WorldWideScience

Sample records for diamond counters

  1. Diamond identifaction

    International Nuclear Information System (INIS)

    1976-01-01

    X-ray topography on diamonds allows for unique identification of diamonds. The method described consists of the registration of crystal defects, inclusions etc. of a diamond, resulting in a 'finger print' of the individual jewel which can only be changed by its complete destruction

  2. Needle counter

    International Nuclear Information System (INIS)

    Fujita, Yuzo

    1977-01-01

    Needle counter had been devised by Geiger about 60 years ago before the present GM counter appeared. It is suitable for the detection of weak radiation because it is limited in effective volume, if the background due to mainly cosmic ray is proportional to the effective volume of the counter. Recently the very low β detector having a needle counter as the main detector has been developed. It showed highly excellent performance in the measurements of small area samples, about ten times sensitive as compared with other detectors. The counter is installed in the very low radiation measuring well at Nokogiriyama, Chiba Prefecture, using a NaI scintillator as its guard counter. D. H. Wilkinson first treated a gas amplification counter theoretically and quantitatively. The authors have obtained good results in the comparison with the experiments of the counter using a generalized form of Wilkinson theory. The findings obtained through this study seem to be applicable to the electrode arrangement which is important for the counter design. It was found that the excellent rise time of induced pulses in a gas amplification counter was achieved in larger amplification factor and smaller convolution effect. In the detection of charged particles with small obstructing capability such as γ ray, faster rise time and higher pulses can be obtained with needle counters than wire counters. (Wakatsuki, Y.)

  3. Diamond identification

    International Nuclear Information System (INIS)

    Lang, A.R.

    1979-01-01

    Methods of producing sets of records of the internal defects of diamonds as a means of identification of the gems by x-ray topography are described. To obtain the records one can either use (a) monochromatic x-radiation reflected at the Bragg angle from crystallographically equivalent planes of the diamond lattice structure, Bragg reflections from each such plane being recorded from a number of directions of view, or (b) white x-radiation incident upon the diamond in directions having a constant angular relationship to each equivalent axis of symmetry of the diamond lattice structure, Bragg reflections being recorded for each direction of the incident x-radiation. By either method an overall point-to-point three dimensional representation of the diamond is produced. (U.K.)

  4. Diamond nanophotonics

    Directory of Open Access Journals (Sweden)

    Katja Beha

    2012-12-01

    Full Text Available We demonstrate the coupling of single color centers in diamond to plasmonic and dielectric photonic structures to realize novel nanophotonic devices. Nanometer spatial control in the creation of single color centers in diamond is achieved by implantation of nitrogen atoms through high-aspect-ratio channels in a mica mask. Enhanced broadband single-photon emission is demonstrated by coupling nitrogen–vacancy centers to plasmonic resonators, such as metallic nanoantennas. Improved photon-collection efficiency and directed emission is demonstrated by solid immersion lenses and micropillar cavities. Thereafter, the coupling of diamond nanocrystals to the guided modes of micropillar resonators is discussed along with experimental results. Finally, we present a gas-phase-doping approach to incorporate color centers based on nickel and tungsten, in situ into diamond using microwave-plasma-enhanced chemical vapor deposition. The fabrication of silicon–vacancy centers in nanodiamonds by microwave-plasma-enhanced chemical vapor deposition is discussed in addition.

  5. Diamond Fuzzy Number

    Directory of Open Access Journals (Sweden)

    T. Pathinathan

    2015-01-01

    Full Text Available In this paper we define diamond fuzzy number with the help of triangular fuzzy number. We include basic arithmetic operations like addition, subtraction of diamond fuzzy numbers with examples. We define diamond fuzzy matrix with some matrix properties. We have defined Nested diamond fuzzy number and Linked diamond fuzzy number. We have further classified Right Linked Diamond Fuzzy number and Left Linked Diamond Fuzzy number. Finally we have verified the arithmetic operations for the above mentioned types of Diamond Fuzzy Numbers.

  6. Body counter

    International Nuclear Information System (INIS)

    Koeppe, P.

    1975-01-01

    The paper gives a survey on some applications of the whole body counter in clinical practice and a critical study of its application as a routine testing method. Remarks on the necessary precautions are followed by a more detailed discussion of the determination of the natural potassium content, the iron metabolism, the vitamin B12 test, investigations of the metabolism of the bone using 47 Ca and 85 Sr, investigations with iodine and iodine-labelled substances, clearance investigations (in particular the 51 Cr EDTA clearance test), as well as the possibilities of neutron activation in vivo. (ORU/AK) [de

  7. Synthetic diamond in electrochemistry

    International Nuclear Information System (INIS)

    Pleskov, Yurii V

    1999-01-01

    The results of studies on the electrochemistry of diamond carried out during the last decade are reviewed. Methods for the preparation, the crystalline structure and the main electrophysical properties of diamond thin films are considered. Depending on the doping conditions, the diamond behaves as a superwide-gap semiconductor or as a semimetal. It is shown that the 'metal-like' diamond is corrosion-resistant and can be used advantageously as an electrode in the electrosynthesis (in particular, for the electroreduction of compounds that are difficult to reduce) and electroanalysis. Kinetic characteristics of some redox reactions and the impedance parameters for diamond electrodes are presented. The results of comparative studies of the electrodes made of diamond single crystals, polycrystalline diamond and amorphous diamond-like carbon, which reveal the effect of the crystalline structure (e.g., the influence of intercrystallite boundaries) on the electrochemical properties of diamond, are presented. The bibliography includes 99 references.

  8. Thermal and fast neutron dosimetry using artificial single crystal diamond detectors

    International Nuclear Information System (INIS)

    Angelone, M.; Pillon, M.; Prestopino, G.; Marinelli, Marco; Milani, E.; Verona, C.; Verona-Rinati, G.; Aielli, G.; Cardarelli, R.; Santonico, R.; Bedogni, R.; Esposito, A.

    2011-01-01

    In this work we propose the artificial Single Crystal Diamond (SCD) detector covered with a thin layer (0.5 μm/4 μm) of 6 LiF as a simultaneous thermal and fast neutron fluence monitor. Some interesting properties of the diamond response versus the neutron energy are evidenced thanks to Monte Carlo simulation using the MCNPX code which allows to propose the diamond detector also as an ambient dose equivalent (H∗(10)) monitor (REM counter).

  9. Diamond bio electronics.

    Science.gov (United States)

    Linares, Robert; Doering, Patrick; Linares, Bryant

    2009-01-01

    The use of diamond for advanced applications has been the dream of mankind for centuries. Until recently this dream has been realized only in the use of diamond for gemstones and abrasive applications where tons of diamonds are used on an annual basis. Diamond is the material system of choice for many applications, but its use has historically been limited due to the small size, high cost, and inconsistent (and typically poor) quality of available diamond materials until recently. The recent development of high quality, single crystal diamond crystal growth via the Chemical Vapor Deposition (CVD) process has allowed physcists and increasingly scientists in the life science area to think beyond these limitations and envision how diamond may be used in advanced applications ranging from quantum computing, to power generation and molecular imaging, and eventually even diamond nano-bots. Because of diamond's unique properties as a bio-compatible material, better understanding of diamond's quantum effects and a convergence of mass production, semiconductor-like fabrication process, diamond now promises a unique and powerful key to the realization of the bio-electronic devices being envisioned for the new era of medical science. The combination of robust in-the-body diamond based sensors, coupled with smart bio-functionalized diamond devices may lead to diamond being the platform of choice for bio-electronics. This generation of diamond based bio-electronic devices would contribute substantially to ushering in a paradigm shift for medical science, leading to vastly improved patient diagnosis, decrease of drug development costs and risks, and improved effectiveness of drug delivery and gene therapy programs through better timed and more customized solutions.

  10. Diamond semiconducting devices

    International Nuclear Information System (INIS)

    Polowczyk, M.; Klugmann, E.

    1999-01-01

    Many efforts to apply the semiconducting diamond for construction of electronic elements: resistors, thermistors, photoresistors, piezoresistors, hallotrons, pn diodes, Schottky diodes, IMPATT diodes, npn transistor, MESFETs and MISFETs are reviewed. Considering the possibilities of acceptor and donor doping, electrical resistivity and thermal conductivity of diamond as well as high electric-field breakdown points, that diamond devices could be used at about 30-times higher frequency and more then 8200 times power than silicon devices. Except that, due to high heat resistant of diamond, it is concluded that diamond devices can be used in environment at high temperature, range of 600 o C. (author)

  11. Diamonds for beam instrumentation

    International Nuclear Information System (INIS)

    Griesmayer, Erich

    2013-01-01

    Diamond is perhaps the most versatile, efficient and radiation tolerant material available for use in beam detectors with a correspondingly wide range of applications in beam instrumentation. Numerous practical applications have demonstrated and exploited the sensitivity of diamond to charged particles, photons and neutrons. In this paper, a brief description of a generic diamond detector is given and the interaction of the CVD diamond detector material with protons, electrons, photons and neutrons is presented. Latest results of the interaction of sCVD diamond with 14 MeV mono-energetic neutrons are shown.

  12. Diamond Synthesis Employing Nanoparticle Seeds

    Science.gov (United States)

    Uppireddi, Kishore (Inventor); Morell, Gerardo (Inventor); Weiner, Brad R. (Inventor)

    2014-01-01

    Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  13. Thermally stable diamond brazing

    Science.gov (United States)

    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.

  14. Distributed performance counters

    Science.gov (United States)

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  15. Tribological wear behavior of diamond reinforced composite coating

    International Nuclear Information System (INIS)

    Venkateswarlu, K.; Ray, Ajoy Kumar; Gunjan, Manoj Kumar; Mondal, D.P.; Pathak, L.C.

    2006-01-01

    In the present study, diamond reinforced composite (DRC) coating has been applied on mild steel substrate using thermal spray coating technique. The composite powder consists of diamond, tungsten carbide, and bronze, which was mixed in a ball mill prior deposition by thermal spray. The microstructure and the distribution of diamond and tungsten carbide particle in the bronze matrix were studied. The DRC-coated mild steel substrates were assessed in terms of their high stress abrasive wear and compared with that of uncoated mild steel substrates. It was observed that when sliding against steel, the DRC-coated sample initially gains weight, but then loses the transferred counter surface material. In case of abrasive wear, the wear rate was greatly reduced due to the coating; wherein the wear rate decreased with increase in diamond content

  16. Detection of diamonds

    International Nuclear Information System (INIS)

    Hansen, J.O.; Blondeel, E.J.G.; Taylor, G.T.

    1991-01-01

    Diamond particles are distinguished from non-diamond, associated particles on the basis of their higher refractive index. The particles are brought to a specific location, typically in a stream of water flowing full in a vertical duct, and a beam of collimated electromagnetic radiation is directed at them. An array of radiation detectors is provided to detect refracted and/or reflected radiation. The array is so configured that the responses of the detectors, considered collectively, will be indicative of the presence of a diamond when a diamond is in fact present. However, when a particle having a substantially lower refractive index is present, the responses of the detectors will not be so indicative. The diamond and non-diamond particles can subsequently be sorted from one another

  17. Cerenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Etkin, A.; Kostoulas, I.; Leith, D.W.G.S.; Thun, R.

    1977-01-01

    The Cherenkov counter described for use at Isabelle is a threshold counter in which light is focussed on phototubes. The counter is applicable in large-angle, small-aperture magnetic spectrometers for measurement of particle yields at large p/sub T/. Three of these counters will provide complete π-K-p separation in the range of 7-20 GeV/c. Other Cherenkov counters are discussed and a bibliography of relevant literature on the counters utilizing photoionization is included

  18. Diamond-cleaning investigations

    International Nuclear Information System (INIS)

    Derry, T.E.

    Four parcels of diamonds which either had or had not been cleaned using the usual techniques, chiefly involving etch in molten potassium nitrate were supplied by De Beers Diamond Research Laboratories. Each parcel contained about 40 stones, amounting to about 10 carats. Half the diamonds in each parcel were cleaned by a standard procedure involving half an hours ultrasonic agitation in a 20% solution of the commercial detergent 'Contrad' which is effectively a surfactant and chelating agent. Visual comparisons by a number of observers who were not told the stones' histories, established that these diamonds generally had a more sparkling appearance after the cleaning procedure had been applied

  19. Optical engineering of diamond

    CERN Document Server

    Rabeau, James R

    2013-01-01

    This is the first comprehensive book on the engineering of diamond optical devices. It will give readers an up-to-date account of the properties of optical quality synthetic diamond (single crystal, nanodiamond and polycrystalline) and reviews the large and growing field of engineering of diamond-based optical devices, with applications in quantum computation, nano-imaging, high performance lasers, and biomedicine. It aims to provide scientists, engineers and physicists with a valuable resource and reference book for the design and performance of diamond-based optical devices.

  20. CEDAR counter (internal part)

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    Here on the mounting bench. The counter is a differential Cerenkov, corrected for chromaticity, able to differentiate pions from kaons up to 350 GeV. Counters of this type were used in all SPS hadron beams.

  1. Whole Body Counters (rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Woodburn, John H. [Walter Johnson High School, Rockville, MD; Lengemann, Frederick W. [Cornell University

    1967-01-01

    Whole body counters are radiation detecting and measuring instruments that provide information about the human body. This booklet describes different whole body counters, scientific principles that are applied to their design, and ways they are used.

  2. Diamond Nucleation Using Polyethene

    Science.gov (United States)

    Morell, Gerardo (Inventor); Makarov, Vladimir (Inventor); Varshney, Deepak (Inventor); Weiner, Brad (Inventor)

    2013-01-01

    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.

  3. Diamond films: Historical perspective

    Energy Technology Data Exchange (ETDEWEB)

    Messier, R. [Pennsylvania State Univ., University Park (United States)

    1993-01-01

    This section is a compilation of notes and published international articles about the development of methods of depositing diamond films. Vapor deposition articles are included from American, Russian, and Japanese publications. The international competition to develop new deposition methodologies is stressed. The current status of chemical vapor deposition of diamond is assessed.

  4. Diamond Pixel Detectors

    International Nuclear Information System (INIS)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Doroshenko, J.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foster, J.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Gobbi, B.; Grim, G.P.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Lander, R.; Logiudice, A.; Lu, R.; Lynne, L.M.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Perera, L.; Pirollo, S.; Plano, R.; Procario, M.; Riester, J.L.; Roe, S.; Rott, C.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Wedenig, R.; Weilhammer, P.; White, C.; Zeuner, W.; Zoeller, M.

    2001-01-01

    Diamond based pixel detectors are a promising radiation-hard technology for use at the LHC. We present first results on a CMS diamond pixel sensor. With a threshold setting of 2000 electrons, an average pixel efficiency of 78% was obtained for normally incident minimum ionizing particles

  5. Diamond Pixel Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Doroshenko, J.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foster, J.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Gobbi, B.; Grim, G.P.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Lander, R.; Logiudice, A.; Lu, R.; Lynne, L.M.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Perera, L. E-mail: perera@physics.rutgers.edu; Pirollo, S.; Plano, R.; Procario, M.; Riester, J.L.; Roe, S.; Rott, C.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Wedenig, R.; Weilhammer, P.; White, C.; Zeuner, W.; Zoeller, M

    2001-06-01

    Diamond based pixel detectors are a promising radiation-hard technology for use at the LHC. We present first results on a CMS diamond pixel sensor. With a threshold setting of 2000 electrons, an average pixel efficiency of 78% was obtained for normally incident minimum ionizing particles.

  6. Investing in Diamonds

    NARCIS (Netherlands)

    Renneboog, Luc

    2015-01-01

    This paper examines the risk-return characteristics of investment grade gems (white diamonds, colored diamonds and other types of gems including sapphires, rubies, and emeralds). The transactions are coming from gem auctions and span the period 1999-2012. Over our time frame, the annual nominal USD

  7. Neutron Detection at JET Using Artificial Diamond Detectors

    International Nuclear Information System (INIS)

    Pillon, M.; Angelone, M.; Lattanzi, D.; Milani, E.; Tucciarone, A.; Verona-Rinati, G.; Popovichev, S.; Murari, A.

    2006-01-01

    Three CVD diamond detectors are installed and operated at Joint European Torus, Culham laboratory. Diamond detectors are very promising detectors to be used in fusion environment due to their radiation hardness, gamma discrimination properties, fast response and spectroscopy properties. The aim of this work is to test and qualify artificial diamond detectors as neutron counters and spectrometers on a large fusion device. Two of these detectors are polycrystalline CVD diamond films of thickness 30 mm and 40 mm respectively while the third detector is a monocrystalline CVD of 110 mm thickness. The first polycrystalline diamond is covered with 4 mm of LiF 95 % enriched in 6 Li and enclosed inside a polyethylene moderator cap. This detector is used with a standard electronic chain made with a charge preamplifier, shaping amplifier and threshold discriminator. It is used to measure the time-dependent total neutron yield produced by JET plasma and its signal is compared with JET fission chambers. The second polycrystalline diamond is connected with a fast (1 GHz) preamplifier and a threshold discriminator via a long (about 100 m) double screened cable. This detector is used to detect the 14 MeV neutrons produced by triton burn-up using the reaction 12 C (n, α) 9 Be which occurs in diamond and a proper discriminator threshold. The response of this detector is fast and the electronic is far from the high radiation environment. Its signal is used in comparison with JET silicon diodes. The third monocrystalline diamond is also connected using a standard electronic and is used to demonstrate the feasibility of 14 MeV neutron spectrometry at about 3% peak resolution taking advantage of the spectrometer properties of monocrystalline diamonds. The results obtained are presented in this work. (author)

  8. Friction and wear properties of diamonds and diamond coatings

    International Nuclear Information System (INIS)

    Hayward, I.P.

    1991-01-01

    The recent development of chemical vapor deposition techniques for diamond growth enables bearings to be designed which exploit diamond's low friction and extreme resistance to wear. However, currently produced diamond coatings differ from natural diamond surfaces in that they are polycrystalline and faceted, and often contain appreciable amounts of non-diamond material (i.e. graphitic or amorphous carbon). Roughness, in particular, influences the friction and wear properties; rough coatings severely abrade softer materials, and can even wear natural diamond sliders. Nevertheless, the best available coatings exhibit friction coefficients as low as those of natural diamond and are highly resistant to wear. This paper reviews the tribological properties of natural diamond, and compares them with those of chemical vapor deposited diamond coatings. Emphasis is placed on the roles played by roughness and material transfer in controlling frictional behavior. (orig.)

  9. Multimode pulse counter

    International Nuclear Information System (INIS)

    Natanzon, D.D.

    1982-01-01

    A pulse counter with code conversion is described. The counter is based on the integrated circuits of direct-counting devices of medium integration. The counter ensures various modes of pulse counting depending on the logical control signals: reversible, two-channel summing, one-channel summing binary, summing with ''storage'' signal code fixation without interrupting pulse counting. Arrangement of the suggested structure as a microcircuit of medium integration might contribute to reduction in the counter type nomenclature in digital families of widely used integrated circuits

  10. Functionalized diamond nanoparticles

    KAUST Repository

    Beaujuge, Pierre M.; El Tall, Omar; Raja, Inam U.

    2014-01-01

    A diamond nanoparticle can be functionalized with a substituted dienophile under ambient conditions, and in the absence of catalysts or additional reagents. The functionalization is thought to proceed through an addition reaction.

  11. Functionalized diamond nanoparticles

    KAUST Repository

    Beaujuge, Pierre M.

    2014-10-21

    A diamond nanoparticle can be functionalized with a substituted dienophile under ambient conditions, and in the absence of catalysts or additional reagents. The functionalization is thought to proceed through an addition reaction.

  12. Diamond Jubilee Meeting

    Indian Academy of Sciences (India)

    1994-10-01

    Oct 1, 1994 ... Science, Bangalore, the Diamond Jubilee Annual. Meeting will be held in ... "The fascination of statistics" .... on post Hartree-Fock methods, highly correlated systems ..... Gold Medal of the National Institute of Social. Sciences ...

  13. Quantum Computing in Diamond

    National Research Council Canada - National Science Library

    Prawer, Steven

    2007-01-01

    The aim of this proposal is to demonstrate the key elements needed to construct a logical qubit in diamond by exploiting the remarkable quantum properties of the nitrogen-vacancy (NV) optical centre...

  14. The first CEDAR counter

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The first differential Cerenkov counter with chromatic corrections (called CEDAR) successfully tested at the PS in July 75. These counters were used in the SPS hadronic beams for particle identification. Some of the eight photomultipliers can be seen: they receive the light reflected back through the annular diaphragm. René Maleyran stands on the left.

  15. Diamond anvil cells using boron-doped diamond electrodes covered with undoped diamond insulating layer

    Science.gov (United States)

    Matsumoto, Ryo; Yamashita, Aichi; Hara, Hiroshi; Irifune, Tetsuo; Adachi, Shintaro; Takeya, Hiroyuki; Takano, Yoshihiko

    2018-05-01

    Diamond anvil cells using boron-doped metallic diamond electrodes covered with undoped diamond insulating layers have been developed for electrical transport measurements under high pressure. These designed diamonds were grown on a bottom diamond anvil via a nanofabrication process combining microwave plasma-assisted chemical vapor deposition and electron beam lithography. The resistance measurements of a high-quality FeSe superconducting single crystal under high pressure were successfully demonstrated by just putting the sample and gasket on the bottom diamond anvil directly. The superconducting transition temperature of the FeSe single crystal was increased to up to 43 K by applying uniaxial-like pressure.

  16. Diamond pixel modules

    International Nuclear Information System (INIS)

    Asner, D.; Barbero, M.; Bellini, V.; Belyaev, V.; Brom, J-M.; Bruzzi, M.; Chren, D.; Cindro, V.; Claus, G.; Cristinziani, M.; Costa, S.; D'Alessandro, R.; Boer, W. de; Dobos, D.; Dolenc, I.; Dulinski, W.; Duris, J.; Eremin, V.; Eusebi, R.; Frais-Koelbl, H.

    2011-01-01

    With the commissioning of the LHC in 2010 and upgrades expected in 2015, ATLAS and CMS are planning to upgrade their innermost tracking layers with radiation hard technologies. Chemical Vapor Deposition diamond has been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle, CDF and all LHC experiments. This material is now being considered as a sensor material for use very close to the interaction region where the most extreme radiation conditions exist. Recently the RD42 collaboration constructed, irradiated and tested polycrystalline and single-crystal chemical vapor deposition diamond sensors to the highest fluences expected at the super-LHC. We present beam test results of chemical vapor deposition diamond up to fluences of 1.8x10 16 protons/cm 2 illustrating that both polycrystalline and single-crystal chemical vapor deposition diamonds follow a single damage curve. We also present beam test results of irradiated complete diamond pixel modules.

  17. Diamond pixel modules

    Energy Technology Data Exchange (ETDEWEB)

    Asner, D. [Carleton University, Ottawa (Canada); Barbero, M. [Universitaet Bonn (Germany); Bellini, V. [INFN/University of Catania (Italy); Belyaev, V. [MEPHI Institute, Moscow (Russian Federation); Brom, J-M. [IPHC, Strasbourg (France); Bruzzi, M. [INFN/University of Florence (Italy); Chren, D. [Czech Technical University, Prague (Czech Republic); Cindro, V. [Jozef Stefan Institute, Ljubljana (Slovenia); Claus, G. [IPHC, Strasbourg (France); Cristinziani, M. [Universitaet Bonn (Germany); Costa, S. [INFN/University of Catania (Italy); D' Alessandro, R. [Department of Energetics/INFN Florence (Italy); Boer, W. de [Universitaet Karlsruhe, Karlsruhe (Germany); Dobos, D. [CERN, Geneva (Switzerland); Dolenc, I. [Jozef Stefan Institute, Ljubljana (Slovenia); Dulinski, W. [IPHC, Strasbourg (France); Duris, J. [UCLA, Los Angeles, CA (United States); Eremin, V. [Ioffe Institute, St. Petersburg (Russian Federation); Eusebi, R. [FNAL, Batavia (United States); Frais-Koelbl, H. [Fachhochschule fuer Wirtschaft und Technik, Wiener Neustadt (Austria)

    2011-04-21

    With the commissioning of the LHC in 2010 and upgrades expected in 2015, ATLAS and CMS are planning to upgrade their innermost tracking layers with radiation hard technologies. Chemical Vapor Deposition diamond has been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle, CDF and all LHC experiments. This material is now being considered as a sensor material for use very close to the interaction region where the most extreme radiation conditions exist. Recently the RD42 collaboration constructed, irradiated and tested polycrystalline and single-crystal chemical vapor deposition diamond sensors to the highest fluences expected at the super-LHC. We present beam test results of chemical vapor deposition diamond up to fluences of 1.8x10{sup 16} protons/cm{sup 2} illustrating that both polycrystalline and single-crystal chemical vapor deposition diamonds follow a single damage curve. We also present beam test results of irradiated complete diamond pixel modules.

  18. Ion implantation into diamond

    International Nuclear Information System (INIS)

    Sato, Susumu

    1994-01-01

    The graphitization and the change to amorphous state of diamond surface layer by ion implantation and its characteristics are reported. In the diamond surface, into which more than 10 16 ions/cm 2 was implanted, the diamond crystals are broken, and the structure changes to other carbon structure such as amorphous state or graphite. Accompanying this change of structure, the electric conductivity of the implanted layer shows two discontinuous values due to high resistance and low resistance. This control of structure can be done by the temperature of the base during the ion implantation into diamond. Also it is referred to that by the base temperature during implantation, the mutual change of the structure between amorphous state and graphite can be controlled. The change of the electric resistance and the optical characteristics by the ion implantation into diamond surface, the structural analysis by Raman spectroscopy, and the control of the structure of the implanted layer by the base temperature during implantation are reported. (K.I.)

  19. Nanocrystalline diamond coatings for machining

    Energy Technology Data Exchange (ETDEWEB)

    Frank, M.; Breidt, D.; Cremer, R. [CemeCon AG, Wuerselen (Germany)

    2007-07-01

    This history of CVD diamond synthesis goes back to the fifties of the last century. However, the scientific and economical potential was only gradually recognized. In the eighties, intensive worldwide research on CVD diamond synthesis and applications was launched. Industrial products, especially diamond-coated cutting tools, were introduced to the market in the middle of the nineties. This article shows the latest developments in this area, which comprises nanocrystalline diamond coating structures. (orig.)

  20. Counter-cryptanalysis

    NARCIS (Netherlands)

    M.M.J. Stevens (Marc); R. Canetti; J.A. Garay

    2013-01-01

    textabstractWe introduce \\emph{counter-cryptanalysis} as a new paradigm for strengthening weak cryptographic primitives against cryptanalytic attacks. Redesigning a weak primitive to more strongly resist cryptanalytic techniques will unavoidably break backwards compatibility. Instead,

  1. A Neutron Rem Counter

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, I Oe; Braun, J

    1964-01-15

    A neutron detector is described which measures the neutron dose rate in rem/h independently of the energy of the neutrons from thermal to 15 MeV. The detector consists of a BF{sub 3} proportional counter surrounded by a shield made of polyethylene and boron plastic that gives the appropriate amount of moderation and absorption to the impinging neutrons to obtain rem response. Two different versions have been developed. One model can utilize standard BF{sub 3} counters and is suitable for use in installed monitors around reactors and accelerators and the other model is specially designed for use in a portable survey instrument. The neutron rem counter for portable instruments has a sensitivity of 2.4 cps/mrem/h and is essentially nondirectional in response. With correct bias setting the counter is insensitive to gamma exposure up to 200 r/h from Co-60.

  2. Biofunctionalization of diamond microelectrodes

    Energy Technology Data Exchange (ETDEWEB)

    Reitinger, Andreas Adam; Lud, Simon Quartus; Stutzmann, Martin; Garrido, Jose Antonio [Walter Schottky Institut, TU Muenchen (Germany); Hutter, Naima Aurelia; Richter, Gerhard; Jordan, Rainer [WACKER-Chair of Macromolecular Chemistry, TU Muenchen (Germany)

    2010-07-01

    In this work we present two main routes for the biofunctionalization of nanocrystalline diamond films, aiming at the application of diamond microelectrodes as amperometric biosensors. We report on direct covalent grafting of biomolecules on nanocrystalline diamond films via diazonium monophenyls and biphenyls as well as other linker molecules, forming self-assembled monolayers on the diamond surface. Monolayers with different functional head groups have been characterized. Patterning of the available functional groups using electron beam-induced chemical lithography allows the selective preparation of well-localized docking sites for the immobilization of biomolecules. Furthermore, polymer brushes are expected to enable novel paths for designing more advanced biosensing schemes, incorporating multifunctional groups and a higher loading capacity for biomolecules. Here, we focus on the preparation of polymer grafts by self-initiated photografting and photopolymerization. Further chemical modification of the grafted polymer brushes results in the introduction of additional functional molecules, paving the way for the incorporation of more complex molecular structures such as proteins. In a comparative study we investigate the advantages and disadvantages of both approaches.

  3. CVD diamond - fundamental phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Yarbrough, W.A. [Pennsylvania State Univ., University Park (United States)

    1993-01-01

    This compilation of figures and diagrams addresses the basic physical processes involved in the chemical vapor deposition of diamond. Different methods of deposition are illustrated. For each method, observations are made of the prominent advantages and disadvantages of the technique. Chemical mechanisms of nucleation are introduced.

  4. Nuclear timer/counter

    International Nuclear Information System (INIS)

    Wuthayavanich, S.

    1978-01-01

    This thesis represents the development of a Timer/COUNTER compatible to the standard Nuclear Instrument Module Specifications. The unit exhibits high accuracy, light weight and ease of maintenance. The unit also has a built-in precision discriminator to discriminate unwanted signals that may cause interference in counting. With line frequency time base the timer can be preset in steps from 0.1 sec. to 9 x 10 5 min. The counter with six digits miniature display and an overflow output has a maximum counting rate of 10 MHz. The accumulated counting data can be transferred to a teletype or printer for hard copy printout with the aid of ORTEC 777 Line Printer or 432 A Print-out Control or any print out interface with input compatible to the print output of the Timer/Counter. Owing to its NIM compatibility the unit is directly powered by the NIM power supply

  5. Structure and properties of diamond and diamond-like films

    Energy Technology Data Exchange (ETDEWEB)

    Clausing, R.E. [Oak Ridge National Lab., TN (United States)

    1993-01-01

    This section is broken into four parts: (1) introduction, (2) natural IIa diamond, (3) importance of structure and composition, and (4) control of structure and properties. Conclusions of this discussion are that properties of chemical vapor deposited diamond films can compare favorably with natural diamond, that properties are anisotropic and are a strong function of structure and crystal perfection, that crystal perfection and morphology are functions of growth conditions and can be controlled, and that the manipulation of texture and thereby surface morphology and internal crystal perfection is an important step in optimizing chemically deposited diamond films for applications.

  6. An efficient anticoincidence counter

    CERN Multimedia

    1977-01-01

    This scintillation counter (about 25 cm diameter) was prepared at CERN for an experiment at the Saclay 600 MeV electron linac studying molecular processes originated in liquid hydrogen by muons. The counter is meant to surround the target and detect charged particles emerging from the hydrogen. The experiment was a CERN-Saclay collaboration which used the linac so as to take advantage of the time structure of the electron beam(see CERN Courier Sep 1977 and J. Bardin et al. Phys. Lett. B104 (1981) 320)

  7. EXAFS measurements under high pressure conditions using a combination of a diamond anvil cell and synchrotron radiation

    International Nuclear Information System (INIS)

    Sueno, Shigeho; Nakai, Izumi; Imafuku, Masayuki; Morikawa, Hideki; Kimata, Mitsuyoshi; Ohsumi, Kazumasa; Nomura, Masaharu; Shimomura, Osamu.

    1986-01-01

    EXAFS spectra for Fe, Co, Ni K-edges were successfully measured under high pressure conditions using a combination of a set of normal 1/8 carat diamond anvils, synchrotron radiation and a scintillation counter. A newly developed motor controlled goniometer stage was used for adjusting the position of a miniature diamond anvil cell. On the measurement of Cr and Mn spectra, specially designed thinner diamond anvil was necessary. EXAFS analysis of bis(dimethylglyoximato)nickel(II) at pressures from 1 atm to 5.6 GPa was made. (author)

  8. Genetics Home Reference: Diamond-Blackfan anemia

    Science.gov (United States)

    ... Home Health Conditions Diamond-Blackfan anemia Diamond-Blackfan anemia Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Diamond-Blackfan anemia is a disorder of the bone marrow . The ...

  9. Diamond turning of glass

    Energy Technology Data Exchange (ETDEWEB)

    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

  10. Fast diamond photoconductors

    International Nuclear Information System (INIS)

    Pochet, T.

    1993-01-01

    Preliminary results on the response of type Ib and IIa diamond photodetectors to fast laser pulse exposures at 265 and 530 nm are presented. The influence of the applied bias, the laser wavelengths and the light intensity on the detector sensitivity is studied. Also, recent measurements with 1.25 MeV gamma ray pulses are reported. (authors). 13 refs., 7 figs., 1 tab

  11. Irradiated fuel bundle counter

    International Nuclear Information System (INIS)

    Campbell, J.W.; Todd, J.L.

    1975-01-01

    The design of a prototype safeguards instrument for determining the number of irradiated fuel assemblies leaving an on-power refueled reactor is described. Design details include radiation detection techniques, data processing and display, unattended operation capabilities and data security methods. Development and operating history of the bundle counter is reported. (U.S.)

  12. Irradiated fuel bundle counter

    International Nuclear Information System (INIS)

    Campbell, J.W.; Todd, J.L.

    1975-01-01

    The design of a prototype safeguards instrument for determining the number of irradiated fuel assemblies leaving an on-power refueled reactor is described. Design details include radiation detection techniques, data processing and display, unattended operation capabilities and data security methods. Development and operating history of the bundle counter is reported

  13. Counter radicalization development assistance

    OpenAIRE

    van Hippel, Karin

    2006-01-01

    The paper reviews current research and practice and recommends strategies for development agencies working in the Arab and Muslim world. It builds on the basic assumption that the realization of the Millennium Development Goals will be vital to reduce support for terrorism in the long term. Within this overall framework, emphasis is placed on particular programs that could be specifically applied to counter radicalization.

  14. Whole-body counter

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, G A; Kosterev, V V

    1975-01-24

    A counter for detecting radiation of a man (CRM) is described, which consists of two measuring converters and a recording device. In order to obtain data on spatial distribution of a gamma-radiating nuclide studied, a fixed collimator and a mobile coder made of separate slit elements are placed between the measuring converters and an object investigated.

  15. Electromagnetically Operated Counter

    Science.gov (United States)

    Goldberg, H D; Goldberg, M I

    1951-12-18

    An electromagnetically operated counter wherein signals to be counted are applied to cause stepwise rotation of a rotatable element which is connected to a suitable register. The mechanism involved consists of a rotatable armature having three spaced cores of magnetic material and a pair of diametrically opposed electromagnets with a suitable pulsing circuit to actuate the magnets.

  16. Microchip Coulter particle counter

    DEFF Research Database (Denmark)

    Larsen, Ulrik Darling; Blankenstein, Gert; Branebjerg, J.

    1997-01-01

    This paper presents a micro device employing the Coulter principle for counting and sizing of living cells and particles in liquid suspension. The microchip Coulter particle counter (μCPC) has been employed in a planar silicon structure covered with glass, which enables detailed observation during...

  17. Ion channelling in diamond

    International Nuclear Information System (INIS)

    Derry, T.E.

    1978-06-01

    Diamond is one of the most extreme cases from a channelling point of view, having the smallest thermal vibration amplitude and the lowest atomic number of commonly-encountered crystals. These are the two parameters most important for determining channelling behaviour. It is of consiberable interest therefore to see how well the theories explaining and predicting the channeling properties of other substance, succeed with diamond. Natural diamond, although the best available form for these experiments, is rather variable in its physical properties. Part of the project was devoted to considering and solving the problem of obtaining reproducible results representative of the ideal crystal. Channelling studies were performed on several good crystals, using the Rutherford backscattering method. Critical angles for proton channelling were measured for incident energies from 0.6 to 4.5 MeV, in the three most open axes and three most open planes of the diamond structure, and for α-particle channelling at 0.7 and 1.0 MeV (He + ) in the same axes and planes. For 1.0 MeV protons, the crystal temperature was varied from 20 degrees Celsius to 700 degrees Celsius. The results are presented as curves of backscattered yield versus angle in the region of each axis or plane, and summarised in the form of tables and graphs. Generally the critical angles, axial minimum yields, and temperature dependence are well predicted by the accepted theories. The most valuable overall conclusion is that the mean thermal vibration amplitude of the atoms in a crytical determines the critical approach distance to the channel walls at which an ion can remain channelled, even when this distance is much smaller than the Thomas-Fermi screening distance of the atomic potential, as is the case in diamond. A brief study was made of the radiation damage caused by α-particle bombardment, via its effect on the channelling phenomenon. It was possible to hold damage down to negligible levels during the

  18. Diamond Pixel Detectors and 3D Diamond Devices

    International Nuclear Information System (INIS)

    Venturi, N.

    2016-01-01

    Results from detectors of poly-crystalline chemical vapour deposited (pCVD) diamond are presented. These include the first analysis of data of the ATLAS Diamond Beam Monitor (DBM). The DBM module consists of pCVD diamond sensors instrumented with pixellated FE-I4 front-end electronics. Six diamond telescopes, each with three modules, are placed symmetrically around the ATLAS interaction point. The DBM tracking capabilities allow it to discriminate between particles coming from the interaction point and background particles passing through the ATLAS detector. Also, analysis of test beam data of pCVD DBM modules are presented. A new low threshold tuning algorithm based on noise occupancy was developed which increases the DBM module signal to noise ratio significantly. Finally first results from prototypes of a novel detector using pCVD diamond and resistive electrodes in the bulk, forming a 3D diamond device, are discussed. 3D devices based on pCVD diamond were successfully tested with test beams at CERN. The measured charge is compared to that of a strip detector mounted on the same pCVD diamond showing that the 3D device collects significantly more charge than the planar device.

  19. Proportional counter end effects eliminator

    International Nuclear Information System (INIS)

    Meekins, J.F.

    1976-01-01

    An improved gas-filled proportional counter which includes a resistor network connected between the anode and cathode at the ends of the counter in order to eliminate ''end effects'' is described. 3 Claims, 2 Drawing Figures

  20. Over-the-Counter Medicines

    Science.gov (United States)

    Over-the-counter (OTC) medicines are drugs you can buy without a prescription. Some OTC medicines relieve aches, pains and itches. ... medicine is safe enough to sell over-the-counter. Taking OTC medicines still has risks. Some interact ...

  1. Surface temperature measurements of diamond

    CSIR Research Space (South Africa)

    Masina, BN

    2006-07-01

    Full Text Available Diamond has the highest thermal conductivity among known materials, and as such finds uses as an industrial tool in areas where dissipation of excess heat is a requirement. In this investigation we set up a laser system to heat a diamond sample...

  2. Electrochemical applications of CVD diamond

    International Nuclear Information System (INIS)

    Pastor-Moreno, Gustavo

    2002-01-01

    Diamond technology has claimed an important role in industry since non-expensive methods of synthesis such as chemical vapour deposition allow to elaborate cheap polycrystalline diamond. This fact has increased the interest in the scientific community due to the outstanding properties of diamond. Since Pleskov published in 1987 the first paper in electrochemistry, many researchers around the world have studied different aspects of diamond electrochemistry such as reactivity, electrical structure, etc. As part of this worldwide interest these studies reveal new information about diamond electrodes. These studies report investigation of diamond electrodes characterized using structural techniques like scanning electrode microscopy and Raman spectroscopy. A new electrochemical theory based on surface states is presented that explains the metal and the semiconductor behaviour in terms of the doping level of the diamond electrode. In an effort to characterise the properties of diamond electrodes the band edges for hydrogen and oxygen terminated surface are located in organic solvent, hence avoiding possible interference that are present in aqueous solution. The determination of the band edges is performed by Mott-Schottky studies. These allow the calculation of the flat band potential and therefore the band edges. Additional cyclic voltammetric studies are presented for both types of surface termination. Mott-Schottky data and cyclic voltammograms are compared and explained in terms of the band edge localisation. Non-degenerately p-type semiconductor behaviour is presented for hydrogen terminated boron doped diamond. Graphitic surface states on oxidised surface boron doped diamond are responsible for the electrochemistry of redox couples that posses similar energy. Using the simple redox couple 1,4-benzoquinone effect of surface termination on the chemical behaviour of diamond is presented. Hydrogen sublayers in diamond electrodes seem to play an important role for the

  3. Miniaturized radiation detector with custom synthesized diamond crystal as sensor

    International Nuclear Information System (INIS)

    Grobbelaar, J.H.; Burns, R.C.; Nam, T.L.; Keddy, R.J.

    1991-01-01

    A miniaturized detector consisting of three custom built hybrid circuits, a counter and a miniature high voltage power supply was designed to operate with custom synthesized Type Ib diamond crystals as sensors. Thick-film technology was incorporated in the circuit design. With a crystal having a volume of approximately 10 mm 3 and containing approximately 60 ppm paramagnetic nitrogen, the detector was capable of measuring γ-ray dose-rates as low as 7.5 μ Gy h -1 . The response characteristic was linear up to 1 cGy h -1 . (orig.)

  4. Fundamentals of gas counters

    International Nuclear Information System (INIS)

    Bateman, J.E.

    1994-01-01

    The operation of gas counters used for detecting radiation is explained in terms of the four fundamental physical processes which govern their operation. These are 1) conversion of neutral radiation into charged particles, 2) ionization of the host gas by a fast charge particle 3) transport of the gas ions to the electrodes and 4) amplification of the electrons in a region of enhanced electric field. Practical implications of these are illustrated. (UK)

  5. Diamond lattice Heisenberg antiferromagnet

    Science.gov (United States)

    Oitmaa, J.

    2018-04-01

    We investigate ground-state and high-temperature properties of the nearest-neighbour Heisenberg antiferromagnet on the three-dimensional diamond lattice, using series expansion methods. The ground-state energy and magnetization, as well as the magnon spectrum, are calculated and found to be in good agreement with first-order spin-wave theory, with a quantum renormalization factor of about 1.13. High-temperature series are derived for the free energy, and physical and staggered susceptibilities for spin S  =  1/2, 1 and 3/2, and analysed to obtain the corresponding Curie and Néel temperatures.

  6. Presolar Diamond in Meteorites

    OpenAIRE

    Amari, Sachiko

    2009-01-01

    Presolar diamond, the carrier of the isotopically anomalous Xe component Xe-HL, was the first mineral type of presolar dust that was isolated from meteorites. The excesses in the light, p-process only isotopes 124Xe and 126Xe, and in the heavy, r-process only isotopes 134Xe and 136Xe relative to the solar ratios indicate that Xe-HL was produced in supernovae: they are the only stellar source where these two processes are believed to take place. Although these processes occur in supernovae, th...

  7. Transmission diamond imaging detector

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, John, E-mail: smedley@bnl.gov; Pinelli, Don; Gaoweia, Mengjia [Brookhaven National Laboratory, Upton, NY (United States); Muller, Erik; Ding, Wenxiang; Zhou, Tianyi [Stony Brook University, Stony Brook, NY (United States); Bohon, Jen [Case Center for Synchrotron Biosciences, Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH (United States)

    2016-07-27

    Many modern synchrotron techniques are trending toward use of high flux beams and/or beams which require enhanced stability and precise understanding of beam position and intensity from the front end of the beamline all the way to the sample. For high flux beams, major challenges include heat load management in optics (including the vacuum windows) and a mechanism of real-time volumetric measurement of beam properties such as flux, position, and morphology. For beam stability in these environments, feedback from such measurements directly to control systems for optical elements or to sample positioning stages would be invaluable. To address these challenges, we are developing diamond-based instrumented vacuum windows with integrated volumetric x-ray intensity, beam profile and beam-position monitoring capabilities. A 50 µm thick single crystal diamond has been lithographically patterned to produce 60 µm pixels, creating a >1kilopixel free-standing transmission imaging detector. This device, coupled with a custom, FPGA-based readout, has been used to image both white and monochromatic x-ray beams and capture the last x-ray photons at the National Synchrotron Light Source (NSLS). This technology will form the basis for the instrumented end-station window of the x-ray footprinting beamline (XFP) at NSLS-II.

  8. Diamonds in the Sky

    Science.gov (United States)

    Brotherton, M.

    2004-12-01

    My first science fiction novel, Star Dragon, just recently available in paperback from Tor, features a voyage to the cataclysmic variable star system SS Cygni. My second novel, Spider Star, to appear early in 2006, takes place in and around a dark matter ``planet'' orbiting a neutron star. Both novels are ``hard'' science fiction, relying on accurate physics to inform the tales. It's possible to bring to life abstract concepts like special relativity, and alien environments like accretion disks, by using science fiction. Novels are difficult to use in a science class, but short stories offer intriguing possibilities. I'm planning to edit an anthology of hard science fiction stories that contain accurate science and emphasize fundamental ideas in modern astronomy. The working title is Diamonds in the Sky. The collection will be a mix of original stories and reprints, highlighting challenging concepts covered in a typical introductory astronomy course. Larry Niven's classic story, ``Neutron Star," is an excellent demonstration of extreme tidal forces in an astronomical context. Diamonds in the Sky will include forewards and afterwards to the stories, including discussion questions and mathematical formulas/examples as appropriate. I envision this project will be published electronically or through a print-on-demand publisher, providing long-term availabilty and keeping low cost. I encourage interested parties to suggest previously published stories, or to suggest which topics must be included.

  9. Thermal applications of low-pressure diamond

    International Nuclear Information System (INIS)

    Haubner, R.; Lux, B.

    1997-01-01

    During the last decade several applications of low-pressure diamond were developed. Main products are diamond heat-spreaders using its high thermal conductivity, diamond windows with their high transparency over a wide range of wavelengths and wear resistant tool coatings because of diamonds superhardness. A short description of the most efficient diamond deposition methods (microwave, DC-glow discharge, plasma-jet and arc discharge) is given. The production and applications of diamond layers with high thermal conductivity will be described. Problems of reproducibility of diamond deposition, the influence of impurities, the heat conductivity in electronic packages, reliability and economical mass production will be discussed. (author)

  10. Investigation of the physics of diamond MEMS : diamond allotrope lithography

    International Nuclear Information System (INIS)

    Zalizniak, I.; Olivero, P.; Jamieson, D.N.; Prawer, S.; Reichart, P.; Rubanov, S.; Petriconi, S.

    2005-01-01

    We propose a novel lithography process in which ion induced phase transfomations of diamond form sacrificial layers allowing the fabrication of small structures including micro-electromechanical systems (MEMS). We have applied this novel lithography to the fabrication of diamond microcavities, cantilevers and optical waveguides. In this paper we present preliminary experiments directed at the fabrication of suspended diamond disks that have the potential for operation as optical resonators. Such structures would be very durable and resistant to chemical attack with potential applications as novel sensors for extreme environments or high temperature radiation detectors. (author). 3 refs., 3 figs

  11. Diamond: a material for acoustic devices

    OpenAIRE

    MORTET, Vincent; WILLIAMS, Oliver; HAENEN, Ken

    2008-01-01

    Diamond has been foreseen to replace silicon for high power, high frequency electronic applications or for devices that operates in harsh environments. However, diamond electronic devices are still in the laboratory stage due to the lack of large substrates and the complexity of diamond doping. On another hand, surface acoustic wave filters based on diamond are commercially available. Diamond is especially suited for acoustic applications because of its exceptional mechanical properties. The ...

  12. Electromagnetic shower counter

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The octogonal block of lead glass is observed by eight photomultiplier tubes. Four or five such counters, arranged in succession, are used on each arm of the bispectrometer in order to detect heavy particles of the same family as those recently observed at Brookhaven and SLAC. They provide a means of identifying electrons. The arrangement of eight lateral photomultiplier tubes offers an efficient means of collecting the photons produced in the showers and determining, with a high resolution, the energy of the incident electrons. The total width at half-height is less than 6.9% for electrons having an energy of 1 GeV.

  13. CVD diamond metallization and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Fraimovitch, D., E-mail: dimitryf@mail.tau.ac.il [Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv (Israel); Adelberd, A.; Marunko, S. [Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv (Israel); Lefeuvre, G. [Micron Semiconductor Ltd. Royal Buildings, Marlborough Road, Lancing Business Park, BN15 8SJ (United Kingdom); Ruzin, A. [Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv (Israel)

    2017-02-11

    In this study we compared three diamond substrate grades: polycrystalline, optical grade single crystal, and electronic grade single crystal for detector application. Beside the bulk type, the choice of contact material, pre-treatment, and sputtering process details have shown to alter significantly the diamond detector performance. Characterization of diamond substrate permittivity and losses indicate grade and crystallinity related, characteristic differences for frequencies in 1 kHz–1 MHz range. Substantial grade related variations were also observed in surface electrostatic characterization performed by contact potential difference (CPD) mode of an atomic force microscope. Study of conductivity variations with temperature reveal that bulk trap energy levels are also dependent on the crystal grade.

  14. CVD diamond metallization and characterization

    International Nuclear Information System (INIS)

    Fraimovitch, D.; Adelberd, A.; Marunko, S.; Lefeuvre, G.; Ruzin, A.

    2017-01-01

    In this study we compared three diamond substrate grades: polycrystalline, optical grade single crystal, and electronic grade single crystal for detector application. Beside the bulk type, the choice of contact material, pre-treatment, and sputtering process details have shown to alter significantly the diamond detector performance. Characterization of diamond substrate permittivity and losses indicate grade and crystallinity related, characteristic differences for frequencies in 1 kHz–1 MHz range. Substantial grade related variations were also observed in surface electrostatic characterization performed by contact potential difference (CPD) mode of an atomic force microscope. Study of conductivity variations with temperature reveal that bulk trap energy levels are also dependent on the crystal grade.

  15. Diamond and Diamond-Like Materials as Hydrogen Isotope Barriers

    International Nuclear Information System (INIS)

    Foreman, L.R.; Barbero, R.S.; Carroll, D.W.; Archuleta, T.; Baker, J.; Devlin, D.; Duke, J.; Loemier, D.; Trukla, M.

    1999-01-01

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The purpose of this project was to develop diamond and diamond-like thin-films as hydrogen isotope permeation barriers. Hydrogen embrittlement limits the life of boost systems which otherwise might be increased to 25 years with a successful non-reactive barrier. Applications in tritium processing such as bottle filling processes, tritium recovery processes, and target filling processes could benefit from an effective barrier. Diamond-like films used for low permeability shells for ICF and HEDP targets were also investigated. Unacceptable high permeabilities for hydrogen were obtained for plasma-CVD diamond-like-carbon films

  16. Method of dehalogenation using diamonds

    Science.gov (United States)

    Farcasiu, Malvina; Kaufman, Phillip B.; Ladner, Edward P.; Anderson, Richard R.

    2000-01-01

    A method for preparing olefins and halogenated olefins is provided comprising contacting halogenated compounds with diamonds for a sufficient time and at a sufficient temperature to convert the halogenated compounds to olefins and halogenated olefins via elimination reactions.

  17. Quantum photonic networks in diamond

    KAUST Repository

    Lončar, Marko; Faraon, Andrei

    2013-01-01

    Advances in nanotechnology have enabled the opportunity to fabricate nanoscale optical devices and chip-scale systems in diamond that can generate, manipulate, and store optical signals at the single-photon level. In particular, nanophotonics has

  18. CVD diamond detectors and dosimeters

    International Nuclear Information System (INIS)

    Manfredotti, C.; Fizzotti, F.; LoGiudice, A.; Paolini, C.; Oliviero, P.; Vittone, E.; Torino Univ., Torino

    2002-01-01

    Natural diamond, because of its well-known properties of tissue-equivalence, has recorded a wide spreading use in radiotherapy planning with electron linear accelerators. Artificial diamond dosimeters, as obtained by Chemical Vapour Deposition (CVD) could be capable to offer the same performances and they can be prepared in different volumes and shapes. The dosimeter sensitivity per unit volume may be easily proved to be better than standard ionization microchamber. We have prepared in our laboratory CVD diamond microchamber (diamond tips) in emispherical shape with an external diameter of 200 μm, which can be used both as X-ray beam profilometers and as microdosimeters for small field applications like stereotaxy and also for in vivo applications. These dosimeters, which are obtained on a wire substrate that could be either metallic or SiC or even graphite, display good performances also as ion or synchrotron X-rays detectors

  19. DIAMONDS: Engineering Distributed Object Systems

    National Research Council Canada - National Science Library

    Cheng, Evan

    1997-01-01

    This report describes DIAMONDS, a research project at Syracuse University, that is dedicated to producing both a methodology and corresponding tools to assist in the development of heterogeneous distributed software...

  20. Modeling of diamond radiation detectors

    International Nuclear Information System (INIS)

    Milazzo, L.; Mainwood, A.

    2004-01-01

    We have built up a computer simulation of the detection mechanism in the diamond radiation detectors. The diamond detectors can be fabricated from a chemical vapour deposition polycrystalline diamond film. In this case, the trapping-detrapping and recombination at the defects inside the grains and at the grain boundaries degrade the transport properties of the material and the charge induction processes. These effects may strongly influence the device's response. Previous simulations of this kind of phenomena in the diamond detectors have generally been restricted to the simple detector geometries and homogeneous distribution of the defects. In our model, the diamond film (diamond detector) is simulated by a grid. We apply a spatial and time discretization, regulated by the grid resolution, to the equations describing the charge transport and, by using the Shockley-Ramo theorem, we calculate the signal induced on the electrodes. In this way, we can simulate the effects of the nonhomogeneous distributions of the trapping, recombination, or scattering centers and can investigate the differences observed when different particles, energies, and electrode configurations are used. The simulation shows that the efficiency of the detector increases linearly with the average grain size, that the charge collection distance is small compared to the dimensions of a single grain, and that for small grains, the trapping at the intragrain defects is insignificant compared to the effect of the grain boundaries

  1. Quantum photonic networks in diamond

    KAUST Repository

    Lončar, Marko

    2013-02-01

    Advances in nanotechnology have enabled the opportunity to fabricate nanoscale optical devices and chip-scale systems in diamond that can generate, manipulate, and store optical signals at the single-photon level. In particular, nanophotonics has emerged as a powerful interface between optical elements such as optical fibers and lenses, and solid-state quantum objects such as luminescent color centers in diamond that can be used effectively to manipulate quantum information. While quantum science and technology has been the main driving force behind recent interest in diamond nanophotonics, such a platform would have many applications that go well beyond the quantum realm. For example, diamond\\'s transparency over a wide wavelength range, large third-order nonlinearity, and excellent thermal properties are of great interest for the implementation of frequency combs and integrated Raman lasers. Diamond is also an inert material that makes it well suited for biological applications and for devices that must operate in harsh environments. Copyright © Materials Research Society 2013.

  2. A nuclear proportional counter

    International Nuclear Information System (INIS)

    1973-01-01

    The invention relates to a nuclear proportional counter comprising in a bulb filled with a low-pressure gas, a wire forming an anode and a cathode, characterized in that said cathode is constituted by two plane plates parallel to each other and to the anode wire, and in that two branches of a circuit are connected to the anode wire end-portions, each branch comprising a pre-amplifier, a measuring circuit consisting of a differentiator-integrator-differentiator amplifier and a zero detector, one of the branches comprising an adjustable delay circuit, both branches jointly attacking a conversion circuit for converting the pulse duration into amplitudes said conversion circuit being followed by a multi-channel analyzer, contingently provided with a recorder [fr

  3. Silica aerogel Cerenkov counter

    International Nuclear Information System (INIS)

    Yasumi, S.; Masaike, A.; Yamamoto, A.; Yoshimura, Y.; Kawai, H.

    1984-03-01

    In order to obtain silica aerogel radiators of good quality, the prescription used by Saclay group has been developed. We have done several experiments using beams from KEK.PS to test the performance of a Cerenkov counter with aerogel modules produced in KEK. It turned out that these modules had excellent quality. The production rate of silica aerogel in KEK is 15 -- 20 litres a week. Silica aerogel modules of 20 x 10 x 3 cm 3 having the refractive index of 1.058 are successfully being used by Kyoto University group in the KEK experiment E92 (Σ). Methodes to produce silica aerogel with higher refractive index than 1.06 has been investigated both by heating an module with the refractive index of 1.06 and by hydrolyzing tetraethyl silicate. (author)

  4. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

    Olson, R.E.; Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  5. Diamonds: Exploration, mines and marketing

    Science.gov (United States)

    Read, George H.; Janse, A. J. A. (Bram)

    2009-11-01

    The beauty, value and mystique of exceptional quality diamonds such as the 603 carat Lesotho Promise, recovered from the Letseng Mine in 2006, help to drive a multi-billion dollar diamond exploration, mining and marketing industry that operates in some 45 countries across the globe. Five countries, Botswana, Russia, Canada, South Africa and Angola account for 83% by value and 65% by weight of annual diamond production, which is mainly produced by four major companies, De Beers, Alrosa, Rio Tinto and BHP Billiton (BHPB), which together account for 78% by value and 72% by weight of annual diamond production for 2007. During the last twelve years 16 new diamond mines commenced production and 4 re-opened. In addition, 11 projects are in advanced evaluation and may begin operations within the next five years. Exploration for diamondiferous kimberlites was still energetic up to the last quarter of 2008 with most work carried out in Canada, Angola, Democratic Republic of the Congo (DRC) and Botswana. Many kimberlites were discovered but no new economic deposits were outlined as a result of this work, except for the discovery and possible development of the Bunder project by Rio Tinto in India. Exploration methods have benefitted greatly from improved techniques of high resolution geophysical aerial surveying, new research into the geochemistry of indicator minerals and further insights into the formation of diamonds and the relation to tectonic/structural events in the crust and mantle. Recent trends in diamond marketing indicate that prices for rough diamonds and polished goods were still rising up to the last quarter of 2008 and subsequently abruptly sank in line with the worldwide financial crisis. Most analysts predict that prices will rise again in the long term as the gap between supply and demand will widen because no new economic diamond discoveries have been made recently. The disparity between high rough and polished prices and low share prices of publicly

  6. Space and power efficient hybrid counters array

    Science.gov (United States)

    Gara, Alan G [Mount Kisco, NY; Salapura, Valentina [Chappaqua, NY

    2009-05-12

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  7. Permanently calibrated interpolating time counter

    International Nuclear Information System (INIS)

    Jachna, Z; Szplet, R; Kwiatkowski, P; Różyc, K

    2015-01-01

    We propose a new architecture of an integrated time interval counter that provides its permanent calibration in the background. Time interval measurement and the calibration procedure are based on the use of a two-stage interpolation method and parallel processing of measurement and calibration data. The parallel processing is achieved by a doubling of two-stage interpolators in measurement channels of the counter, and by an appropriate extension of control logic. Such modification allows the updating of transfer characteristics of interpolators without the need to break a theoretically infinite measurement session. We describe the principle of permanent calibration, its implementation and influence on the quality of the counter. The precision of the presented counter is kept at a constant level (below 20 ps) despite significant changes in the ambient temperature (from −10 to 60 °C), which can cause a sevenfold decrease in the precision of the counter with a traditional calibration procedure. (paper)

  8. Are diamond nanoparticles cytotoxic?

    Science.gov (United States)

    Schrand, Amanda M; Huang, Houjin; Carlson, Cataleya; Schlager, John J; Omacr Sawa, Eiji; Hussain, Saber M; Dai, Liming

    2007-01-11

    Finely divided carbon particles, including charcoal, lampblack, and diamond particles, have been used for ornamental and official tattoos since ancient times. With the recent development in nanoscience and nanotechnology, carbon-based nanomaterials (e.g., fullerenes, nanotubes, nanodiamonds) attract a great deal of interest. Owing to their low chemical reactivity and unique physical properties, nanodiamonds could be useful in a variety of biological applications such as carriers for drugs, genes, or proteins; novel imaging techniques; coatings for implantable materials; and biosensors and biomedical nanorobots. Therefore, it is essential to ascertain the possible hazards of nanodiamonds to humans and other biological systems. We have, for the first time, assessed the cytotoxicity of nanodiamonds ranging in size from 2 to 10 nm. Assays of cell viability such as mitochondrial function (MTT) and luminescent ATP production showed that nanodiamonds were not toxic to a variety of cell types. Furthermore, nanodiamonds did not produce significant reactive oxygen species. Cells can grow on nanodiamond-coated substrates without morphological changes compared to controls. These results suggest that nanodiamonds could be ideal for many biological applications in a diverse range of cell types.

  9. A new route to process diamond wires

    Directory of Open Access Journals (Sweden)

    Marcello Filgueira

    2003-06-01

    Full Text Available We propose an original route to process diamond wires, denominated In Situ Technology, whose fabrication involves mechanical conformation processes, such as rotary forging, copper tubes restacking, and thermal treatments, such as sintering and recrystallisation of a bronze 4 wt.% diamond composite. Tensile tests were performed, reaching an ultimate tensile strength (UTS of 230 MPa for the diameter of Æ = 1.84 mm. Scanning electron microscopy showed the diamond crystals distribution along the composite rope during its manufacture, as well as the diamond adhesion to the bronze matrix. Cutting tests were carried out with the processed wire, showing a probable performance 4 times higher than the diamond sawing discs, however its probable performance was about 5 to 8 times less than the conventional diamond wires (pearl system due to the low abrasion resistance of the bronze matrix, and low adhesion between the pair bronze-diamond due to the use of not metallised diamond single crystals.

  10. High vacuum tribology of polycrystalline diamond coatings

    Indian Academy of Sciences (India)

    Polycrystalline diamond coatings; hot filament CVD; high vacuum tribology. 1. Introduction .... is a characteristic of graphite. We mark the (diamond ... coefficient of friction due to changes in substrate temperature. The average coefficient of.

  11. Diamond-based materials for biomedical applications

    CERN Document Server

    Narayan, Roger

    2013-01-01

    Carbon is light-weight, strong, conductive and able to mimic natural materials within the body, making it ideal for many uses within biomedicine. Consequently a great deal of research and funding is being put into this interesting material with a view to increasing the variety of medical applications for which it is suitable. Diamond-based materials for biomedical applications presents readers with the fundamental principles and novel applications of this versatile material. Part one provides a clear introduction to diamond based materials for medical applications. Functionalization of diamond particles and surfaces is discussed, followed by biotribology and biological behaviour of nanocrystalline diamond coatings, and blood compatibility of diamond-like carbon coatings. Part two then goes on to review biomedical applications of diamond based materials, beginning with nanostructured diamond coatings for orthopaedic applications. Topics explored include ultrananocrystalline diamond for neural and ophthalmologi...

  12. Ohmic contacts to semiconducting diamond

    Science.gov (United States)

    Zeidler, James R.; Taylor, M. J.; Zeisse, Carl R.; Hewett, C. A.; Delahoussaye, Paul R.

    1990-10-01

    Work was carried out to improve the electron beam evaporation system in order to achieve better deposited films. The basic system is an ion pumped vacuum chamber, with a three-hearth, single-gun e-beam evaporator. Four improvements were made to the system. The system was thoroughly cleaned and new ion pump elements, an e-gun beam adjust unit, and a more accurate crystal monitor were installed. The system now has a base pressure of 3 X 10(exp -9) Torr, and can easily deposit high-melting-temperature metals such as Ta with an accurately controlled thickness. Improved shadow masks were also fabricated for better alignment and control of corner contacts for electrical transport measurements. Appendices include: A Thermally Activated Solid State Reaction Process for Fabricating Ohmic Contacts to Semiconducting Diamond; Tantalum Ohmic Contacts to Diamond by a Solid State Reaction Process; Metallization of Semiconducting Diamond: Mo, Mo/Au, and Mo/Ni/Au; Specific Contact Resistance Measurements of Ohmic Contracts to Diamond; and Electrical Activation of Boron Implanted into Diamond.

  13. Organophosphonate biofunctionalization of diamond electrodes.

    Science.gov (United States)

    Caterino, R; Csiki, R; Wiesinger, M; Sachsenhauser, M; Stutzmann, M; Garrido, J A; Cattani-Scholz, A; Speranza, Giorgio; Janssens, S D; Haenen, K

    2014-08-27

    The modification of the diamond surface with organic molecules is a crucial aspect to be considered for any bioapplication of this material. There is great interest in broadening the range of linker molecules that can be covalently bound to the diamond surface. In the case of protein immobilization, the hydropathicity of the surface has a major influence on the protein conformation and, thus, on the functionality of proteins immobilized at surfaces. For electrochemical applications, particular attention has to be devoted to avoid that the charge transfer between the electrode and the redox center embedded in the protein is hindered by a thick insulating linker layer. This paper reports on the grafting of 6-phosphonohexanoic acid on OH-terminated diamond surfaces, serving as linkers to tether electroactive proteins onto diamond surfaces. X-ray photoelectron spectroscopy (XPS) confirms the formation of a stable layer on the surface. The charge transfer between electroactive molecules and the substrate is studied by electrochemical characterization of the redox activity of aminomethylferrocene and cytochrome c covalently bound to the substrate through this linker. Our work demonstrates that OH-terminated diamond functionalized with 6-phosphonohexanoic acid is a suitable platform to interface redox-proteins, which are fundamental building blocks for many bioelectronics applications.

  14. Nanocrystalline diamond films for biomedical applications

    DEFF Research Database (Denmark)

    Pennisi, Cristian Pablo; Alcaide, Maria

    2014-01-01

    Nanocrystalline diamond films, which comprise the so called nanocrystalline diamond (NCD) and ultrananocrystalline diamond (UNCD), represent a class of biomaterials possessing outstanding mechanical, tribological, and electrical properties, which include high surface smoothness, high corrosion...... performance of nanocrystalline diamond films is reviewed from an application-specific perspective, covering topics such as enhancement of cellular adhesion, anti-fouling coatings, non-thrombogenic surfaces, micropatterning of cells and proteins, and immobilization of biomolecules for bioassays. In order...

  15. Medical applications of diamond particles & surfaces

    OpenAIRE

    Roger J Narayan; Ryan D. Boehm; Anirudha V. Sumant

    2011-01-01

    Diamond has been considered for use in several medical applications due to its unique mechanical, chemical, optical, and biological properties. In this paper, methods for preparing synthetic diamond surfaces and particles are described. In addition, recent developments involving the use of diamond in prostheses, sensing, imaging, and drug delivery applications are reviewed. These developments suggest that diamond-containing structures will provide significant improvements in the diagnosis and...

  16. Ultimate Atomic Bling: Nanotechnology of Diamonds

    International Nuclear Information System (INIS)

    Dahl, Jeremy

    2010-01-01

    Diamonds exist in all sizes, from the Hope Diamond to minuscule crystals only a few atoms across. The smallest of these diamonds are created naturally by the same processes that make petroleum. Recently, researchers discovered that these 'diamondoids' are formed in many different structural shapes, and that these shapes can be used like LEGO blocks for nanotechnology. This talk will discuss the discovery of these nano-size diamonds and highlight current SLAC/Stanford research into their applications in electronics and medicine.

  17. Diamond and diamond-like films for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J.M.

    1993-01-01

    This section is a compilation of transparency templates which describe the goals of the Office of Transportation Materials (OTM) Tribology Program. The positions of personnel on the OTM are listed. The role and mission of the OTM is reviewed. The purpose of the Tribology Program is stated to be `to obtain industry input on program(s) in tribology/advanced lubricants areas of interest`. The objective addressed here is to identify opportunities for cost effective application of diamond and diamond-like carbon in transportation systems.

  18. A portable neutron coincidence counter

    Energy Technology Data Exchange (ETDEWEB)

    Peurrung, A.J.; Bowyer, S.M.; Craig, R.A.; Dudder, G.B.; Knopf, M.A.; Panisko, M.E.; Reeder, P.L.; Stromswold, D.C.; Sunberg, D.S.

    1996-11-01

    Pacific Northwest National Laboratory has designed and constructed a prototype portable neutron coincidence counter intended for use in a variety of applications, such as the verification and inspection of weapons components, safety measurements for novel and challenging situations, portable portal deployment to prevent the transportation of fissile materials, uranium enrichment measurements in hard-to-reach locations, waste assays for objects that cannot be measured by existing measurement systems, and decontamination and decommissioning. The counting system weighs less than 40 kg and is composed of parts each weighing no more than 5 kg. In addition, the counter`s design is sufficiently flexible to allow rapid, reliable assembly around containers of nearly arbitrary size and shape. The counter is able to discern the presence of 1 kg of weapons-grade plutonium within an ALR-8 (30-gal drum) in roughly 100 seconds and 10 g in roughly 1000 seconds. The counter`s electronics are also designed for maximum adaptability, allowing operation under a wide variety of circumstances, including exposure to gamma-ray fields of 1 R/h. This report provides a detailed review of the design and construction process. Finally, preliminary experimental measurements that confirm the performance capabilities of this counter are discussed. 6 refs., 18 figs., 3 tabs.

  19. Multiple channel programmable coincidence counter

    Science.gov (United States)

    Arnone, Gaetano J.

    1990-01-01

    A programmable digital coincidence counter having multiple channels and featuring minimal dead time. Neutron detectors supply electrical pulses to a synchronizing circuit which in turn inputs derandomized pulses to an adding circuit. A random access memory circuit connected as a programmable length shift register receives and shifts the sum of the pulses, and outputs to a serializer. A counter is input by the adding circuit and downcounted by the seralizer, one pulse at a time. The decoded contents of the counter after each decrement is output to scalers.

  20. What is Counter-Enlightenment?

    OpenAIRE

    Darrin M. McMahon

    2017-01-01

    This article counters recent suggestions that there was no such thing as a “Counter-Enlightenment” or “Counter-Enlightenments,” and that such terms ought thus to be abandoned.   While acknowledging inevitable difficulties with the terms, the article argues that there can be no doubting the reality.   European countries faced a variety of vehement and self-conscious movements that defined themselves precisely through their opposition to what they took to be the corrosive effects of the Enlight...

  1. Diamonds at the golden point

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    Alongside the CMS Pixel Luminosity Telescope (PLT) – installed last month (see here) – lie diamond detectors. No ordinary gems, these lab-grown diamonds will be playing a vital role in Run 2: differentiating signals from collision products with those from the beam background.   The BCM detector's green "c-shaped" printed circuit board is mounted on the PLT/BCM carbon-fibre carriage ready for installation. Earlier this year, the CMS BRIL project installed beam condition monitors (BCM) at the heart of the CMS detector. Designed to measure the online luminosity and beam background as close as possible to the LHC beam pipe, the BCMs use radiation-hard diamonds to differentiate between background and collision signals. The BCM also protects the CMS silicon trackers from damaging beam losses, by aborting the beam if the signal currents measured are above an acceptable threshold. These new BCMs are designed with Run 2 bunches in mind. &ldq...

  2. Status of diamond particle detectors

    Science.gov (United States)

    Krammer, M.; Adam, W.; Bauer, C.; Berdermann, E.; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fish, D.; Foulon, F.; Friedl, M.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Knöpfle, K. T.; Manfredi, P. F.; Meier, D.; Mishina, M.; LeNormand, F.; Pan, L. S.; Pernegger, H.; Pernicka, M.; Re, V.; Riester, G. L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Turchetta, R.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.

    1998-11-01

    To continue the exciting research in the field of particle physics new accelerators and experiments are under construction. In some of these experiments, e.g. ATLAS and CMS at the Large Hadron Collider at CERN or HERA-B at DESY, the detectors have to withstand an extreme environment. The detectors must be radiation hard, provide a very fast signal, and be as thin as possible. The properties of CVD diamond allow to fulfill these requirements and make it an ideal material for the detectors close to the interaction region of these experiments, i.e. the vertex detectors or the inner trackers. The RD42 collaboration is developing diamond detectors for these applications. The program of RD42 includes the improvement of the charge collection properties of CVD diamond, the study of the radiation hardness and the development of low-noise radiation hard readout electronics. An overview of the progress achieved during the last years will be given.

  3. Pulsed laser deposition of metallic films on the surface of diamond particles for diamond saw blades

    International Nuclear Information System (INIS)

    Jiang Chao; Luo Fei; Long Hua; Hu Shaoliu; Li Bo; Wang Youqing

    2005-01-01

    Ti or Ni films have been deposited on the diamond particle surfaces by pulsed laser deposition. Compressive resistance of the uncoated and coated diamond particles was measured, respectively, in the experiments. The compressive resistance of the Ti-coated diamonds particles was found much higher than that of the uncoated ones. It increased by 39%. The surface morphology is observed by the metallography microscope. The surface of the uncoated diamonds particles had many hollows and flaws, while the surface of Ni-coated diamond particles was flat and smooth, and the surface of Ti-coated diamond particles had some metal masses that stood out of the surface of the Ti-coated film. The components of the metallic films of diamond particles were examined by X-ray diffractometry (XRD). TiC was found formed on the Ti-coated diamond surface, which resulted in increased surface bonding strength between the diamond particles and the Ti films. Meanwhile, TiC also favored improving the bonding strength between the coated diamond particles and the binding materials. Moreover, the bending resistance of the diamond saw blade made of Ti-coated diamond was drastically higher than that of other diamond saw blades, which also played an important role in improving the blade's cutting ability and lifetime. Therefore, it was most appropriate that the diamond saw blade was made of Ti-coated diamond particles rather than other materials

  4. Diamonds on Diamond: structural studies at extreme conditions on the Diamond Light Source.

    Science.gov (United States)

    McMahon, M I

    2015-03-06

    Extreme conditions (EC) research investigates how the structures and physical and chemical properties of materials change when subjected to extremes of pressure and temperature. Pressures in excess of one million times atmospheric pressure can be achieved using a diamond anvil cell, and, in combination with high-energy, micro-focused radiation from a third-generation synchrotron such as Diamond, detailed structural information can be obtained using either powder or single-crystal diffraction techniques. Here, I summarize some of the research drivers behind international EC research, and then briefly describe the techniques by which high-quality diffraction data are obtained. I then highlight the breadth of EC research possible on Diamond by summarizing four examples from work conducted on the I15 and I19 beamlines, including a study which resulted in the first research paper from Diamond. Finally, I look to the future, and speculate as to the type of EC research might be conducted at Diamond over the next 10 years. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  5. Graphene grown out of diamond

    Science.gov (United States)

    Gu, Changzhi; Li, Wuxia; Xu, Jing; Xu, Shicong; Lu, Chao; Xu, Lifang; Li, Junjie; Zhang, Shengbai

    2016-10-01

    Most applications of graphene need a suitable support substrate to present its excellent properties. But transferring graphene onto insulators or growing graphene on foreign substrates could cause properties diminishing. This paper reports the graphene growth directly out of diamond (111) by B doping, guided by first-principles calculations. The spontaneous graphene formation occurred due to the reconstruction of the diamond surface when the B doping density and profile are adequate. The resulting materials are defect free with high phase purity/carrier mobility, controllable layer number, and good uniformity, which can be potentially used directly for device fabrication, e.g., high-performance devices requiring good thermal conductivity.

  6. Diamond radiation detectors II. CVD diamond development for radiation detectors

    International Nuclear Information System (INIS)

    Kania, D.R.

    1997-01-01

    Interest in radiation detectors has supplied some of the impetus for improving the electronic properties of CVD diamond. In the present discussion, we will restrict our attention to polycrystalhne CVD material. We will focus on the evolution of these materials over the past decade and the correlation of detector performance with other properties of the material

  7. In-vivo radiation counter

    International Nuclear Information System (INIS)

    Pollard, D.E.

    1983-01-01

    This patent specification describes a radiation counter utilizing at least one detector for sensing radiation from a living body. The radiation counter also includes an aperture for forming a corridor between the body and the detector. A shield outside the corridor prevents passage of background radiation through the corridor and gaining access to the detector. The counter also includes a device for isolating a selected portion of the body from the corridor such that radiation counting is restricted to a region of the body through a separate detector. The corridor formation permits a user to stand in an upright position while the detector and detectors are able to separately monitor different sections of the body. The radiation counter overcomes the problem of obtaining accurate and quick measurements or radiation doses sustained by a large group of persons. (author)

  8. Transparent nanocrystalline diamond coatings and devices

    Science.gov (United States)

    Sumant, Anirudha V.; Khan, Adam

    2017-08-22

    A method for coating a substrate comprises producing a plasma ball using a microwave plasma source in the presence of a mixture of gases. The plasma ball has a diameter. The plasma ball is disposed at a first distance from the substrate and the substrate is maintained at a first temperature. The plasma ball is maintained at the first distance from the substrate, and a diamond coating is deposited on the substrate. The diamond coating has a thickness. Furthermore, the diamond coating has an optical transparency of greater than about 80%. The diamond coating can include nanocrystalline diamond. The microwave plasma source can have a frequency of about 915 MHz.

  9. Recent results on CVD diamond radiation sensors

    Science.gov (United States)

    Weilhammer, P.; Adam, W.; Bauer, C.; Berdermann, E.; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; v. d. Eijk, R.; van Eijk, B.; Fallou, A.; Fish, D.; Fried, M.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Knopfle, K. T.; Krammer, M.; Manfredi, P. F.; Meier, D.; LeNormand; Pan, L. S.; Pernegger, H.; Pernicka, M.; Plano, R.; Re, V.; Riester, J. L.; Roe, S.; Roff; Rudge, A.; Schieber, M.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Turchetta, R.; RD 42 Collaboration

    1998-02-01

    CVD diamond radiation sensors are being developed for possible use in trackers in the LHC experiments. The diamond promises to be radiation hard well beyond particle fluences that can be tolerated by Si sensors. Recent results from the RD 42 collaboration on charge collection distance and on radiation hardness of CVD diamond samples will be reported. Measurements with diamond tracking devices, both strip detectors and pixel detectors, will be discussed. Results from beam tests using a diamond strip detector which was read out with fast, 25 ns shaping time, radiation-hard pipeline electronics will be presented.

  10. Diamond Sensors for Energy Frontier Experiments

    CERN Document Server

    Schnetzer, Steve

    2014-01-01

    We discuss the use of diamond sensors in high-energy, high-i ntensity collider experiments. Re- sults from diamond sensor based beam conditions monitors in the ATLAS and CMS experiments at the CERN Large Hadron Collider (LHC) are presented and pla ns for diamond based luminosity monitors for the upcoming LHC run are described. We describe recent measurements on single crystal diamond sensors that indicate a polarization effec t that causes a reduction of charge col- lection efficiency as a function of particle flux. We conclude by describing new developments on the promising technology of 3D diamond sensors.

  11. High-speed parallel counter

    International Nuclear Information System (INIS)

    Gus'kov, B.N.; Kalinnikov, V.A.; Krastev, V.R.; Maksimov, A.N.; Nikityuk, N.M.

    1985-01-01

    This paper describes a high-speed parallel counter that contains 31 inputs and 15 outputs and is implemented by integrated circuits of series 500. The counter is designed for fast sampling of events according to the number of particles that pass simultaneously through the hodoscopic plane of the detector. The minimum delay of the output signals relative to the input is 43 nsec. The duration of the output signals can be varied from 75 to 120 nsec

  12. Channel coincidence counter: version 1

    International Nuclear Information System (INIS)

    Krick, M.S.; Menlove, H.O.

    1980-06-01

    A thermal neutron coincidence counter has been designed for the assay of fast critical assembly fuel drawers and plutonium-bearing fuel rods. The principal feature of the detector is a 7-cm by 7-cm by 97-cm detector channel, which provides a uniform neutron detection efficiency of 16% along the central 40 cm of the channel. The electronics system is identical to that used for the High-Level Neutron Coincidence Counter

  13. Portable microcomputer controlled radiation counter

    International Nuclear Information System (INIS)

    Mason, E.W.; Weber, J.M.

    1984-01-01

    A portable microcomputer controlled counter for use as a radiation counter is described. The counter uses digital processing of input pulses from a radiation detector. The number of counts received by the microcomputer per unit time is used to calculate a value for display using a calibration factor obtained during physical calibration of the instrument with a radiation source or with a pulse generator. The keyboard is used to enter calibration points. The number of calibration points which may be entered depends on the degree of accuracy desired by the user. The high voltage generator which drives the detector is triggered by pulses from the microcomputer in relation to the count rate. After processing the count, the resulting count rate or dose rate is displayed on the liquid crystal display. The counter is autoranging in which the decimal point is shifted as necessary by the microcomputer. The units displayed are determined by the user by means of a multiposition switch. Low battery and an overrange condition are displayed. An interface is provided via a connector to allow parallel transmission of data to peripheral devices. Low battery power consumption is featured. The counter is capable of providing more accurate readings than currently available counters

  14. Lateral overgrowth of diamond film on stripes patterned Ir/HPHT-diamond substrate

    Science.gov (United States)

    Wang, Yan-Feng; Chang, Xiaohui; Liu, Zhangcheng; Liu, Zongchen; Fu, Jiao; Zhao, Dan; Shao, Guoqing; Wang, Juan; Zhang, Shaopeng; Liang, Yan; Zhu, Tianfei; Wang, Wei; Wang, Hong-Xing

    2018-05-01

    Epitaxial lateral overgrowth (ELO) of diamond films on patterned Ir/(0 0 1)HPHT-diamond substrates have been carried out by microwave plasma CVD system. Ir/(0 0 1)HPHT-diamond substrates are fabricated by photolithographic and magnetron sputtering technique. The morphology of the as grown ELO diamond film is characterized by optical microscopy and scanning electronic microscopy. The quality and stress of the ELO diamond film are investigated by surface etching pit density and micro-Raman spectroscopy. Two ultraviolet photodetectors are fabricated on ELO diamond area and non-ELO diamond area prepared on same substrate, and that one on ELO diamond area indicates better photoelectric properties. All results indicate quality of ELO diamond film is improved.

  15. CVD diamond windows for infrared synchrotron applications

    International Nuclear Information System (INIS)

    Sussmann, R.S.; Pickles, C.S.J.; Brandon, J.R.; Wort, C.J.H.; Coe, S.E.; Wasenczuk, A.; Dodge, C.N.; Beale, A.C.; Krehan, A.J.; Dore, P.; Nucara, A.; Calvani, P.

    1998-01-01

    This paper describes the attributes that make diamond a unique material for infrared synchrotron beam experiments. New developments in diamond synthesised by Chemical Vapour Deposition (CVD) promise to extend the range of applications which have been hitherto limited by the availability and cost of large-size single-crystal diamond. Polycrystalline CVD diamond components such as large (100 mm) diameter windows with extremely good transparency over a wide spectral range are now commercially available. Properties of CVD diamond of relevance to optical applications, such as mechanical strength, thermal conductivity and absolute bulk absorption, are discussed. It is shown that although some of the properties of CVD diamond (similar to other polycrystalline industrial ceramics) are affected by the grain structure, currently produced CVD diamond optical components have the quality and performance required for numerous demanding applications

  16. The Many Facets of Diamond Crystals

    Directory of Open Access Journals (Sweden)

    Yuri N. Palyanov

    2018-01-01

    Full Text Available This special issue is intended to serve as a multidisciplinary forum covering broad aspects of the science, technology, and application of synthetic and natural diamonds. This special issue contains 12 papers, which highlight recent investigations and developments in diamond research related to the diverse problems of natural diamond genesis, diamond synthesis and growth using CVD and HPHT techniques, and the use of diamond in both traditional applications, such as mechanical machining of materials, and the new recently emerged areas, such as quantum technologies. The results presented in the contributions collected in this special issue clearly demonstrate that diamond occupies a very special place in modern science and technology. After decades of research, this structurally very simple material still poses many intriguing scientific questions and technological challenges. It seems undoubted that diamond will remain the center of attraction for many researchers for many years to come.

  17. Recent Advances in Diamond Detectors

    CERN Document Server

    Trischuk, W.

    2008-01-01

    With the commissioning of the LHC expected in 2009, and the LHC upgrades expected in 2012, ATLAS and CMS are planning for detector upgrades for their innermost layers requiring radiation hard technologies. Chemical Vapor Deposition (CVD) diamond has been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle and CDF and is now planned for all LHC experiments. This material is now being considered as an alternate sensor for use very close to the interaction region of the super LHC where the most extreme radiation conditions will exist. Recently the RD42 collaboration constructed, irradiated and tested polycrystalline and single-crystal chemical vapor deposition diamond sensors to the highest fluences available. We present beam test results of chemical vapor deposition diamond up to fluences of 1.8 x 10^16 protons/cm^2 showing that both polycrystalline and single-crystal chemical vapor deposition diamonds follow a single damage curve allowing one t...

  18. What is Counter-Enlightenment?

    Directory of Open Access Journals (Sweden)

    Darrin M. McMahon

    2017-02-01

    Full Text Available This article counters recent suggestions that there was no such thing as a “Counter-Enlightenment” or “Counter-Enlightenments,” and that such terms ought thus to be abandoned.   While acknowledging inevitable difficulties with the terms, the article argues that there can be no doubting the reality.   European countries faced a variety of vehement and self-conscious movements that defined themselves precisely through their opposition to what they took to be the corrosive effects of the Enlightenment.  In the process, they defined the main terms of an enduring vision of the world that we now associate with the Right.

  19. Plea and counter-plea

    International Nuclear Information System (INIS)

    1979-06-01

    The bulk of papers written during the hearing 'Plea and counter-plea', the so-called 'Gorleben hearing', which was held from 28th March until 3rd April 1979, comprises ca. 4,200 pages. It consists of the written comments put forward by the critics of nuclear energy, the minutes of the hearing as well as the supplementary statements of the counter-critics. This report is trying to confront those essential objections made by the critics which put in doubt the feasibility of a fuel-cycle centre with regard to safety engineering with the facts which are considered correct from the view of the DWK. The oral and written explanations of the counter-critics are particularly referred to in this debate. (orig./HP) [de

  20. Portable counter for geological research

    Energy Technology Data Exchange (ETDEWEB)

    Russell, O J

    1949-05-01

    A portable counter which has been developed for prospecting for radio-active uranium and thorium minerals, for general geological investigations, and as an ultra-sensitive detector of lost or mislaid radium, is described. The aforementioned general usage includes the identification of changes in strata by means of the investigation of the slight amount of residual activity pressent in most minerals. The apparatus, which consists essentially of a scaled-down version of a standard laboratory Geiger-Muller counter, is highly sensitive since a variation equivalent to 4% of the cosmic ray background can be detected by a three-minute count.

  1. ''Conventional'' Cerenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Foley, K.J.

    1977-01-01

    Cherenkov counters to be used with ISABELLE are described. The three counters used in the Hadron Spectrometer can be used to identify particles in the range 10 to 40 GeV/c with pions separated from heavier particles down to approximately 3 GeV/c. A longer spectrometer for 400 x 400 GeV operation should also be used. The spectrometers may be used with CO 2 and H 2 . The range of particle identification of 8 to 60 GeV/c with pions separated from heavier particles down to approximately 5 GeV/c is possible

  2. Copper-micrometer-sized diamond nanostructured composites

    International Nuclear Information System (INIS)

    Nunes, D; Livramento, V; Fernandes, H; Silva, C; Carvalho, P A; Shohoji, N; Correia, J B

    2011-01-01

    Reinforcement of a copper matrix with diamond enables tailoring the properties demanded for thermal management applications at high temperature, such as the ones required for heat sink materials in low activated nuclear fusion reactors. For an optimum compromise between thermal conductivity and mechanical properties, a novel approach based on multiscale diamond dispersions is proposed: a Cu-nanodiamond composite produced by milling is used as a nanostructured matrix for further dispersion of micrometer-sized diamondDiamond). A series of Cu-nanodiamond mixtures have been milled to establish a suitable nanodiamond fraction. A refined matrix with homogeneously dispersed nanoparticles was obtained with 4 at.% μDiamond for posterior mixture with microdiamond and subsequent consolidation. Preliminary consolidation by hot extrusion of a mixture of pure copper and μDiamond has been carried out to define optimal processing parameters. The materials produced were characterized by x-ray diffraction, scanning and transmission electron microscopy and microhardness measurements.

  3. Diamond nanowires: fabrication, structure, properties, and applications.

    Science.gov (United States)

    Yu, Yuan; Wu, Liangzhuan; Zhi, Jinfang

    2014-12-22

    C(sp(3) )C-bonded diamond nanowires are wide band gap semiconductors that exhibit a combination of superior properties such as negative electron affinity, chemical inertness, high Young's modulus, the highest hardness, and room-temperature thermal conductivity. The creation of 1D diamond nanowires with their giant surface-to-volume ratio enhancements makes it possible to control and enhance the fundamental properties of diamond. Although theoretical comparisons with carbon nanotubes have shown that diamond nanowires are energetically and mechanically viable structures, reproducibly synthesizing the crystalline diamond nanowires has remained challenging. We present a comprehensive, up-to-date review of diamond nanowires, including a discussion of their synthesis along with their structures, properties, and applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The Toucan's Diamond

    Science.gov (United States)

    2006-06-01

    The Southern constellation Tucana (the Toucan) is probably best known as the home of the Small Magellanic Cloud, one of the satellite galaxies of the Milky Way. But Tucana also hosts another famous object that shines thousands of lights, like a magnificent, oversized diamond in the sky: the globular cluster 47 Tucanae. More popularly known as 47 Tuc, it is surpassed in size and brightness by only one other globular cluster, Omega Centauri. Globular clusters are gigantic families of stars, comprising several tens of thousands of stars, all thought to be born at the same time from the same cloud of gas [1]. As such, they constitute unique laboratories for the study of how stars evolve and interact. This is even more so because they are located at the same distance, so the brightness of different types of stars, at different stages in their evolution can be directly compared. The stars in globular clusters are held together by their mutual gravity which gives them their spherical shape, hence their name. Globular clusters are thought to be among the oldest objects in our Milky Way galaxy, and contain therefore mostly old, low-mass stars. ESO PR Photo 20/06 ESO PR Photo 20/06 Globular Cluster 47 Tuc 47 Tucanae is an impressive globular cluster that is visible with the unaided eye from the southern hemisphere. It was discovered in 1751 by the French astronomer Nicholas Louis de Lacaille who cataloged it in his list of southern nebulous objects. Located about 16 000 light years away, it has a total mass of about 1 million times the mass of the Sun and is 120 light years across, making it appear on the sky as big as the full moon. The colour image of 47 Tucanae presented here was taken with FORS1 on ESO's Very Large Telescope in 2001. The image covers only the densest, very central part of the cluster. The globular cluster extends in reality four times further away! As can be seen however, the density of stars rapidly drops off when moving away from the centre. The red

  5. Diamond turning machine controller implementation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Conductive diamond electrodes for water purification

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Martínez-Huitle

    2007-12-01

    Full Text Available Nowadays, synthetic diamond has been studied for its application in wastewater treatment, electroanalysis, organic synthesis and sensor areas; however, its use in the water disinfection/purification is its most relevant application. The new electrochemistry applications of diamond electrodes open new perspectives for an easy, effective, and chemical free water treatment. This article highlights and summarizes the results of a selection of papers dealing with electrochemical disinfection using synthetic diamond films.

  7. Characterization of diamond amorphized by ion implantation

    International Nuclear Information System (INIS)

    Allen, W.R.; Lee, E.H.

    1992-01-01

    Single crystal diamond has been implanted at 1 MeV with 2 x 10 20 Ar/m 2 . Rutherford backscattering spectrometry in a channeled geometry revealed a broad amorphized region underlying a thin, partially crystalline layer. Raman spectroscopy disclosed modifications in the bonding characteristic of the appearance of non-diamond carbon. The complementary nature of the two analysis techniques is demonstrated. The Knoop hardness of the implanted diamond was reduced by implantation

  8. Modifying thin film diamond for electronic applications

    International Nuclear Information System (INIS)

    Baral, B.

    1999-01-01

    The unique combination of properties that diamond possesses are being exploited in both electronic and mechanical applications. An important step forward in the field has been the ability to grow thin film diamond by chemical vapour deposition (CVD) methods and to control parameters such as crystal orientation, dopant level and surface roughness. An extensive understanding of the surface of any potential electronic material is vital to fully comprehend its behaviour within device structures. The surface itself ultimately controls key aspects of device performance when interfaced with other materials. This study has provided insight into important chemical reactions on polycrystalline CVD diamond surfaces, addressing how certain surface modifications will ultimately affect the properties of the material. A review of the structure, bonding, properties and potential of diamond along with an account of the current state of diamond technology and CVD diamond growth is provided. The experimental chapter reviews bulk material and surface analytical techniques employed in this work and is followed by an investigation of cleaning treatments for polycrystalline CVD diamond aimed at removing non-diamond carbon from the surface. Selective acid etch treatments are compared and contrasted for efficacy with excimer laser irradiation and hydrogen plasma etching. The adsorption/desorption kinetics of potential dopant-containing precursors on polycrystalline CVD diamond surfaces have been investigated to compare their effectiveness at introducing dopants into the diamond during the growth stage. Both boron and sulphur-containing precursor compounds have been investigated. Treating polycrystalline CVD diamond in various atmospheres / combination of atmospheres has been performed to enhance electron field emission from the films. Films which do not emit electrons under low field conditions can be modified such that they emit at fields as low as 10 V/μm. The origin of this enhancement

  9. Surface Structure of Aerobically Oxidized Diamond Nanocrystals

    Science.gov (United States)

    2014-10-27

    Diamond. Phys. Rev. Lett. 2000, 84, 5160−5163. (31) Ownby, P. D.; Yang, X.; Liu, J. Calculated X-Ray-Diffraction Data for Diamond Polytypes. J. Am. Ceram...Surfaces from Ab-Initio Calculations . Phys. Rev. B 1995, 51, 14669−14685. (39) Ferrari, A. C.; Robertson, J. Raman Spectroscopy of Amorphous, Nanostructured...Y.; Takami, S.; Kubo , M.; Belosludov, R. V.; Miyamoto, A.; Imamura, A.; Gamo, M. N.; Ando, T. First-Principle Study on Reactions of Diamond (100

  10. Entanglement, holography and causal diamonds

    Science.gov (United States)

    de Boer, Jan; Haehl, Felix M.; Heller, Michal P.; Myers, Robert C.

    2016-08-01

    We argue that the degrees of freedom in a d-dimensional CFT can be reorganized in an insightful way by studying observables on the moduli space of causal diamonds (or equivalently, the space of pairs of timelike separated points). This 2 d-dimensional space naturally captures some of the fundamental nonlocality and causal structure inherent in the entanglement of CFT states. For any primary CFT operator, we construct an observable on this space, which is defined by smearing the associated one-point function over causal diamonds. Known examples of such quantities are the entanglement entropy of vacuum excitations and its higher spin generalizations. We show that in holographic CFTs, these observables are given by suitably defined integrals of dual bulk fields over the corresponding Ryu-Takayanagi minimal surfaces. Furthermore, we explain connections to the operator product expansion and the first law of entanglemententropy from this unifying point of view. We demonstrate that for small perturbations of the vacuum, our observables obey linear two-derivative equations of motion on the space of causal diamonds. In two dimensions, the latter is given by a product of two copies of a two-dimensional de Sitter space. For a class of universal states, we show that the entanglement entropy and its spin-three generalization obey nonlinear equations of motion with local interactions on this moduli space, which can be identified with Liouville and Toda equations, respectively. This suggests the possibility of extending the definition of our new observables beyond the linear level more generally and in such a way that they give rise to new dynamically interacting theories on the moduli space of causal diamonds. Various challenges one has to face in order to implement this idea are discussed.

  11. Entanglement, holography and causal diamonds

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Jan de [Institute of Physics, Universiteit van Amsterdam,Science Park 904, 1090 GL Amsterdam (Netherlands); Haehl, Felix M. [Centre for Particle Theory & Department of Mathematical Sciences, Durham University,South Road, Durham DH1 3LE (United Kingdom); Heller, Michal P.; Myers, Robert C. [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada)

    2016-08-29

    We argue that the degrees of freedom in a d-dimensional CFT can be re-organized in an insightful way by studying observables on the moduli space of causal diamonds (or equivalently, the space of pairs of timelike separated points). This 2d-dimensional space naturally captures some of the fundamental nonlocality and causal structure inherent in the entanglement of CFT states. For any primary CFT operator, we construct an observable on this space, which is defined by smearing the associated one-point function over causal diamonds. Known examples of such quantities are the entanglement entropy of vacuum excitations and its higher spin generalizations. We show that in holographic CFTs, these observables are given by suitably defined integrals of dual bulk fields over the corresponding Ryu-Takayanagi minimal surfaces. Furthermore, we explain connections to the operator product expansion and the first law of entanglement entropy from this unifying point of view. We demonstrate that for small perturbations of the vacuum, our observables obey linear two-derivative equations of motion on the space of causal diamonds. In two dimensions, the latter is given by a product of two copies of a two-dimensional de Sitter space. For a class of universal states, we show that the entanglement entropy and its spin-three generalization obey nonlinear equations of motion with local interactions on this moduli space, which can be identified with Liouville and Toda equations, respectively. This suggests the possibility of extending the definition of our new observables beyond the linear level more generally and in such a way that they give rise to new dynamically interacting theories on the moduli space of causal diamonds. Various challenges one has to face in order to implement this idea are discussed.

  12. Thermal Conductivity of Diamond Composites

    Directory of Open Access Journals (Sweden)

    Fedor M. Shakhov

    2009-12-01

    Full Text Available A major problem challenging specialists in present-day materials sciences is the development of compact, cheap to fabricate heat sinks for electronic devices, primarily for computer processors, semiconductor lasers, high-power microchips, and electronics components. The materials currently used for heat sinks of such devices are aluminum and copper, with thermal conductivities of about 250 W/(m·K and 400 W/(m·K, respectively. Significantly, the thermal expansion coefficient of metals differs markedly from those of the materials employed in semiconductor electronics (mostly silicon; one should add here the low electrical resistivity metals possess. By contrast, natural single-crystal diamond is known to feature the highest thermal conductivity of all the bulk materials studied thus far, as high as 2,200 W/(m·K. Needless to say, it cannot be applied in heat removal technology because of high cost. Recently, SiC- and AlN-based ceramics have started enjoying wide use as heat sink materials; the thermal conductivity of such composites, however, is inferior to that of metals by nearly a factor two. This prompts a challenging scientific problem to develop diamond-based composites with thermal characteristics superior to those of aluminum and copper, adjustable thermal expansion coefficient, low electrical conductivity and a moderate cost, below that of the natural single-crystal diamond. The present review addresses this problem and appraises the results reached by now in studying the possibility of developing composites in diamond-containing systems with a view of obtaining materials with a high thermal conductivity.

  13. Diamond turning of thermoplastic polymers

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Diamond coating in accelerator structure

    International Nuclear Information System (INIS)

    Lin, X.E.

    1998-08-01

    The future accelerators with 1 GeV/m gradient will give rise to hundreds of degrees instantaneous temperature rise on the copper surface. Due to its extraordinary thermal and electric properties, diamond coating on the surface is suggested to remedy this problem. Multi-layer structure, with the promise of even more temperature reduction, is also discussed, and a proof of principle experiment is being carried out

  15. Thin film diamond microstructure applications

    Science.gov (United States)

    Roppel, T.; Ellis, C.; Ramesham, R.; Jaworske, D.; Baginski, M. E.; Lee, S. Y.

    1991-01-01

    Selective deposition and abrasion, as well as etching in atomic oxygen or reduced-pressure air, have been used to prepare patterned polycrystalline diamond films which, on further processing by anisotropic Si etching, yield the microstructures of such devices as flow sensors and accelerometers. Both types of sensor have been experimentally tested in the respective functions of hot-wire anemometer and both single- and double-hinged accelerometer.

  16. Anisotropic diamond etching through thermochemical reaction between Ni and diamond in high-temperature water vapour.

    Science.gov (United States)

    Nagai, Masatsugu; Nakanishi, Kazuhiro; Takahashi, Hiraku; Kato, Hiromitsu; Makino, Toshiharu; Yamasaki, Satoshi; Matsumoto, Tsubasa; Inokuma, Takao; Tokuda, Norio

    2018-04-27

    Diamond possesses excellent physical and electronic properties, and thus various applications that use diamond are under development. Additionally, the control of diamond geometry by etching technique is essential for such applications. However, conventional wet processes used for etching other materials are ineffective for diamond. Moreover, plasma processes currently employed for diamond etching are not selective, and plasma-induced damage to diamond deteriorates the device-performances. Here, we report a non-plasma etching process for single crystal diamond using thermochemical reaction between Ni and diamond in high-temperature water vapour. Diamond under Ni films was selectively etched, with no etching at other locations. A diamond-etching rate of approximately 8.7 μm/min (1000 °C) was successfully achieved. To the best of our knowledge, this rate is considerably greater than those reported so far for other diamond-etching processes, including plasma processes. The anisotropy observed for this diamond etching was considerably similar to that observed for Si etching using KOH.

  17. 76 FR 37684 - Airworthiness Directives; Diamond Aircraft Industries GmbH Model (Diamond) DA 40 Airplanes...

    Science.gov (United States)

    2011-06-28

    ... Industries GmbH Model (Diamond) DA 40 Airplanes Equipped With Certain Cabin Air Conditioning Systems AGENCY... inspections of the Diamond Model DA 40 airplanes equipped with a VCS installed per Premier Aircraft Service... GmbH Model (Diamond) DA 40 Airplanes Equipped With Certain Cabin Air Conditioning Systems: Docket No...

  18. Comparison between beryllium and diamond-backing plates in diamond-anvil cells

    DEFF Research Database (Denmark)

    Periotto, Benedetta; Nestola, Fabrizio; Balic Zunic, Tonci

    2011-01-01

    A direct comparison between two complete intensity datasets, collected on the same sample loaded in two identical diamond-anvil pressure cells equipped, respectively, with beryllium and diamond backing plates was performed. The results clearly demonstrate that the use of diamond-backing plates...

  19. Wetting of the diamond surface

    International Nuclear Information System (INIS)

    Hansen, J.O.

    1987-01-01

    The surface conditions which lead to a wide variation in the wettability of diamond surfaces have been investigated using macroscopic surfaces to allow for the crystal anisotropy. A wetting balance method of calculating adhesion tension and hence contact angle has been used for diamonds having major faces near the [111] and [110] lattice planes. Three classes of behaviour have been identified. Surface analyses by Rutherford Backscattering of helium ions, X-ray Photoelectron Spectroscopy and Low Energy Electron Diffraction (LEED) have been used to define the role of the oxygen coverage of the surface in the transition I → O → H. Ferric ion has a hydrophilizing effect on the diamond surface, thought to be the consequence of attachment to the hydroxyl groups at the surface by a ligand mechanism. Other transition metal ions did not show this effect. The phenomenon of hydration of the surface, i.e. progressively more hydrophilic behaviour on prolonged exposure to liquid water, has been quantified. Imbibition or water penetration at microcracks are thought unlikely, and a water cluster build-up at hydrophilic sites is thought to be the best explanation. Dynamic studies indicate little dependence of the advancing contact angle on velocity for velocities up to 10 -4 m/s, and slight dependence of the receding contact angle. Hence advancing angles by this technique are similar to equilibrated contact angles found by optical techniques, but the receding angles are lower than found by other non-dynamic measurements

  20. ATLAS diamond Beam Condition Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Gorisek, A. [CERN (Switzerland)]. E-mail: andrej.gorisek@cern.ch; Cindro, V. [J. Stefan Institute (Slovenia); Dolenc, I. [J. Stefan Institute (Slovenia); Frais-Koelbl, H. [Fotec (Austria); Griesmayer, E. [Fotec (Austria); Kagan, H. [Ohio State University, OH (United States); Korpar, S. [J. Stefan Institute (Slovenia); Kramberger, G. [J. Stefan Institute (Slovenia); Mandic, I. [J. Stefan Institute (Slovenia); Meyer, M. [CERN (Switzerland); Mikuz, M. [J. Stefan Institute (Slovenia); Pernegger, H. [CERN (Switzerland); Smith, S. [Ohio State University, OH (United States); Trischuk, W. [University of Toronto (Canada); Weilhammer, P. [CERN (Switzerland); Zavrtanik, M. [J. Stefan Institute (Slovenia)

    2007-03-01

    The ATLAS experiment has chosen to use diamond for its Beam Condition Monitor (BCM) given its radiation hardness, low capacitance and short charge collection time. In addition, due to low leakage current diamonds do not require cooling. The ATLAS Beam Condition Monitoring system is based on single beam bunch crossing measurements rather than integrating the accumulated particle flux. Its fast electronics will allow separation of LHC collisions from background events such as beam gas interactions or beam accidents. There will be two stations placed symmetrically about the interaction point along the beam axis at z=+/-183.8cm. Timing of signals from the two stations will provide almost ideal separation of beam-beam interactions and background events. The ATLAS BCM module consists of diamond pad detectors of 1cm{sup 2} area and 500{mu}m thickness coupled to a two-stage RF current amplifier. The production of the final detector modules is almost done. A S/N ratio of 10:1 has been achieved with minimum ionizing particles (MIPs) in the test beam setup at KEK. Results from the test beams and bench measurements are presented.

  1. ATLAS diamond Beam Condition Monitor

    International Nuclear Information System (INIS)

    Gorisek, A.; Cindro, V.; Dolenc, I.; Frais-Koelbl, H.; Griesmayer, E.; Kagan, H.; Korpar, S.; Kramberger, G.; Mandic, I.; Meyer, M.; Mikuz, M.; Pernegger, H.; Smith, S.; Trischuk, W.; Weilhammer, P.; Zavrtanik, M.

    2007-01-01

    The ATLAS experiment has chosen to use diamond for its Beam Condition Monitor (BCM) given its radiation hardness, low capacitance and short charge collection time. In addition, due to low leakage current diamonds do not require cooling. The ATLAS Beam Condition Monitoring system is based on single beam bunch crossing measurements rather than integrating the accumulated particle flux. Its fast electronics will allow separation of LHC collisions from background events such as beam gas interactions or beam accidents. There will be two stations placed symmetrically about the interaction point along the beam axis at z=+/-183.8cm. Timing of signals from the two stations will provide almost ideal separation of beam-beam interactions and background events. The ATLAS BCM module consists of diamond pad detectors of 1cm 2 area and 500μm thickness coupled to a two-stage RF current amplifier. The production of the final detector modules is almost done. A S/N ratio of 10:1 has been achieved with minimum ionizing particles (MIPs) in the test beam setup at KEK. Results from the test beams and bench measurements are presented

  2. Status of diamond particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Krammer, M.; Adam, W.; Friedl, M.; Hrubec, J.; Pernegger, H.; Pernicka, M. [Institut fuer Hochenergiephysik der Oesterr. Akademie d. Wissenschaften, Nikolsdorferg. 18, A-1050 Vienna (Austria); Bauer, C. [MPI fuer Kernphysik, D-69029 Heidelberg (Germany); Berdermann, E.; Stelzer, H. [GSI, Darmstadt (Germany); Bogani, F. [LENS, Florence (Italy); Borchi, E.; Bruzzi, M.; Sciortino, S. [University of Florence, Florence (Italy); Colledani, C.; Dulinski, W.; Husson, D.; LeNormand, F.; Riester, G.L.; Turchetta, R. [LEPSI, CRN Strasbourg (France); Conway, J.; Fish, D.; Schnetzer, S.; Stone, R.; Tesarek, R.; Thomson, G.B.; Walsh, A.M. [Rutgers University, Piscataway, NJ (United States); Dabrowski, W.; Kaplon, J.; Meier, D.; Roe, S.; Rudge, A.; Wedenig, R.; Weilhammer, P. [CERN, CH-1211 Geneva (Switzerland); Delpierre, P.; Hallewell, G. [CPPM, Marseille (France); Deneuville, A.; Cheeraert, E. [LEPES, Grenoble (France); Eijk, B.V.; Hartjes, F. [NIKHEF, Amsterdam (Netherlands); Fallou, A. [CPPM, Marseille (France); Foulon, F. [Centre d' Etudes de Saclay, 91191 Gif-Sur-Yvette (France); Gan, K.K.; Kagan, H.; Kass, R.; Trawick, M.; Zoeller, M. [The Ohio State University, Columbus, OH (United States); Grigoriev, E.; Knoepfle, K.T. [MPI fuer Kernphysik, D-69029 Heidelberg (Germany); Hall-Wilton, R. [Bristol University, Bristol (United Kingdom); Han, S.; Ziock, H. [Los Alamos National Laboratory, Research Division, Los Alamos, NM (United States); Kania, D. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Manfredi, P.F.; Re, V.; Speziali, V. [Universita di Pavia, Dipartimento di Elettronica, 27100 Pavia (Italy); Mishina, M. [FNAL, Batavia, IL (United States); Pan, L.S. [Sandia National Laboratory, Albuquerque, NM (United States); Roff, D.; Tapper, R.J. [Bristol University, Bristol (United Kingdom); Trischuk, W. [University of Toronto, Toronto (Canada)

    1998-11-21

    To continue the exciting research in the field of particle physics new accelerators and experiments are under construction. In some of these experiments, e.g. ATLAS and CMS at the Large Hadron Collider at CERN or HERA-B at DESY, the detectors have to withstand an extreme environment. The detectors must be radiation hard, provide a very fast signal, and be as thin as possible. The properties of CVD diamond allow to fulfill these requirements and make it an ideal material for the detectors close to the interaction region of these experiments, i.e. the vertex detectors or the inner trackers. The RD42 collaboration is developing diamond detectors for these applications. The program of RD42 includes the improvement of the charge collection properties of CVD diamond, the study of the radiation hardness and the development of low-noise radiation hard readout electronics. An overview of the progress achieved during the last years will be given. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Status of diamond particle detectors

    International Nuclear Information System (INIS)

    Krammer, M.; Adam, W.; Friedl, M.; Hrubec, J.; Pernegger, H.; Pernicka, M.; Bauer, C.; Berdermann, E.; Stelzer, H.; Bogani, F.; Borchi, E.; Bruzzi, M.; Sciortino, S.; Colledani, C.; Dulinski, W.; Husson, D.; LeNormand, F.; Riester, G.L.; Turchetta, R.; Conway, J.; Fish, D.; Schnetzer, S.; Stone, R.; Tesarek, R.; Thomson, G.B.; Walsh, A.M.; Dabrowski, W.; Kaplon, J.; Meier, D.; Roe, S.; Rudge, A.; Wedenig, R.; Weilhammer, P.; Delpierre, P.; Hallewell, G.; Deneuville, A.; Cheeraert, E.; Eijk, B.V.; Hartjes, F.; Fallou, A.; Foulon, F.; Gan, K.K.; Kagan, H.; Kass, R.; Trawick, M.; Zoeller, M.; Grigoriev, E.; Knoepfle, K.T.; Hall-Wilton, R.; Han, S.; Ziock, H.; Kania, D.; Manfredi, P.F.; Re, V.; Speziali, V.; Mishina, M.; Pan, L.S.; Roff, D.; Tapper, R.J.; Trischuk, W.

    1998-01-01

    To continue the exciting research in the field of particle physics new accelerators and experiments are under construction. In some of these experiments, e.g. ATLAS and CMS at the Large Hadron Collider at CERN or HERA-B at DESY, the detectors have to withstand an extreme environment. The detectors must be radiation hard, provide a very fast signal, and be as thin as possible. The properties of CVD diamond allow to fulfill these requirements and make it an ideal material for the detectors close to the interaction region of these experiments, i.e. the vertex detectors or the inner trackers. The RD42 collaboration is developing diamond detectors for these applications. The program of RD42 includes the improvement of the charge collection properties of CVD diamond, the study of the radiation hardness and the development of low-noise radiation hard readout electronics. An overview of the progress achieved during the last years will be given. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  4. ATLAS diamond Beam Condition Monitor

    CERN Document Server

    Gorišek, A; Dolenc, I; Frais-Kölbl, H; Griesmayer, E; Kagan, H; Korpar, S; Kramberger, G; Mandic, I; Meyer, M; Mikuz, M; Pernegger, H; Smith, S; Trischuk, W; Weilhammer, P; Zavrtanik, M

    2007-01-01

    The ATLAS experiment has chosen to use diamond for its Beam Condition Monitor (BCM) given its radiation hardness, low capacitance and short charge collection time. In addition, due to low leakage current diamonds do not require cooling. The ATLAS Beam Condition Monitoring system is based on single beam bunch crossing measurements rather than integrating the accumulated particle flux. Its fast electronics will allow separation of LHC collisions from background events such as beam gas interactions or beam accidents. There will be two stations placed symmetrically about the interaction point along the beam axis at . Timing of signals from the two stations will provide almost ideal separation of beam–beam interactions and background events. The ATLAS BCM module consists of diamond pad detectors of area and thickness coupled to a two-stage RF current amplifier. The production of the final detector modules is almost done. A S/N ratio of 10:1 has been achieved with minimum ionizing particles (MIPs) in the test bea...

  5. Direct Coating of Nanocrystalline Diamond on Steel

    Science.gov (United States)

    Tsugawa, Kazuo; Kawaki, Shyunsuke; Ishihara, Masatou; Hasegawa, Masataka

    2012-09-01

    Nanocrystalline diamond films have been successfully deposited on stainless steel substrates without any substrate pretreatments to promote diamond nucleation, including the formation of interlayers. A low-temperature growth technique, 400 °C or lower, in microwave plasma chemical vapor deposition using a surface-wave plasma has cleared up problems in diamond growth on ferrous materials, such as the surface graphitization, long incubation time, substrate softening, and poor adhesion. The deposited nanocrystalline diamond films on stainless steel exhibit good adhesion and tribological properties, such as a high wear resistance, a low friction coefficient, and a low aggression strength, at room temperature in air without lubrication.

  6. Ultimate Atomic Bling: Nanotechnology of Diamonds

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, Jeremy

    2010-05-25

    Diamonds exist in all sizes, from the Hope Diamond to minuscule crystals only a few atoms across. The smallest of these diamonds are created naturally by the same processes that make petroleum. Recently, researchers discovered that these 'diamondoids' are formed in many different structural shapes, and that these shapes can be used like LEGO blocks for nanotechnology. This talk will discuss the discovery of these nano-size diamonds and highlight current SLAC/Stanford research into their applications in electronics and medicine.

  7. Undoped CVD diamond films for electrochemical applications

    International Nuclear Information System (INIS)

    Mosinska, Lidia; Fabisiak, Kazimierz; Paprocki, Kazimierz; Kowalska, Magdalena; Popielarski, Pawel; Szybowicz, Miroslaw

    2013-01-01

    By using different deposition conditions, the CVD diamond films with different qualities and orientation were grown by the hot-filament CVD technique. The object of this article is to summarize and discuss relation between structural, physical and electrochemical properties of different diamond electrodes. The physical properties of the Hot Filament CVD microcrystalline diamond films are analyzed by scanning electron microscopy and Raman spectroscopy. In presented studies two different electrodes were used of the diamond grain sizes around 200 nm and 10 μm, as it was estimated from SEM picture. The diamond layers quality was checked on basis of FWHM (Full width at Half Maximum) of 1332 cm −1 diamond Raman peak. The ratio of sp 3 /sp 2 carbon bonds was determined by 1550 cm −1 G band and 1350 cm −1 D band in the Raman spectrum. The electrochemical properties were analyzed using (CV) cyclic voltammetry measurements in aqueous solutions. The sensitivity of undoped diamond electrodes depends strongly on diamond film quality and concentration of amorphous carbon phase in the diamond layer

  8. CVD diamond substrates for electronic devices

    International Nuclear Information System (INIS)

    Holzer, H.

    1996-03-01

    In this study the applicability of chemical vapor deposition (CVD) diamond as a material for heat spreaders was investigated. Economical evaluations on the production of heat spreaders were also performed. For the diamond synthesis the hot-filament and microwave method were used respectively. The deposition parameters were varied in a way that free standing diamond layers with a thickness of 80 to 750 microns and different qualities were obtained. The influence of the deposition parameters on the relevant film properties was investigated and discussed. With both the hot-filament and microwave method it was possible to deposit diamond layers having a thermal conductivity exceeding 1200 W/mK and therefore to reach the quality level for commercial uses. The electrical resistivity was greater than 10 12 Ωcm. The investigation of the optical properties was done by Raman-, IR- and cathodoluminescence spectroscopy. Because of future applications of diamond-aluminium nitride composites as highly efficient heat spreaders diamond deposition an AIN was investigated. An improved substrate pretreatment prior to diamond deposition showed promising results for better performance of such composite heat spreaders. Both free standing layers and diamond-AIN composites could be cut by a CO2 Laser in Order to get an exact size geometry. A reduction of the diamond surface roughness was achieved by etching with manganese powder or cerium. (author)

  9. The Eros of Counter Education

    Science.gov (United States)

    Luzon, Pinhas

    2016-01-01

    Erotic Counter Education (ECE) is the educational position of the late Ilan Gur-Ze'ev. In ECE Gur-Ze'ev combines two opposing positions in the philosophy of education, one teleological and anti-utopian, the other teleological and utopian. In light of this unique combination, I ask what mediates between these two poles and suggest that the answer…

  10. Dimensions of Counter-Narratives

    DEFF Research Database (Denmark)

    2019-01-01

    The book welcomes proposals for chapter contributions on a wide array of topics related to the narratological notion of counter-narratives. By way of example, the topic has hitherto been treated by disciplines and subjects such as literature studies, organization studies, corporate communication...

  11. Countering 21st Century Threats

    DEFF Research Database (Denmark)

    Scharling Pedersen, Peter; Pillai, Chad M.; Hun, Lee Jae

    2015-01-01

    ), Counter-Terrorism (CT), and Security and Stability Operations (SSO). • Establishing a construct that allows a strategic Whole-of-Government capacity for operations coordinated by joint interagency task forces. • Continue to developing the Global SOF network. • Increased intelligence sharing in areas...

  12. The Micro Trench Gas Counter

    International Nuclear Information System (INIS)

    Schmitz, J.

    1991-07-01

    A novel design is presented for a gas avalanche chamber with micro-strip gas readout. While existing gaseous microstrip detectors (Micro-strip Gas Counters, Knife edge chambers) have a minimum anode pitch of the order of 100 μm, the pitch of the discussed Micro Trench Gas Counter goes down to 30-50 μm. This leads to a better position resolution and two track separation, and a higher radiation resistivity. Its efficiency and signal speed are expected to be the same as the Microstrip Gas Counter. The energy resolution of the device is expected to be equal to or better than 10 percent for the 55 Fe peak. Since the anode strip dimensions are larger than those in a MSGC, the device may be not as sensitive to discharges and mechanical damage. In this report production of the device is briefly described, and predictions on its operation are made based on electric field calculations and experience with the Microstrip Gas Counter. The authors restrict themselves to the application in High Energy Physics. (author). 10 refs.; 9 figs

  13. Diamond Growth in the Subduction Factory

    Science.gov (United States)

    Bureau, H.; Frost, D. J.; Bolfan-Casanova, N.; Leroy, C.; Estève, I.

    2014-12-01

    Natural diamonds are fabulous probes of the deep Earth Interior. They are the evidence of the deep storage of volatile elements, carbon at first, but also hydrogen and chlorine trapped as hydrous fluids in inclusions. The study of diamond growth processes in the lithosphere and mantle helps for our understanding of volatile elements cycling between deep reservoirs. We know now that inclusion-bearing diamonds similar to diamonds found in nature (i.e. polycrystalline, fibrous and coated diamonds) can grow in hydrous fluids or melts (Bureau et al., GCA 77, 202-214, 2012). Therefore, we propose that the best environment to promote such diamonds is the subduction factory, where highly hydrous fluids or melts are present. When oceanic plates are subducted in the lithosphere, they carry an oceanic crust soaked with seawater. While the slabs are traveling en route to the mantle, dehydration processes generate saline fluids highly concentrated in NaCl. In the present study we have experimentally shown that diamonds can grow from the saline fluids (up to 30 g/l NaCl in water) generated in subducted slabs. We have performed multi-anvil press experiments at 6-7 GPa and from 1300 to 1400°C during 6:00 hours to 30:00 hours. We observed large areas of new diamond grown in epitaxy on pure diamond seeds in salty hydrous carbonated melts, forming coated gems. The new rims are containing multi-component primary inclusions. Detailed characterizations of the diamonds and their inclusions have been performed and will be presented. These experimental results suggest that multi-component salty fluids of supercritical nature migrate with the slabs, down to the deep mantle. Such fluids may insure the first stage of the deep Earth's volatiles cycling (C, H, halogen elements) en route to the transition zone and the lower mantle. We suggest that the subduction factory may also be a diamond factory.

  14. Basic Research Needs for Countering Terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

    2002-03-01

    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  15. Diamond film growth with modification properties of adhesion between substrate and diamond film

    Directory of Open Access Journals (Sweden)

    Setasuwon P.

    2004-03-01

    Full Text Available Diamond film growth was studied using chemical vapor deposition (CVD. A special equipment was build in-house, employing a welding torch, and substrate holder with a water-cooling system. Acetylene and oxygen were used as combustion gases and the substrate was tungsten carbide cobalt. It was found that surface treatments, such as diamond powder scratching or acid etching, increase the adhesion and prevent the film peel-off. Diamond powder scratching and combined diamond powder scratching with acid etching gave the similar diamond film structure with small grain and slightly rough surface. The diamond film obtained with both treatments has high adhesion and can withstand internal stress better than ones obtained by untreated surface or acid etching alone. It was also found that higher substrate temperature produced smoother surface and more uniform diamond grain.

  16. An introduction to automatic radioactive sample counters

    International Nuclear Information System (INIS)

    1980-01-01

    The subject is covered in chapters, entitled; the detection of radiation in sample counters; nucleonic equipment; liquid scintillation counting; basic features of automatic sample counters; statistics of counting; data analysis; purchase, installation, calibration and maintenance of automatic sample counters. (U.K.)

  17. Counter-discourse in Zimbabwean literature

    NARCIS (Netherlands)

    Mangena, Tendai

    2015-01-01

    Counter-Discourse in Zimbabwean Literature is a study of specific aspects of counter-discursive Zimbabwean narratives in English. In discussing the selected texts, my thesis is based on Terdiman’s (1989) the postcolonial concept of counter-discourse. In Zimbabwean literature challenges to a dominant

  18. Robust diamond meshes with unique wettability properties.

    Science.gov (United States)

    Yang, Yizhou; Li, Hongdong; Cheng, Shaoheng; Zou, Guangtian; Wang, Chuanxi; Lin, Quan

    2014-03-18

    Robust diamond meshes with excellent superhydrophobic and superoleophilic properties have been fabricated. Superhydrophobicity is observed for water with varying pH from 1 to 14 with good recyclability. Reversible superhydrophobicity and hydrophilicity can be easily controlled. The diamond meshes show highly efficient water-oil separation and water pH droplet transference.

  19. Conflict diamonds — unfinished business | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-07-22

    Jul 22, 2011 ... ... diamonds reached this year will not be effective if it is not monitored, and if the countries ... What we do know is that 75 percent of the world's gem diamonds are mined in ... It makes the Kimberley accord weaker than any other international ... a British NGO, have been nominated for the Nobel Peace Prize.

  20. Chemical vapor deposition of nanocrystalline diamond films

    International Nuclear Information System (INIS)

    Vyrovets, I.I.; Gritsyna, V.I.; Dudnik, S.F.; Opalev, O.A.; Reshetnyak, O.M.; Strel'nitskij, V.E.

    2008-01-01

    The brief review of the literature is devoted to synthesis of nanocrystalline diamond films. It is shown that the CVD method is an effective way for deposition of such nanostructures. The basic technological methods that allow limit the size of growing diamond crystallites in the film are studied.

  1. CVD diamond pixel detectors for LHC experiments

    CERN Document Server

    Wedenig, R; Bauer, C; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernicka, Manfred; Peitz, A; Pirollo, S; Polesello, P; Pretzl, Klaus P; Procario, M; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Runólfsson, O; Russ, J; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R J; Trawick, M L; Trischuk, W; Vittone, E; Wagner, A; Walsh, A M; Weilhammer, Peter; White, C; Zeuner, W; Ziock, H J; Zöller, M

    1999-01-01

    This paper reviews the development of CVD diamond pixel detectors. The preparation of the diamond pixel sensors for bump-bonding to the pixel readout electronics for the LHC and the results from beam tests carried out at CERN are described. (9 refs).

  2. CVD diamond pixel detectors for LHC experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wedenig, R.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Procario, M.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Runolfsson, O.; Russ, J.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trawick, M.; Trischuk, W.; Vittone, E.; Wagner, A.; Walsh, A.M.; Weilhammer, P.; White, C.; Zeuner, W.; Ziock, H.; Zoeller, M.; Blanquart, L.; Breugnion, P.; Charles, E.; Ciocio, A.; Clemens, J.C.; Dao, K.; Einsweiler, K.; Fasching, D.; Fischer, P.; Joshi, A.; Keil, M.; Klasen, V.; Kleinfelder, S.; Laugier, D.; Meuser, S.; Milgrome, O.; Mouthuy, T.; Richardson, J.; Sinervo, P.; Treis, J.; Wermes, N

    1999-08-01

    This paper reviews the development of CVD diamond pixel detectors. The preparation of the diamond pixel sensors for bump-bonding to the pixel readout electronics for the LHC and the results from beam tests carried out at CERN are described.

  3. CVD diamond pixel detectors for LHC experiments

    International Nuclear Information System (INIS)

    Wedenig, R.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Procario, M.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Runolfsson, O.; Russ, J.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trawick, M.; Trischuk, W.; Vittone, E.; Wagner, A.; Walsh, A.M.; Weilhammer, P.; White, C.; Zeuner, W.; Ziock, H.; Zoeller, M.; Blanquart, L.; Breugnion, P.; Charles, E.; Ciocio, A.; Clemens, J.C.; Dao, K.; Einsweiler, K.; Fasching, D.; Fischer, P.; Joshi, A.; Keil, M.; Klasen, V.; Kleinfelder, S.; Laugier, D.; Meuser, S.; Milgrome, O.; Mouthuy, T.; Richardson, J.; Sinervo, P.; Treis, J.; Wermes, N.

    1999-01-01

    This paper reviews the development of CVD diamond pixel detectors. The preparation of the diamond pixel sensors for bump-bonding to the pixel readout electronics for the LHC and the results from beam tests carried out at CERN are described

  4. The Returns on Investment Grade Diamonds

    NARCIS (Netherlands)

    Renneboog, L.D.R.

    2013-01-01

    Abstract: This paper examines the risk-return characteristics of investment grade gems (white diamonds, colored diamonds and other types of gems including sapphires, rubies, and emeralds). The transactions are coming from gem auctions and span the period 1999-2012. Over our time frame, the annual

  5. Bending diamonds by femtosecond laser ablation

    DEFF Research Database (Denmark)

    Balling, Peter; Esberg, Jakob; Kirsebom, Kim

    2009-01-01

    We present a new method based on femtosecond laser ablation for the fabrication of statically bent diamond crystals. Using this method, curvature radii of 1 m can easily be achieved, and the curvature obtained is very uniform. Since diamond is extremely tolerant to high radiation doses, partly due...

  6. Diamond sensors for future high energy experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bachmair, Felix, E-mail: bachmair@phys.ethz.ch

    2016-09-21

    With the planned upgrade of the LHC to High-Luminosity-LHC [1], the general purpose experiments ATLAS and CMS are planning to upgrade their innermost tracking layers with more radiation tolerant technologies. Chemical Vapor Deposition CVD diamond is one such technology. CVD diamond sensors are an established technology as beam condition monitors in the highest radiation areas of all LHC experiments. The RD42-collaboration at CERN is leading the effort to use CVD diamond as a material for tracking detectors operating in extreme radiation environments. An overview of the latest developments from RD42 is presented including the present status of diamond sensor production, a study of pulse height dependencies on incident particle flux and the development of 3D diamond sensors.

  7. Diamond electrophoretic microchips-Joule heating effects

    International Nuclear Information System (INIS)

    Karczemska, Anna T.; Witkowski, Dariusz; Ralchenko, Victor; Bolshakov, Andrey; Sovyk, Dmitry; Lysko, Jan M.; Fijalkowski, Mateusz; Bodzenta, Jerzy; Hassard, John

    2011-01-01

    Microchip electrophoresis (MCE) has become a mature separation technique in the recent years. In the presented research, a polycrystalline diamond electrophoretic microchip was manufactured with a microwave plasma chemical vapour deposition (MPCVD) method. A replica technique (mould method) was used to manufacture microstructures in diamond. A numerical analysis with CoventorWare TM was used to compare thermal properties during chip electrophoresis of diamond and glass microchips of the same geometries. Temperature distributions in microchips were demonstrated. Thermal, electrical, optical, chemical and mechanical parameters of the polycrystalline diamond layers are advantageous over traditionally used materials for microfluidic devices. Especially, a very high thermal conductivity coefficient gives a possibility of very efficient dissipation of Joule heat from the diamond electrophoretic microchip. This enables manufacturing of a new generation of microdevices.

  8. Engineering NV centres in Synthetic Diamond

    International Nuclear Information System (INIS)

    Matthew Markham

    2014-01-01

    The quantum properties of the nitrogen vacancy (NV) centre in diamond has prompted rapid growth in diamond research. This initial growth was driven by the fact the NV centre provides an 'easy' to manipulate quantum system along with opening up the possibility of a new material to deliver a solid state quantum computer. The NV defect is now moving from a quantum curiosity to a commercial development platform for a range of application such as as gyroscopes, timing and magnetometry as well as the more traditional quantum technologies such as quantum encryption and quantum simulation. These technologies are pushing the development needs of the material, and the processing of that material. The paper will describes the advances in CVD diamond synthesis with special attention to getting NV defects close to the surface of the diamond and how to process the material for diamond quantum optical applications. (author)

  9. Diamond detector technology: status and perspectives

    CERN Document Server

    Kagan, Harris; Artuso, M; Bachmair, F; Bäni, L; Bartosik, M; Beacham, J; Beck, H P; Bellini,, V; Belyaev, V; Bentele, B; Berdermann, E; Bergonzo, P; Bes, A; Brom, J-M; Bruzzi, M; Cerv, M; Chiodini, G; Chren, D; Cindro, V; Claus, G; Collot, J; Cumalat, J; Dabrowski, A; D'Alessandro, R; De Boer, W; Dehning, B; Dorfer, C; Dunser, M; Eremin, V; Eusebi, R; Forcolin, G; Forneris, J; Frais-Kölbl, H; Gan, K K; Gastal, M; Giroletti, C; Goffe, M; Goldstein, J; Golubev, A; Gorišek, A; Grigoriev, E; Grosse-Knetter, J; Grummer, A; Gui, B; Guthoff, M; Haughton, I; Hiti, B; Hits, D; Hoeferkamp, M; Hofmann, T; Hosslet, J; Hostachy, J-Y; Hügging, F; Hutton, C; Jansen, H; Janssen, J; Kanxheri, K; Kasieczka, G; Kass, R; Kassel, F; Kis, M; Kramberger, G; Kuleshov, S; Lacoste, A; Lagomarsino, S; Lo Giudice, A; Lukosi, E; Maazouzi, C; Mandic, I; Mathieu, C; Mcfadden, N; Menichelli, M; Mikuž, M; Morozzi, A; Moss, J; Mountain, R; Murphy, S; Muškinja, M; Oh, A; Oliviero, P; Passeri, D; Pernegger, H; Perrino, R; Picollo, F; Pomorski, M; Potenza, R; Quadt, A; Re, A; Reichmann, M; Riley, G; Roe, S; Sanz, D; Scaringella, M; Schaefer, D; Schmidt, C J; Schnetzer, S; Schreiner, T; Sciortino, S; Scorzoni, A; Seidel, S; Servoli, L; Sopko, B; Sopko, V; Spagnolo, S; Spanier, S; Stenson, K; Stone, R; Sutera, C; Taylor, Aaron; Traeger, M; Tromson, D; Trischuk, W; Tuve, C; Uplegger, L; Velthuis, J; Venturi, N; Vittone, E; Wagner, Stephen; Wallny, R; Wang, J C; Weingarten, J; Weiss, C; Wengler, T; Wermes, N; Yamouni, M; Zavrtanik, M

    2017-01-01

    The status of material development of poly-crystalline chemical vapor deposition (CVD) diamond is presented. We also present beam test results on the independence of signal size on incident par-ticle rate in charged particle detectors based on un-irradiated and irradiated poly-crystalline CVD diamond over a range of particle fluxes from 2 kHz/cm2 to 10 MHz/cm2. The pulse height of the sensors was measured with readout electronics with a peaking time of 6 ns. In addition the first beam test results from 3D detectors made with poly-crystalline CVD diamond are presented. Finally the first analysis of LHC data from the ATLAS Diamond Beam Monitor (DBM) which is based on pixelated poly-crystalline CVD diamond sensors bump-bonded to pixel readout elec-tronics is shown.

  10. Nanostructured Diamond Device for Biomedical Applications.

    Science.gov (United States)

    Fijalkowski, M; Karczemska, A; Lysko, J M; Zybala, R; KozaneckI, M; Filipczak, P; Ralchenko, V; Walock, M; Stanishevsky, A; Mitura, S

    2015-02-01

    Diamond is increasingly used in biomedical applications because of its unique properties such as the highest thermal conductivity, good optical properties, high electrical breakdown voltage as well as excellent biocompatibility and chemical resistance. Diamond has also been introduced as an excellent substrate to make the functional microchip structures for electrophoresis, which is the most popular separation technique for the determination of analytes. In this investigation, a diamond electrophoretic chip was manufactured by a replica method using a silicon mold. A polycrystalline 300 micron-thick diamond layer was grown by the microwave plasma-assisted CVD (MPCVD) technique onto a patterned silicon substrate followed by the removal of the substrate. The geometry of microstructure, chemical composition, thermal and optical properties of the resulting free-standing diamond electrophoretic microchip structure were examined by CLSM, SFE, UV-Vis, Raman, XRD and X-ray Photoelectron Spectroscopy, and by a modified laser flash method for thermal property measurements.

  11. Diamond electrophoretic microchips-Joule heating effects

    Energy Technology Data Exchange (ETDEWEB)

    Karczemska, Anna T., E-mail: anna.karczemska@p.lodz.pl [Technical University of Lodz, Institute of Turbomachinery, 219/223 Wolczanska str., Lodz (Poland); Witkowski, Dariusz [Technical University of Lodz, Institute of Turbomachinery, 219/223 Wolczanska str., Lodz (Poland); Ralchenko, Victor, E-mail: ralchenko@nsc.gpi.ru [General Physics Institute, Russian Academy of Science, 38 Vavilov str., Moscow (Russian Federation); Bolshakov, Andrey; Sovyk, Dmitry [General Physics Institute, Russian Academy of Science, 38 Vavilov str., Moscow (Russian Federation); Lysko, Jan M., E-mail: jmlysko@ite.waw.pl [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Fijalkowski, Mateusz, E-mail: petr.louda@vslib.cz [Technical University of Liberec, Faculty of Mechanical Engineering (Czech Republic); Bodzenta, Jerzy, E-mail: jerzy.bodzenta@polsl.pl [Silesian University of Technology, Institute of Physics, 2 Krzywoustego str., 44-100 Gliwice (Poland); Hassard, John, E-mail: j.hassard@imperial.ac.uk [Imperial College of Science, Technology and Medicine, London (United Kingdom)

    2011-03-15

    Microchip electrophoresis (MCE) has become a mature separation technique in the recent years. In the presented research, a polycrystalline diamond electrophoretic microchip was manufactured with a microwave plasma chemical vapour deposition (MPCVD) method. A replica technique (mould method) was used to manufacture microstructures in diamond. A numerical analysis with CoventorWare{sup TM} was used to compare thermal properties during chip electrophoresis of diamond and glass microchips of the same geometries. Temperature distributions in microchips were demonstrated. Thermal, electrical, optical, chemical and mechanical parameters of the polycrystalline diamond layers are advantageous over traditionally used materials for microfluidic devices. Especially, a very high thermal conductivity coefficient gives a possibility of very efficient dissipation of Joule heat from the diamond electrophoretic microchip. This enables manufacturing of a new generation of microdevices.

  12. Discharge quenching circuit for counters

    International Nuclear Information System (INIS)

    Karasik, A.S.

    1982-01-01

    A circuit for quenching discharges in gas-discharge detectors with working voltage of 3-5 kV based on transistors operating in the avalanche mode is described. The quenching circuit consists of a coordinating emitter follower, amplifier-shaper for avalanche key cascade control which changes potential on the counter electrodes and a shaper of discharge quenching duration. The emitter follower is assembled according to a widely used flowsheet with two transistors. The circuit permits to obtain a rectangular quenching pulse with front of 100 ns and an amplitude of up to 3.2 kV at duration of 500 μm-8 ms. Application of the quenching circuit described permits to obtain countering characteristics with the slope less than or equal to 0.02%/V and plateau extent greater than or equal to 300 V [ru

  13. Counter support for WA35

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    This assembly was equipped with 78 counters, each consisting of a lucite cone, to produce Cerenkov light, and a CsI scintillator plate of 3 mm thickness glued on the face of the cone. The experiment WA35 was set-up in the s1 beam (West Hall) by the Darmstadt-Heidelberg-Virginia-Warsaw Collaboration to measure angular distributions and multiplicities of pions and recoil protons produced by hadrons interacting in nuclei. (See Annual Report 1976 p. 39)

  14. Shock compression of diamond crystal

    OpenAIRE

    Kondo, Ken-ichi; Ahrens, Thomas J.

    1983-01-01

    Two shock wave experiments employing inclined mirrors have been carried out to determine the Hugoniot elastic limit (HEL), final shock state at 191 and 217 GPa, and the post-shock state of diamond crystal, which is shock-compressed along the intermediate direction between the and crystallographic axes. The HEL wave has a velocity of 19.9 ± 0.3 mm/µsec and an amplitude of 63 ± 28 GPa. An alternate interpretation of the inclined wedge mirror streak record suggests a ramp precursor wave and th...

  15. Toroidal plasma enhanced CVD of diamond films

    International Nuclear Information System (INIS)

    Zvanya, John; Cullen, Christopher; Morris, Thomas; Krchnavek, Robert R.; Holber, William; Basnett, Andrew; Basnett, Robert; Hettinger, Jeffrey

    2014-01-01

    An inductively coupled toroidal plasma source is used as an alternative to microwave plasmas for chemical vapor deposition of diamond films. The source, operating at a frequency of 400 kHz, synthesizes diamond films from a mixture of argon, methane, and hydrogen. The toroidal design has been adapted to create a highly efficient environment for diamond film deposition: high gas temperature and a short distance from the sample to the plasma core. Using a toroidal plasma geometry operating in the medium frequency band allows for efficient (≈90%) coupling of AC line power to the plasma and a scalable path to high-power and large-area operation. In test runs, the source generates a high flux of atomic hydrogen over a large area, which is favorable for diamond film growth. Using a deposition temperature of 900–1050 °C and a source to sample distance of 0.1–2.0 cm, diamond films are deposited onto silicon substrates. The results showed that the deposition rate of the diamond films could be controlled using the sample temperature and source to sample spacing. The results also show the films exhibit good-quality polycrystalline diamond as verified by Raman spectroscopy, x-ray diffraction, and scanning electron microscopy. The scanning electron microscopy and x-ray diffraction results show that the samples exhibit diamond (111) and diamond (022) crystallites. The Raman results show that the sp 3 peak has a narrow spectral width (FWHM 12 ± 0.5 cm −1 ) and that negligible amounts of the sp 2 band are present, indicating good-quality diamond films

  16. INTRODUCING OVER THE COUNTER COUNSELING

    Directory of Open Access Journals (Sweden)

    Nataša Bakić-Mirić

    2009-01-01

    Full Text Available A pharmacist in today’s world has a great responsibility – to help and educate patients about diverse ways for effective self-treatment. Whereas self-care is becoming increasingly popular among patients today the availability of over-the-counter medications makes it possible for patients to treat numerous conditions on their own but still under the supervision of a healthcare provider. During the pharmacist-patient encounter, the pharmacist’s obligation is to evaluate the patient’s medical condition, provide proper advice and counsel the patient on the proper course of treatment to be taken. Also by employing effective over the counter (OTC counseling as the most proper means in a pharmacist/patient communication process and, accordingly, rapport building in the OTC area, the pharmacist needs to demonstrate high energy, enthusiasm, respect, empathy, know-how of sensitive intercultural issues alongside personal appearance, body language, eye contact that all together make his/her personal “signature”. Accordingly, apart from patient education, the primary objective of OTC counseling becomes to educate pharmacists on basic principles used in assisting patients in the selection of over-the-counter (OTC products, provide examples of proper communication techniques for effective patient counseling concerning the OTC products (i.e. dosage, administration technique, storage, food and beverage interaction, monitoring etc where the pharmacist plays the key role in helping patients maximize their pharmaceutical care.

  17. Position-sensitive proportional counter

    International Nuclear Information System (INIS)

    Kopp, M.K.

    1980-01-01

    A position-sensitive proportional counter circuit uses a conventional (low-resistance, metal-wire anode) counter for spatial resolution of an ionizing event along the anode, which functions as an RC line. A pair of preamplifiers at the anode ends act as stabilized active-capacitance loads, each comprising a series-feedback, low-noise amplifier and a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at the anode ends where the difference is primarily in response to the distributed capacitance along the anode. This allows the use of lower resistance wire anodes for spatial radiation detection which simplifies the counter construction of handling of the anodes, and stabilizes the anode resistivity at high count rates (>10 6 counts/sec). (author)

  18. Carbon isotope fractionation during diamond growth in depleted peridotite: Counterintuitive insights from modelling water-maximum CHO fluids as multi-component systems

    Science.gov (United States)

    Stachel, T.; Chacko, T.; Luth, R. W.

    2017-09-01

    relatively reduced and had methane as the dominant carbon species (XCO2 = 0.1-0.5). Application of our model to a recently published set of in-situ carbon isotope analyses for peridotitic diamonds from Marange, Zimbabwe (Smit et al., 2016), which contain CH4 fluid inclusions, allows us to perfectly match the observed co-variations in δ13 C, δ15 N and N content and at the same time explain the previously counter-intuitive observation of progressive 13C enrichment in diamonds that appear to have grown from a fluid with methane as the dominant carbon species. Similarly, the almost complete absence in the published record of progressive 13C depletion trends within diamonds likely reflects ubiquitous precipitation from CH4- and CO2-bearing water-rich fluids, rather than diamond formation exclusively by carbonate-bearing and CH4-free oxidized fluids or melts.

  19. Cold cathodes on ultra-dispersed diamond base

    International Nuclear Information System (INIS)

    Alimova, A.N.; Zhirnov, V.V.; Chubun, N.N.; Belobrov, P.I.

    1998-01-01

    Prospects of application of nano diamond powders for fabrication of cold cathodes are discussed.Cold cathodes based on silicon pointed structures with nano diamond coatings were prepared.The deposition technique of diamond coating was dielectrophoresis from suspension of nano diamond powder in organic liquids.The cathodes were tested in sealed prototypes of vacuum electronic devices

  20. Proportional counter system for radiation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, M; Okudera, S

    1970-11-21

    A gas such as Xe or Kr employed in counter tubes is charged into the counter tube of a gas-flow type proportional counter for radiation measurement and into a vessel having a volume larger than that of the counter tube. The vessel communicates with the counter tube to circulate the gas via a pump through both the vessel and tube during measurement. An organic film such as a polyester synthetic resin film is used for the window of the counter tube to measure X-rays in the long wavelength range. Accordingly, a wide range of X-rays can be measured including both long and short wavelengths ranges by utilizing only one counter tube, thus permitting the gases employed to be effectively used.

  1. The Geopolitical Setting of Conflict Diamonds.

    Science.gov (United States)

    Haggerty, S. E.

    2002-05-01

    September 11, 2001 will live in infamy. Ideological differences have also led to senseless atrocities in Angola, Congo Republic, Sierra Leone, and Liberia. Hundreds of thousands have died, scores mutilated, and millions displaced. These have gone virtually unnoticed for decades. Unnoticed that is until it became evident that these barbaric acts were fueled by the sale or bartering of diamonds for arms, or by more ingenious ways that are less traceable. There is no end in sight. Industry has long recognized that about 20% of diamonds reaching the open market are smuggled from operating mines, and more recently that an additional 4% originates from conflict diamond sources. Diamond identification by laser inscription, ion implantation, or certification protocols are subject to fraudulent tampering. And these applied methods are thwarted if cutting and polishing centers are infiltrated, or if terrorist facilities are independently established. Mark ups are substantial (40-60%) from raw material to finished product. Tracking the paths of rough stones from mines to faceted gems is impractical because some 30-50 million cts of top quality material, or about 100 million stones, would require branding each year. Moreover, the long standing tradition of site-holdings and the bourse system of mixing or matching diamonds, inadvertently ensures regional anonymity. Conflict diamonds are mined in primary kimberlites and from widely dispersed alluvial fields in tropical jungle. Landscapes, eroded by 1-5 vertical km over 100 Ma, have transformed low grade primary deposits into unconsolidated sedimentary bonanzas. The current value of stones retrieved, by motivated diggers and skillful jiggers, in rebel held territories, is impossible to determine, but in 1993 amounted to tens of millions USD. Diamonds over 100 cts continue to surface at premier prices. Borders are porous, diamonds flow easily, and armed networks are permeable and mobile. Diamonds form at great depths (over 200 km

  2. STRUCTURING OF DIAMOND FILMS USING MICROSPHERE LITHOGRAPHY

    Directory of Open Access Journals (Sweden)

    Mária Domonkos

    2014-10-01

    Full Text Available In this study, the structuring of micro- and nanocrystalline diamond thin films is demonstrated. The structuring of the diamond films is performed using the technique of microsphere lithography followed by reactive ion etching. Specifically, this paper presents a four-step fabrication process: diamond deposition (microwave plasma assisted chemical vapor deposition, mask preparation (by the standard Langmuir-Blodgett method, mask modification and diamond etching. A self-assembled monolayer of monodisperse polystyrene (PS microspheres with close-packed ordering is used as the primary template. Then the PS microspheres and the diamond films are processed in capacitively coupled radiofrequency plasma  using different plasma chemistries. This fabrication method illustrates the preparation of large arrays of periodic and homogeneous hillock-like structures. The surface morphology of processed diamond films is characterized by scanning electron microscopy and atomic force microscope. The potential applications of such diamond structures in various fields of nanotechnology are also briefly discussed.

  3. Thin diamond films for tribological applications

    International Nuclear Information System (INIS)

    Wong, M.S.; Meilunas, R.; Ong, T.P.; Chang, R.P.H.

    1989-01-01

    Diamond films have been deposited on Si, Mo and many other substrates by microwave and radio frequency plasma enhanced chemical vapor deposition. Although the adhesion between the diamond film and most of the metal substrates is poor due to residual thermal stress from the mismatch of thermal expansion coefficients, the authors have developed processes to promote the growth of uniform and continuous diamond films with enhanced adhesion to metal substrates for tribological applications. The tribological properties of these films are measured using a ring-on-block tribotester. The coefficients of friction of diamond films sliding against a 52100 steel ring under the same experimental conditions are found to be significantly different depending on the morphology, grain size and roughness of the diamond films. However, under all cases tested, it is found that for uniform and continuous diamond films with small grain size of 1-3 micrometers, the coefficient of friction of the diamond film sliding against a steel ring under lubrication of a jet of mineral oil is about 0.04

  4. CVD diamond for nuclear detection applications

    International Nuclear Information System (INIS)

    Bergonzo, P.; Brambilla, A.; Tromson, D.; Mer, C.; Guizard, B.; Marshall, R.D.; Foulon, F.

    2002-01-01

    Chemically vapour deposited (CVD) diamond is a remarkable material for the fabrication of radiation detectors. In fact, there exist several applications where other standard semiconductor detectors do not fulfil the specific requirements imposed by corrosive, hot and/or high radiation dose environments. The improvement of the electronic properties of CVD diamond has been under intensive investigations and led to the development of a few applications that are addressing specific industrial needs. Here, we report on CVD diamond-based detector developments and we describe how this material, even though of a polycrystalline nature, is readily of great interest for applications in the nuclear industry as well as for physics experiments. Improvements in the material synthesis as well as on device fabrication especially concern the synthesis of films that do not exhibit space charge build up effects which are often encountered in CVD diamond materials and that are highly detrimental for detection devices. On a pre-industrial basis, CVD diamond detectors have been fabricated for nuclear industry applications in hostile environments. Such devices can operate in harsh environments and overcome limitations encountered with the standard semiconductor materials. Of these, this paper presents devices for the monitoring of the alpha activity in corrosive nuclear waste solutions, such as those encountered in nuclear fuel assembly reprocessing facilities, as well as diamond-based thermal neutron detectors exhibiting a high neutron to gamma selectivity. All these demonstrate the effectiveness of a demanding industrial need that relies on the remarkable resilience of CVD diamond

  5. Phosphorylated nano-diamond/ Polyimide Nanocomposites

    International Nuclear Information System (INIS)

    Beyler-Çiǧil, Asli; Çakmakçi, Emrah; Kahraman, Memet Vezir

    2014-01-01

    In this study, a novel route to synthesize polyimide (PI)/phosphorylated nanodiamond films with improved thermal and mechanical properties was developed. Surface phosphorylation of nano-diamond was performed in dichloromethane. Phosphorylation dramatically enhanced the thermal stability of nano-diamond. Poly(amic acid) (PAA), which is the precursor of PI, was successfully synthesized with 3,3',4,4'-Benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-oxydianiline (4,4'-ODA) in the solution of N,N- dimethylformamide (DMF). Pure BTDA-ODA polyimide films and phosphorylated nanodiamond containing BTDA-ODA PI films were prepared. The PAA displayed good compatibility with phosphorylated nano-diamond. The morphology of the polyimide (PI)/phosphorylated nano-diamond was characterized by scanning electron microscopy (SEM). Chemical structure of polyimide and polyimide (PI)/phosphorylated nano-diamond was characterized by FTIR. SEM and FTIR results showed that the phosphorylated nano-diamond was successfully prepared. Thermal properties of the polyimide (PI)/phosphorylated nanodiamond was characterized by thermogravimetric analysis (TGA). TGA results showed that the thermal stability of (PI)/phosphorylated nano-diamond film was increased

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

    Science.gov (United States)

    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.

  7. Diamond-Based Supercapacitors: Realization and Properties.

    Science.gov (United States)

    Gao, Fang; Nebel, Christoph E

    2016-10-26

    In this Spotlight on Applications, we describe our recent progress on the fabrication of surface-enlarged boron-doped polycrystalline diamond electrodes, and evaluate their performance in supercapacitor applications. We begin with a discussion of the fabrication methods of porous diamond materials. The diamond surface enlargement starts with a top-down plasma etching method. Although the extra surface area provided by surface roughening or nanostructuring provides good outcome for sensing applications, a capacitance value <1 mF cm -2 or a surface-enlargement factor <100 fail to meet the requirement of a practical supercapacitor. Driven by the need for large surface areas, we recently focused on the tempated-growth method. We worked on both supported and free-standing porous diamond materials to enhance the areal capacitance to the "mF cm -2 " range. With our newly developed free-standing diamond paper, areal capacitance can be multiplied by stacking multilayers of the electrode material. Finally, considering the fact that there is no real diamond-based supercapacitor device up to now, we fabricated the first prototype pouch-cell device based on the free-standing diamond paper to evaluate its performance. The results reveal that the diamond paper is suitable for operation in high potential windows (up to 2.5 V) in aqueous electrolyte with a capacitance of 0.688 mF cm -2 per layer of paper (or 0.645 F g -1 ). Impedance spectroscopy revealed that the operation frequency of the device exceeds 30 Hz. Because of the large potential window and the ability to work at high frequency, the specific power of the device reached 1 × 10 5 W kg -1 . In the end, we made estimations on the future target performance of diamond supercapacitors based on the existing information.

  8. Diamond deposition on siliconized stainless steel

    International Nuclear Information System (INIS)

    Alvarez, F.; Reinoso, M.; Huck, H.; Rosenbusch, M.

    2010-01-01

    Silicon diffusion layers in AISI 304 and AISI 316 type stainless steels were investigated as an alternative to surface barrier coatings for diamond film growth. Uniform 2 μm thick silicon rich interlayers were obtained by coating the surface of the steels with silicon and performing diffusion treatments at 800 deg. C. Adherent diamond films with low sp 2 carbon content were deposited on the diffused silicon layers by a modified hot filament assisted chemical vapor deposition (HFCVD) method. Characterization of as-siliconized layers and diamond coatings was performed by energy dispersive X-ray analysis, scanning electron microscopy, X-ray diffraction and Raman spectroscopy.

  9. Physics and applications of CVD diamond

    CERN Document Server

    Koizumi, Satoshi; Nesladek, Milos

    2008-01-01

    Here, leading scientists report on why and how diamond can be optimized for applications in bioelectronic and electronics. They cover such topics as growth techniques, new and conventional doping mechanisms, superconductivity in diamond, and excitonic properties, while application aspects include quantum electronics at room temperature, biosensors as well as diamond nanocantilevers and SAWs.Written in a review style to make the topic accessible for a wider community of scientists working in interdisciplinary fields with backgrounds in physics, chemistry, biology and engineering, this is e

  10. Residual radioactivity of treated green diamonds.

    Science.gov (United States)

    Cassette, Philippe; Notari, Franck; Lépy, Marie-Christine; Caplan, Candice; Pierre, Sylvie; Hainschwang, Thomas; Fritsch, Emmanuel

    2017-08-01

    Treated green diamonds can show residual radioactivity, generally due to immersion in radium salts. We report various activity measurements on two radioactive diamonds. The activity was characterized by alpha and gamma ray spectrometry, and the radon emanation was measured by alpha counting of a frozen source. Even when no residual radium contamination can be identified, measurable alpha and high-energy beta emissions could be detected. The potential health impact of radioactive diamonds and their status with regard to the regulatory policy for radioactive products are discussed. Copyright © 2017. Published by Elsevier Ltd.

  11. Improvements to well scintillation counters

    International Nuclear Information System (INIS)

    Farukhi, M.R.; Mataraza, G.A.; Wimer, O.D.

    1977-01-01

    This invention relates to the field of ionising radiation detection. It concerns in particular scintillation detectors of the type that is commonly used in conjunction with a photomultiplier tube and that is used for monitoring radiation, for instance in the clinical measurements of isotopes. This invention enables well scintillation counters to be made, characterised by a high efficiency in measuring the thindown rate of radio-pharmaceutical solutions and to resolve the distribution of energy emanating from the radioactive source. It particularly consists in improving the uniformity of the luminous efficiency, the quality of the resolution and the efficiency whilst improving the reception of light [fr

  12. Scintillation counter based radiation dosimeter

    International Nuclear Information System (INIS)

    Shin, Jeong Hyun

    2009-02-01

    The average human exposure per year is about 240mrem which is come from Radon and human body and terrestrial and cosmic radiation and man-made source. Specially radiation exposure through air from environmental radiation sources is 80mrem/yr(= 0.01mR/hr) which come from Terrestrial and cosmic radiation. Radiation dose is defined as energy deposit/mass. There are two major methods to detect radiation. First method is the energy integration using Air equivalent material like GM counter wall material. Second method is the spectrum to dose conversion method using NaI(Tl), HPGe. These two methods are using generally to detect radiation. But these methods are expensive. So we need new radiation detection method. The research purpose is the development of economical environmental radiation dosimeter. This system consists of Plastic/Inorganic scintillator and Si photo-diode based detector and counting based circuitry. So count rate(cps) can be convert to air exposure rate(R/hr). There are three major advantages in this system. First advantages is no high voltage power supply like GM counter. Second advantage is simple electronics. Simple electronics system can be achieved by Air-equivalent scintillation detector with Al filter for the same detection efficiency vs E curve. From former two advantages, we can know the most important advantages of the this system. Third advantage is economical system. The price of typical GM counter is about $1000. But the price of our system is below $100 because of plastic scintillator and simple electronics. The role of scintillation material is emitting scintillation which is the flash of light produced in certain materials when they absorb ionizing radiation. Plastic scintillator is organic scintillator which is kind of hydrocarbons. The special point are cheap price, large size production(∼ton), moderate light output, fast light emission(ns). And the role of Al filter is equalizing counting efficiency of air and scintillator for

  13. Amorphous Diamond MEMS and Sensors

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. ULTRAFINE FLUORESCENT DIAMONDS IN NANOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Kanyuk M. I.

    2014-07-01

    Full Text Available The purpose of the work is to summarize the literature data concerning ultrafine diamonds, namely their industrial production, as well as considerable photostability and biocompatibility that promote their use in modern visualization techniques. It is shown that due to the unique physical properties, they are promising materials for using in nanotechnology in the near future. Possibility of diverse surface modification, small size and large absorption surface are the basis for their use in different approaches for drug and gene delivery into a cell. The changes in the properties of nanodiamond surface modification methods of their creation, stabilization and applications are described. It can be said that fluorescent surface-modified nanodiamonds are a promising target in various research methods that would be widely used for labeling of living cells, as well as in the processes of genes and drugs delivery into a cell.

  15. Programmable spark counter of tracks

    International Nuclear Information System (INIS)

    Denisov, A.E.; Nikolaev, V.A.; Vorobjev, I.B.

    2005-01-01

    For the purpose, a new set-the programmable all-automatic spark counter AIST-4-has been developed and manufactured. Compared to our previous automated spark counter ISTRA, which was operated by the integrated fixed program, the new set is operated completely by a personal computer. The mechanism for pressing and pulling the aluminized foil is put into action by a step motor operated by a microcontroller. The step motor turns an axle. The axle has two eccentrics. One of them moves a pressing plate up and down. The second eccentric moves the aluminized foil by steps of ∼15mm after the end of each pulse counting. One turnover of the axle corresponds to one pulse count cycle. The step motor, the high-voltage block and the pulse count block are operated by the microcontroller PIC 16C84 (Microstar). The set can be operated either manually by keys on the front panel or by a PC using dialogue windows for radon or neutron measurements (for counting of alpha or fission fragment tracks). A number of algorithms are developed: the general procedures, the automatic stopping of the pulse counting, the calibration curve, determination of the count characteristics and elimination of the short circuit in a track

  16. A low-level needle counter

    International Nuclear Information System (INIS)

    Fujita, Y.; Taguchi, Y.; Imamura, M.; Inoue, T.; Tanaka, S.

    1977-01-01

    A small end-window type gas-flow counter which has a sharpened needle (anode) against the end-window plane (cathode) was developed for low-level counting of β particles to the amount of less than one count per hour in solid sources of relatively high specific activity. The advantage of the needle counter for low-level work is that being of a conical shape the active volume as against the window area is small. The background count rate of 0.0092+-0.0005 cpm was obtained for a 10 mm dia needle counter operating in GM mode and in anticoincidence with a well-type NaI(Tl) guard crystal with massive shields. The counter design and the counter characteristics are presented in detail. The needle counter is simple in design, low-cost and stable in long time operation. (author)

  17. Astronomers debate diamonds in space

    Science.gov (United States)

    1999-04-01

    This is not the first time the intriguing carbonaceous compound has been detected in space. A peculiar elite of twelve stars are known to produce it. The star now added by ISO to this elite is one of the best representatives of this exclusive family, since it emits a very strong signal of the compound. Additionally ISO found a second new member of the group with weaker emission, and also observed with a spectral resolution never achieved before other already known stars in this class. Astronomers think these ISO results will help solve the mystery of the true nature of the compound. Their publication by two different groups, from Spain and Canada, has triggered a debate on the topic, both in astronomy institutes and in chemistry laboratories. At present, mixed teams of astrophysicists and chemists are investigating in the lab compounds whose chemical signature or "fingerprint" matches that detected by ISO. Neither diamonds nor fullerenes have ever been detected in space, but their presence has been predicted. Tiny diamonds of pre-solar origin --older than the Solar System-- have been found in meteorites, which supports the as yet unconfirmed theory of their presence in interstellar space. The fullerene molecule, made of 60 carbon atoms linked to form a sphere (hence the name "buckyball"), has also been extensively searched for in space but never found. If the carbonaceous compound detected by ISO is a fullerene or a diamond, there will be new data on the production of these industrially interesting materials. Fullerenes are being investigated as "capsules" to deliver new pharmaceuticals to the body. Diamonds are commonly used in the electronics industry and for the development of new materials; if they are formed in the dust surrounding some stars, at relatively low temperatures and conditions of low pressure, companies could learn more about the ideal physical conditions to produce them. A textbook case The latest star in which the compound has been found is

  18. Ultra-fast calculations using diamond

    NARCIS (Netherlands)

    Van Dijk, T.

    2011-01-01

    TU Delft researchers have managed to use a piece of diamond to hold four quantum bits that can be spun, flipped and entangled with each other. This is an important step towards a working quantum computer

  19. Short-range order in irradiated diamonds

    International Nuclear Information System (INIS)

    Agafonov, S.S.; Glazkov, V.P.; Nikolaenko, V.A.; Somenkov, V.A.

    2005-01-01

    Structural changes in irradiated diamond with a change in its density were studied. Natural diamond powders with average particle size from 14-20 μm to 0.5 mm, irradiated in beryllium block of the MR reactor up to a fluence of 1.51 x 10 21 were used as samples. Using the neutron-diffraction method, it has been established that, when density in irradiated diamonds varies, a transition from a diamond-like amorphous structure to a graphite-like structure occurs. The transition occurs at a density ρ ∼ 2.7-2.9 g/cm 3 and is accompanied by a sharp change in resistivity [ru

  20. Single-Crystal Diamond Nanobeam Waveguide Optomechanics

    Science.gov (United States)

    Khanaliloo, Behzad; Jayakumar, Harishankar; Hryciw, Aaron C.; Lake, David P.; Kaviani, Hamidreza; Barclay, Paul E.

    2015-10-01

    Single-crystal diamond optomechanical devices have the potential to enable fundamental studies and technologies coupling mechanical vibrations to both light and electronic quantum systems. Here, we demonstrate a single-crystal diamond optomechanical system and show that it allows excitation of diamond mechanical resonances into self-oscillations with amplitude >200 nm . The resulting internal stress field is predicted to allow driving of electron spin transitions of diamond nitrogen-vacancy centers. The mechanical resonances have a quality factor >7 ×105 and can be tuned via nonlinear frequency renormalization, while the optomechanical interface has a 150 nm bandwidth and 9.5 fm /√{Hz } sensitivity. In combination, these features make this system a promising platform for interfacing light, nanomechanics, and electron spins.

  1. Single-Crystal Diamond Nanobeam Waveguide Optomechanics

    Directory of Open Access Journals (Sweden)

    Behzad Khanaliloo

    2015-12-01

    Full Text Available Single-crystal diamond optomechanical devices have the potential to enable fundamental studies and technologies coupling mechanical vibrations to both light and electronic quantum systems. Here, we demonstrate a single-crystal diamond optomechanical system and show that it allows excitation of diamond mechanical resonances into self-oscillations with amplitude >200  nm. The resulting internal stress field is predicted to allow driving of electron spin transitions of diamond nitrogen-vacancy centers. The mechanical resonances have a quality factor >7×10^{5} and can be tuned via nonlinear frequency renormalization, while the optomechanical interface has a 150 nm bandwidth and 9.5  fm/sqrt[Hz] sensitivity. In combination, these features make this system a promising platform for interfacing light, nanomechanics, and electron spins.

  2. CVD diamond for nuclear detection applications

    CERN Document Server

    Bergonzo, P; Tromson, D; Mer, C; Guizard, B; Marshall, R D; Foulon, F

    2002-01-01

    Chemically vapour deposited (CVD) diamond is a remarkable material for the fabrication of radiation detectors. In fact, there exist several applications where other standard semiconductor detectors do not fulfil the specific requirements imposed by corrosive, hot and/or high radiation dose environments. The improvement of the electronic properties of CVD diamond has been under intensive investigations and led to the development of a few applications that are addressing specific industrial needs. Here, we report on CVD diamond-based detector developments and we describe how this material, even though of a polycrystalline nature, is readily of great interest for applications in the nuclear industry as well as for physics experiments. Improvements in the material synthesis as well as on device fabrication especially concern the synthesis of films that do not exhibit space charge build up effects which are often encountered in CVD diamond materials and that are highly detrimental for detection devices. On a pre-i...

  3. Diamond detectors for high energy physics experiments

    Science.gov (United States)

    Bäni, L.; Alexopoulos, A.; Artuso, M.; Bachmair, F.; Bartosik, M.; Beacham, J.; Beck, H.; Bellini, V.; Belyaev, V.; Bentele, B.; Berdermann, E.; Bergonzo, P.; Bes, A.; Brom, J.-M.; Bruzzi, M.; Cerv, M.; Chiodini, G.; Chren, D.; Cindro, V.; Claus, G.; Collot, J.; Cumalat, J.; Dabrowski, A.; D'Alessandro, R.; Dauvergne, D.; de Boer, W.; Dorfer, C.; Dünser, M.; Eremin, V.; Eusebi, R.; Forcolin, G.; Forneris, J.; Frais-Kölbl, H.; Gallin-Martel, L.; Gallin-Martel, M. L.; Gan, K. K.; Gastal, M.; Giroletti, C.; Goffe, M.; Goldstein, J.; Golubev, A.; Gorišek, A.; Grigoriev, E.; Grosse-Knetter, J.; Grummer, A.; Gui, B.; Guthoff, M.; Haughton, I.; Hiti, B.; Hits, D.; Hoeferkamp, M.; Hofmann, T.; Hosslet, J.; Hostachy, J.-Y.; Hügging, F.; Hutton, C.; Jansen, H.; Janssen, J.; Kagan, H.; Kanxheri, K.; Kasieczka, G.; Kass, R.; Kassel, F.; Kis, M.; Konovalov, V.; Kramberger, G.; Kuleshov, S.; Lacoste, A.; Lagomarsino, S.; Lo Giudice, A.; Lukosi, E.; Maazouzi, C.; Mandic, I.; Mathieu, C.; Menichelli, M.; Mikuž, M.; Morozzi, A.; Moss, J.; Mountain, R.; Murphy, S.; Muškinja, M.; Oh, A.; Oliviero, P.; Passeri, D.; Pernegger, H.; Perrino, R.; Picollo, F.; Pomorski, M.; Potenza, R.; Quadt, A.; Re, A.; Reichmann, M.; Riley, G.; Roe, S.; Sanz, D.; Scaringella, M.; Schaefer, D.; Schmidt, C. J.; Schnetzer, S.; Sciortino, S.; Scorzoni, A.; Seidel, S.; Servoli, L.; Smith, S.; Sopko, B.; Sopko, V.; Spagnolo, S.; Spanier, S.; Stenson, K.; Stone, R.; Sutera, C.; Tannenwald, B.; Taylor, A.; Traeger, M.; Tromson, D.; Trischuk, W.; Tuve, C.; Uplegger, L.; Velthuis, J.; Venturi, N.; Vittone, E.; Wagner, S.; Wallny, R.; Wang, J. C.; Weingarten, J.; Weiss, C.; Wengler, T.; Wermes, N.; Yamouni, M.; Zavrtanik, M.

    2018-01-01

    Beam test results of the radiation tolerance study of chemical vapour deposition (CVD) diamond against different particle species and energies is presented. We also present beam test results on the independence of signal size on incident particle rate in charged particle detectors based on un-irradiated and irradiated poly-crystalline CVD diamond over a range of particle fluxes from 2 kHz/cm2 to 10 MHz/cm2. The pulse height of the sensors was measured with readout electronics with a peaking time of 6 ns. In addition functionality of poly-crystalline CVD diamond 3D devices was demonstrated in beam tests and 3D diamond detectors are shown to be a promising technology for applications in future high luminosity experiments.

  4. Diamond Detector Technology: Status and Perspectives

    CERN Document Server

    Reichmann, M; Artuso, M; Bachmair, F; Bäni, L; Bartosik, M; Beacham, J; Beck, H; Bellini, V; Belyaev, V; Bentele, B; Berdermann, E; Bergonzo, P; Bes, A; Brom, J-M; Bruzzi, M; Cerv, M; Chiodini, G; Chren, D; Cindro, V; Claus, G; Collot, J; Cumalat, J; Dabrowski, A; D'Alessandro, R; Dauvergne, D; de Boer, W; Dorfer, C; Dünser, M; Eremin, V; Eusebi, R; Forcolin, G; Forneris, J; Frais-Kölbl, H; Gallin-Martel, L; Gallin-Martel, M L; Gan, K K; Gastal, M; Giroletti, C; Goffe, M; Goldstein, J; Golubev, A; Gorišek, A; Grigoriev, E; Grosse-Knetter, J; Grummer, A; Gui, B; Guthoff, M; Haughton, I; Hiti, B; Hits, D; Hoeferkamp, M; Hofmann, T; Hosslet, J; Hostachy, J-Y; Hügging, F; Hutton, C; Jansen, H; Janssen, J; Kagan, H; Kanxheri, K; Kasieczka, G; Kass, R; Kassel, F; Kis, M; Konovalov, V; Kramberger, G; Kuleshov, S; Lacoste, A; Lagomarsino, S; Lo Giudice, A; Lukosi, E; Maazouzi, C; Mandic, I; Mathieu, C; Menichelli, M; Mikuž, M; Morozzi, A; Moss, J; Mountain, R; Murphy, S; Muškinja, M; Oh, A; Oliviero, P; Passeri, D; Pernegger, H; Perrino, R; Picollo, F; Pomorski, M; Potenza, R; Quadt, A; Re, A; Riley, G; Roe, S; Sanz-Becerra, D A; Scaringella, M; Schaefer, D; Schmidt, C J; Schnetzer, S; Sciortino, S; Scorzoni, A; Seidel, S; Servoli, L; Smith, S; Sopko, B; Sopko, V; Spagnolo, S; Spanier, S; Stenson, K; Stone, R; Sutera, C; Tannenwald, B; Taylor, A; Traeger, M; Tromson, D; Trischuk, W; Tuve, C; Uplegger, L; Velthuis, J; Venturi, N; Vittone, E; Wagner, S; Wallny, R; Wang, J C; Weingarten, J; Weiss, C; Wengler, T; Wermes, N; Yamouni, M; Zavrtanik, M

    2018-01-01

    The planned upgrade of the LHC to the High-Luminosity-LHC will push the luminosity limits above the original design values. Since the current detectors will not be able to cope with this environment ATLAS and CMS are doing research to find more radiation tolerant technologies for their innermost tracking layers. Chemical Vapour Deposition (CVD) diamond is an excellent candidate for this purpose. Detectors out of this material are already established in the highest irradiation regimes for the beam condition monitors at LHC. The RD42 collaboration is leading an effort to use CVD diamonds also as sensor material for the future tracking detectors. The signal behaviour of highly irradiated diamonds is presented as well as the recent study of the signal dependence on incident particle flux. There is also a recent development towards 3D detectors and especially 3D detectors with a pixel readout based on diamond sensors.

  5. Modified diamond dies for laser applications

    Energy Technology Data Exchange (ETDEWEB)

    McWilliams, R.A.

    1978-06-21

    A modified wire drawing die for spatial filtering techniques is described. It was designed for use in high power laser systems. The diamond aperture is capable of enduring high intensity laser frequency without damaging the laser beam profile. The diamond is mounted at the beam focus in a vacuum of 1 x 10/sup -5/ Torr. The vacuum prevents plasma forming at the diamond aperture, thus enabling the beam to pass through without damaging the holder or aperture. The spatial filters are fitted with a manipulator that has three electronic stepping motors, can position the aperture in three orthogonal directions, and is capable of 3.2 ..mu..m resolution. Shiva laser system is using 105 diamond apertures for shaping the High Energy Laser Beam.

  6. The DIAMOND Model of Peace Support Operations

    National Research Council Canada - National Science Library

    Bailey, Peter

    2005-01-01

    DIAMOND (Diplomatic And Military Operations in a Non-warfighting Domain) is a high-level stochastic simulation developed at Dstl as a key centerpiece within the Peace Support Operations (PSO) 'modelling jigsaw...

  7. Counter Traction Makes Endoscopic Submucosal Dissection Easier

    OpenAIRE

    Oyama, Tsuneo

    2012-01-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable co...

  8. Crate counter for normal operating loss

    International Nuclear Information System (INIS)

    Harlan, R.A.

    A lithium-loaded zinc sulfide scintillation counter to closely assay plutonium in waste packaged in 1.3 by 1.3 by 2.13m crates was built. In addition to assays for normal operating loss accounting, the counter will allow safeguards verification immediately before shipment of the crates for burial. The counter should detect approximately 10 g of plutonium in 1000 kg of waste

  9. Dosimetry in radiotherapy with natural diamond detectors

    International Nuclear Information System (INIS)

    De Angelis, C.; Onori, S.; Pacilio, M.; Cirrone, G.A.P.; Cuttone, G.; Raffaele, L.; Bucciolini, M.; Mazzocchi, S.

    2002-01-01

    There is wide interest in the use of diamond detectors for dosimetry in radiotherapy mainly because of the small dimensions, radiation hardness, nearly tissue equivalence of sensitive material and capability to deliver the dosimetric response 'on line'. In order to assess the dosimetric properties of PTW Riga diamond detectors type 60003, experiments were performed in conventional (high energy photon and electron) therapy beams as well as in proton therapy beams. The main detector features investigated were reproducibility of response, dose-signal relationship, temperature dependence, dose-rate dependence, energy dependence and angular dependence. High energy photons (6-25 MV) and electrons (6-22 MeV), available at the Radiotherapy Department of the Florence University, were used for investigating the general properties. Two different PTW diamond detectors of the same type were used to evidence inter-sample differences. The beam quality dependence of the detector response is probably the most critical point and this statement is of particular relevance for proton dosimetry since the proton LET changes with depth in the medium. Mainly because of the little information available on detector sensitivity variations with beam energy, the use of diamonds for clinical proton dosimetry is not widespread. In two recent papers a sensitivity dependence on proton energy of a natural PTW diamond detector has been reported. Due to the necessity to characterise each diamond detector individually the PTW Riga natural diamond detector in operation at the LNS-INFN, Catania, Italy was tested with the local proton beam line. This experiment is of main concern because this proton beam, produced by a superconducting cyclotron and used for ocular melanoma treatment, is available only since 2001 (CATANA beam). The first patient has been treated in February 2002. Proton irradiations were performed with non modulated and modulated 62 MeV beams. Attention was focused on diamond sensitivity

  10. Polycrystalline Diamond Schottky Diodes and Their Applications.

    Science.gov (United States)

    Zhao, Ganming

    In this work, four-hot-filament CVD techniques for in situ boron doped diamond synthesis on silicon substrates were extensively studied. A novel tungsten filament shape and arrangement used to obtain large-area, uniform, boron doped polycrystalline diamond thin films. Both the experimental results and radiative heat transfer analysis showed that this technique improved the uniformity of the substrate temperature. XRD, Raman and SEM studies indicate that large area, uniform, high quality polycrystalline diamond films were obtained. Schottky diodes were fabricated by either sputter deposition of silver or thermal evaporation of aluminum or gold, on boron doped diamond thin films. High forward current density and a high forward-to-reverse current ratio were exhibited by silver on diamond Schottky diodes. Schottky barrier heights and the majority carrier concentrations of both aluminum and gold contacted diodes were determined from the C-V measurements. Furthermore, a novel theoretical C-V-f analysis of deep level boron doped diamond Schottky diodes was performed. The analytical results agree well with the experimental results. Compressive stress was found to have a large effect on the forward biased I-V characteristics of the diamond Schottky diodes, whereas the effect on the reverse biased characteristics was relatively small. The stress effect on the forward biased diamond Schottky diode was attributed to piezojunction and piezoresistance effects. The measured force sensitivity of the diode was as high as 0.75 V/N at 1 mA forward bias. This result shows that CVD diamond device has potential for mechanical transducer applications. The quantitative photoresponse characteristics of the diodes were studied in the spectral range of 300 -1050 nm. Semi-transparent gold contacts were used for better photoresponse. Quantum efficiency as high as 50% was obtained at 500 nm, when a reverse bias of over 1 volt was applied. The Schottky barrier heights between either gold or

  11. Growth and optical spectroscopy of synthetic diamonds

    International Nuclear Information System (INIS)

    Mudryj, A.V.; Larionova, T.P.; Shakin, I.A.; Gysakov, G.A.; Dubrov, G.A.; Tikhonov, V.V.

    2003-01-01

    It is studied the growth and optical properties of synthetic diamonds, which may be used for detection of ionizing radiation, optical windows, heat removal, ultraviolet and thermo sensors, optoelectronic devices. Optical properties of diamonds (grown in different technological conditions) were studied in temperature range 78 - 300 K by means of measuring transmission in spectral band 0.2 - 25 μm, photoluminescence and registration of luminescence excitation spectra in spectral band 0.2 - 2 μm

  12. Long-term data storage in diamond

    OpenAIRE

    Dhomkar, Siddharth; Henshaw, Jacob; Jayakumar, Harishankar; Meriles, Carlos A.

    2016-01-01

    The negatively charged nitrogen vacancy (NV?) center in diamond is the focus of widespread attention for applications ranging from quantum information processing to nanoscale metrology. Although most work so far has focused on the NV? optical and spin properties, control of the charge state promises complementary opportunities. One intriguing possibility is the long-term storage of information, a notion we hereby introduce using NV-rich, type 1b diamond. As a proof of principle, we use multic...

  13. Diamond nanostructured devices for chemical sensing applications

    OpenAIRE

    Ahmad, R. K.

    2011-01-01

    Research in the area of CVD single crystal diamond plates of which only recently has been made commercially available saw significant advancements during the last decade. In parallel to that, detonation nanodiamond (DND) particles also now widely made accessible for requisition are provoking a lot of scientific investigations. The remarkable properties of diamond including its extreme hardness, low coefficient of friction, chemical inertness, biocompatibility, high thermal c...

  14. Diamond carbon sources: a comparison of carbon isotope models

    International Nuclear Information System (INIS)

    Kirkley, M.B.; Otter, M.L.; Gurney, J.J.; Hill, S.J.

    1990-01-01

    The carbon isotope compositions of approximately 500 inclusion-bearing diamonds have been determined in the past decade. 98 percent of these diamonds readily fall into two broad categories on the basis of their inclusion mineralogies and compositions. These categories are peridotitic diamonds and eclogitic diamonds. Most peridotitic diamonds have δ 13 C values between -10 and -1 permil, whereas eclogitic diamonds have δ 13 C values between -28 and +2 permil. Peridotitic diamonds may represent primordial carbon, however, it is proposed that initially inhomogeneous δ 13 C values were subsequently homogenized, e.g. during melting and convection that is postulated to have occurred during the first billion years of the earth's existence. If this is the case, then the wider range of δ 13 C values exhibited by eclogitic diamonds requires a different explanation. Both the fractionation model and the subduction model can account for the range of observed δ 13 C values in eclogitic diamonds. 16 refs., 2 figs

  15. Graphitization of diamond with a metallic coating on ferritic matrix

    International Nuclear Information System (INIS)

    Cabral, Stenio Cavalier; Oliveira, Hellen Cristine Prata de; Filgueira, Marcello

    2010-01-01

    Iron is a strong catalyst of graphitization of diamonds. This graphitization occurs mainly during the processing of composites - conventional sintering or hot pressing, and during cutting operations. Aiming to avoid or minimize this deleterious effect, there is increasing use of diamond coated with metallic materials in the production of diamond tools processed via powder metallurgy. This work studies the influence of Fe on diamond graphitization diamond-coated Ti after mixing of Fe-diamonds, hot pressing parameters were performed with 3 minutes/35MPa/900 deg C - this is the condition of pressing hot used in industry for production of diamond tools. Microstructural features were observed by SEM, diffusion of Fe in diamond was studied by EDS. Graphitization was analyzed by X-ray diffraction and Raman spectroscopy. It was found that Fe not activate graphitization on the diamond under the conditions of hot pressing. (author)

  16. The 'miniskirt' counter array at CDF II

    International Nuclear Information System (INIS)

    Artikov, A.; Budagov, Yu.; Bellettini, G.

    2002-01-01

    Muon detection is fundamental to many of the interesting analyses at CDF II. For more efficient muon registration in Run II it was decided to increase geometrical coverage. The so-called 'miniskirt' counters are part of this upgrade. The original design parameters of the 'miniskirt' and mixed 'miniskirt' scintillation counters for the CDF Muon System are presented. The modifications, testing and installation of these counters within the CDF Upgrade Project are described in detail. The timing characteristics of mixed 'miniskirt' counters are also investigated using cosmic muons. The measurements show that the time resolution does not exceed 2.2 ns

  17. Detection and analysis of diamond fingerprinting feature and its application

    Energy Technology Data Exchange (ETDEWEB)

    Li Xin; Huang Guoliang; Li Qiang; Chen Shengyi, E-mail: tshgl@tsinghua.edu.cn [Department of Biomedical Engineering, the School of Medicine, Tsinghua University, Beijing, 100084 (China)

    2011-01-01

    Before becoming a jewelry diamonds need to be carved artistically with some special geometric features as the structure of the polyhedron. There are subtle differences in the structure of this polyhedron in each diamond. With the spatial frequency spectrum analysis of diamond surface structure, we can obtain the diamond fingerprint information which represents the 'Diamond ID' and has good specificity. Based on the optical Fourier Transform spatial spectrum analysis, the fingerprinting identification of surface structure of diamond in spatial frequency domain was studied in this paper. We constructed both the completely coherent diamond fingerprinting detection system illuminated by laser and the partially coherent diamond fingerprinting detection system illuminated by led, and analyzed the effect of the coherence of light source to the diamond fingerprinting feature. We studied rotation invariance and translation invariance of the diamond fingerprinting and verified the feasibility of real-time and accurate identification of diamond fingerprint. With the profit of this work, we can provide customs, jewelers and consumers with a real-time and reliable diamonds identification instrument, which will curb diamond smuggling, theft and other crimes, and ensure the healthy development of the diamond industry.

  18. Diamond growth in oxygen-acetylene flame

    International Nuclear Information System (INIS)

    Haga, Mario S.; Nagai, Y. Ernesto; Suzuki, Carlos K.

    1995-01-01

    What was supposed to be a laboratory curiosity in the 80's, in recent years the low pressure process for the production of man-made diamond turned out to be a major target for research and development of many high-tech companies. The main reason for such an interest stems on the possibility of coating many materials with a diamond film possessing the same amazing properties of the bulk natural diamond. Polycrystalline diamond film has been deposited on Mo substrate by using oxygen-acetylene flame of a welding torch. The substrate temperature has been held constant about 700 d eg C by means of a water cooled mount designed properly. Precision flowmeters have been used to control the flow ratio oxygen/acetylene, a key parameter for the success in diamond growth. Diamond has been detected by X-ray diffraction, a fast foolproof technique for crystal identification. Another method of analysis often used in Raman spectroscopy, which is able to exhibit amorphous structure besides crystalline phase. (author)

  19. CVD diamond deposition onto dental burs

    International Nuclear Information System (INIS)

    Ali, N.; Sein, H.

    2001-01-01

    A hot-filament chemical vapor deposition (HFCVD) system has been modified to enable non-planar substrates, such as metallic wires and dental burs, to be uniformly coated with thin polycrystalline diamond films. Initially, diamond deposition was carried out on titanium and tantalum wires in order to test and optimize the system. High growth rates of the order of approx. 8 /hr were obtained when depositing diamond on titanium wires using the vertical filament arrangement. However, lower growth rates of the order of 4-5meu m/hr were obtained with diamond deposition on tantalum wires. To extend the work towards a practical biomedical application tungsten carbide dental burs were coated with diamond films. The as-grown films were found to be polycrystalline and uniform over the cutting tip. Finally, the costs relating to diamond CVD onto dental burs have been presented in this paper. The costs relating to coating different number of burs at a time and the effect of film thickness on costs have been included in this investigation. (author)

  20. Development of CVD diamond radiation detectors

    CERN Document Server

    Adam, W; Berdermann, E; Bogani, F; Borchi, E; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fisch, D; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E A; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Knöpfle, K T; Krammer, Manfred; Manfredi, P F; Meier, D; Mishina, M; Le Normand, F; Pan, L S; Pernegger, H; Pernicka, Manfred; Pirollo, S; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Tapper, R J; Tesarek, R J; Thomson, G B; Trawick, M L; Trischuk, W; Turchetta, R; Walsh, A M; Wedenig, R; Weilhammer, Peter; Ziock, H J; Zoeller, M M

    1998-01-01

    Diamond is a nearly ideal material for detecting ionizing radiation. Its outstanding radiation hardness, fast charge collection and low leakage current allow a diamond detector to be used in high ra diation, high temperature and in aggressive chemical media. We have constructed charged particle detectors using high quality CVD diamond. Characterization of the diamond samples and various detect ors are presented in terms of collection distance, $d=\\mu E \\tau$, the average distance electron-hole pairs move apart under the influence of an electric field, where $\\mu$ is the sum of carrier mo bilities, $E$ is the applied electric field, and $\\tau$ is the mobility weighted carrier lifetime. Over the last two years the collection distance increased from $\\sim$ 75 $\\mu$m to over 200 $\\mu$ m. With this high quality CVD diamond a series of micro-strip and pixel particle detectors have been constructed. These devices were tested to determine their position resolution and signal to n oise performance. Diamond detectors w...

  1. Boron doped diamond electrode for the wastewater treatment

    International Nuclear Information System (INIS)

    Quiroz Alfaro, Marco Antonio; Ferro, Sergio; Martinez-Huitle, Carlos Alberto; Vong, Yunny Meas

    2006-01-01

    Electrochemical studies of diamond were started more than fifteen years ago with the first paper on diamond electrochemistry published by Pleskov. After that, work started in Japan, United States of America, France, Switzerland and other countries. Over the last few years, the number of publications has increased considerably. Diamond films have been the subject of applications and fundamental research in electrochemistry, opening up a new branch known as the electrochemistry of diamond electrodes. Here, we first present a brief history and the process of diamond film synthesis. The principal objective of this work is to summarize the most important results in the electrochemical oxidation using diamond electrodes. (author)

  2. Optimizing biosensing properties on undecylenic Acid-functionalized diamond.

    Science.gov (United States)

    Zhong, Yu Lin; Chong, Kwok Feng; May, Paul W; Chen, Zhi-Kuan; Loh, Kian Ping

    2007-05-08

    The optimization of biosensing efficiency on a diamond platform depends on the successful coupling of biomolecules on the surface, and also on effective signal transduction in the biorecognition events. In terms of biofunctionalization of diamond surfaces, surface electrochemical studies of diamond modified with undecylenic acid (UA), with and without headgroup protection, were performed. The direct photochemical coupling method employing UA was found to impart a higher density of carboxylic acid groups on the diamond surface compared to that using trifluoroethyl undecenoate (TFEU) as the protecting group during the coupling process. Non-faradic impedimetric DNA sensing revealed that lightly doped diamond gives better signal transduction sensitivity compared to highly doped diamond.

  3. Boron doped diamond electrode for the wastewater treatment

    Directory of Open Access Journals (Sweden)

    Alfaro Marco Antonio Quiroz

    2006-01-01

    Full Text Available Electrochemical studies of diamond were started more than fifteen years ago with the first paper on diamond electrochemistry published by Pleskov. After that, work started in Japan, United States of America, France, Switzerland and other countries. Over the last few years, the number of publications has increased considerably. Diamond films have been the subject of applications and fundamental research in electrochemistry, opening up a new branch known as the electrochemistry of diamond electrodes. Here, we first present a brief history and the process of diamond film synthesis. The principal objective of this work is to summarize the most important results in the electrochemical oxidation using diamond electrodes.

  4. Recognition of diamond grains on surface of fine diamond grinding wheel

    Institute of Scientific and Technical Information of China (English)

    Fengwei HUO; Zhuji JIN; Renke KANG; Dongming GUO; Chun YANG

    2008-01-01

    The accurate evaluation of grinding wheel sur-face topography, which is necessary for the investigation of the grinding principle, optimism, modeling, and simu-lation of a grinding process, significantly depends on the accurate recognition of abrasive grains from the measured wheel surface. A detailed analysis of the grain size distri-bution characteristics and grain profile wavelength of the fine diamond grinding wheel used for ultra-precision grinding is presented. The requirements of the spatial sampling interval and sampling area for instruments to measure the surface topography of a diamond grinding wheel are discussed. To recognize diamond grains, digital filtering is used to eliminate the high frequency disturb-ance from the measured 3D digital surface of the grinding wheel, the geometric features of diamond grains are then extracted from the filtered 3D digital surface, and a method based on the grain profile frequency characteris-tics, diamond grain curvature, and distance between two adjacent diamond grains is proposed. A 3D surface pro-filer based on scanning white light interferometry is used to measure the 3D surface topography of a #3000 mesh resin bonded diamond grinding wheel, and the diamond grains are then recognized from the 3D digital surface. The experimental result shows that the proposed method is reasonable and effective.

  5. Toward deep blue nano hope diamonds: heavily boron-doped diamond nanoparticles.

    Science.gov (United States)

    Heyer, Steffen; Janssen, Wiebke; Turner, Stuart; Lu, Ying-Gang; Yeap, Weng Siang; Verbeeck, Jo; Haenen, Ken; Krueger, Anke

    2014-06-24

    The production of boron-doped diamond nanoparticles enables the application of this material for a broad range of fields, such as electrochemistry, thermal management, and fundamental superconductivity research. Here we present the production of highly boron-doped diamond nanoparticles using boron-doped CVD diamond films as a starting material. In a multistep milling process followed by purification and surface oxidation we obtained diamond nanoparticles of 10-60 nm with a boron content of approximately 2.3 × 10(21) cm(-3). Aberration-corrected HRTEM reveals the presence of defects within individual diamond grains, as well as a very thin nondiamond carbon layer at the particle surface. The boron K-edge electron energy-loss near-edge fine structure demonstrates that the B atoms are tetrahedrally embedded into the diamond lattice. The boron-doped diamond nanoparticles have been used to nucleate growth of a boron-doped diamond film by CVD that does not contain an insulating seeding layer.

  6. Numerical model of thyroid counter

    Directory of Open Access Journals (Sweden)

    Szuchta Maciej

    2016-03-01

    Full Text Available The aim of this study was to develop a numerical model of spectrometric thyroid counter, which is used for the measurements of internal contamination by in vivo method. The modeled detector is used for a routine internal exposure monitoring procedure in the Radiation Protection Measurements Laboratory of National Centre for Nuclear Research (NCBJ. This procedure may also be used for monitoring of occupationally exposed nuclear medicine personnel. The developed model was prepared using Monte Carlo code FLUKA 2011 ver. 2b.6 Apr-14 and FLAIR ver. 1.2-5 interface. It contains a scintillation NaI(Tl detector, the collimator and the thyroid water phantom with a reference source of iodine 131I. The geometry of the model was designed and a gamma energy spectrum of iodine 131I deposited in the detector was calculated.

  7. Evaluation of waste crate counter

    International Nuclear Information System (INIS)

    Wachter, J.R.; Shaw, S.W.

    1994-01-01

    A novel nondestructive measurement system has been developed to perform combined gamma-ray, passive neutron, and active neutron analyses of radioactive waste packaged in large crates. The system will be used to examine low level and transuranic waste at the Waste Receiving and Processing facility at Westinghouse-Hanford Corp. Prior to delivery of the system, an extensive evaluation of its performance characteristics will be conducted. The evaluation is to include an assessment of the mechanical properties of the system, gamma-ray attenuation correction algorithms, instrument response as a function of source positions, performance of the high resolution gamma-ray detector for ''hot spot'' and isotopic analyses, active and passive neutron counter response, instrument sensitivity, matrix effects, and packaging effects. This report will discuss the findings of the evaluation program, to date, and indicate future directions for the program

  8. Scintillation counter: photomultiplier tube alignment

    International Nuclear Information System (INIS)

    Olson, R.E.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into the sample receiving zone. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (auth)

  9. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  10. Status and applications of diamond and diamond-like materials: An emerging technology

    Science.gov (United States)

    1990-01-01

    Recent discoveries that make possible the growth of crystalline diamond by chemical vapor deposition offer the potential for a wide variety of new applications. This report takes a broad look at the state of the technology following from these discoveries in relation to other allied materials, such as high-pressure diamond and cubic boron nitride. Most of the potential defense, space, and commercial applications are related to diamond's hardness, but some utilize other aspects such as optical or electronic properties. The growth processes are reviewed, and techniques for characterizing the resulting materials' properties are discussed. Crystalline diamond is emphasized, but other diamond-like materials (silicon carbide, amorphous carbon containing hydrogen) are also examined. Scientific, technical, and economic problem areas that could impede the rapid exploitation of these materials are identified. Recommendations are presented covering broad areas of research and development.

  11. Diamond growth on an array of seeds: The revolution of diamond production

    Energy Technology Data Exchange (ETDEWEB)

    Sung, James C. [KINIK Company, 64, Chung-San Rd., Ying-Kuo, Taipei Hsien 239, Taiwan (China) and National Taiwan University, Taipei 106, Taiwan (China) and National Taipei University of Technology, Taipei 106, Taiwan (China)]. E-mail: sung@kinik.com.tw; Sung, Michael [Massachusetts Institute of Technology, Cambridge, MA (United States); Sung, Emily [Johnson and Johnson, Freemont, CA (United States)

    2006-03-01

    The consumption of saw diamond grits is a measure of a nation's constructional activities. The per capita consumption for the world is about 0.7 carats in 2004, and in China, about 3 carats. The manufacture of large saw diamond grits requires stringent control of pressure and temperature that only a few companies can master. However, with the implementation of a novel diamond seeding technology, large saw diamond grits of extreme quality can be mass produced. With this breakthrough, the prices of saw grit will plummet in the near future that should benefit the constructional industry worldwide. Moreover, electronic or thermal grade of large diamond crystals may be produced for applications in semiconductor, electronic or optical industry.

  12. Diamond growth on an array of seeds: The revolution of diamond production

    International Nuclear Information System (INIS)

    Sung, James C.; Sung, Michael; Sung, Emily

    2006-01-01

    The consumption of saw diamond grits is a measure of a nation's constructional activities. The per capita consumption for the world is about 0.7 carats in 2004, and in China, about 3 carats. The manufacture of large saw diamond grits requires stringent control of pressure and temperature that only a few companies can master. However, with the implementation of a novel diamond seeding technology, large saw diamond grits of extreme quality can be mass produced. With this breakthrough, the prices of saw grit will plummet in the near future that should benefit the constructional industry worldwide. Moreover, electronic or thermal grade of large diamond crystals may be produced for applications in semiconductor, electronic or optical industry

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

    Science.gov (United States)

    Holcombe, Cressie E.; Seals, Roland D.; Price, R. Eugene

    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.

  14. On generating counter-rotating streamwise vortices

    KAUST Repository

    Winoto, S H

    2015-09-23

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  15. Charged particle identification: Cherenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Etkin, A.; Kostoulas, I.; Leith, D.W.G.S.; Thun, R.

    1977-01-01

    A brief summary is given of a study of Cherenkov counters for ISABELLE. The study was certainy not exhaustive and was meant primarily to suggest future detector development. A substantial research effort is needed in order to insure that Cherenkov counters utilizing photoionization are fully exploited

  16. Development of photocathodes for gas counters

    International Nuclear Information System (INIS)

    Chalot, J.F.

    1982-03-01

    A lot of ways of physics needs the development of high sensibility imaging devices with large sensitive surface. The problems brought by the building of such devices may be solved by the use of gaz counters. But we must sensitize these counters to low energy photons ( [fr

  17. On generating counter-rotating streamwise vortices

    KAUST Repository

    Winoto, S H; Mitsudharmadi, Hatsari; Budiman, A C; Hasheminejad, S M; Nadesan, T; Tandiono; Low, H T; Lee, T S

    2015-01-01

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  18. Optical studies of high quality synthetic diamond

    International Nuclear Information System (INIS)

    Sharp, S.J.

    1999-01-01

    This thesis is concerned with the study of fundamental and defect induced optical properties of synthetic diamond grown using high pressure, high temperature (HPHT) synthesis or chemical vapour deposition (CVD). The primary technique used for investigation is cathodoluminescence (including imaging and decay-time measurements) in addition to other forms of optical spectroscopy. This thesis is timely in that the crystallinity and purity of synthetic diamond has increased ten fold over the last few years. The diamond exciton emission, which is easily quenched by the presence of defects, is studied in high quality samples in detail. In addition the ability now exists to engineer the isotopic content of synthetic diamond to a high degree of accuracy. The experimental chapters are divided as follows: Chapter 2: High resolution, low temperature spectra reveal a splitting of the free-exciton phonon recombination emission peaks and the bound-exciton zero phonon line. Included are measurements of the variation in intensity and decay-time as a function of temperature. Chapter 3: The shift in energy of the phonon-assisted free-exciton phonon replicas with isotopic content has been measured. The shift is in agreement with the results of interatomic force model for phonon scattering due to isotope disorder. Chapter 4: A study of the shift in energy with isotopic content of the diamond of the GR1 band due to the neutral vacancy has allowed a verification of the theoretical predictions due to the Jahn Teller effect. Chapter 5: The spatial distribution of the free-exciton luminescence is studied in HPHT synthetic and CVD diamond. A variation in intensity with distance from the surface is interpreted as a significant non-radiative loss of excitons to the surface. Chapter 6: The decay-times of all known self-interstitial related centres have been measured in order to calculate the concentration of these centres present in electron irradiated diamond. (author)

  19. Counter traction makes endoscopic submucosal dissection easier.

    Science.gov (United States)

    Oyama, Tsuneo

    2012-11-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.

  20. Aerogel Cherenkov Counters of the KEDR Detector

    CERN Document Server

    Ovtin, I V; Barnyakov, M Y; Bobrovnikov, V S; Buzykaev, A R; Danilyuk, A F; Katcin, A A; Kononov, S A; Kravchenko, E A; Kuyanov, I A; Onuchin, A P; Rodiakin, V A

    2017-01-01

    The particle identification system of the KEDR detector is based on aerogel threshold Cherenkov counters called ASHIPH counters. The system consists of 160 counters arranged in two layers. An event reconstruction program for the ASHIPH system was developed. The position of each counter relative to the tracking system was determined using cosmic muons and Bhabha events. The geometric efficiency of the ASHIPH system was verified with Bhabha events. The efficiency of relativistic particle detection was measured with cosmic muons. A π/K separation of 4δ in the momentum range 0.95 −1.45 GeV/c was confirmed. A simulation program for the ASHIPH counters has been developed.

  1. The Diamond machine protection system

    International Nuclear Information System (INIS)

    Heron, M.T.; Lay, S.; Chernousko, Y.; Hamadyk, P.; Rotolo, N.

    2012-01-01

    The Diamond Light Source Machine Protection System (MPS) manages the hazards from high power photon beams and other hazards to ensure equipment protection on the booster synchrotron and storage ring. The system has a shutdown requirement, on a beam mis-steer of under 1 msec and has to manage in excess of a thousand interlocks. This is realised using a combination of bespoke hardware and programmable logic controllers. The MPS monitors a large number of interlock signals from diagnostics instrumentation, vacuum instrumentation, photon front ends and plant monitoring subsystems. Based on logic it can then remove the source of the energy to ensure protection of equipment. Depending on requirements, interlocks are managed on a Local or a Global basis. The Global system is structured as two layers, and supports fast- and slow-response-time interlock requirements. A Global MPS module takes the interlock permits for a given interlock circuit from each of the cells of the accelerator, and, subject to all interlocks being good, produces a permit to operate the source of energy: the RF amplifier for vessel protection and the PSU for magnet protection. The Local MPS module takes fast Interlock inputs from one cell of the Storage Ring or one quadrant of the Booster. Fast interlocks are those that must drop the beam in under 400 μsec (the maximum speed of the interlock) in the event of failure. EPIC provides the user interface to the MPS system

  2. Kankan diamonds (Guinea) III: δ13C and nitrogen characteristics of deep diamonds

    Science.gov (United States)

    Stachel, T.; Harris, J. W.; Aulbach, S.; Deines, P.

    Diamonds from the Kankan area in Guinea formed over a large depth profile beginning within the cratonic mantle lithosphere and extending through the asthenosphere and transition zone into the lower mantle. The carbon isotopic composition, the concentration of nitrogen impurities and the nitrogen aggregation level of diamonds representing this entire depth range have been determined. Peridotitic and eclogitic diamonds of lithospheric origin from Kankan have carbon isotopic compositions (δ13C: peridotitic -5.4 to -2.2‰ eclogitic -19.7 to -0.7‰) and nitrogen characteristics (N: peridotitic 17-648 atomic ppm; eclogitic 0-1,313 atomic ppm; aggregation from IaA to IaB) which are generally typical for diamonds of these two suites worldwide. Geothermobarometry of peridotitic and eclogitic inclusion parageneses (worldwide sources) indicates that both suites formed under very similar conditions within the cratonic lithosphere, which is not consistent with a derivation of diamonds with light carbon isotopic composition from subducted organic matter within subducting oceanic slabs. Diamonds containing majorite garnet inclusions fall to the isotopically heavy side (δ13C: -3.1‰ to +0.9‰) of the worldwide diamond population. Nitrogen contents are low (0-126 atomic ppm) and one of the two nitrogen-bearing diamonds shows such a low level of nitrogen aggregation (30% B-centre) that it cannot have been exposed to ambient temperatures of the transition zone (>=1,400 °C) for more than 0.2 Ma. This suggests rapid upward transport and formation of some Kankan diamonds pene-contemporaneous to Cretaceous kimberlite activity. Similar to these diamonds from the asthenosphere and the transition zone, lower mantle diamonds show a small shift towards isotopic heavy compositions (-6.6 to -0.5‰, mode at -3.5‰). As already observed for other mines, the nitrogen contents of lower mantle diamonds were below detection (using FTIRS). The mutual shift of sublithospheric diamonds towards

  3. Critical components for diamond-based quantum coherent devices

    International Nuclear Information System (INIS)

    Greentree, Andrew D; Olivero, Paolo; Draganski, Martin; Trajkov, Elizabeth; Rabeau, James R; Reichart, Patrick; Gibson, Brant C; Rubanov, Sergey; Huntington, Shane T; Jamieson, David N; Prawer, Steven

    2006-01-01

    The necessary elements for practical devices exploiting quantum coherence in diamond materials are summarized, and progress towards their realization documented. A brief review of future prospects for diamond-based devices is also provided

  4. Prospects for the synthesis of large single-crystal diamonds

    International Nuclear Information System (INIS)

    Khmelnitskiy, R A

    2015-01-01

    The unique properties of diamond have stimulated the study of and search for its applications in many fields, including optics, optoelectronics, electronics, biology, and electrochemistry. Whereas chemical vapor deposition allows the growth of polycrystalline diamond plates more than 200 mm in diameter, most current diamond application technologies require large-size (25 mm and more) single-crystal diamond substrates or films suitable for the photolithography process. This is quite a challenge, because the largest diamond crystals currently available are 10 mm or less in size. This review examines three promising approaches to fabricating large-size diamond single crystals: growing large-size single crystals, the deposition of heteroepitaxial diamond films on single-crystal substrates, and the preparation of composite diamond substrates. (reviews of topical problems)

  5. Architecting boron nanostructure on the diamond particle surface

    International Nuclear Information System (INIS)

    Bai, H.; Dai, D.; Yu, J.H.; Nishimura, K.; Sasaoka, S.; Jiang, N.

    2014-01-01

    The present study provides an efficient approach for nano-functionalization of diamond powders. Boron nanostructure can be grown on diamond particle entire surface by a simple heat-treatment process. After treatment, various boron nanoforms were grown on the diamond particle surface at different processing temperature. High-density boron nanowires (BNWs) grow on the diamond particle entire surface at 1333 K, while nanopillars cover diamond powders when the heat treatment process is performed at 1393 K. The influence of the pretreatment temperature on the microstructure and thermal conductivity of Cu/diamond composites were investigated. Cu/diamond composites with high thermal conductivity of 670 W (m K) −1 was obtained, which was achieved by the formation of large number of nanowires and nanopillars on the diamond particle surface.

  6. Development of diamond coated tool and its performance in ...

    Indian Academy of Sciences (India)

    Unknown

    Mechanical Engineering Department, Indian Institute of Technology, Kharagpur 721 302, India ... chemical inertness of diamond coating towards the work material, did not show any .... CVD diamond coated carbide tools, Ph D Thesis, Indian.

  7. Comparative evaluation of CVD diamond technologies

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, T.R. [General Electric Corporate Research & Development Center, Schenectady, NY (United States)

    1993-01-01

    Chemical vapor deposition (CVD) of diamonds occurs from hydrogen-hydrocarbon gas mixtures in the presence of atomic hydrogen at subatmospheric pressures. Most CVD methods are based on different means of generating and transporting atomic hydrogen in a particular system. Evaluation of these different techniques involves their capital costs, material costs, energy costs, labor costs and the type and quality of diamond that they produce. Currently, there is no universal agreement on which is the best technique and technique selection has been largely driven by the professional background of the user as well as the particular application of interest. This article discusses the criteria for evaluating a process for low-pressure deposition of diamond. Next, a brief history of low-pressure diamond synthesis is reviewed. Several specific processes are addressed, including the hot filament process, hot filament electron-assisted chemical vapor deposition, and plasma generation of atomic hydrogen by glow discharge, microwave discharge, low pressure radio frequency discharge, high pressure DC discharge, high pressure microwave discharge jets, high pressure RF discharge, and high and low pressure flames. Other types of diamond deposition methods are also evaluated. 101 refs., 15 figs.

  8. The Mysteries of Diamonds: Bizarre History, Amazing Properties, Unique Applications

    International Nuclear Information System (INIS)

    Kagan, Harris

    2008-01-01

    Diamonds have been a prized material throughout history. They are scarce and beautiful, wars have been fought over them, and they remain today a symbol of wealth and power. Diamonds also have exceptional physical properties which can lead to unique applications in science. There are now techniques to artificially synthesize diamonds of extraordinarily high quality. In this talk, Professor Kagan will discuss the history of diamonds, their bizarre properties, and their manufacture and use for 21st century science.

  9. Encapsulation of electroless copper patterns into diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Pimenov, S.M.; Shafeev, G.A.; Lavrischev, S.V. [General Physics Institute, Moscow (Russian Federation)] [and others

    1995-12-31

    The results are reported on encapsulating copper lines into diamond films grown by a DC plasma CVD. The process includes the steps of (i) laser activation of diamond for electroless metal plating, (ii) electroless copper deposition selectively onto the activated surface regions, and (iii) diamond regrowth on the Cu-patterned diamond films. The composition and electrical properties of the encapsulated copper lines were examined, revealing high purity and low electrical resistivity of the encapsulated electroless copper.

  10. Alluvial Diamond Resource Potential and Production Capacity Assessment of Ghana

    Science.gov (United States)

    Chirico, Peter G.; Malpeli, Katherine C.; Anum, Solomon; Phillips, Emily C.

    2010-01-01

    In May of 2000, a meeting was convened in Kimberley, South Africa, and attended by representatives of the diamond industry and leaders of African governments to develop a certification process intended to assure that rough, exported diamonds were free of conflictual concerns. This meeting was supported later in 2000 by the United Nations in a resolution adopted by the General Assembly. By 2002, the Kimberley Process Certification Scheme (KPCS) was ratified and signed by both diamond-producing and diamond-importing countries. Over 70 countries were included as members at the end of 2007. To prevent trade in 'conflict' diamonds while protecting legitimate trade, the KPCS requires that each country set up an internal system of controls to prevent conflict diamonds from entering any imported or exported shipments of rough diamonds. Every diamond or diamond shipment must be accompanied by a Kimberley Process (KP) certificate and be contained in tamper-proof packaging. The objective of this study was to assess the alluvial diamond resource endowment and current production capacity of the alluvial diamond-mining sector in Ghana. A modified volume and grade methodology was used to estimate the remaining diamond reserves within the Birim and Bonsa diamond fields. The production capacity of the sector was estimated using a formulaic expression of the number of workers reported in the sector, their productivity, and the average grade of deposits mined. This study estimates that there are approximately 91,600,000 carats of alluvial diamonds remaining in both the Birim and Bonsa diamond fields: 89,000,000 carats in the Birim and 2,600,000 carats in the Bonsa. Production capacity is calculated to be 765,000 carats per year, based on the formula used and available data on the number of workers and worker productivity. Annual production is highly dependent on the international diamond market and prices, the numbers of seasonal workers actively mining in the sector, and

  11. The Mysteries of Diamonds: Bizarre History, Amazing Properties, Unique Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kagan, Harris (Ohio State University)

    2008-06-24

    Diamonds have been a prized material throughout history. They are scarce and beautiful, wars have been fought over them, and they remain today a symbol of wealth and power. Diamonds also have exceptional physical properties which can lead to unique applications in science. There are now techniques to artificially synthesize diamonds of extraordinarily high quality. In this talk, Professor Kagan will discuss the history of diamonds, their bizarre properties, and their manufacture and use for 21st century science.

  12. Aerogel Cerenkov counters at DESY

    International Nuclear Information System (INIS)

    Poelz, G.

    1984-11-01

    In high energy physics it is common to identify a charged particle and its kinematical parameters by the measurement of its momentum and its velocity. Cerenkov detectors have developed into a standard tool because they operate in the γ = (1-β 2 )sup(-1/2) range from about 1 to 100 which is not easily accessible by other devices. Pions, kaons and protons in present high energy experiments reach energies of several GeV. Threshold Cerenkov detectors for these particles need indices of refraction below 1.1 which are often produced with gases under high pressure. The design for chambers operating in this region was drasticly simplified when porous materials serving as Cerenkov radiators were invented. These chambers complement the time-of-flight counters, which cover the low energy region. Aerogel of silica is up to now the only porous substance with sufficient optical transparency. Its quality has been improved substantially in recent times so that large size detectors can be constructed. (orig.)

  13. Improvements in or relating to artefacts incorporating industrial diamonds

    International Nuclear Information System (INIS)

    Hartley, N.E.W.; Poole, M.J.

    1981-01-01

    A process for improving the wear characteristics of industrial diamonds is described which consists of implanting into the surface regions of the diamonds, ions of a material having an atomic weight greater than one and such as to affect the surface properties of the diamonds. Examples of the invention, in which N + and C + ions have been used, are cited. (U.K.)

  14. An assessment of radiotherapy dosimeters based on CVD grown diamond

    International Nuclear Information System (INIS)

    Ramkumar, S.; Buttar, C.M.; Conway, J.; Whitehead, A.J.; Sussman, R.S.; Hill, G.; Walker, S.

    2001-01-01

    Diamond is potentially a very suitable material for use as a dosimeter for radiotherapy. Its radiation hardness, the near tissue equivalence and chemical inertness are some of the characteristics of diamond, which make it well suited for its application as a dosimeter. Recent advances in the synthesis of diamond by chemical vapour deposition (CVD) technology have resulted in the improvement in the quality of material and increased its suitability for radiotherapy applications. We report in this paper, the response of prototype dosimeters based on two different types (CVD1 and CVD2) of CVD diamond to X-rays. The diamond devices were assessed for sensitivity, dependence of response on dose and dose rate, and compared with a Scanditronix silicon photon diode and a PTW natural diamond dosimeter. The diamond devices of CVD1 type showed an initial increase in response with dose, which saturates after ∼6 Gy. The diamond devices of CVD2 type had a response at low fields ( 1162.8 V/cm), the CVD2-type devices showed polarisation and dose-rate dependence. The sensitivity of the CVD diamond devices varied between 82 and 1300 nC/Gy depending upon the sample type and the applied voltage. The sensitivity of CVD diamond devices was significantly higher than that of natural diamond and silicon dosimeters. The results suggest that CVD diamond devices can be fabricated for successful use in radiotherapy applications

  15. Coesite inclusions in diamonds of Yakutia

    Science.gov (United States)

    Bardukhinov, L. D.; Spetsius, Z. V.; Monkhorov, R. V.

    2016-10-01

    The results of the study of diamonds with inclusions of high-pressure modification of SiO2 (coesite) by Raman spectroscopy are reported. It is established that the octahedral crystal from the Zapolyarnaya pipe is characterized by the highest residual pressure (2.7 ± 0.07 GPa). An intermediate value of this parameter (2.1 ± 0.07 GPa) was obtained for a crystal of transitional habit from the Maiskaya pipe. The minimal Raman shift was registered for coesite in diamond from the Komsomol'skaya-Magnitnaya pipe and provided a calculated residual pressure of 1.8 ± 0.03 GPa. The residual pressures for crystals from the placer deposits of the Kuoika and Bol'shaya Kuonamka rivers are 2.7 ± 0.07 and 3.1 ± 0.1 GPa, respectively. Octahedral crystals were formed in the mantle at a higher pressure than rhombododecahedral diamonds.

  16. CVD diamond detectors for ionizing radiation

    CERN Document Server

    Friedl, M; Bauer, C; Berfermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernegger, H; Pernicka, Manfred; Peitz, A; Pirollo, S; Polesello, P; Pretzl, Klaus P; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Tapper, R J; Tesarek, R J; Thomson, G B; Trawick, M L; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Ziock, H J; Zöller, M

    1999-01-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2*4 cm/sup 2/ have been grown and refined for better charge collection properties, which are measured with a beta source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5*10/sup 15/ cm/sup -2/ to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (16 refs).

  17. Recent results with CVD diamond trackers

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Procario, M.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Runolfsson, O.; Russ, J.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; White, C.; Ziock, H.; Zoeller, M

    1999-08-01

    We present recent results on the use of Chemical Vapor Deposition (CVD) diamond microstrip detectors for charged particle tracking. A series of detectors was fabricated using 1 x 1 cm{sup 2} diamonds. Good signal-to-noise ratios were observed using both slow and fast readout electronics. For slow readout electronics, 2 {mu}s shaping time, the most probable signal-to-noise ratio was 50 to 1. For fast readout electronics, 25 ns peaking time, the most probable signal-to-noise ratio was 7 to 1. Using the first 2 x 4 cm{sup 2} diamond from a production CVD reactor with slow readout electronics, the most probable signal-to-noise ratio was 23 to 1. The spatial resolution achieved for the detectors was consistent with the digital resolution expected from the detector pitch.

  18. Recent results with CVD diamond trackers

    CERN Document Server

    Adam, W; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernicka, Manfred; Peitz, A; Pirollo, S; Polesello, P; Pretzl, Klaus P; Procario, M; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Runólfsson, O; Russ, J; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R J; Trawick, M L; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; White, C; Ziock, H J; Zöller, M

    1999-01-01

    We present recent results on the use of chemical vapor deposition (CVD) diamond microstrip detectors for charged particle tracking. A series of detectors was fabricated using 1*1 cm/sup 2/ diamonds. Good signal-to-noise ratios were observed using both slow and fast readout electronics. For slow readout electronics, 2 mu s shaping time, the most probable signal-to-noise ratio was 50 to 1. For fast readout electronics, 25 ns peaking time, the most probable signal-to-noise ratio was 7 to 1. Using the first 2*4 cm/sup 2/ diamond from a production CVD reactor with slow readout electronics, the most probable signal-to-noise ratio was 23 to 1. The spatial resolution achieved for the detectors was consistent with the digital resolution expected from the detector pitch. (6 refs).

  19. CVD diamond detectors for ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Friedl, M. E-mail: markus.friedl@cern.ch; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R.J.; Tesarek, R.; Thomson, G.B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M

    1999-10-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2x4 cm{sup 2} have been grown and refined for better charge collection properties, which are measured with a {beta} source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5x10{sup 15} cm{sup -2} to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (author)

  20. CVD diamond detectors for ionizing radiation

    Science.gov (United States)

    Friedl, M.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fizzotti, F.; Foulon, F.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knöpfle, K. T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P. F.; Manfredotti, C.; Marshall, R. D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L. S.; Palmieri, V. G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J. L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.; RD42 Collaboration

    1999-10-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2×4 cm2 have been grown and refined for better charge collection properties, which are measured with a β source or in a testbeam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5×10 15 cm-2 to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics.

  1. Photoluminescent properties of single crystal diamond microneedles

    Science.gov (United States)

    Malykhin, Sergey A.; Ismagilov, Rinat R.; Tuyakova, Feruza T.; Obraztsova, Ekaterina A.; Fedotov, Pavel V.; Ermakova, Anna; Siyushev, Petr; Katamadze, Konstantin G.; Jelezko, Fedor; Rakovich, Yury P.; Obraztsov, Alexander N.

    2018-01-01

    Single crystal needle-like diamonds shaped as rectangular pyramids were produced by combination of chemical vapor deposition and selective oxidation with dimensions and geometrical characteristics depending on the deposition process parameters. Photoluminescence spectra and their dependencies on wavelength of excitation radiation reveal presence of nitrogen- and silicon-vacancy color centers in the diamond crystallites. Photoluminescence spectra, intensity mapping, and fluorescence lifetime imaging microscopy indicate that silicon-vacancy centers are concentrated at the crystallites apex while nitrogen-vacancy centers are distributed over the whole crystallite. Dependence of the photoluminescence on excitation radiation intensity demonstrates saturation and allows estimation of the color centers density. The combination of structural parameters, geometry and photoluminescent characteristics are prospective for advantageous applications of these diamond crystallites in quantum information processing and optical sensing.

  2. Diamond as a scaffold for bone growth.

    Science.gov (United States)

    Fox, Kate; Palamara, Joseph; Judge, Roy; Greentree, Andrew D

    2013-04-01

    Diamond is an attractive material for biomedical implants. In this work, we investigate its capacity as a bone scaffold. It is well established that the bioactivity of a material can be evaluated by examining its capacity to form apatite-like calcium phosphate phases on its surface when exposed to simulated body fluid. Accordingly, polycrystalline diamond (PCD) and ultrananocrystalline diamond (UNCD) deposited by microwave plasma chemical vapour deposition were exposed to simulated body fluid and assessed for apatite growth when compared to the bulk silicon. Scanning electron microscopy and X-ray photoelectron spectroscopy showed that both UNCD and PCD are capable of acting as a bone scaffold. The composition of deposited apatite suggests that UNCD and PCD are suitable for in vivo implantation with UNCD possible favoured in applications where rapid osseointegration is essential.

  3. Conductivity and superconductivity in heavily vacant diamond

    Directory of Open Access Journals (Sweden)

    S A Jafari

    2009-08-01

    Full Text Available   Motivated by the idea of impurity band superconductivity in heavily Boron doped diamond, we investigate the doping of various elements into diamond to address the question, which impurity band can offer a better DOS at the Fermi level. Surprisingly, we find that the vacancy does the best job in producing the largest DOS at the Fermi surface. To investigate the effect of disorder in Anderson localization of the resulting impurity band, we use a simple tight-binding model. Our preliminary study based on the kernel polynomial method shows that the impurity band is already localized at the concentration of 10-3. Around the vacancy concentration of 0.006 the whole spectrum of diamond becomes localized and quantum percolation takes place. Therefore to achieve conducting bands at concentrations on the scale of 5-10 percent, one needs to introduce correlations such as hopping among the vacancies .

  4. Note: Evaluation of microfracture strength of diamond materials using nano-polycrystalline diamond spherical indenter

    Science.gov (United States)

    Sumiya, H.; Hamaki, K.; Harano, K.

    2018-05-01

    Ultra-hard and high-strength spherical indenters with high precision and sphericity were successfully prepared from nanopolycrystalline diamond (NPD) synthesized by direct conversion sintering from graphite under high pressure and high temperature. It was shown that highly accurate and stable microfracture strength tests can be performed on various super-hard diamond materials by using the NPD spherical indenters. It was also verified that this technique enables quantitative evaluation of the strength characteristics of single crystal diamonds and NPDs which have been quite difficult to evaluate.

  5. Tracing the depositional history of Kalimantan diamonds by zircon provenance and diamond morphology studies

    Science.gov (United States)

    Kueter, Nico; Soesilo, Joko; Fedortchouk, Yana; Nestola, Fabrizio; Belluco, Lorenzo; Troch, Juliana; Wälle, Markus; Guillong, Marcel; Von Quadt, Albrecht; Driesner, Thomas

    2016-11-01

    Diamonds in alluvial deposits in Southeast Asia are not accompanied by indicator minerals suggesting primary kimberlite or lamproite sources. The Meratus Mountains in Southeast Borneo (Province Kalimantan Selatan, Indonesia) provide the largest known deposit of these so-called "headless" diamond deposits. Proposals for the origin of Kalimantan diamonds include the adjacent Meratus ophiolite complex, ultra-high pressure (UHP) metamorphic terranes, obducted subcontinental lithospheric mantle and undiscovered kimberlite-type sources. Here we report results from detailed sediment provenance analysis of diamond-bearing Quaternary river channel material and from representative outcrops of the oldest known formations within the Alino Group, including the diamond-bearing Campanian-Maastrichtian Manunggul Formation. Optical examination of surfaces of diamonds collected from artisanal miners in the Meratus area (247 stones) and in West Borneo (Sanggau Area, Province Kalimantan Barat; 85 stones) points toward a classical kimberlite-type source for the majority of these diamonds. Some of the diamonds host mineral inclusions suitable for deep single-crystal X-ray diffraction investigation. We determined the depth of formation of two olivines, one coesite and one peridotitic garnet inclusion. Pressure of formation estimates for the peridotitic garnet at independently derived temperatures of 930-1250 °C are between 4.8 and 6.0 GPa. Sediment provenance analysis includes petrography coupled to analyses of detrital garnet and glaucophane. The compositions of these key minerals do not indicate kimberlite-derived material. By analyzing almost 1400 zircons for trace element concentrations with laser ablation ICP-MS (LA-ICP-MS) we tested the mineral's potential as an alternative kimberlite indicator. The screening ultimately resulted in a small subset of ten zircons with a kimberlitic affinity. Subsequent U-Pb dating resulting in Cretaceous ages plus a detailed chemical reflection make

  6. Counter-diabatic driving for Dirac dynamics

    Science.gov (United States)

    Fan, Qi-Zhen; Cheng, Xiao-Hang; Chen, Xi

    2018-03-01

    In this paper, we investigate the fast quantum control of Dirac equation dynamics by counter-diabatic driving, sharing the concept of shortcut to adiabaticity. We systematically calculate the counter-diabatic terms in different Dirac systems, like graphene and trapped ions. Specially, the fast and robust population inversion processes are achieved in Dirac system, taking into account the quantum simulation with trapped ions. In addition, the population transfer between two bands can be suppressed by counter-diabatic driving in graphene system, which might have potential applications in opt-electric devices.

  7. 21 CFR 866.2170 - Automated colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated colony counter. (a) Identification. An automated colony counter is a mechanical device intended for medical...

  8. Electron field emission for ultrananocrystalline diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, A. R.; Auciello, O.; Ding, M. Q.; Gruen, D. M.; Huang, Y.; Zhirnov, V. V.; Givargizov, E. I.; Breskin, A.; Chechen, R.; Shefer, E. (and others)

    2001-03-01

    Ultrananocrystalline diamond (UNCD) films 0.1--2.4 {mu}m thick were conformally deposited on sharp single Si microtip emitters, using microwave CH{sub 4}--Ar plasma-enhanced chemical vapor deposition in combination with a dielectrophoretic seeding process. Field-emission studies exhibited stable, extremely high (60--100 {mu}A/tip) emission current, with little variation in threshold fields as a function of film thickness or Si tip radius. The electron emission properties of high aspect ratio Si microtips, coated with diamond using the hot filament chemical vapor deposition (HFCVD) process were found to be very different from those of the UNCD-coated tips. For the HFCVD process, there is a strong dependence of the emission threshold on both the diamond coating thickness and Si tip radius. Quantum photoyield measurements of the UNCD films revealed that these films have an enhanced density of states within the bulk diamond band gap that is correlated with a reduction in the threshold field for electron emission. In addition, scanning tunneling microscopy studies indicate that the emission sites from UNCD films are related to minima or inflection points in the surface topography, and not to surface asperities. These data, in conjunction with tight binding pseudopotential calculations, indicate that grain boundaries play a critical role in the electron emission properties of UNCD films, such that these boundaries: (a) provide a conducting path from the substrate to the diamond--vacuum interface, (b) produce a geometric enhancement in the local electric field via internal structures, rather than surface topography, and (c) produce an enhancement in the local density of states within the bulk diamond band gap.

  9. Clinical dosimeter based on diamond detector

    International Nuclear Information System (INIS)

    Chervjakov, A.M.; Ljalina, L.I.; Ljutina, G.J.; Khrunov, V.S.; Martynov, S.S.; Popov, S.A.

    2002-01-01

    Full text: Diamond detectors have found application in the relative dosimetry and their parameters have been described elsewhere. Today, the exclusive producer of the diamond detector is the Institute of Physical and Technical Problems, Russia, and exclusive dealer is the PTW-Freiburg. The main features of the diamond detector are good long time stability, suitable range of the energy dependence for photon and electron beams in clinical use, independence of the measured date from temperature and pressure. The high sensitivity per volume unit of the diamond detector (1500 times higher than ionization chamber) allowed using detectors with very small volume (1-5 mm 3 ) and rather simple electronics for ionization current registration. The new dosimeter consists of the diamond detector itself, 40 m registration cable, pre-amplifier, micro-processor block for data handling and absorbed dose calculation using the calibration factor of diamond detector in terms of absorbed dose to water. Dosimeter has the possibility to work with PC using standard RS-232 interface. The main features of the dosimeter are as follows: the range of dose rate measurements for photon, electron and proton beams is within 0.01-1.0 Gy/s; the energy ranges for photons are 0.08-25 MeV, and 4-25 MeV for electrons, with energy dependence no more than ±2%; the main uncertainty of the dose measurements is within ±2%; the pre-irradiation dose for diamond detector is no more than 10 Gy; the sensitive volume of the used diamond detectors is within 1-5 mm 3 ; the weight of the dosimeter no more than 2 kg. The new dosimeter was evaluated at the Central Research Institute of Roentgenology and Radiology, St. Petersburg, Russia to verify its performance. The dosimeter was used as a reference instrument for dose measurements at Cobalt-60 unit, SL75-5 and SL-20 linear accelerators and the test results have shown that the device have met the specifications. It is planned to produce dosimeter as serial device by

  10. Progress of Diamond-like Carbon Films

    Directory of Open Access Journals (Sweden)

    CHEN Qing-yun

    2017-03-01

    Full Text Available Diamond-like carbon(DLC films had many unique and outstanding properties such as high thermal conductivity, high hardness, excellent chemical inertness, low friction coefficients and wear coefficients. The properties and combinations were very promising for heat sink, micro-electromechanical devices, radiation hardening, biomedical devices, automotive industry and other technical applications, more research and a lot of attention were attracted in recent years. The research progress of diamond-like films and the nucleation mechanism of film were summarized, and application prospect of DLC films were demonstrated. The aim of this paper is to provide insights on the research trend of DLC films and the industry applications.

  11. Diamond drilling for nuclear waste QC

    International Nuclear Information System (INIS)

    Jennings, Martin.

    1990-01-01

    Specialised diamond core drilling equipment could soon have a role to play in the safe disposal of intermediate level radioactive waste (ILW). Equipment to core and extract samples for quality checking from cement-filled steel waste drums by techniques compatible with eventual remote-handling operations in a 'hot-cell' is being developed. All coring tests carried out to date have been on simulant waste: 200 litre drums containing mixtures of Ordinary Portland Cement, Ground Granulated Blast Furnace Slag and Pulverised Fuel Ash. No radioactive materials have yet been used for the coring trials. The coring equipment and the diamond coring bits are described. (author)

  12. D.C. Arcjet Diamond Deposition

    Science.gov (United States)

    Russell, Derrek Andrew

    1995-01-01

    Polycrystalline diamond films synthesized by a D.C. (direct current) arcjet device was reported for the first time in 1988. This device is capable of higher diamond growth rates than any other form of diamond CVD (chemical vapor deposition) process due to its inherent versatility with regard to the enthalpy and fluid properties of the diamond-depositing vapor. Unfortunately, the versatility of this type of device is contrasted by many difficulties such as arc stability and large heat fluxes which make applying it toward diamond deposition a difficult problem. The purpose of this work was to convert the dc arcjet, which is primarily a metallurgical device, into a commercially viable diamond CVD process. The project was divided into two parts: process development and diagnostics. The process development effort concentrated on the certain engineering challenges. Among these was a novel arcjet design that allowed the carbon-source gas to be injected downstream of the tungsten cathode while still facilitating mixture with the main gas feed. Another engineering accomplishment was the incorporation of a water -cooled substrate cooler/spinner that maintained the substrate at the proper temperature, provided the substrate with a large thermal time constant to reduce thermal shock of the diamond film, and enabled the system to achieve a four -inch diameter growth area. The process diagnostics effort concentrated on measurements aimed at developing a fundamental understanding of the properties of the plasma jet such as temperature, plasma density, Mach number, pressure at the substrate, etc. The plasma temperature was determined to be 5195 K by measuring the rotational temperature of C _2 via optical emission spectroscopy. The Mach number of the plasma jet was determined to be ~6.0 as determined by the ratio of the stagnation pressures before and after the shock wave in the plasma jet. The C_2 concentration in the plasma jet was determined to be {~10 }^{12} cm^ {-3} by

  13. Thermal diffusivity of diamond films using a laser pulse technique

    International Nuclear Information System (INIS)

    Albin, S.; Winfree, W.P.; Crews, B.S.

    1990-01-01

    Polycrystalline diamond films were deposited using a microwave plasma-enhanced chemical vapor deposition process. A laser pulse technique was developed to measure the thermal diffusivity of diamond films deposited on a silicon substrate. The effective thermal diffusivity of a diamond film on silicon was measured by observing the phase and amplitude of the cyclic thermal waves generated by laser pulses. An analytical model is presented to calculate the effective inplane (face-parallel) diffusivity of a two-layer system. The model is used to reduce the effective thermal diffusivity of the diamond/silicon sample to a value for the thermal diffusivity and conductivity of the diamond film

  14. High-pressure-high-temperature treatment of natural diamonds

    CERN Document Server

    Royen, J V

    2002-01-01

    The results are reported of high-pressure-high-temperature (HPHT) treatment experiments on natural diamonds of different origins and with different impurity contents. The diamonds are annealed in a temperature range up to 2000 sup o C at stabilizing pressures up to 7 GPa. The evolution is studied of different defects in the diamond crystal lattice. The influence of substitutional nitrogen atoms, plastic deformation and the combination of these is discussed. Diamonds are characterized at room and liquid nitrogen temperature using UV-visible spectrophotometry, Fourier transform infrared spectrophotometry and photoluminescence spectrometry. The economic implications of diamond HPHT treatments are discussed.

  15. Application of CVD diamond film for radiation detection

    International Nuclear Information System (INIS)

    Zhou Haiyang; Zhu Xiaodong; Zhan Rujuan

    2005-01-01

    With the development of diamond synthesis at low pressure, the CVD diamond properties including electronic characteristics have improved continuously. Now the fabrication of electronic devices based on the CVD diamond has been one of hot research subjects in this field. Due to many unique advantages, such as high signal-noise ratio, fast time response, and normal output in extremely harsh surrounding, the CVD diamond radiation detector has attracted more and more interest. In this paper, we have reviewed the development and status of the CVD diamond radiation detector. The prospect of this detector is described. (authors)

  16. The counter ion: expanding excipient functionality

    Directory of Open Access Journals (Sweden)

    Shireesh Apte

    2011-06-01

    Full Text Available Excipients have increasingly become 'enablers' of drug delivery and efficacy rather than passive bystanders. Advances in pharmaceutical technology have enabled the ability to deliver specific counter ions (in the form of the counter ion containing excipient and the API simultaneously to preselected targets in the body. This, coupled with a near universal mechanism of columbic interactions that determine the [API- counter ion] efficacy, can be harnessed to exploit this hitherto unavailable or unrecognized enabling mechanism. New excipients may be assembled by a near inexhaustible supply of different permutations of counter ions and their judicious use in specific situations could potentially drive a renaissance in excipient innovation (and drug delivery and efficacy despite regulatory stagnation.

  17. Geometric covers, graph orientations, counter games

    DEFF Research Database (Denmark)

    Berglin, Edvin

    -directed graph is dynamic (can be altered by some outside actor), some orientations may need to be reversed in order to maintain the low out-degree. We present a new algorithm that is simpler than earlier work, yet matches or outperforms the efficiency of these results with very few exceptions. Counter games...... example is Line Cover, also known as Point-Line Cover, where a set of points in a geometric space are to be covered by placing a restricted number of lines. We present new FPT algorithms for the sub-family Curve Cover (which includes Line Cover), as well as for Hyperplane Cover restricted to R 3 (i...... are a type of abstract game played over a set of counters holding values, and these values may be moved between counters according to some set of rules. Typically they are played between two players: the adversary who tries to concentrate the greatest value possible in a single counter, and the benevolent...

  18. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A critical evaluaton is presented of the actual state of investigations and explanations of the resolution and pulse height changes resulted in proportional counters from radiation intensity variations. (author)

  19. Counter-Leadership Targeting and Conflict Termination

    National Research Council Canada - National Science Library

    Taylor, Bradly

    1999-01-01

    .... Can the leader be found? And, is it legal and ethical to attack the leader? Analysis rarely has been conducted to determine whether the targeted organization is vulnerable to Counter Leadership Targeting (CLT...

  20. Countering North Korean Special Purpose Forces

    National Research Council Canada - National Science Library

    Krause, Troy

    1999-01-01

    As United States and Republic of Korea forces stand to defend against a DPRK attack, one of the most formidable tasks is how to counter a second front in the Joint Rear Security Area of the Republic of Korea...

  1. Tests of BF3 counters with getter

    International Nuclear Information System (INIS)

    Comte, R.; Dauphin, G.

    1968-01-01

    BF 3 counters with addition of a getter have been developed to improve operation characteristics of these detectors in presence of strong gamma flows. The getter is made of an active coal deposit on the cathode. As noticed by other studies, the degradation of these counters is related to the exposure to strong neutron flows and to gamma radiations. The authors report tests performed on these counters with a brief presentation of the counters, and a presentation of the test installation. A threshold curve and an amplitude spectrum are obtained, and counting is performed for a fixed threshold before and after the exposure of detectors to variable doses of γ radiation. The results after a first 2 hour long irradiation, a 230 hour long second irradiation, and a third irradiation under high voltage (2100 V) are discussed. Thermal tests are then performed and commented

  2. Real-time {sup 90}Sr Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Naomi; Kawai, Hideyuki; Kodama, Satoshi; Kobayashi, Atsushi; Tabata, Makoto; Ito, Hiroshi [Graduate School of Science, Chiba University, Chiba, (Japan); Han, Soorim [Graduate School of Science, Chiba University, Chiba, (Japan); National Institute of Radiological Science, Chiba, (Japan)

    2015-07-01

    Radioisotopes have been emitted around Japan due to a nuclear accident at the Fukushima Daiichi nuclear power station in March 2011. A problem is the contaminated water including the atomic nucleus which relatively has a long half- life time and soluble such as {sup 90}Sr, {sup 137}Cs. Internal exposures by {sup 90}Sr are more dangerous than {sup 137}Cs's because Sr has effective half-life time of 18 years and property of accumulation in a born. We have developed real-time {sup 90}Sr counter which is sensitive beta-ray of maximum kinematic energy of 2.28 MeV from {sup 90}Sr and insensitive of beta-ray of maximum kinematic energy of 1.17 MeV and gamma-ray from {sup 90}Sr by Cherenkov detection. This counter composes of Cerenkov counter, trigger scintillation counter and veto counter. Silica aerogel for Cherenkov counter can obtain refractive index between 1.017 and 1.049 easily. And wavelength shifting fiber (WLSF) is used as a light guide for extending effective area and producing lower cost. A mechanism of the identification of {sup 90}Sr is explained in following. In case of {sup 90}Sr, when the trigger counter reacts on the beta-ray from {sup 90}Sr, aerogel emits the Cherenkov light and WLSF reacts and read the Cherenkov light. On the other hand, in case of {sup 137}Cs, the trigger counter reacts on the beta-ray, aerogel stops the beta- ray and Cherenkov light is not emitted. Therefore, aerogel has a function as a radiator and shielding material. the gamma-ray is not reacted on the lower density detector. Cosmic rays would be also reacted by the veto counter. A prototype counter whose the effective area is 30 cm x 10 cm was obtained (2.0±1.2){sup 3} of mis-identification as {sup 137}Cs/{sup 90}Sr. Detection limit in the surface contamination inspection depends on measurement time and effective area mainly. The sensitivity of wide range, 10{sup -2} - 10{sup 4} Bq/cm{sup 2}, is obtained by adjustment of detection level in circuit of this counter. A lower

  3. PREFACE: Science's gem: diamond science 2009 Science's gem: diamond science 2009

    Science.gov (United States)

    Mainwood, Alison; Newton, Mark E.; Stoneham, Marshall

    2009-09-01

    Natural diamond has been valued for its appearance and mechanical properties for at least two thousand years. As a gem stone diamond is unsurpassed. However, scientific work, especially in the last 20 years, has demonstrated that diamond has numerous surprising properties and many unique ones. Some of the extreme properties have been known for many years, but the true scale of diamond's other highly desirable features is still only coming to light as control in the synthesis of diamond, and hence material perfection, improves. The ultimate prize for man-made diamond is surely not in the synthesis of gem stones, but in delivering technological solutions enabled by diamond to the challenges facing our society today. If the special properties are to be exploited to their full potential, at least four crucial factors must be considered. First, there must be sufficient scientific understanding of diamond to make applications effective, efficient and economical. Secondly, the means of fabrication and control of properties have to be achieved so that diamond's role can be optimised. Thirdly, it is not enough that its properties are superior to existing materials: they must be so much better that it is worth initiating new technologies to exploit them. Finally, any substantial applications will have to address the society's major needs worldwide. The clear technology drivers for the 21st century come from the biomedical technologies, the demand for energy subject to global constraints, and the information technologies, where perhaps diamond will provide the major enabling technology [1]. The papers in this volume concern the solid state physics of diamond, and primarily concern the first two factors: understanding, and control of properties. They address many of the outstanding basic problems, such as the identification of existing defects, which affect the material's properties, both desirable and less so. Regarding future substantial applications, one paper discusses

  4. Homo-epitaxial diamond film growth on ion implanted diamond substrates

    Energy Technology Data Exchange (ETDEWEB)

    Weiser, P.S.; Prawer, S.; Nugent, K.W.; Bettiol, A.A.; Kostidis, L.I.; Jamieson, D.N. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    The nucleation of CVD diamond is a complicated process, governed by many interrelated parameters. In the present work we attempt to elucidate the effect of strain on the growth of a homo-epitaxial CVD diamond. We have employed laterally confined high dose (MeV) Helium ion implantation to produce surface swelling of the substrate. The strain is enhanced by the lateral confinement of the implanted region to squares of 100 x 100 {mu}m{sup 2}. After ion implantation, micro-Raman spectroscopy was employed to map the surface strain. The substrates were then inserted into a CVD reactor and a CVD diamond film was grown upon them. Since the strained regions were laterally confined, it was then possible to monitor the effect of strain on diamond nucleation. The substrates were also analysed using Rutherford Backscattering Spectroscopy (RBS), Proton induced X-ray Emission (PIXE) and Ion Beam induced Luminescence (IBIL). 7 refs., 5 figs.

  5. Homo-epitaxial diamond film growth on ion implanted diamond substrates

    Energy Technology Data Exchange (ETDEWEB)

    Weiser, P S; Prawer, S; Nugent, K W; Bettiol, A A; Kostidis, L I; Jamieson, D N [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    The nucleation of CVD diamond is a complicated process, governed by many interrelated parameters. In the present work we attempt to elucidate the effect of strain on the growth of a homo-epitaxial CVD diamond. We have employed laterally confined high dose (MeV) Helium ion implantation to produce surface swelling of the substrate. The strain is enhanced by the lateral confinement of the implanted region to squares of 100 x 100 {mu}m{sup 2}. After ion implantation, micro-Raman spectroscopy was employed to map the surface strain. The substrates were then inserted into a CVD reactor and a CVD diamond film was grown upon them. Since the strained regions were laterally confined, it was then possible to monitor the effect of strain on diamond nucleation. The substrates were also analysed using Rutherford Backscattering Spectroscopy (RBS), Proton induced X-ray Emission (PIXE) and Ion Beam induced Luminescence (IBIL). 7 refs., 5 figs.

  6. Study on the Effect of Diamond Grain Size on Wear of Polycrystalline Diamond Compact Cutter

    Science.gov (United States)

    Abdul-Rani, A. M.; Che Sidid, Adib Akmal Bin; Adzis, Azri Hamim Ab

    2018-03-01

    Drilling operation is one of the most crucial step in oil and gas industry as it proves the availability of oil and gas under the ground. Polycrystalline Diamond Compact (PDC) bit is a type of bit which is gaining popularity due to its high Rate of Penetration (ROP). However, PDC bit can easily wear off especially when drilling hard rock. The purpose of this study is to identify the relationship between the grain sizes of the diamond and wear rate of the PDC cutter using simulation-based study with FEA software (ABAQUS). The wear rates of a PDC cutter with a different diamond grain sizes were calculated from simulated cuttings of cutters against granite. The result of this study shows that the smaller the diamond grain size, the higher the wear resistivity of PDC cutter.

  7. Homo-epitaxial diamond film growth on ion implanted diamond substrates

    International Nuclear Information System (INIS)

    Weiser, P.S.; Prawer, S.; Nugent, K.W.; Bettiol, A.A.; Kostidis, L.I.; Jamieson, D.N.

    1996-01-01

    The nucleation of CVD diamond is a complicated process, governed by many interrelated parameters. In the present work we attempt to elucidate the effect of strain on the growth of a homo-epitaxial CVD diamond. We have employed laterally confined high dose (MeV) Helium ion implantation to produce surface swelling of the substrate. The strain is enhanced by the lateral confinement of the implanted region to squares of 100 x 100 μm 2 . After ion implantation, micro-Raman spectroscopy was employed to map the surface strain. The substrates were then inserted into a CVD reactor and a CVD diamond film was grown upon them. Since the strained regions were laterally confined, it was then possible to monitor the effect of strain on diamond nucleation. The substrates were also analysed using Rutherford Backscattering Spectroscopy (RBS), Proton induced X-ray Emission (PIXE) and Ion Beam induced Luminescence (IBIL). 7 refs., 5 figs

  8. Counter - Drug: Mandate for the Army.

    Science.gov (United States)

    1991-03-01

    this comprehensive review will provide a basis for responding to new missions assigned...observations for determining the short-, mid-, and long-term direction of Army support to the national counter-drug effort. Also, this comprehensive review will provide...and long-term direction of Army support to the national counter-drug effort. Also, this comprehensive review will provide a basis for responding

  9. Lifetime characteristics of Gaiger-Muller counters

    Directory of Open Access Journals (Sweden)

    Kartalović Nenad M.

    2016-01-01

    Full Text Available This paper discusses the process of functional aging of Geiger-Muller counters. Two types of Geiger-Muller counter chambers were characterized in an experiment using a combined constant voltage. Chamber A had a coaxial geometry and chamber B had a plan-parallel geometry. The experimental results indicate that the aging process was faster in the case of chambers with a coaxial geometry. The results are explained based on the process of electrical discharges in gasses.

  10. Quality control and the multicrystal counter

    International Nuclear Information System (INIS)

    Hart, G.C.; Davis, K.M.

    1983-01-01

    The reliability of multicrystal counters for use in counting large numbers of radioimmunoassay samples is studied. In particular, the dependencies of the outputs from the array of detectors, and hence their degree of matching, on the count rate and volume of the samples being counted are investigated. Quality control procedures are described to assist in the assurance of consistent performance of the counter in the clinical situation. (U.K.)

  11. Pulse formation of gas-filled counter

    International Nuclear Information System (INIS)

    Iwatani, Kazuo; Teshima, Kazunori; Shizuma, Kiyoshi; Hasai, Hiromi

    1991-01-01

    The pulse formation of gas-filled counter has been calculated by simple models for the proportional and self-quenching streamer (SQS) modes. Calculated pulse shapes of counter output have accurately reproduced the observed ones for both modes. As a result, it is shown that the special density distribution of ion pairs in a streamer can be estimated with the rising part of observed pulse shape, using the model. (author)

  12. Development of a Mobile Ice Nucleus Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Gregory [Droplet Measurement Technologies, Boulder, CO (United States); Kulkarni, Gourihar [Droplet Measurement Technologies, Boulder, CO (United States)

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70°C, and a single stage system can operate the warm wall at -45C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  13. X-ray topographic study of diamonds: implications for the genetic nature of inclusions in diamond

    Science.gov (United States)

    Agrosì, Giovanna; Nestola, Fabrizio; Tempesta, Gioacchino; Bruno, Marco; Scandale, Eugenio; Harris, Jeff W.

    2014-05-01

    In recent years, several studies have focused on the growth conditions of the diamonds through the analysis of the mineral inclusions trapped in them (Howell, 2012 and references therein). Nevertheless, to obtain rigorous information about chemical and physical conditions of diamond formation, it is crucial to determine if the crystallization of the inclusions occurred before (protogenetic nature), during (syngenetic nature) or after (epigenetic nature) the growth of diamond (Wiggers de Vries et al., 2011). X-ray topography (XRDT) can be a helpful tool to verify the genetic nature of inclusions in diamond. This technique characterizes the extended defects and reconstructs the growth history of the samples (Agrosì et al., 2013 and references therein) and, consequently contributes to elucidation of the relationship between the inclusions and the host-diamond. With this aim a diamond from the Udachnaya kimberlite, Siberia, was investigated. The diamond crystal was the one previously studied by Nestola et al. (2011) who performed in-situ crystal structure refinement of the inclusions to obtain data about the formation pressure. The inclusions were iso-oriented olivines that did not show evident cracks and subsequently could not be considered epigenetic. Optical observations revealed an anomalous birefringence in the adjacent diamond and the inclusions had typical "diamond-imposed cubo-octahedral" shape for the largest olivine. The diffraction contrast study shows that the diamond exhibits significant deformation fields related to plastic post growth deformation. The crystallographic direction of strains was established applying the extinction criterion. Section topographs were taken to minimize the overlapping of the strain field associate with the different defects and revealed that no dislocations nucleated from the olivine inclusions. Generally, when a solid inclusion has been incorporated in the growing crystal, the associated volume distortion can be minimized by

  14. One step deposition of highly adhesive diamond films on cemented carbide substrates via diamond/β-SiC composite interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tao; Zhuang, Hao; Jiang, Xin, E-mail: xin.jiang@uni-siegen.de

    2015-12-30

    Graphical abstract: - Highlights: • Novel diamond/beta-silicon carbide composite gradient interlayers were synthesized. • The interlayer features a cross-sectional gradient with increasing diamond content. • Diamond top layers and the interlayers were deposited in one single process. • The adhesion of the diamond film is drastically improved by employing the interlayer. • The stress was suppressed by manipulating the distribution of diamond and silicon carbide. - Abstract: Deposition of adherent diamond films on cobalt-cemented tungsten carbide substrates has been realized by application of diamond/beta-silicon carbide composite interlayers. Diamond top layers and the interlayers were deposited in one single process by hot filament chemical vapor deposition technique. Two different kinds of interlayers have been employed, namely, gradient interlayer and interlayer with constant composition. The distribution of diamond and beta-silicon carbide phases was precisely controlled by manipulating the gas phase composition. X-ray diffraction and Raman spectroscopy were employed to determine the existence of diamond, beta-silicon carbide and cobalt silicides (Co{sub 2}Si, CoSi) phases, as well as the quality of diamond crystal and the residual stress in the films. Rockwell-C indentation tests were carried out to evaluate the film adhesion. It is revealed that the adhesion of the diamond film is drastically improved by employing the interlayer. This is mainly influenced by the residual stress in the diamond top layer, which is induced by the different thermal expansion coefficient of the film and the substrate. It is even possible to further suppress the stress by manipulating the distribution of diamond and beta-silicon carbide in the interlayer. The most adhesive diamond film on cemented carbide is thus obtained by employing a gradient composite interlayer.

  15. Diamond MEMS: wafer scale processing, devices, and technology insertion

    Science.gov (United States)

    Carlisle, J. A.

    2009-05-01

    Diamond has long held the promise of revolutionary new devices: impervious chemical barriers, smooth and reliable microscopic machines, and tough mechanical tools. Yet it's been an outsider. Laboratories have been effectively growing diamond crystals for at least 25 years, but the jump to market viability has always been blocked by the expense of diamond production and inability to integrate with other materials. Advances in chemical vapor deposition (CVD) processes have given rise to a hierarchy of carbon films ranging from diamond-like carbon (DLC) to vapor-deposited diamond coatings, however. All have pros and cons based on structure and cost, but they all share some of diamond's heralded attributes. The best performer, in theory, is the purest form of diamond film possible, one absent of graphitic phases. Such a material would capture the extreme hardness, high Young's modulus and chemical inertness of natural diamond. Advanced Diamond Technologies Inc., Romeoville, Ill., is the first company to develop a distinct chemical process to create a marketable phase-pure diamond film. The material, called UNCD® (for ultrananocrystalline diamond), features grain sizes from 3 to 300 nm in size, and layers just 1 to 2 microns thick. With significant advantages over other thin films, UNCD is designed to be inexpensive enough for use in atomic force microscopy (AFM) probes, microelectromechanical machines (MEMS), cell phone circuitry, radio frequency devices, and even biosensors.

  16. Mechanical pretreatment for improved adhesion of diamond coatings

    International Nuclear Information System (INIS)

    Toenshoff, H.K.; Mohlfeld, A.; Gey, C.; Winkler, J.

    1999-01-01

    Diamond coatings are mainly used in cutting processes due to their tribological characteristics. They show a high hardness, low friction coefficient, high wear resistance and good chemical inertness. In relation to polycrystalline diamond (PCD)-tipped cutting inserts, especially the advantageous chemical stability of diamond coatings is superior as no binder phases between diamond grains are used. However, the deposition of adherent high-quality diamond coatings has been found difficult. Thus, substrate pretreatment is utilised to improve film adhesion. This investigation is based on water peening of the substrate material before coating. The investigation revealed best results for diamond film adhesion on pretreated substrates compared to conventional diamond coatings on cemented carbide tools applied with the CVD hot-filament process. In final cutting tests with increased film adhesion trough water peened cutting tools an improved wear behavior was detected. (orig.)

  17. Polarized Raman spectroscopy of chemically vapour deposited diamond films

    International Nuclear Information System (INIS)

    Prawer, S.; Nugent, K.W.; Weiser, P.S.

    1994-01-01

    Polarized micro-Raman spectra of chemically vapour deposited diamond films are presented. It is shown that important parameters often extracted from the Raman spectra such as the ratio of the diamond to non-diamond component of the films and the estimation of the level of residual stress depend on the orientation of the diamond crystallites with respect to the polarization of the incident laser beam. The dependence originates from the fact that the Raman scattering from the non-diamond components in the films is almost completely depolarized whilst the scattering from the diamond components is strongly polarized. The results demonstrate the importance of taking polarization into account when attempting to use Raman spectroscopy in even a semi-quantitative fashion for the assessment of the purity, perfection and stress in CVD diamond films. 8 refs., 1 tab. 2 figs

  18. ROLE OF DIAMOND SECONDARY EMITTERS IN HIGH BRIGHTNESS ELECTRON SOURCES

    International Nuclear Information System (INIS)

    2005-01-01

    In this paper we explore the possibility of using diamond secondary emitter in a high average current electron injector to amplify the current from the photocathode and to isolate the cathode and the injector from each other to increase the life time of the cathode and preserve the performance of the injector. Secondary electron yield of 225 and current density of 0.8 a/cm 2 have been measured in the transmission mode from type 2 a natural diamond. Although the diamond will be heated during normal operation in the injector, calculations indicate that by cryogenically cooling the diamond, the temperature gradient along the diamond can be maintained within the acceptable range. The electron energy and temporal distributions are expected to be narrow from this device resulting in high brightness beams. Plans are underway to measure the SEY in emission mode, fabricate photocathode-diamond capsule and test diamond and capsule in superconducting RF injector

  19. Diamond particle detectors systems in high energy physics

    CERN Document Server

    Gan, Kock Kiam

    2015-01-01

    The measurement of luminosity at the Large Hadron Collider (LHC) using diamond detect or s has matured from devices based on a rather large pads to highly granular pixelated device s . The ATLAS experiment has recently installed a diamond pixel detector, the Diamond Beam Monitor (DBM), to measure the luminosity in the upgraded LHC with higher instantaneous luminosity. Polycrystalline diamonds were used to fabricate the diamond pixel modules. The design , production, and test beam result s are described. CMS also has a similar plan to construct a diamond based luminosity monitor, the Pixel Luminos ity Telescope s (PLT) . In a pilot run using single crystal diamond, the pulse height was found to depend on the luminosity . Consequently the collaboration decided to use silicon instead due to time constrain ts .

  20. Diamond Beamline I16 (Materials and Magnetism)

    International Nuclear Information System (INIS)

    Collins, S. P.; Bombardi, A.; Marshall, A. R.; Williams, J. H.; Barlow, G.; Day, A. G.; Pearson, M. R.; Woolliscroft, R. J.; Walton, R. D.; Beutier, G.; Nisbet, G.

    2010-01-01

    We describe the key features and performance specifications of a facility for high-resolution single-crystal x-ray diffraction at Diamond Light Source. The scientific emphasis of the beamline is materials- and x-ray-physics, including resonant and magnetic scattering. We highlight some of the more novel aspects of the beamline design.

  1. Diamond Light Source: status and perspectives.

    Science.gov (United States)

    Materlik, Gerhard; Rayment, Trevor; Stuart, David I

    2015-03-06

    Diamond Light Source, a third-generation synchrotron radiation (SR) facility in the UK, celebrated its 10th anniversary in 2012. A private limited company was set up in April 2002 to plan, construct and operate the new user-oriented SR facility, called in brief Diamond. It succeeded the Synchrotron Radiation Source in Daresbury, a second-generation synchrotron that opened in 1980 as the world's first dedicated X-ray-providing facility, closing finally in 2008, by which time Diamond's accelerators and first beamlines were operating and user experiments were under way. This theme issue of Philosophical Transactions of the Royal Society A gives some examples of the rich diversity of research done in the initial five years, with some glimpses of activity up to 2014. Speakers at the 10 year anniversary symposium were drawn from a small number of major thematic areas and each theme was elaborated by a few speakers whose contributions were placed into a broader context by a leading member of the UK academic community in the role of rapporteur. This introduction gives a summary of the design choices and strategic planning of Diamond as a coherent user facility, a snapshot of its present status and some consideration of future perspectives. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  2. Structuring of diamond films using microsphere lithography

    Czech Academy of Sciences Publication Activity Database

    Domonkos, Mária; Ižák, Tibor; Štolcová, L.; Proška, J.; Demo, Pavel; Kromka, Alexander

    2014-01-01

    Roč. 54, č. 5 (2014), s. 320-324 ISSN 1210-2709 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : nanostructuring * diamond thin films * polystyrene microspheres * reactive ion etching * scanning electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism

  3. HFCVD Diamond-Coated Mechanical Seals

    Directory of Open Access Journals (Sweden)

    Raul Simões

    2018-05-01

    Full Text Available A mechanical seal promotes the connection between systems or mechanisms, preventing the escape of fluids to the exterior. Nonetheless, due to extreme working conditions, premature failure can occur. Diamond, due to its excellent properties, is heralded as an excellent choice to cover the surface of these devices and extend their lifetime. Therefore, the main objective of this work was to deposit diamond films over mechanical seals and test the coated seals on a water pump, under real working conditions. The coatings were created by hot filament chemical vapor deposition (HFCVD and two consecutive layers of micro- and nanocrystalline diamond were deposited. One of the main difficulties is the attainment of a good adhesion between the diamond films and the mechanical seal material (WC-Co. Nucleation, deposition conditions, and pre-treatments were studied to enhance the coating. Superficial wear or delamination of the film was investigated using SEM and Raman characterization techniques, in order to draw conclusions about the feasibility of these coatings in the WC-Co mechanical seals with the purpose of increasing their performance and life time. The results obtained gave a good indication about the feasibility of this process and the deposition conditions used, with the mechanical seals showing no wear and no film delamination after a real work environment test.

  4. Quantum sensors based on single diamond defects

    International Nuclear Information System (INIS)

    Jelezko Fedor

    2014-01-01

    NV centers in diamond are promising sensors able to detect electric and magnetic fields at nanoscale. Here we report on the detection of biomolecules using magnetic noise induced by their electron and nuclear spins. Presented results show first steps towards establishing novel sensing technology for visualizing single proteins and study of their dynamics. (author)

  5. Grain boundary effects in nanocrystalline diamond

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří J.; Hubík, Pavel; Krištofik, Jozef; Nesládek, Miloš

    2008-01-01

    Roč. 205, č. 9 (2008), 2163-2168 ISSN 1862-6300 R&D Projects: GA ČR(CZ) GA202/06/0040 Institutional research plan: CEZ:AV0Z10100521 Keywords : diamond film * grain boundary * superconductivity * noise * ballistic transport Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.205, year: 2008

  6. Diamond structures grown from polymer composite nanofibers

    Czech Academy of Sciences Publication Activity Database

    Potocký, Štěpán; Kromka, Alexander; Babchenko, Oleg; Rezek, Bohuslav; Martinová, L.; Pokorný, P.

    2013-01-01

    Roč. 5, č. 6 (2013), s. 519-521 ISSN 2164-6627 R&D Projects: GA ČR GAP108/12/0910; GA ČR GAP205/12/0908 Institutional support: RVO:68378271 Keywords : chemical vapour deposition * composite polymer * nanocrystalline diamond * nanofiber sheet * SEM Subject RIV: BM - Solid Matter Physics ; Magnetism

  7. Laser systems with diamond optical elements

    International Nuclear Information System (INIS)

    Seitz, J.R.

    1975-01-01

    High power laser systems with optical elements of diamond having a thermal conductivity of at least 10 W/cm. 0 K at 300 0 K and an optical absorption at the laser beam wavelength of no more than 10 to 20 percent are described. (U.S.)

  8. Trading diamonds for guns | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-07-15

    Jul 15, 2011 ... ... from war zones to Belgian brokers to jewellery stores wasn't easy. ... The UN Security Council began to take a major interest in Sierra Leone and its ... and industry and government to play in the regulatory body for diamonds ...

  9. Tribology: Diamonds are forever - or are they?

    Science.gov (United States)

    Fineberg, Jay

    2011-01-01

    The friction and wear of materials is part of our everyday experience, and yet these processes are not well understood. The example of diamond highlights wear processes that result from bumping atoms, showing that the devil is indeed in the details.

  10. Point contact to single-crystalline diamond

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří J.; Hubík, Pavel; Uxa, Štěpán; Krištofik, Jozef; Kozak, Halyna

    2012-01-01

    Roč. 27, č. 6 (2012), 1-4 ISSN 0268-1242 R&D Projects: GA ČR GAP204/10/0212 Institutional research plan: CEZ:AV0Z10100521 Keywords : point-contact * diamond * space-charge–limited transport Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.921, year: 2012

  11. Diamond-based single-photon emitters

    International Nuclear Information System (INIS)

    Aharonovich, I; Castelletto, S; Simpson, D A; Su, C-H; Greentree, A D; Prawer, S

    2011-01-01

    The exploitation of emerging quantum technologies requires efficient fabrication of key building blocks. Sources of single photons are extremely important across many applications as they can serve as vectors for quantum information-thereby allowing long-range (perhaps even global-scale) quantum states to be made and manipulated for tasks such as quantum communication or distributed quantum computation. At the single-emitter level, quantum sources also afford new possibilities in terms of nanoscopy and bio-marking. Color centers in diamond are prominent candidates to generate and manipulate quantum states of light, as they are a photostable solid-state source of single photons at room temperature. In this review, we discuss the state of the art of diamond-based single-photon emitters and highlight their fabrication methodologies. We present the experimental techniques used to characterize the quantum emitters and discuss their photophysical properties. We outline a number of applications including quantum key distribution, bio-marking and sub-diffraction imaging, where diamond-based single emitters are playing a crucial role. We conclude with a discussion of the main challenges and perspectives for employing diamond emitters in quantum information processing.

  12. Diamond Turning Of Infra-Red Components

    Science.gov (United States)

    Hodgson, B.; Lettington, A. H.; Stillwell, P. F. T. C.

    1986-05-01

    Single point diamond machining of infra-red optical components such as aluminium mirrors, germanium lenses and zinc sulphide domes is potentially the most cost effective method for their manufacture since components may be machined from the blanks to a high surface finish, requiring no subsequent polishing, in a few minutes. Machines for the production of flat surfaces are well established. Diamond turning lathes for curved surfaces however require a high capital investment which can be justified only for research purposes or high volume production. The present paper describes the development of a low cost production machine based on a Bryant Symons diamond turning lathe which is able to machine spherical components to the required form and finish. It employs two horizontal spindles one for the workpiece the other for the tool. The machined radius of curvature is set by the alignment of the axes and the radius of the tool motion, as in conventional generation. The diamond tool is always normal to the workpiece and does not need to be accurately profiled. There are two variants of this basic machine. For machining hemispherical domes the axes are at right angles while for lenses with positive or negative curvature these axes are adjustable. An aspherical machine is under development, based on the all mechanical spherical machine, but in which a ± 2 mm aspherecity may be imposed on the best fit sphere by moving the work spindle under numerical control.

  13. Comparison of natural and synthetic diamond X-ray detectors.

    Science.gov (United States)

    Lansley, S P; Betzel, G T; Metcalfe, P; Reinisch, L; Meyer, J

    2010-12-01

    Diamond detectors are particularly well suited for dosimetry applications in radiotherapy for reasons including near-tissue equivalence and high-spatial resolution resulting from small sensitive volumes. However, these detectors have not become commonplace due to high cost and poor availability arising from the need for high-quality diamond. We have fabricated relatively cheap detectors from commercially-available synthetic diamond fabricated using chemical vapour deposition. Here, we present a comparison of one of these detectors with the only commercially-available diamond-based detector (which uses a natural diamond crystal). Parameters such as the energy dependence and linearity of charge with dose were investigated at orthovoltage energies (50-250 kV), and dose-rate dependence of charge at linear accelerator energy (6 MV). The energy dependence of a synthetic diamond detector was similar to that of the natural diamond detector, albeit with slightly less variation across the energy range. Both detectors displayed a linear response with dose (at 100 kV) over the limited dose range used. The sensitivity of the synthetic diamond detector was 302 nC/Gy, compared to 294 nC/Gy measured for the natural diamond detector; however, this was obtained with a bias of 246.50 V compared to a bias of 61.75 V used for the natural diamond detector. The natural diamond detector exhibited a greater dependency on dose-rate than the synthetic diamond detector. Overall, the synthetic diamond detector performed well in comparison to the natural diamond detector.

  14. High sensitivity thermal sensors on insulating diamond

    Energy Technology Data Exchange (ETDEWEB)

    Job, R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Denisenko, A.V. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Zaitsev, A.M. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Melnikov, A.A. [Belarussian State Univ., Minsk (Belarus). HEII and FD; Werner, M. [VDI/VDE-IT, Teltow (Germany); Fahrner, W.R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices

    1996-12-15

    Diamond is a promising material to develop sensors for applications in harsh environments. To increase the sensitivity of diamond temperature sensors the effect of thermionic hole emission (TE) over an energetic barrier formed in the interface between highly boron-doped p-type and intrinsic insulating diamond areas has been suggested. To study the TE of holes a p-i-p diode has been fabricated and analyzed by electrical measurements in the temperature range between 300 K and 700 K. The experimental results have been compared with numerical simulations of its electrical characteristics. Based on a model of the thermionic emission of carriers into an insulator it has been suggested that the temperature sensitivity of the p-i-p diode on diamond is strongly affected by the re-emission of holes from a group of donor-like traps located at a level of 0.7-1.0 eV above the valence band. The mechanism of thermal activation of the current includes a spatial redistribution of the potential, which results in the TE regime from a decrease of the immobilized charge of the ionized traps within the i-zone of the diode and the correspondent lowering of the forward biased barrier. The characteristics of the p-i-p diode were studied with regard to temperature sensor applications. The temperature coefficient of resistance (TCR=-0.05 K{sup -1}) for temperatures above 600 K is about four times larger than the maximal attainable TCR for conventional boron-doped diamond resistors. (orig.)

  15. Applications of diamond films and related materials; Proceedings of the 1st International Conference, Auburn, AL, Aug. 17-22, 1991

    Science.gov (United States)

    Tzeng, Yonhua (Editor); Yoshikawa, Manasori (Editor); Murakawa, Masao (Editor); Feldman, Albert (Editor)

    1991-01-01

    The present conference discusses the nucleation and growth of diamond from hydrocarbons, the cutting tool performance of CVD thick-film diamond, the characterization of CVD diamond grinding powder, industrial applications of crystalline diamond-coated tools, standardized SEM tribometry of diamond-coated substrates, residual stress in CVD diamond films, the optical properties of CVD diamond films, polycrystalline diamond films for optical applications, and diamond growth on ferrous metals. Also discussed are ion beam-irradiation smoothing of diamond films, electronic circuits on diamond substrates, diamond-laminated surfaces for evaporative spray cooling, electron devices based on the unique properties of diamond, diamond cold cathodes, thin-film diamond microstructure applications, Schottky diodes from flame-grown diamond, diamond films for thermionic applications, methods of diamond nucleation and selective deposition, high-rate/large-area diamond film production, halogen-assisted diamond growth, the economics of diamond technology, and the optical and mechanical properties of diamondlike films.

  16. Preparation of Ti-coated diamond particles by microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Quanchao [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Yunnan Copper Smelting and Processing Complex, Yunnan Copper (Group) CO., LTD., Kunming 650102 (China); International Joint Research Center of Advanced Preparation of Superhard Materials Field, Kunming Academician Workstation of Advanced Preparation of Superhard Materials Field, Kunming 650093 (China); Peng, Jinghui [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); International Joint Research Center of Advanced Preparation of Superhard Materials Field, Kunming Academician Workstation of Advanced Preparation of Superhard Materials Field, Kunming 650093 (China); Xu, Lei, E-mail: xulei_kmust@aliyun.com [National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Mechanical Engineering, University of Washington, Seattle, WA 98195 (United States); International Joint Research Center of Advanced Preparation of Superhard Materials Field, Kunming Academician Workstation of Advanced Preparation of Superhard Materials Field, Kunming 650093 (China); Srinivasakannan, C. [Chemical Engineering Department, The Petroleum Institute, P.O. Box 2533, Abu Dhabi (United Arab Emirates); and others

    2016-12-30

    Highlights: • The Ti-Coated diamond particles have been prepared using by microwave heating. • The uniform and dense coating can be produced, and the TiC species was formed. • With increases the temperature results in the thickness of coating increased. • The coating/diamond interfacial bonding strength increased with temperature increasing until 760 °C, then decreased. - Abstract: Depositing strong carbide-forming elements on diamond surface can dramatically improve the interfacial bonding strength between diamond grits and metal matrix. In the present work, investigation on the preparation of Ti-coated diamond particles by microwave heating has been conducted. The morphology, microstructure, and the chemical composition of Ti-coated diamond particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive x-ray spectrometer (EDX). The thickness of Ti coating was measured and the interfacial binding strength between Ti coating and diamond was analyzed. The results show that the surface of the diamond particles could be successfully coated with Ti, forming a uniform and continuous Ti-coated layer. The TiC was found to form between the surface of diamond particles and Ti-coated layer. The amount of TiC as well as the thickness of coating increased with increasing coating temperature, furthermore, the grain size of the coating also grew gradually. The interfacial bonding strength between coating and diamond was found to be best at the temperature of 760 °C.

  17. Preparation of Ti-coated diamond particles by microwave heating

    International Nuclear Information System (INIS)

    Gu, Quanchao; Peng, Jinghui; Xu, Lei; Srinivasakannan, C.

    2016-01-01

    Highlights: • The Ti-Coated diamond particles have been prepared using by microwave heating. • The uniform and dense coating can be produced, and the TiC species was formed. • With increases the temperature results in the thickness of coating increased. • The coating/diamond interfacial bonding strength increased with temperature increasing until 760 °C, then decreased. - Abstract: Depositing strong carbide-forming elements on diamond surface can dramatically improve the interfacial bonding strength between diamond grits and metal matrix. In the present work, investigation on the preparation of Ti-coated diamond particles by microwave heating has been conducted. The morphology, microstructure, and the chemical composition of Ti-coated diamond particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive x-ray spectrometer (EDX). The thickness of Ti coating was measured and the interfacial binding strength between Ti coating and diamond was analyzed. The results show that the surface of the diamond particles could be successfully coated with Ti, forming a uniform and continuous Ti-coated layer. The TiC was found to form between the surface of diamond particles and Ti-coated layer. The amount of TiC as well as the thickness of coating increased with increasing coating temperature, furthermore, the grain size of the coating also grew gradually. The interfacial bonding strength between coating and diamond was found to be best at the temperature of 760 °C.

  18. Performance and characterisation of CVD diamond coated, sintered diamond and WC-Co cutting tools for dental and micromachining applications

    International Nuclear Information System (INIS)

    Sein, Htet; Ahmed, Waqar; Jackson, Mark; Woodwards, Robert; Polini, Riccardo

    2004-01-01

    Diamond coatings are attractive for cutting processes due to their high hardness, low friction coefficient, excellent wear resistance and chemical inertness. The application of diamond coatings on cemented tungsten carbide (WC-Co) tools was the subject of much attention in recent years in order to improve cutting performance and tool life. WC-Co tools containing 6% Co and 94% WC substrate with an average grain size 1-3 μm were used in this study. In order to improve the adhesion between diamond and WC substrates, it is necessary to etch away the surface Co and prepare the surface for subsequent diamond growth. Hot filament chemical vapour deposition with a modified vertical filament arrangement has been employed for the deposition of diamond films. Diamond film quality and purity have been characterised using scanning electron microscopy and micro-Raman spectroscopy. The performance of diamond coated WC-Co bur, uncoated WC-Co bur, and diamond embedded (sintered) bur have been compared by drilling a series of holes into various materials such as human teeth, borosilicate glass and porcelain teeth. Flank wear has been used to assess the wear rates of the tools. The materials subjected to cutting processes have been examined to assess the quality of the finish. Diamond coated WC-Co microdrills and uncoated microdrills were also tested on aluminium alloys. Results show that there was a 300% improvement when the drills were coated with diamond compared to the uncoated tools

  19. Metastable State Diamond Growth and its Applications to Electronic Devices.

    Science.gov (United States)

    Jeng, David Guang-Kai

    Diamond which consists of a dense array of carbon atoms joined by strong covalent bonds and formed into a tetrahedral crystal structure has remarkable mechanical, thermal, optical and electrical properties suitable for many industrial applications. With a proper type of doping, diamond is also an ideal semiconductor for high performance electronic devices. Unfortunately, natural diamond is rare and limited by its size and cost, it is not surprising that people continuously look for a synthetic replacement. It was believed for long time that graphite, another form of carbon, may be converted into diamond under high pressure and temperature. However, the exact condition of conversion was not clear. In 1939, O. I. Leipunsky developed an equilibrium phase diagram between graphite and diamond based on thermodynamic considerations. In the phase diagram, there is a low temperature (below 1000^ circC) and low pressure (below 1 atm) region in which diamond is metastable and graphite is stable, therefore establishes the conditions for the coexistence of the two species. Leipunsky's pioneer work opened the door for diamond synthesis. In 1955, the General Electric company (GE) was able to produce artificial diamond at 55k atm pressure and a temperature of 2000^ circC. Contrary to GE, B. Derjaguin and B. V. Spitzyn in Soviet Union, developed a method of growing diamonds at 1000^circC and at a much lower pressure in 1956. Since then, researchers, particularly in Soviet Union, are continuously looking for methods to grow diamond and diamond film at lower temperatures and pressures with slow but steady progress. It was only in the early 80's that the importance of growing diamond films had attracted the attentions of researchers in the Western world and in Japan. Recent progress in plasma physics and chemical vapor deposition techniques in integrated electronics technology have pushed the diamond growth in its metastable states into a new era. In this research, a microwave plasma

  20. The Banking Counter-Guarantee. Juridical Regime

    Directory of Open Access Journals (Sweden)

    Postolache Rada

    2009-06-01

    Full Text Available Not so much studied by the specialised literature, the banking counter-guarantee may beconfounded with the other types of guarantee which frequently go with the guaranteed obligation –simple guarantee, collateral guarantee, the confirmation of the guarantee. The counter-guarantee may bean independent or accessory obligation, as the case may be, exclusively governed by its text, accordingto the parties’ will. At the same time, it is a complex juridical act, a contract whose contents cannot beset apart from the contracts connected form an “economic” point of view. The counter-guarantee is theresult of the banking practice and is generated by the need to make amends for the flaws generated bythe direct guarantee. The present research is focused on the analysis of the banking practice, normativeacts, jurisprudence and banking juridical literature.

  1. CORNELL: CLEO's counters

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Particle identification by measuring ionization is complicated by the fact that the energy lost to ionization in passing through matter has large fluctuations, first calculated by Landau. These large fluctuations imply that many measurements must be made in order to determine the most probable ionization value that is characteristic of the particle type. The JADE chamber at PETRA and the TPC chamber at PEP measure both the ionization and the momenta of tracks in the same device. In the CLEO experiment at Cornell's CESR ring, ionization is measured in dedicated energy loss counters contained in each of the eight octants surrounding the drift chamber and superconducting coil. The last of these were installed in the summer of 1981, replacing Cherenkov counters that were used while the energy loss counters were being developed and built

  2. An extended range neutron rem counter

    International Nuclear Information System (INIS)

    Birattari, C.; Nuccetelli, C.; Pelliccioni, M.; Silari, M.

    1990-01-01

    Extensive Monte Carlo calculations have been carried out to assess the possibility of extending the sensitivity of a neutron rem counter of the Andersson-Braun type up to several hundred MeV. The validity of the model adopted has first been checked by comparing with experimental data the calculated response curve and the angular dependence of the sensitivity for a well known commercial rem counter. Next, a number of modifications to the configuration of the moderator-attenuator have been investigated. The response functions and angular distributions produced by two simple solutions yielding an instrument with a sensitivity extended up to 400 MeV are presented. The response of the original rem counter and of its two modified versions to nine test spectra has also been calculated. The resulting instrument is transportable rather than portable, but the availability of an extended range neutron survey meter would be of great advantage at medium and high energy particle accelerator facilities. (orig.)

  3. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A new concept is presented explaining changes in spectrometric parameters of proportional counters which occur due to varying count rate. The basic feature of this concept is that the gas gain of the counter remains constant in a wide range of count rate and that the decrease in the pulse amplitude and the detorioration of the energy resolution observed are the results of changes in the shape of original current pulses generated in the active volume of the counter. In order to confirm the validity of this statement, measurements of the gas amplification factor have been made in a wide count rate range. It is shown that above a certain critical value the gas gain depends on both the operating voltage and the count rate. (author)

  4. Workshop on diamond and diamond-like-carbon films for the transportation industry

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, F.A.; Moores, D.K. [eds.

    1993-01-01

    Applications exist in advanced transportation systems as well as in manufacturing processes that would benefit from superior tribological properties of diamond, diamond-like-carbon and cubic boron nitride coatings. Their superior hardness make them ideal candidates as protective coatings to reduce adhesive, abrasive and erosive wear in advanced diesel engines, gas turbines and spark-ignited engines and in machining and manufacturing tools as well. The high thermal conductivity of diamond also makes it desirable for thermal management not only in tribological applications but also in high-power electronic devices and possibly large braking systems. A workshop has been recently held at Argonne National Laboratory entitled ``Diamond and Diamond-Like-Carbon Films for Transportation Applications`` which was attended by 85 scientists and engineers including top people involved in the basic technology of these films and also representatives from many US industrial companies. A working group on applications endorsed 18 different applications for these films in the transportation area alone. Separate abstracts have been prepared.

  5. Diamond detectors for synchrotron radiation X-ray applications

    Energy Technology Data Exchange (ETDEWEB)

    De Sio, A. [Laboratori Nazionali di Frascati, INFN, 00044 Frascati, Roma (Italy); Department of Astronomy and Space Science, Universita di Firenze, L.go E. Fermi 2, 50125 Firenze (Italy)], E-mail: desio@arcetri.astro.it; Pace, E. [Department of Astronomy and Space Science, Universita di Firenze, L.go E. Fermi 2, 50125 Firenze (Italy); INFN, Sezione di Firenze, v. G. Sansone 1, Sesto Fiorentino, Firenze (Italy); Cinque, G.; Marcelli, A. [Laboratori Nazionali di Frascati, INFN, 00044 Frascati, Roma (Italy); Achard, J.; Tallaire, A. [LIMHP-CNRS, University of Paris XIII, 99 Avenue JB Clement, 93430 Villetaneuse (France)

    2007-07-15

    Due to its unique physical properties, diamond is a very appealing material for the development of electronic devices and sensors. Its wide band gap (5.5 eV) endows diamond based devices with low thermal noise, low dark current levels and, in the case of radiation detectors, high visible-to-X-ray signal discrimination (visible blindness) as well as high sensitivity to energies greater than the band gap. Furthermore, due to its radiation hardness diamond is very interesting for applications in extreme environments, or as monitor of high fluency radiation beams. In this work the use of diamond based detectors for X-ray sensing is discussed. On purpose, some photo-conductors based on different diamond types have been tested at the DAFNE-L synchrotron radiation laboratory at Frascati. X-ray sensitivity spectra, linearity and stability of the response of these diamond devices have been measured in order to evidence the promising performance of such devices.

  6. Diamond based adsorbents and their application in chromatography.

    Science.gov (United States)

    Peristyy, Anton A; Fedyanina, Olga N; Paull, Brett; Nesterenko, Pavel N

    2014-08-29

    The idea of using diamond and diamond containing materials in separation sciences has attracted a strong interest in the past decade. The combination of a unique range of properties, such as chemical inertness, mechanical, thermal and hydrolytic stability, excellent thermal conductivity with minimal thermal expansion and intriguing adsorption properties makes diamond a promising material for use in various modes of chromatography. This review summarises the recent research on the preparation of diamond and diamond based stationary phases, their properties and chromatographic performance. Special attention is devoted to the dominant retention mechanisms evident for particular diamond containing phases, and their subsequent applicability to various modes of chromatography, including chromatography carried out under conditions of high temperature and pressure. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Vertically aligned nanowires from boron-doped diamond.

    Science.gov (United States)

    Yang, Nianjun; Uetsuka, Hiroshi; Osawa, Eiji; Nebel, Christoph E

    2008-11-01

    Vertically aligned diamond nanowires with controlled geometrical properties like length and distance between wires were fabricated by use of nanodiamond particles as a hard mask and by use of reactive ion etching. The surface structure, electronic properties, and electrochemical functionalization of diamond nanowires were characterized by atomic force microscopy (AFM) and scanning tunneling microscopy (STM) as well as electrochemical techniques. AFM and STM experiments show that diamond nanowire etched for 10 s have wire-typed structures with 3-10 nm in length and with typically 11 nm spacing in between. The electrode active area of diamond nanowires is enhanced by a factor of 2. The functionalization of nanowire tips with nitrophenyl molecules is characterized by STM on clean and on nitrophenyl molecule-modified diamond nanowires. Tip-modified diamond nanowires are promising with respect to biosensor applications where controlled biomolecule bonding is required to improve chemical stability and sensing significantly.

  8. Investigation of defects in CVD diamond: Influence for radiotherapy applications

    International Nuclear Information System (INIS)

    Guerrero, M.J.; Tromson, D.; Bergonzo, P.; Barrett, R.

    2005-01-01

    In this study we present the potentialities of CVD diamond as an ionisation chamber for radiotherapy applications. Trapping levels present in CVD diamond are characterised using Thermally Stimulated Current (TSC) method with X-ray sources. The influence of the corresponding defects on the detector response is investigated and compared to those observed in natural diamond. Also, their spatial distribution across a large area polycrystalline diamond ionisation chamber is discussed. Results show the relative influence of two different populations of trapping levels in CVD diamond whose effect is crucial for radiotherapy applications. To partially overcome the defect detrimental effects, we propose to use CVD diamond ionisation chambers at moderate temperatures from 70 to 100 deg. C that could be provided by self heating of the device, for a dramatically improved stability and reproducibility

  9. Use of the diamond to the detection of particles

    International Nuclear Information System (INIS)

    Mer, C.; Tromson, D.; Brambilla, A.; Foulon, F.; Guizard, B.; Bergonzo

    2001-01-01

    Diamond synthesized by chemical vapor deposition (CVD) is a valuable material for the detection of particles: broad forbidden energy band, high mobility of electron-hole pairs, and a short life-time of charge carriers. Diamond layers have been used in alpha detectors or gamma dose ratemeters designed to be used in hostile environment. Diamond presents a high resistance to radiation and corrosion. The properties of diamond concerning the detection of particles are spoilt by the existence of crystal defects even in high quality natural or synthesized diamond. This article presents recent works that have been performed in CEA laboratories in order to optimize the use of CVD diamond in particle detectors. (A.C.)

  10. Diamond detectors for synchrotron radiation X-ray applications

    International Nuclear Information System (INIS)

    De Sio, A.; Pace, E.; Cinque, G.; Marcelli, A.; Achard, J.; Tallaire, A.

    2007-01-01

    Due to its unique physical properties, diamond is a very appealing material for the development of electronic devices and sensors. Its wide band gap (5.5 eV) endows diamond based devices with low thermal noise, low dark current levels and, in the case of radiation detectors, high visible-to-X-ray signal discrimination (visible blindness) as well as high sensitivity to energies greater than the band gap. Furthermore, due to its radiation hardness diamond is very interesting for applications in extreme environments, or as monitor of high fluency radiation beams. In this work the use of diamond based detectors for X-ray sensing is discussed. On purpose, some photo-conductors based on different diamond types have been tested at the DAFNE-L synchrotron radiation laboratory at Frascati. X-ray sensitivity spectra, linearity and stability of the response of these diamond devices have been measured in order to evidence the promising performance of such devices

  11. Protein-modified nanocrystalline diamond thin films for biosensor applications.

    Science.gov (United States)

    Härtl, Andreas; Schmich, Evelyn; Garrido, Jose A; Hernando, Jorge; Catharino, Silvia C R; Walter, Stefan; Feulner, Peter; Kromka, Alexander; Steinmüller, Doris; Stutzmann, Martin

    2004-10-01

    Diamond exhibits several special properties, for example good biocompatibility and a large electrochemical potential window, that make it particularly suitable for biofunctionalization and biosensing. Here we show that proteins can be attached covalently to nanocrystalline diamond thin films. Moreover, we show that, although the biomolecules are immobilized at the surface, they are still fully functional and active. Hydrogen-terminated nanocrystalline diamond films were modified by using a photochemical process to generate a surface layer of amino groups, to which proteins were covalently attached. We used green fluorescent protein to reveal the successful coupling directly. After functionalization of nanocrystalline diamond electrodes with the enzyme catalase, a direct electron transfer between the enzyme's redox centre and the diamond electrode was detected. Moreover, the modified electrode was found to be sensitive to hydrogen peroxide. Because of its dual role as a substrate for biofunctionalization and as an electrode, nanocrystalline diamond is a very promising candidate for future biosensor applications.

  12. Isotopically pure single crystal epitaxial diamond films and their preparation

    International Nuclear Information System (INIS)

    Banholzer, W.F.; Anthony, T.R.; Williams, D.M.

    1992-01-01

    The present invention is directed to the production of single crystal diamond consisting of isotopically pure carbon-12 or carbon-13. In the present invention, isotopically pure single crystal diamond is grown on a single crystal substrate directly from isotopically pure carbon-12 or carbon-13. One method for forming isotopically pure single crystal diamond comprises the steps of placing in a reaction chamber a single substrate heated to an elevated diamond forming temperature. Another method for forming isotopically pure single crystal diamond comprises diffusing isotopically pure carbon-12 or carbon-13 through a metallic catalyst under high pressure to a region containing a single crystal substrate to form an isotopically pure single crystal diamond layer on said single crystal substrate

  13. 78 FR 52363 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Diamond...

    Science.gov (United States)

    2013-08-22

    ... causes of diamond darter habitat loss. Water quality degradation and siltation also played key roles. See... quantitatively define specific water quality standards required by the diamond darter. These organizations noted... conductivity poses to the diamond [[Page 52368

  14. Calibration of nuclear medicine gamma counters

    International Nuclear Information System (INIS)

    Orlic, M.; Spasic-Jokic, V.; Jovanovic, M.; Vranjes, S. . E-mail address of corresponding author: morlic@vin.bg.ac.yu; Orlic, M.)

    2005-01-01

    In this paper the practical problem of nuclear medicine gamma counters calibration has been solved by using dose calibrators CRC-15R with standard error ±5%. The samples from technetium generators have been measured both by dose calibrators CRC-15R and gamma counter ICN Gamma 3.33 taking into account decay correction. Only the linear part of the curve has practical meaning. The advantage of this procedure satisfies the requirements from international standards: the calibration of sources used for medical exposure be traceable to a standard dosimetry laboratory and radiopharmaceuticals for nuclear medicine procedures be calibrated in terms of activity of the radiopharmaceutical to be administered. (author)

  15. Analysis of counter-rotating wind turbines

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Zakkam, Vinod Arun Kumar; Sørensen, Jens Nørkær

    2007-01-01

    This paper presents a study on the performance of a wind turbine with two counter-rotating (CRWT) rotors. The characteristics of the two counter-rotating rotors are on a 3-bladed Nordtank 500 kW rotor. The analysis has been carried out by using an Actuator Line technique implemented in the Navier......-Stokes code EllipSys3D. The analysis shows that the Annual Energy Production can be increased to about 43.5 %, as compared to a wind turbine with a single rotor. In order to determine the optimal settings of the CRWT turbine, parameters such as distance between two rotors and rotational speed have been...

  16. Development of DUPIC safeguards neutron counter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Gil; Cha, Hong Ryul; Kim, Ho Dong; Hong, Jong Sook; Kang, Hee Young

    1999-08-01

    KAERI, in cooperation with LANL, developed DSNC (DUPIC Safeguards Neutron Counter) for safeguards implementing on DUPIC process which is under development by KAERI for direct use of spent PWR fuel in CANDU reactors. DSNC is a well-type neutron coincidence counter with substantial shielding to protect system from high gamma radiation of spent fuel. General development procedures in terms of design, manufacturing, fabrication, cold and hot test, performance test for DSNC authentication by KAERI-IAEA-LANL are described in this report. It is expected that the techniques related DSNC development and associated neutron detection and evaluation method could be applied for safeguards improvement. (Author). 20 refs., 16 tabs. 98 figs.

  17. Counter of radiation in body parts

    International Nuclear Information System (INIS)

    Pollard, D.E.

    1983-01-01

    A new radiation counter for the determination of radiocontaminated body parts has been designed. Composed of several movable detectors, shielded from background radiation and focused on different parts of the human body by narrow apertures in the lead enclosure, the invention provides a quick tool for quantitative and qualitative part-by-part analysis of the body with respect to radiocontamination. The counter can be handled easily by the tested person himself and consequently, it is suitable for mass controls etc. (G.J.P.)

  18. Whole body counters: types, performance and uses

    International Nuclear Information System (INIS)

    Jales, R.L.C.

    1983-01-01

    The present monograph deals with Whole Counters, since its definition, evolution, performance, clinical indications and results. Scintillation crystals detection systems were described as well as scintillant solutions, plastic scintillations, and gaseous detectors, including its interplay forms and basal characteristics. Geometric arrangements of standard chair, arc and hammock, arrangements with scintillant solutions and plastic scintillations, as well as special geometric arrangements were equally commented. Clinic and experimental studies were also dealt with Whole Body Counters, giving examples with potassium, iron vitamin B 12 and albumin. (author)

  19. A study of defects in diamond

    International Nuclear Information System (INIS)

    Hunt, D.C.

    1999-01-01

    Defects, intrinsic and extrinsic, in natural and synthetic diamond, have been studied using Electron Paramagnetic Resonance (EPR) and optical absorption techniques. EPR measurements have been used in conjunction with infrared absorption to identify the defect-induced one-phonon infrared spectra produced by ionised single substitutional nitrogen, N s + . This N s + spectrum is characterised by a sharp peak at the Raman energy, 1332 cm -1 , accompanied by several broader resonances at 950(5), 1050(5), and 1095(5) cm -1 . Detailed concentration measurements show that a concentration of 5.5(5) ppm gives rise to an absorption of 1 cm -1 at 1332 cm -1 . The optical absorption band ND1, identified as the negative vacancy (V - ), is frequently used by diamond spectroscopists to measure the concentration of V - . Isoya has identified V - in the EPR spectra of irradiated diamond. The accuracy of EPR in determining concentrations, has been used to correlate the integrated absorption of the ND1 zero-phonon line to the concentration of V - centres. The parameter derived from this correlation is ∼16 times smaller than the previously accepted value obtained by indirect methods. A systematic study has been made - using EPR and optical absorption techniques - of synthetic type IIa diamonds, which have been irradiated with 2 MeV electrons in a specially developed dewar, allowing irradiation down to a measured sample temperature of 100K. Measurement of defect creation rates of the neutral vacancy and EPR defects, show a radical difference in the production rate of the EPR defect R2 between irradiation with the sample held at 100K and 350K. At 100K its production rate is 1.1(1) cm -1 , ∼10 times greater that at 350K. Observation of the di- -split interstitial (Ri) after irradiation at 100K proves the self-interstitial in diamond must be mobile at 100K, under the conditions of irradiation. Further study of the properties of the R2 defect (the most dominant EPR after electron

  20. Characterization of boron doped nanocrystalline diamonds

    International Nuclear Information System (INIS)

    Peterlevitz, A C; Manne, G M; Sampaio, M A; Quispe, J C R; Pasquetto, M P; Iannini, R F; Ceragioli, H J; Baranauskas, V

    2008-01-01

    Nanostructured diamond doped with boron was prepared using a hot-filament assisted chemical vapour deposition system fed with an ethyl alcohol, hydrogen and argon mixture. The reduction of the diamond grains to the nanoscale was produced by secondary nucleation and defects induced by argon and boron atoms via surface reactions during chemical vapour deposition. Raman measurements show that the samples are nanodiamonds embedded in a matrix of graphite and disordered carbon grains, while morphological investigations using field electron scanning microscopy show that the size of the grains ranges from 20 to 100 nm. The lowest threshold fields achieved were in the 1.6 to 2.4 V/μm range

  1. Dislocation density and graphitization of diamond crystals

    International Nuclear Information System (INIS)

    Pantea, C.; Voronin, G.A.; Zerda, T.W.; Gubicza, J.; Ungar, T.

    2002-01-01

    Two sets of diamond specimens compressed at 2 GPa at temperatures varying between 1060 K and 1760 K were prepared; one in which graphitization was promoted by the presence of water and another in which graphitization of diamond was practically absent. X-ray diffraction peak profiles of both sets were analyzed for the microstructure by using the modified Williamson-Hall method and by fitting the Fourier coefficients of the measured profiles by theoretical functions for crystallite size and lattice strain. The procedures determined mean size and size distribution of crystallites as well as the density and the character of the dislocations. The same experimental conditions resulted in different microstructures for the two sets of samples. They were explained in terms of hydrostatic conditions present in the graphitized samples

  2. Precision diamond grinding of ceramics and glass

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Diamond turning on advanced machine tool prototypes

    International Nuclear Information System (INIS)

    Arnold, J.B.; Steger, P.J.

    1975-01-01

    Specular-quality metal mirrors are being machined for use in laser optical systems. The fabrication process incorporates special quality diamond tools and specially constructed turning machines. The machines are controlled by advanced control techniques and are housed in an environmentally controlled laboratory to insure ultimate machine stability and positional accuracy. The materials from which these mirrors are primarily produced are the softer face-center-cubic structure metals, such as gold, silver, copper, and aluminum. Mirror manufacturing by the single-point diamond machining process is in an early stage of development, but it is anticipated that this method will become the most economical way for producing high-quality metal mirrors. (U.S.)

  4. Diamond wire cutting of heat exchangers

    International Nuclear Information System (INIS)

    Beckman, T.R.; Bjerler, J.

    1991-01-01

    With the change-out of equipment at nuclear power plants comes large quantities of low level contaminated metallic waste. Of particular concern are large heat exchangers, preheaters and steam generators. These bulky items consume huge volumes of burial space. The need for volume reduction and recycling of these metals has created new demands for 'how' to cut heat exchangers into useful sizes for decontamination, melting or compaction. This paper reviews the cutting solution provided by a diamond wire system, with particular regard for cutting of a Ringhals Preheater Bundle at Studsvik Nuclear in 1989. The background of diamond wire sawing is discussed and basic components of wire sawing are explained. Other examples of wire cutting decommissioned components are also given. (author)

  5. Measurement of tool forces in diamond turning

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Property of the diamond radiation detector

    International Nuclear Information System (INIS)

    Sochor, V.; Cechak, T.; Sopko, B.

    2008-01-01

    The outstanding properties of diamond, such as radiation hardness, high carrier mobility, high band gap and breakdown field, distinguish it as a good candidate for radiation detectors. In the dosimetry for radiotherapy is permanently searched the detector with high sensitivity, high stability, linear dependence of the response, small size, tissue equivalent material and fast response, for the measuring of the temporal and space variations of the dose. The diamond detector properties as high sensitivity, good spatial and temporal resolution, low Leakage currents, low capacitance, possibility to fabricate robust and compact device and high temperature operation make it possible to use these detectors in many fields from high energy physics till radiation monitoring, from Medical therapy dosimetry till synchrotron radiation measurement. (authors)

  7. Cluster Ion Implantation in Graphite and Diamond

    DEFF Research Database (Denmark)

    Popok, Vladimir

    2014-01-01

    Cluster ion beam technique is a versatile tool which can be used for controllable formation of nanosize objects as well as modification and processing of surfaces and shallow layers on an atomic scale. The current paper present an overview and analysis of data obtained on a few sets of graphite...... and diamond samples implanted by keV-energy size-selected cobalt and argon clusters. One of the emphases is put on pinning of metal clusters on graphite with a possibility of following selective etching of graphene layers. The other topic of concern is related to the development of scaling law for cluster...... implantation. Implantation of cobalt and argon clusters into two different allotropic forms of carbon, namely, graphite and diamond is analysed and compared in order to approach universal theory of cluster stopping in matter....

  8. Nanocrystalline diamond coatings for mechanical seals applications.

    Science.gov (United States)

    Santos, J A; Neto, V F; Ruch, D; Grácio, J

    2012-08-01

    A mechanical seal is a type of seal used in rotating equipment, such as pumps and compressors. It consists of a mechanism that assists the connection of the rotating shaft to the housings of the equipments, preventing leakage or avoiding contamination. A common cause of failure of these devices is end face wear out, thus the use of a hard, smooth and wear resistant coating such as nanocrystalline diamond would be of great importance to improve their working performance and increase their lifetime. In this paper, different diamond coatings were deposited by the HFCVD process, using different deposition conditions. Additionally, the as-grown films were characterized for, quality, morphology and microstructure using scanning electron microscopy (SEM) and Raman spectroscopy. The topography and the roughness of the films were characterized by atomic force microscopy (AFM).

  9. Diamond window and its application to ITER gyrotron

    International Nuclear Information System (INIS)

    Sakamoto, K.

    1999-01-01

    On the background of having to reduce the overall cost for ITER to 50% it is proposed to replace conventional glass windows on gyrotrons by diamonds. The successful production and testing of such diamond windows is reported. A diamond window can transmit 5 times more power than usual double disk transmission windows while only costing 3 times as much. As a tradeoff, the gyrotrons could be replaced by more powerful ones and one would need fewer of them

  10. Diamond deposition using a planar radio frequency inductively coupled plasma

    Science.gov (United States)

    Bozeman, S. P.; Tucker, D. A.; Stoner, B. R.; Glass, J. T.; Hooke, W. M.

    1995-06-01

    A planar radio frequency inductively coupled plasma has been used to deposit diamond onto scratched silicon. This plasma source has been developed recently for use in large area semiconductor processing and holds promise as a method for scale up of diamond growth reactors. Deposition occurs in an annulus which coincides with the area of most intense optical emission from the plasma. Well-faceted diamond particles are produced when the substrate is immersed in the plasma.

  11. A CVD diamond beam telescope for charged particle tracking

    CERN Document Server

    Adam, W; Bergonzo, P; de Boer, Wim; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Dulinski, W; Doroshenko, J; Doucet, M; van Eijk, B; Fallou, A; Fischer, P; Fizzotti, F; Kania, D R; Gan, K K; Grigoriev, E; Hallewell, G D; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kaplon, J; Kass, R; Keil, M; Knöpfle, K T; Koeth, T W; Krammer, Manfred; Meuser, S; Lo Giudice, A; MacLynne, L; Manfredotti, C; Meier, D; Menichelli, D; Mishina, M; Moroni, L; Noomen, J; Oh, A; Pan, L S; Pernicka, Manfred; Perera, L P; Riester, J L; Roe, S; Rudge, A; Russ, J; Sala, S; Sampietro, M; Schnetzer, S; Sciortino, S; Stelzer, H; Stone, R; Suter, B; Trischuk, W; Tromson, D; Vittone, E; Weilhammer, Peter; Wermes, N; Wetstein, M; Zeuner, W; Zöller, M

    2002-01-01

    CVD diamond is a radiation hard sensor material which may be used for charged particle tracking near the interaction region in experiments at high luminosity colliders. The goal of the work described here is to investigate the use of several detector planes made of CVD diamond strip sensors for charged particle tracking. Towards this end a tracking telescope composed entirely of CVD diamond planes has been constructed. The telescope was tested in muon beams and its tracking capability has been investigated.

  12. Diamond-based structures to collect and guide light

    Energy Technology Data Exchange (ETDEWEB)

    Castelletto, S [Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Mail H 34 Hawthorn, VIC 3122 (Australia); Harrison, J P; Marseglia, L; Stanley-Clarke, A C; Hadden, J P; Ho, Y-L D; O' Brien, J L; Rarity, J G [Centre for Quantum Photonics, H H Wills Physics Laboratory and Department of Electrical and Electronic Engineering, University of Bristol, Merchant Venturers Building, Woodland Road, Bristol BS8 1UB (United Kingdom); Gibson, B C; Fairchild, B A; Ganesan, K; Huntington, S T; Greentree, A D; Prawer, S [School of Physics, University of Melbourne, Melbourne VIC 3010 (Australia); Hiscocks, M P; Ladouceur, F, E-mail: scastelletto@swin.edu.au, E-mail: luca.marseglia@bristol.ac.uk [School of EE and T, University of New South Wales, Sydney, NSW 2052 (Australia)

    2011-02-15

    We examine some promising photonic structures for collecting and guiding light in bulk diamond. The aim of this work is to optimize single photon sources and single spin read-out from diamond color centers, specifically NV{sup -} centers. We review the modeling and fabrication (by focused ion beam and reactive ion etching) of solid immersion lenses, waveguides and photonic crystal cavities in monolithic diamond.

  13. Method to fabricate micro and nano diamond devices

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-04-11

    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.

  14. 3D characterisation of tool wear whilst diamond turning silicon

    OpenAIRE

    Durazo-Cardenas, Isidro Sergio; Shore, Paul; Luo, X.; Jacklin, T.; Impey, S. A.; Cox, A.

    2006-01-01

    Nanometrically smooth infrared silicon optics can be manufactured by the diamond turning process. Due to its relatively low density, silicon is an ideal optical material for weight sensitive infrared (IR) applications. However, rapid diamond tool edge degradation and the effect on the achieved surface have prevented significant exploitation. With the aim of developing a process model to optimise the diamond turning of silicon optics, a series of experimental trials were devi...

  15. Nanomechanical resonant structures in single-crystal diamond

    OpenAIRE

    Burek, Michael J.; Ramos, Daniel; Patel, Parth; Frank, Ian W.; Lončar, Marko

    2013-01-01

    With its host of outstanding material properties, single-crystal diamond is an attractive material for nanomechanical systems. Here, the mechanical resonance characteristics of freestanding, single-crystal diamond nanobeams fabricated by an angled-etching methodology are reported. Resonance frequencies displayed evidence of significant compressive stress in doubly clamped diamond nanobeams, while cantilever resonance modes followed the expected inverse-length-squared trend. Q-factors on the o...

  16. Signaling Pathways in Pathogenesis of Diamond Blackfan Anemia

    Science.gov (United States)

    2015-12-01

    AWARD NUMBER: W81XWH-12-1-0590 TITLE: SIGNALING PATHWAYS IN PATHOGENESIS OF DIAMOND BLACKFAN ANEMIA PRINCIPAL INVESTIGATOR: KATHLEEN M...SUBTITLE 5a. CONTRACT NUMBER W81XWH-12-1-0590 SIGNALING PATHWAYS IN PATHOGENESIS OF DIAMOND BLACKFAN ANEMIA 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...Unlimited 13. SUPPLEMENTARY NOTES None 14. ABSTRACT: Diamond Blackfan Anemia (DBA) is a disorder that results in pure red cell aplasia, congenital

  17. Photovoltage effects in polypyrrole-diamond nanosystem

    Czech Academy of Sciences Publication Activity Database

    Rezek, Bohuslav; Čermák, Jan; Kromka, Alexander; Ledinský, Martin; Kočka, Jan

    2009-01-01

    Roč. 18, 2-3 (2009), 249-252 ISSN 0925-9635 R&D Projects: GA MŠk(CZ) LC06040; GA AV ČR KAN400100701; GA ČR(CZ) GD202/05/H003; GA MŠk LC510 Institutional research plan: CEZ:AV0Z10100521 Keywords : diamond * polymers * heterojunction * Kelvin force microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.822, year: 2009

  18. Influence of defects on diamond detection properties

    International Nuclear Information System (INIS)

    Tromson, Dominique

    2000-01-01

    This work focuses on the study of the influence of defects on the detection properties of diamond. Devices are fabricated using natural as well as synthetic diamond samples grown using the plasma enhanced chemical vapour deposition (CVD). Optical studies with infrared and Raman spectrometry are used to characterise the material properties as well as thermoluminescence and thermally stimulated current measurements. These thermally stimulated analyses reveal the presence of several trapping levels with emission temperatures below or near room temperature as well as an important level near 550 K. The influence of these defects on the alpha and X-ray detector responses is studied as a function of the initial state of the detectors (thermal treatment, irradiation) and of the measurement conditions (time, temperature). The results show a significant correlation between the charged state of traps, namely filled or empty and the response of the detectors. It appears that filling and emptying the traps respectively enhances the sensitivity and stability of detection devices to be used at room temperature and decreases the detection properties at higher temperature. Localised measurements are also used to study the spatial inhomogeneity of natural and CVD diamond samples from the 2D mapping of the detector responses. Non uniformity are attributed to a non-isotropic distribution of defects in natural diamonds. By comparing the detector responses to the topographical map of CVD samples a correlation appears between grains and grain boundaries with the variation of the detector sensitivity. Devices fabricated for detection applications with CVD samples are presented and namely for the monitoring and profiling of synchrotron beams as well as dose rate measurements in harsh environments. (author) [fr

  19. Application of diamond tools when decontaminating concrete

    International Nuclear Information System (INIS)

    Woods, B.L.; Gossett, R.F.

    1980-01-01

    The utilization of diamond concrete cutting tools offers new potential approaches to the recurring problems of removing contaminated concrete. Innovative techniques can provide exacting removal within a dust-free environment. Present day technology allows remote control operated equipment to perform tasks heretofore considered impossible. Experience gained from years of removing concrete within the construction industry hopefully can contribute new and improved methods to D and D projects

  20. Fermi level on hydrogen terminated diamond surfaces

    Czech Academy of Sciences Publication Activity Database

    Rezek, Bohuslav; Saurer, C.; Nebel, C. E.; Stutzmann, M.; Ristein, J.; Ley, L.; Snidero, E.; Bergonzo, P.

    2003-01-01

    Roč. 82, č. 14 (2003), s. 2266-2268 ISSN 0003-6951 EU Projects: European Commission(XE) HPRN-CT-1999-00139 Grant - others:DFC(DE) NE524-2 Institutional research plan: CEZ:AV0Z1010914 Keywords : atomic force microscope (AFM) * Kelvin probe experiments * diamond surface Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.049, year: 2003

  1. Diamond surface: atomic and electronic structure

    International Nuclear Information System (INIS)

    Pate, B.B.

    1984-01-01

    Experimental studies of the diamond surface (with primary emphasis on the (111) surface) are presented. Aspects of the diamond surface which are addressed include (1) the electronic structure, (2) the atomic structure, and (3) the effect of termination of the lattice by foreign atoms. Limited studies of graphite are discussed for comparison with the diamond results. Experimental results from valence band and core level photoemission spectroscopy (PES), Auger electron spectroscopy (AES), low energy electron diffraction (LEED), and carbon 1s near edge x-ray absorption fine structure (NEXAFS) spectroscopy (both the total electron yield (TEY) and Auger electron yield (AEY) techniques) are used to study and characterize both the clean and hydrogenated surface. In addition, the interaction of hydrogen with the diamond surface is examined using results from vibrational high resolution low energy electron loss spectroscopy (in collaboration with Waclawski, Pierce, Swanson, and Celotta at the National Bureau of Standards) and photon stimulated ion desorption (PSID) yield at photon energies near the carbon k-edge (hv greater than or equal to 280 eV). Both EELS and PSID verify that the mechanically polished 1 x 1 surface is hydrogen terminated and also that the reconstructed surface is hydrogen free. The (111) 2 x 2/2 x 1 reconstructed surface is obtained from the hydrogenated (111) 1 x 1:H surface by annealing to approx. = 1000 0 C. We observe occupied intrinsic surface states and a surface chemical shift (0.95 +- 0.1 eV) to lower binding energy of the carbon 1s level on the hydrogen-free reconstructed surface. Atomic hydrogen is found to be reactive with the reconstructed surface, while molecular hydrogen is relatively inert. Exposure of the reconstructed surface to atomic hydrogen results in chemisorption of hydrogen and removal of the intrinsic surface state emission in and near the band gap region

  2. Noble gas studies in vapor-growth diamonds: Comparison with shock-produced diamonds and the origin of diamonds in ureilites

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Junichi; Fukunaga, Kazuya; Ito, Keisuke (Kobe Univ. (Japan))

    1991-07-01

    The authors synthesized vapor-trowth diamonds by two kinds of Chemical Vapor Deposition (CVD) using microwave (MWCVD) and hot filament (HFCVD) ionization of gases, and examined elemental abundances and isotopic compositions of the noble gases trapped in the diamonds. It is remarkable that strong differences existed in the noble gas concentrations in the two kinds of CVD diamonds: large amounts of noble gases were trapped in the MWCVD diamonds, but not in the HFCVD diamonds. The heavy noble gases (Ar to Xe) in the MWCVD diamonds were highly fractionated compared with those in the ambient atmosphere, and are in good agreement with the calculated fractionation patterns for plasma at an electron temperature of 7,000-9,000 K. These results strongly suggest that the trapping mechanism of noble gases in CVD diamonds is ion implantation during diamond growth. The degrees of fractionation of heavy noble gases were also in good agreement with those in ureilites. The vapor-growth hypothesis is discussed in comparison with the impact-shock hypothesis as a better model for the origin of diamonds in ureilites. The diamond (and graphite, amorphous carbon, too) may have been deposited on early condensates such as Re, Ir, W, etc. This model explains the chemical features of vein material in ureilites; the refractory siderophile elements are enriched in carbon and noble gases and low in normal siderophiles. The vapor-growth model is also compatible with the oxygen isotopic data of ureilites which suggests that nebular processes are primarily responsible for the composition of ureilites.

  3. Effect of four over-the-counter tooth-whitening products on enamel microhardness.

    Science.gov (United States)

    Majeed, A; Grobler, S R; Moola, M H; Oberholzer, T G

    2011-10-01

    This in vitro study evaluated the effect of four over-the-counter tooth-whitening products on enamel microhardness. Fifty enamel blocks were prepared from extracted human molar teeth. The enamel surfaces were polished up to 1200 grit fineness and the specimens randomly divided into five groups. Enamel blocks were exposed to: Rapid White (n=10); Absolute White (n=10); Speed White (n=10) and White Glo (n=10) whitening products, according to the manufacturers' instructions. As control, ten enamel blocks were kept in artificial saliva at 37 degrees C without any treatment. Microhardness values were obtained before exposure (baseline) and after 1, 7 and 14-day treatment periods using a digital hardness tester with a Vickers diamond indenter. Data were analysed using Wilcoxon Signed Rank Sum Test, one-way ANOVA and Tukey-Kramer Multiple Comparison Test (penamel microhardness. Speed White increased the microhardness of enamel, while White Glo and artificial saliva had no effect on hardness. Over-the-counter tooth-whitening products might decrease enamel microhardness depending on the type of product.

  4. Demonstrating diamond wire cutting of the TFTR

    International Nuclear Information System (INIS)

    Rule, K.; Perry, E.; Larson, S.; Viola, M.

    2000-01-01

    The Tokamak Fusion Test Reactor (TFTR) ceased operation in April 1997 and decommissioning commenced in October 1999. The deuterium-tritium fusion experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the Tokamak (100 cubic meters) present a unique and challenging task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement of fission reactors. This technology is typically used because of its faster cutting times. Alternatively, an innovative approach for dismantlement of the TFTR is the use of diamond wire cutting technology. Recent improvements in diamond wire technology have allowed the cutting of carbon steel components such as pipe, plate, and tube bundles in heat exchangers. Some expected benefits of this technology include: significantly reduction in airborne contaminates, reduced personnel exposure, a reduced risk of spread of tritium contamination, and reduced overall costs as compared to using plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration that was completed in September of 1999, on a mock-up of this complex reactor. The results will identify cost, safety, industrial and engineering parameters, and the related performance of each situation

  5. Long-term data storage in diamond

    Science.gov (United States)

    Dhomkar, Siddharth; Henshaw, Jacob; Jayakumar, Harishankar; Meriles, Carlos A.

    2016-01-01

    The negatively charged nitrogen vacancy (NV−) center in diamond is the focus of widespread attention for applications ranging from quantum information processing to nanoscale metrology. Although most work so far has focused on the NV− optical and spin properties, control of the charge state promises complementary opportunities. One intriguing possibility is the long-term storage of information, a notion we hereby introduce using NV-rich, type 1b diamond. As a proof of principle, we use multicolor optical microscopy to read, write, and reset arbitrary data sets with two-dimensional (2D) binary bit density comparable to present digital-video-disk (DVD) technology. Leveraging on the singular dynamics of NV− ionization, we encode information on different planes of the diamond crystal with no cross-talk, hence extending the storage capacity to three dimensions. Furthermore, we correlate the center’s charge state and the nuclear spin polarization of the nitrogen host and show that the latter is robust to a cycle of NV− ionization and recharge. In combination with super-resolution microscopy techniques, these observations provide a route toward subdiffraction NV charge control, a regime where the storage capacity could exceed present technologies. PMID:27819045

  6. Long-term data storage in diamond.

    Science.gov (United States)

    Dhomkar, Siddharth; Henshaw, Jacob; Jayakumar, Harishankar; Meriles, Carlos A

    2016-10-01

    The negatively charged nitrogen vacancy (NV - ) center in diamond is the focus of widespread attention for applications ranging from quantum information processing to nanoscale metrology. Although most work so far has focused on the NV - optical and spin properties, control of the charge state promises complementary opportunities. One intriguing possibility is the long-term storage of information, a notion we hereby introduce using NV-rich, type 1b diamond. As a proof of principle, we use multicolor optical microscopy to read, write, and reset arbitrary data sets with two-dimensional (2D) binary bit density comparable to present digital-video-disk (DVD) technology. Leveraging on the singular dynamics of NV - ionization, we encode information on different planes of the diamond crystal with no cross-talk, hence extending the storage capacity to three dimensions. Furthermore, we correlate the center's charge state and the nuclear spin polarization of the nitrogen host and show that the latter is robust to a cycle of NV - ionization and recharge. In combination with super-resolution microscopy techniques, these observations provide a route toward subdiffraction NV charge control, a regime where the storage capacity could exceed present technologies.

  7. Demonstrating diamond wire cutting of the TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Rule, K.; Perry, E.; Larson, S.; Viola, M. [and others

    2000-02-24

    The Tokamak Fusion Test Reactor (TFTR) ceased operation in April 1997 and decommissioning commenced in October 1999. The deuterium-tritium fusion experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the Tokamak (100 cubic meters) present a unique and challenging task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement of fission reactors. This technology is typically used because of its faster cutting times. Alternatively, an innovative approach for dismantlement of the TFTR is the use of diamond wire cutting technology. Recent improvements in diamond wire technology have allowed the cutting of carbon steel components such as pipe, plate, and tube bundles in heat exchangers. Some expected benefits of this technology include: significantly reduction in airborne contaminates, reduced personnel exposure, a reduced risk of spread of tritium contamination, and reduced overall costs as compared to using plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration that was completed in September of 1999, on a mock-up of this complex reactor. The results will identify cost, safety, industrial and engineering parameters, and the related performance of each situation.

  8. TSC response of irradiated CVD diamond films

    CERN Document Server

    Borchi, E; Bucciolini, M; Guasti, A; Mazzocchi, S; Pirollo, S; Sciortino, S

    1999-01-01

    CVD diamond films have been irradiated with electrons, sup 6 sup 0 Co photons and protons in order to study the dose response to exposure to different particles and energies and to investigate linearity with dose. The Thermally Stimulated Current (TSC) has been studied as a function of the dose delivered to polymethilmetacrilate (PMMA) in the range from 1 to 12 Gy with 20 MeV electrons from a linear accelerator. The TSC spectrum has revealed the presence of two components with peak temperatures of about 470 and 520 K, corresponding to levels lying in the diamond band gap with activation energies of the order of 0.7 - 1 eV. After the subtraction of the exponential background the charge emitted during the heating scan has been evaluated and has been found to depend linearly on the dose. The thermally emitted charge of the CVD diamond films has also been studied using different particles. The samples have been irradiated with the same PMMA dose of about 2 Gy with 6 and 20 MeV electrons from a Linac, sup 6 sup 0 ...

  9. High collection efficiency CVD diamond alpha detectors

    International Nuclear Information System (INIS)

    Bergonzo, P.; Foulon, F.; Marshall, R.D.; Jany, C.; Brambilla, A.; McKeag, R.D.; Jackman, R.B.

    1998-01-01

    Advances in Chemical Vapor Deposited (CVD) diamond have enabled the routine use of this material for sensor device fabrication, allowing exploitation of its unique combination of physical properties (low temperature susceptibility (> 500 C), high resistance to radiation damage (> 100 Mrad) and to corrosive media). A consequence of CVD diamond growth on silicon is the formation of polycrystalline films which has a profound influence on the physical and electronic properties with respect to those measured on monocrystalline diamond. The authors report the optimization of physical and geometrical device parameters for radiation detection in the counting mode. Sandwich and co-planar electrode geometries are tested and their performances evaluated with regard to the nature of the field profile and drift distances inherent in such devices. The carrier drift length before trapping was measured under alpha particles and values as high as 40% of the overall film thickness are reported. Further, by optimizing the device geometry, they show that a gain in collection efficiency, defined as the induced charge divided by the deposited charge within the material, can be achieved even though lower bias values are used

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Diamond network: template-free fabrication and properties.

    Science.gov (United States)

    Zhuang, Hao; Yang, Nianjun; Fu, Haiyuan; Zhang, Lei; Wang, Chun; Huang, Nan; Jiang, Xin

    2015-03-11

    A porous diamond network with three-dimensionally interconnected pores is of technical importance but difficult to be produced. In this contribution, we demonstrate a simple, controllable, and "template-free" approach to fabricate diamond networks. It combines the deposition of diamond/β-SiC nanocomposite film with a wet-chemical selective etching of the β-SiC phase. The porosity of these networks was tuned from 15 to 68%, determined by the ratio of the β-SiC phase in the composite films. The electrochemical working potential and the reactivity of redox probes on the diamond networks are similar to those of a flat nanocrystalline diamond film, while their surface areas are hundreds of times larger than that of a flat diamond film (e.g., 490-fold enhancement for a 3 μm thick diamond network). The marriage of the unprecedented physical/chemical features of diamond with inherent advantages of the porous structure makes the diamond network a potential candidate for various applications such as water treatment, energy conversion (batteries or fuel cells), and storage (capacitors), as well as electrochemical and biochemical sensing.

  12. Drilling of optical glass with electroplated diamond tools

    Science.gov (United States)

    Wang, A. J.; Luan, C. G.; Yu, A. B.

    2010-10-01

    K9 optical glass drilling experiments were carried out. Bright nickel electroplated diamond tools with small slots and under heat treatment in different temperature were fabricated. Scan electro microscope was applied to analyze the wear of electroplated diamond tool. The material removal rate and grinding ratio were calculated. Machining quality was observed. Bond coating hardness was measured. The experimental results show that coolant is needed for the drilling processes of optical glasses. Heat treatment temperature of diamond tool has influence on wearability of diamond tool and grinding ratio. There were two wear types of electroplated diamond tool, diamond grit wear and bond wear. With the machining processes, wear of diamond grits included fracture, blunt and pull-out, and electroplated bond was gradually worn out. High material removal rates could be obtained by using diamond tool with suitable slot numbers. Bright nickel coating bond presents smallest grains and has better mechanical properties. Bright nickel electroplated diamond tool with slot structure and heat treatment under 200°C was suitable for optical glass drilling.

  13. Alluvial diamond resource potential and production capacity assessment of Mali

    Science.gov (United States)

    Chirico, Peter G.; Barthelemy, Francis; Kone, Fatiaga

    2010-01-01

    In May of 2000, a meeting was convened in Kimberley, South Africa, and attended by representatives of the diamond industry and leaders of African governments to develop a certification process intended to assure that rough, exported diamonds were free of conflictual concerns. This meeting was supported later in 2000 by the United Nations in a resolution adopted by the General Assembly. By 2002, the Kimberley Process Certification Scheme (KPCS) was ratified and signed by diamond-producing and diamond-importing countries. Over 70 countries were included as members of the KPCS at the end of 2007. To prevent trade in "conflict diamonds" while protecting legitimate trade, the KPCS requires that each country set up an internal system of controls to prevent conflict diamonds from entering any imported or exported shipments of rough diamonds. Every diamond or diamond shipment must be accompanied by a Kimberley Process (KP) certificate and be contained in tamper-proof packaging. The objective of this study was (1) to assess the naturally occurring endowment of diamonds in Mali (potential resources) based on geological evidence, previous studies, and recent field data and (2) to assess the diamond-production capacity and measure the intensity of mining activity. Several possible methods can be used to estimate the potential diamond resource. However, because there is generally a lack of sufficient and consistent data recording all diamond mining in Mali and because time to conduct fieldwork and accessibility to the diamond mining areas are limited, four different methodologies were used: the cylindrical calculation of the primary kimberlitic deposits, the surface area methodology, the volume and grade approach, and the content per kilometer approach. Approximately 700,000 carats are estimated to be in the alluvial deposits of the Kenieba region, with 540,000 carats calculated to lie within the concentration grade deposits. Additionally, 580,000 carats are estimated to have

  14. The development of diamond tracking detectors for the LHC

    International Nuclear Information System (INIS)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Boer, W. de; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Doroshenko, J.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fischer, P.; Fizzotti, F.; Furetta, C.; Gan, K.K.; Ghodbane, N.; Grigoriev, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kaplon, J.; Karl, C.; Kass, R.; Keil, M.; Knoepfle, K.T.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Menichelli, D.; Meuser, S.; Mishina, M.; Moroni, L.; Noomen, J.; Oh, A.; Perera, L.; Pernegger, H.; Pernicka, M.; Polesello, P.; Potenza, R.; Riester, J.L.; Roe, S.; Rudge, A.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Sutera, C.; Trischuk, W.; Tromson, D.; Tuve, C.; Vincenzo, B.; Weilhammer, P.; Wermes, N.; Wetstein, M.; Zeuner, W.; Zoeller, M.

    2003-01-01

    Chemical vapor deposition diamond has been discussed extensively as an alternate sensor material for use very close to the interaction region of the LHC where extreme radiation conditions exist. During the last few years diamond devices have been manufactured and tested with LHC electronics with the goal of creating a detector usable by all LHC experiment. Extensive progress on diamond quality, on the development of diamond trackers and on radiation hardness studies has been made. Transforming the technology to the LHC specific requirements is now underway. In this paper we present the recent progress achieved

  15. New developments in CVD diamond for detector applications

    Science.gov (United States)

    Adam, W.; Berdermann, E.; Bergonzo, P.; de Boer, W.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Dulinski, W.; Doroshenko, J.; van Eijk, B.; Fallou, A.; Fischer, P.; Fizzotti, F.; Furetta, C.; Gan, K. K.; Ghodbane, N.; Grigoriev, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kaplon, J.; Kass, R.; Keil, M.; Knoepfle, K. T.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D.; Menichelli, D.; Meuser, S.; Mishina, M.; Moroni, L.; Noomen, J.; Oh, A.; Pernicka, M.; Perera, L.; Potenza, R.; Riester, J. L.; Roe, S.; Rudge, A.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Sutera, C.; Trischuk, W.; Tromson, D.; Tuve, C.; Vincenzo, B.; Weilhammer, P.; Wermes, N.; Wetstein, M.; Zeuner, W.; Zoeller, M.

    Chemical Vapor Deposition (CVD) diamond has been discussed extensively as an alternative sensor material for use very close to the interaction region of the LHC and other machines where extreme radiation conditions exist. During the last seven years the RD42 collaboration has developed diamond detectors and tested them with LHC electronics towards the end of creating a device usable by experiments. The most recent results of this work are presented. Recently, a new form of CVD diamond has been developed: single crystal CVD diamond which resolves many of the issues associated with poly-crystalline CVD material. The first tests of this material are also presented.

  16. New developments in CVD diamond for detector applications

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W. [HEPHY, Vienna (Austria); Berdermann, E. [GSI, Darmstadt (Germany); Bergonzo, P.; Brambilla, A. [LETI/DEIN/SPE/CEA Saclay (France); Boer, W. de [Universitaet Karlsruhe, Karlsruhe (Germany); Bogani, F. [LENS, Florence (Italy); Borchi, E.; Bruzzi, M. [University of Florence (Italy); Colledani, C.; Dulinski, W. [LEPSI, IN2P3/CNRS-ULP, Strasbourg (France); Conway, J.; Doroshenko, J. [Rutgers University, Piscataway (United States); D' Angelo, P.; Furetta, C. [INFN, Milano (Italy); Dabrowski, W. [UMM, Cracow (Poland); Delpierre, P.; Fallou, A. [CPPM, Marseille (France); Eijk, B. van [NIKHEF, Amsterdam (Netherlands); Fischer, P. [Universitaet Bonn, Bonn (Germany); Fizzotti, F. [University of Torino (Italy); Gan, K.K.; Ghodbane, N.; Grigoriev, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kaplon, J.; Kass, R.; Keil, M.; Knoepfle, K.T.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D.; Menichelli, D.; Meuser, S.; Mishina, M.; Moroni, L.; Noomen, J.; Oh, A.; Pernicka, M.; Perera, L.; Potenza, R.; Riester, J.L.; Roe, S.; Rudge, A.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Sutera, C.; Trischuk, W.; Tromson, D.; Tuve, C.; Vincenzo, B.; Weilhammer, P.; Wermes, N.; Wetstein, M.; Zeuner, W.; Zoeller, M.

    2004-07-01

    Chemical Vapor Deposition (CVD) diamond has been discussed extensively as an alternative sensor material for use very close to the interaction region of the LHC and other machines where extreme radiation conditions exist. During the last seven years the RD42 collaboration has developed diamond detectors and tested them with LHC electronics towards the end of creating a device usable by experiments. The most recent results of this work are presented. Recently, a new form of CVD diamond has been developed: single crystal CVD diamond which resolves many of the issues associated with poly-crystalline CVD material. The first tests of this material are also presented. (orig.)

  17. The development of diamond tracking detectors for the LHC

    CERN Document Server

    Adam, W; Bergonzo, P; de Boer, Wim; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, M; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Doroshenko, J; Dulinski, W; van Eijk, B; Fallou, A; Fischer, P; Fizzotti, F; Furetta, C; Gan, K K; Ghodbane, N; Grigoriev, E; Hallewell, G D; Han, S; Hartjes, F; Hrubec, Josef; Husson, D; Kagan, H; Kaplon, J; Karl, C; Kass, R; Keil, M; Knöpfle, K T; Koeth, T W; Krammer, M; Lo Giudice, A; Lü, R; MacLynne, L; Manfredotti, C; Marshall, R D; Meier, D; Menichelli, D; Meuser, S; Mishina, M; Moroni, L; Noomen, J; Oh, A; Perera, L; Pernegger, H; Pernicka, M; Polesello, P; Potenza, R; Riester, J L; Roe, S; Rudge, A; Sala, S; Sampietro, M; Schnetzer, S; Sciortino, S; Stelzer, H; Stone, R; Sutera, C; Trischuk, W; Tromson, D; Tuvé, C; Vincenzo, B; Weilhammer, P; Wermes, N; Wetstein, M; Zeuner, W; Zöller, M

    2003-01-01

    Chemical vapor deposition diamond has been discussed extensively as an alternate sensor material for use very close to the interaction region of the LHC where extreme radiation conditions exist. During the last few years diamond devices have been manufactured and tested with LHC electronics with the goal of creating a detector usable by all LHC experiment. Extensive progress on diamond quality, on the development of diamond trackers and on radiation hardness studies has been made. Transforming the technology to the LHC specific requirements is now underway. In this paper we present the recent progress achieved.

  18. The development of diamond tracking detectors for the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Boer, W. de; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Doroshenko, J.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fischer, P.; Fizzotti, F.; Furetta, C.; Gan, K.K.; Ghodbane, N.; Grigoriev, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H. E-mail: harris.kagan@cern.ch; Kaplon, J.; Karl, C.; Kass, R.; Keil, M.; Knoepfle, K.T.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Menichelli, D.; Meuser, S.; Mishina, M.; Moroni, L.; Noomen, J.; Oh, A.; Perera, L.; Pernegger, H.; Pernicka, M.; Polesello, P.; Potenza, R.; Riester, J.L.; Roe, S.; Rudge, A.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Sutera, C.; Trischuk, W.; Tromson, D.; Tuve, C.; Vincenzo, B.; Weilhammer, P.; Wermes, N.; Wetstein, M.; Zeuner, W.; Zoeller, M

    2003-11-21

    Chemical vapor deposition diamond has been discussed extensively as an alternate sensor material for use very close to the interaction region of the LHC where extreme radiation conditions exist. During the last few years diamond devices have been manufactured and tested with LHC electronics with the goal of creating a detector usable by all LHC experiment. Extensive progress on diamond quality, on the development of diamond trackers and on radiation hardness studies has been made. Transforming the technology to the LHC specific requirements is now underway. In this paper we present the recent progress achieved.

  19. New developments in CVD diamond for detector applications

    International Nuclear Information System (INIS)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Brambilla, A.; Boer, W. de; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Dulinski, W.; Conway, J.; Doroshenko, J.; D'Angelo, P.; Furetta, C.; Dabrowski, W.; Delpierre, P.; Fallou, A.; Eijk, B. van; Fischer, P.; Fizzotti, F.; Gan, K.K.; Ghodbane, N.; Grigoriev, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kaplon, J.; Kass, R.; Keil, M.; Knoepfle, K.T.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D.; Menichelli, D.; Meuser, S.; Mishina, M.; Moroni, L.; Noomen, J.; Oh, A.; Pernicka, M.; Perera, L.; Potenza, R.; Riester, J.L.; Roe, S.; Rudge, A.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Sutera, C.; Trischuk, W.; Tromson, D.; Tuve, C.; Vincenzo, B.; Weilhammer, P.; Wermes, N.; Wetstein, M.; Zeuner, W.; Zoeller, M.

    2004-01-01

    Chemical Vapor Deposition (CVD) diamond has been discussed extensively as an alternative sensor material for use very close to the interaction region of the LHC and other machines where extreme radiation conditions exist. During the last seven years the RD42 collaboration has developed diamond detectors and tested them with LHC electronics towards the end of creating a device usable by experiments. The most recent results of this work are presented. Recently, a new form of CVD diamond has been developed: single crystal CVD diamond which resolves many of the issues associated with poly-crystalline CVD material. The first tests of this material are also presented. (orig.)

  20. The development of diamond tracking detectors for the LHC

    Science.gov (United States)

    Adam, W.; Berdermann, E.; Bergonzo, P.; de Boer, W.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Doroshenko, J.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fischer, P.; Fizzotti, F.; Furetta, C.; Gan, K. K.; Ghodbane, N.; Grigoriev, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kaplon, J.; Karl, C.; Kass, R.; Keil, M.; Knöpfle, K. T.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; mac Lynne, L.; Manfredotti, C.; Marshall, R. D.; Meier, D.; Menichelli, D.; Meuser, S.; Mishina, M.; Moroni, L.; Noomen, J.; Oh, A.; Perera, L.; Pernegger, H.; Pernicka, M.; Polesello, P.; Potenza, R.; Riester, J. L.; Roe, S.; Rudge, A.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Sutera, C.; Trischuk, W.; Tromson, D.; Tuve, C.; Vincenzo, B.; Weilhammer, P.; Wermes, N.; Wetstein, M.; Zeuner, W.; Zoeller, M.; RD42 Collaboration

    2003-11-01

    Chemical vapor deposition diamond has been discussed extensively as an alternate sensor material for use very close to the interaction region of the LHC where extreme radiation conditions exist. During the last few years diamond devices have been manufactured and tested with LHC electronics with the goal of creating a detector usable by all LHC experiment. Extensive progress on diamond quality, on the development of diamond trackers and on radiation hardness studies has been made. Transforming the technology to the LHC specific requirements is now underway. In this paper we present the recent progress achieved.

  1. Stress analysis of CVD diamond window for ECH system

    International Nuclear Information System (INIS)

    Takahashi, Koji

    2001-03-01

    The stress analysis of a chemical vapor deposition (CVD) diamond window for Electron Cyclotron Heating and Current Drive (ECH/ECCD) system of fusion reactors is described. It was found that the real size diamond window (φ aper =70mm, t=2.25mm) withstood 14.5 atm. (1.45 MPa). The calculation results of the diamond window by ABAQUS code agree well with the results of the pressure test. The design parameters of the torus diamond window for a vacuum and a safety barrier were also obtained. (author)

  2. Novel diamond-coated tools for dental drilling applications.

    Science.gov (United States)

    Jackson, M J; Sein, H; Ahmed, W; Woodwards, R

    2007-01-01

    The application of diamond coatings on cemented tungsten carbide (WC-Co) tools has been the subject of much attention in recent years in order to improve cutting performance and tool life in orthodontic applications. WC-Co tools containing 6% Co metal and 94% WC substrate with an average grain size of 1 - 3 microm were used in this study. In order to improve the adhesion between diamond and WC substrates it is necessary to etch cobalt from the surface and prepare it for subsequent diamond growth. Alternatively, a titanium nitride (TiN) interlayer can be used prior to diamond deposition. Hot filament chemical vapour deposition (HFCVD) with a modified vertical filament arrangement has been employed for the deposition of diamond films to TiN and etched WC substrates. Diamond film quality and purity has been characterized using scanning electron microscopy (SEM) and micro Raman spectroscopy. The performances of diamond-coated WC-Co tools, uncoated WC-Co tools, and diamond embedded (sintered) tools have been compared by drilling a series of holes into various materials such as human tooth, borosilicate glass, and acrylic tooth materials. Flank wear has been used to assess the wear rates of the tools when machining biomedical materials such as those described above. It is shown that using an interlayer such as TiN prior to diamond deposition provides the best surface preparation for producing dental tools.

  3. Tailoring nanocrystalline diamond coated on titanium for osteoblast adhesion.

    Science.gov (United States)

    Pareta, Rajesh; Yang, Lei; Kothari, Abhishek; Sirinrath, Sirivisoot; Xiao, Xingcheng; Sheldon, Brian W; Webster, Thomas J

    2010-10-01

    Diamond coatings with superior chemical stability, antiwear, and cytocompatibility properties have been considered for lengthening the lifetime of metallic orthopedic implants for over a decade. In this study, an attempt to tailor the surface properties of diamond films on titanium to promote osteoblast (bone forming cell) adhesion was reported. The surface properties investigated here included the size of diamond surface features, topography, wettability, and surface chemistry, all of which were controlled during microwave plasma enhanced chemical-vapor-deposition (MPCVD) processes using CH4-Ar-H2 gas mixtures. The hardness and elastic modulus of the diamond films were also determined. H2 concentration in the plasma was altered to control the crystallinity, grain size, and topography of the diamond coatings, and specific plasma gases (O2 and NH3) were introduced to change the surface chemistry of the diamond coatings. To understand the impact of the altered surface properties on osteoblast responses, cell adhesion tests were performed on the various diamond-coated titanium. The results revealed that nanocrystalline diamond (grain sizes diamond and, thus, should be further studied for improving orthopedic applications. Copyright 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

  4. An electrical conductivity inspection methodology of polycrystalline diamond cutters

    Science.gov (United States)

    Bogdanov, G.; Wiggins, J.; Bertagnolli, K.; Ludwig, R.

    2012-05-01

    The polycrystalline diamond cutter (PDC) is widely used in oil and gas drilling operations. It is manufactured by sintering diamond powder onto a tungsten carbide substrate at 6 GPa and 1500 C. During sintering, molten cobalt from the substrate infiltrates the diamond table. The residual metal content correlates with cutter performance. We present an instrument that employs electrical impedance tomography capable of imaging the 3D metal content distribution in the diamond table. These images can be used to predict cutter performance as well as detect flaws.

  5. Effect of pretreatment and deposition parameters on diamond nucleation in CVD

    International Nuclear Information System (INIS)

    Nazim, E.; Izman, S.; Ourdjini, A.; Shaharoun, A.M.

    2007-01-01

    Chemical vapour deposition (CVD) of diamond films on cemented carbide (WC) has aroused great interest in recent years. The combination of toughness from the WC and the high hardness of diamond results in outstanding wear resistance. This will increase the lifetime and better technical performance of the components made of diamond coated carbide. One of the important steps in the growth of diamond film is the nucleation of diamond as its density strongly influences the diamond growth process, film quality and morphology. In this paper the various effects of surface pretreatment and diamond deposition conditions on the diamond nucleation density are reviewed. (author)

  6. Panel 2 - properties of diamond and diamond-like-carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.J.; Clausing, R.E. [Oak Ridge National Lab., TN (United States); Ajayi, O.O.; Liu, Y.Y.; Purohit, A. [Argonne National Lab., IL (United States); Bartelt, P.F. [Deere & Co., Moline, IL (United States); Baughman, R.H. [Allied Signal, Morristown, NJ (United States); Bhushan, B. [Ohio State Univ., Columbus (United States); Cooper, C.V. [United Technologies Research Center, East Hartford, CT (United States); Dugger, M.T. [Sandia National Laboratories, Albuquerque, NM (United States); Freedman, A. [Aerodyne Research, Inc., Billerica, MA (United States); Larsen-Basse, J. [National Science Foundation, Washington, DC (United States); McGuire, N.R. [Caterpillar, Peoria, IL (United States); Messier, R.F. [Pennsylvania State Univ., University Park (United States); Noble, G.L.; Ostrowki, M.H. [John Crane, Inc., Morton Grove, IL (United States); Sartwell, B.D. [Naval Research Lab., Washington, DC (United States); Wei, R. [Colorado State Univ., Fort Collins (United States)

    1993-01-01

    This panel attempted to identify and prioritize research and development needs in determining the physical, mechanical and chemical properties of diamond and diamond-like-carbon films (D/DLCF). Three specific goals were established. They were: (1) To identify problem areas which produce concern and require a better knowledge of D/DLCF properties. (2) To identify and prioritize key properties of D/DLCF to promote transportation applications. (3) To identify needs for improvement in properties-measurement methods. Each of these goals is addressed subsequently.

  7. 'Miniskirt' counter array at CDF II

    International Nuclear Information System (INIS)

    Artikov, A.; Artikov, A.

    2006-01-01

    Full text: Muon detection is fundamental for the most of the interesting analyses at CDF. At the course of Run II, the collaboration expects to collect hundreds of t t-bar decays yielding a muon as well as several million B-hadron events involving J/ψ → μ + μ - decays. Muon detection is also of fundamental importance in the study of W-boson properties and in the search for Higgs production associated with W or Z bosons. Considerable effort therefore went into extending the muon detector coverage for Run II, which started in March 2001. The CDF II muon detector system consists of multiple layers of drift chambers and scintillation counters, which span the pseudorapidity (|η|) range between 0 and 1.5. Detectors spanning different ranges have different geometries, and the muon scintillation counter system includes subsystems in the regions that have come to be known as the 'central' (0 pe for WLS fiber readout is smaller than for conventional readout, we can also expect an increase in the statistical contribution to the overall uncertainty. Our first concern, before adopting this solution, was therefore to ascertain that the mean timing resolution obtained under these conditions was adequate. The modifications, testing and installation of these counters within the CDF Upgrade Project are described in detail. The timing characteristics of MSX' counters are also investigated using cosmic muons. The measurements show that the time resolution does not exceed 2.2 ns. (author)

  8. Cerenkov counters at the Omega Facility

    CERN Multimedia

    1975-01-01

    P. Petroff on the left. Here one sees both the gas Cerenkov counters sitting in front of the magnet to select forward emitted particles. The smaller one, working at high pressure, sits nearest to the Omega magnet (see photo 7505073X), the other (see photo 7505071X) works at atmospheric pressure.

  9. A gridded air counter for measuring exoelectrons

    International Nuclear Information System (INIS)

    Nagase, Makoto; Chiba, Yoshiya; Kirihata, Humiaki.

    1980-01-01

    A gridded air counter with a quenching circuit is described, which serves to detect low-energy electrons such as thermionic electrons, photoelectrons and exoelectrons emitted into the atmospheric air. The air counter consists of a loop-shaped anode and two grids provided for quenching the gas discharge and for protecting the electron emitter from the positive ion bombardment. The quenching circuit with a high input sensitivity of 5 mV detects the initiation gas discharge caused by an incident electron and immediately supplies a rectangular wave pulse of 300 V in amplitude and of more than 3 msec in width to the quenching grid near the anode. Simultaneously, the voltage of the suppressor grid is brought down and kept at -30 V against the earthed sample for the same period of time. Performance of the gridded air counter was examined by use of photoelectrons emitted from an abraded aluminum plate. The quenching action was successfully accomplished in the anode voltage range from 3.65 to 3.95 kV. The photoelectrons emitted into the atmosphere could be counted stably by use of this counter. (author)

  10. Platelet counting using the Coulter electronic counter.

    Science.gov (United States)

    Eggleton, M J; Sharp, A A

    1963-03-01

    A method for counting platelets in dilutions of platelet-rich plasm using the Coulter electronic counter is described.(1) The results obtained show that such platelet counts are at least as accurate as the best methods of visual counting. The various technical difficulties encountered are discussed.

  11. Counter Trafficking System Development "Analysis Training Program"

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Dennis C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-12-01

    This document will detail the training curriculum for the Counter-Trafficking System Development (CTSD) Analysis Modules and Lesson Plans are derived from the United States Military, Department of Energy doctrine and Lawrence Livermore National Laboratory (LLNL), Global Security (GS) S Program.

  12. Micropipette as Coulter counter for submicron particles

    Science.gov (United States)

    Rudzevich, Yauheni; Ordonez, Tony; Evans, Grant; Chow, Lee

    2011-03-01

    Coulter counter based on micropipette has been around for several decades. Typical commercial Coulter counter has a pore size of 20 μ m, and is designed to detect micron-size blood cells. In recent years, there are a lot of interests in using nanometer pore size Coulter counter to detect single molecule and to sequence DNA. Here we describe a simple nanoparticle counter based on pulled micropipettes with a diameter of 50 -- 500 nm. Borosilicate micropipettes with an initial outer diameter of 1.00 mm and inner diameter of 0.5 mm are used. After pulling, the micropipettes are fire polished and ultrasound cleaned. Chlorinated Ag/AgCl electrodes and 0.1 M of KCl solution are used. The ionic currents are measured using an Axopatch 200B amplifier in the voltage-clamp mode. Several types and sizes of nanoparticles are measured, including plain silica and polystyrene nanospheres. The results will be discussed in terms of pH values of the solution and concentrations of the nanoparticles. Financial support from National Science Foundation (NSF-0901361) is acknowledged.

  13. Sealed drift tube cosmic ray veto counters

    International Nuclear Information System (INIS)

    Rios, R.; Tatar, E.; Bacon, J.D.; Bowles, T.J.; Hill, R.; Green, J.A.; Hogan, G.E.; Ito, T.M.; Makela, M.; Morris, C.L.; Mortenson, R.; Pasukanics, F.E.; Ramsey, J.; Saunders, A.; Seestrom, S.J.; Sondheim, W.E.; Teasdale, W.; Saltus, M.; Back, H.O.; Cottrell, C.R.

    2011-01-01

    We describe a simple drift tube counter that has been used as a cosmic ray veto for the UCNA experiment, a first-ever measurement of the neutron beta-asymmetry using ultra-cold neutrons. These detectors provide an inexpensive alternative to more conventional scintillation detectors for large area cosmic ray anticoincidence detectors.

  14. COUNTER-ROTATION IN RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    Energy Technology Data Exchange (ETDEWEB)

    Cayatte, V.; Sauty, C. [Laboratoire Univers et Théories, Observatoire de Paris, UMR 8102 du CNRS, Université Paris Diderot, F-92190 Meudon (France); Vlahakis, N.; Tsinganos, K. [Department of Astrophysics, Astronomy and Mechanics, Faculty of Physics, University of Athens, 15784 Zografos, Athens (Greece); Matsakos, T. [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States); Lima, J. J. G., E-mail: veronique.cayatte@obspm.fr [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

    2014-06-10

    Young stellar object observations suggest that some jets rotate in the opposite direction with respect to their disk. In a recent study, Sauty et al. showed that this does not contradict the magnetocentrifugal mechanism that is believed to launch such outflows. Motion signatures that are transverse to the jet axis, in two opposite directions, have recently been measured in M87. One possible interpretation of this motion is that of counter-rotating knots. Here, we extend our previous analytical derivation of counter-rotation to relativistic jets, demonstrating that counter-rotation can indeed take place under rather general conditions. We show that both the magnetic field and a non-negligible enthalpy are necessary at the origin of counter-rotating outflows, and that the effect is associated with a transfer of energy flux from the matter to the electromagnetic field. This can be realized in three cases: if a decreasing enthalpy causes an increase of the Poynting flux, if the flow decelerates, or if strong gradients of the magnetic field are present. An illustration of the involved mechanism is given by an example of a relativistic magnetohydrodynamic jet simulation.

  15. Townsend coefficients of gases in avalanche counters

    International Nuclear Information System (INIS)

    Brunner, G.

    1978-01-01

    Though much work has been done by many authors in the last few years in the development and application of avalanche counters for ion radiation, it is based upon values of the Townsend coefficients as the essential gas parameter, which were determined many years ago for much lower reduced field strengths F/p than prevail in such counters. Therefore absolute determinations of α in vapours of methyl alcohol, cyclohexane, acetone, and n-heptene were performed under original conditions of avalanche counters. The values obtained do not differ by more than 30%-50% from the former values indeed, extrapolated over F/p for the first three mentioned substances, but the amounts of A and B in the usual representation α/p=A exp(-B(F/p)) are much greater for the stronger reduced fields. This is of importance for such counter properties as the dependence of pulse heights on pressure, voltage, electrode distance etc., which are governed by other combinations of A and B than α/p itself. A comparison of results for different ionic radiations shows a marked influence of the primary ionization density along the particle tracks which is hard to explain. (Auth.)

  16. Can counter-stereotypes boost flexible thinking?

    NARCIS (Netherlands)

    Goclowska, M.A.; Crisp, R.J.; Labuschagne, K.

    2013-01-01

    To reduce prejudice psychologists design interventions requiring people to think of counter-stereotypes (i.e., people who defy stereotypic expectations—a strong woman, a Black President). Grounded in the idea that stereotypes constrain the ability to think flexibly, we propose that thinking of

  17. Calibration of proportional counters in microdosimetry

    International Nuclear Information System (INIS)

    Varma, M.N.

    1982-01-01

    Many microdosimetric spectra for low LET as well as high LET radiations are measured using commercially available (similar to EG and G) Rossi proportional counters. This paper discusses the corrections to be applied to data when calibration of the counter is made using one type of radiation, and then the counter is used in a different radiation field. The principal correction factor is due to differences in W-value of the radiation used for calibration and the radiation for which microdosimetric measurements are made. Both propane and methane base tissue-equivalent (TE) gases are used in these counters. When calibrating the detectors, it is important to use the correct stopping power value for that gas. Deviations in y-bar/sub F/ and y-bar/sub D/ are calculated for 60 Co using different extrapolation procedures from 0.15 keV/μm to zero event size. These deviations can be as large as 30%. Advantages of reporting microdosimetric parameters such as y-bar/sub F/ and y-bar/sub D/ above a certain minimum cut-off are discussed

  18. E143 experiment. Shower counter calibration

    International Nuclear Information System (INIS)

    Fonvieille, H.; Grenier, P.

    1994-01-01

    The calibration procedure for the shower counters used in the E143 experiment is described. It has been developed during january 1994 in view of being used for the quick analysis. The method is explained and the results obtained on a given run are presented. (author)

  19. A wear simulation study of nanostructured CVD diamond-on-diamond articulation involving concave/convex mating surfaces

    Science.gov (United States)

    Baker, Paul A.; Thompson, Raymond G.; Catledge, Shane A.

    2015-01-01

    Using microwave-plasma Chemical Vapor Deposition (CVD), a 3-micron thick nanostructured-diamond (NSD) layer was deposited onto polished, convex and concave components that were machined from Ti-6Al-4V alloy. These components had the same radius of curvature, 25.4mm. Wear testing of the surfaces was performed by rotating articulation of the diamond-deposited surfaces (diamond-on-diamond) with a load of 225N for a total of 5 million cycles in bovine serum resulting in polishing of the diamond surface and formation of very shallow, linear wear grooves of less than 50nm depth. The two diamond surfaces remained adhered to the components and polished each other to an average surface roughness that was reduced by as much as a factor of 80 for the most polished region located at the center of the condyle. Imaging of the surfaces showed that the initial wearing-in phase of diamond was only beginning at the end of the 5 million cycles. Atomic force microscopy, scanning electron microscopy, Raman spectroscopy, and surface profilometry were used to characterize the surfaces and verify that the diamond remained intact and uniform over the surface, thereby protecting the underlying metal. These wear simulation results show that diamond deposition on Ti alloy has potential application for joint replacement devices with improved longevity over existing devices made of cobalt chrome and ultra-high molecular weight polyethylene (UHMWPE). PMID:26989457

  20. UV detectors based on epitaxial diamond films grown on single-crystal diamond substrates by vapor-phase synthesis

    International Nuclear Information System (INIS)

    Sharonov, G.V.; Petrov, S.A.; Bol'shakov, A.P.; Ral'chenko, V.G.; Kazyuchits, N.M.

    2010-01-01

    The prospects for use of CVD-technology for epitaxial growth of single-crystal diamond films of instrumental quality in UHF plasma for the production of optoelectronic devices are discussed. A technology for processing diamond single crystals that provides a perfect surface crystal structure with roughness less than 0,5 nm was developed. It was demonstrated that selective UV detectors based on synthetic single-crystal diamond substrates coated with single-crystal films can be produced. A criterion for selecting clean and structurally perfect single crystals of synthetic diamond was developed for the epitaxial growth technology. (authors)

  1. Israel's Counter-Terrorism Strategy and its Effectiveness

    National Research Council Canada - National Science Library

    Smith, Jerry D

    2005-01-01

    This thesis analyzes Israeli counter-terrorism strategy and its effectiveness. Because of ongoing suicide attacks from Palestinian and other terrorist organizations, Israel will continue to have an aggressive counter-terrorism strategy...

  2. 21 CFR 866.2180 - Manual colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony counter. (a) Identification. A manual colony counter is a device intended for medical purposes that consists...

  3. A fast photo-counter with multi-level buffers

    International Nuclear Information System (INIS)

    Peng Hu; Zhou Peiling; Yao Kun; Guo Guangcan

    1992-01-01

    Digital Photon Correlator (DPC) is composed of a Photo-counter and a data processing unit. The performance of Photo-counter in data acquisition system has a direct influence on data processing. The Photo-counter with fast carry designed here has multi-level buffers. Photon pulses can be correctly and dynamically recorded by the Photo-counter and processed by a single chip computer

  4. Rich man's salt: the diamonds in the soup

    Science.gov (United States)

    Ott, Ulrich

    Diamond nominally constitutes the most abundant of the presolar phases identified in primitive meteorites so far. An overview is given of known properties including isotopic abundances of trace elements that point to a supernova connection for at least part of the diamond grains. Scenarios for nucleosynthetic production of these trace elements and their introduction into the nanodiamonds are discussed as well as their observability.

  5. Microwave plasma deposition of diamond like carbon coatings

    Indian Academy of Sciences (India)

    Abstract. The promising applications of the microwave plasmas have been appearing in the fields of chemical processes and semiconductor manufacturing. Applications include surface deposition of all types including diamond/diamond like carbon (DLC) coatings, etching of semiconductors, promotion of organic reactions, ...

  6. Fabrication of Diamond Based Sensors for Use in Extreme Environments

    Directory of Open Access Journals (Sweden)

    Gopi K. Samudrala

    2015-04-01

    Full Text Available Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This method can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. We demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.

  7. Vector magnetic field microscopy using nitrogen vacancy centers in diamond

    NARCIS (Netherlands)

    Maertz, B.J.; Wijnheijmer, A.P.; Fuchs, G.D.; Nowakowski, M.E.; Awschalom, D.D.

    2010-01-01

    The localized spin triplet ground state of a nitrogen vacancy (NV) center in diamond can be used in atomic-scale detection of local magnetic fields. Here we present a technique using ensembles of these defects in diamond to image fields around magnetic structures. We extract the local magnetic field

  8. Book Review: Stones of Contention: A History of Africa's Diamonds ...

    African Journals Online (AJOL)

    or Register. DOWNLOAD FULL TEXT Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. Book Review: Stones of Contention: A History of Africa's Diamonds. H Smith. Abstract. Stones of Contention: A History of Africa's Diamonds. Author: Todd Cleveland. Ohio University Press: Athens OH, 2014. 225pp ...

  9. Functionalized diamond nanopowder for phosphopeptides enrichment from complex biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Dilshad [Division of Analytical Chemistry, Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60800 (Pakistan); Najam-ul-Haq, Muhammad, E-mail: najamulhaq@bzu.edu.pk [Division of Analytical Chemistry, Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60800 (Pakistan); Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 80-82, A-6020 Innsbruck (Austria); Jabeen, Fahmida; Ashiq, Muhammad N.; Athar, Muhammad [Division of Analytical Chemistry, Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60800 (Pakistan); Rainer, Matthias; Huck, Christian W.; Bonn, Guenther K. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 80-82, A-6020 Innsbruck (Austria)

    2013-05-02

    Graphical abstract: -- Highlights: •Derivatization of diamond nanopowder as IMAC and RP. •Characterization with SEM, EDX and FT-IR. •Phosphopeptide enrichment from standard as well as real samples. •Desalting and human serum profiling with reproducible results. •MALDI-MS analysis with database identification. -- Abstract: Diamond is known for its high affinity and biocompatibility towards biomolecules and is used exclusively in separation sciences and life science research. In present study, diamond nanopowder is derivatized as Immobilized Metal Ion Affinity Chromatographic (IMAC) material for the phosphopeptides enrichment and as Reversed Phase (C-18) media for the desalting of complex mixtures and human serum profiling through MALDI-TOF-MS. Functionalized diamond nanopowder is characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. Diamond-IMAC is applied to the standard protein (β-casein), spiked human serum, egg yolk and non-fat milk for the phosphopeptides enrichment. Results show the selectivity of synthesized IMAC-diamond immobilized with Fe{sup 3+} and La{sup 3+} ions. To comprehend the elaborated use, diamond-IMAC is also applied to the serum samples from gall bladder carcinoma for the potential biomarkers. Database search is carried out by the Mascot program ( (www.matrixscience.com)) for the assignment of phosphorylation sites. Diamond nanopowder is thus a separation media with multifunctional use and can be applied to cancer protein profiling for the diagnosis and biomarker identification.

  10. Micro-strip sensors based on CVD diamond

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D. E-mail: dirk.meier@cern.ch; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M

    2000-10-11

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

  11. Micro-strip sensors based on CVD Diamond

    CERN Document Server

    Adam, W; Bergonzo, P; Bertuccio, G; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Hallewell, G D; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Koeth, T W; Krammer, Manfred; Lo Giudice, A; Lü, R; MacLynne, L; Manfredotti, C; Meier, D; Mishina, M; Moroni, L; Oh, A; Pan, L S; Pernicka, Manfred; Peitz, A; Perera, L P; Pirollo, S; Procario, M; Riester, J L; Roe, S; Rousseau, L; Rudge, A; Russ, J; Sala, S; Sampietro, M; Schnetzer, S R; Sciortino, S; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R J; Trischuk, W; Tromson, D; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Wetstein, M; White, C; Zeuner, W; Zoeller, M M

    2000-01-01

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

  12. Micro-strip sensors based on CVD diamond

    International Nuclear Information System (INIS)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M.

    2000-01-01

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation

  13. Micro-strip sensors based on CVD diamond

    Science.gov (United States)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K. K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; mac Lynne, L.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L. S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J. L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R. J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M.; RD42 Collaboration

    2000-10-01

    In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

  14. NEW HIGH STRENGTH AND FASTER DRILLING TSP DIAMOND CUTTERS

    Energy Technology Data Exchange (ETDEWEB)

    Robert Radtke

    2006-01-31

    The manufacture of thermally stable diamond (TSP) cutters for drill bits used in petroleum drilling requires the brazing of two dissimilar materials--TSP diamond and tungsten carbide. The ENDURUS{trademark} thermally stable diamond cutter developed by Technology International, Inc. exhibits (1) high attachment (shear) strength, exceeding 345 MPa (50,000 psi), (2) TSP diamond impact strength increased by 36%, (3) prevents TSP fracture when drilling hard rock, and (4) maintains a sharp edge when drilling hard and abrasive rock. A novel microwave brazing (MWB) method for joining dissimilar materials has been developed. A conventional braze filler metal is combined with microwave heating which minimizes thermal residual stress between materials with dissimilar coefficients of thermal expansion. The process results in preferential heating of the lower thermal expansion diamond material, thus providing the ability to match the thermal expansion of the dissimilar material pair. Methods for brazing with both conventional and exothermic braze filler metals have been developed. Finite element modeling (FEM) assisted in the fabrication of TSP cutters controllable thermal residual stress and high shear attachment strength. Further, a unique cutter design for absorbing shock, the densification of otherwise porous TSP diamond for increased mechanical strength, and diamond ion implantation for increased diamond fracture resistance resulted in successful drill bit tests.

  15. Investigation of laser ablation of CVD diamond film

    Science.gov (United States)

    Chao, Choung-Lii; Chou, W. C.; Ma, Kung-Jen; Chen, Ta-Tung; Liu, Y. M.; Kuo, Y. S.; Chen, Ying-Tung

    2005-04-01

    Diamond, having many advanced physical and mechanical properties, is one of the most important materials used in the mechanical, telecommunication and optoelectronic industry. However, high hardness value and extreme brittleness have made diamond extremely difficult to be machined by conventional mechanical grinding and polishing. In the present study, the microwave CVD method was employed to produce epitaxial diamond films on silicon single crystal. Laser ablation experiments were then conducted on the obtained diamond films. The underlying material removal mechanisms, microstructure of the machined surface and related machining conditions were also investigated. It was found that during the laser ablation, peaks of the diamond grains were removed mainly by the photo-thermal effects introduced by excimer laser. The diamond structures of the protruded diamond grains were transformed by the laser photonic energy into graphite, amorphous diamond and amorphous carbon which were removed by the subsequent laser shots. As the protruding peaks gradually removed from the surface the removal rate decreased. Surface roughness (Ra) was improved from above 1μm to around 0.1μm in few minutes time in this study. However, a scanning technique would be required if a large area was to be polished by laser and, as a consequence, it could be very time consuming.

  16. 76 FR 48047 - Airworthiness Directives; Diamond Aircraft Industries Powered Sailplanes

    Science.gov (United States)

    2011-08-08

    ... 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this... Service Information Diamond Aircraft Industries GmbH has issued Service Bulletin No. MSB 36-105/1, dated...-105, dated April 21, 2011, as specified in Diamond Aircraft Industries GmbH Service Bulletin No. MSB...

  17. 78 FR 57104 - Airworthiness Directives; Diamond Aircraft Industries Airplanes

    Science.gov (United States)

    2013-09-17

    ... p.m., Monday through Friday, except Federal holidays. For service information identified in this... AD docket. Relevant Service Information Diamond Aircraft Industries GmbH has issued Mandatory Service... service information related to this AD, contact Diamond Aircraft Industries GmbH, N.A. Otto-Str.5, A-2700...

  18. Hard assets : The return on rare diamonds and gems

    NARCIS (Netherlands)

    Renneboog, L.D.R.; Spaenjers, C.

    2012-01-01

    This note examines the investment performance of diamonds and other gems (sapphires, rubies, and emeralds) over the period 1999–2010, using a novel data set of auction transactions. Over our time frame, the annualized real USD returns for white and colored diamonds equaled 6.4% and 2.9%,

  19. Hard Assets : The Returns on Rare Diamonds and Gems

    NARCIS (Netherlands)

    Renneboog, L.D.R.; Spaenjers, C.

    2011-01-01

    This paper examines the investment performance of diamonds and other gems (sapphires, rubies, and emeralds) over the period 1999-2010, using a novel data set of auction transactions. Between 1999 and 2010, the annualized real USD returns for white and colored diamonds equaled 6.4% and 2.9%,

  20. Fractional surface termination of diamond by electrochemical oxidation.

    Science.gov (United States)

    Hoffmann, René; Obloh, Harald; Tokuda, Norio; Yang, Nianjun; Nebel, Christoph E

    2012-01-10

    The crystalline form of sp(3)-hybridized carbon, diamond, offers various electrolyte-stable surface terminations. The H-termination-selective attachment of nitrophenyl diazonium, imaged by AFM, shows that electrochemical oxidation can control the fractional hydrogen/oxygen surface termination of diamond on the nanometer scale. This is of particular interest for all applications relying on interfacial electrochemistry, especially for biointerfaces.

  1. Diamond thin films: giving biomedical applications a new shine.

    Science.gov (United States)

    Nistor, P A; May, P W

    2017-09-01

    Progress made in the last two decades in chemical vapour deposition technology has enabled the production of inexpensive, high-quality coatings made from diamond to become a scientific and commercial reality. Two properties of diamond make it a highly desirable candidate material for biomedical applications: first, it is bioinert, meaning that there is minimal immune response when diamond is implanted into the body, and second, its electrical conductivity can be altered in a controlled manner, from insulating to near-metallic. In vitro, diamond can be used as a substrate upon which a range of biological cells can be cultured. In vivo , diamond thin films have been proposed as coatings for implants and prostheses. Here, we review a large body of data regarding the use of diamond substrates for in vitro cell culture. We also detail more recent work exploring diamond-coated implants with the main targets being bone and neural tissue. We conclude that diamond emerges as one of the major new biomaterials of the twenty-first century that could shape the way medical treatment will be performed, especially when invasive procedures are required. © 2017 The Authors.

  2. Hard assets : The return of rare diamonds and gems

    NARCIS (Netherlands)

    Renneboog, Luc; Spaenjers, Christophe; Grynberg, Roman; Mbayi, Letsema

    This note examines the investment performance of diamonds and other gems (sapphires, rubies, and emeralds) over the period 1999–2010, using a novel data set of auction transactions. Over our time frame, the annualized real USD returns for white and colored diamonds equaled 6.4% and 2.9%,

  3. Diamond films deposited by oxygen-enhanced linear plasma chemistry

    Czech Academy of Sciences Publication Activity Database

    Kromka, Alexander; Babchenko, Oleg; Ižák, Tibor; Varga, Marián; Davydova, Marina; Krátká, Marie; Rezek, Bohuslav

    2013-01-01

    Roč. 5, č. 6 (2013), s. 509-514 ISSN 2164-6627 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA ČR GAP108/12/0996 Institutional support: RVO:68378271 Keywords : diamond films * process gas chemistry * pulsed microwave plasma * surface conductivity of diamond Subject RIV: BM - Solid Matter Physics ; Magnetism

  4. First result on biased CMOS MAPs-on-diamond devices

    Energy Technology Data Exchange (ETDEWEB)

    Kanxheri, K., E-mail: keida.kanxheri@pg.infn.it [Università degli Studi di Perugia, Perugia (Italy); INFN Perugia, Perugia (Italy); Citroni, M.; Fanetti, S. [LENS Firenze, Florence (Italy); Lagomarsino, S. [Università degli Studi di Firenze, Florence (Italy); INFN Firenze, Pisa (Italy); Morozzi, A. [Università degli Studi di Perugia, Perugia (Italy); INFN Perugia, Perugia (Italy); Parrini, G. [Università degli Studi di Firenze, Florence (Italy); Passeri, D. [Università degli Studi di Perugia, Perugia (Italy); INFN Perugia, Perugia (Italy); Sciortino, S. [Università degli Studi di Firenze, Florence (Italy); INFN Firenze, Pisa (Italy); Servoli, L. [INFN Perugia, Perugia (Italy)

    2015-10-01

    Recently a new type of device, the MAPS-on-diamond, obtained bonding a thinned to 25 μm CMOS Monolithic Active Pixel Sensor to a standard 500 μm pCVD diamond substrate, has been proposed and fabricated, allowing a highly segmented readout (10×10 μm pixel size) of the signal produced in the diamond substrate. The bonding between the two materials has been obtained using a new laser technique to deliver the needed energy at the interface. A biasing scheme has been adopted to polarize the diamond substrate to allow the charge transport inside the diamond without disrupting the functionalities of the CMOS Monolithic Active Pixel Sensor. The main concept of this class of devices is the capability of the charges generated in the diamond by ionizing radiation to cross the silicon–diamond interface and to be collected by the MAPS photodiodes. In this work we demonstrate that such passage occurs and measure its overall efficiency. This study has been carried out first calibrating the CMOS MAPS with monochromatic X-rays, and then testing the device with charged particles (electrons) either with and without biasing the diamond substrate, to compare the amount of signal collected.

  5. Brilliant camouflage : photonic crystals in the diamond weevil, Entimus imperialis

    NARCIS (Netherlands)

    Wilts, Bodo D.; Michielsen, Kristel; Kuipers, Jeroen; Raedt, Hans De; Stavenga, Doekele G.

    2012-01-01

    The neotropical diamond weevil, Entimus imperialis, is marked by rows of brilliant spots on the overall black elytra. The spots are concave pits with intricate patterns of structural-coloured scales, consisting of large domains of three-dimensional photonic crystals that have a diamond-type

  6. Spectral analysis of the structure of ultradispersed diamonds

    Science.gov (United States)

    Uglov, V. V.; Shimanski, V. I.; Rusalsky, D. P.; Samtsov, M. P.

    2008-07-01

    The structure of ultradispersed diamonds (UDD) is studied by spectral methods. The presence of diamond crystal phase in the UDD is found based on x-ray analysis and Raman spectra. The Raman spectra also show sp2-and sp3-hybridized carbon. Analysis of IR absorption spectra suggests that the composition of functional groups present in the particles changes during the treatment.

  7. Efficiency calibration of solid track spark auto counter

    International Nuclear Information System (INIS)

    Wang Mei; Wen Zhongwei; Lin Jufang; Liu Rong; Jiang Li; Lu Xinxin; Zhu Tonghua

    2008-01-01

    The factors influencing detection efficiency of solid track spark auto counter were analyzed, and the best etch condition and parameters of charge were also reconfirmed. With small plate fission ionization chamber, the efficiency of solid track spark auto counter at various experiment assemblies was re-calibrated. The efficiency of solid track spark auto counter at various experimental conditions was obtained. (authors)

  8. Counter-responses as organizers in adolescent analysis and therapy.

    Science.gov (United States)

    Richmond, M Barrie

    2004-01-01

    The author introduces Counter-response as a phenomological term to replace theory-burdened terms like counter-transference, counter-identification, and counter-resistance. He discusses the analyst's use of self (drawing on the comparison with Winnicott's use of the object) in processing the expectable destabilizing counter-reactions that occur in working therapeutically with disturbed adolescents and their parents. Further; he discusses the counter-reaction to the patient's narrative, acting-out, and how re-enactments can serve as an organizer for understanding the patient's inner life when the analyst formulates his/her counter-response. Emphasis is placed on the therapist forming his or her own narrative with the adolescent that takes into account the evoked counter-reaction. For this purpose, the author recommends the use of a combined counter-response and metaphor-orienting perspective to acknowledge and work with the denial, illusions, reversal of perspective, and catastrophic anxieties experienced with these adolescents. The counter-response perspective permits the emergence of the disturbed adolescent's novel narrative; however, since these experiences can be destabilizing or disruptive, the author also recommends the use of a personal metaphor to anticipate the reluctance to examining, processing, and formulating the analyst's dysphoric counter-reaction. With the use of the counter-response, the analyst's therapeutic ideal is to achieve a more optimal balance between using accepted narrative theories and exploring novel enactment experiences. His swimming metaphor stratagem is designed to keep the analyst in these difficult encounters.

  9. Generalization of the development of liquid-sparkling counter

    International Nuclear Information System (INIS)

    Bian Zhengzhu; Zhang Jue; Zhang Jinwei

    2006-01-01

    This paper includes five parts. It not only reviews the development history of liquid-sparkling counter but refers that the appearance of coincident circuit is its milestone. The paper summarizes the resembled hard ware and soft ware and soft ware of liquid-sparkling counter of indoor and overseas, and prospects the development of liquid-sparkling counter in our country. (authors)

  10. Computational assignment of redox states to Coulomb blockade diamonds.

    Science.gov (United States)

    Olsen, Stine T; Arcisauskaite, Vaida; Hansen, Thorsten; Kongsted, Jacob; Mikkelsen, Kurt V

    2014-09-07

    With the advent of molecular transistors, electrochemistry can now be studied at the single-molecule level. Experimentally, the redox chemistry of the molecule manifests itself as features in the observed Coulomb blockade diamonds. We present a simple theoretical method for explicit construction of the Coulomb blockade diamonds of a molecule. A combined quantum mechanical/molecular mechanical method is invoked to calculate redox energies and polarizabilities of the molecules, including the screening effect of the metal leads. This direct approach circumvents the need for explicit modelling of the gate electrode. From the calculated parameters the Coulomb blockade diamonds are constructed using simple theory. We offer a theoretical tool for assignment of Coulomb blockade diamonds to specific redox states in particular, and a study of chemical details in the diamonds in general. With the ongoing experimental developments in molecular transistor experiments, our tool could find use in molecular electronics, electrochemistry, and electrocatalysis.

  11. Comparison of natural and synthetic diamond X-ray detectors

    International Nuclear Information System (INIS)

    Lansley, S. P.; Betzel, G.T.; Meyer, J.; Metcalf, P.; Reinisch, L.

    2010-01-01

    Full text: Diamond detectors are particularly well suited for dosimetry applications in radiotherapy for reasons including near-tissue equivalence and high-spatial resolu tion resulting from small sensitive volumes. However, these detectors have not become commonplace due to high cost and poor availability arising from the need for high quality diamond. We have fabricated relatively cheap detectors from commercially-available synthetic diamond fabricated using chemical vapour deposition. Here, we present a comparison of one of these detectors with the only commercially-available diamond-based detector (which uses a natural diamond crystal). Parameters such as the energy dependence and linearity of charge with dose were investigated at orthovoltage energies (50-250 kY), and dose-rate dependence of charge at linear accelerator energy (6 MY). The energy dependence of a synthetic diamond detector was similar to that of the natural diamond detector, albeit with slightly less variation across the energy range. Both detectors displayed a linear response S. P. Lansley () . G. T. Betzel . J. Meyer Department of Physics and Astronomy, University of Canterbury, Christchurch, New Zealand e-mail: stuart.lansley canterbury.ac.nz S. P. Lansley The Macdiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, Christchurch, New Zealand P. Metcalfe Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia L. Reinisch Department of Physical and Earth Sciences, Jacksonville State University, Jacksonville, AL, USA with dose (at 100 kY) over the limited dose range used. The sensitivity of the synthetic diamond detector was 302 nC/Gy, compared to 294 nC/Gy measured for the natural diamond detector; however, this was obtained with a bias of 246.50 Y compared to a bias of 61.75 Y used for the natural diamond detector. The natural diamond detector exhibited a greater dependency on dose-rate than the syn thetic diamond detector. Overall

  12. Chemical vapour deposition synthetic diamond: materials, technology and applications

    International Nuclear Information System (INIS)

    Balmer, R S; Brandon, J R; Clewes, S L; Dhillon, H K; Dodson, J M; Friel, I; Inglis, P N; Madgwick, T D; Markham, M L; Mollart, T P; Perkins, N; Scarsbrook, G A; Twitchen, D J; Whitehead, A J; Wilman, J J; Woollard, S M

    2009-01-01

    Substantial developments have been achieved in the synthesis of chemical vapour deposition (CVD) diamond in recent years, providing engineers and designers with access to a large range of new diamond materials. CVD diamond has a number of outstanding material properties that can enable exceptional performance in applications as diverse as medical diagnostics, water treatment, radiation detection, high power electronics, consumer audio, magnetometry and novel lasers. Often the material is synthesized in planar form; however, non-planar geometries are also possible and enable a number of key applications. This paper reviews the material properties and characteristics of single crystal and polycrystalline CVD diamond, and how these can be utilized, focusing particularly on optics, electronics and electrochemistry. It also summarizes how CVD diamond can be tailored for specific applications, on the basis of the ability to synthesize a consistent and engineered high performance product.

  13. Diamond Windows for High Powered Microwave Transmission. Final Report

    International Nuclear Information System (INIS)

    Gat, R.

    2011-01-01

    This phase II SBIR developed technology for manufacturing diamond windows for use in high energy density photon transmission e.g. microwave or laser light photons. Microwave sources used in fusion research require microwave extraction windows with high thermal conductivity, low microwave absorption, and low resistance to thermal cracking. Newly developed, man made diamond windows have all three of these properties, but these windows are prohibitively expensive. This limits the natural progress of these important technologies to higher powers and slows the development of additional applications. This project developed a lower cost process for manufacturing diamond windows using microwave plasma. Diamond windows were deposited. A grinding process was used to provide optical smoothness for 2 cm diameter diamond windows that met the parallelism specifications for fusion beam windows. The microwave transmission performance (loss tangent) of one of the windows was measured at 95GHz to be less than 10-4, meeting specifications for utilization in the ITER tokamak.

  14. Growth, characterization and device development in monocrystalline diamond films

    Science.gov (United States)

    Davis, R. F.; Glass, J. T.; Nemanich, R. J.; Bozeman, S. P.; Sowers, A. T.

    1995-06-01

    Experimental and theoretical studies concerned with interface interactions of diamond with Si, Ni, and Ni3Si substrates have been conducted. Oriented diamond films deposited on (100) Si were characterized by polar Raman, polar x-ray diffraction (XRD), and cross-sectional high resolution transmission electron microscopy (HRTEM). These sutides showed that the diamond(100)/Si(100) interface adopted the 3:2-match arrangement rather than a 45 deg rotation. Extended Hueckel tight-binding (EHTB) electronic structure calculations for a model system revealed that the interface interaction favors the 3:2-match arrangement. Growth on polycrystalline Ni3Si resulted in oriented diamond particles; under the same growth conditions, graphite was formed on the nickel substrate. Our EHTB electronic structure calculations showed that the (111) and (100) surfaces of Ni3Si have a strong preference for diamond nucleation over graphite nucleation, but this was not the case for the (111) and (100) surfaces of Ni.

  15. Electroluminescence Spectrum Shift with Switching Behaviour of Diamond Thin Films

    Institute of Scientific and Technical Information of China (English)

    王小平; 王丽军; 张启仁; 姚宁; 张兵临

    2003-01-01

    We report a special phenomenon on switching behaviour and the electroluminescence (EL) spectrum shift of doped diamond thin films. Nitrogen and cerium doped diamond thin films were deposited on a silicon substrate by microwave plasma-assisted chemical vapour deposition system and other special techniques. An EL device with a three-layer structure of nitrogen doped diamond/cerium doped diamond/SiO2 thin films was made. The EL device was driven by a direct-current power supply. Its EL character has been investigated, and a switching behaviour was observed. The EL light emission colour of diamond films changes from yellow (590nm) to blue (454 nm) while the switching behaviour appears.

  16. Surface smoothening effects on growth of diamond films

    Science.gov (United States)

    Reshi, Bilal Ahmad; Kumar, Shyam; Kartha, Moses J.; Varma, Raghava

    2018-04-01

    We have carried out a detailed study of the growth dynamics of the diamond film during initial time on diamond substrates. The diamond films are deposited using Microwave Plasma Chemical Vapor Deposition (MPCVD) method for different times. Surface morphology and its correlation with the number of hours of growth of thin films was invested using atomic force microscopy (AFM). Diamond films have smooth interface with average roughness of 48.6873nm. The initial growth dynamics of the thin film is investigated. Interestingly, it is found that there is a decrease in the surface roughness of the film. Thus a smoothening effect is observed in the grown films. The film enters into the growth regime in the later times. Our results also find application in building diamond detector.

  17. Direct conversion of graphite into diamond through electronic excited states

    CERN Document Server

    Nakayama, H

    2003-01-01

    An ab initio total energy calculation has been performed for electronic excited states in diamond and rhombohedral graphite by the full-potential linearized augmented plane wave method within the framework of the local density approximation (LDA). First, calculations for the core-excited state in diamond have been performed to show that the ab initio calculations based on the LDA describe the wavefunctions in the electronic excited states as well as in the ground state quite well. Fairly good coincidence with both experimental data and theoretical prediction has been obtained for the lattice relaxation of the core exciton state. The results of the core exciton state are compared with nitrogen-doped diamond. Next, the structural stability of rhombohedral graphite has been investigated to examine the possibility of the transition into the diamond structure through electronic excited states. While maintaining the rhombohedral symmetry, rhombohedral graphite can be spontaneously transformed to cubic diamond. Tota...

  18. Crystal growth of CVD diamond and some of its peculiarities

    CERN Document Server

    Piekarczyk, W

    1999-01-01

    Experiments demonstrate that CVD diamond can form in gas environments that are carbon undersaturated with respect to diamond. This fact is, among others, the most serious violation of principles of chemical thermodynamics. In this $9 paper it is shown that none of the principles is broken when CVD diamond formation is considered not a physical process consisting in growth of crystals but a chemical process consisting in accretion of macro-molecules of polycyclic $9 saturated hydrocarbons belonging to the family of organic compounds the smallest representatives of which are adamantane, diamantane, triamantane and so forth. Since the polymantane macro-molecules are in every respect identical with $9 diamond single crystals with hydrogen-terminated surfaces, the accretion of polymantane macro- molecules is a process completely equivalent to the growth of diamond crystals. However, the accretion of macro-molecules must be $9 described in a way different from that used to describe the growth of crystals because so...

  19. Tribological properties of nanocrystalline diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, A.; Fenske, G.R.; Krauss, A.R.; Gruen, D.M.; McCauley, T.; Csencsits, R.T. [Argonne National Lab., IL (United States). Energy Technology Div.

    1999-11-01

    In this paper, we present the friction and wear properties of nanocrystalline diamond (NCD) films grown in Ar-fullerene (C{sub 60}) and Ar-CH{sub 4} microwave plasmas. Specifically, we will address the fundamental tribological issues posed by these films during sliding against Si{sub 3}N{sub 4} counterfaces in ambient air and inert gases. Grain sizes of the films grown by the new method are very small (10-30 nm) and are much smoother (20-40 nm, root mean square) than those of films grown by the conventional H{sub 2}-CH{sub 4} microwave-assisted chemical vapor deposition process. Transmission electron microscopy (TEM) revealed that the grain boundaries of these films are very sharp and free of nondiamond phases. The microcrystalline diamond films grown by most conventional methods consist of large grains and a rough surface finish, which can cause severe abrasion during sliding against other materials. The friction coefficients of films grown by the new method (i.e. in Ar-C{sub 60} and Ar-CH{sub 4} plasmas) are comparable with those of natural diamond, and wear damage on counterface materials is minimal. Fundamental tribological studies indicate that these films may undergo phase transformation during long-duration, high-speed and/or high-load sliding tests and that the transformation products trapped at the sliding interfaces can intermittently dominate friction and wear performance. Using results from a combination of TEM, electron diffraction, Raman spectroscopy, and electron energy loss spectroscopy, we describe the structural chemistry of the debris particles trapped at the sliding interfaces and elucidate their possible effects on friction and wear of NCD films in dry N{sub 2}. Finally, we suggest a few potential applications in which NCD films can improve performance and service lives. (orig.)

  20. Psychogenic Purpura (Gardner-Diamond Syndrome)

    Science.gov (United States)

    Bhattacharya, Gaurav

    2015-01-01

    Psychogenic purpura, also known as Gardner-Diamond syndrome or autoerythrocyte sensitization syndrome, is a rare condition characterized by spontaneous development of painful edematous skin lesions progressing to ecchymosis over the next 24 hours. Severe stress and emotional trauma always precede the skin lesions. The condition is most commonly seen in women, but isolated cases have been reported in adolescents and in males. Psychodermatologic evaluation and dermatology and psychiatry liaison have been successful in the treatment of these patients. This report provides an overview of psychogenic purpura and presents the case of a 15-year-old girl. PMID:26137346

  1. Doping and cluster formation in diamond

    KAUST Repository

    Schwingenschlö gl, Udo; Chroneos, Alexander; Grimes, R. W.; Schuster, Cosima

    2011-01-01

    Introducing a cluster formation model, we provide a rational fundamental viewpoint for the difficulty to achieve n-type dopeddiamond. We argue that codoping is the way forward to form appropriately doped shallow regions in diamond and other forms of carbon such as graphene. The electronegativities of the codopants are an important design criterion for the donor atom to efficiently donate its electron. We propose that the nearest neighbour codopants should be of a considerably higher electronegativity compared to the donor atom. Codoping strategies should focus on phosphorous for which there are a number of appropriate codopants.

  2. Doping and cluster formation in diamond

    KAUST Repository

    Schwingenschlögl, Udo

    2011-09-09

    Introducing a cluster formation model, we provide a rational fundamental viewpoint for the difficulty to achieve n-type dopeddiamond. We argue that codoping is the way forward to form appropriately doped shallow regions in diamond and other forms of carbon such as graphene. The electronegativities of the codopants are an important design criterion for the donor atom to efficiently donate its electron. We propose that the nearest neighbour codopants should be of a considerably higher electronegativity compared to the donor atom. Codoping strategies should focus on phosphorous for which there are a number of appropriate codopants.

  3. Nanofluids with plasma treated diamond nanoparticles

    International Nuclear Information System (INIS)

    Yu Qingsong; Kim, Young Jo; Ma Hongbin

    2008-01-01

    In this study, diamond nanoparticles were plasma treated by glow discharges of methane and oxygen with an aim of improving their dispersion characteristics in a base fluid of water and enhancing the thermal conductivity of the resulting nanofluids. It was found that, after plasma treatment, stable nanofluids with improved thermal conductivity were obtained without using any stabilizing agents. With <0.15 vol % addition of plasma treated nanoparticles into water, a 20% increase in thermal conductivity was achieved and a 5%-10% increase in both fluid density and viscosity was observed

  4. Quantum computing with defects in diamond

    International Nuclear Information System (INIS)

    Jelezko, F.; Gaebel, T.; Popa, I.; Domhan, M.; Wittmann, C.; Wrachtrup, J.

    2005-01-01

    Full text: Single spins in semiconductors, in particular associated with defect centers, are promising candidates for practical and scalable implementation of quantum computing even at room temperature. Such an implementation may also use the reliable and well known gate constructions from bulk nuclear magnetic resonance (NMR) quantum computing. Progress in development of quantum processor based on defects in diamond will be discussed. By combining optical microscopy, and magnetic resonance techniques, the first quantum logical operations on single spins in a solid are now demonstrated. The system is perspective for room temperature operation because of a weak dependence of decoherence on temperature (author)

  5. Thermal expansion of diamond at low temperatures.

    Science.gov (United States)

    Stoupin, Stanislav; Shvyd'ko, Yuri V

    2010-02-26

    Temperature variation of a lattice parameter of a synthetic diamond crystal (type IIa) was measured using high-energy-resolution x-ray Bragg diffraction in backscattering. A 2 order of magnitude improvement in the measurement accuracy allowed us to directly probe the linear thermal expansion coefficient at temperatures below 100 K. The lowest value measured was 2x10{-9} K-1. It was found that the coefficient deviates from the expected Debye law (T3) while no negative thermal expansion was observed. The anomalous behavior might be attributed to tunneling states due to low concentration impurities.

  6. The broad utility of Trizac diamond tile

    Science.gov (United States)

    Gagliardi, John I.; Romero, Vincent D.; Sventek, Bruce; Zu, Lijun

    2017-10-01

    Sample finishing data from a broad range of materials — glasses, sapphire, silicon carbide, silicon, zirconium oxide, lithium tantalate, and flooring materials — are shown effectively processed with Trizact™ Diamond Tile (TDT). This data should provide the reader with an understanding of what to expect when using TDT on hard to grind or brittle materials. Keys to maintaining effective TDT pad wear rates, and therefore cost effect and stable processes, are described as managing 1) the proper lubricant flow rate for glasses and silicon-type materials and 2) the conditioning particle concentration for harder-to-grind materials

  7. Nanostructured diamond coatings for orthopaedic applications

    Science.gov (United States)

    CATLEDGE, S.A.; THOMAS, V.; VOHRA, Y.K.

    2013-01-01

    With increasing numbers of orthopaedic devices being implanted, greater emphasis is being placed on ceramic coating technology to reduce friction and wear in mating total joint replacement components, in order to improve implant function and increase device lifespan. In this chapter, we consider ultra-hard carbon coatings, with emphasis on nanostructured diamond, as alternative bearing surfaces for metallic components. Such coatings have great potential for use in biomedical implants as a result of their extreme hardness, wear resistance, low friction and biocompatibility. These ultra-hard carbon coatings can be deposited by several techniques resulting in a wide variety of structures and properties. PMID:25285213

  8. A new neutron counter for fission research

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, B., E-mail: benoit.laurent@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Granier, T.; Bélier, G.; Chatillon, A.; Martin, J.-F.; Taieb, J. [CEA, DAM, DIF, F-91297 Arpajon (France); Hambsch, F.-J. [EC-JRC Institute for Reference Materials and Measurements (IRMM), Retieseweg, 2440 Geel (Belgium); Tovesson, F.; Laptev, A.B.; Haight, R.C.; Nelson, R.O.; O' Donnell, J.M. [Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-05-01

    A new neutron counter for research experiments on nuclear fission has been developed. This instrument is designed for the detection of prompt fission neutrons within relatively high levels of gamma and neutron background. It is composed of a set of {sup 3}He proportional counters arranged within a block of polyethylene which serves as moderator. The detection properties have been studied by means of Monte Carlo simulations and experiments with radioactive sources. These properties are confirmed by an experiment on neutron-induced fission of {sup 238}U at the WNR facility of the Los Alamos Neutron Science Center during which the mean prompt fission neutron multiplicity, or ν{sup ¯} has been measured from 1 to 20 MeV of incident neutron energy.

  9. Dead zone characteristics of a gas counter

    International Nuclear Information System (INIS)

    Nohtomi, Akihiro; Sakae, Takeji; Matoba, Masaru; Koori, Norihiko.

    1990-01-01

    The dead zone was recently defined as the product of dead length and dead time in order to describe the characteristics of the self-quenching streamer (SQS) mode of a gas counter. Investigation of the dead zone characteristics has been extended for the proportional and GM modes, and the measured dead zone has been compared with that of the SQS mode. Accurate values for the dead zone could be determined by means of a newly developed method with a pulse interval time to amplitude converter. Each operation mode indicates distinct dead zone characteristics. Properties of gas counters for high counting rates may be improved on the basis of measurements of the dead zone. (author)

  10. Pulse triggering mechanism of air proportional counters

    International Nuclear Information System (INIS)

    Aoyama, T.; Mori, T.; Watanabe, T.

    1983-01-01

    This paper describes the pulse triggering mechanism of a cylindrical proportional counter filled with air at atmospheric pressure for the incidence of β-rays. Experimental results indicate that primary electrons created distantly from the anode wire by a β-ray are transformed into negative ions, which then detach electrons close to the anode wire and generate electron avalanches thus triggering pulses, while electrons created near the anode wire by a β-ray directly trigger a pulse. Since a negative ion pulse is triggered by a single electron detached from a negative ion, multiple pulses are generated by a large number of ions produced by the incidence of a single β-ray. It is therefore necessary not to count pulses triggered by negative ions but to count those by primary electrons alone when use is made of air proportional counters for the detection of β-rays. (orig.)

  11. Sources of Brazil's Counter-Hegemony

    Directory of Open Access Journals (Sweden)

    Marcos Aurelio Guedes de Oliveira

    2010-01-01

    Full Text Available There have been two key initiatives taken in the last two decades in Brazil to create a counter-hegemonic project for the country. One initiative resulted from Brazil's business community and high-level State bureaucracy and aimed at forming a regional economic and political bloc that would guarantee and enlarge a relative independence from the hegemonic powers. The other resulted from the emergence of the new unionist movement in São Paulo and from the formation of Partido dos Trabalhadores and aimed at promoting radical democratization and reducing social exclusion. Both initiatives have created policies and changes that have converged to enhance Brazil's counter-hegemonic position as a regional and emerging power.

  12. Very large area multiwire spectroscopic proportional counters

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F.

    1981-01-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) succesfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm 2 with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results. (orig.)

  13. Very large area multiwire spectroscopic proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F. (Istituto di Astrofisica Spaziale, Frascati (Italy))

    1981-07-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) successfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm/sup 2/ with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results.

  14. Calibration of the neutron scintillation counter threshold

    International Nuclear Information System (INIS)

    Noga, V.I.; Ranyuk, Yu.N.; Telegin, Yu.N.

    1978-01-01

    A method for calibrating the threshold of a neutron counter in the form of a 10x10x40 cm plastic scintillator is described. The method is based on the evaluation of the Compton boundary of γ-spectrum from the discrimination curve of counter loading. The results of calibration using 60 Co and 24 Na γ-sources are given. In order to eValuate the Compton edge rapidly, linear extrapolation of the linear part of the discrimination curve towards its intersection with the X axis is recommended. Special measurements have shown that the calibration results do not practically depend on the distance between the cathode of a photomultiplier and the place where collimated γ-radiation of the calibration source reaches the scintillator

  15. Engaging Civil Society in Countering Violent Extremism

    Directory of Open Access Journals (Sweden)

    Bibi van Ginkel

    2012-08-01

    Full Text Available In this Research Paper Dr. Bibi van Ginkel takes an in depth look at how multi-lateral institutions, engage with civil society to counter violent extremism. Dr. van Ginkel argues that civil society can play a crucial role in preventing and countering violent extremism in numerous ways – by working on development programs, through their work in conflict transformation, in providing a platform to raise political grievances and to facilitate dialogue, or through their work in empowering victims and survivors of terrorism. The Paper finds that over the last decade there has been a more intensive coordination of activities between the UN and other multi-lateral organisations and civil society but the question remains whether the implementation as well as the drafting of these policies will live up to their potential effectiveness. This Paper gauges how effective these measures have been and what more there is to do. The final section concludes with a series of policy recommendations.

  16. Initial damage processes for diamond film exposure to hydrogen plasma

    International Nuclear Information System (INIS)

    Deslandes, A.; Guenette, M.C.; Samuell, C.M.; Karatchevtseva, I.; Ionescu, M.; Cohen, D.D.; Blackwell, B.; Corr, C.; Riley, D.P.

    2013-01-01

    Graphical abstract: -- Highlights: • Exposing chemical vapour deposited (CVD) diamond films in a recently constructed device, MAGPIE, specially commissioned to simulate fusion plasma conditions. • Non-diamond material is etched from the diamond. • There is no hydrogen retention observed, which suggests diamond is an excellent candidate for plasma facing materials. • Final structure of the surface is dependent on synergistic effects of etching and ion-induced structural change. -- Abstract: Diamond is considered to be a possible alternative to other carbon based materials as a plasma facing material in nuclear fusion devices due to its high thermal conductivity and resistance to chemical erosion. In this work CVD diamond films were exposed to hydrogen plasma in the MAGnetized Plasma Interaction Experiment (MAGPIE): a linear plasma device at the Australian National University which simulates plasma conditions relevant to nuclear fusion. Various negative sample stage biases of magnitude less than 500 V were applied to control the energies of impinging ions. Characterisation results from SEM, Raman spectroscopy and ERDA are presented. No measureable quantity of hydrogen retention was observed, this is either due to no incorporation of hydrogen into the diamond structure or due to initial incorporation as a hydrocarbon followed by subsequent etching back into the plasma. A model is presented for the initial stages of diamond erosion in fusion relevant hydrogen plasma that involves chemical erosion of non-diamond material from the surface by hydrogen radicals and damage to the subsurface region from energetic hydrogen ions. These results show that the initial damage processes in this plasma regime are comparable to previous studies of the fundamental processes as reported for less extreme plasma such as in the development of diamond films

  17. Light volatiles in diamond: Physical interpretation and genetic significance

    International Nuclear Information System (INIS)

    Sellschop, J.P.F.; Madiba, C.C.P.; Annegarn, H.J.

    1980-01-01

    Natural diamond is characterised in terms of features in the infra-red and ultra-violet spectra. Additionally electron spin resonance, X-ray diffraction and topography, cathodoluminescence, mechanical and electrical measurements have been used to give more detail to such specification. It had been concluded that the major impurity in diamond was nitrogen and hence most physical phenomena have been interpreted as a manifestation of the mode(s) of occurence of nitrogen. From neutron activation analysis studies some 58 elements have been identified in diamond, many of course at trace levels. It has been shown that these data reveal a distinctive trace and minor element chemistry for diamond. Recently ion beam analyses have quantified the role of nitrogen in diamond characterisation. Most recently ion beam analysis has revealed that hydrogen, nitrogen and oxygen are all major impurities in diamond. Quantitative studies have been made using ( 19 Fe,α), (α,n) and ( 3 He,p) reactions. High temperature annealing in ultra-high vacuum conditions results in a substantial increase in the hydrogen measured as well as in the shape of the depth profile. Hydrogen is released from defect centres and diffuses rapidly through the diamond. Some of these hydrogen atoms are trapped at defect sites which are concentrated near surface as a result of the ion beam bombardement. A lesser response to the annealing treatment is found for oxygen and the smallest change for nitrogen. These ion beam data lend independent support to our earlier interpretation of the neutron activation data that all diamonds contain defects distributed fairly uniformly and consisting of sub-microscopic inclusions, the elemental composition of which suggests that each is a magma droplet from the upper mantle in which the diamond crystallized. The water-richness of the magma is an essential feature of the diamond genesis conditions. (orig.)

  18. Data science implications in diamond formation and craton evolution

    Science.gov (United States)

    Pan, F.; Huang, F.; Fox, P. A.

    2017-12-01

    Diamonds are so-called "messengers" from the deep Earth. Fluid and mineral inclusions in diamonds could reflect the compositions of fluids/melts and wall-rocks in which diamond formed. Recently many diamond samples are examined to study the water content in the mantle transition zone1, the mechanism of diamond formation2 and the mantle evolution history3. However, most of the studies can only explain local activities. Therefore, an overall project of data grouping, comparison and correlation is needed, but limited progress has been made due to a lack of benchmark datasets on diamond formation and effective computing algorithms. In this study, we start by proposing the very first complete and easily-accessible dataset on mineral and fluid inclusions in diamonds. We rescue, collect and organize the data available from papers, journals and other publications resources ([2-4] and more), and then apply several state-of-the-art machine learning methods to tackle this earth science problem by clustering diamond formation process into distinct groups primarily based on the compositions, the formation temperature and pressure, the age and so on. Our ongoing work includes further data exploration and training existing models. Our preliminary results show that diamonds formed from older cratons usually have higher formation temperature. Also peridotitic diamonds take a much larger population than the ecologitic ones. More details are being discovered when we finish constructing the database and training our model. We expect the result to demonstrate the advantages of using machine learning and data science in earth science research problems. Our methodology for knowledge discovery are very general and can be broadly applied to other earth science research problems under the same framework.[1] Pearson et al, Nature (2014); [2] Tomlinson et al, EPSL (2006); [3] Weiss et al, Nature (2016); [4] Stachel and Harris, Ore Geology Reviews (2008); Weiss et al, EPSL (2013)

  19. Nucleation of microwave plasma CVD diamond on molybdenum (Mo) substrate

    International Nuclear Information System (INIS)

    Inderjeet, K.; Ramesh, S.

    2000-01-01

    Molybdenum is a metal, which is gaining increasing significance in industrial applications. The main use of Mo is as all alloying element added in small amounts to steel, irons and non- ferrous alloys in order to enhance the strength, toughness and wear resistance. Mo is also vastly being employed in the automotive and aircraft industries, mainly due to its low coefficient of friction. Diamond, on be other hand, is a unique material for innumerable applications because of its usual combination of physical and chemical properties. Several potential applications can be anticipated for diamond in many sectors including electronics, optics, as protective corrosion resistant coatings, cutting tools, etc. With the enhancement in science and technology, diamond microcrystals and thin films are now being produced from the vapour phase by a variety of chemical vapour deposition (CVD) techniques; such as microwave plasma CVD. With such technology being made available, it is envisage that diamond-coated molybdenum would further enhance the performance and to open up new avenue for Mo in various industries. Therefore, it is the aim of the present work to study the nucleation and growth of diamond particles on Mo surface by employing microwave plasma CVD (MAPCVD). In the present work, diamond deposition was carried out in several stages by varying the deposition distance. The nucleation and growth rate were studied using scanning electron microscopy (SEM). In addition, the existence of diamond was verified by X-ray diffraction (XRD) analysis. It has been found that the nucleation and growth rate of diamond particles were influenced by the deposition height between the substrate and plasma. Under the optimum condition, well defined diamond crystallites distributed homogeneously throughout the surface, could be obtained. Some of the important parameters controlling the deposition and growth of diamond particles on Mo surface are discussed. (author)

  20. Fast differential pulse discriminator-counter

    International Nuclear Information System (INIS)

    Shelevoj, K.D.

    1985-01-01

    The flowsheet of a differential pulse discriminator counter is described; the result of discrimination here is independent from the shape of the input pulse. Rate of the analysis of input pulses with minimum amplitude up to 0.3 mV coming out from the photomultiplier makes up 220 MHz. The flowsheet of the discriminator used in the system of photon counting for atmosphere probing is presented

  1. A position sensitive parallel plate avalanche counter

    International Nuclear Information System (INIS)

    Lombardi, M.; Tan Jilian; Potenza, R.; D'amico, V.

    1986-01-01

    A position sensitive parallel plate avalanche counter with a distributed constant delay-line-cathode (PSAC) is described. The strips formed on the printed board were served as the cathode and the delay line for readout of signals. The detector (PSAC) was operated in isobutane gas at the pressure range from 10 to 20 torr. The position resolution is better than 1 mm and the time resolution is about 350 ps, for 252 Cf fission-spectrum source

  2. Evaluating the US Counter-ISIL Strategy

    Science.gov (United States)

    2017-05-25

    strategy is actually addressing those critical capabilities and vulnerabilities. Finally, it explores alternative, whole-of-government strategies that...Counterterrorism Strategies as an Illustration. Santa Monica, CA: RAND Corporation , 2009. Enduring Leadership in a Dynamic World. Quadrennial Diplomacy...Evaluating the US Counter-ISIL Strategy A Monograph by LTC Jason A. Curl U.S. Army School of Advanced Military Studies United States Army

  3. Universal Fast Breeder Reactor Subassembly Counter manual

    International Nuclear Information System (INIS)

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications

  4. Universal Fast Breeder Reactor Subassembly Counter manual

    Energy Technology Data Exchange (ETDEWEB)

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications.

  5. Development of aerogel Cherenkov counters at Novosibirsk

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Baehr, J.; Bellunato, T.; Beloborodov, K.I.; Bobrovnikov, V.S.; Buzykaev, A.R.; Calvi, M.; Danilyuk, A.F.; Djordjadze, V.; Golubev, V.B.; Kononov, S.A.; Kravchenko, E.A.; Lipka, D.; Matteuzzi, C.; Musy, M.; Onuchin, A.P.; Perego, D.; Rodiakin, V.A.; Savinov, G.A.; Serednyakov, S.I.; Shamov, A.G.; Stephan, F.; Tayursky, V.A.; Vorobiov, A.I.

    2006-01-01

    The work on aerogel Cherenkov counters was started in Novosibirsk in 1986. Production of aerogels with refractive indices of 1.006-1.13 and thicknesses of blocks up to 50mm was developed. The light absorption length at 400nm is 5-7m, the scattering length is 4-5cm. By these parameters, the Novosibirsk aerogel is one of the best in the world. The ASHIPH Cherenkov counters with light collection on wavelength shifters have been developed. The ASHIPH system of the KEDR detector contains 1000l of aerogel. The π/K separation is 4.5σ. A project of ASHIPH counters for the SND detector has been developed. Aerogel RICH for LHCb gives a possibility to identify hadrons in the momentum range of 2-10GeV/c. The Novosibirsk group is developing an aerogel RICH for the endcap for the SuperBaBar project. Calculations performed by a group of physicists from Novosibirsk and DESY-Zeuthen have shown that aerogel radiators enable to achieve time resolution up to 20fs

  6. Which future for nuclear counter-proliferation?

    International Nuclear Information System (INIS)

    Duval, M.

    2010-01-01

    Dealing with the case of nuclear weapons possessed by nuclear states (but not eventually by terrorists), the author first identifies the constants of counter-proliferation: it is linked to interest conflicts between those who try to preserve their monopoly and those who try to acquire a new weapon either because of a threat or for reasons of regional prestige, the evolution from use to deterrence, the appearance of new actors after the USA and Russia, the role of nuclear tactical weapons, and the future of Russian weapons and know-how. He presents the international counter-proliferation context: the Non Proliferation Treaty (NPT), the IAEA and its controls, the Nuclear Supplier Group (NSG), the nuclear-free zones, the Comprehensive Test Ban Treaty (CTBT), the Missile Technology Control Regime (MTCR). He describes how and why proliferation occurs: uranium enrichment and plutonium technology, political reasons in different parts of the world. Then, he gives an overview of the proliferation status by commenting the cases of Israel, Iraq, India, Pakistan, North Korea, and Iran. He discusses the future of proliferation (involved countries, existence of a nuclear black market) and of counter-proliferation as far as Middle-East and North Korea are concerned. He tries finally to anticipate the consequences for nuclear deterrence strategy, and more particularly for Europe and France

  7. High pressure sintering (HP-HT) of diamond powders with titanium and titanium carbide

    International Nuclear Information System (INIS)

    Jaworska, L.

    1999-01-01

    Polycrystalline diamond compacts for cutting tools are mostly manufactured using high pressure sintering (HP-HT). The standard diamond compacts are prepared by diamond powders sintering with metallic binding phase. The first group of metallic binder are metals able to solve carbon - Co, Ni. The second group of metal binders are carbide forming elements - Ti, Cr, W and others. The paper describes high pressure sintering of diamond powder with titanium and nonstoichiometry titanium carbide for cutting tool application. A type of binding phase has the significant influence on microstructure and mechanical properties of diamond compacts. Very homogeneous structure was achieved in case of compacts obtained from metalized diamond where diamond-TiC-diamond connection were predominant. In the case of compacts prepared by mechanical mixing of diamond with titanium powders the obtained structure was nonhomogeneous with titanium carbide clusters. They had more diamond to diamond connections. These compacts compared to the compact made of metallized diamond have greater wear resistance. In the case of the diamond and TiC 0.92 sintering the strong bonding of TiC diamond grains was obtained. The microstructure observations for diamond with 5% wt. Ti and diamond with 5% wt. TiC 0.92 (the initial composition) compacts were performed in transmission microscope. For two type of compacts the strong bonding phase TiC without defects is creating. (author)

  8. Adherent diamond film deposited on Cu substrate by carbon transport from nanodiamond buried under Pt interlayer

    International Nuclear Information System (INIS)

    Liu Xuezhang; Wei Qiuping; Yu Zhiming; Yang Taiming; Zhai Hao

    2013-01-01

    Highlights: ► Adherent polycrystalline diamond films were grown on copper substrate by carbon transport. ► The nucleation density was increased to 10 11 cm −2 . ► Diamond films were a composite structure of nano-crystalline diamond layer and micro-crystalline diamond layer. ► Diamond nucleation was based by carbon dissolving from UDDs to Pt interlayer and formation of sp 3 -bonded diamond clusters at the Pt surface. - Abstract: Diamond film deposited on Cu suffered from poor adhesion mainly due to the large mismatch of thermal expansion coefficients and the lack of affinity between carbon and Cu. Enhancing diamond nucleation by carbon transport from buried nanodiamond through a Pt ultrathin interlayer, adherent diamond film was then deposited on Cu substrate without distinctly metallic interlayer. This novel nucleation mechanism increased diamond nucleation density to 10 11 cm −2 , and developed diamond film with a composite structure of nano-crystalline diamond (NCD) layer and micro-crystalline diamond layer. Diamond film was characterized by the scanning electron microscope (SEM) and Raman spectroscope, respectively. The composition of diamond film/Cu substrate interface was examined by electron probe microanalysis (EPMA). The adhesion of diamond film was evaluated by indentation test. Those results show that a Pt ultrathin interlayer provides stronger chemically bonded interfaces and improve film adhesion.

  9. Adherent diamond film deposited on Cu substrate by carbon transport from nanodiamond buried under Pt interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xuezhang [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Wei Qiuping, E-mail: qiupwei@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Yu Zhiming, E-mail: zhiming@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Yang Taiming; Zhai Hao [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Adherent polycrystalline diamond films were grown on copper substrate by carbon transport. Black-Right-Pointing-Pointer The nucleation density was increased to 10{sup 11} cm{sup -2}. Black-Right-Pointing-Pointer Diamond films were a composite structure of nano-crystalline diamond layer and micro-crystalline diamond layer. Black-Right-Pointing-Pointer Diamond nucleation was based by carbon dissolving from UDDs to Pt interlayer and formation of sp{sup 3}-bonded diamond clusters at the Pt surface. - Abstract: Diamond film deposited on Cu suffered from poor adhesion mainly due to the large mismatch of thermal expansion coefficients and the lack of affinity between carbon and Cu. Enhancing diamond nucleation by carbon transport from buried nanodiamond through a Pt ultrathin interlayer, adherent diamond film was then deposited on Cu substrate without distinctly metallic interlayer. This novel nucleation mechanism increased diamond nucleation density to 10{sup 11} cm{sup -2}, and developed diamond film with a composite structure of nano-crystalline diamond (NCD) layer and micro-crystalline diamond layer. Diamond film was characterized by the scanning electron microscope (SEM) and Raman spectroscope, respectively. The composition of diamond film/Cu substrate interface was examined by electron probe microanalysis (EPMA). The adhesion of diamond film was evaluated by indentation test. Those results show that a Pt ultrathin interlayer provides stronger chemically bonded interfaces and improve film adhesion.

  10. Geochemistry of single diamond crystals by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Damarupurshad, A.

    1995-02-01

    Neutron activation analysis is probably the most powerful technique, available to date, for the analysis of the trace elements in diamond. In this study the technique of neutron activation analysis has been modified and optimized for the analysis of single, small (0.01-0.5 carat), inclusion-bearing and inclusion-free diamonds. Instrumental neutron activation analysis was used to analyze for up to 40 different elements at the ppb and ppt levels in diamonds from Brazil, South Africa, Colorado and China. The data obtained was used to detect and understand the differences between diamonds from the eclogitic and peridotitic para geneses and between diamonds from the different localities. In this regard, two inter element ratios, i.e. Cr/Sc and Au/Ir ratios were found to be useful. It seems that diamonds from a particular locality or mine have a unique range of Cr/Sc ratios. Furthermore, the identity of the dominant silicate inclusion(s) can be deduced from the Cr/Sc ratio of the diamond, since each type of silicate inclusion has a different range of Cr/Sc ratios. Not only is the Cr/Sc ratio distinctive for silicate inclusions in diamonds, it is also distinctive for minerals co genetic with diamond, such as orange garnet, red garnet, chrome diopside and ortho pyroxene (macrocrysts) which were separated from kimberlites. Sulphide inclusions may also contain detectable quantities of Au and Ir and the ratios of these two elements can also be used to differentiate between diamonds of the two para geneses. Carbon isotope ratios of these eclogitic and peridotitic diamonds were also measured. The comparison of this with the Cr/Sc ratios revealed that the carbon isotope ratios of both para geneses overlap in a narrow range and do not show the clear separations seen with Cr/Sc and Au/Ir ratios. It can be suggested, therefore, on the basis of the suite of 61 diamonds analyzed in this study, that the Cr/Sc and Au/Ir ratios are much more useful tools to distinguish between diamonds

  11. Studies of defects on ion irradiated diamond

    Energy Technology Data Exchange (ETDEWEB)

    Lai, P F; Prawer, S; Spargo, A E.C.; Bursill, L A [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    It is known that diamond is amorphized or graphitized when irradiated above a critical dose. Above this critical dose, D{sub c}, the resistance R is found to drop very rapidly due to the formation of graphite regions which overlap at D{sub c} to form a semi-continuous electrically conducting pathway through the sample. One particularly interesting method of studying this transformation is electron energy-loss spectroscopy (EELS). Using EELS, the different phases of carbon can be identified and distinguished from each other using the extended energy-loss fine structure (EXELFS) of the core-loss part of the spectrum. EELS is a sensitive method for determining the electronic structure of small areas of a sample. In this paper, transmission electron microscopy (TEM) and EELS measurements of the ion irradiated diamond were combined in an attempt to correlate the microstructural nature of the ion-beam induced damage to the changes in the electrical and other properties. 7 refs., 1 tab., 2 figs.

  12. Studies of defects on ion irradiated diamond

    Energy Technology Data Exchange (ETDEWEB)

    Lai, P.F.; Prawer, S.; Spargo, A.E.C.; Bursill, L.A. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    It is known that diamond is amorphized or graphitized when irradiated above a critical dose. Above this critical dose, D{sub c}, the resistance R is found to drop very rapidly due to the formation of graphite regions which overlap at D{sub c} to form a semi-continuous electrically conducting pathway through the sample. One particularly interesting method of studying this transformation is electron energy-loss spectroscopy (EELS). Using EELS, the different phases of carbon can be identified and distinguished from each other using the extended energy-loss fine structure (EXELFS) of the core-loss part of the spectrum. EELS is a sensitive method for determining the electronic structure of small areas of a sample. In this paper, transmission electron microscopy (TEM) and EELS measurements of the ion irradiated diamond were combined in an attempt to correlate the microstructural nature of the ion-beam induced damage to the changes in the electrical and other properties. 7 refs., 1 tab., 2 figs.

  13. Anodic oxidation of benzoquinone using diamond anode.

    Science.gov (United States)

    Panizza, Marco

    2014-01-01

    The anodic degradation of 1,4-benzoquinone (BQ), one of the most toxic xenobiotic, was investigated by electrochemical oxidation at boron-doped diamond anode. The electrolyses have been performed in a single-compartment flow cell in galvanostatic conditions. The influence of applied current (0.5-2 A), BQ concentration (1-2 g dm(-3)), temperature (20-45 °C) and flow rate (100-300 dm(3) h(-1)) has been studied. BQ decay kinetic, the evolution of its oxidation intermediates and the mineralization of the aqueous solutions were monitored during the electrolysis by high-performance liquid chromatograph (HPLC) and chemical oxygen demand (COD) measurements. The results obtained show that the use of diamond anode leads to total mineralization of BQ in any experimental conditions due to the production of oxidant hydroxyl radicals electrogenerated from water discharge. The decay kinetics of BQ removal follows a pseudo-first-order reaction, and the rate constant increases with rising current density. The COD removal rate was favoured by increasing of applied current, recirculating flow rate and it is almost unaffected by solution temperature.

  14. Topical review: spins and mechanics in diamond

    Science.gov (United States)

    Lee, Donghun; Lee, Kenneth W.; Cady, Jeffrey V.; Ovartchaiyapong, Preeti; Bleszynski Jayich, Ania C.

    2017-03-01

    There has been rapidly growing interest in hybrid quantum devices involving a solid-state spin and a macroscopic mechanical oscillator. Such hybrid devices create exciting opportunities to mediate interactions between disparate quantum bits (qubits) and to explore the quantum regime of macroscopic mechanical objects. In particular, a system consisting of the nitrogen-vacancy defect center (NV center) in diamond coupled to a high-quality-factor mechanical oscillator is an appealing candidate for such a hybrid quantum device, as it utilizes the highly coherent and versatile spin properties of the defect center. In this paper, we will review recent experimental progress on diamond-based hybrid quantum devices in which the spin and orbital dynamics of single defects are driven by the motion of a mechanical oscillator. In addition, we discuss prospective applications for this device, including long-range, phonon-mediated spin-spin interactions, and phonon cooling in the quantum regime. We conclude the review by evaluating the experimental limitations of current devices and identifying alternative device architectures that may reach the strong coupling regime.

  15. Hardware support for software controlled fast multiplexing of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W.

    2013-01-01

    Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

  16. A Review on the Low-Dimensional and Hybridized Nanostructured Diamond Films

    Directory of Open Access Journals (Sweden)

    Hongdong Li

    2015-01-01

    Full Text Available In the last decade, besides the breakthrough of high-rate growth of chemical vapor deposited single-crystal diamonds, numerous nanostructured diamond films have been rapidly developed in the research fields of the diamond-based sciences and industrial applications. The low-dimensional diamonds of two-dimensional atomic-thick nanofilms and nanostructural diamond on the surface of bulk diamond films have been theoretically and experimentally investigated. In addition, the diamond-related hybrid nanostructures of n-type oxide/p-type diamond and n-type nitride/p-type diamond, having high performance physical and chemical properties, are proposed for further applications. In this review, we first briefly introduce the three categories of diamond nanostructures and then outline the current advances in these topics, including their design, fabrication, characterization, and properties. Finally, we address the remaining challenges in the research field and the future activities.

  17. Fabrication of planarised conductively patterned diamond for bio-applications

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Wei [School of Physics, University of Melbourne, Parkville, Victoria (Australia); Fox, Kate, E-mail: kfox@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, Victoria (Australia); Ganesan, Kumaravelu [School of Physics, University of Melbourne, Parkville, Victoria (Australia); Turnley, Ann M. [Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria (Australia); Shimoni, Olga [School of Physics, University of Melbourne, Parkville, Victoria (Australia); Tran, Phong A. [Department of Chemical and Biomolecular Engineering, University of Melbourne, Parkville, Victoria (Australia); Lohrmann, Alexander; McFarlane, Thomas; Ahnood, Arman; Garrett, David J. [School of Physics, University of Melbourne, Parkville, Victoria (Australia); Meffin, Hamish [National Information and Communication Technology Australia, Victoria 3010 (Australia); Department of Electrical and Electronic Engineering, University of Melbourne, Victoria 3010 (Australia); O' Brien-Simpson, Neil M.; Reynolds, Eric C. [Oral Health Cooperative Research Centre, Melbourne Dental School, The University of Melbourne, 720 Swanston Street, Victoria 3010 (Australia); Prawer, Steven [School of Physics, University of Melbourne, Parkville, Victoria (Australia)

    2014-10-01

    The development of smooth, featureless surfaces for biomedical microelectronics is a challenging feat. Other than the traditional electronic materials like silicon, few microelectronic circuits can be produced with conductive features without compromising the surface topography and/or biocompatibility. Diamond is fast becoming a highly sought after biomaterial for electrical stimulation, however, its inherent surface roughness introduced by the growth process limits its applications in electronic circuitry. In this study, we introduce a fabrication method for developing conductive features in an insulating diamond substrate whilst maintaining a planar topography. Using a combination of microwave plasma enhanced chemical vapour deposition, inductively coupled plasma reactive ion etching, secondary diamond growth and silicon wet-etching, we have produced a patterned substrate in which the surface roughness at the interface between the conducting and insulating diamond is approximately 3 nm. We also show that the patterned smooth topography is capable of neuronal cell adhesion and growth whilst restricting bacterial adhesion. - Highlights: • We have fabricated a planar diamond device with conducting and insulating features. • A precise method is provided using CVD and RIE techniques to develop the substrate. • The step between conducting and insulating features is less than 3 nm. • Planar topography promotes neuronal cell adhesion and restricts bacterial adhesion. • Neuronal cells prefer conductive diamond (N-UNCD) to non-conductive diamond (UNCD)

  18. P-type diamond stripper foils for tandem ion accelerators

    International Nuclear Information System (INIS)

    Phelps, A.W.; Koba, R.

    1989-01-01

    The authors are developing a stripper foil composed of a p-type diamond membrane. This diamond stripper foil should have a significantly longer lifetime than any conventional stripper foil material. To be useful for stripper foils, the boron-doped blue diamond films must be thinner than 0.8 μm and pore-free. Two methods are compared for their ability to achieve a high nucleation areal density on a W substrate. Some W substrates were first coated with think layer of boron (≤20 nm) in order to enhance nucleation. Other W substrates were scratched with submicron diamond particles. A schematic diagram of the stripper foil is shown. Stripper foils were created by etching away the central area of W substrates. The diamond membrane was then supported by an annulus of W. Tungsten was selected as a ring-support material because of its high electrical and thermal conductivity, relatively low thermal expansion, and proven suitability as a substrate for diamond CVD. Warping or fracture of the diamond film after substrate etch-back was investigated

  19. Nuclear techniques of analysis in diamond synthesis and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, D. N.; Prawer, S.; Gonon, P.; Walker, R.; Dooley, S.; Bettiol, A.; Pearce, J. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    Nuclear techniques of analysis have played an important role in the study of synthetic and laser annealed diamond. These measurements have mainly used ion beam analysis with a focused MeV ion beam in a nuclear microprobe system. A variety of techniques have been employed. One of the most important is nuclear elastic scattering, sometimes called non-Rutherford scattering, which has been used to accurately characterise diamond films for thickness and composition. This is possible by the use of a database of measured scattering cross sections. Recently, this work has been extended and nuclear elastic scattering cross sections for both natural boron isotopes have been measured. For radiation damaged diamond, a focused laser annealing scheme has been developed which produces near complete regrowth of MeV phosphorus implanted diamonds. In the laser annealed regions, proton induced x-ray emission has been used to show that 50 % of the P atoms occupy lattice sites. This opens the way to produce n-type diamond for microelectronic device applications. All these analytical applications utilize a focused MeV microbeam which is ideally suited for diamond analysis. This presentation reviews these applications, as well as the technology of nuclear techniques of analysis for diamond with a focused beam. 9 refs., 6 figs.

  20. Nuclear techniques of analysis in diamond synthesis and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, D N; Prawer, S; Gonon, P; Walker, R; Dooley, S; Bettiol, A; Pearce, J [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    Nuclear techniques of analysis have played an important role in the study of synthetic and laser annealed diamond. These measurements have mainly used ion beam analysis with a focused MeV ion beam in a nuclear microprobe system. A variety of techniques have been employed. One of the most important is nuclear elastic scattering, sometimes called non-Rutherford scattering, which has been used to accurately characterise diamond films for thickness and composition. This is possible by the use of a database of measured scattering cross sections. Recently, this work has been extended and nuclear elastic scattering cross sections for both natural boron isotopes have been measured. For radiation damaged diamond, a focused laser annealing scheme has been developed which produces near complete regrowth of MeV phosphorus implanted diamonds. In the laser annealed regions, proton induced x-ray emission has been used to show that 50 % of the P atoms occupy lattice sites. This opens the way to produce n-type diamond for microelectronic device applications. All these analytical applications utilize a focused MeV microbeam which is ideally suited for diamond analysis. This presentation reviews these applications, as well as the technology of nuclear techniques of analysis for diamond with a focused beam. 9 refs., 6 figs.

  1. Nanofocusing optics for synchrotron radiation made from polycrystalline diamond.

    Science.gov (United States)

    Fox, O J L; Alianelli, L; Malik, A M; Pape, I; May, P W; Sawhney, K J S

    2014-04-07

    Diamond possesses many extreme properties that make it an ideal material for fabricating nanofocusing x-ray optics. Refractive lenses made from diamond are able to focus x-ray radiation with high efficiency but without compromising the brilliance of the beam. Electron-beam lithography and deep reactive-ion etching of silicon substrates have been used in a transfer-molding technique to fabricate diamond optics with vertical and smooth sidewalls. Latest generation compound refractive lenses have seen an improvement in the quality and uniformity of the optical structures, resulting in an increase in their focusing ability. Synchrotron beamline tests of two recent lens arrays, corresponding to two different diamond morphologies, are described. Focal line-widths down to 210 nm, using a nanocrystalline diamond lens array and a beam energy of E = 11 keV, and 230 nm, using a microcrystalline diamond lens at E = 15 keV, have been measured using the Diamond Light Source Ltd. B16 beamline. This focusing prowess is combined with relatively high transmission through the lenses compared with silicon refractive designs and other diffractive optics.

  2. Twinning of cubic diamond explains reported nanodiamond polymorphs

    Science.gov (United States)

    Németh, Péter; Garvie, Laurence A. J.; Buseck, Peter R.

    2015-12-01

    The unusual physical properties and formation conditions attributed to h-, i-, m-, and n-nanodiamond polymorphs has resulted in their receiving much attention in the materials and planetary science literature. Their identification is based on diffraction features that are absent in ordinary cubic (c-) diamond (space group: Fd-3m). We show, using ultra-high-resolution transmission electron microscope (HRTEM) images of natural and synthetic nanodiamonds, that the diffraction features attributed to the reported polymorphs are consistent with c-diamond containing abundant defects. Combinations of {113} reflection and rotation twins produce HRTEM images and d-spacings that match those attributed to h-, i-, and m-diamond. The diagnostic features of n-diamond in TEM images can arise from thickness effects of c-diamonds. Our data and interpretations strongly suggest that the reported nanodiamond polymorphs are in fact twinned c-diamond. We also report a new type of twin ( rotational), which can give rise to grains with dodecagonal symmetry. Our results show that twins are widespread in diamond nanocrystals. A high density of twins could strongly influence their applications.

  3. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    International Nuclear Information System (INIS)

    Hathwar, Raghuraj; Dutta, Maitreya; Chowdhury, Srabanti; Goodnick, Stephen M.; Koeck, Franz A. M.; Nemanich, Robert J.

    2016-01-01

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco ® Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures

  4. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    Science.gov (United States)

    Hathwar, Raghuraj; Dutta, Maitreya; Koeck, Franz A. M.; Nemanich, Robert J.; Chowdhury, Srabanti; Goodnick, Stephen M.

    2016-06-01

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco® Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures

  5. Temperature dependent simulation of diamond depleted Schottky PIN diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hathwar, Raghuraj; Dutta, Maitreya; Chowdhury, Srabanti; Goodnick, Stephen M. [Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287-8806 (United States); Koeck, Franz A. M.; Nemanich, Robert J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-8806 (United States)

    2016-06-14

    Diamond is considered as an ideal material for high field and high power devices due to its high breakdown field, high lightly doped carrier mobility, and high thermal conductivity. The modeling and simulation of diamond devices are therefore important to predict the performances of diamond based devices. In this context, we use Silvaco{sup ®} Atlas, a drift-diffusion based commercial software, to model diamond based power devices. The models used in Atlas were modified to account for both variable range and nearest neighbor hopping transport in the impurity bands associated with high activation energies for boron doped and phosphorus doped diamond. The models were fit to experimentally reported resistivity data over a wide range of doping concentrations and temperatures. We compare to recent data on depleted diamond Schottky PIN diodes demonstrating low turn-on voltages and high reverse breakdown voltages, which could be useful for high power rectifying applications due to the low turn-on voltage enabling high forward current densities. Three dimensional simulations of the depleted Schottky PIN diamond devices were performed and the results are verified with experimental data at different operating temperatures.

  6. Surface Texturing of CVD Diamond Assisted by Ultrashort Laser Pulses

    Directory of Open Access Journals (Sweden)

    Daniele M. Trucchi

    2017-11-01

    Full Text Available Diamond is a wide bandgap semiconductor with excellent physical properties which allow it to operate under extreme conditions. However, the technological use of diamond was mostly conceived for the fabrication of ultraviolet, ionizing radiation and nuclear detectors, of electron emitters, and of power electronic devices. The use of nanosecond pulse excimer lasers enabled the microstructuring of diamond surfaces, and refined techniques such as controlled ablation through graphitization and etching by two-photon surface excitation are being exploited for the nanostructuring of diamond. On the other hand, ultrashort pulse lasers paved the way for a more accurate diamond microstructuring, due to reduced thermal effects, as well as an effective surface nanostructuring, based on the formation of periodic structures at the nanoscale. It resulted in drastic modifications of the optical and electronic properties of diamond, of which “black diamond” films are an example for future high-temperature solar cells as well as for advanced optoelectronic platforms. Although experiments on diamond nanostructuring started almost 20 years ago, real applications are only today under implementation.

  7. Cyclic voltammetry response of an undoped CVD diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Fabisiak, K., E-mail: kfab@ukw.edu.pl [Institute of Physics, Kazimierz Wielki University, Powstancow Wielkopolskich 2, 85-090 Bydgoszcz (Poland); Torz-Piotrowska, R. [Faculty of Chemical Technology and Engineering, UTLS Seminaryjna 3, 85-326 Bydgoszcz (Poland); Staryga, E. [Institute of Physics, Technical University of Lodz, Wolczanska 219, 90-924 Lodz (Poland); Szybowicz, M. [Faculty of Technical Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); Paprocki, K.; Popielarski, P.; Bylicki, F. [Institute of Physics, Kazimierz Wielki University, Powstancow Wielkopolskich 2, 85-090 Bydgoszcz (Poland); Wrzyszczynski, A. [Institute of Physics, Technical University of Lodz, Wolczanska 219, 90-924 Lodz (Poland)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Correlation was found between diamond quality and its electrochemical performance. Black-Right-Pointing-Pointer The electrode sensitivity depends on the content of sp{sup 2} carbon phase in diamond layer. Black-Right-Pointing-Pointer The sp{sup 2} carbon phase content has little influence on the CV peak separation ({Delta}E{sub p}). - Abstract: The polycrystalline undoped diamond layers were deposited on tungsten wire substrates by using hot filament chemical vapor deposition (HFCVD) technique. As a working gas the mixture of methanol in excess of hydrogen was used. The morphologies and quality of as-deposited films were monitored by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy respectively. The electrochemical activity of the obtained diamond layers was monitored by using cyclic voltammetry measurements. Analysis of the ferrocyanide-ferricyanide couple at undoped diamond electrode suggests that electrochemical reaction at diamond electrode has a quasireversibile character. The ratio of the anodic and cathodic peak currents was always close to unity. In this work we showed that the amorphous carbon admixture in the CVD diamond layer has a crucial influence on its electrochemical performance.

  8. Diamond and silicon pixel detectors in high radiation environments

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, Jieh-Wen

    2012-10-15

    Diamond pixel detector is a promising candidate for tracking of collider experiments because of the good radiation tolerance of diamond. The diamond pixel detector must withstand the radiation damage from 10{sup 16} particles per cm{sup 2}, which is the expected total fluence in High Luminosity Large Hadron Collider. The performance of diamond and silicon pixel detectors are evaluated in this research in terms of the signal-to-noise ratio (SNR). Single-crystal diamond pixel detectors with the most recent readout chip ATLAS FE-I4 are produced and characterized. Based on the results of the measurement, the SNR of diamond pixel detector is evaluated as a function of radiation fluence, and compared to that of planar-silicon ones. The deterioration of signal due to radiation damage is formulated using the mean free path of charge carriers in the sensor. The noise from the pixel readout circuit is simulated and calculated with leakage current and input capacitance to the amplifier as important parameters. The measured SNR shows good agreement with the calculated and simulated results, proving that the performance of diamond pixel detectors can exceed the silicon ones if the particle fluence is more than 10{sup 15} particles per cm{sup 2}.

  9. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry

    International Nuclear Information System (INIS)

    Petitfils, A.

    2007-09-01

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  10. Polycrystalline-Diamond MEMS Biosensors Including Neural Microelectrode-Arrays

    Directory of Open Access Journals (Sweden)

    Donna H. Wang

    2011-08-01

    Full Text Available Diamond is a material of interest due to its unique combination of properties, including its chemical inertness and biocompatibility. Polycrystalline diamond (poly-C has been used in experimental biosensors that utilize electrochemical methods and antigen-antibody binding for the detection of biological molecules. Boron-doped poly-C electrodes have been found to be very advantageous for electrochemical applications due to their large potential window, low background current and noise, and low detection limits (as low as 500 fM. The biocompatibility of poly-C is found to be comparable, or superior to, other materials commonly used for implants, such as titanium and 316 stainless steel. We have developed a diamond-based, neural microelectrode-array (MEA, due to the desirability of poly-C as a biosensor. These diamond probes have been used for in vivo electrical recording and in vitro electrochemical detection. Poly-C electrodes have been used for electrical recording of neural activity. In vitro studies indicate that the diamond probe can detect norepinephrine at a 5 nM level. We propose a combination of diamond micro-machining and surface functionalization for manufacturing diamond pathogen-microsensors.

  11. Nuclear techniques of analysis in diamond synthesis and annealing

    International Nuclear Information System (INIS)

    Jamieson, D. N.; Prawer, S.; Gonon, P.; Walker, R.; Dooley, S.; Bettiol, A.; Pearce, J.

    1996-01-01

    Nuclear techniques of analysis have played an important role in the study of synthetic and laser annealed diamond. These measurements have mainly used ion beam analysis with a focused MeV ion beam in a nuclear microprobe system. A variety of techniques have been employed. One of the most important is nuclear elastic scattering, sometimes called non-Rutherford scattering, which has been used to accurately characterise diamond films for thickness and composition. This is possible by the use of a database of measured scattering cross sections. Recently, this work has been extended and nuclear elastic scattering cross sections for both natural boron isotopes have been measured. For radiation damaged diamond, a focused laser annealing scheme has been developed which produces near complete regrowth of MeV phosphorus implanted diamonds. In the laser annealed regions, proton induced x-ray emission has been used to show that 50 % of the P atoms occupy lattice sites. This opens the way to produce n-type diamond for microelectronic device applications. All these analytical applications utilize a focused MeV microbeam which is ideally suited for diamond analysis. This presentation reviews these applications, as well as the technology of nuclear techniques of analysis for diamond with a focused beam. 9 refs., 6 figs

  12. THIN DIAMOND FILMS FOR SNS H INJECTIONS STRIPPING

    International Nuclear Information System (INIS)

    SHAW, R.W.; HERR, A.D.; FEIGERLE, C.S.; CUTLER, R.J.; LIAW, C.J.; LEE, Y.Y.

    2004-01-01

    We have investigated the preparation and testing of thin diamond foils for use in stripping the SNS H - Linac beam. A long useful lifetime for these foils is desirable to improve operational efficiency. Preliminary data presented at PAC 2001 indicated that diamond foils were superior to conventional evaporated carbon foils, exhibiting lifetimes approximately five-fold longer [1]. That work employed a fully supported diamond foil, a format that is not acceptable for the SNS application; at least two edges of the approximately 1 x 1 cm foils must be free standing to allow for beam rastering. Residual stress in a chemical vapor deposited (CVD) diamond foil results in film distortion (scrolling) when the film is released from its silicon growth substrate. We have attacked this problem by initially patterning the surface of CVD growth substrates with a 50 or 100 line/inch trapezoidal grating, followed by conformal diamond film growth on the patterned substrate. Then removal of the substrate by chemical etching produced a foil that possessed improved mechanical integrity due to its corrugation. The high nucleation density required to grow continuous, pinhole free diamond foils of the desired thickness (1 (micro)m, 350 (micro)g/cm 2 ) was achieved by a combination of substrate surface scratching and seeding. A variety of diamond foils have been tested using the BNL 750 keV Radio Frequency Quadrupole H - beam to simulate energy loss in the SNS. Those include flat, corrugated, microcrystalline, and nanocrystalline foils. Foil lifetimes are reported

  13. Neutron detection at jet using artificial diamond detectors

    International Nuclear Information System (INIS)

    Pillon, M.; Angelone, M.; Lattanzi, D.; Marinelli, M.; Milani, E.; Tucciarone, A.; Verona-Rinati, G.; Popovichev, S.; Montereali, R.M.; Vincenti, M.A.; Murari, A.

    2007-01-01

    Artificial diamond neutron detectors recently proved to be promising devices to measure the neutron production on large experimental fusion machines. Diamond detectors are very promising detectors to be used in fusion environment due to their radiation hardness, low sensitivity to gamma rays, fast response and high energy resolution. High quality 'electronic grade' diamond films are produced through microwave chemical vapour deposition (CVD) technique. Two CVD diamond detectors have been installed and operated at joint European torus (JET), Culham Science Centre, UK. One of these detectors was a polycrystalline CVD diamond film; about 12 mm 2 area and 30 μm thickness while the second was a monocrystalline film of about 5 mm 2 area and 20 μm thick. Both diamonds were covered with 2 μm of lithium fluoride (LiF) 95% enriched in 6 Li. The LiF layer works as a neutron-to-charged particle converter so these detectors can measure thermalized neutrons. Their output signals were compared to JET total neutron yield monitors (KN1 diagnostic) realized with a set of uranium fission chambers. Despite their small active volumes the diamond detectors were able to measure total neutron yields with good reliability and stability during the recent JET experimental campaign of 2006

  14. Diamond and silicon pixel detectors in high radiation environments

    International Nuclear Information System (INIS)

    Tsung, Jieh-Wen

    2012-10-01

    Diamond pixel detector is a promising candidate for tracking of collider experiments because of the good radiation tolerance of diamond. The diamond pixel detector must withstand the radiation damage from 10 16 particles per cm 2 , which is the expected total fluence in High Luminosity Large Hadron Collider. The performance of diamond and silicon pixel detectors are evaluated in this research in terms of the signal-to-noise ratio (SNR). Single-crystal diamond pixel detectors with the most recent readout chip ATLAS FE-I4 are produced and characterized. Based on the results of the measurement, the SNR of diamond pixel detector is evaluated as a function of radiation fluence, and compared to that of planar-silicon ones. The deterioration of signal due to radiation damage is formulated using the mean free path of charge carriers in the sensor. The noise from the pixel readout circuit is simulated and calculated with leakage current and input capacitance to the amplifier as important parameters. The measured SNR shows good agreement with the calculated and simulated results, proving that the performance of diamond pixel detectors can exceed the silicon ones if the particle fluence is more than 10 15 particles per cm 2 .

  15. Twinning of cubic diamond explains reported nanodiamond polymorphs.

    Science.gov (United States)

    Németh, Péter; Garvie, Laurence A J; Buseck, Peter R

    2015-12-16

    The unusual physical properties and formation conditions attributed to h-, i-, m-, and n-nanodiamond polymorphs has resulted in their receiving much attention in the materials and planetary science literature. Their identification is based on diffraction features that are absent in ordinary cubic (c-) diamond (space group: Fd-3m). We show, using ultra-high-resolution transmission electron microscope (HRTEM) images of natural and synthetic nanodiamonds, that the diffraction features attributed to the reported polymorphs are consistent with c-diamond containing abundant defects. Combinations of {113} reflection and rotation twins produce HRTEM images and d-spacings that match those attributed to h-, i-, and m-diamond. The diagnostic features of n-diamond in TEM images can arise from thickness effects of c-diamonds. Our data and interpretations strongly suggest that the reported nanodiamond polymorphs are in fact twinned c-diamond. We also report a new type of twin ( rotational), which can give rise to grains with dodecagonal symmetry. Our results show that twins are widespread in diamond nanocrystals. A high density of twins could strongly influence their applications.

  16. Response of CVD diamond detectors to alpha radiation

    Energy Technology Data Exchange (ETDEWEB)

    Souw, E.-K. [Brookhaven National Lab., Upton, NY (United States); Meilunas, R.J. [Northrop-Grumman Corporation, Bethpage, NY 11714-3582 (United States)

    1997-11-21

    This article describes some results from an experiment with CVD diamond films used as {alpha} particle detectors. It demonstrates that bulk polarization can be effectively stopped within a reasonable time interval. This will enable detector calibration and quantitative measurement. A possible mechanism for the observed polarization quenching is discussed. It involves two types of carrier traps and a tentative band-gap model derived from the results of photoconductive current measurements. The experiment was set up mainly to investigate {alpha} detection properties of polycrystalline diamond films grown by the technique of microwave plasma enhanced chemical vapor deposition. For comparison, two commercially purchased diamond wafers were also investigated, i.e., one grown by the DC arc jet method, and the other, a type-IIa natural diamond wafer (not preselected). The best response to {alpha} particles was obtained using diamond thin-films grown by the microwave PECVD method, followed by the type-IIa natural diamond, and finally, the CVD diamond grown by the DC arc jet technique. (orig.). 43 refs.

  17. Consumer Preferences for High Welfare Meat in Germany: Self-service Counter or Service Counter?

    Directory of Open Access Journals (Sweden)

    Ramona Weinrich

    2015-01-01

    Full Text Available Many people view animal welfare standards in the agricultural industry as critical and some consumers would prefer to buy high welfare meat. In order to successfully introduce high welfare meat products onto the market, some important marketing decisions must be made. Due to limited shelf space in retail outlets, niche products like high welfare meat cannot be placed both at the self-service counter and at the service counter. In order to analyze where to place it best an online survey of 642 German consumers was conducted. By means of factor and cluster analyses, consumers’ animal welfare attitudes and their preference for a point of purchase were combined. The different target groups were joint using cross tabulation analysis. The results reveal that consumers in the target group show a more positive attitude to the service counter.

  18. Tracing the Source of Borneo's Cempaka Diamond Deposit

    Science.gov (United States)

    White, L. T.; Graham, I.; Armstrong, R. A.; Hall, R.

    2014-12-01

    Several gem quality diamond deposits are found in paleo-alluvial deposits across Borneo. The source of the diamonds and their origin are enigmatic. They could have formed in Borneo and be derived from local sources, or they could be related to diamond deposits in NW Australia, and carried with the Southwest Borneo Block after it rifted from Australia in the Late Jurassic. We collected U-Pb isotopic data from detrital zircons from the Cempaka alluvial diamond deposit in southeast Borneo. Two thirds of the zircons that were dated crystallized between 75 Ma and 110 Ma. The other third are Triassic or older (223 Ma, 314-319 Ma, 353-367 Ma, 402-414 Ma, 474 Ma, 521 Ma, 549 Ma, 1135-1176 Ma, 1535 Ma, 2716 Ma). All of the Cretaceous zircons are angular, euhedral grains with minor evidence of mechanical abrasion. Considering their age and morphology they were likely derived from the nearby Schwaner Granites. The Triassic and older grains are rounded to semi-rounded and were likely derived from Australia before Borneo rifted from Gondwana. Some of the zircons have ages that resemble those of the Merlin and Argyle diamond deposits of Australia. The diamonds themselves have delicate resorption features and overgrowths that would potentially be destroyed with prolonged transport. Geochemical data collected from the diamonds implies they were associated with lamproite intrusions. Deep seismic lines and zircons from igneous rocks suggest SE Borneo, the East Java Sea and East Java are largely underlain by thick lithosphere rifted from NW Australia. Based on several lines of evidence, we propose that diamond-bearing lamproites intruded before rifting of SW Borneo from Australia, or after collision with Sundaland of SW Borneo and the East Java-West Sulawesi Blocks during the Cretaceous. Exposure of the source after the Late Cretaceous led to diamond accumulation in river systems that flowed from the Schwaner Mountains.

  19. Counter-Narratives and the Unrehearsed Stories Counter-Terrorists Unwittingly Produce

    Directory of Open Access Journals (Sweden)

    Beatrice de Graaf

    2010-11-01

    Full Text Available Governments produce both deliberate and involuntary (and less conscious narratives when countering terrorism. The thesis of this article is that such unintended messages can be much more powerful and consequential than is realized; in fact, they can completely contradict the intended official 'counter-narrative'. To substantiate this hypothesis, the author looks at the experience of the German Federal Republic in the 1970s and beyond when state and society were confronted with the Red Army Faction (RAF and similar left-wing "revolutionaries" like those of the 2nd of June Movement or the Red Zora.

  20. Benzene oxidation at diamond electrodes: comparison of microcrystalline and nanocrystalline diamonds.

    Science.gov (United States)

    Pleskov, Yu V; Krotova, M D; Elkin, V V; Varnin, V P; Teremetskaya, I G; Saveliev, A V; Ralchenko, V G

    2012-08-27

    A comparative study of benzene oxidation at boron-doped diamond (BDD) and nitrogenated nanocrystalline diamond (NCD) anodes in 0.5 M K(2)SO(4) aqueous solution is conducted by using cyclic voltammetry and electrochemical impedance spectroscopy. It is shown by measurements of differential capacitance and anodic current that during the benzene oxidation at the BDD electrode, adsorption of a reaction intermediate occurs, which partially blocks the electrode surface and lowers the anodic current. At the NCD electrode, benzene is oxidized concurrently with oxygen evolution, a (quinoid) intermediate being adsorbed at the electrode. The adsorption and the electrode surface blocking are reflected in the impedance-frequency and impedance-potential complex-plane plots. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.