. Building on these ideas, we discuss a definition of black hole extremality which is appropriate to the topological character of 3d higher spin theories. Our definition can be phrased in terms of the Jordan class of the holonomy around a non-contractible (angular) cycle, and we show that it is compatible with the zero-temperature limit of smooth black hole solutions. While this notion of extremality does not require nor implies the existence of supersymmetry, we exemplify its consequences in the context of sl(3|2) + sl(3|2) Chern-Simons theory. Remarkably, while as usual not all extremal solutions preserve supersymmetries, we find that the higher spin setup allows for non-extremal supersymmetric black hole solutions as well. Furthermore, we discuss our results from the perspective of the holographic duality between sl(3|2) + sl(3|2) Chern-Simons theory and two-dimensional CFTs with W_{(3|2)} symmetry, the simplest higher spin extension of the N=2 super-Virasoro algebra. In particular, we compute W_{(3|2)} BPS bounds at the full quantum level, and relate their semiclassical limit to extremal black hole or conical defect solutions in the 3d bulk. Along the way, we discuss the role of the spectral flow automorphism and provide a conjecture for the form of the semiclassical BPS bounds in general N=2 two-dimensional CFTs with extended symmetry algebras.

  3. Black hole microstates in AdS

    E-Print Network [OSTI]

    Shaghoulian, Edgar

    2015-01-01

    We extend a recently derived higher-dimensional Cardy formula to include angular momenta, which we use to obtain the Bekensten-Hawking entropy of AdS black branes, compactified rotating branes, and large Schwarzschild/Kerr black holes. This is the natural generalization of Strominger's microscopic derivation of the BTZ black hole entropy to higher dimensions. We propose an extension to include $U(1)$ charge, which agrees with the Bekenstein-Hawking entropy of large Reissner-Nordstrom/Kerr-Newman black holes at high temperature. We extend the results to arbitrary hyperscaling violation exponent (this captures the case of black D$p$-branes as a subclass) and reproduce logarithmic corrections.

  4. Direct observation of electron emission from the grain boundaries of chemical vapour deposition diamond films by tunneling atomic force microscopy

    SciTech Connect (OSTI)

    Chatterjee, Vijay; Harniman, Robert; May, Paul W.; Barhai, P. K.

    2014-04-28

    The emission of electrons from diamond in vacuum occurs readily as a result of the negative electron affinity of the hydrogenated surface due to features with nanoscale dimensions, which can concentrate electric fields high enough to induce electron emission from them. Electrons can be emitted as a result of an applied electric field (field emission) with possible uses in displays or cold-cathode devices. Alternatively, electrons can be emitted simply by heating the diamond in vacuum to temperatures as low as 350?°C (thermionic emission), and this may find applications in solar energy generation or energy harvesting devices. Electron emission studies usually use doped polycrystalline diamond films deposited onto Si or metallic substrates by chemical vapor deposition, and these films have a rough, faceted morphology on the micron or nanometer scale. Electron emission is often improved by patterning the diamond surface into sharp points or needles, the idea being that the field lines concentrate at the points lowering the barrier for electron emission. However, there is little direct evidence that electrons are emitted from these sharp tips. The few reports in the literature that have studied the emission sites suggested that emission came from the grain boundaries and not the protruding regions. We now present direct observation of the emission sites over a large area of polycrystalline diamond using tunneling atomic force microscopy. We confirm that the emission current comes mostly from the grain boundaries, which is consistent with a model for emission in which the non-diamond phase is the source of electrons with a threshold that is determined by the surrounding hydrogenated diamond surface.

  5. Diamond RF Switch for Enhanced Communications - Energy Innovation Portal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeeting |DesignCommunitiesYu &DiagnosisTheAdvanced

  6. Robust Diamond-Based RF Switch Yields Enhanced Communication Capabilities |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100NationalquestionnairesDrought-inducedPhotoRoboRAVERobotics

  7. Diamond Willow Wind (07) Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower VenturesInformation9)ask queries TypeDeveloper|Winds Wind7) Wind

  8. Diamond Willow Wind (08) Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower VenturesInformation9)ask queries TypeDeveloper|Winds Wind7) Wind8)

  9. USES OF HYPERTHERMAL ATOMIC BEAM FOR LOW TEMPERATURE DIAMOND GROWTH |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With WIPPfinal design andBiofuels for Military andPrinceton Plasma

  10. Electric power from offshore wind via synoptic-scale interconnection

    E-Print Network [OSTI]

    Firestone, Jeremy

    Electric power from offshore wind via synoptic-scale interconnection Willett Kemptona,1 , Felipe M regional estimate, Kempton et al. (2) calculated that two-thirds of the offshore wind power off the U in the U.S. Atlantic region is already underway. Fig. 1 shows as black squares offshore wind developments

  11. Radio Jets in Galaxies with Actively Accreting Black Holes: new insights from the SDSS

    E-Print Network [OSTI]

    Guinevere Kauffmann; Timothy M. Heckman; Philip N. Best

    2007-09-19

    The majority of nearby radio-loud AGN are found in massive, old elliptical galaxies with weak emission lines. At high redshifts,however, most known radio AGN have strong emission lines. In this paper, we examine a subset of radio AGN with emission lines selected from the Sloan Digital Sky Survey. The probability for a nearby radio AGN to have emission lines is a strongly decreasing function of galaxy mass and an increasing function of radio luminosity above 10^25 W/Hz. Emission line and radio luminosities are correlated, but with large dispersion. At a given radio power, AGN with small black holes have higher [OIII] luminosities (which we interpret as higher accretion rates) than AGN with big black holes. However, if we scale both radio and emission line luminosities by the black hole mass, we find a correlation between normalized radio power and accretion rate in Eddington units that is independent of black hole mass. There is also a clear correlation between normalized radio power and the age of the stellar population in the galaxy. Present-day AGN with the highest normalized radio powers are confined to galaxies with small black holes. High-redshift, high radio-luminosity AGN could be explained if big black holes were similarly active at earlier cosmic epochs. To investigate why only a small fraction of emission line AGN become radio loud, we create matched samples of radio-loud and radio-quiet AGN and compare their host galaxy properties and environments. The main difference lies in their environments; our local density estimates are a factor 2 larger around the radio-loud AGN. We propose a scenario in which radio-loud AGN with emission lines are located in galaxies where accretion of both cold and hot gas can occur simultaneously. (Abridged)

  12. An Intermediate-Mass Black Hole Candidate in M51?

    E-Print Network [OSTI]

    Earnshaw, H M

    2015-01-01

    We present the current results of an investigation into M51 ULX-7, using archival data from XMM-Newton, Chandra and NuSTAR, and optical and radio data from HST and VLA. The source has a consistently hard power-law X-ray spectrum and high short-term variability. This is unusual variability behaviour for a ULX, as we would expect highly variable ULXs to have soft energy spectra. The power spectrum features a break at ~1e-3 Hz, from low frequency spectral index alpha=0.1 to high frequency spectral index alpha=0.8, analogous to the low frequency break found in power spectra of black holes accreting in the low/hard state. We do not observe a corresponding high frequency break, however taking the white noise level as a frequency lower limit of the break, we can calculate a black hole mass upper limit of 9.12e4 solar masses, assuming that the ULX is in the low/hard state. While there is no radio detection, we find a flux density upper limit of 87 micro-Jy/beam. Using the X-ray/radio fundamental plane, we calculate a...

  13. Black Hole Thermodynamics and Electromagnetism

    E-Print Network [OSTI]

    Burra G. Sidharth

    2005-07-15

    We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

  14. Quantum chaos inside Black Holes

    E-Print Network [OSTI]

    Addazi, Andrea

    2015-01-01

    We show how semiclassical black holes can be reinterpreted as an effective geometry, composed of a large ensamble of horizonless naked singularities (eventually smoothed at the Planck scale). We call this new items {\\it frizzyballs}, which can be rigorously defined by euclidean path integral approach. This has interesting implications regarding information paradoxes. We demonstrate that infalling information will chaotically propagate inside this system before going to the full quantum gravity regime (Planck scale).

  15. Quantum chaos inside Black Holes

    E-Print Network [OSTI]

    Andrea Addazi

    2015-08-30

    We show how semiclassical black holes can be reinterpreted as an effective geometry, composed of a large ensamble of horizonless naked singularities (eventually smoothed at the Planck scale). We call this new items {\\it frizzyballs}, which can be rigorously defined by euclidean path integral approach. This has interesting implications regarding information paradoxes. We demonstrate that infalling information will chaotically propagate inside this system before going to the full quantum gravity regime (Planck scale).

  16. Classical Black Holes Are Hot

    E-Print Network [OSTI]

    Erik Curiel

    2014-11-09

    In the early 1970s it is was realized that there is a striking formal analogy between the Laws of black-hole mechanics and the Laws of classical thermodynamics. Before the discovery of Hawking radiation, however, it was generally thought that the analogy was only formal, and did not reflect a deep connection between gravitational and thermodynamical phenomena. It is still commonly held that the surface gravity of a stationary black hole can be construed as a true physical temperature and its area as a true entropy only when quantum effects are taken into account; in the context of classical general relativity alone, one cannot cogently construe them so. Does the use of quantum field theory in curved spacetime offer the only hope for taking the analogy seriously? I think the answer is `no'. To attempt to justify that answer, I shall begin by arguing that the standard argument to the contrary is not physically well founded, and in any event begs the question. Looking at the various ways that the ideas of "temperature" and "entropy" enter classical thermodynamics then will suggest arguments that, I claim, show the analogy between classical black-hole mechanics and classical thermodynamics should be taken more seriously, without the need to rely on or invoke quantum mechanics. In particular, I construct an analogue of a Carnot cycle in which a black hole "couples" with an ordinary thermodynamical system in such a way that its surface gravity plays the role of temperature and its area that of entropy. Thus, the connection between classical general relativity and classical thermodynamics on their own is already deep and physically significant, independent of quantum mechanics.

  17. The scattering matrix approach for the quantum black hole, an overview

    E-Print Network [OSTI]

    G. 't Hooft

    1996-07-09

    If one assumes the validity of conventional quantum field theory in the vicinity of the horizon of a black hole, one does not find a quantum mechanical description of the entire black hole that even remotely resembles that of conventional forms of matter; in contrast with matter made out of ordinary particles one finds that, even if embedded in a finite volume, a black hole would be predicted to have a strictly continuous spectrum. Dissatisfied with such a result, which indeed hinges on assumptions concerning the horizon that may well be wrong, various investigators have now tried to formulate alternative approaches to the problem of ``quantizing" the black hole. We here review the approach based on the assumption of quantum mechanical purity and unitarity as a starting point, as has been advocated by the present author for some time, concentrating on the physics of the states that should live on a black hole horizon. The approach is shown to be powerful in not only producing promising models for the quantum black hole, but also new insights concerning the dynamics of physical degrees of freedom in ordinary flat space-time.

  18. Dynamics of Scalar Fields in the Background of Rotating Black Holes

    E-Print Network [OSTI]

    W. Krivan; P. Laguna; P. Papadopoulos

    1996-06-04

    A numerical study of the evolution of a massless scalar field in the background of rotating black holes is presented. First, solutions to the wave equation are obtained for slowly rotating black holes. In this approximation, the background geometry is treated as a perturbed Schwarzschild spacetime with the angular momentum per unit mass playing the role of a perturbative parameter. To first order in the angular momentum of the black hole, the scalar wave equation yields two coupled one-dimensional evolution equations for a function representing the scalar field in the Schwarzschild background and a second field that accounts for the rotation. Solutions to the wave equation are also obtained for rapidly rotating black holes. In this case, the wave equation does not admit complete separation of variables and yields a two-dimensional evolution equation. The study shows that, for rotating black holes, the late time dynamics of a massless scalar field exhibit the same power-law behavior as in the case of a Schwarzschild background independently of the angular momentum of the black hole.

  19. Energy Distribution for Non-commutative Radiating Schwarzschild Black Holes

    E-Print Network [OSTI]

    I. Radinschi; F. Rahaman; U. F. Mondal

    2012-07-22

    The aim of this article is the calculation of the energy-momentum for a non-commutative radiating Schwarzschild black hole in order to obtain the expressions for energy. We make the calculations with the Einstein and M\\oller prescriptions. We show that the expressions for energy in both the prescriptions depend on the mass $M$, $\\theta$ parameter and radial coordinate. We make some comparisons between the results. Our results show that the Einstein prescription is a more powerful concept than the M\\oller prescription.

  20. Sandia Energy - Black Engineer of the Year Award

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-Throughput Analysis ofSample SULI ProgramPhysical SocietylasersPondBiomassBlack

  1. Power supply

    DOE Patents [OSTI]

    Yakymyshyn, Christopher Paul (Seminole, FL); Hamilton, Pamela Jane (Seminole, FL); Brubaker, Michael Allen (Loveland, CO)

    2007-12-04

    A modular, low weight impedance dropping power supply with battery backup is disclosed that can be connected to a high voltage AC source and provide electrical power at a lower voltage. The design can be scaled over a wide range of input voltages and over a wide range of output voltages and delivered power.

  2. Relationship of Black Holes to Bulges

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese

    2001-07-08

    Supermassive black holes appear to be uniquely associated with galactic bulges. The mean ratio of black hole mass to bulge mass was until recently very uncertain, with ground based, stellar kinematical data giving a value roughly an order of magnitude larger than other techniques. The discrepancy was resolved with the discovery of the M-sigma relation, which simultaneously established a tight corrrelation between black hole mass and bulge velocity dispersion, and confirmed that the stellar kinematical mass estimates were systematically too large due to failure to resolve the black hole's sphere of influence. There is now excellent agreement between the various techniques for estimating the mean black hole mass, including dynamical mass estimation in quiescent galaxies; reverberation mapping in active galaxies and quasars; and computation of the mean density of compact objects based on integrated quasar light. Implications of the M-sigma relation for the formation of black holes are discussed.

  3. Design of microcavities in diamond-based photonic crystals by Fourier- and real-space analysis of cavity fields

    E-Print Network [OSTI]

    Janine Riedrich-Möller; Elke Neu; Christoph Becher

    2010-01-04

    We present the design of two-dimensional photonic crystal microcavities in thin diamond membranes well suited for coupling of color centers in diamond. By comparing simulated and ideal field distributions in Fourier and real space and by according modification of air hole positions and size, we optimize the cavity structure yielding high quality factors up to Q = 320000 with a modal volume of V = 0.35 (lambda/n)^3. Using the very same approach we also improve previous designs of a small modal volume microcavity in silicon, gaining a factor of 3 in cavity Q. In view of practical realization of photonic crystals in synthetic diamond films, it is necessary to investigate the influence of material absorption on the quality factor. We show that this influence can be predicted by a simple model, replacing time consuming simulations.

  4. Boson shells harboring charged black holes

    SciTech Connect (OSTI)

    Kleihaus, Burkhard; Kunz, Jutta; Laemmerzahl, Claus; List, Meike

    2010-11-15

    We consider boson shells in scalar electrodynamics coupled to Einstein gravity. The interior of the shells can be empty space, or harbor a black hole or a naked singularity. We analyze the properties of these types of solutions and determine their domains of existence. We investigate the energy conditions and present mass formulae for the composite black hole-boson shell systems. We demonstrate that these types of solutions violate black hole uniqueness.

  5. Thermodynamic fluctuation in black string flow

    E-Print Network [OSTI]

    Meng Sun; Yong-Chang Huna

    2015-06-14

    It has long been noticed that Laudau-Lifshitz theory can be used to study the fluctuation of a system that contains a black hole. Since the black string can be constructed by extending n-dimensional black hole into one extra dimension. We study the fluctuation of black string flow with a Schwarzschlid-like metric in D=n+1 dimensional spacetime and a charged solution in D=5 dimensional spacetime and get the second moments of the fluctuation of the mass flux and charge flux.

  6. Thermodynamic fluctuation in black string flow

    E-Print Network [OSTI]

    Meng Sun; Yong-Chang Huang

    2015-05-11

    It has long been noticed that Laudau-Lifshitz theory can be used to study the fluctuation of a system that contains a black hole. Since the black string can be constructed by extending n-dimensional black hole into one extra dimension. We study the fluctuation of black string flow with a Schwarzschlid-like metric in D=n+1 dimensional spacetime and a charged solution in D=5 dimensional spacetime and get the second moments of the fluctuation of the mass flux and charge flux.

  7. Black carbon contribution to global warming

    SciTech Connect (OSTI)

    Chylek, P.; Johnson, B.; Kou, L.; Wong, J.

    1996-12-31

    Before the onset of industrial revolution the only important source of black carbon in the atmosphere was biomass burning. Today, black carbon production is divided between the biomass and fossil fuel burning. Black carbon is a major agent responsible for absorption of solar radiation by atmospheric aerosols. Thus black carbon makes other aerosols less efficient in their role of reflecting solar radiation and cooling the earth-atmosphere system. Black carbon also contributes to the absorption of solar radiation by clouds and snow cover. The authors present the results of black carbon concentrations measurements in the atmosphere, in cloud water, in rain and snow melt water collected during the 1992--1996 time period over the southern Nova Scotia. Their results are put into the global and historical perspective by comparing them with the compilation of past measurements at diverse locations and with their measurements of black carbon concentrations in the Greenland and Antarctic ice cores. Black carbon contribution to the global warming is estimated, and compared to the carbon dioxide warming, using the radiative forcing caused by the black carbon at the top of the atmosphere.

  8. Lower Dimensional Black Holes: Inside and Out

    E-Print Network [OSTI]

    R. B. Mann

    1995-01-27

    I survey the physics of black holes in two and three spacetime dimensions, with special attention given to an understanding of their exterior and interior properties.

  9. Black Holes: from Speculations to Observations

    E-Print Network [OSTI]

    Thomas W. Baumgarte

    2006-04-13

    This paper provides a brief review of the history of our understanding and knowledge of black holes. Starting with early speculations on ``dark stars'' I discuss the Schwarzschild "black hole" solution to Einstein's field equations and the development of its interpretation from "physically meaningless" to describing the perhaps most exotic and yet "most perfect" macroscopic object in the universe. I describe different astrophysical black hole populations and discuss some of their observational evidence. Finally I close by speculating about future observations of black holes with the new generation of gravitational wave detectors.

  10. Rotating Black Holes and Coriolis Effect

    E-Print Network [OSTI]

    Wu, Xiaoning; Yuan, Pei-Hung; Cho, Chia-Jui

    2015-01-01

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  11. Rotating Black Holes and Coriolis Effect

    E-Print Network [OSTI]

    Xiaoning Wu; Yi Yang; Pei-Hung Yuan; Chia-Jui Cho

    2015-11-27

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  12. Nanoimplantation and Purcell enhancement of single NV centers in photonic crystal cavities in diamond

    E-Print Network [OSTI]

    Janine Riedrich-Möller; Sébastien Pezzagna; Jan Meijer; Christoph Pauly; Frank Mücklich; Matthew Markham; Andrew M. Edmonds; Christoph Becher

    2015-03-19

    We present the controlled creation of single nitrogen-vacancy (NV) centers via ion implantation at the center of a photonic crystal cavity which is fabricated in an ultrapure, single crystal diamond membrane. High-resolution placement of NV centers is achieved using collimation of a 5keV-nitrogen ion beam through a pierced tip of an atomic force microscope (AFM). We demonstrate coupling of the implanted NV centers' broad band fluorescence to a cavity mode and observe Purcell enhancement of the spontaneous emission. The results are in good agreement with a master equation model for the cavity coupling.

  13. Pretreatment process for forming a smooth surface diamond film on a carbon-coated substrate

    DOE Patents [OSTI]

    Feng, Z.; Brewer, M.; Brown, I.; Komvopoulos, K.

    1994-05-03

    A process is disclosed for the pretreatment of a carbon-coated substrate to provide a uniform high density of nucleation sites thereon for the subsequent deposition of a continuous diamond film without the application of a bias voltage to the substrate. The process comprises exposing the carbon-coated substrate, in a microwave plasma enhanced chemical vapor deposition system, to a mixture of hydrogen-methane gases, having a methane gas concentration of at least about 4% (as measured by partial pressure), while maintaining the substrate at a pressure of about 10 to about 30 Torr during the pretreatment. 6 figures.

  14. Fabrication of triangular nanobeam waveguide networks in bulk diamond using single-crystal silicon hard masks

    SciTech Connect (OSTI)

    Bayn, I.; Mouradian, S.; Li, L.; Goldstein, J. A.; Schröder, T.; Zheng, J.; Chen, E. H.; Gaathon, O.; Englund, Dirk; Lu, M.; Stein, A.; Ruggiero, C. A.; Salzman, J.; Kalish, R.

    2014-11-24

    A scalable approach for integrated photonic networks in single-crystal diamond using triangular etching of bulk samples is presented. We describe designs of high quality factor (Q?=?2.51?×?10{sup 6}) photonic crystal cavities with low mode volume (V{sub m}?=?1.062?×?(?/n){sup 3}), which are connected via waveguides supported by suspension structures with predicted transmission loss of only 0.05?dB. We demonstrate the fabrication of these structures using transferred single-crystal silicon hard masks and angular dry etching, yielding photonic crystal cavities in the visible spectrum with measured quality factors in excess of Q?=?3?×?10{sup 3}.

  15. Chip-Scale Nanofabrication of Single Spins and Spin Arrays in Diamond

    SciTech Connect (OSTI)

    Toyli, David M.; Weis, Christoph D.; Fuchs, D.; Schenkel, Thomas; Awschalom, David D.

    2010-07-02

    We demonstrate a technique to nanofabricate nitrogen vacancy (NV) centers in diamond based on broad-beam nitrogen implantation through apertures in electron beam lithography resist. This method enables high-throughput nanofabrication of single NV centers on sub-100-nm length scales. Secondary ion mass spectroscopy measurements facilitate depth profiling of the implanted nitrogen to provide three-dimensional characterization of the NV center spatial distribution. Measurements of NV center coherence with on-chip coplanar waveguides suggest a pathway for incorporating this scalable nanofabrication technique in future quantum applications.

  16. Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)

    SciTech Connect (OSTI)

    Sideras-Haddad, E.; Schenkel, T.; Shrivastava, S.; Makgato, T.; Batra, A.; Weis, C. D.; Persaud, A.; Erasmus, R.; Mwakikunga, B.

    2009-01-06

    The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highly oriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosizeareas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.

  17. Addressing a single spin in diamond with a macroscopic dielectric microwave cavity

    SciTech Connect (OSTI)

    Le Floch, J.-M.; Tobar, M. E.; Bradac, C.; Nand, N.; Volz, T.; Castelletto, S.

    2014-09-29

    We present a technique for addressing single nitrogen-vacancy (NV) center spins in diamond over macroscopic distances using a tunable dielectric microwave cavity. We demonstrate optically detected magnetic resonance (ODMR) for a single negatively charged NV center (NV{sup –}) in a nanodiamond (ND) located directly under the macroscopic microwave cavity. By moving the cavity relative to the ND, we record the ODMR signal as a function of position, mapping out the distribution of the cavity magnetic field along one axis. In addition, we argue that our system could be used to determine the orientation of the NV{sup –} major axis in a straightforward manner.

  18. Cleaning of diamond nanoindentation probes with oxygen plasma and carbon dioxide snow

    SciTech Connect (OSTI)

    Morris, Dylan J. [National Institute of Standards and Technology, Materials Science and Engineering Laboratory, 100 Bureau Drive, Mail Stop 8520, Gaithersburg, Maryland 20899-8520 (United States)

    2009-12-15

    Diamond nanoindentation probes may perform thousands of indentations over years of service life. There is a broad agreement that the probes need frequent cleaning, but techniques for doing so are mostly anecdotes shared between experimentalists. In preparation for the measurement of the shape of a nanoindentation probe by a scanning probe microscope, cleaning by carbon dioxide snow jets and oxygen plasma was investigated. Repeated indentation on a thumbprint-contaminated surface formed a compound that was very resistant to removal by solvents, CO{sub 2} snow, and plasma. CO{sub 2} snow cleaning is found to be a generally effective cleaning procedure.

  19. Pretreatment process for forming a smooth surface diamond film on a carbon-coated substrate

    DOE Patents [OSTI]

    Feng, Zhu (Albany, CA); Brewer, Marilee (Goleta, CA); Brown, Ian (Berkeley, CA); Komvopoulos, Kyriakos (Orinda, CA)

    1994-01-01

    A process is disclosed for the pretreatment of a carbon-coated substrate to provide a uniform high density of nucleation sites thereon for the subsequent deposition of a continuous diamond film without the application of a bias voltage to the substrate. The process comprises exposing the carbon-coated substrate, in a microwave plasma enhanced chemical vapor deposition system, to a mixture of hydrogen-methane gases, having a methane gas concentration of at least about 4% (as measured by partial pressure), while maintaining the substrate at a pressure of about 10 to about 30 Torr during the pretreatment.

  20. Solar-induced chemical vapor deposition of diamond-type carbon films

    DOE Patents [OSTI]

    Pitts, J. Roland (Lakewood, CO); Tracy, C. Edwin (Golden, CO); King, David E. (Lakewood, CO); Stanley, James T. (Beaverton, OR)

    1994-01-01

    An improved chemical vapor deposition method for depositing transparent continuous coatings of sp.sup.3 -bonded diamond-type carbon films, comprising: a) providing a volatile hydrocarbon gas/H.sub.2 reactant mixture in a cold wall vacuum/chemical vapor deposition chamber containing a suitable substrate for said films, at pressure of about 1 to 50 Torr; and b) directing a concentrated solar flux of from about 40 to about 60 watts/cm.sup.2 through said reactant mixture to produce substrate temperatures of about 750.degree. C. to about 950.degree. C. to activate deposition of the film on said substrate.

  1. Solar-induced chemical vapor deposition of diamond-type carbon films

    DOE Patents [OSTI]

    Pitts, J.R.; Tracy, C.E.; King, D.E.; Stanley, J.T.

    1994-09-13

    An improved chemical vapor deposition method for depositing transparent continuous coatings of sp[sup 3]-bonded diamond-type carbon films, comprises: (a) providing a volatile hydrocarbon gas/H[sub 2] reactant mixture in a cold wall vacuum/chemical vapor deposition chamber containing a suitable substrate for said films, at pressure of about 1 to 50 Torr; and (b) directing a concentrated solar flux of from about 40 to about 60 watts/cm[sup 2] through said reactant mixture to produce substrate temperatures of about 750 C to about 950 C to activate deposition of the film on said substrate. 11 figs.

  2. High stability electron field emitters made of nanocrystalline diamond coated carbon nanotubes

    SciTech Connect (OSTI)

    Sankaran, K. J.; Tai, N. H., E-mail: nhtai@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Srinivasu, K.; Leou, K. C. [Department of Engineering and System Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China)] [Department of Engineering and System Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Lin, I. N., E-mail: inanlin@mail.tku.edu.tw [Department of Physics, Tamkang University, Tamsui 251, Taiwan (China)

    2013-12-16

    We report enhanced life-time stability for the electron field emitters prepared by coating nanocrystalline diamond (NCD) on carbon nanotubes (CNTs). Upon overcoming the problem of poor stability in CNTs, the NCD-CNTs exhibit excellent life-time stability of 250 min tested at different applied voltages of 600 and 900?V. In contrast, the life-time stability of CNTs is only 33 min even at relatively low voltage of 360?V and starts arcing at 400?V. Hence, the NCD-CNTs with improved life-time stability have great potential for the applications as cathodes in flat panel displays and microplasma display devices.

  3. Storage and retrieval of ultrafast single photons using a room-temperature diamond quantum memory

    E-Print Network [OSTI]

    Duncan G. England; Kent A. G. Fisher; Jean-Philippe W. MacLean; Philip J. Bustard; Rune Lausten; Kevin J. Resch; Benjamin J. Sussman

    2014-09-11

    We report the storage and retrieval of single photons, via a quantum memory, in the optical phonons of room-temperature bulk diamond. The THz-bandwidth heralded photons are generated by spontaneous parametric downconversion and mapped to phonons via a Raman transition, stored for a variable delay, and released on demand. The second-order correlation of the memory output is $g^{(2)}(0) = 0.65 \\pm 0.07$, demonstrating preservation of non-classical photon statistics throughout storage and retrieval. The memory is low-noise, high-speed and broadly tunable; it therefore promises to be a versatile light-matter interface for local quantum processing applications.

  4. One- and two-dimensional nuclear magnetic resonance spectroscopy with a diamond quantum sensor

    E-Print Network [OSTI]

    J. M. Boss; K. Chang; J. Armijo; K. Cujia; T. Rosskopf; J. R. Maze; C. L. Degen

    2015-12-10

    We report on Fourier spectroscopy experiments performed with near-surface nitrogen-vacancy centers in a diamond chip. By detecting the free precession of nuclear spins rather than applying a multipulse quantum sensing protocol, we are able to unambiguously identify the NMR species devoid of harmonics. We further show that by engineering different Hamiltonians during free precession, the hyperfine coupling parameters as well as the nuclear Larmor frequency can be selectively measured with high precision (here 5 digits). The protocols can be combined to demonstrate two-dimensional Fourier spectroscopy. The technique will be useful for mapping nuclear coordinates in molecules en route to imaging their atomic structure.

  5. Recursive polarization of nuclear spins in diamond at arbitrary magnetic fields

    SciTech Connect (OSTI)

    Pagliero, Daniela; Laraoui, Abdelghani; Henshaw, Jacob D.; Meriles, Carlos A.

    2014-12-15

    We introduce an alternate route to dynamically polarize the nuclear spin host of nitrogen-vacancy (NV) centers in diamond. Our approach articulates optical, microwave, and radio-frequency pulses to recursively transfer spin polarization from the NV electronic spin. Using two complementary variants of the same underlying principle, we demonstrate nitrogen nuclear spin initialization approaching 80% at room temperature both in ensemble and single NV centers. Unlike existing schemes, our approach does not rely on level anti-crossings and is thus applicable at arbitrary magnetic fields. This versatility should prove useful in applications ranging from nanoscale metrology to sensitivity-enhanced NMR.

  6. An ultra-thin diamond membrane as a transmission particle detector and vacuum window for external microbeams

    SciTech Connect (OSTI)

    Grilj, V.; Skukan, N.; Jakši?, M.; Pomorski, M.; Kada, W.; Iwamoto, N.; Kamiya, T.; Ohshima, T.

    2013-12-09

    Several applications of external microbeam techniques demand a very accurate and controlled dose delivery. To satisfy these requirements when post-sample ion detection is not feasible, we constructed a transmission single-ion detector based on an ultra-thin diamond membrane. The negligible intrinsic noise provides an excellent signal-to-noise ratio and enables a hit-detection efficiency of close to 100%, even for energetic protons, while the small thickness of the membrane limits beam spreading. Moreover, because of the superb mechanical stiffness of diamond, this membrane can simultaneously serve as a vacuum window and allow the extraction of an ion microbeam into the atmosphere.

  7. Jets from Tidal Disruptions of Stars by Black Holes

    E-Print Network [OSTI]

    Julian H. Krolik; Tsvi Piran

    2012-02-07

    Tidal disruption of main sequence stars by black holes has generally been thought to lead to a signal dominated by UV emission. If, however, the black hole spins rapidly and the poloidal magnetic field intensity on the black hole horizon is comparable to the inner accretion disk pressure, a powerful jet may form whose luminosity can easily exceed the thermal UV luminosity. When the jet beam points at Earth, its non-thermal luminosity can dominate the emitted spectrum. The thermal and non-thermal components decay differently with time. In particular, the thermal emission should remain roughly constant for a significant time after the period of maximum accretion, beginning to diminish only after a delay, whereas after the peak accretion rate, the non-thermal jet emission decays, but then reaches a plateau. Both transitions are tied to a characteristic timescale $t_{\\rm Edd}$ at which the accretion rate falls below Eddington. Making use of this timescale in a new parameter-inference formalism for tidal disruption events with significant emission from a jet, we analyze the recent flare source Swift J2058. It is consistent with an event in which a main sequence solar-type staris disrupted by a black hole of mass $\\sim 4 \\times 10^7 M_{\\odot}$. The beginning of the flat phase in the non-thermal emission from this source can possibly be seen in the late-time lightcurve. Optical photometry over the first $\\simeq 40$ d of this flare is also consistent with this picture, but is only weakly constraining because the bolometric correction is very uncertain. We suggest that future searches for main sequence tidal disruptions use methods sensitive to jet radiation as well as to thermal UV radiation.

  8. L.A. Rebellion: Creating a New Black Cinema

    E-Print Network [OSTI]

    Sheppard, Samantha Noelle

    2011-01-01

    Creating a New Black Cinema Symposium Review by SamanthaCreating a New Black Cinema By the turn of the next century,in the development of Black cinema took place at UCLA in the

  9. Queering Black Gay Historiography: Performance, (Mis) Identifications, and Possibilities

    E-Print Network [OSTI]

    Fitzgerald, Thomas Howard

    2013-01-01

    In 1976 the black comedy Car Wash featured a black gay manthe a openly black sissy in the Car Wash as a character thatsaw the distribution of Car Wash with Antoino Fargas playing

  10. Extraordinary vacuum black string solutions

    SciTech Connect (OSTI)

    Kim, Hyeong-Chan; Lee, Jungjai

    2008-01-15

    In addition to the boosted static solution there are two other classes of stationary stringlike solutions of the vacuum Einstein equation in (4+1) dimensions. Each class is characterized by three parameters of mass, tension, and momentum flow along the fifth coordinate. We analyze the metric properties of one of the two classes, which was previously assumed to be naked singular, and show that the solution spectrum contains black string and wormhole in addition to the known naked singularity as the momentum flow to mass ratio increases. Interestingly, there does not exist new zero momentum solution in these cases.

  11. Power LCAT

    SciTech Connect (OSTI)

    Drennen, Thomas

    2012-08-15

    POWER LCAT is a software tool used to compare elements of efficiency, cost, and environmental effects between different sources of energy.

  12. QM Power

    Broader source: Energy.gov [DOE]

    QM Power’s Q-Sync™ is an innovative, highly efficient and cost effective motor technology. Utilizing DoE SBIR funding, QM Power has developed advanced Q-Sync fan motor technology for 9-12 watt commercial refrigeration fan applications and is launching its first product lines targeting both new and existing commercial refrigeration equipment. For this project, QM Power will team with Oak Ridge National Labs, market leading OEMs, subject matter experts, end users, retrofit contractors and utilities to install and demonstrate approximately 10,000 high efficiency Q-Sync fan motors in over 50 grocery sites throughout the US.

  13. Power LCAT

    ScienceCinema (OSTI)

    Drennen, Thomas

    2014-06-27

    POWER LCAT is a software tool used to compare elements of efficiency, cost, and environmental effects between different sources of energy.

  14. Effective theories and black hole production in warped compactificatio...

    Office of Scientific and Technical Information (OSTI)

    Effective theories and black hole production in warped compactifications Citation Details In-Document Search Title: Effective theories and black hole production in warped...

  15. Effects of intermediate mass black holes on nuclear star clusters

    SciTech Connect (OSTI)

    Mastrobuono-Battisti, Alessandra; Perets, Hagai B.; Loeb, Abraham

    2014-11-20

    Nuclear star clusters (NSCs) are dense stellar clusters observed in galactic nuclei, typically hosting a central massive black hole. Here we study the possible formation and evolution of NSCs through the inspiral of multiple star clusters hosting intermediate mass black holes (IMBHs). Using an N-body code, we examine the dynamics of the IMBHs and their effects on the NSC. We find that IMBHs inspiral to the core of the newly formed NSC and segregate there. Although the IMBHs scatter each other and the stars, none of them is ejected from the NSC. The IMBHs are excited to high eccentricities and their radial density profile develops a steep power-law cusp. The stars also develop a power-law cusp (instead of the central core that forms in their absence), but with a shallower slope. The relaxation rate of the NSC is accelerated due to the presence of IMBHs, which act as massive perturbers. This in turn fills the loss cone and boosts the tidal disruption rate of stars both by the MBH and the IMBHs to a value excluded by rate estimates based on current observations. Rate estimates of tidal disruptions can therefore provide a cumulative constraint on the existence of IMBHs in NSCs.

  16. Optimizing a dynamical decoupling protocol for solid-state electronic spin ensembles in diamond

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

    Farfurnik, D.; Jarmola, A.; Pham, L. M.; Wang, Z. H.; Dobrovitski, V. V.; Walsworth, R. L.; Budker, D.; Bar-Gill, N.

    2015-08-24

    We demonstrate significant improvements of the spin coherence time of a dense ensemble of nitrogen-vacancy (NV) centers in diamond through optimized dynamical decoupling (DD). Cooling the sample down to 77 K suppresses longitudinal spin relaxation T1 effects and DD microwave pulses are used to increase the transverse coherence time T2 from ~0.7ms up to ~30ms. Furthermore, we extend previous work of single-axis (Carr-Purcell-Meiboom-Gill) DD towards the preservation of arbitrary spin states. Following a theoretical and experimental characterization of pulse and detuning errors, we compare the performance of various DD protocols. We also identify that the optimal control scheme for preservingmore »an arbitrary spin state is a recursive protocol, the concatenated version of the XY8 pulse sequence. The improved spin coherence might have an immediate impact on improvements of the sensitivities of ac magnetometry. Moreover, the protocol can be used on denser diamond samples to increase coherence times up to NV-NV interaction time scales, a major step towards the creation of quantum collective NV spin states.« less

  17. Grain size dependent mechanical properties of nanocrystalline diamond films grown by hot-filament CVD

    SciTech Connect (OSTI)

    Wiora, M; Bruehne, K; Floeter, A; Gluche, P; Willey, T M; Kucheyev, S O; Van Buuren, A W; Hamza, A V; Biener, J; Fecht, H

    2008-08-01

    Nanocrystalline diamond (NCD) films with a thickness of {approx}6 {micro}m and with average grain sizes ranging from 60 to 9 nm were deposited on silicon wafers using a hot-filament chemical vapor deposition (HFCVD) process. These samples were then characterized with the goal to identify correlations between grain size, chemical composition and mechanical properties. The characterization reveals that our films are phase pure and exhibit a relatively smooth surface morphology. The levels of sp{sup 2}-bonded carbon and hydrogen impurities are low, and showed a systematic variation with the grain size. The hydrogen content increases with decreasing grain size, whereas the sp{sup 2} carbon content decreases with decreasing grain size. The material is weaker than single crystalline diamond, and both stiffness and hardness decrease with decreasing grain size. These trends suggest gradual changes of the nature of the grain boundaries, from graphitic in the case of the 60 nm grain size material to hydrogen terminated sp{sup 3} carbon for the 9 nm grain size material. The films exhibit low levels of internal stress and freestanding structures with a length of several centimeters could be fabricated without noticeable bending.

  18. Magneto-optical imaging of thin magnetic films using spins in diamond

    E-Print Network [OSTI]

    David A. Simpson; Jean-Philippe Tetienne; Julia McCoey; Kumaravelu Ganesan; Liam T. Hall; Steven Petrou; Robert E. Scholten; Lloyd C. L. Hollenberg

    2015-08-10

    Imaging the fields of magnetic materials provides crucial insight into the physical and chemical processes surrounding magnetism, and has been a key ingredient in the spectacular development of magnetic data storage. Existing approaches using the magneto-optic Kerr effect (MOKE), x-ray and electron microscopy have limitations that constrain further development, and there is increasing demand for imaging and characterisation of magnetic phenomena in real time with high spatial resolution. In this work, we show how the magneto-optical response of an array of negatively-charged nitrogen-vacancy spins in diamond can be used to image and map the sub-micron stray magnetic field patterns from thin ferromagnetic films. Using optically detected magnetic resonance, we demonstrate wide-field magnetic imaging over 100x100 {\\mu}m^2 with a diffraction-limited spatial resolution of 440 nm at video frame rates, under ambient conditions. We demonstrate a novel all-optical spin relaxation contrast imaging approach which can image magnetic structures in the absence of an applied microwave field. Straightforward extensions promise imaging with sub-{\\mu}T sensitivity and sub-optical spatial and millisecond temporal resolution. This work establishes practical diamond-based wide-field microscopy for rapid high-sensitivity characterisation and imaging of magnetic samples, with the capability for investigating magnetic phenomena such as domain wall and skyrmion dynamics and the spin Hall effect in metals.

  19. On Monic Gr\\"obner Bases in Free Algebras over Rings Stemming from Bergman's Diamond Lemma

    E-Print Network [OSTI]

    Li, Huishi

    2009-01-01

    Let $R$ be an arbitrary commutative ring and $R =R$ the free algebra of $n$ generators over $R$. Note that Bergman's diamond lemma characterizes the resolvability of ambiguities of monic relations of the form $W_{\\sigma}-f_{\\sigma}$ with $f_{\\sigma}$ a linear combination of monomials $\\prec W_{\\sigma}$, where $\\prec$ is a semigroup partial ordering on $$; and that in the algorithmic language of Gr\\"obner basis theory over a ground field $K$, the diamond lemma had been translated into the implementable termination theorem. Here we bring the termination theorem over $R$ into play so that monic Gr\\"obner Bases in $R$ may be verified in an effective way, though it does not necessarily yield a noncommutative analogue of Buchberger Algorithm in such a setting. This enables us to recognize that many important algebras over rings may have Gr\\"obner defining relations, and thereby enables us to study such algebras via their $\\mathbb{N}$-leading homogeneous algebra and ${\\cal B}_R$-leading homogeneous algebra.

  20. An electromagnetic black hole made of metamaterials

    E-Print Network [OSTI]

    Qiang Cheng; Tie Jun Cui; Wei Xiang Jiang; Ben Geng Cai

    2010-04-30

    Traditionally, a black hole is a region of space with huge gravitational field, which absorbs everything hitting it. In history, the black hole was first discussed by Laplace under the Newton mechanics, whose event horizon radius is the same as the Schwarzschild's solution of the Einstein's vacuum field equations. If all those objects having such an event horizon radius but different gravitational fields are called as black holes, then one can simulate certain properties of the black holes using electromagnetic fields and metamaterials due to the similar propagation behaviours of electromagnetic waves in curved space and in inhomogeneous metamaterials. In a recent theoretical work by Narimanov and Kildishev, an optical black hole has been proposed based on metamaterials, in which the theoretical analysis and numerical simulations showed that all electromagnetic waves hitting it are trapped and absorbed. Here we report the first experimental demonstration of such an electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can trap and absorb electromagnetic waves coming from all directions spirally inwards without any reflections due to the local control of electromagnetic fields and the event horizon corresponding to the device boundary. It is shown that the absorption rate can reach 99% in the microwave frequencies. We expect that the electromagnetic black hole could be used as the thermal emitting source and to harvest the solar light.

  1. Black holes cannot support conformal scalar hair

    E-Print Network [OSTI]

    T. Zannias

    1994-09-14

    It is shown that the only static asymptotically flat non-extrema black hole solution of the Einstein-conformally invariant scalar field equations having the scalar field bounded on the horizon, is the Schwarzschild one. Thus black holes cannot be endowed with conformal scalar hair of finite length.

  2. Quantum Entropy of Charged Rotating Black Holes

    E-Print Network [OSTI]

    R. B. Mann

    1996-07-10

    I discuss a method for obtaining the one-loop quantum corrections to the tree-level entropy for a charged Kerr black hole. Divergences which appear can be removed by renormalization of couplings in the tree-level gravitational action in a manner similar to that for a static black hole.

  3. Topological Black Holes in Quantum Gravity

    E-Print Network [OSTI]

    J. Kowalski-Glikman; D. Nowak-Szczepaniak

    2000-07-31

    We derive the black hole solutions with horizons of non-trivial topology and investigate their properties in the framework of an approach to quantum gravity being an extension of Bohm's formulation of quantum mechanics. The solutions we found tend asymptotically (for large $r$) to topological black holes. We also analyze the thermodynamics of these space-times.

  4. Primordial black holes and asteroid danger

    E-Print Network [OSTI]

    Alexander Shatskiy

    2008-02-21

    Probability for a primordial black hole to invade the Kuiper belt was calculated. We showed that primordial black holes of certain masses can significantly change asteroids' orbits. These events may result in disasters, local for our solar system and global for the Earth (like the Tunguska meteorite). We also estimated how often such events occur.

  5. Stability of AdS black strings

    E-Print Network [OSTI]

    T. Delsate

    2008-08-14

    We review the recent developements in the stability problem and phase diagram for asymptotically locally $AdS$ black strings. First, we quickly review the case of locally flat black string before turning to the case of locally $AdS$ spacetimes.

  6. Canonical structure of 2D black holes

    E-Print Network [OSTI]

    Navarro-Salas, J; Talavera, C F

    1994-01-01

    We determine the canonical structure of two-dimensional black-hole solutions arising in $2D$ dilaton gravity. By choosing the Cauchy surface appropriately we find that the canonically conjugate variable to the black hole mass is given by the difference of local (Schwarzschild) time translations at right and left spatial infinities. This can be regarded as a generalization of Birkhoff's theorem.

  7. Fractal Statistics and Quantum Black Hole Entropy

    E-Print Network [OSTI]

    Wellington da Cruz

    2000-11-18

    Simple considerations about the fractal characteristic of the quantum-mechanical path give us the opportunity to derive the quantum black hole entropy in connection with the concept of fractal statistics. We show the geometrical origin of the numerical factor of four of the quantum black hole entropy expression and the statistics weight appears as a counting of the quanta of geometry.

  8. Can Superconducting Cosmic Strings Piercing Seed Black Holes Generate Supermassive Black Holes in the Early Universe?

    E-Print Network [OSTI]

    Lake, Matthew J

    2015-01-01

    The discovery of a large number of supermassive black holes at redshifts $z> 6$, when the Universe was only nine hundred million years old, has raised the fundamental question of how such massive compact objects could form in a (cosmologically) short time interval. Each of the proposed standard scenarios for black hole formation, involving rapid accretion of seed black holes, or black hole mergers, faces severe theoretical difficulties in explaining the short time formation of supermassive objects. In the present Letter, we propose an alternative scenario for the formation of supermassive black holes in the early Universe in which energy transfer from superconducting cosmic strings, piercing small seed black holes, is the main physical process leading to rapid mass increase. The increase in mass of a primordial seed black hole pierced by two antipodal strings is estimated and it is shown that this increases linearly in time. Due to the high energy transfer rate from the cosmic strings, we find that supermassi...

  9. Class Transitions in Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    A black hole spectrum is known to change from the hard state to the soft state when the energy spectral index $\\alpha$ ($F_E \\propto E^{-\\alpha}$) in, say, 2-20 keV range changes from $\\alpha \\sim 0.5$ to $\\sim 1.5$. However, this `classical' definition which characterizes black holes like Cyg X-1, becomes less useful for many objects such as GRS 1915+105 in which the spectral slope is seen to vary from one to the other in a matter of seconds and depending on whether or not winds form, the spectral slope also changes. The light curves and the colour-colour diagrams may look completely different on different days depending on the frequency and mode of switching from one spectral state to the other. Though RXTE observations have yielded wealth of information on such `variability classes' in GRS 1915+105, very rarely one has been able to observe how the object goes from one class to the other. In the present review, we discuss possible origins of the class transition and present several examples of such transitions. In this context, we use mostly the results of the Indian X-ray Astronomy Experiment (IXAE) which observed GRS 1915+105 more regularly.

  10. Nonthermal correction to black hole spectroscopy

    E-Print Network [OSTI]

    Wen-Yu Wen

    2014-11-14

    Area spectrum of black holes have been obtained via various methods such as quasinormal modes, adiabatic invariance and angular momentum. Among those methods, calculations were done by assuming black holes in thermal equilibrium. Nevertheless, black holes in the asymptotically flat space usually have negative specific heat and therefore tend to stay away from thermal equilibrium. Even for those black holes with positive specific heat, temperature may still not be well defined in the process of radiation, due to the back reaction of decreasing mass. Respect to these facts, it is very likely that Hawking radiation is nonthermal and the area spectrum is no longer equidistant. In this note, we would like to illustrate how the area spectrum of black holes is corrected by this nonthermal effect.

  11. Fourier Analysis of the BTZ Black Hole

    E-Print Network [OSTI]

    Ian M. Tolfree

    2009-11-11

    In this paper we extend our previous work regarding the role of the Fourier transformation in bulk to boundary mappings to include the BTZ black hole. We follow standard procedures for modifying Fourier Transformations to accommodate quotient spaces and arrive at a bulk to boundary mapping in a black hole background. We show that this mapping is consistent with known results and lends a new insight into the AdS/CFT duality. We find that the micro-states corresponding to the entropy of a bulk scalar field are the Fourier coefficients on the boundary, which transform under the principal series representation of $SL(2,R)$. Building upon this we present a toy model to analyze the implications of this for the origin of black hole entropy. We find that the black hole micro-states live on the boundary and correspond to the possible emission modes of the black hole

  12. Evidence for the Black Hole Event Horizon

    E-Print Network [OSTI]

    Ramesh Narayan

    2003-10-23

    Astronomers have discovered many candidate black holes in X-ray binaries and in the nuclei of galaxies. The candidate objects are too massive to be neutron stars, and for this reason they are considered to be black holes. While the evidence based on mass is certainly strong, there is no proof yet that any of the objects possesses the defining characteristic of a black hole, namely an event horizon. Type I X-ray bursts, which are the result of thermonuclear explosions when gas accretes onto the surface of a compact star, may provide important evidence in this regard. Type I bursts are commonly observed in accreting neutron stars, which have surfaces, but have never been seen in accreting black hole candidates. It is argued that the lack of bursts in black hole candidates is compelling evidence that these objects do not have surfaces. The objects must therefore possess event horizons.

  13. How fast can a black hole rotate?

    E-Print Network [OSTI]

    Herdeiro, Carlos A R

    2015-01-01

    Kerr black holes have their angular momentum, $J$, bounded by their mass, $M$: $Jc\\leqslant GM^2$. There are, however, known black hole solutions violating this Kerr bound. We propose a very simple universal bound on the rotation, rather than on the angular momentum, of four-dimensional, stationary and axisymmetric, asymptotically flat black holes, given in terms of an appropriately defined horizon linear velocity, $v_H$. The $v_H$ bound is simply that $v_H$ cannot exceed the velocity of light. We verify the $v_H$ bound for known black hole solutions, including some that violate the Kerr bound, and conjecture that only extremal Kerr black holes saturate the $v_H$ bound.

  14. Howard J. Diamond, U.S. GCOS Program Manager, National Climatic Data Center (NCDC), National Oceanic and Atmospheric Administration (NOAA)

    E-Print Network [OSTI]

    Howard J. Diamond, U.S. GCOS Program Manager, National Climatic Data Center (NCDC), National Oceanic and Atmospheric Administration (NOAA) Director, World Data Center for Meteorology Tel : +1 System Program Manager Director, World Data Center for Meteorology Formal NOAA Lead on U.S. climate bi

  15. Z .Diamond and Related Materials 10 2001 1947 1951 Synthesis of high-density carbon nanotube films by microwave

    E-Print Network [OSTI]

    Tománek, David

    and vertical growth rate of nanotubes. The growth rate on an iron-coated substrate is higher than on a nickel. Nanotubes in the present study are fabricated by MPCVD using iron Z . Z .Fe or nickel Ni as transition metalZ .Diamond and Related Materials 10 2001 1947 1951 Synthesis of high-density carbon nanotube films

  16. Does the Use of Diamond-Like Carbon Coating and Organophosphate Lubricant Additive Together Cause Excessive Tribochemical Material Removal?

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

    Zhou, Yan; Leonard, Donovan N.; Meyer, Harry M.; Luo, Huimin; Qu, Jun

    2015-08-22

    We observe unexpected wear increase on a steel surface that rubbed against diamond-like carbon (DLC) coatings only when lubricated by phosphate-based antiwear additives. Contrary to the literature hypothesis of a competition between zinc dialkyldithiophosphate produced tribofilms and DLC-induced carbon transfer, here a new wear mechanism based on carbon-catalyzed tribochemical interactions supported by surface characterization is proposed

  17. Power system

    DOE Patents [OSTI]

    Hickam, Christopher Dale (Glasford, IL)

    2008-03-18

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  18. Symmetry and the arrow of time in theoretical black hole astrophysics

    E-Print Network [OSTI]

    David Garofalo

    2015-07-27

    While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the underlying theoretical structure from which this accreting black hole framework emerges displays a time-symmetric harmonic behavior, a feature reminiscent of basic and simple laws of physics. While we may expect such behavior for classical black holes due to their simplicity, manifestations of such symmetry on the scale of galaxies, instead, surprise. In fact, we identify a parallel between the astrophysical tug-of-war between accretion disks and jets in this model and the time symmetry-breaking of a simple overdamped harmonic oscillator. The validity of these theoretical ideas in combination with this unexpected parallel suggests that black holes are more influential in astrophysics than currently recognized and that black hole astrophysics is a more fundamental discipline.

  19. A complex state transition from the black hole candidate Swift J1753.5-0127

    E-Print Network [OSTI]

    Soleri, P; Motta, S; Belloni, T; Casella, P; Méndez, M; Altamirano, D; Linares, M; Wijnands, R; Fender, R; van der Klis, M

    2012-01-01

    We present our monitoring campaign of the outburst of the black-hole candidate Swift J1753.5-0127, observed with the Rossi X-ray Timing Explorer and the Swift satellites. After ~4.5 years since its discovery, the source had a transition to the hard intermediate state. We performed spectral and timing studies of the transition showing that, unlike the majority of the transient black holes, the system did not go to the soft states but it returned to the hard state after a few months. During this transition Swift J1753.5-0127 features properties which are similar to those displayed by the black hole Cygnus X-1. We compared Swift J1753.5-0127 to one dynamically confirmed black hole and two neutron stars showing that its power spectra are in agreement with the binary hosting a black hole. We also suggest that the prolonged period at low flux that followed the initial flare is reminiscent of that observed in other X-ray binaries, as well as in cataclysmic variables.

  20. Experimental Evaluation of Beam to Diamond Box Column Connection with Through Plate in Moment Frames

    SciTech Connect (OSTI)

    Keshavarzi, Farhad; Torabian, Shahabeddin; Imanpour, Ali; Mirghaderi, Rasoul

    2008-07-08

    Moment resisting frames with built up section have very enhanced features due to high bending stiffness and strength characteristics in two principal axes and access to column faces for beam to column easy connections. But due to proper transfer of beam stresses to column faces there were always some specific controvertibly issues that how to make the load transfer through and in plane manner in order to mobilize the forces in column faces. Using diamond column instead of box column provide possibility to mobilize the load transfer mechanism in column faces. This section as a column has considerable benefit such as high plastic to elastic section modulus ratio which is an effective factor for force controlled components. Typical connection has no chance to be applied with diamond column.This paper elucidates the seismic behavior of through-plates moment connections to diamond box columns for use in steel moment resisting frames. This connection has a lot of economical benefits such as no need to horizontal continuity plates and satisfying the weak beam--strong column criteria in the connection region. They might serve as panel zone plates as well. According to high shear demand in panel zone of beam to column joint one should use the doublers plates in order to decrease the shear strength demand in this sensitive part of structure but these plates have no possibility to mobilize the load transfer mechanism in column web and transfer them to column flanges. In this type of connection, column faces have effective role in order to decrease the demands on through plate and they are impressive factors for improving the performance of the connection.Experimental analysis was conducted to elucidate the seismic behavior of this connection. The results of Experimental analysis established the effectiveness of the through plate in mitigating local stress concentrations and forming the plastic hinge zone in the beam away from the beam to column interface. The moment-rotation graphs form sub-assemblage show a desirable seismic performance of this connection.

  1. Journal of Information Processing Systems, Vol.5, No.4, December 2009 167 Black Bridge: A Scatternet Formation Algorithm for Solving a New

    E-Print Network [OSTI]

    Guo, Minyi

    , the new technology named after the 10th Century Danish King Harold Bluetooth, is an always on, low-powerJournal of Information Processing Systems, Vol.5, No.4, December 2009 167 Black Bridge capabilities using the 2.4 GHz band which is available globally for unlicensed low-power uses. And Bluetooth

  2. Report on the WORKSHOP ON COMMERCIALIZATION OF BLACK LIQUOR

    E-Print Network [OSTI]

    .3. Gasifier Supplier Perspectives 11 Black Liquor Gasifier Suppliers 12 Biomass Gasifier Suppliers 13 5

  3. Testing black hole candidates with electromagnetic radiation

    E-Print Network [OSTI]

    Bambi, Cosimo

    2015-01-01

    Astrophysical black hole candidates are thought to be the Kerr black holes of general relativity, but there is currently no direct observational evidence that the spacetime geometry around these objects is described by the Kerr solution. The study of the properties of the electromagnetic radiation emitted by gas or stars orbiting these objects can potentially test the Kerr black hole hypothesis. In this paper, I review the state of the art of this research field, describing the possible approaches to test the Kerr metric with current and future observational facilities and discussing current constraints.

  4. Quasinormal Modes of Dirty Black Holes

    E-Print Network [OSTI]

    P. T. Leung; Y. T. Liu; W. -M. Suen; C. Y. Tam; K. Young

    1999-03-08

    Quasinormal mode (QNM) gravitational radiation from black holes is expected to be observed in a few years. A perturbative formula is derived for the shifts in both the real and the imaginary part of the QNM frequencies away from those of an idealized isolated black hole. The formulation provides a tool for understanding how the astrophysical environment surrounding a black hole, e.g., a massive accretion disk, affects the QNM spectrum of gravitational waves. We show, in a simple model, that the perturbed QNM spectrum can have interesting features.

  5. Black Hole Thermodynamics and Statistical Mechanics

    E-Print Network [OSTI]

    Steven Carlip

    2008-07-28

    We have known for more than thirty years that black holes behave as thermodynamic systems, radiating as black bodies with characteristic temperatures and entropies. This behavior is not only interesting in its own right; it could also, through a statistical mechanical description, cast light on some of the deep problems of quantizing gravity. In these lectures, I review what we currently know about black hole thermodynamics and statistical mechanics, suggest a rather speculative "universal" characterization of the underlying states, and describe some key open questions.

  6. Some remarks on black hole thermodynamics

    E-Print Network [OSTI]

    R. Y. Chiao

    2011-02-04

    Two thermodynamic "paradoxes" of black hole physics are re-examined. The first is that there is a thermal instability involving two coupled blackbody cavities containing two black holes, and second is that a classical black hole can swallow up entropy in the form of ambient blackbody photons without increasing its mass. The resolution of the second paradox by Bekenstein and by Hawking is re-visited. The link between Hawking radiation and Wigner's superluminal tunneling time is discussed using two equivalent Feynman diagrams, and Feynman's re-interpretation principle.

  7. Thermodynamics of Dyonic Lifshitz Black Holes

    E-Print Network [OSTI]

    Tobias Zingg

    2011-07-15

    Black holes with asymptotic anisotropic scaling are conjectured to be gravity duals of condensed matter system close to quantum critical points with non-trivial dynamical exponent z at finite temperature. A holographic renormalization procedure is presented that allows thermodynamic potentials to be defined for objects with both electric and magnetic charge in such a way that standard thermodynamic relations hold. Black holes in asymptotic Lifshitz spacetimes can exhibit paramagnetic behavior at low temperature limit for certain values of the critical exponent z, whereas the behavior of AdS black holes is always diamagnetic.

  8. Testing the Kerr black hole hypothesis

    E-Print Network [OSTI]

    Cosimo Bambi

    2011-10-13

    It is thought that the final product of the gravitational collapse is a Kerr black hole and astronomers have discovered several good astrophysical candidates. While there is some indirect evidence suggesting that the latter have an event horizon, and therefore that they are black holes, a proof that the space-time around these objects is described by the Kerr geometry is still lacking. Recently, there has been an increasing interest in the possibility of testing the Kerr black hole hypothesis with present and future experiments. In this paper, I briefly review the state of the art of the field, focussing on some recent results and work in progress.

  9. Scalar Perturbations of Charged Dilaton Black Holes

    E-Print Network [OSTI]

    Sharmanthie Fernando; Keith Arnold

    2015-08-01

    We have studied the scalar perturbation of static charged dilaton black holes in 3+1 dimensions. The black hole considered here is a solution to the low-energy string theory in 3+1 dimensions. The quasinormal modes for the scalar perturbations are calculated using the third order WKB method. The dilaton coupling constant has a considerable effect on the values of quasi normal modes. It is also observed that there is a linear relation between the quasi normal modes and the temperature for large black holes.

  10. Energy density bounds for black strings

    E-Print Network [OSTI]

    Shinya Tomizawa

    2005-06-07

    The conserved charge called Y-ADM mass density associated with asymptotically translational Killing-Yano tensor gives us an appropriate physical meaning about the energy density of $p$ brane spacetimes or black strings. We investigated the positivity of energy density in black string spacetimes, using the spinorial technique introduced by Witten. Recently, the positivity of Y-ADM mass density in p brane spacetimes was discussed. In this paper, we will extend this discussion to the transversely asymptotically flat black string spacetimes containing an apparent horizon. We will give the sufficient conditions for the Y-ADM mass density to become positive in such spacetimes.

  11. Nuclear Power 

    E-Print Network [OSTI]

    2010-01-01

    be inherently safe and environmentally benign. These realities of today's world are among the reasons that lead to serious interest in deploying nuclear power as a sustainable energy source. Today's nuclear reactors are safe and highly efficient energy systems...

  12. Power combiner

    DOE Patents [OSTI]

    Arnold, Mobius; Ives, Robert Lawrence

    2006-09-05

    A power combiner for the combining of symmetric and asymmetric traveling wave energy comprises a feed waveguide having an input port and a launching port, a reflector for reflecting launched wave energy, and a final waveguide for the collection and transport of launched wave energy. The power combiner has a launching port for symmetrical waves which comprises a cylindrical section coaxial to the feed waveguide, and a launching port for asymmetric waves which comprises a sawtooth rotated about a central axis.

  13. Power and environmental assessment: Introduction to the special issue

    SciTech Connect (OSTI)

    Cashmore, Matthew; Richardson, Tim

    2013-02-15

    The significance of politics and power dynamics has long been recognised in environmental assessment (EA) research, but there has not been sustained attention to power, either theoretically or empirically. The aim of this special issue is to encourage the EA community to engage more consistently with the issue of power. The introduction represents a ground-clearing exercise intended to clarify the terms of the debate about power in the EA field, and to contribute to the development of a research agenda. Research trends in the field are outlined, and potential analytic and normative lines of inquiry are identified. The contributions to this special issue represent contrasting conceptual and methodological approaches that navigate the analytical and normative terrain of power dynamics in EA. Together, they demonstrate that power cannot be removed from EA policy or practices, and is a necessary research focus for the development of the field. - Highlights: Black-Right-Pointing-Pointer Introduces the themed section on power Black-Right-Pointing-Pointer Provides an overview of the papers in the themed section Black-Right-Pointing-Pointer Identifies research trends and directions for future research.

  14. Photonic architecture for scalable quantum information processing in NV-diamond

    E-Print Network [OSTI]

    Kae Nemoto; Michael Trupke; Simon J. Devitt; Ashley M. Stephens; Kathrin Buczak; Tobias Nobauer; Mark S. Everitt; Jorg Schmiedmayer; William J. Munro

    2013-09-17

    Physics and information are intimately connected, and the ultimate information processing devices will be those that harness the principles of quantum mechanics. Many physical systems have been identified as candidates for quantum information processing, but none of them are immune from errors. The challenge remains to find a path from the experiments of today to a reliable and scalable quantum computer. Here, we develop an architecture based on a simple module comprising an optical cavity containing a single negatively-charged nitrogen vacancy centre in diamond. Modules are connected by photons propagating in a fiber-optical network and collectively used to generate a topological cluster state, a robust substrate for quantum information processing. In principle, all processes in the architecture can be deterministic, but current limitations lead to processes that are probabilistic but heralded. We find that the architecture enables large-scale quantum information processing with existing technology.

  15. Imaging shock waves in diamond with both high temporal and spatial resolution at an XFEL

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

    Schropp, Andreas; Hoppe, Robert; Meier, Vivienne; Patommel, Jens; Seiboth, Frank; Ping, Yuan; Hicks, Damien G.; Beckwith, Martha A.; Collins, Gilbert W.; Higginbotham, Andrew; et al

    2015-06-18

    The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range, and protein crystallography. In this article, we access a new field of science by measuring quantitatively the local bulk properties and dynamics of matter under extreme conditions, in this case by using the short XFEL pulse to image an elastic compression wave in diamond. The elastic wave was initiated by an intense optical laser pulse and was imaged at different delay times after the optical pump pulse using magnifiedmore »x-ray phase-contrast imaging. The temporal evolution of the shock wave can be monitored, yielding detailed information on shock dynamics, such as the shock velocity, the shock front width, and the local compression of the material. The method provides a quantitative perspective on the state of matter in extreme conditions.« less

  16. A superconducting cavity bus for single Nitrogen Vacancy defect centres in diamond

    E-Print Network [OSTI]

    J. Twamley; S. D. Barrett

    2009-12-18

    Circuit-QED has demonstrated very strong coupling between individual microwave photons trapped in a superconducting coplanar resonator and nearby superconducting qubits. In this work we show how, by designing a novel interconnect, one can strongly connect the superconducting resonator, via a magnetic interaction, to a small number (perhaps single), of electronic spins. By choosing the electronic spin to be within a Nitrogen Vacancy centre in diamond one can perform optical readout, polarization and control of this electron spin using microwave and radio frequency irradiation. More importantly, by utilising Nitrogen Vacancy centres with nearby 13C nuclei, using this interconnect, one has the potential build a quantum device where the nuclear spin qubits are connected over centimeter distances via the Nitrogen Vacancy electronic spins interacting through the superconducting bus.

  17. Polarization dependent asymmetric magneto-resistance features in nanocrystalline diamond films

    SciTech Connect (OSTI)

    Bhattacharyya, Somnath, E-mail: Somnath.Bhattacharyya@wits.ac.za [Nano-Scale Transport Physics Laboratory, School of Physics, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg (South Africa); DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg, South Africa and Department of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Churochkin, Dmitry [Nano-Scale Transport Physics Laboratory, School of Physics, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg (South Africa)

    2014-08-18

    Polar angle-dependence of magneto-resistance (AMR) in heavily nitrogen-incorporated ultra-nanocrystalline diamond (UNCD) films is recorded by applying high magnetic fields, which shows strong anisotropic features at low temperatures. The temperature-dependence of MR and AMR can reveal transport in the weak-localization regime, which is explained by using a superlattice model for arbitrary values of disorder and angles. While a propagative Fermi surface model explains the negative MR features for low degree of disorder the azimuthal angle-dependent MR shows field dependent anisotropy due to the aligned conducting channels on the layers normal to film growth direction. The analysis of MR and AMR can extract the temperature dependence of dephasing time with respect to the elastic scattering time which not only establishes quasi-two dimensional features in this system but also suggests a potential application in monitoring the performance of UNCD based quantum devices.

  18. Band-selective shaped pulse for high fidelity quantum control in diamond

    SciTech Connect (OSTI)

    Chang, Yan-Chun; Xing, Jian; Liu, Gang-Qin; Jiang, Qian-Qing; Li, Wu-Xia [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, Fei-Hao [Tsinghua National Laboratory for Information Science and Technology, Beijing 100084 (China); State Key Laboratory of Low-Dimensional Physics and Department of Physics, Tsinghua University, Beijing 100084 (China); Gu, Chang-Zhi; Pan, Xin-Yu, E-mail: xypan@aphy.iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China); Long, Gui-Lu [Tsinghua National Laboratory for Information Science and Technology, Beijing 100084 (China); State Key Laboratory of Low-Dimensional Physics and Department of Physics, Tsinghua University, Beijing 100084 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China)

    2014-06-30

    High fidelity quantum control of qubits is crucially important for realistic quantum computing, and it becomes more challenging when there are inevitable interactions between qubits. We introduce a band-selective shaped pulse, refocusing BURP (REBURP) pulse, to cope with the problems. The electron spin of nitrogen-vacancy centers in diamond is flipped with high fidelity by the REBURP pulse. In contrast with traditional rectangular pulses, the shaped pulse has almost equal excitation effect in a sharply edged region (in frequency domain). So the three sublevels of host {sup 14}N nuclear spin can be flipped accurately simultaneously, while unwanted excitations of other sublevels (e.g., of a nearby {sup 13}C nuclear spin) is well suppressed. Our scheme can be used for various applications such as quantum metrology, quantum sensing, and quantum information process.

  19. Coherent spin control of a nanocavity-enhanced qubit in diamond

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

    Li, Luozhou; Lu, Ming; Schroder, Tim; Chen, Edward H.; Walsh, Michael; Bayn, Igal; Goldstein, Jordan; Gaathon, Ophir; Trusheim, Matthew E.; Mower, Jacob; et al

    2015-01-28

    A central aim of quantum information processing is the efficient entanglement of multiple stationary quantum memories via photons. Among solid-state systems, the nitrogen-vacancy centre in diamond has emerged as an excellent optically addressable memory with second-scale electron spin coherence times. Recently, quantum entanglement and teleportation have been shown between two nitrogen-vacancy memories, but scaling to larger networks requires more efficient spin-photon interfaces such as optical resonators. Here we report such nitrogen-vacancy nanocavity systems in strong Purcell regime with optical quality factors approaching 10,000 and electron spin coherence times exceeding 200 µs using a silicon hard-mask fabrication process. This spin-photon interfacemore »is integrated with on-chip microwave striplines for coherent spin control, providing an efficient quantum memory for quantum networks.« less

  20. Broadband, noise-free optical quantum memory with neutral nitrogen-vacancy centers in diamond

    E-Print Network [OSTI]

    E. Poem; C. Weinzetl; J. Klatzow; K. T. Kaczmarek; J. H. D. Munns; T. F. M. Champion; D. J. Saunders; J. Nunn; I. A. Walmsley

    2015-04-23

    It is proposed that the ground-state manifold of the neutral nitrogen-vacancy center in diamond could be used as a quantum two-level system in a solid-state-based implementation of a broadband, noise-free quantum optical memory. The proposal is based on the same-spin $\\Lambda$-type three-level system created between the two E orbital ground states and the A$_1$ orbital excited state of the center, and the cross-linear polarization selection rules obtained with the application of transverse electric field or uniaxial stress. Possible decay and decoherence mechanisms of this system are discussed, and it is shown that high-efficiency, noise-free storage of photons as short as a few tens of picoseconds for at least a few nanoseconds could be possible at low temperature.