National Library of Energy BETA

Sample records for zr hf rf

  1. Ternary ceramic alloys of Zr-Ce-Hf oxides

    DOE Patents [OSTI]

    Becher, P.F.; Funkenbusch, E.F.

    1990-11-20

    A ternary ceramic alloy is described which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce[sub x]Hf[sub y]Zr[sub 1[minus]x[minus]y]O[sub 2], is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites. 1 fig.

  2. Zr-Hf separation based on a molten salt/metal

    E-Print Network [OSTI]

    Langendoen, Koen

    Zr-Hf separation based on a molten salt/metal equilibrium )URP ROGIDVKLRQHG Ã?DVKEXOEV to newfangled. These involve complicated multistep batch processes. This new purification method is based on molten salt to raw zirconium and hafnium metal, so a molten metal stream can be achieved and tin chloride salts

  3. Ternary ceramic alloys of ZR-CE-HF oxides

    DOE Patents [OSTI]

    Becher, Paul F. (Oak Ridge, TN); Funkenbusch, Eric F. (White Bear Lake, MN)

    1990-01-01

    A ternary ceramic alloy which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce.sub.x Hf.sub.y Zn.sub.1-x-y O.sub.2, is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites.

  4. Effects of ZrO{sub 2} doping on HfO{sub 2} resistive switching memory characteristics

    SciTech Connect (OSTI)

    Ryu, Seung Wook; Kwac, Jungsuk; Nishi, Yoshio [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Cho, Seongjae, E-mail: felixcho@gachon.ac.kr [Department of Electronic Engineering and New Technology Component and Material Research Center (NCMRC), Gachon University, Seongnam-si, Gyeonggi-do 461-741 (Korea, Republic of); Park, Joonsuk [Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States); Kim, Hyeong Joon [Department of Materials Science and Engineering and Inter-university Semiconductor Research Center (ISRC), Seoul National University, Seoul 151-744 (Korea, Republic of)

    2014-08-18

    A resistive switching (RS) random access memory device with ZrO{sub 2}-doped HfO{sub 2} exhibits better RS performance than that with pure HfO{sub 2}. In particular, I{sub res}, V{sub res}, and V{sub set} are reduced by approximately 58%, 38%, and 39%, respectively, when HfO{sub 2} is doped with ZrO{sub 2} (9 at.?%). In addition, the ZrO{sub 2} doping in HfO{sub 2} makes the distribution of most parameters steeper. Transmission electron microscopy (TEM) analysis reveals that the deposited zirconium-doped hafnium oxide (HZO) (9 at.?%) is polycrystalline. Elemental mapping results by scanning TEM–energy dispersive spectroscopy also prove that ZrO{sub 2} is uniformly distributed in the HZO (9 at.?%) film. The possible mechanism for the improvement in the RS characteristics is also suggested on the basis of the X-ray photoelectron spectroscopy results and filamentary RS mechanism. These results suggest that the ZrO{sub 2} doping into HfO{sub 2} likely not only will reduce power consumption but also will improve cyclic endurance by controlling the nonstoichiometric phase.

  5. Mechanistic investigation of vinylic carbonfluorine bond activation of perfluorinated cycloalkenes using Cp*2ZrH2 and Cp*2ZrHF

    E-Print Network [OSTI]

    Jones, William D.

    using Cp*2ZrH2 and Cp*2ZrHF Bradley M. Kraft a , Eric Clot b , Odile Eisenstein b , William W behaves similarly [4]. In contrast, Cp*Rh(PMe3)H2 reacts with C6F6 by way of an SNAr2 attack by its conjugate base to give Cp*Rh(PMe3)(C6F5)H and fluoride ion, resulting in an autocatalytic reaction [5]. Cp

  6. Continuous production of granular or powder Ti, Zr and Hf or their alloy products

    DOE Patents [OSTI]

    White, Jack C. (Albany, OR); Oden, Laurance L. (Albany, OR)

    1993-01-01

    A continuous process for producing a granular metal selected from the group consisting of Ti, Zr or Hf under conditions that provide orderly growth of the metal free of halide inclusions comprising: a) dissolving a reducing metal selected from the group consisting of Na, Mg, Li or K in their respective halide salts to produce a reducing molten salt stream; b) preparing a second molten salt stream containing the halide salt of Ti, Zr or Hf; c) mixing and reacting the two molten streams of steps a) and b) in a continuous stirred tank reactor; d) wherein steps a) through c) are conducted at a temperature range of from about 800.degree. C. to about 1100.degree. C. so that a weight percent of equilibrium solubility of the reducing metal in its respective halide salt varies from about 1.6 weight percent at about 900.degree. C. to about 14.4 weight percent at about 1062.degree. C.; and wherein a range of concentration of the halide salt of Ti, Zn or Hf in molten halides of Na, Mg, Li or K is from about 1 to about 5 times the concentration of Na, Mg, Li or K; e) placing the reacted molten stream from step c) in a solid-liquid separator to recover an impure granular metal product by decantation, centrifugation, or filtration; and f) removing residual halide salt impurity by vacuum evaporator or inert gas sweep at temperatures from about 850.degree. C. to 1000.degree. C. or cooling the impure granular metal product to ambient temperature and water leaching off the residual metal halide salt.

  7. Microstructural Characterization and Shape Memory Response of Ni-Rich NiTiHf and NiTiZr High Temperature Shape Memory Alloys 

    E-Print Network [OSTI]

    Evirgen, Alper

    2014-08-14

    NiTiHf and NiTiZr high temperature shape memory alloys (HTSMAs) have drawn a great deal of attention as cheaper alternatives to Pt, Pd and Au alloyed NiTi-based HTSMAs while NiTiZr alloys also providing at least 20% weight reduction then its Ni...

  8. Hole Trapping at Surfaces of m?ZrO2 and m?HfO2 Nanocrystals

    SciTech Connect (OSTI)

    Wolf, Matthew J.; Mckenna, Keith P.; Shlyuger, Alexander L.

    2012-12-03

    We investigate hole trapping at the most prevalent facets of monoclinic zirconia (m-ZrO2) and hafnia (m-HfO2) nanocrystals using first-principles methods. The localization of holes at surface oxygen ions is more favorable than in the bulk crystal by up to ?1 eV. This is caused mainly by the reduction of the absolute value of the electrostatic potential at the surface ions with respect to the bulk and by the significant surface distortion caused by the hole localization. The mobility of holes at surfaces is much lower than that found in the bulk and is fairly isotropic. Unlike in cubic oxides, such as MgO and CaO, we do not find a significant driving force for preferential trapping of holes at steps on the m-ZrO2 surface. These fundamental results are relevant to mechanisms of water oxidation, photocatalysis, contact charging, and photodesorption.

  9. Electron-stimulated desorption from polished and vacuum fired 316LN stainless steel coated with Ti-Zr-Hf-V

    SciTech Connect (OSTI)

    Malyshev, Oleg B. Valizadeh, Reza; Hogan, Benjamin T.; Hannah, Adrian N.

    2014-11-01

    In this study, two identical 316LN stainless steel tubular samples, which had previously been polished and vacuum-fired and then used for the electron-stimulated desorption (ESD) experiments, were coated with Ti-Zr-Hf-V with different morphologies: columnar and dense. ESD measurement results after nonevaporable getter (NEG) activation to 150, 180, 250, and 350?°C indicated that the values for the ESD yields are significantly (2–20 times) lower than the data from our previous study with similar coatings on nonvacuum-fired samples. Based on these results, the lowest pressure and best long-term performance in particle accelerators will be achieved with a vacuum-fired vacuum chamber coated with dense Ti-Zr-Hf-V coating activated at 180?°C. This is likely due to the following facts: after NEG activation, the hydrogen concentration inside the NEG was lower than in the bulk stainless steel substrate; the NEG coating created a barrier for gas diffusion from the sample bulk to vacuum; the dense NEG coating performed better as a barrier than the columnar NEG coating.

  10. Density functional theory study of first-layer adsorption of ZrO2 and HfO2 on Ge(100)

    E-Print Network [OSTI]

    Kummel, Andrew C.

    in this manuscript), usually grown by atomic layer deposition (ALD). These oxides, under normal Ge process- ingDensity functional theory study of first-layer adsorption of ZrO2 and HfO2 on Ge(100) T.J. Grassman

  11. 13.21 Geochemistry of the Rare-Earth Element, Nb, Ta, Hf, and Zr Deposits RL Linnen, University of Western Ontario, London, ON, Canada

    E-Print Network [OSTI]

    Chakhmouradian, Anton

    13.21 Geochemistry of the Rare-Earth Element, Nb, Ta, Hf, and Zr Deposits RL Linnen, University of rare metals in natural fluids 551 13.21.2.2.2 Aqueous complexation and mineral solubility 552 13 Acknowledgments 564 References 564 13.21.1 Introduction Rare-element mineral deposits, also called rare-metal

  12. Hydrolysis of ZrCl4 and HfCl4: The Initial Steps in the High-Temperature Oxidation of Metal Chlorides to Produce ZrO2 and HfO2

    SciTech Connect (OSTI)

    Fang, Zongtang; Dixon, David A.

    2013-03-08

    The gas-phase hydrolysis of MCl4 (M = Zr, Hf) to produce the initial particles on the way to zirconia and hafnia nanoparticles has been studied with electronic structure theory. The potential energy surfaces, the themochemistry of the reaction species, and the reaction paths for the initial steps of MCl4 reacting with H2O have been calculated. The hydrolysis of MCl4 at higher temperatures begins with the formation of oxychlorohydroxides followed by the elimination of HCl instead of the direct production of MOCl2 and HCl or MO2 and HCl due to the substantial endothermicities associated with the formation of gas-phase MO2. The structural properties and heats of formation of the reactants and products are consistent with the available experimental results. A number of metal oxychlorides (oxychlorohydroxides) intermediate clusters have been studied to assess their role in the production of MO2 nanoparticles. The calculated clustering reaction energies of those intermediates are highly exothermic, so they could be readily formed in the hydrolysis process. These intermediate clusters can be formed exothermically from metal oxychlorohydroxides by the elimination of one HCl or H2O molecule. Our calculations show that the mechanisms leading to the formation of MO2 nanoparticles are complicated and are accompanied by the potential production of a wide range of intermediates, as found for the production of TiO2 particles from the high-temperature oxidation of TiCl4.

  13. Manipulation of electronic and magnetic properties of M{sub 2}C (M = Hf, Nb, Sc, Ta, Ti, V, Zr) monolayer by applying mechanical strains

    SciTech Connect (OSTI)

    Zhao, Shijun; Kang, Wei; Xue, Jianming

    2014-03-31

    Tuning the electronic and magnetic properties of a material through strain engineering is an effective strategy to enhance the performance of electronic and spintronic devices. In this paper, first-principles calculations based on density functional theory are carried out to investigate the electronic and magnetic properties of M{sub 2}C(M?=?Hf, Nb, Sc, Ta, Ti, V, Zr, known as MXenes) subjected to biaxial symmetric mechanical strains. At the strain-free state, all these MXenes exhibit no spontaneous magnetism except for Ti{sub 2}C and Zr{sub 2}C which show a magnetic moment of 1.92 and 1.25??{sub B}/unit, respectively. As the tensile strain increases, the magnetic moments of MXenes are greatly enhanced and a transition from nonmagnetism to ferromagnetism is observed for those nonmagnetic MXenes at zero strains. The most distinct transition is found in Hf{sub 2}C, in which the magnetic moment is elevated to 1.5??{sub B}/unit at a strain of 1.80%. We further show that the magnetic properties of Hf{sub 2}C are attributed to the band shift mainly composed of Hf(5d) states.

  14. First-principles studies of structural stabilities and enthalpies of formation of refractory intermetallics: TM and TM3 (T = Ti, Zr, Hf; M = Ru, Rh, Pd, Os, Ir, Pt)

    SciTech Connect (OSTI)

    Xing, Weiwei; Chen, X.; Li, Dianzhong; Li, Y. Y.; Fu, Chong Long; Meschel, S.

    2012-01-01

    Using first-principles local density functional approach, we have calculated the ground-state structural phase stabilities and enthalpies of formation of thirty-six binary transition-metal refractory TM and TM3 compounds formed by Group IV elements T (T = Ti, Zr, Hf) and platinum group elements M (M = Ru, Rh, Pd, Os, Ir, Pt) . We compared our results with the available experimental data and found good agreement between theory and experiment in both the trends of structural stabilities and the magnitudes of formation enthalpies. Moreover, based on our calculated results, an empirical relationship between cohesive energies ( E) and melting temperatures (Tm) was derived as Tm = 0.0292 E/kB (where kB is the Boltzmann constant) for both TM and TM3 compounds.

  15. Determining Relative f and d Orbital Contributions to M?Cl Covalency in MCl62– (M = Ti, Zr, Hf, U) and UOCl5 Using Cl K-Edge X-ray Absorption Spectroscopy and Time-Dependent Density Functional Theory

    SciTech Connect (OSTI)

    Minasian, Stefan G.; Keith, Jason M.; Batista, Enrique R.; Boland, Kevin S.; Clark, David L.; Conradson, Steven D.; Kozimor, Stosh A.; Martin, Richard L.; Schwarz, Daniel E.; Shuh, David K.; Wagner, Gregory L.; Wilkerson, Marianne P.; Wolfsberg, Laura E.; Yang, Ping

    2012-03-09

    Chlorine K-edge X-ray absorption spectroscopy (XAS) and ground-state and time-dependent hybrid density functional theory (DFT) were used to probe electronic structure for O{sub h}-MCl{sub 6}{sup 2-}(M = Ti, Zr, Hf, U) and C{sub 4v}-UOCl{sub 5}{sup -}, and to determine the relative contributions of valence 3d, 4d, 5d, 6d, and 5f orbitals in M-Cl bonding. Spectral interpretations were guided by time-dependent DFT calculated transition energies and oscillator strengths, which agree well with the experimental XAS spectra. The data provide new spectroscopic evidence for the involvement of both 5f and 6d orbitals in actinide-ligand bonding in UCl{sub 6}{sup 2-}. For the MCl{sub 6}{sup 2-}, where transitions into d orbitals of t{sub 2g} symmetry are spectroscopically resolved for all four complexes, the experimentally determined Cl 3p character per M-Cl bond increases from 8.3(4)% (TiCl{sub 6}{sup 2-}) to 10.3(5)% (ZrCl{sub 6}{sup 2-}), 12(1)% (HfCl{sub 6}{sup 2-}), and 26 18(1)% (UCl{sub 6}{sup 2-}). Chlorine K-edge XAS spectra of UOCl{sub 5}{sup -} provide additional insights into the transition assignments by 27 lowering the symmetry to C{sub 4v}, where five pre-edge transitions into both 5f and 6d orbitals are observed. For UCl{sub 6}{sup 2-}, the XAS data 28 suggest that orbital mixing associated with the U 5f orbitals is considerably lower than that of the U 6d orbitals. For both UCl{sub 6}{sup 2-}29 and UOCl{sub 5}{sup -}, the ground-state DFT calculations predict a larger 5f contribution to bonding than is determined experimentally. 30 These findings are discussed in the context of conventional theories of covalent bonding for d- and f-block metal complexes.

  16. Elastic properties of perovskite ATiO{sub 3} (A?=?Be, Mg, Ca, Sr, and Ba) and PbBO{sub 3} (B?=?Ti, Zr, and Hf): First principles calculations

    SciTech Connect (OSTI)

    Pandech, Narasak; Limpijumnong, Sukit; Sarasamak, Kanoknan

    2015-05-07

    The mechanical properties of perovskite oxides depend on two metal oxide lattices that are intercalated. This provides an opportunity for separate tuning of hardness, Poisson's ratio (transverse expansion in response to the compression), and shear strength. The elastic constants of series of perovskite oxides were studied by first principles approach. Both A-site and B-site cations were systematically varied in order to see their effects on the elastic parameters. To study the effects of A-site cations, we studied the elastic properties of perovskite ATiO{sub 3} for A being Be, Mg, Ca, Sr, or Ba, one at a time. Similarly, for B-site cations, we studied the elastic properties of PbBO{sub 3} for B being Ti, Zr, or Hf, one at a time. The density functional first principles calculations with local density approximation (LDA) and generalized gradient approximation (GGA) were employed. It is found that the maximum C{sub 11} elastic constant is achieved when the atomic size of the cations at A-site and B-site are comparable. We also found that C{sub 12} elastic constant is sensitive to B-site cations while C{sub 44} elastic constant is more sensitive to A-site cations. Details and explanations for such dependencies are discussed.

  17. Mechanism of Vinylic and Allylic Carbon-Fluorine Bond Activation of Non-Perfluorinated Olefins Using Cp*2ZrH2

    E-Print Network [OSTI]

    Jones, William D.

    Using Cp*2ZrH2 Bradley M. Kraft and William D. Jones* Contribution from the Department of Chemistry, UniVersity of Rochester, Rochester, New York 14627 Received November 16, 2001 Abstract: Cp*2ZrH2 (1) (CpH10) to afford Cp*2ZrHF (2) and hydrodefluorinated products. Experimental evidence suggests

  18. Characterizing HfXZr1-XO2 by EXAFS: Relationship Between Bulk and Surface Composition, and Impact on Catalytic Selectivity for Alcohol Conversion

    SciTech Connect (OSTI)

    Jacobs, G.; Milling, M; Ji, Y; Patterson, P; Sparks, D; Davis, B

    2009-01-01

    A series of mixed Hf{sub X}Zr{sub 1-X}O{sub 2} oxide catalysts was prepared according to a recipe that yields the monoclinic structure. The samples were examined by EXAFS spectroscopy at the Zr K and Hf L{sub III} edges. A fitting model was used that simultaneously fits data from both edges, and makes use of an interdependent mixing parameter X mix to take into account substitution of the complementary atom in the nearest metal-metal shell. For XPS analysis, Scofield factors were applied to estimate the relative atomic surface concentrations of Zr and Hf. EXAFS results suggested that a solid bulk solution was formed over a wide range of X for Hf{sub X}Zr{sub 1-X}O{sub 2} binary oxides, and that the relative ratio was retained in the surface shell (i.e., including some subsurface layers by XPS) and the surface (e.g., by ISS). The increase in selectivity for the 1-alkene from dehydration of alcohols at high Zr content does not correlate smoothly with the tuned relative atomic concentration of Hf to Zr. The step change at high Zr content appears to be due to other indirect factors (e.g., surface defects, oxygen vacancies).

  19. Recycler barrier RF buckets

    SciTech Connect (OSTI)

    Bhat, C.M.; /Fermilab

    2011-03-01

    The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  20. Decay Studies of the New Isotopes Hf-162,hf-163 

    E-Print Network [OSTI]

    Schrewe, U. J.; Hagberg, E.; Schmeing, H.; Hardy, John C.; Koslowsky, V. T.; Sharma, KS; Clifford, E. T. H.

    1982-01-01

    ) considering interaction between a hydraulic fracture (HF) and a pre-existing NF, has been investigated comprehensively using a two dimensional Displacement Discontinuity Method (DDM) Model in this thesis. The rock is first considered as an elastic impermeable...

  1. Rf Feedback free electron laser

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

    1981-01-01

    A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.

  2. Shielded RF Lattice Chris Rogers,

    E-Print Network [OSTI]

    McDonald, Kirk

    Shielded RF Lattice Chris Rogers, Accelerator Science and Technology Centre (ASTeC), Rutherford Appleton Laboratory #12;Shielded RF Status Shielded RF Lattice was developed until ~ April 2010 April make the same decision for RDR Time to dust the design off #12;Shielded RF - Reminder Increase cell

  3. Rf2a and rf2b transcription factors

    DOE Patents [OSTI]

    Beachy, Roger N. (St. Louis, MO); Petruccelli, Silvana (La Plata, AR); Dai, Shunhong (St. Louis, MO)

    2007-10-02

    A method of activating the rice tungro bacilliform virus (RTBV) promoter in vivo is disclosed. The RTBV promoter is activated by exposure to at least one protein selected from the group consisting of Rf2a and Rf2b.

  4. RF test bench automation Description

    E-Print Network [OSTI]

    Dobigeon, Nicolas

    RF test bench automation Description: Callisto would like to implement automated RF test bench. Three RF test benches have to be studied and automated: LNA noise temperature test bench LNA gain phase of the test benches and an implementation of the automation phase. Tasks: Noise temperature

  5. Racetrack microtron rf system

    SciTech Connect (OSTI)

    Tallerico, P.J.; Keffeler, D.R.

    1985-01-01

    The rf system for the National Bureau of Standards (NBS)/Los Alamos cw racetrack microtron is described. The low-power portion consists of five 75-W amplifers that drive two input ports in each of two chopper deflection cavities and one port in the prebuncher cavity. A single 500-kW klystron drives four separate 2380-MHz cavity sections: the two main accelerator sections, a capture section, and a preaccelerator section. The phases and amplitudes in all cavities are controlled by electronic or electromechanical controls. The 1-MW klystron power supply and crowbar system were purchased as a unit; several modifications are described that improve power-supply performance. The entire rf system has been tested and shipped to the NBS, and the chopper-buncher system has been operated with beam at the NBS. 5 refs., 2 figs.

  6. Collisional quenching of highly rotationally excited HF

    E-Print Network [OSTI]

    Yang, Benhui; Forrey, R C; Stancil, P C; Balakrishnan, N

    2015-01-01

    Collisional excitation rate coefficients play an important role in the dynamics of energy transfer in the interstellar medium. In particular, accurate rotational excitation rates are needed to interpret microwave and infrared observations of the interstellar gas for nonlocal thermodynamic equilibrium line formation. Theoretical cross sections and rate coefficients for collisional deexcitation of rotationally excited HF in the vibrational ground state are reported. The quantum-mechanical close-coupling approach implemented in the nonreactive scattering code MOLSCAT was applied in the cross section and rate coefficient calculations on an accurate 2D HF-He potential energy surface. Estimates of rate coefficients for H and H$_2$ colliders were obtained from the HF-He collisional data with a reduced-potential scaling approach. The calculation of state-to-state rotational quenching cross sections for HF due to He with initial rotational levels up to $j=20$ were performed for kinetic energies from 10$^{-5}$ to 15000...

  7. Ion source with external RF antenna

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Ji, Qing; Wilde, Stephen

    2005-12-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source.

  8. RF power generation

    E-Print Network [OSTI]

    Carter, R G

    2011-01-01

    This paper reviews the main types of r.f. power amplifiers which are, or may be, used for particle accelerators. It covers solid-state devices, tetrodes, inductive output tubes, klystrons, magnetrons, and gyrotrons with power outputs greater than 10 kW c.w. or 100 kW pulsed at frequencies from 50 MHz to 30 GHz. Factors affecting the satisfactory operation of amplifiers include cooling, matching and protection circuits are discussed. The paper concludes with a summary of the state of the art for the different technologies.

  9. Metal-Organic Frameworks Based on Previously Unknown Zr8/Hf Cubic

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you notHeatMaRIEdioxide capture | Center for Gas SeparationsRelevant

  10. Solid-State Coexistance of (Zr12) and (Zr6) Zirconium Oxocarboxylate Clusters

    SciTech Connect (OSTI)

    Malaestean, Lurie [RWTH Aachen University; Alici, Meliha Kutluca [RWTH Aachen University; Besson, Claire [RWTH Aachen University; Ellern, Arkady [Ames Laboratory; Kogerler, Paul [RWTH Aachen University

    2013-10-30

    Ligand metathesis, Co(II) coordination, and partial condensation reactions of an archetypal {Zr6} zirconium oxocarboxylate cluster result in the first example of the coexistence of the distinct zirconium oxide frameworks {Zr6O8} and {Zr12O22}. Even minor modifications to the reaction conditions push this apparent equilibrium towards the {Zr6O8}-based product.

  11. Solid-state coexistence of {Zr12} and {Zr6} zirconium oxocarboxylate clusters

    SciTech Connect (OSTI)

    Malaestean, Iurie L. [RWTH Aachen University; Alici, Meliha Kutluca [RWTH Aachen University; Besson, Claire [RWTH Aachen University; Ellern, Arkady [Ames Laboratory; Kogerler, Paul [RWTH Aachen University

    2013-10-30

    Ligand metathesis, Co(II) coordination, and partial condensation reactions of an archetypal {Zr6} zirconium oxocarboxylate cluster result in the first example of the coexistence of the distinct zirconium oxide frameworks {Zr6O8} and {Zr12O22}. Even minor modifications to the reaction conditions push this apparent equilibrium towards the {Zr6O8}-based product.

  12. Transverse spin freezing in Ruthenium-doped a Fe 90 Zr 10 Physics Department and Centre for the Physics of Materials, McGill University, 3600 University Street, Montreal, Quebec

    E-Print Network [OSTI]

    Ryan, Dominic

    Transverse spin freezing in Ruthenium-doped a Fe 90 Zr 10 D.H. Ryan Physics Department and Centre , followed by transverse spin freezing at Txy . Comparison with earlier Mossbauer data shows that the break in B hf (T) is indeed due to transverse spin freezing, and that both Mossbauer spectroscopy and #22;SR

  13. Acidizing of Sandstone Reservoirs Using HF and Organic Acids 

    E-Print Network [OSTI]

    Yang, Fei

    2012-10-19

    Mud acid, which is composed of HCl and HF, is commonly used to remove the formation damage in sandstone reservoirs. However, many problems are associated with HCl, especially at high temperatures. Formic-HF acids have served as an alternative...

  14. WAVE-DRIVEN SURFACE FROM HF RADAR

    E-Print Network [OSTI]

    Miami, University of

    FEATURE INTERNAL CURRENTS WAVE-DRIVEN SURFACE FROM HF RADAR By Lynn K. Shay Observations from recent experiments · . . have revealed internal wave signatures. SURFACE CURRENTobservations from high oscillations are within the inter- nal wave continuum from the buoyancy to the in- ertial frequencies

  15. RF breakdown experiments at SLAC

    SciTech Connect (OSTI)

    Laurent, L. [University of California Davis, Davis, California 95616 (United States); Vlieks, A.; Pearson, C.; Caryotakis, G.; Luhmann, N.C. [Stanford Linear Accelerator Center, Menlo Park, California 94025 (United States)

    1999-05-01

    RF breakdown is a critical issue in the conditioning of klystrons, accelerator sections, and rf components for the next linear collider (NLC), as well as other high gradient accelerators and high power microwave sources. SLAC is conducting a series of experiments using an X-band traveling wave ring to characterize the processes and trigger mechanisms associated with rf breakdown. The goal of the research is to identify materials, processes, and manufacturing methods that will increase the breakdown threshold and minimize the time required for conditioning. {copyright} {ital 1999 American Institute of Physics.}

  16. Numerical prediction of the thermodynamic properties of ternary Al-Ni-Hf alloys

    SciTech Connect (OSTI)

    Romanowska, Jolanta; Kotowski, S?awomir; Zagula-Yavorska, Maryana

    2014-10-06

    Thermodynamic properties of ternary Al-Hf-Ni system, such as {sup ex}G, ?{sub Al}, ?{sub Ni} and ?{sub Zr} at 1373K were predicted on the basis of thermodynamic properties of binary systems included in the investigated ternary system. The idea of predicting {sup ex}G values was regarded as the calculation of excess Gibbs energy values inside a certain area (a Gibbs triangle) unless all boundary conditions, that is values of {sup ex}G on all legs of the triangle are known. {sup ex}G and L{sub ijk} ternary interaction parameters in the Muggianu extension of the Redlich-Kister formalism are calculated numerically using Wolfram Mathematica 9 software.

  17. Unbalanced field RF electron gun

    DOE Patents [OSTI]

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  18. Intelligent Radio Frequency (RF) Monitoring 

    E-Print Network [OSTI]

    Kimbrough, B.

    2010-01-01

    ? Regulatory fines Location 8 ?Expect many enjoyable experiences!? David M. Armstrong Continuous RF Monitoring RELIEF VALVE MONITORING The solution?? 9 ?Expect many enjoyable experiences!? David M. Armstrong Continuous RF Monitoring TEMPERATURE...?Armstrong? WiHART?Device Non?Armstrong? WiHART?Device Non?Armstrong? WiHART?Device Open Mesh Wireless Structure STEAM TRAP MONITORING RELIEF VALVE MONITORING TEMPERATURE MONITORING GATEWAY 14 ?Expect many enjoyable experiences!? David M. Armstrong...

  19. Phase modulation in RF tag

    DOE Patents [OSTI]

    Carrender, Curtis Lee; Gilbert, Ronald W.

    2007-02-20

    A radio frequency (RF) communication system employs phase-modulated backscatter signals for RF communication from an RF tag to an interrogator. The interrogator transmits a continuous wave interrogation signal to the RF tag, which based on an information code stored in a memory, phase-modulates the interrogation signal to produce a backscatter response signal that is transmitted back to the interrogator. A phase modulator structure in the RF tag may include a switch coupled between an antenna and a quarter-wavelength stub; and a driver coupled between the memory and a control terminal of the switch. The driver is structured to produce a modulating signal corresponding to the information code, the modulating signal alternately opening and closing the switch to respectively decrease and increase the transmission path taken by the interrogation signal and thereby modulate the phase of the response signal. Alternatively, the phase modulator may include a diode coupled between the antenna and driver. The modulating signal from the driver modulates the capacitance of the diode, which modulates the phase of the response signal reflected by the diode and antenna.

  20. Ion bombardment in RF photoguns

    SciTech Connect (OSTI)

    Pozdeyev,E.; Kayran, D.; Litvinenko, V. N.

    2009-05-04

    A linac-ring eRHIC design requires a high-intensity CW source of polarized electrons. An SRF gun is viable option that can deliver the required beam. Numerical simulations presented elsewhere have shown that ion bombardment can occur in an RF gun, possibly limiting lifetime of a NEA GaAs cathode. In this paper, we analytically solve the equations of motion of ions in an RF gun using the ponderomotive potential of the Rf field. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper discusses possible mitigation techniques that can reduce the rate of ion bombardment.

  1. Cryogenic vacuumm RF feedthrough device

    DOE Patents [OSTI]

    Wu, Genfa (Yorktown, VA); Phillips, Harry Lawrence (Hayes, VA)

    2008-12-30

    A cryogenic vacuum rf feedthrough device comprising: 1) a probe for insertion into a particle beam; 2) a coaxial cable comprising an inner conductor and an outer conductor, a dielectric/insulating layer surrounding the inner conductor, the latter being connected to the probe for the transmission of higher mode rf energy from the probe; and 3) a high thermal conductivity stub attached to the coaxial dielectric about and in thermal contact with the inner conductor which high thermal conductivity stub transmits heat generated in the vicinity of the probe efficiently and radially from the area of the probe and inner conductor all while maintaining useful rf transmission line characteristics between the inner and outer coaxial conductors.

  2. Klystron equalization for RF feedback

    SciTech Connect (OSTI)

    Corredoura, P.

    1993-01-01

    The next generation of colliding beam storage rings support higher luminosities by significantly increasing the number of bunches and decreasing the spacing between respective bunches. The heavy beam loading requires large RF cavity detuning which drives several lower coupled bunch modes very strongly. One technique which has proven to be very successful in reducing the coupled bunch mode driving impedance is RF feedback around the klystron-cavity combination. The gain and bandwidth of the feedback loop is limited by the group delay around the feedback loop. Existing klystrons on the world market have not been optimized for this application and contribute a large portion of the total loop group delay. This paper describes a technique to reduce klystron group delay by adding an equalizing filter to the klystron RF drive. Such a filter was built and tested on a 500 kill klystron as part of the on going PEP-II R&D effort here at SLAC.

  3. Klystron equalization for RF feedback

    SciTech Connect (OSTI)

    Corredoura, P.

    1993-01-01

    The next generation of colliding beam storage rings support higher luminosities by significantly increasing the number of bunches and decreasing the spacing between respective bunches. The heavy beam loading requires large RF cavity detuning which drives several lower coupled bunch modes very strongly. One technique which has proven to be very successful in reducing the coupled bunch mode driving impedance is RF feedback around the klystron-cavity combination. The gain and bandwidth of the feedback loop is limited by the group delay around the feedback loop. Existing klystrons on the world market have not been optimized for this application and contribute a large portion of the total loop group delay. This paper describes a technique to reduce klystron group delay by adding an equalizing filter to the klystron RF drive. Such a filter was built and tested on a 500 kill klystron as part of the on going PEP-II R D effort here at SLAC.

  4. Negative ion source with external RF antenna

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Hahto, Sami K.; Hahto, Sari T.

    2007-02-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source. A converter can be included in the ion source to produce negative ions.

  5. Note on RF Photo-Cathode Gun

    E-Print Network [OSTI]

    Kim, Kwang-Je

    2010-01-01

    Emittances in Laser-Driven RF Guns", Proc. 1988 Linear Acc.Palmer, "Preliminary Study of Gun Emittance Correction", BNLLaser-Driven RF Electron Guns", Nuc1. ln stt. Meth. , A275,

  6. High-Power Rf Load

    DOE Patents [OSTI]

    Tantawi, Sami G. (San Mateo, CA); Vlieks, Arnold E. (Livermore, CA)

    1998-09-01

    A compact high-power RF load comprises a series of very low Q resonators, or chokes [16], in a circular waveguide [10]. The sequence of chokes absorb the RF power gradually in a short distance while keeping the bandwidth relatively wide. A polarizer [12] at the input end of the load is provided to convert incoming TE.sub.10 mode signals to circularly polarized TE.sub.11 mode signals. Because the load operates in the circularly polarized mode, the energy is uniformly and efficiently absorbed and the load is more compact than a rectangular load. Using these techniques, a load having a bandwidth of 500 MHz can be produced with an average power dissipation level of 1.5 kW at X-band, and a peak power dissipation of 100 MW. The load can be made from common lossy materials, such as stainless steel, and is less than 15 cm in length. These techniques can also produce loads for use as an alternative to ordinary waveguide loads in small and medium RF accelerators, in radar systems, and in other microwave applications. The design is easily scalable to other RF frequencies and adaptable to the use of other lossy materials.

  7. The LHC Low Level RF

    E-Print Network [OSTI]

    Baudrenghien, Philippe; Molendijk, John Cornelis; Olsen, Ragnar; Rohlev, Anton; Rossi, Vittorio; Stellfeld, Donat; Valuch, Daniel; Wehrle, Urs

    2006-01-01

    The LHC RF consists of eight 400 MHz superconducting cavities per ring, with each cavity independently powered by a 300 kW klystron, via a circulator. The challenge for the Low Level is to cope with very high beam current (more than 1 A RF component) and achieve excellent beam lifetime (emittance growth time in excess of 25 hours). Each cavity has an associated Cavity Controller rack consisting of two VME crates which implement high gain RF Feedback, a Tuner Loop with a new algorithm, a Klystron Ripple Loop and a Conditioning system. In addition each ring has a Beam Control system (four VME crates) which includes a Frequency Program, Phase Loop, Radial Loop and Synchronization Loop. A Longitudinal Damper (dipole and quadrupole mode) acting via the 400 MHz cavities is included to reduce emittance blow-up due to filamentation from phase and energy errors at injection. Finally an RF Synchronization system implements the bunch into bucket transfer from the SPS into each LHC ring. When fully installed in 2007, the...

  8. RF digital-to-analog converter

    DOE Patents [OSTI]

    Conway, Patrick H. (Rancho Palos Verdes, CA); Yu, David U. L. (Rancho Palos Verdes, CA)

    1995-01-01

    A digital-to analogue converter for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration.

  9. RF digital-to-analog converter

    DOE Patents [OSTI]

    Conway, P.H.; Yu, D.U.L.

    1995-02-28

    A digital-to-analog converter is disclosed for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration. 18 figs.

  10. Introduction Final Cooling Channel -High Frequency RF

    E-Print Network [OSTI]

    McDonald, Kirk

    Outline Introduction Final Cooling Channel - High Frequency RF Muon Collider Final Cooling Hisham Sayed February 27, 2014 1 / 10 #12;Outline Introduction Final Cooling Channel - High Frequency RF Table of Contents 1 Introduction 2 Final Cooling Channel - High Frequency RF 2 / 10 #12;Outline Introduction Final

  11. BROADBAND LOW ACTUATIONVOLTAGE RF'MEM SWITCHES

    E-Print Network [OSTI]

    Shen, Shyh-Chiang

    (RF) Microelectromechanical (MEM) switches have been thought of as one of the most attractive devicesBROADBAND LOW ACTUATIONVOLTAGE RF'MEM SWITCHES Shyh-ChiangShen,David Caruth, and Milton Feng of Illinois at Urbana-Champaign,IL61801-2355 ABSTRACT- We demonstrate a sub-lovolts RF MEM switch built

  12. Wind turbine impacts on HF radar ocean surface measurements in

    E-Print Network [OSTI]

    Wyatt, Lucy

    Wind turbine impacts on HF radar ocean surface measurements in Liverpool Bay Alice Robinson School. The characterisation of the wind turbine interference is assessed and the radar cross section estimated. The modulation with wind turbine interference in a HF radar footprint are made. #12;Contents Contents iv List of Tables vii

  13. HYDROGEN FLUORIDE Hydrogen Fluoride (HF) is an extremely

    E-Print Network [OSTI]

    Lance, Veronica P.

    HYDROGEN FLUORIDE Hydrogen Fluoride (HF) is an extremely corrosive clear and colorless liquid BE PROVIDED TO INDIVIDUALS WITH EXPOSURE TO HYDROGEN FLOURIDE www.ehs.columbia.edu/HFPolicy.html HF USE. Because hydrogen fluoride can penetrate natural rubber gloves you must use only neoprene or nitrile gloves

  14. Enthalpy of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys

    SciTech Connect (OSTI)

    Witusiewicz, V.T.; Sommer, F.

    2000-04-01

    Since the Al-Cu-Ni-Zr system is a basis for the production of bulk amorphous materials by rapid solidification techniques from the liquid state, it is of great scientific interest to determine the partial and the integral thermodynamic functions of liquid and undercooled liquid alloys. Such data, as was pointed out previously, are important in order to understand their extremely good glass-forming ability in multicomponent metallic systems as well as for processing improvements. In order to measure the thermodynamic properties of the Al-Cu-Ni-Zr quaternary, it is necessary to have reliable thermochemical data for its constituent canaries and ternaries first. In a series of articles, the authors have reported in detail the thermodynamic properties of liquid Al-Cu, Al-Ni, Cu-Ni, Cu-Zr, Al-Zr, Al-Cu-Ni, and Al-Cu-Zr alloys. This article deals with the direct calorimetric measurements of the partial and the integral enthalpies of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys and the heat capacity of liquid Ni{sub 26}Zr{sub 74}. In a subsequent article, the authors will present similar data for the liquid ternary Al-Ni-Zr and for the liquid quaternary Al-Cu-Ni-Zr alloys.

  15. HfB2 and HfBN hard coatings by chemical vapor deposition S. Jayaraman a,c

    E-Print Network [OSTI]

    Girolami, Gregory S.

    are popular materials for hard and environmental coat- ings [1­16]. Applications include cutting tools, wearHfB2 and Hf­B­N hard coatings by chemical vapor deposition S. Jayaraman a,c , J.E. Gerbi a,c , Y rights reserved. Keywords: Hafnium diboride; Hafnium borohydride; CVD; Hard coating; Nanoindentation

  16. The SPEAR3 RF System

    SciTech Connect (OSTI)

    McIntosh, P.

    2005-01-18

    SPEAR2 was upgraded in 2003, to a new 3rd Generation Light Source (3GLS)-SPEAR3, enabling users to take better advantage of almost 100x higher brightness and flux density over its predecessor. As part of the upgrade, the SPEAR2 RF system has been revamped from its original configuration of one 200 kW klystron feeding a single 358.5 MHz, 5-cell aluminum cavity; to a 1.2 MW klystron feeding four 476.3 MHz, HOM damped copper cavities. The system installation was completed in late November 2003 and the required accelerating voltage of 3.2 MV (800 kV/cavity) was very rapidly achieved soon after. This paper details the SPEAR3 RF system configuration and its new operating requirements, highlighting its installation and subsequent successful operation.

  17. Low jitter RF distribution system

    DOE Patents [OSTI]

    Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

    2012-09-18

    A timing signal distribution system includes an optical frequency stabilized laser signal amplitude modulated at an rf frequency. A transmitter box transmits a first portion of the laser signal and receive a modified optical signal, and outputs a second portion of the laser signal and a portion of the modified optical signal. A first optical fiber carries the first laser signal portion and the modified optical signal, and a second optical fiber carries the second portion of the laser signal and the returned modified optical signal. A receiver box receives the first laser signal portion, shifts the frequency of the first laser signal portion outputs the modified optical signal, and outputs an electrical signal on the basis of the laser signal. A detector at the end of the second optical fiber outputs a signal based on the modified optical signal. An optical delay sensing circuit outputs a data signal based on the detected modified optical signal. An rf phase detect and correct signal circuit outputs a signal corresponding to a phase stabilized rf signal based on the data signal and the frequency received from the receiver box.

  18. First-principles phase diagram calculations for the HfCTiC, ZrCTiC, and HfCZrC solid O. Adjaoud,1,*,

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    -wall coatings for fusion reactors, protective coatings for cutting tools,2 and low-friction coatings

  19. Single electron beam rf feedback free electron laser

    DOE Patents [OSTI]

    Brau, C.A.; Stein, W.E.; Rockwood, S.D.

    1981-02-11

    A free electron laser system and electron beam system for a free electron laser which uses rf feedback to enhance efficiency are described. Rf energy is extracted from a single electron beam by decelerating cavities and energy is returned to accelerating cavities using rf returns, such as rf waveguides, rf feedthroughs, resonant feedthroughs, etc. This rf energy is added to rf klystron energy to reduce the required input energy and thereby enhance energy efficiency of the system.

  20. RF Processing Experience with the GTF Prototype RF Gun

    SciTech Connect (OSTI)

    Schmerge, J.F.

    2010-11-24

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. A total of five different metal cathodes (4 Cu and 1 Mg) have been installed on the GTF gun. The rf processing history with the different cathodes will be presented including peak field achieved at the cathode. The LCLS gun is intended to operate at 120 MV/m and fields up to 140 MV/m have been achieved in the GTF gun. After installing a new cathode the number of rf pulses required to reach 120 MV/m is approximately 5-10 million. Total emitted dark current and Fowler Nordheim plots are also shown over the life of the cathode. The GTF photo-injector gun is an S-band standing-wave structure, with two resonant cavities and an intervening thick washer (Figure 1). The flat, back wall of the first cavity is a copper plate that serves as photocathode when illuminated with ultraviolet light from a pulsed, high-power laser. RF power enters the gun through an iris on the outer wall of the second cavity, and is coupled to the first through the axial opening of the washer. The first cavity is often referred to as a half cell, because its full-cell length has been truncated by the cathode plate and the second cavity is called the full cell. The gun is designed to operate in a {pi} mode, with the peak field on axis in each cell approximately equal. The maximum in the half cell occurs at the cathode, and in the full cell near the center of the cavity. The field profile and tuning procedures are discussed in a separate tech note [1].

  1. RF/optical shared aperture for high availability wideband communication RF/FSO links

    DOE Patents [OSTI]

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2014-04-29

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  2. RF power recovery feedback circulator

    DOE Patents [OSTI]

    Sharamentov, Sergey I. (Bolingbrook, IL)

    2011-03-29

    A device and method for improving the efficiency of RF systems having a Reflective Load. In the preferred embodiment, Reflected Energy from a superconducting resonator of a particle accelerator is reintroduced to the resonator after the phase of the Reflected Energy is aligned with the phase of the Supply Energy from a RF Energy Source. In one embodiment, a Circulator is used to transfer Reflected Energy from the Reflective Load into a Phase Adjuster which aligns the phase of the Reflected Energy with that of the Supply Energy. The phase-aligned energy is then combined with the Supply Energy, and reintroduced into the Reflective Load. In systems having a constant phase shift, the Phase Adjuster may be designed to shift the phase of the Reflected Energy by a constant amount using a Phase Shifter. In systems having a variety (variable) phase shifts, a Phase Shifter controlled by a phase feedback loop comprising a Phase Detector and a Feedback Controller to account for the various phase shifts is preferable.

  3. RF Power Generation in LHC

    E-Print Network [OSTI]

    Brunner, O C; Valuch, D

    2003-01-01

    The counter-rotating proton beams in the Large Hadron Collider (LHC) will be captured and then accelerated to their final energies of 2 x 7 TeV by two identical 400 MHz RF systems. The RF power source required for each beam comprises eight 300 kW klystrons. The output power of each klystron is fed via a circulator and a waveguide line to the input coupler of a single-cell super-conducting (SC) cavity. Four klystrons are powered by a 100 kV, 40A AC/DC power converter, previously used for the operation of the LEP klystrons. A five-gap thyratron crowbar protects the four klystrons in each of these units. The technical specification and measured performance of the various high-power elements are discussed. These include the 400MHz/300kW klystrons with emphasis on their group delay and the three-port circulators, which have to cope with peak reflected power levels up to twice the simultaneously applied incident power of 300 kW. In addition, a novel ferrite loaded waveguide absorber, used as termination for port No...

  4. Microwave (MW) and Radio Frequency (RF) as Enabling Technologies...

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

    Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced...

  5. Thermoelectric Transport in a ZrN/ScN Superlattice

    E-Print Network [OSTI]

    2009-01-01

    at Springerlink.com Thermoelectric Transport in a ZrN/ScNthe potential for a high thermoelectric ?gure of merit. Theexperimental studies of the thermoelectric transport in ZrN/

  6. Multi-level RF identification system

    DOE Patents [OSTI]

    Steele, Kerry D.; Anderson, Gordon A.; Gilbert, Ronald W.

    2004-07-20

    A radio frequency identification system having a radio frequency transceiver for generating a continuous wave RF interrogation signal that impinges upon an RF identification tag. An oscillation circuit in the RF identification tag modulates the interrogation signal with a subcarrier of a predetermined frequency and modulates the frequency-modulated signal back to the transmitting interrogator. The interrogator recovers and analyzes the subcarrier signal and determines its frequency. The interrogator generates an output indicative of the frequency of the subcarrier frequency, thereby identifying the responding RFID tag as one of a "class" of RFID tags configured to respond with a subcarrier signal of a predetermined frequency.

  7. Longitudinal beam dynamics with rf noise

    SciTech Connect (OSTI)

    Shih, H.J.; Ellison, J.A.; Cogburn, R.; Newberger, B.S.

    1993-06-01

    The Dome-Krinsky-Wang (DKW) diffusion-inaction theory for rf-noise-induced emittance dilution is reviewed and related to recent work on the approximation of stochastic processes by Markov processes. An accurate and efficient numerical procedure is developed to integrate the diffusion equation of the DKW theory. Tracking simulations are undertaken to check the validity of the theory in the parameter range of the Superconducting Super Collider (SSC) and to provide additional information. The study of effects of rf noise is applied to two problems of interest at the SSC: (1) determination of noise tolerance levels in the rf system, and (2) feasibility of beam extraction using crystal channeling.

  8. Nb-Pb superconducting RF gun

    SciTech Connect (OSTI)

    J. Sekutowicz; J. Iversen; G. Kreps; W.D. Moller; W. Singer; X. Singer; I. Ben-Zvi; A. Burrill; J. Smedley; T. Rao; M. Ferrario; P. Kneisel; J. Langner; P. Strzyzewski; R. Lefferts; A. Lipski; K. Szalowski; K. Ko; L. Xiao

    2006-04-14

    We report on the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead, as compared to other superconducting metals. The concept, mentioned in a previous paper, follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photon-broken Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.

  9. Matching network for RF plasma source

    DOE Patents [OSTI]

    Pickard, Daniel S. (Palo Alto, CA); Leung, Ka-Ngo (Hercules, CA)

    2007-11-20

    A compact matching network couples an RF power supply to an RF antenna in a plasma generator. The simple and compact impedance matching network matches the plasma load to the impedance of a coaxial transmission line and the output impedance of an RF amplifier at radio frequencies. The matching network is formed of a resonantly tuned circuit formed of a variable capacitor and an inductor in a series resonance configuration, and a ferrite core transformer coupled to the resonantly tuned circuit. This matching network is compact enough to fit in existing compact focused ion beam systems.

  10. Thick Pb(Zr,Ti)O{sub 3} film without substrate

    SciTech Connect (OSTI)

    Lee, Jae-Wung; Park, Chee-Sung; Jo, Ji-Hoon; Kim, Hyoun-Ee [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2007-08-13

    In order to fabricate thick PbZr{sub x}Ti{sub 1-x}O{sub 3} (PZT) films for microelectromechanical system applications, the authors introduce a concept of freestanding film without a substrate. PZT films with a thickness of up to 20 {mu}m were deposited on a very thin Pt layer without a substrate by the rf-magnetron sputtering method using a single oxide target. The Pt layer (thickness <1 {mu}m) was obtained by sputtering the Pt on a Si substrate with a carbon layer between them, and subsequently removing the carbon layer by oxidation in air at 400 deg. C. Piezoelectric properties of the film were comparable to those of bulk PZT as a result of the removal of clamping effect of the substrate.

  11. Fabrication of Niobium sheet for RF cavities 

    E-Print Network [OSTI]

    Balachandran, Shreyas

    2009-05-15

    This thesis investigated the microstructure and mechanical property of RRR( high purity) and RG (low purity) niobium (Nb) sheet material. RRR Nb is used in the fabrication RF cavities. Our method involves processing bulk ...

  12. Conquering Noise for Accurate RF and

    E-Print Network [OSTI]

    Anlage, Steven

    Conquering Noise for Accurate RF and Microwave Signal © Agilent Technologies, Inc. 2009 Microwave Signal Measurements Presented by: Ernie Jackson #12;The Noise Presentation · Review of Basics, Some Advanced & Newer Approaches · Noise in Signal Measurements-Summary · Basic Noise Reduction Approaches

  13. Monolithic RF frontends for ubiquitous wireless connectivity

    E-Print Network [OSTI]

    Goswami, Sushmit

    2014-01-01

    The desire for ubiquitous connectivity is pushing radios towards highly-integrated, multi-standard and multi-band implementations. This thesis explores architectures for next-generation RF frontends, which form the interface ...

  14. Si-based RF MEMS components.

    SciTech Connect (OSTI)

    Stevens, James E.; Nordquist, Christopher Daniel; Baker, Michael Sean; Fleming, James Grant; Stewart, Harold D.; Dyck, Christopher William

    2005-01-01

    Radio frequency microelectromechanical systems (RF MEMS) are an enabling technology for next-generation communications and radar systems in both military and commercial sectors. RF MEMS-based reconfigurable circuits outperform solid-state circuits in terms of insertion loss, linearity, and static power consumption and are advantageous in applications where high signal power and nanosecond switching speeds are not required. We have demonstrated a number of RF MEMS switches on high-resistivity silicon (high-R Si) that were fabricated by leveraging the volume manufacturing processes available in the Microelectronics Development Laboratory (MDL), a Class-1, radiation-hardened CMOS manufacturing facility. We describe novel tungsten and aluminum-based processes, and present results of switches developed in each of these processes. Series and shunt ohmic switches and shunt capacitive switches were successfully demonstrated. The implications of fabricating on high-R Si and suggested future directions for developing low-loss RF MEMS-based circuits are also discussed.

  15. Samsung: ENERGY STAR Referral (RF26VAB)

    Broader source: Energy.gov [DOE]

    DOE referred the matter of Samsung refrigerator-freezer model RF26VAB to the EPA for appropriate action after DOE testing showed that the model does not meet the ENERGY STAR specification.

  16. Deeply scaled CMOS for RF power applications

    E-Print Network [OSTI]

    Scholvin, Jörg, 1976-

    2006-01-01

    The microelectronics industry is striving to reduce the cost, complexity, and form factor of wireless systems through single-chip integration of analog, RF and digital functions. Driven by the requirements of the digital ...

  17. Compression mode resonances in Zr-90 

    E-Print Network [OSTI]

    Youngblood, David H.; Lui, YW; John, B.; Tokimoto, Y.; Clark, HL; Chen, X.

    2004-01-01

    The giant resonance region from 10 MeV < E-x < 55 MeV in Zr-90 has been studied with inelastic scattering of 240 MeV alpha particles at small angles including 0degrees. The isoscalar monopole resonance was found to contain 100 +/- 12% of the E0...

  18. Valence electronenergy-lossspectroscopystudyofZrSiO4 and ZrO2

    SciTech Connect (OSTI)

    Spence, John; Jiang, Nan

    2013-07-01

    ZrSiO4 (zircon) and m-ZrO2 (zirconia) are fundamental and industrially important materials.This work reports the detailed valence electron energy-loss spectroscopy (VEELS) studies of these compounds. The dielectric response functions, as well as single-electron interband transition spectra,are derived from VEELS data for both ZrSiO4 and m-ZrO2, in the rang e5–50 eV using the Kramers–Kronig analysis method. Our interpretation of the interband transitions is given with the aid of ab initio calculations of density of states. The bandgap energies for both materials are also measured using VEELS.The surface and bulk plasmons are identified: the surface plasmon peaks locate at around 12 eV,and two bulk plasmon peaks are ~15–16 eV and ~25–27 eV,respectively.Although similarities in the VEELS exist between ZrSiO4 and m-ZrO2, two majo rdifferences are als onoticed and explained in terms of composition and structure differences.

  19. Micropower RF material proximity sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-01-01

    A level detector or proximity detector for materials capable of sensing through plastic container walls or encapsulating materials is of the sensor. Thus, it can be used in corrosive environments, as well as in a wide variety of applications. An antenna has a characteristic impedance which depends on the materials in proximity to the antenna. An RF oscillator, which includes the antenna and is based on a single transistor in a Colpitt's configuration, produces an oscillating signal. A detector is coupled to the oscillator which signals changes in the oscillating signal caused by changes in the materials in proximity to the antenna. The oscillator is turned on and off at a pulse repetition frequency with a low duty cycle to conserve power. The antenna consists of a straight monopole about one-quarter wavelength long at the nominal frequency of the oscillator. The antenna may be horizontally disposed on a container and very accurately detects the fill level within the container as the material inside the container reaches the level of the antenna.

  20. High-power ELF radiation generated by modulated HF heating of the ionosphere can cause Earthquakes, Cyclones and localized heating

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    transmitter radiates a strong beam of high- frequency (HF) waves modulated at ELF. This HF heating modulates-frequency (HF) radiation in the megahertz range [7]. This heating modulates the electron's temperature in the D

  1. HF Radio in the International Information Infrastructure Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    HF Radio in the International Information Infrastructure Eric E. Johnson New Mexico State into the rapidly expanding global Internet. 1. INTRODUCTION Advancements in the international information network and the Internet (the latter relying largely upon the services of the former). However, some

  2. Interactions Among Ionospheric Propagation, HF Modems, and Data Protocols

    E-Print Network [OSTI]

    Johnson, Eric E.

    Mexico State University Abstract The well-known challenges in using the ionospheric skywave channel to Internet-style network- and ap- plication-layer protocols, which have been designed with reliable, high that will form the basis of reliable Internet operation via next-generation HF radio networks. Introduction

  3. ARQ PROTOCOL FEATURES FOR HF RADIO LINKS Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    ARQ PROTOCOL FEATURES FOR HF RADIO LINKS Eric E. Johnson New Mexico State University ABSTRACT The explosion of interest in using Internet-style applica- tions over wireless links prompts investigation links with Internet-style workloads. The investigation is focused on high-frequency radio links

  4. ELF/VLF PHASED ARRAY GENERATION VIA FREQUENCY-MATCHED STEERING OF A CONTINUOUS HF

    E-Print Network [OSTI]

    -OFF modulation of this HF energy can impose an ELF/VLF alternating current onto those natural currents. This technique turns the lower atmosphere into a large antenna, which radiates energy downward into the Earth.6 MW HAARP HF heating facility in Alaska, we show that proper utilization of motion of the HF beam can

  5. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    SciTech Connect (OSTI)

    Johnson, Rolland

    2014-09-21

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A 1.3 GHz RF test cell capable of operating both at high pressure and in vacuum with replaceable electrodes was designed, built, and power tested in preparation for testing the frequency and geometry effects of RF breakdown at Argonne National Lab. At the time of this report this cavity is still waiting for the 1.3 GHz klystron to be available at the Wakefield Test Facility. (3) Under a contract with Los Alamos National Lab, an 805 MHz RF test cavity, known as the All-Seasons Cavity (ASC), was designed and built by Muons, Inc. to operate either at high pressure or under vacuum. The LANL project to use the (ASC) was cancelled and the testing of the cavity has been continued under the grant reported on here using the Fermilab Mucool Test Area (MTA). The ASC is a true pillbox cavity that has performed under vacuum in high external magnetic field better than any other and has demonstrated that the high required accelerating gradients for many muon cooling beam line designs are possible. (4) Under ongoing support from the Muon Acceleration Program, microscopic surface analysis and computer simulations have been used to develop models of RF breakdown that apply to both pressurized and vacuum cavities. The understanding of RF breakdown will lead to better designs of RF cavities for many applications. An increase in the operating accelerating gradient, improved reliability and shorter conditioning times can generate very significant cost savings in many accelerator projects.

  6. Characteristics of Interconnected Delta-Hydride Precipitates in Zr

    SciTech Connect (OSTI)

    L.J. Carroll; M.R. Tonks; T.M. Lillo; B.S. Fromm; DC Haggard; T.C. Morris; W.D. Swank; T.L. Trowbridge; M.C. Carroll

    2014-09-01

    Characterization of extended delta-ZrH1.66 structures in unalloyed zirconium by electron backscatter diffraction analysis confirms that they consist of many interconnected precipitates of multiple, but distinctly related, orientations. The expected orientation relationship of (0001)a-Zr//(111)delta-ZrH1.66 is confirmed between the hydride and one of the surrounding a-Zr matrix grains. The delta-ZrH1.66 precipitates do not extend in a discrete crystalline orientation, but are regularly divided by 60° type {111} twins in which adjacent delta-ZrH1.66 grains share a {111} plane. The observed matching of the close-packed FCC planes of impinging or twinned hydrides within an interconnected structure enables the minimization of the overall interfacial energy through successive nucleation and growth events and twinning.

  7. RF-Photonic Frequency Stability Gear Box

    E-Print Network [OSTI]

    Matsko, Andrey B; Ilchenko, Vladimir S; Seidel, David; Maleki, Lute

    2011-01-01

    An optical technique based on stability transfer among modes of a monolithic optical microresonator is proposed for long therm frequency stabilization of a radiofrequency (RF) oscillator. We show that locking two resonator modes, characterized with dissimilar sensitivity in responding to an applied forcing function, to a master RF oscillator allows enhancing the long term stability of a slave RF oscillator locked to two resonator modes having nearly identical sensitivity. For instance, the stability of a 10 MHz master oscillator characterized with Allan deviation of 10^-7 at 10^4s can be increased and transferred to a slave oscillator with identical stability performance, so that the resultant Allan deviation of the slave oscillator becomes equal to 10-13 at 10^4s. The method does not require absolute frequency references to achieve such a performance.

  8. X-Band RF Gun Development

    SciTech Connect (OSTI)

    Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami; Anderson, Scott; Hartemann, Fred; Marsh, Roark; /LLNL, Livermore

    2012-06-22

    In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into the structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.

  9. High RF Power Production for CLIC

    E-Print Network [OSTI]

    Syratchev, I; Adli, E; Taborelli, M

    2007-01-01

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous mode. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and delivered to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability and main linac RF power needs. Another requirement is to provide local RF power termination in case of accelerating structure failure (ON/OFF capability). Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design

  10. Design and fabrication of an RF power LDMOSFET on SOI

    E-Print Network [OSTI]

    Fiorenza, James G. (James George), 1972-

    2002-01-01

    This thesis studied thin-film Silicon-on-Insulator (SOI) LDMOSFET technology for RF power amplifier applications. To conduct this study, two generations of SOI RF power devices for portable wireless systems were designed ...

  11. eZ430-RF2500 Development Tool User's Guide

    E-Print Network [OSTI]

    ............................................................................................................... 6 2 eZ430-RF2500 Battery Board....................................................... 10 5 9600 bps With No Flow Control

  12. RF Design of the LCLS Gun

    SciTech Connect (OSTI)

    Limborg-Deprey, C

    2010-12-13

    Final dimensions for the LCLS RF gun are described. This gun, referred to as the LCLS gun, is a modified version of the UCLA/BNL/SLAC 1.6 cell S-Band RF gun [1], referred to as the prototype gun. The changes include a larger mode separation (15 MHz for the LCLS gun vs. 3.5 MHz for the prototype gun), a larger radius at the iris between the 2 cells, a reduced surface field on the curvature of the iris between the two cells, Z power coupling, increased cooling channels for operation at 120 Hz, dual rf feed, deformation tuning of the full cell, and field probes in both cells. Temporal shaping of the klystron pulse, to reduce the average power dissipated in the gun, has also been adopted. By increasing the mode separation, the amplitude of the 0-mode electric field on the cathode decreases from 10% of the peak on axis field for the prototype gun to less than 3% for the LCLS gun for the steady state fields. Beam performance is improved as shown by the PARMELA simulations. The gun should be designed to accept a future load lock system. Modifications follow the recommendations of our RF review committee [2]. Files and reference documents are compiled in Section IV.

  13. Graphene-Study, Kaprun, March 27th 2015, noise / ballistics in graphene, B. Plaais 1/80 WP4 -HF Electronics HF-Graphene Electronics

    E-Print Network [OSTI]

    Plaçais, Bernard

    Graphene-Study, Kaprun, March 27th 2015, noise / ballistics in graphene, B. Plaçais 1/80 WP4 - HF Electronics HF-Graphene Electronics noise (L1) ballistic's (L2) (electron-phonon) (Dirac Fermion Optics) Bernard Plaçais placais@lpa.ens.fr #12;Graphene-Study, Kaprun, March 27th 2015, noise / ballistics

  14. RF MEMS DC CONTACT SWTCHES FOR RECONFIGURABLE Presented to the

    E-Print Network [OSTI]

    Kassegne, Samuel Kinde

    RF MEMS DC CONTACT SWTCHES FOR RECONFIGURABLE ANTENNAS _______________ A Thesis Presented STATE UNIVERSITY The Undersigned Faculty Committee Approves the Thesis of Lei Zhou: RF DC Contact MEMS rock and water, water, through persistence, eventually wins. #12;vi ABSTRACT OF THE THESIS RF MEMS DC

  15. Analysis of Third-Generation HF ALE Technologies Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    Analysis of Third-Generation HF ALE Technologies Eric E. Johnson New Mexico State University · Higher throughput for short and long data messages · Better support for Internet protocols

  16. Rugged Ceramic Window for RF Applications

    SciTech Connect (OSTI)

    Neubauer, Michael; Johnson, Rolland P.; Rimmer, Robert; Elliot, Tom; Stirbet, Mircea

    2009-05-04

    High-current RF cavities that are needed for many accelerator applications are often limited by the power transmission capability of the pressure barriers (windows) that separate the cavity from the power source. Most efforts to improve RF window design have focused on alumina ceramic, the most popular historical choice, and have not taken advantage of new materials. Alternative window materials have been investigated using a novel Merit Factor comparison and likely candidates have been tested for the material properties which will enable construction in the self-matched window configuration. Window assemblies have also been modeled and fabricated using compressed window techniques which have proven to increase the power handling capability of waveguide windows. Candidate materials have been chosen to be used in fabricating a window for high power testing at Thomas Jefferson National Accelerator Facility.

  17. An Efficient RF Source for Jlab

    SciTech Connect (OSTI)

    Neubauer, M.; Dudas, A.; Rimmer, Robert A.; Wang, Haipeng

    2013-12-01

    We propose the development of a highly reliable high efficiency RF source for JLAB with a lower lifetime cost operating at 80% efficiency with system operating costs of about 0.7M$/year for the 6 GeV machine. The design of the RF source will be based upon two injection locked magnetrons in a novel combining architecture for amplitude modulation and a cross field amplifier (CFA) as an output tube for the 12 GeV upgrade. A cost analysis including efficiency and reliability will be performed to determine the optimum system architecture. Several different system architectures will be designed and evaluated for a dual injection locked magnetron source using novel combining techniques and possibly a CFA as the output tube. A paper design for the 1497 MHz magnetron system will be completed. The optimum system architecture with all relevant specifications will be completed so that a prototype can be built.

  18. ILC RF System R and D

    SciTech Connect (OSTI)

    Adolphsen, Chris; /SLAC

    2012-07-03

    The Linac Group at SLAC is actively pursuing a broad range of R&D to improve the reliability and reduce the cost of the L-band (1.3 GHz) rf system proposed for the ILC linacs. Current activities include the long-term evaluation of a 120 kV Marx Modulator driving a 10 MW Multi-Beam Klystron, design of a second-generation Marx Modulator, testing of a sheet-beam gun and beam transport system for a klystron, construction of an rf distribution system with remotely-adjustable power tapoffs, and development of a system to combine the power from many klystrons in low-loss circular waveguide where it would be tapped-off periodically to power groups of cavities. This paper surveys progress during the past few years.

  19. The new RF sources for accelerators

    SciTech Connect (OSTI)

    Ives, Lawrence; Read, Michael; Ferguson, Patrick; Marsden, David; Collins, George; Jackson, R. H.; Bui, Thuc; Kimura, Takuji; Eisen, Edward [Calabazas Creek Research, Inc., 690 Port Drive, San Mateo, CA, 94404, (650) 312-9575 (United States); Communications and Power Industries, LLC., 811 Hansen Way, Palo Alto, CA94304 (United States)

    2012-12-21

    Several new RF sources are being developed for accelerator and collider applications. Assembly is nearing completion of a multiple beam inductive output tube at 352 MHz. An annular beam klystron is being developed to produce 10 MW pulses at 1.3 GHz. The annular beam approach provides significant cost reduction over similar multiple beam devices. Fabrication is underway on a 10 kW, periodic permanent magnet klystron at 2.815 GHz. Permanent magnets eliminate the solenoid and associated power supplies and cooling requirements to reduce operational cost. Investigations are beginning on a novel approach for driving accelerator cavities using pulse shaping to increase coupling efficiency and dramatically reduce RF power requirements.

  20. RUGGED CERAMIC WINDOW FOR RF APPLICATIONS

    SciTech Connect (OSTI)

    MIKE NEUBAUER

    2012-11-01

    High-current RF cavities that are needed for many accelerator applications are often limited by the power transmission capability of the pressure barriers (windows) that separate the cavity from the power source. Most efforts to improve RF window design have focused on alumina ceramic, the most popular historical choice, and have not taken advantage of new materials. Alternative window materials have been investigated using a novel Merit Factor comparison and likely candidates have been tested for the material properties which will enable construction in the self-matched window configuration. Window assemblies have also been modeled and fabricated using compressed window techniques which have proven to increase the power handling capability of waveguide windows. Candidate materials have been chosen to be used in fabricating a window for high power testing at Thomas Jefferson National Accelerator Facility.

  1. Survey reveals nature of corrosion in HF alky units

    SciTech Connect (OSTI)

    Dobis, J.D. (BP Oil Co., Marcus Hook, PA (United States)); Clarida, D.R. (Conoco Inc., Ponca City, OK (United States)); Richert, J.P. (Saudi Aramco/Mobil, Yanbu (Saudi Arabia))

    1995-03-06

    The results of a National Association of Corrosion Engineers survey of 62 HF alkylation units reveal relatively low incidence of service-related cracking of carbon steel. Hydrogen blistering, however, is prevalent, especially in the main acid circuit and overhead condensers. Based on these and other survey results, several recommendations are made to enable refiners to monitor and reduce corrosion in these special units. The paper discusses the survey results, construction materials, post-weld heat treatments, small-diameter piping, construction inspection, bolting, gaskets, block valves, maintenance practices, cracking, blistering, areas of vulnerability, and recommendations.

  2. Cathode Ion Bombardment in RF Photoguns

    SciTech Connect (OSTI)

    Pozdeyev,E.; Kayran, D.; Litvinenko, V.

    2008-09-01

    In this paper, we use the method of rapid oscillating field to solve the equation of ion motion in an RF gun. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper proposes a simple mitigation recipe that can reduce the rate of ion bombardment.

  3. RF Gun Photocathode Research at SLAC

    SciTech Connect (OSTI)

    Jongewaard, E.; Akre, R.; Brachmann, A.; Corbett, J.; Gilevich, S.; Grouev, K.; Hering, P.; P.Krejcik,; Lewandowski, J.; Loos, H.; Montagne, T.; Sheppard, J.C.; Stefan, P.; Vlieks, A.; Weathersby, S.; Zhou, F.; /SLAC

    2012-05-16

    LCLS is presently operating with a third copper photocathode in the original rf gun, with a quantum efficiency (QE) of {approx}1 x 10{sup -4} and projected emittance {gamma}{var_epsilon}{sub x,y} = 0.45 {micro}m at 250 pC bunch charge. The spare LCLS gun is installed in the SLAC Accelerator Structure Test Area (ASTA), fully processed to high rf power. As part of a wider photocathode R and D program, a UV laser system and additional gun diagnostics are being installed at ASTA to measure QE, QE lifetime, and electron beam emittance under a variety of operating conditions. The near-term goals are to test and verify the spare photocathode production/installation sequence, including transfer from the final holding chamber to the rf gun. Mid- and longer-term goals include development of a rigorous understanding of plasma and laser-assisted surface conditioning and investigation of new, high-QE photocathode materials. In parallel, an x-ray photoemission spectroscopy station is nearing completion, to analyze Cu photocathode surface chemistry. In this paper we review the status and anticipated operating parameters of ASTA and the spectroscopy test chamber.

  4. The Murmansk Initiative - RF: Acceptance Testing

    SciTech Connect (OSTI)

    Czajkowski, C.; Wester, D. W.; Dyer, R. S.; Soerlie, A. A.; Moller, B.; Barnes, E.

    2002-02-26

    The Murmansk Initiative-RF (MI) was conceived to provide the Russian Federation (RF) with the capacity to manage low-level liquid radioactive waste (LLRW) and comply with the requirements of the London Convention that prohibit ocean dumping. The trilateral project among Norway, the RF, and the United States of America (U.S.) began in 1994 and was the first to utilize exclusively Russian subcontractors to upgrade and expand an existing LLRW treatment plant on the premises of RTP Atomflot in Murmansk, Russia. The project moved quickly through the design phase. Progress during the construction phase was somewhat slower because of difficulties with acquisition of hardware, inexperience with automated instrumentation and control equipment, and unexpected design changes in the cementation unit. The project advanced into the test-operation phase, which is currently underway, in June 2001. Initial runs with liquid waste have revealed that procedures for unloading spent ion-exchange sorbents could be improved and that sludges formed during removal of alkaline-earth metals should be compacted in order for the facility to operate at its full potential. Resolution of these issues is expected within the next few months.

  5. Reducing the Heat Load on the LCLS 120 Hz RF Gun with RF Pulse Shaping

    SciTech Connect (OSTI)

    Schmerge, J.

    2005-01-31

    The LCLS injector must operate at 120 Hz repetition frequency but to date the maximum operating frequency of an S-band rf gun has been 50 Hz. The high fields desired for the LCLS gun operation limit the repetition frequency due to thermal expansion causing rf detuning and field redistribution. One method of addressing the thermal loading problem is too reduce the power lost on the cavity walls by properly shaping the rf pulse incident on the gun. The idea is to reach the steady state field value in the gun faster than the time constant of the gun would allow when using a flat incident rf pulse. By increasing the incident power by about a factor of three and then decreasing the incident power when the field reaches the desired value in the gun, the field build up time can be decreased by more than a factor of three. Using this technique the heat load is also decreased by more than a factor of three. In addition the rf coupling coefficient can be increased from the typical critically coupled designs to an overcoupled design which also helps reduce the field build up time. Increasing the coupling coefficient from 1 to 2 reduces the heat load by another 25% and still limits the reflected power and coupling hole size to manageable levels.

  6. Strong H...F hydrogen bonds as synthons in polymeric quantum magnets: structural, magnetic, and theoretical characterization of [Cu(HF)(pyrazine)]SbF, [CuF(HF)(FH)(pyrazine)].(SbF), and [CuAg(HF)(pyrazine)](SbF).

    SciTech Connect (OSTI)

    Manson, J. L.; Schlueter, J. A.; Funk, K. A.; Southerland, H. I.; Twamley, B.; Lancaster, T.; Blundell, S. J.; Baker, P. J.; Pratt, F. L.; Singleton, J.; McDonald, R. D.; Goddard, P. A.; Sengupta, P.; Batista, C. D.; Ding, L.; Lee, C.; Whangbo, M.-H.; Franke, I.; Cox, S.; Baines, C.; Trail, D.; Eastern Washington Univ.; Univ. of Idaho; Oxford Univ.; Rutherford Appleton Lab.; LANL; Univ. of Southern California; North Carolina State Univ.; Paul Scherrer Inst.

    2009-01-01

    Three Cu{sup 2+}-containing coordination polymers were synthesized and characterized by experimental (X-ray diffraction, magnetic susceptibility, pulsed-field magnetization, heat capacity, and muon-spin relaxation) and electronic structure studies (quantum Monte Carlo simulations and density functional theory calculations). [Cu(HF{sub 2})(pyz){sub 2}]SbF{sub 6} (pyz = pyrazine) (1a), [Cu{sub 2}F(HF)(HF{sub 2})(pyz){sub 4}](SbF{sub 6}){sub 2} (1b), and [CuAg(H{sub 3}F{sub 4})(pyz){sub 5}](SbF{sub 6}){sub 2} (2) crystallize in either tetragonal or orthorhombic space groups; their structures consist of 2D square layers of [M(pyz){sub 2}]{sup n+} that are linked in the third dimension by either HF{sub 2}{sup -} (1a and 1b) or H{sub 3}F{sub 4}{sup -} (2). The resulting 3D frameworks contain charge-balancing SbF{sub 6}{sup -} anions in every void. Compound 1b is a defective polymorph of 1a, with the difference being that 50% of the HF{sub 2}{sup -} links are broken in the former, which leads to a cooperative Jahn-Teller distortion and d{sub x{sup 2}-y{sup 2}} orbital ordering. Magnetic data for 1a and 1b reveal broad maxima in x at 12.5 and 2.6 K and long-range magnetic order below 4.3 and 1.7 K, respectively, while 2 displays negligible spin interactions owing to long and disrupted superexchange pathways. The isothermal magnetization, M(B), for 1a and 1b measured at 0.5 K reveals contrasting behaviors: 1a exhibits a concave shape as B increases to a saturation field, B{sub c}, of 37.6 T, whereas 1b presents an unusual two-step saturation in which M(B) is convex until it reaches a step near 10.8 T and then becomes concave until saturation is reached at 15.8 T. The step occurs at two-thirds of M{sub sat}, suggesting the presence of a ferrimagnetic structure. Compound 2 shows unusual hysteresis in M(B) at low temperature, although x vs T does not reveal the presence of a magnetic phase transition. Quantum Monte Carlo simulations based on an anisotropic cubic lattice were applied to the magnetic data of 1a to afford g = 2.14, J = ?13.4 K (Cu-pyz-Cu), and J = ?0.20 K (Cu?F {hor_ellipsis} H {hor_ellipsis} F?Cu), while x vs T for 1b could be well reproduced by a spin-1/2 Heisenberg uniform chain model for g = 2.127(1), J{sub 1} = ?3.81(1), and zJ{sub 2} = ?0.48(1) K, where J{sub 1} and J{sub 2} are the intra- and interchain exchange couplings, respectively, which considers the number of magnetic nearest-neighbors (z). The M(B) data for 1b could not be satisfactorily explained by the chain model, suggesting a more complex magnetic structure in the ordered state and the need for additional terms in the spin Hamiltonian. The observed variation in magnetic behaviors is driven by differences in the H {hor_ellipsis} F hydrogen-bonding motifs.

  7. Design and Manufacture of the RF Power Supply and RF Transmission Line for SANAEM Project Prometheus

    E-Print Network [OSTI]

    Turemen, G; Unel, G; Alacakir, A

    2015-01-01

    A 1-5 MeV proton beamline is being built by the Turkish Atomic Energy Authority in collaboration with a number of graduate students from different universities. The most important aspect of the project, is to acquire the design ability and manufacturing capability of all the components locally. SPP will be an accelerator and beam diagnostics test facility and it will also serve the detector development community with its low beam current. This paper discusses the design and construction of the RF power supply and the RF transmission line components such as its waveguide converters and its circulator.

  8. Realization and modeling of rf superconducting quantum interference device metamaterials

    E-Print Network [OSTI]

    M. Trepanier; Daimeng Zhang; Oleg Mukhanov; Steven M. Anlage

    2013-10-28

    We have prepared meta-atoms based on radio frequency superconducting quantum interference devices (RF SQUIDs) and examined their tunability with dc magnetic field, rf current, and temperature. RF SQUIDs are superconducting split ring resonators in which the usual capacitance is supplemented with a Josephson junction, which introduces strong nonlinearity in the rf properties. We find excellent agreement between the data and a model which regards the Josephson junction as the resistively and capacitively-shunted junction. A magnetic field tunability of 80 THz/Gauss at 12 GHz is observed, a total tunability of 56$%$ is achieved, and a unique electromagnetically-induced transparency feature at intermediate excitation powers is demonstrated for the first time. An RF SQUID metamaterial is shown to have qualitatively the same behavior as a single RF SQUID with regards to DC flux and temperature tuning.

  9. EM modeling of RF drive in DTL tank 4

    SciTech Connect (OSTI)

    Kurennoy, Sergey S.

    2012-06-19

    A 3-D MicroWave Studio model for the RF drive in the LANSCE DTL tank 4 has been built. Both eigensolver and time-domain modeling are used to evaluate maximal fields in the drive module and RF coupling. The LANSCE DTL tank 4 has recently been experiencing RF problems, which may or may not be related to its replaced RF coupler. This situation stimulated a request by Dan Rees to provide EM modeling of the RF drive in the DTL tank 4 (T4). Jim O'Hara provided a CAD model that was imported into the CST Microwave Studio (MWS) and after some modifications became a part of a simplified MWS model of the T4 RF drive. This technical note describes the model and presents simulation results.

  10. Phosphonic-Based HF Acid: Interactions With Clay Minerals And Flow In Sandstone Cores 

    E-Print Network [OSTI]

    Zhou, Lijun

    2015-05-13

    , phosphonic-based HF acid systems (HF and a phosphonic acid) have been used as an alternative to mud acid. However, very limited research has been performed to investigate the interactions of phosphonic-based acid systems with clay minerals in sandstone...

  11. Finland HF and Esrange MST radar observations of polar mesosphere summer echoes

    E-Print Network [OSTI]

    Kirkwood, Sheila

    Finland HF and Esrange MST radar observations of polar mesosphere summer echoes Tadahiko Ogawa1 (200x) xx:1­8 Finland HF and Esrange MST radar observations of polar mesosphere summer echoes Tadahiko in Finland are presented. The echoes were detected at four frequencies of 9, 11, 13 and 15 MHz at slant

  12. Measurement and analysis of muonic x rays of 176,177,178,179,180Hf

    SciTech Connect (OSTI)

    Tanaka, Y.; Steffen, R.M.; Shera, E.B.; Reuter, W.; Hoehn, M.V.; Zumbro, J.D.

    1984-07-01

    Monopole and quadrupole charge distributions of /sup 176/Hf, /sup 177/Hf, /sup 178/Hf, /sup 179/Hf, and /sup 180/Hf were investigated by muonic atom K and L x-ray measurements. The model-independent Barrett charge radii R/sub k/ and the isotope shifts ..delta..R/sub k/ were measured, and values of and ..delta.. were deduced. A weak odd-even staggering of the nuclear charge radii was observed for the series /sup 176 -178/Hf and /sup 178 -180/Hf. A large negative isomer shift was observed in the 2/sup +/ state of the /sup 176/Hf nucleus, a fact that existing theories do not explain. The quadrupole moments of the first excited states of the hafnium nuclei were determined to be Q/sup 176/(2/sup +/) = -2.10(2) e b, Q/sup 177/((9/2)/sup -/) = 1.30(2) e b, Q/sup 178/(2/sup +/) = -2.02(2) e b, Q/sup 179/((11/2)/sup +/) = 1.88(3) e b, and Q/sup 180/(2/sup +/) = -2.00(2) e b. These quadrupole moments and the simultaneously determined B(E2) values for the respective nuclei are in satisfactory agreement with the predictions of the axially symmetric rotor model.

  13. Effects of heat treatment and HF etching on the strength of silica lightguides

    E-Print Network [OSTI]

    Matthewson, M. John

    Effects of heat treatment and HF etching on the strength of silica lightguides C. R. Kurkjian, M. J, heating of a fiber to moderate temperatures (~300 600 C), for instance during the soldering of pigtails-lowering defects. In this paper we discuss early results from the literature on the effects of heating and HF

  14. DFT STUDY REVISES INTERSTITIAL CONFIGURATIONS IN HCP Zr

    SciTech Connect (OSTI)

    Samolyuk, German D; Golubov, Stanislav I; Osetskiy, Yury N; Stoller, Roger E

    2012-06-01

    Analysis of experimental result on microstructure evolution in irradiated Zr and alloys has demonstrated that available knowledge on self-interstitial defects in Zr is in contradiction. We therefore have initiated an extensive theoretical and modeling program to clarify this issue. In this report we present first ab initio calculations results of single SIA configurations in Zr. We demonstrate importance of simulations cell size, applied exchange-correlation functional and simulated c/a ratio. The results obtained demonstrate clearly that the most stable configurations are in basal plane and provide some evidences for enhanced interstitial transport along basal planes. The results obtained will be used in generation a new interatomic potential for Zr to be used in large-scale atomistic modeling of mechanisms relevant for radiation-induced microstructure evolution.

  15. Crystal structure of Si-doped HfO{sub 2}

    SciTech Connect (OSTI)

    Zhao, Lili [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); School of Information Science and Technology, Northwest University, Xi'an 710127 (China); Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Nelson, Matthew; Fancher, Chris M. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Aldridge, Henry [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Iamsasri, Thanakorn; Forrester, Jennifer S.; Jones, Jacob L., E-mail: jacobjones@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Nishida, Toshikazu [Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida 32611 (United States); Moghaddam, Saeed [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States)

    2014-01-21

    Si-doped HfO{sub 2} was prepared by solid state synthesis of the starting oxides. Using Rietveld refinement of high resolution X-ray diffraction patterns, a substitutional limit of Si in HfO{sub 2} was determined as less than 9 at.?%. A second phase was identified as Cristobalite (SiO{sub 2}) rather than HfSiO{sub 4}, the latter of which would be expected from existing SiO{sub 2}-HfO{sub 2} phase diagrams. Crystallographic refinement with increased Si-dopant concentration in monoclinic HfO{sub 2} shows that c/b increases, while ? decreases. The spontaneous strain, which characterizes the ferroelastic distortion of the unit cell, was calculated and shown to decrease with increasing Si substitution.

  16. Investigation of Microscopic Materials Limitations of Superconducting RF Cavities

    SciTech Connect (OSTI)

    Anlage, Steven

    2014-07-23

    The high-field performance of SRF cavities is often limited by breakdown events below the intrinsic limiting surface fields of Nb, and there is abundant evidence that these breakdown events are localized in space inside the cavity. Also, there is a lack of detailed understanding of the causal links between surface treatments and ultimate RF performance at low temperatures. An understanding of these links would provide a clear roadmap for improvement of SRF cavity performance, and establish a cause-and-effect ‘RF materials science’ of Nb. We propose two specific microscopic approaches to addressing these issues. First is a spatially-resolved local microwave-microscope probe that operates at SRF frequencies and temperatures to discover the microscopic origins of breakdown, and produce quantitative measurements of RF critical fields of coatings and films. Second, RF Laser Scanning Microscopy (LSM) has allowed visualization of RF current flow and sources of nonlinear RF response in superconducting devices with micro-meter spatial resolution. The LSM will be used in conjunction with surface preparation and characterization techniques to create definitive links between physical and chemical processing steps and ultimate cryogenic microwave performance. We propose to develop RF laser scanning microscopy of small-sample Nb pieces to establish surface-processing / RF performance relations through measurement of RF current distributions on micron-length scales and low temperatures.

  17. Multi-Physics Analysis of the Fermilab Booster RF Cavity

    SciTech Connect (OSTI)

    Awida, M.; Reid, J.; Yakovlev, V.; Lebedev, V.; Khabiboulline, T.; Champion, M.; /Fermilab

    2012-05-14

    After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.

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

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

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

  19. DEVELOPMENT AND TESTING OF HIGH POWER RF VECTOR MODULATORS*

    SciTech Connect (OSTI)

    Kang, Yoon W [ORNL; Wilson, Joshua L [ORNL; Champion, Mark [FNAL; Hardek, Thomas W [ORNL; Kim, Sang-Ho [ORNL; McCarthy, Mike [ORNL; Vassioutchenko, Alexandre V [ORNL

    2007-01-01

    A fan-out RF power distribution system can allow many accelerating cavities to be powered by a single high-power klystron amplifier. High-power vector modulators can perform independent control of amplitudes and phases of RF voltages at the cavities without changing the klystron signal. A prototype highpower RF vector modulator employing a quadrature hybrid and two ferrite phase shifters in coaxial TEM transmission lines has been built and tested for 402.5 MHz. RF properties of the design and results of high power testing are presented.

  20. Locking Lasers to RF in an Ultra Fast FEL

    E-Print Network [OSTI]

    Wilcox, R.

    2011-01-01

    Lasers to RF in an Ultrafast FEL R. B . Wilcox, G . Huang,the X-ray pulses from the FEL. The phase-locked loop on the

  1. Active high-power RF switch and pulse compression system

    DOE Patents [OSTI]

    Tantawi, Sami G. (San Mateo, CA); Ruth, Ronald D. (Woodside, CA); Zolotorev, Max (Mountain View, CA)

    1998-01-01

    A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power. The switch is useful to the construction of an improved pulse compression system to boost the peak power of microwave tubes driving linear accelerators. In this application, the high-power RF switch is placed at the coupling iris between the charging waveguide and the resonant storage line of a pulse compression system. This optically controlled high power RF pulse compression system can handle hundreds of Megawatts of power at X-band.

  2. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 16, NO. 5, OCTOBER 2007 1185 RF MEMS Sequentially Reconfigurable Sierpinski

    E-Print Network [OSTI]

    Tentzeris, Manos

    JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 16, NO. 5, OCTOBER 2007 1185 RF MEMS Sequentially, RF microelectromechanical systems (RF MEMS), Sierpinski fractal antenna. I. INTRODUCTION THE RF microelectromechanical systems (RF MEMS) switches are quickly becoming a popular switching ele- ment among microwave

  3. Safety Slide 1 Hydrofluoric (HF) Acid Hazards http://www.emsworld.com/web/online/Education/Hydrofluoric-Acid-/5$12949

    E-Print Network [OSTI]

    Cohen, Robert E.

    Safety Slide 1 ­ Hydrofluoric (HF) Acid Hazards http://www.emsworld.com/web may be delayed for up to 24 hours, even with dilute solutions. HF burns affect deep tissue layers

  4. CLIC RF High Power Production Testing Program

    E-Print Network [OSTI]

    Syratchev, I; Tantawi, S

    2008-01-01

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and generate RF power for the main linac accelerating structure. The demands on the high power production (~ 150 MW) and the needs to transport the 100 A drive beam for about 1 km without losses, makes the PETS design rather unique and the operation very challenging. In the coming year, an intense PETS testing program will be implemented. The target is to demonstrate the full performance of the PETS operation. The testing program overview and test results available to date are presented.

  5. Sandia National Laboratories: RF & Photonics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-ThroughputUpcoming Release of thePrograms:Mode Stirred ChamberReuseQuantum SystemsRF

  6. Synthesis of Na-Stabilized Nonporous tZrO2 Supports and Pt/t-ZrO2 Catalysts and Application to Water-Gas-Shift Reaction

    E-Print Network [OSTI]

    Poeppelmeier, Kenneth R.

    steam reforming,10 and epoxidation of olefins.11 ZrO2 exists primarily in three different polymorphs significantly affect the catalytic performance for chemical reactions. Ma et al. prepared t-ZrO2 using Na2CO3 catalytic performance for methanol synthesis from CO hydrogenation compared to amorphous and m-ZrO2

  7. Extremely high frequency RF effects on electronics.

    SciTech Connect (OSTI)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  8. Recent advances in RF power generation

    SciTech Connect (OSTI)

    Tallerico, P.J.

    1990-01-01

    This paper is a review of the progress and methods used in RF generation for particle accelerators. The frequencies of interest are from a few megahertz to 100 GHz, and the powers are for super linear collider applications, but in this case the pulses are short, generally below 1 {mu}s. The very high-power, short-pulse generators are only lightly reviewed here, and for more details the reader should follow the specialized references. Different RF generators excel over various parts of the frequency spectrum. Below 100 MHz solid-state devices and gridded tubes prevail, while the region between 400 MHz and 3 GHz, the cyclotron-resonant devices predominate, and above 250 GHz, Free-Electron Lasers and ubitrons are the most powerful generators. The emphasis for this review is on microwave generation at frequencies below 20 GHz, so the cyclotron-resonant devices are only partially reviewed, while the progress on free-electron laser and ubitrons is not reviewed in this paper. 39 refs., 4 figs.

  9. High performance RF MEMS metal-contact switches and switching networks

    E-Print Network [OSTI]

    Patel, Chirag D.; Patel, Chirag D.

    2012-01-01

    A Compact Cantilever-Based RF MEMS Switch andA High-Performance RF MEMS Metal-Contact Switch and Switch-B High-Q 3-/4-Bit RF MEMS Digitally Tunable Capacitors for

  10. Quasi-optical network analyzers and high-reliability RF MEMS switched capacitors

    E-Print Network [OSTI]

    Grichener, Alexander

    2011-01-01

    Chapter 3 High-Reliability RF MEMS Switched Capacitors 3.1Technology 1.2 RF MEMS Technology . . . . . . . . . . . . .Reliability High-Q Switched RF MEMS Capacitors” IEEE Int.

  11. Cooling at the quantum limit and RF refrigeration

    E-Print Network [OSTI]

    Fominov, Yakov

    Cooling at the quantum limit and RF refrigeration Jukka Pekola Low Temperature Laboratory, Helsinki (electromagnetic) heat transport Cooling at the quantum limit: experiments RF refrigeration in a single as a refrigerator Optimum cooling power is reached at V 2/e: Cooling power of a NIS junction: Temperature TN

  12. RF Power Potential of 45 nm CMOS Technology Usha Gogineni

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    RF Power Potential of 45 nm CMOS Technology Usha Gogineni 1 , Jesús A. del Alamo 1 devices in recent years has motivated their use in millimeter-wave power applications. Specific, VT Abstract - This paper presents the first measurements of the RF power performance of 45 nm CMOS

  13. DEVELOPMENT OF BROADBAND LOW-VOLTAGE RF MEM SWITCHES

    E-Print Network [OSTI]

    Shen, Shyh-Chiang

    DEVELOPMENT OF BROADBAND LOW-VOLTAGE RF MEM SWITCHES S.C. Shen, D. T. Becher, D. C. Caruth, and M)333-4054 Fax: (217) 244-6375 Abstract We present novel RF switches using micro-electro- mechanical (MEM) technology. These MEM switches are built on GaAs substrates using GaAs MESFET MMIC- compatible processes

  14. RF cavity using liquid dielectric for tuning and cooling

    DOE Patents [OSTI]

    Popovic, Milorad (Warrenville, IL); Johnson, Rolland P. (Newport News, VA)

    2012-04-17

    A system for accelerating particles includes an RF cavity that contains a ferrite core and a liquid dielectric. Characteristics of the ferrite core and the liquid dielectric, among other factors, determine the resonant frequency of the RF cavity. The liquid dielectric is circulated to cool the ferrite core during the operation of the system.

  15. Booster Synchrotron RF System Upgrade for SPEAR3

    SciTech Connect (OSTI)

    Park, Sanghyun; Corbett, Jeff; /SLAC

    2012-07-06

    Recent progress at the SPEAR3 includes the increase in stored current from 100 mA to 200 mA and top-off injection to allow beamlines to stay open during injection. Presently the booster injects 3.0 GeV beam to SPEAR3 three times a day. The stored beam decays to about 150 mA between the injections. The growing user demands are to increase the stored current to the design value of 500 mA, and to maintain it at a constant value within a percent or so. To achieve this goal the booster must inject once every few minutes. For improved injection efficiency, all RF systems at the linac, booster and SPEAR3 need to be phase-locked. The present booster RF system is basically a copy of the SPEAR2 RF system with 358.5 MHz and 40 kW peak RF power driving a 5-cell RF cavity for 1.0 MV gap voltage. These requirements entail a booster RF system upgrade to a scaled down version of the SPEAR3 RF system of 476.3 MHz with 1.2 MW cw klystron output power capabilities. We will analyze each subsystem option for their merits within budgetary and geometric space constraints. A substantial portion of the system will come from the decommissioned PEP-II RF stations.

  16. Dial It In: Rotating RF Sensors to Enhance Radio Tomography

    E-Print Network [OSTI]

    Patwari, Neal

    --A radio tomographic imaging (RTI) system uses the received signal strength (RSS) measured by RF sensors of the antenna of each RF sensor can dramatically affect imaging and localization performance of an RTI system in a deployed RTI system requires the deployer to iteratively "guess-and-retest", i.e., pick a sensor to move

  17. Beyond ITER: RF Heating and Current Drive Issues for DEMO

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    Current devices Need flexible RF systems for heating, CD, start-up, instability suppression, and profileBeyond ITER: RF Heating and Current Drive Issues for DEMO C. K. Phillips, J. C. Hosea, G. Taylor under development ­ May need Lower Hybrid for r/a > 0.6 (not currently on ITER) ­ Need feedback control

  18. Model Reduction for RF MEMS Simulation David S. Bindel1

    E-Print Network [OSTI]

    California at Davis, University of

    Model Reduction for RF MEMS Simulation David S. Bindel1 , Zhaojun Bai2 , and James W. Demmel3 1@eecs.berkeley.edu Abstract. Radio-frequency (RF) MEMS resonators, integrated into CMOS chips, are of great interest-preserving model-reduction techniques and apply them to the frequency-domain analysis of two proposed MEMS

  19. RF-MEMS capacitive switches with high reliability

    DOE Patents [OSTI]

    Goldsmith, Charles L.; Auciello, Orlando H.; Carlisle, John A.; Sampath, Suresh; Sumant, Anirudha V.; Carpick, Robert W.; Hwang, James; Mancini, Derrick C.; Gudeman, Chris

    2013-09-03

    A reliable long life RF-MEMS capacitive switch is provided with a dielectric layer comprising a "fast discharge diamond dielectric layer" and enabling rapid switch recovery, dielectric layer charging and discharging that is efficient and effective to enable RF-MEMS switch operation to greater than or equal to 100 billion cycles.

  20. Shielded RF Lattice for the Muon Front End Chris Rogers,

    E-Print Network [OSTI]

    McDonald, Kirk

    Shielded RF Lattice for the Muon Front End Chris Rogers, Accelerator Science and Technology Centre (ASTeC), Rutherford Appleton Laboratory #12; Shielded RF Lattice I wanted to remind folks a lot of slides apologies I've tried to break it up a bit #12; Part 1 Shielded Lattice Baseline

  1. Tunnel MOS Heterostructure Field Effect Transistor for RF Switching Applications 

    E-Print Network [OSTI]

    Rezanezhad Gatabi, Iman

    2013-06-06

    GaN RF switches are widely used in today’s communication systems. With digital communications getting more and more popular nowadays, the need for improving the performance of involved RF switches is inevitable. Designing low ON-state resistance Ga...

  2. Upgrade of the cryogenic CERN RF test facility

    SciTech Connect (OSTI)

    Pirotte, O.; Benda, V.; Brunner, O.; Inglese, V.; Maesen, P.; Vullierme, B.; Koettig, T.

    2014-01-29

    With the large number of superconducting radiofrequency (RF) cryomodules to be tested for the former LEP and the present LHC accelerator a RF test facility was erected early in the 1990’s in the largest cryogenic test facility at CERN located at Point 18. This facility consisted of four vertical test stands for single cavities and originally one and then two horizontal test benches for RF cryomodules operating at 4.5 K in saturated helium. CERN is presently working on the upgrade of its accelerator infrastructure, which requires new superconducting cavities operating below 2 K in saturated superfluid helium. Consequently, the RF test facility has been renewed in order to allow efficient cavity and cryomodule tests in superfluid helium and to improve its thermal performances. The new RF test facility is described and its performances are presented.

  3. Proposal for high pressure RF cavity test in the MTA

    SciTech Connect (OSTI)

    Yonehara, K.; /Fermilab

    2010-09-01

    In order to demonstrate the feasibility of high pressure hydrogen gas filled RF (HPRF) cavities for muon ionization cooling, an HPRF cavity must be tested with a high intensity charged beam. When an HPRF cavity is irradiated with an intense beam each incident particle generates about 1000 electrons and ions per cubic centimeter in a high pressure cavity via ionization. These ionization electrons are influenced by the RF field and the RF quality factor goes down. This Q factor reduction will be a problem with a multi bunch beam, e.g., a muon beam for a muon collider consists of a 12 to 20 bunch train beam with 5 ns timing gap. Thus, the RF field must recover in few nano seconds. We propose to use a 400 MeV proton beam in the MTA and measure a beam loading effect in the HPRF cavity and study the recovery mechanism of the RF field.

  4. Cold Test Measurements on the GTF Prototype RF Gun

    SciTech Connect (OSTI)

    Gierman, S.M.

    2010-12-03

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. Based on longitudinal phase space measurements showing a correlated energy spread the gun was removed and re-characterized in 2002. The low power RF measurements performed on the gun are described below. Perturbative bead measurements were performed to determine the field ratio in the two-cell gun, and network analyzer measurements were made to characterize the mode structure. A second probe was installed to monitor the RF field in the first cell, and a diagnostic was developed to monitor the high-power field ratio. Calibration of the RF probes, a model for analyzing RF measurements, and Superfish simulations of bead and RF measurements are described.

  5. Progress on a cryogenically cooled RF gun polarized electron source

    SciTech Connect (OSTI)

    Fliller, R.P., III; Edwards, H.; /Fermilab

    2006-08-01

    RF guns have proven useful in multiple accelerator applications. An RF gun capable of producing polarized electrons is an attractive electron source for the ILC or an electron-ion collider. Producing such a gun has proven elusive. The NEA GaAs photocathode needed for polarized electron production is damaged by the vacuum environment in an RF gun. Electron and ion back bombardment can also damage the cathode. These problems must be mitigated before producing an RF gun polarized electron source. In this paper we report continuing efforts to improve the vacuum environment in a normal conducting RF gun by cooling it with liquid nitrogen after a high temperature vacuum bake out. We also report on a design of a cathode preparation chamber to produce bulk GaAs photocathodes for testing in such a gun. Future directions are also discussed.

  6. RF-driven Proton Source with a Back-streaming Electron Dump

    E-Print Network [OSTI]

    Ji, Q.

    2010-01-01

    RESULTS A. Atomic ion fraction for RF power above 500 W. AtI, the atomic ion fraction increases with the RF power, and

  7. LHC RF System Time-Domain Simulation

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.

    2010-09-14

    Non-linear time-domain simulations have been developed for the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC). These simulations capture the dynamic behavior of the RF station-beam interaction and are structured to reproduce the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They are also a valuable tool for the study of diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Results from these studies and related measurements from PEP-II and LHC have been presented in multiple places. This report presents an example of the time-domain simulation implementation for the LHC.

  8. RF Power Generation in LINAC4

    E-Print Network [OSTI]

    Brunner, O; Schwerg, J N

    2010-01-01

    Linac4 is a lin­ear ac­cel­er­a­tor for neg­a­tive Hy­dro­gen ions (H-) which will re­place the old Linac2 as lin­ear in­jec­tor for the CERN ac­cel­er­a­tors. Its high­er en­er­gy of 160 MeV will give in­creased beam in­ten­si­ty in the down­stream ma­chines. Linac4 is about 100 m long, nor­mal-con­duct­ing, and will be housed in a tun­nel about 12 m below ground. The Linac4 tun­nel will be con­nect­ed to the ex­ist­ing chain of ac­cel­er­a­tors and can be ex­tend­ed to the new in­jec­tion chain. The high RF power for the Linac4 ac­cel­er­at­ing struc­tures will be gen­er­at­ed by thir­teen 1.3 MW klystrons, pre­vi­ous­ly used for the CERN LEP ac­cel­er­a­tor, and six new 2.8 MW klystrons of all op­er­at­ing at a fre­quen­cy of 352.2 MHz. The in­te­gra­tion of the RF power sys­tem in the build­ing is pre­sent­ed. The tech­ni­cal spec­i­fi­ca­tions and the per­for­mance of the var­i­ous high-pow­er el­e­ments are dis­cussed, ...

  9. The Walnut Street Model of Ionospheric HF Radio Propagation Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    1 The Walnut Street Model of Ionospheric HF Radio Propagation Eric E. Johnson New Mexico State on radio frequency, latitude, time of day, season, the solar weather, and so on. Signals reach the receiver

  10. LuHf isotope systematics of fossil biogenic apatite and their effects on geochronology

    E-Print Network [OSTI]

    Schöne, Bernd R.

    ) and argillaceous matrices with low permeability (oil shale of Messel, Germany; Posidonienschiefer of Holzmaden the Eifel, Germany. Low 176 Lu/177 Hf ratios in all materials from the Middle Eocene Messel oil shale (e

  11. HF beam parameters in ELF/VLF wave generation via modulated heating of the ionosphere

    E-Print Network [OSTI]

    of spreading the HF power over a wider area, and we find that a larger beam area yields larger generated et al., 1982], and the observa- tory at Jicamarca, Peru [Lunnen et al., 1984], were both used

  12. The mechanism of HF formation in LiPF6-based organic carbonate electrolytes

    E-Print Network [OSTI]

    Lux, Simon

    2014-01-01

    The mechanism of HF formation in LiPF6-based organicliterature data, a simplified mechanism for the formation of3 . In this proposed mechanism, the blue lines represent the

  13. THIRD-GENERATION TECHNOLOGIES FOR HF RADIO NETWORKING Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    THIRD-GENERATION TECHNOLOGIES FOR HF RADIO NETWORKING Eric E. Johnson New Mexico State University for Internet protocols and applications This new generation of open standards is the result of ideas

  14. STUDY OF THE REACTION DYNAMICS OF Li + HF, HC1 BY THE CROSSED MOLECULAR BEAMS METHOD

    E-Print Network [OSTI]

    Becker, Christopher H.

    2013-01-01

    the angular and velocity distributions of reaction products~of~flight velocity measurements of the reaction product atLi + HF reaction at EC 2.2 kcal/mole. Velocity distributions

  15. LHC Beam Diffusion Dependence on RF Noise: Models And Measurements

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Van Winkle, D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; ,

    2010-09-14

    Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

  16. Upgrading EMMA to Use Low-frequency RF Cavities

    SciTech Connect (OSTI)

    Ohmori, C.; Berg, J.

    2011-04-30

    EMMA is an experiment to study beam dynamics in fixed field alternating gradient accelerators (FFAGs). It accelerates the beam in about 10 turns using 1.3 GHz cavities in a mode like that used for muon accelerators. Many applications of FFAGs prefer to have slower acceleration, typically thousands of turns. To do so in EMMA would require the RF system to be replaced with a low-frequency, high-gradient system. This paper describes the motivation for studying slow acceleration in EMMA and the required parameters for an RF system to do that. It then describes the technology needed for the RF system.

  17. An RF dosimeter for independent SAR measurement in MRI scanners

    SciTech Connect (OSTI)

    Qian, Di; Bottomley, Paul A.; El-Sharkawy, AbdEl-Monem M.; Edelstein, William A.

    2013-12-15

    Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ?3%. With the torso landmarked at the xiphoid, human adult whole?body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average independent of the imaging subject, albeit with fluctuations. Conclusions: Our 3T RF dosimeter and transducers accurately measure RF exposure in body-equivalent loads and provide scanner-independent assessments of whole-body RF power deposition for establishing safety compliance useful for MRI sequence and device testing.

  18. Characterization of an RF plasma ion source for ion implantation

    SciTech Connect (OSTI)

    Kopalidis, Peter M.; Wan Zhimin

    2012-11-06

    A novel inductively coupled RF plasma ion source has been developed for use in a beamline ion implanter. Ion density data have been taken with an array of four Langmuir probes spaced equally at the source extraction arc slit. These provide ion density uniformity information as a function of source pressure, RF power and gas mixture composition. In addition, total extracted ion beam current data are presented for the same conditions. The comparative advantages of the RF source in terms of higher beam current, reduced maintenance and overall productivity improvement compared to a hot cathode source are discussed.

  19. Communication methods, systems, apparatus, and devices involving RF tag registration

    DOE Patents [OSTI]

    Burghard, Brion J. (W. Richland, WA); Skorpik, James R. (Kennewick, WA)

    2008-04-22

    One technique of the present invention includes a number of Radio Frequency (RF) tags that each have a different identifier. Information is broadcast to the tags from an RF tag interrogator. This information corresponds to a maximum quantity of tag response time slots that are available. This maximum quantity may be less than the total number of tags. The tags each select one of the time slots as a function of the information and a random number provided by each respective tag. The different identifiers are transmitted to the interrogator from at least a subset of the RF tags.

  20. RF-MEMS load sensors with enhanced Q-factor and sensitivity in a suspended architecture

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    RF-MEMS load sensors with enhanced Q-factor and sensitivity in a suspended architecture Rohat Melik-implant RF-MEMS a b s t r a c t In this paper, we present and demonstrate RF-MEMS load sensors designed the strain change in real-time. For this purpose, we present RF- MEMS resonator sensors that shift

  1. Microwave Laminate PCB Compatible RF MEMS Technology for Wireless Communication Systems

    E-Print Network [OSTI]

    De Flaviis, Franco

    Microwave Laminate PCB Compatible RF MEMS Technology for Wireless Communication Systems * Bedri A microwave laminate printed circuit board (PCB) compatible RF MEMS technology for wireless communication systems. This technology is novel in that RF MEMS components, particularly RF MEM switches, can

  2. Interdiffusion and Reaction between Zr and Al Alloys from 425 degrees to 625 degrees C

    SciTech Connect (OSTI)

    J. Dickson; L. Zhou; A. Ewh; M. Fu; D. D. Keiser, Jr.; Y. H. Sohn; A. Paz y Puente

    2014-06-01

    Zirconium has recently garnered attention for use as a diffusion barrier between U–Mo nuclear fuels and Al cladding alloys. Interdiffusion and reactions between Zr and Al, Al-2 wt.% Si, Al-5 wt.% Si or AA6061 were investigated using solid-to-solid diffusion couples annealed in the temperature range of 425 degrees to 625 degrees C. In the binary Al and Zr system, the Al3Zr and Al2Zr phases were identified, and the activation energy for the growth of the Al3Zr phase was determined to be 347 kJ/mol. Negligible diffusional interactions were observed for diffusion couples between Zr vs. Al-2 wt.% Si, Al-5 wt.% Si and AA6061 annealed at or below 475 degrees C. In diffusion couples with the binary Al–Si alloys at 560 degrees C, a significant variation in the development of the phase constituents was observed including the thick t1 (Al5SiZr2) with Si content up to 12 at.%, and thin layers of (Si,Al)2Zr, (Al,Si)3Zr, Al3SiZr2 and Al2Zr phases. The use of AA6061 as a terminal alloy resulted in the development of both T1 (Al5SiZr2) and (Al,Si)3Zr phases with a very thin layer of (Al,Si)2Zr. At 560 degrees C, with increasing Si content in the Al–Si alloy, an increase in the overall rate of diffusional interaction was observed; however, the diffusional interaction of Zr in contact with multicomponent AA6061 with 0.4–0.8 wt.% Si was most rapid.

  3. RF Thermal Plasma Synthesis of Ferrite Nanopowders from Metallurgical Wastes

    E-Print Network [OSTI]

    Gubicza, Jenõ

    that of ferrites synthesized by the conventional ceramic route. Introduction Radiofrequency (RF) thermal plasmas by X-ray diffraction (XRD) using a Philips Xpert diffractometer and CuK radiation (=0.15418 nm

  4. Electrical degradation mechanisms of RF power GaAs PHEMTs

    E-Print Network [OSTI]

    Villanueva, Anita A. (Anita Ariel), 1978-

    2007-01-01

    GaAs Pseudomorphic High-Electron Mobility Transistors (PHEMTs) are widely used in RF power applications. Since these devices typically operate at high power levels and under high voltage biasing, their electrical reliability ...

  5. Possible high power limitations from RF pulsed heating

    SciTech Connect (OSTI)

    Pritzkau, D.P.; Bowden, G.B.; Menegat, A.; Siemann, R.H. [Stanford Linear Accelerator Center, Stanford University, California 94309 (United States)

    1999-05-01

    One of the possible limitations to achieving high power in RF structures is damage to metal surfaces due to RF pulsed heating. Such damage may lead to degradation of RF performance. An experiment to study RF pulsed heating on copper has been developed at SLAC. The experiment consists of operating two pillbox cavities in the TE{sub 011} mode using a 50 MW X-Band klystron. The estimated temperature rise of the surface of copper is 350&hthinsp;{degree}C for a power input of 20 MW to each cavity with a pulse length of 1.5 {mu}s. Preliminary results from an experiment performed earlier are presented. A revised design for continued experiments is also presented along with relevant theory and calculations. {copyright} {ital 1999 American Institute of Physics.}

  6. Efficiency enhancement techniques for RF and millimeter wave power amplifiers

    E-Print Network [OSTI]

    Ogunnika, Olumuyiwa Temitope, 1978-

    2012-01-01

    Power amplifiers are the circuit blocks in wireless transceivers that require the largest power budget because of their relatively low efficiencies. RF designers cannot depend solely on the development better semiconductor ...

  7. Klystron "efficiency loop" for the ALS storage ring RF system

    E-Print Network [OSTI]

    Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

    2002-01-01

    to Mod, Feb. 7, 2002] SRRF Klystron Beam Current (A) [AfterTime (hrs) Figure 2: SRRF Klystron Efficiency Comparison forKLYSTRON “EFFICIENCY LOOP” FOR THE ALS STORAGE RING RF

  8. Superfluid helium cryogenic systems for superconducting RF cavities...

    Office of Scientific and Technical Information (OSTI)

    (STF) for R and D of the International Linear Collider (ILC) project and the compact Energy Recovery Linac (cERL), employ superconducting RF cavities made of pure niobium,...

  9. Recent Progress of RF Cavity Study at Mucool Test Area

    SciTech Connect (OSTI)

    Yonehara, Katsuya; /Fermilab

    2011-12-02

    Summar of presentation is: (1) MTA is a multi task working space to investigate RF cavities for R&D of muon beam cooling channel - (a) Intense 400 MeV H{sup -} beam, (b) Handle hydrogen (flammable) gas, (c) 5 Tesla SC solenoid magnet, (d) He cryogenic/recycling system; (2) Pillbox cavity has been refurbished to search better RF material - Beryllium button test will be happened soon; (3) E x B effect has been tested in a box cavity - Under study (result seems not to be desirable); (4) 201 MHz RF cavity with SRF cavity treatment has been tested at low magnetic field - (a) Observed some B field effect on maximum field gradient and (b) Further study is needed (large bore SC magnet will be delivered end of 2011); and (5) HPRF cavity beam test has started - (a) No RF breakdown observed and (b) Design a new HPRF cavity to investigate more plasma loading effect.

  10. RADIATION SOLID STATE PHYSICS R.F. Konopleva

    E-Print Network [OSTI]

    Titov, Anatoly

    233 RADIATION SOLID STATE PHYSICS R.F. Konopleva The development of the nuclear and nuclear fusion, and the thermonuclear devices. In this connection the "Laboratory of the non-equilibrium electronic processes

  11. BN/Graphene/BN Transistors for RF Applications

    E-Print Network [OSTI]

    Taychatanapat, Thiti

    In this letter, we demonstrate the first BN/graphene/BN field-effect transistor for RF applications. This device structure can preserve the high mobility and the high carrier velocity of graphene, even when it is sandwiched ...

  12. Frequency and amplitude control for an experimental linac rf drive 

    E-Print Network [OSTI]

    Atre, Mahesh Purushottam

    1992-01-01

    FREQUENCY AND AMPLITUDE CONTROL FOR AN EXPERIMENTAL LINAC RF DRIVE A Thesis by MAHESH PURUSHOTTAM ATRE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1992 Major Subject: Electrical Engineering FREQUENCY AND AMPLITUDE CONTROL FOR AN EXPERIMENTAL LINAC RF DRIVE A Thesis by MAHESH PURUSHOTTAM ATRE Approved as to style and content by: S. P. Bhattachary (Chair of Committee) arng Huang...

  13. Measurement of current distribution on RF coils using MR imaging 

    E-Print Network [OSTI]

    Wu, Yu

    1993-01-01

    MEASUREMENT OF CURRENT DISTRIBUTION ON RF COILS USING MR IMAGING A Thesis by YU WU Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December... 1993 Major Subject' Electrical Engineering MEASUREMENT OF CURRENT DISTRIBUTION ON RF COILS USING MR IMAGING A Thesis by YU WU Submitted to Texas ASM University in partial fulfillment of the requirments for the degree of MASTER OF SCIENCE...

  14. DOE planning workshop on rf theory and computations

    SciTech Connect (OSTI)

    Not Available

    1984-01-01

    The purpose of the two-day workshop-meeting was to review the status of rf heating in magnetic fusion plasmas and to determine the outstanding problems in this area. The term rf heating was understood to encompass not only bulk plasma heating by externally applied electromagnetic power but also current generation in toroidal plasmas and generation of thermal barriers in tandem mirror plasmas.

  15. Handbook for Gas Filled RF Cavity Aficionados'

    SciTech Connect (OSTI)

    Tollestrup, A.V.; Chung, Moses; Yonehara, Katsuya; /Fermilab

    2009-05-01

    The use of hydrogen gas filled RF cavities in muon cooling channels has been proposed by Rolland Johnson. Impressive results have been obtained toward attaining high voltage gradients and rapid training in preliminary tests done at the FNAL MTA facility. However, so far it has not been possible to test them under conditions where they were subject to the transversal of a high intensity particle beam. This note is an attempt to bring together a description of some of the pertinent physical processes that take place in the dilute plasma that is generated in the hydrogen gas by the beam. Two effects dominate. The first is that the free electrons generated can load down the cavity and transfer its energy to heating the gas. The second is a question of what happens to the plasma in the longer term. There is an enormous literature on the subject of the subject of dilute hydrogen plasmas and we can tap into this information in order to understand and predict the behavior of the cavity.

  16. Solid-Solution Nanoparticles: Use of a Nonhydrolytic Sol-Gel Synthesis To Prepare HfO2 and HfxZr1-xO2

    E-Print Network [OSTI]

    and Applied Mathematics, and Materials Research Science and Engineering Center, Columbia University, New York ( hafnia 30, zirconia 25), high melting points (2758 and 2700 °C, respectively), and great chemical. Hafnia and zirconia in the bulk can each adopt three different, albeit related, crystal structures

  17. High power RF systems for the BNL ERL project

    SciTech Connect (OSTI)

    Zaltsman, A.; Lambiase, R.

    2011-03-28

    The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

  18. A New Environmentally Friendly AL/ZR-Based Clay Stabilizer 

    E-Print Network [OSTI]

    El-Monier, Ilham Abdallah

    2013-01-18

    tests showed that this new chemical was effective, and unlike previous Al-based and Zr-based stabilizers (hydroxy aluminum and zirconium oxychloride solutions), it did not dissolve in acids and worked very well up to 300oF. Stabilizer A proved...

  19. Neutron capture on {sup 94}Zr: Resonance parameters and Maxwellian-averaged cross sections

    SciTech Connect (OSTI)

    Tagliente, G. [Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); University of Gent (Belgium); Milazzo, P. M.; Fujii, K.; Abbondanno, U.; Belloni, F.; Moreau, C. [Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A. [CEA/Saclay-IRFU, Gif-sur-Yvette (France); Alvarez, H.; Duran, I.; Paradela, C. [Universidade de Santiago de Compostela (Spain); Alvarez-Velarde, F.; Cano-Ott, D.; Embid-Segura, M. [Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain)

    2011-07-15

    The neutron capture cross sections of the Zr isotopes play an important role in nucleosynthesis studies. The s-process reaction flow between the Fe seed and the heavier isotopes passes through the neutron magic nucleus {sup 90}Zr and through {sup 91,92,93,94}Zr, but only part of the flow extends to {sup 96}Zr because of the branching point at {sup 95}Zr. Apart from their effect on the s-process flow, the comparably small isotopic (n,{gamma}) cross sections make Zr also an interesting structural material for nuclear reactors. The {sup 94}Zr (n,{gamma}) cross section has been measured with high resolution at the spallation neutron source n{sub T}OF at CERN and resonance parameters are reported up to 60 keV neutron energy.

  20. Thermally-driven H interaction with HfO{sub 2} films deposited on Ge(100) and Si(100)

    SciTech Connect (OSTI)

    Soares, G. V. Feijó, T. O.; Baumvol, I. J. R.; Aguzzoli, C.; Krug, C.; Radtke, C.

    2014-01-27

    In the present work, we investigated the thermally-driven H incorporation in HfO{sub 2} films deposited on Si and Ge substrates. Two regimes for deuterium (D) uptake were identified, attributed to D bonded near the HfO{sub 2}/substrate interface region (at 300?°C) and through the whole HfO{sub 2} layer (400–600?°C). Films deposited on Si presented higher D amounts for all investigated temperatures, as well as, a higher resistance for D desorption. Moreover, HfO{sub 2} films underwent structural changes during annealings, influencing D incorporation. The semiconductor substrate plays a key role in this process.

  1. Crystallization of Zr2PdxCu(1-x) and Zr2NixCu(1-x) Metallic Glass

    SciTech Connect (OSTI)

    Min Xu

    2008-08-18

    One interesting aspect of rretallic glasses is the numerous instances of the deviation of the phase selection from the amorphous state to thermodynamically stable phases during the crystallization process. Their devitrification pathways allow us to study the relationship between the original amorphous structure and their crystalline counter parts. Among the various factors of phase selections, size and electronic effects have been most extensively studied. Elucidating the phase selection process of a glassy alloy will be helpful to fill in the puzzle of the changes from disordered to ordered structures. In this thesis, Two model Zr{sub 2}Pd{sub x}Cu{sub (1-x)} and Zr{sub 2}Ni{sub x}Cu{sub (1-x)} (x = 0, 0.25, 0.5, 0.75 and 1) glassy systems were investigated since: (1) All of the samples can be made into a homogenous metallic glass; (2) The atomic radii differ from Pd to Cu is by 11%, while Ni has nearly the identical atomic size compare to Cu. Moreover, Pd and Ni differ by only one valence electron from Cu. Thus, these systems are ideal to test the idea of the effects of electronic structure and size factors; (3) The small number of components in these pseudo binary systems readily lend themselves to theoretical modeling. Using high temperature X-ray diffraction {HTXRD) and thermal analysis, topological, size, electronic, bond and chemical distribution factors on crystallization selections in Zr{sub 2}Pd{sub x}Cu{sub (1-x)} and Zr{sub 2}Ni{sub x}Cu{sub (1-x)} metallic glass have been explored. All Zr{sub 2}Pd{sub x}Cu{sub (1-x)} compositions share the same Cu11b phase with different pathways of meta-stable, icosahedral quasicrystalline phase (i-phase), and C16 phase formations. The quasicrystal phase formation is topologically related to the increasing icosahedral short range order (SRO) with Pd content in Zr{sub 2}Pd{sub x}Cu{sub (1·x)} system. Meta-stable C16 phase is competitive with C11b phase at x = 0.5, which is dominated by electronic structure rather than size effects. Cu-rich and Ni-rich compositions in Zr{sub 2}Ni{sub x}Cu{sub (1-x)} trend to divitrify to C11b or C16 phases respectively. In the proposed pseudo binary phase diagram, the domain of C16, C11b and co-existence phases are mainly related with the topology in the amorphous structure and formation enthalpies of crystalline phases.

  2. RF-Plasma Source Commissioning in Indian Negative Ion Facility

    SciTech Connect (OSTI)

    Singh, M. J.; Bandyopadhyay, M.; Yadava, Ratnakar; Chakraborty, A. K. [ITER- India, Institute for Plasma Research, A-29, Sector 25, GIDC, Gandhinagar, Gujrat (India); Bansal, G.; Gahlaut, A.; Soni, J.; Kumar, Sunil; Pandya, K.; Parmar, K. G.; Sonara, J. [Institute for Plasma Research, Bhat Gandhinagar, Gujrat (India); Kraus, W.; Heinemann, B.; Riedl, R.; Obermayer, S.; Martens, C.; Franzen, P.; Fantz, U. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching (Germany)

    2011-09-26

    The Indian program of the RF based negative ion source has started off with the commissioning of ROBIN, the inductively coupled RF based negative ion source facility under establishment at Institute for Plasma research (IPR), India. The facility is being developed under a technology transfer agreement with IPP Garching. It consists of a single RF driver based beam source (BATMAN replica) coupled to a 100 kW, 1 MHz RF generator with a self excited oscillator, through a matching network, for plasma production and ion extraction and acceleration. The delivery of the RF generator and the RF plasma source without the accelerator, has enabled initiation of plasma production experiments. The recent experimental campaign has established the matching circuit parameters that result in plasma production with density in the range of 0.5-1x10{sup 18}/m{sup 3}, at operational gas pressures ranging between 0.4-1 Pa. Various configurations of the matching network have been experimented upon to obtain a stable operation of the set up for RF powers ranging between 25-85 kW and pulse lengths ranging between 4-20 s. It has been observed that the range of the parameters of the matching circuit, over which the frequency of the power supply is stable, is narrow and further experiments with increased number of turns in the coil are in the pipeline to see if the range can be widened. In this paper, the description of the experimental system and the commissioning data related to the optimisation of the various parameters of the matching network, to obtain stable plasma of required density, are presented and discussed.

  3. Electric-field gradients at the Zr sites in Zr3Fe: Measured using perturbed-angular-correlation spectroscopy and calculated using band theory

    E-Print Network [OSTI]

    Motta, Arthur T.

    Electric-field gradients at the Zr sites in Zr3Fe: Measured using perturbed-angular-correlation spectroscopy and calculated using band theory Arthur T. Motta, Stephen E. Cumblidge, and Gary L. Catchen; published 13 December 2001 We have measured the electric-field-gradient EFG parameters VZZ

  4. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 4, AUGUST 2006 1105 A Study of ZrN/Zr Coatings Deposited on

    E-Print Network [OSTI]

    Zheng, Yufeng

    IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 4, AUGUST 2006 1105 A Study of ZrN/Zr Coatings/metal coatings were deposited onto NiTi shape-memory alloy using plasma immersion ion im- plantation, such as unbalanced magnetron sputtering, ion plat- ing, ion-beam-assisted deposition, cathodic-vacuum-arc evapo

  5. High Power RF Test Facility at the SNS

    SciTech Connect (OSTI)

    Y.W. Kang; D.E. Anderson; I.E. Campisi; M. Champion; M.T. Crofford; R.E. Fuja; P.A. Gurd; S. Hasan; K.-U. Kasemir; M.P. McCarthy; D. Stout; J.Y. Tang; A.V. Vassioutchenko; M. Wezensky; G.K. Davis; M. A. Drury; T. Powers; M. Stirbet

    2005-05-16

    RF Test Facility has been completed in the SNS project at ORNL to support test and conditioning operation of RF subsystems and components. The system consists of two transmitters for two klystrons powered by a common high voltage pulsed converter modulator that can provide power to two independent RF systems. The waveguides are configured with WR2100 and WR1150 sizes for presently used frequencies: 402.5 MHz and 805 MHz. Both 402.5 MHz and 805 MHz systems have circulator protected klystrons that can be powered by the modulator capable of delivering 11 MW peak and 1 MW average power. The facility has been equipped with computer control for various RF processing and complete dual frequency operation. More than forty 805 MHz fundamental power couplers for the SNS superconducting linac (SCL) cavities have been RF conditioned in this facility. The facility provides more than 1000 ft2 floor area for various test setups. The facility also has a shielded cave area that can support high power tests of normal conducting and superconducting accelerating cavities and components.

  6. RF Power Upgrade for CEBAF at Jefferson Laboratory

    SciTech Connect (OSTI)

    Andrew Kimber,Richard Nelson

    2011-03-01

    Jefferson Laboratory (JLab) is currently upgrading the 6GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12GeV. As part of the upgrade, RF systems will be added, bringing the total from 340 to 420. Existing RF systems can provide up to 6.5 kW of CW RF at 1497 MHZ. The 80 new systems will provide increased RF power of up to 13 kW CW each. Built around a newly designed and higher efficiency 13 kW klystron developed for JLab by L-3 Communications, each new RF chain is a completely revamped system using hardware different than our present installations. This paper will discuss the main components of the new systems including the 13 kW klystron, waveguide isolator, and HV power supply using switch-mode technology. Methodology for selection of the various components and results of initial testing will also be addressed. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

  7. A 12 GHz RF Power Source for the CLIC Study

    SciTech Connect (OSTI)

    Schirm, Karl; /CERN; Curt, Stephane; /CERN; Dobert, Steffen; /CERN; McMonagle, Gerard; /CERN; Rossat, Ghislain; /CERN; Syratchev, Igor; /CERN; Timeo, Luca; /CERN; Haase, Andrew /SLAC; Jensen, Aaron; /SLAC; Jongewaard, Erik; /SLAC; Nantista, Christopher; /SLAC; Sprehn, Daryl; /SLAC; Vlieks, Arnold; /SLAC; Hamdi, Abdallah; /Saclay; Peauger, Franck; /Saclay; Kuzikov, Sergey; /Nizhnii Novgorod, IAP; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

    2012-07-03

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  8. Triaxial strongly deformed bands in {sup 164}Hf and the effect of elevated yrast line

    SciTech Connect (OSTI)

    Ma Wenchao

    2012-10-20

    Two exotic rotational bands have been identified in {sup 164}Hf and linked to known states. They are interpreted as being associated with the calculated triaxial strongly deformed (TSD) potential energy minimum. The bands are substantially stronger and are located at much lower spins than the previously discovered TSD bands in {sup 168}Hf. In addition to the proton and neutron shell gaps at large trixiality, it was proposed that the relative excitation energy of TSD bands above the yrast line plays an important role in the population of TSD bands.

  9. Klystron 'efficiency loop' for the ALS storage ring RF system

    SciTech Connect (OSTI)

    Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

    2002-05-20

    The recent energy crisis in California has led us to investigate the high power RF systems at the Advanced Light Source (ALS) in order to decrease the energy consumption and power costs. We found the Storage Ring Klystron Power Amplifier system operating as designed but with significant power waste. A simple proportional-integrator (PI) analog loop, which controls the klystron collector beam current, as a function of the output RF power, has been designed and installed. The design considerations, besides efficiency improvement, were to interface to the existing system without major expense. They were to also avoid the klystron cathode power supply filter's resonance in the loop's dynamics, and prevent a conflict with the existing Cavity RF Amplitude Loop dynamics. This efficiency loop will allow us to save up to 700 MW-hours of electrical energy per year and increase the lifetime of the klystron.

  10. Adaptive RF Transient Reduction for HIGH Intensity Beams with Gaps

    E-Print Network [OSTI]

    Tückmantel, Joachim

    2006-01-01

    When a high-intensity beam with bunch-trains and gaps passes a cavity with a high-gain vector feedback enforcing a constant voltage, large transients appear, stressing the RF high power hardware and increasing the trip rate. By modulating the cavity voltage with a varying periodic waveform (set-function), the RF power can be made constant while still preserving the high feedback gain. The average cavity voltage is conserved but bunches have to settle at slightly shifted positions. A method is derived to obtain this set-function in practice while making no assumptions or measurements of the beam or RF parameters. Adiabatic iterations are made including the whole machine as an analog computing device, using all parameters as they are. A computer simulation shows the success of the method.

  11. In situ RF/microwave remediation of soil experiment overview

    SciTech Connect (OSTI)

    Regan, A.H.; Palomares, M.E.; Polston, C.; Rees, D.E.; Roybal, W.T. [Los Alamos National Lab., NM (United States); Ross, T.J. [Univ. of New Mexico, Albuquerque, NM (United States)

    1995-09-01

    Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors are developing an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently, the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The authors objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants.

  12. Hydrocarbon reaction with HF-cleaned Si(lOQ) and effects on metal-oxide-semiconductor device quality

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Hydrocarbon reaction with HF-cleaned Si(lOQ) and effects on metal-oxide-semiconductor device-cleaned Si( 100) towards hydrocarbon adsorption is examined by surface analysis; most hydrocarbons adsorb oxidation after HF treatment.4'5 In this letter, passivation against hydrocarbon contamination is studied

  13. Coating power RF components with TiN

    SciTech Connect (OSTI)

    Kuchnir, M.; Hahn, E.

    1995-03-01

    A facility for coating RF power components with thin films of Ti and/or TiN has been in operation for some time at Fermilab supporting the Accelerator Division RF development work and the TESLA program. It has been experimentally verified that such coatings improve the performance of these components as far as withstanding higher electric fields. This is attributed to a reduction in the secondary electron emission coefficient of the surfaces when coated with a thin film containing titanium. The purpose of this Technical Memorandum is to describe the facility and the procedure used.

  14. CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN

    E-Print Network [OSTI]

    Chattopadhyay, S.

    2010-01-01

    Photocathode RF Electron Gun S. Chattopadhyay, Y.J. Chen, D.PHOTOCATHODE RF ELECTRON GUN' S. Chnttopndhyny. Y.J. Chen (Photocathode RF Electron Gun S. Chattopadhyay, Y.I. Chen, D.

  15. High linearity 1.5-2.5 GHz RF-MEMS and varactor diodes based tunable filters for wireless applications

    E-Print Network [OSTI]

    El-Tanani, Mohammed Ahmed

    2009-01-01

    5.2.3 RF-MEMS Tunable Capacitive Network . . . . . . . .5.3Wide-Bandwidth Miniaturized RF-MEMS Tun- ableApplications104 Appendix B RF MEMS Cantilever Fabrication

  16. Comparison of electromagnetic, thermal and mechanical calculations with rf test results in rf-dipole deflecting/crabbing cavities

    SciTech Connect (OSTI)

    Park, HyeKyoung [JLAB, ODU; De Silva, Subashini U. [ODU; Delayen, Jean R. [ODU, JLAB

    2013-12-01

    The current requirements of higher gradients and strict dimensional constraints in the emerging applications have required the designing of compact deflecting and crabbing rf structures. The superconducting rf-dipole cavity is one of the first novel compact designs with attractive properties such as higher gradients, higher shunt impedance and widely separated higher order modes. The recent tests performed on proof-of-principle designs of the rf-dipole geometry at 4.2 K and 2.0 K in the vertical test area at Jefferson Lab have proven the designs to achieve higher gradients with higher intrinsic quality factors and easily processed multipacting conditions. The cavity characteristics, such as pressure sensitivity and Lorentz force detuning, were studied using ANSYS before the fabrication. These characteristics were measured during the cavity test. The comparison between the simulation and the measurement provides insight how the simulation can be used for design and fabrication of future cavities.

  17. Radiation damage in cubic-ZrO2 and yttria-stabilized zirconia from molecular dynamics simulations

    SciTech Connect (OSTI)

    Aidhy, Dilpuneet S; Zhang, Yanwen; Weber, William J

    2015-01-01

    We perform molecular dynamics simulation on cubic ZrO2 and yttria-stabilized zirconia (YSZ) to elucidate defect cluster formation resulting from radiation damage, and evaluate the impact of Y-dopants. Interstitial clusters composed of split-interstitial building blocks, i.e., Zr-Zr or Y-Zr are formed. Oxygen vacancies control cation defect migration; in their presence, Zr interstitials aggregate to form split-interstitials whereas in their absence Zr interstitials remain immobile, as isolated single-interstitials. Y-doping prevents interstitial cluster formation due to sequestration of oxygen vacancies.

  18. http://znaturforsch.com/IEO/B302.pdf Compression Behavior of Zr-doped Nanoanatase

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    -pressure, Nanocrystals, Titania, Zirconia, Anatase, Dopant Introduction Titania TiO2, zirconia ZrO2, as well as zirconium

  19. Microstructural studies on cast Zr[sub 3]Al-3wt%Nb

    SciTech Connect (OSTI)

    Tewari, R.; Dey, G.K.; Mukhopadhyay, P.; Banerjee, S. . Metallurgy Div.)

    1994-05-01

    In the binary Zr-Al system, Zr[sub 3]Al is the intermetallic phase richest in zirconium. In view of its low absorption cross section for thermal neutrons and its good strength and corrosion resistance, Zr[sub 3]Al may have possible applications as a structural material in thermal reactors. This phase has the ordered cubic L1[sub 2] structure and forms through the peritectoid reaction: [beta]-Zr + Zr[sub 2]Al[minus] > Zr[sub 3]Al, the reaction temperature being 1,292 K. Structurally Zr[sub 3]Al is quite similar to the [alpha][sub 2] or the Ti[sub 3]Al phase (ordered hexagonal DO[sub 19] structure) in the Ti-Al system, the two structures differing only in the stacking sequence of the close packed atomic layers. But for its inherent brittleness, Ti[sub 3]Al is a promising structural material for aerospace applications. It has, however, been demonstrated that niobium additions can reduce the brittleness of this phase. Studies on the Ti[sub 3]Al-Nb system have also shown that niobium stabilizes the high temperature [beta] phase (bcc structure) which, on cooling, can decompose through various phase reactions, generating some interesting microstructures. Similar studies on the Zr[sub 3]Al-Nb system have not been reported yet. The present paper describes some microstructural observations made on a cast Zr[sub 3]Al-3wt%Nb alloy.

  20. Automatic Calibrations for Improved Quality Assurance of Coastal HF Radar Currents

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    to the public via the U.S. Integrated Ocean Observing System (USIOOS): http://www.ioos.gov/hfradar/. These real Monitoring, Monitoring Harmful Algal Blooms, Fisheries Management, Modeling, Marine Navigation, Ocean Energy. INTRODUCTION Currently, over 130 HF radar units are providing coastal surface current maps to the public via

  1. HF Multiresonant Electronic Ballast for Fluorescent Lamps with Constant Filament Preheat Voltage

    E-Print Network [OSTI]

    HF Multiresonant Electronic Ballast for Fluorescent Lamps with Constant Filament Preheat Voltage resonance arrangement that acts as a current source. During warm up the filaments are driven by a secondary the filament and shorts out the voltage across the lamp. Simulation and experimental results suggest

  2. Adsorbate shape selectivity: Separation of the HF/134a azeotrope over carbogenic molecular sieve

    SciTech Connect (OSTI)

    Hong, A.; Mariwala, R.K.; Kane, M.S.; Foley, H.C. [Univ. of Delaware, Nework, DE (United States)

    1995-03-01

    Experimental evidence is provided for adsorptive shape selectivity in the separation of the azeotrope between HF and 1,1,1,2-tetrafluoroethane (134a) over pyrolyzed poly(furfuryl alcohol)-derived carbogenic molecular sieve (PPFA-CMS). The separation can be accomplished over coconut charcoal or Carbosieve G on the basis of the differences in the extent of equilibrium adsorption of HF and 134a. On these adsorbents 134a is more strongly bound than HF, thus it elutes much more slowly from the bed. The heat of adsorption for 134a in the vicinity of 200 C on Carbosieve G is {approximately}8.8 kcal/mol. In contrast, when the same azeotropic mixture is separated over PPFA-CMS prepared at 500 C, 134a is not adsorbed. As a result 134a elutes from the bed first, followed by HF. The reversal is brought about by the narrower pore size and pore size distribution of the PPFA-CMS versus that for Carbosieve G. Thus the separation over PPFA-CMS is an example of adsorbate shape selectivity and represents a limiting case of kinetic separation.

  3. INTEROPERABILITY AND PERFORMANCE ISSUES IN HF E-MAIL Eric E. Johnson

    E-Print Network [OSTI]

    Johnson, Eric E.

    INTEROPERABILITY AND PERFORMANCE ISSUES IN HF E-MAIL Eric E. Johnson New Mexico State University exceed those experi- enced in the wired Internet. Beyond the delays imposed by low data bandwidths network.) · The Simple Mail Transfer Protocol SMTP [RFC-821] is the standard within the Internet. Its

  4. Comparing the performance of plasma impedance probes and Langmuir probes for RF plasma diagnostics

    E-Print Network [OSTI]

    Walker, Mitchell

    conducted in a 14-ft diameter, 22-ft long diffusion-pumped vacuum chamber. Plasma was produced waves via RF heating. Results Conclusions For the discharge plasma condition, there was a significant hybrid frequency. RF Ca

  5. 1 Filter_Supplemental-Info_090913.doc Supplemental Information Regarding RF/Microwave Filter Design

    E-Print Network [OSTI]

    Weller/USF 1 Filter_Supplemental-Info_090913.doc Supplemental Information Regarding RF/Microwave Filter Design The video module on RF/microwave filter design, Filter Demonstration in Microwave Office

  6. Investigation of RF-enhanced plasma potentials on Alcator C-Mod

    E-Print Network [OSTI]

    Cziegler, I.

    Radio frequency (RF) sheath rectification is a leading mechanism suspected of causing anomalously high erosion of plasma facing materials in RF-heated plasmas on Alcator C-Mod. An extensive experimental survey of the plasma ...

  7. Inkjet-Printed Ferromagnetic Nanoparticles for Miniaturization of Flexible Printed RF Inductors

    E-Print Network [OSTI]

    Tentzeris, Manos

    the inductor for flexible printed electronics. This flexible, miniaturized inductor can be coupledInkjet-Printed Ferromagnetic Nanoparticles for Miniaturization of Flexible Printed RF Inductors to apply ferromagnetic nanomaterial is investigated to produce a truly flexible, printed RF inductor

  8. Advances in Filter Miniaturization and Design/Analysis of RF MEMS Tunable Filters 

    E-Print Network [OSTI]

    Sekar, Vikram

    2012-10-19

    The main purpose of this dissertation was to address key issues in the design and analysis of RF/microwave filters for wireless applications. Since RF/microwave filters are one of the bulkiest parts of communication systems, their miniaturization...

  9. Timing and RF Synchrotronization for Filling PEP/SPEAR with the SLC Damping Rings

    E-Print Network [OSTI]

    Ronan, M.T.

    2011-01-01

    respect to the beam and the Klystron 2.856 GHz RF over theto 2.856 GHz by the Klystron subboosters. A fiducialop- erating at lhe IlDac Klystron RF frequency (2.856 GHz)

  10. High performance RF MEMS metal-contact switches and switching networks

    E-Print Network [OSTI]

    Patel, Chirag D.; Patel, Chirag D.

    2012-01-01

    applications,” in Microelectromechanical Systems Conference,force microscopy,” Microelectromechanical Systems, JournalRF applications,” Microelectromechanical Systems, Journal

  11. RF power potential of 45 nm CMOS technology

    E-Print Network [OSTI]

    Putnam, Christopher

    This paper presents the first measurements of the RF power performance of 45 nm CMOS devices with varying device widths and layouts. We find that 45 nm CMOS can deliver a peak output power density of around 140 mW/mm with ...

  12. Development of RF CMOS receiver front-ends for ultrawideband 

    E-Print Network [OSTI]

    Guan, Xin

    2009-05-15

    .5dB and a noise figure of 3.3-4.5dB from 3-9.5GHz, while only consuming 9mW power. Based on the distributed amplifier and resistive shunt-feedback amplifier designs, two UWB RF front-ends are developed. One is a distributed LNA-Mixer. Unlike...

  13. rf testbed for thermoacoustic tomography D. Fallon,1

    E-Print Network [OSTI]

    Hanson, George

    rf testbed for thermoacoustic tomography D. Fallon,1 L. Yan,2 G. W. Hanson,3 and S. K. Patch4,a 1 Received 28 October 2008; accepted 22 April 2009; published online 9 June 2009 Thermoacoustic signal is a preferred acoustic coupling medium for thermoacoustics because acoustic and electromagnetic waves propagate

  14. Sifting Through the Airwaves: Efficient and Scalable Multiband RF Harvesting

    E-Print Network [OSTI]

    Washington at Seattle, University of

    option. Compared to solar power, ambient RF has the advantage of being available at night starved of its energy source the device must cease to operate, limiting the application space mostly wideband harvesting can capture energy across a large swath of spectrum, it typically results in very low

  15. RF sputtered piezoelectric zinc oxide thin film for transducer applications

    E-Print Network [OSTI]

    Tang, William C

    parameters that could influence the quality of the resulting films include RF power, the ratio of argon depen- dency of the c-axis zinc oxide growth in radio-frequency sputtering system. Different deposition on the piezoelectric and crystalline qualities of the ZnO thin films. Experimental results showed that the multilayer

  16. EE 402 Microwave and RF Circuits Aqeel Ahmad Qureshi

    E-Print Network [OSTI]

    Saskatchewan, University of

    EE 402 Microwave and RF Circuits Aqeel Ahmad Qureshi aqeel.ahmad@usask.ca Objective: There is currently an explosion in wireless communications at microwave and millimeter-wave frequencies, for both-effective and highly integrated devices and circuits are required. An understanding of modern microwave theory

  17. LWA Equipment RF Emissions: Spectrum Analyzers and Ylva Pihlstrm, UNM

    E-Print Network [OSTI]

    Ellingson, Steven W.

    1 LWA Equipment RF Emissions: Spectrum Analyzers and Laptops Ylva Pihlström, UNM 8/27/06 Summary I be used at the LWDA site during standard VLA operations. Two brands of spectrum analyzers and laptop are therefore considered typical of spectrum analyzers and laptops. The results of the measurements suggest

  18. Klystron based high power rf system for proton accelerator

    SciTech Connect (OSTI)

    Pande, Manjiri; Shrotriya, Sandip; Sharma, Sonal; Patel, Niranjan; Handu, Verander, E-mail: manjiri@barc.gov.in, E-mail: manjiri08@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai (India)

    2011-07-01

    As a part of ADS program a proton accelerator (20 MeV, 30 mA) and its high power RF systems (HPRF) are being developed in BARC. This paper explains design details of this klystron based HPRF system. (author)

  19. Supply Chain Planning Analyst 4 Optical Components /RF Products

    E-Print Network [OSTI]

    Heller, Barbara

    Supply Chain Planning Analyst 4 Optical Components /RF Products Job Number: 82686511 Company Name to apply internal investment to improve their position in meeting current and future NGES sourcing needs, executing the plans put forth by the domain team. Minimum US citizen with ability to obtain DoD Secret

  20. In situ RF/microwave remediation of soil experiment overview

    SciTech Connect (OSTI)

    Regan, A.H.; Roybal, W.T.; Ortega, R.; Palomares, M.; Rees, D.E.; Tischler, D.

    1996-06-01

    Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors have developed an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants. The authors have conducted a number of benchtop experiments involving RF/microwave energy deposition and vapor extraction on controlled contaminated soil samples with successful removal of the contaminants. This paper will describe the experimental hardware utilized, the experiments performed, the chemical analysis performed pre- and post-energy application, and results. In the experiments, two different halogenated liquids were used to contaminate the soil: carbon tetrachloride and 1,1,1-trichloroethane.

  1. Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low-Loss Spacer

    E-Print Network [OSTI]

    Technische Universiteit Delft

    Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low-Loss Spacer Substrate Alexander Polyakov #12;#12;Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low ICs...............................................13 1.4. Wafer-level packaging for RF applications

  2. Evidence that global processing does not limit thresholds for RF shape discrimination

    E-Print Network [OSTI]

    Mullen, Kathy T.

    Evidence that global processing does not limit thresholds for RF shape discrimination McGill Vision whether shape discrimination thresholds for radial frequency (RF) patterns are limited at this global.75­6 cpd). First, we show using sections of an RF4 that shape discrimination thresholds are invariant

  3. Performance Analysis of Simultaneous Wireless Information and Power Transfer with Ambient RF

    E-Print Network [OSTI]

    Privault, Nicolas

    isotropic wireless power, and reception of the power by converting the harvested RF waves into electricity. INTRODUCTION RF energy harvesting techniques have evolved as a promis- ing and cost-effective solutionPerformance Analysis of Simultaneous Wireless Information and Power Transfer with Ambient RF Energy

  4. Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control

    E-Print Network [OSTI]

    Tentzeris, Manos

    Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control Ryo (WSN) that are solely powered by ambient RF power. Different from all other energy harvesting WSN systems, RF powered systems present a new challenge for the energy management. A WSN node repeatedly

  5. RF-MEMS Capacitive Series Switches of CPW & MSL Configurations for Reconfigurable Antenna Application

    E-Print Network [OSTI]

    De Flaviis, Franco

    RF-MEMS Capacitive Series Switches of CPW & MSL Configurations for Reconfigurable Antenna, University of California Irvine, Irvine, CA, 92697 Abstract: The air-bridged RF-MEMS switches in single pole) and coplanar waveguide (CPW) structures. RF-MEMS series switches are monolithic fabricated in both transmission

  6. Modeling and Optimization of RF-MEMS Reconfigurable Tuners with Computationally Efficient Time-Domain Techniques

    E-Print Network [OSTI]

    Tentzeris, Manos

    Modeling and Optimization of RF-MEMS Reconfigurable Tuners with Computationally Efficient Time of Technology, Atlanta, GA 30332 2 Raytheon Company, Tucson AZ, 85734 Abstract -- Modern RF-MEMS device design methods in which the FDTD technique can be used to model a reconfigurable RF-MEMS tuner. A new method

  7. Low Cost RF MEMS Switches Fabricated on Microwave Laminate Printed Circuit Boards

    E-Print Network [OSTI]

    De Flaviis, Franco

    1 Low Cost RF MEMS Switches Fabricated on Microwave Laminate Printed Circuit Boards Hung-Pin Chang process for directly constructing RF MEMS capacitive switches has been developed on microwave laminate among components. Index Terms--RF MEMS switches, compressive molding planarization, high density

  8. Thermodynamic Modeling and Experimental Study of the Fe-Cr-Zr System

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Bei, Hongbin; Busby, Jeremy T

    2013-01-01

    Wide applications of zircaloys, stainless steels and their interactions in nuclear reactors require the knowledge on phase stability and thermodynamic property of the Fe-Cr-Zr system. This knowledge is also important to develop new Zr-contained Fe-Cr ferritic steels. This work aims at developing thermodynamic models for describing phase stability and thermodynamic property of the Fe-Cr-Zr system using the Calphad approach coupled with experimental study. Thermodynamic descriptions of the Fe-Cr and Cr-Zr systems were either directly adopted or slightly modified from literature. The Fe-Zr system has been remodeled to accommodate recent ab-initio calculation of formation enthalpies of various Fe-Zr compounds. Reliable ternary experimental data and thermodynamic models were mainly available in the Zr-rich region. Therefore, selected ternary alloys located in the vicinity of the eutectic valley of (Fe,Cr,Zr) and (Fe,Cr)2Zr laves phase in the Fe-rich region have been experimentally investigated in this study. Microstructure has been examined by using scanning electron microscope, energy-dispersive Xray spectroscopy and X-ray diffraction. These experimental results, along with the literature data were then used to develop thermodynamic models for phases in the Fe-Cr-Zr system. Calculated phase equilibria and thermodynamic properties of the ternary system yield satisfactory agreements with available experimental data, which gives the confidence to use these models as building blocks for developing a Zr, Fe and Cr contained multicomponent thermodynamic database for broader applications in nuclear reactors.

  9. Comparative Analysis of Carbon Plasma in Arc and RF Reactors

    SciTech Connect (OSTI)

    Todorovic-Markovic, B.; Markovic, Z.; Mohai, I.; Szepvolgyi, J.

    2004-12-01

    Results on studies of molecular spectra emitted in the initial stages of fullerene formation during the processing of graphite powder in induction RF reactor and evaporation of graphite electrodes in arc reactor are presented in this paper. It was found that C2 radicals were dominant molecular species in both plasmas. C2 radicals have an important role in the process of fullerene synthesis. The rotational-vibrational temperatures of C2 and CN species were calculated by fitting the experimental spectra to the simulated ones. The results of optical emission study of C2 radicals generated in carbon arc plasma have shown that rotational temperature of C2 species depends on carbon concentration and current intensity significantly. The optical emission study of induction RF plasma and SEM analysis of graphite powder before and after plasma treatment have shown that evaporation of the processed graphite powder depends on feed rate and composition of gas phase significantly. Based on the obtained results, it was concluded that in the plasma region CN radicals could be formed by the reaction of C2 species with atomic nitrogen at smaller loads. At larger feed rate of graphite powder, CN species were produced by surface reaction of the hot carbon particles with nitrogen atoms. The presence of nitrogen in induction RF plasma reduces the fullerene yield significantly. The fullerene yield obtained in two different reactors was: 13% in arc reactor and 4.1% in induction RF reactor. However, the fullerene production rate was higher in induction RF reactor-6.4 g/h versus 1.7 g/h in arc reactor.

  10. The RF power system for the SNS linac

    SciTech Connect (OSTI)

    Tallerico, P.J.; Reass, W.A.

    1998-12-31

    The initial goal of the SNS project is to produce a 1 MW average beam of protons with short pulse lengths onto a neutron-producing target. The objective of the SNS RF system is to generate 117 MW peak of pulsed 805 MHz microwave power with an accelerated beam pulse length of 1.04 ms at a 60 Hz repetition rate. The power system must be upgradeable in peak power to deliver 2 MW average power to the neutron target. The RF system also requires about 3 MW peak of RF power at 402.5 MHz, but that system is not discussed here. The design challenge is to produce an RF system at minimum cost, that is very reliable and economical to operate. The combination of long pulses and high repetition rates make conventional solutions, such as the pulse transformer and transmission line method, very expensive. The klystron, with a modulating anode, and 1.5 MW of peak output power is the baseline RF amplifier, an 56 are required in the baseline design. The authors discuss four power system configurations that are the candidates for the design. The baseline design is a floating-deck modulating anode system. A second power system being investigated is the fast-pulsed power supply, that can be turned on and off with a rise time of under 0.1 ms. This could eliminate the need for a modulator, and drastically reduce the energy storage requirements. A third idea is to use a pulse transformer with a series IGBT switch and a bouncer circuit on the primary side, as was done for the TESLA modulator. A fourth method is to use a series IGBT switch at high voltage, and not use a pulse transformer. The authors discuss the advantages and problems of these four types of power systems, but they emphasize the first two.

  11. Transitions of bandgap and built-in stress for sputtered HfZnO thin films after thermal treatments

    SciTech Connect (OSTI)

    Li, Chih-Hung; Chen, Jian-Zhang [Institute of Applied Mechanics, National Taiwan University, Taipei City 10617, Taiwan (China)] [Institute of Applied Mechanics, National Taiwan University, Taipei City 10617, Taiwan (China); Cheng, I-Chun [Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei City 10617, Taiwan (China)] [Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei City 10617, Taiwan (China)

    2013-08-28

    HfZnO thin films with various Hf contents are sputter-deposited on glass substrates from Hf{sub x}Zn{sub 1?x}O (x = 0, 2.5, 5, 7.5, and 10 at. %) targets at room temperature. The incorporation of Hf in the ZnO film leads to the amorphorization of the materials. The amorphous structures of high-Hf-content films remain after annealing at 600 °C for 30 min. The built-in stresses of as-deposited films are compressive. As the annealing temperature increases, the stresses are relaxed and even become tensile. The films exhibit a high transmission of 80% in the visible region. The optical bandgap increases with the Hf content, but it decreases with the annealing temperature. This can be attributed to the alteration of strain (stress) status in the films and atomic substitution. The reduction of bandgap partly results from the grain growth, which is due to the quantum confinement effect of the small grains. Hf doping increases the resistivity of ZnO owing to the disorder of the material structure and the higher bandgap, which result in more carrier traps and less thermally excited carriers in the conduction bands.

  12. Sub-barrier fusion of 32S+90,96Zr: semi-classical coupled-channels approach

    E-Print Network [OSTI]

    H. Q. Zhang; C. J. Lin; F. Yang; H. M. Jia; X. X. Xu; F. Jia; Z. D. Wu; S. T. Zhang; Z. H. Liu; A. Richard; C. Beck

    2010-05-05

    The fusion excitation functions have been measured with rather good accuracy for 32S+90Zr and 32S+96Zr near and below the Coulomb barrier. The sub-barrier cross sections for 32S+96Zr are much larger compared with 32S+90Zr. Semi-classical coupled-channels calculations including two-phonon excitations are capable to describe sub-barrier enhancement only for 32S+90Zr. The remaining disagreement for 32S+96Zr comes from the positive Q-value intermediate neutron transfers in this system. The comparison with 40Ca+96Zr suggests that couplings to the positive Q-value neutron transfer channels may play a role in the sub-barrier fusion enhancement. A rather simple model calculation taking neutron transfers into account is proposed to overcome the discrepancies of 32S+96Zr.

  13. Zr electrorefining process for the treatment of cladding hull waste in LiCl-KCl molten salts

    SciTech Connect (OSTI)

    Lee, Chang Hwa; Lee, You Lee; Jeon, Min Ku; Kang, Kweon Ho; Choi, Yong Taek; Park, Geun Il [Korea Atomic Energy Research Institute - KAERI, 989-111 Daeduk-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2013-07-01

    Zr electrorefining for the treatment of Zircaloy-4 cladding hull waste is demonstrated in LiCl-KCl-ZrCl{sub 4} molten salts. Although a Zr oxide layer thicker than 5 ?m strongly inhibits the Zr dissolution process, pre-treatment processes increases the dissolution kinetics. For 10 g-scale experiments, the purities of the recovered Zr were 99.54 wt.% and 99.74 wt.% for fresh and oxidized cladding tubes, respectively, with no electrical contact issue. The optimal condition for Zr electrorefining has been found to improve the morphological feature of the recovered Zr, which reduces the salt incorporation by examining the effect of the process parameters such as the ZrCl{sub 4} concentration and the applied potential.

  14. 688 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 13, NO. 4, AUGUST 2004 Zirconium Tungstate (ZrW2O8)-Based

    E-Print Network [OSTI]

    Talghader, Joseph J.

    688 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 13, NO. 4, AUGUST 2004 Zirconium Tungstate (Zr expansion, sputtering, thermal factors, thin film, zirconium tungstate (ZrW2O8). I. INTRODUCTION THERMAL

  15. THE JOURNAL OF CHEMICAL PHYSICS 135, 104303 (2011) The visible spectrum of zirconium dioxide, ZrO2

    E-Print Network [OSTI]

    Maier, John Paul

    2011-01-01

    THE JOURNAL OF CHEMICAL PHYSICS 135, 104303 (2011) The visible spectrum of zirconium dioxide, ZrO2; published online 8 September 2011) The electronic spectrum of a cold molecular beam of zirconium dioxide, Zr

  16. PHYSICAL REVIEW B 91, 085129 (2015) Structural, electronic and hyperfine characterization of pure and Ta-doped ZrSiO4

    E-Print Network [OSTI]

    Svane, Axel Torstein

    2015-01-01

    correlation (TDPAC) using (181 Hf )181 Ta as probe techniques are highly efficient in investigating zirconium

  17. High resolution gas phase infrared spectroscopy of the hydrogen bonded complex HCN---HF and its deuterated isotopic species 

    E-Print Network [OSTI]

    Jackson, Marc William

    1987-01-01

    Scan Over a Portion of the u6 Band 1 System of HCiV---HF 59 The Central Portion of the u6 Band of HCN- ? -HF 1 Showing the 3 Assignment of the Q-branch and a Portion of the P-branch 1 A Portion of the R-branch of the u6 Band of HCN---HF 60 10 A... region. Reported herein is the analysis of the rovibrational substructure of the ul(D-F), u2(C-D) and w3 (C=N) predissociating stretching vibrations of DCiV---DF. Numerous molecular constants were determined for these fundamentals along with a total...

  18. Properties of Porous TiNbZr Shape Memory Alloy Fabricated by Mechanical Alloying

    E-Print Network [OSTI]

    Zheng, Yufeng

    , with subsequent hot or cold rolling, were used to fabricate these Ni-free SMAs. There is no work related to powderNb-6Zr (at.%) shape memory alloys produced using elemental powders by means of mechanical alloying by adding ternary elements, including Molybdenum (Mo), Palladium (Pd), Tin (Sn), Zirconium (Zr), etc. Ping

  19. Phase formation in ZrFe multilayers: Effect of irradiation A. T. Motta

    E-Print Network [OSTI]

    Motta, Arthur T.

    Phase formation in Zr­Fe multilayers: Effect of irradiation A. T. Motta The Pennsylvania State Science Division, Argonne National Laboratory, Argonne, Illinois 60403 M. E. Bru¨ckmann, S. R. Teixeira a detailed in situ study of phase formation in Zr­Fe metallic multilayers using irradiation and thermal

  20. Local structures surrounding Zr in nanostructurally stabilized cubic zirconia: Structural origin of phase stability

    SciTech Connect (OSTI)

    Soo, Y. L.; Chen, P. J.; Huang, S. H.; Shiu, T. J.; Tsai, T. Y.; Chow, Y. H.; Lin, Y. C.; Weng, S. C.; Chang, S. L. [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Wang, G.; Cheung, C. L. [Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Sabirianov, R. F.; Mei, W. N. [Department of Physics, University of Nebraska at Omaha, Omaha, Nebraska 68182 (United States); Namavar, F.; Haider, H.; Garvin, K. L. [Department of Orthopaedics Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska 68198 (United States); Lee, J. F. [National Synchrotron Radiation Research Center, Hsinchu 30013, Taiwan (China); Lee, H. Y.; Chu, P. P. [Department of Chemistry, National Central University, Jhongli 32001, Taiwan (China)

    2008-12-01

    Local environment surrounding Zr atoms in the thin films of nanocrystalline zirconia (ZrO{sub 2}) has been investigated by using the extended x-ray absorption fine structure (EXAFS) technique. These films prepared by the ion beam assisted deposition exhibit long-range structural order of cubic phase and high hardness at room temperature without chemical stabilizers. The local structure around Zr probed by EXAFS indicates a cubic Zr sublattice with O atoms located on the nearest tetragonal sites with respect to the Zr central atoms, as well as highly disordered locations. Similar Zr local structure was also found in a ZrO{sub 2} nanocrystal sample prepared by a sol-gel method. Variations in local structures due to thermal annealing were observed and analyzed. Most importantly, our x-ray results provide direct experimental evidence for the existence of oxygen vacancies arising from local disorder and distortion of the oxygen sublattice in nanocrystalline ZrO{sub 2}. These oxygen vacancies are regarded as the essential stabilizing factor for the nanostructurally stabilized cubic zirconia.

  1. Grain growth in ZrFe thin films during in situ ion irradiation in a TEM

    E-Print Network [OSTI]

    Motta, Arthur T.

    Grain growth in Zr­Fe thin films during in situ ion irradiation in a TEM D. Kaoumi a,*, A.T. Motta Laboratory, Argonne, IL 060493, USA Available online 2 November 2005 Abstract In situ ion-beam irradiation was used to study irradiation induced grain growth in co-sputter-deposited Zr/xFe (0% 6 x 6 4

  2. Atomistic Studies of Cation Transport in Tetragonal ZrO2 During Zirconium Corrosion

    SciTech Connect (OSTI)

    Xian-Ming Bai; Yongfeng Zhang; Michael R. Tonks

    2013-10-01

    Zirconium alloys are the major fuel cladding materials in current reactors. The water-side corrosion is one of the major degradation mechanisms of these alloys. During corrosion the transport of oxidizing species in zirconium dioxide (ZrO2) determines the corrosion kinetics. Previously it has been argued that the outward diffusion of cation ions is important for forming protective oxides. In this work, the migration of Zr defects in tetragonal ZrO2 is studied with temperature accelerated dynamics and molecular dynamics simulations. The results show that Zr interstitials have anisotropic diffusion and migrate preferentially along the [001] or c direction in tetragonal ZrO2. The compressive stresses can increase the Zr interstitial migration barrier significantly. The migration barriers of some defect clusters can be much lower than those of point defects. The migration of Zr interstitials at some special grain boundaries is much slower than in a bulk oxide. The implications of these atomistic simulation results in the Zr corrosion are discussed.

  3. THREE-DIMENSIONAL ATOMIC STRUCTURE OF NiO ZrO2(CUBIC) INTERFACES

    E-Print Network [OSTI]

    Pennycook, Steve

    THREE-DIMENSIONAL ATOMIC STRUCTURE OF NiO± ZrO2(CUBIC) INTERFACES E. C. DICKEY{1 , V. P. DRAVID1-dimensional atomic structure of low-energy NiO±ZrO2(cubic) interfaces is determined through a combination of electron the structural and chemical aspects of the interface and associ- ated interfacial relaxation mechaubic) interface

  4. Report on Characterization of U-10 wt.% Zr Alloy

    SciTech Connect (OSTI)

    McKeown, J; Wall, M; Hsiung, L; Turchi, P

    2012-03-01

    This report summarizes the chemical and structural characterization results for a U-10 wt.% Zr alloy to be used in an ultra-high burn-up nuclear fuel concept. The as-cast alloy material was received from Texas A and M University. Characterization and an initial heat treatment of the alloy material were conducted at Lawrence Livermore National Laboratory. The as-received ingot was sectioned for X-ray analysis, metallography, SEM, TEM, and heat treatments, as shown in Figure 1.

  5. Active eutectoid decomposition in Zr-3 wt.% Fe

    SciTech Connect (OSTI)

    Kumar, L.; Ramanujan, R.V.; Tewari, R.; Mukhopadhyay, P.; Banerjee, S.

    1999-02-19

    In the work reported here, the microstructural features associated with the active eutectoid decomposition of a near eutectoid alloy (Zr-3 wt.%Fe) on {beta} quenching were examined. The effects of aging after {beta} quenching, and of furnace cooling from the {beta} phase field, on the microstructure of the alloy were also studied. The microstructural characterization was carried out using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM). The room temperature mechanical properties corresponding to some of the microstructures were evaluated by mechanical testing.

  6. Displacive radiation-induced structural contraction in nanocrystalline ZrN

    SciTech Connect (OSTI)

    Lu Fengyuan; Sun Hongtao; Lian Jie [Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytech Institute, Troy, New York 12180 (United States); Huang, Mengbing; Yaqoob, Faisal [Ion Beam Laboratory, University at Albany-SUNY, Albany, New York 12222 (United States); Lang, Maik; Ewing, Rodney C. [Departments of Earth and Environmental Sciences and Materials Sciences and Engineering, University of Michigan, Ann Arbor, Michigan 48109-1005 (United States); Namavar, Fereydoon [Department of Orthopaedic Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska 68198 (United States); Trautmann, Christina [GSI Helmholtz Center for Heavy Ion Research, 64291 Darmstadt (Germany); Technische Universitaet Darmstadt, 64289 Darmstadt (Germany)

    2012-07-23

    Nanocrystalline ZrN thin films with 5 nm grain size, prepared by ion beam assisted deposition, maintained their isometric structure upon intensive displacive and ionizing irradiations, indicating an extremely high stability similar to bulk ZrN. However, a unique structural contraction up to 1.42% in lattice parameter occurred only in nano-sized ZrN upon displacive irradiations. A significant nitrogen loss occurred with reduced N:Zr atomic ratio to 0.88, probably due to the production of displaced nitrogen atoms and fast diffusion along grain boundaries in nanocrystalline ZrN matrix. The accumulation of nitrogen vacancies and related strain relaxation may be responsible for the structural contraction.

  7. Effect of surface strain on oxygen adsorption on Zr (0001) surface

    SciTech Connect (OSTI)

    Wang, Xing [Univ. of Wisconsin-Madison, Madison, WI (United States). Dept. of Engineering Physics; Khafizov, Marat [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Szlufarska, Izabela [Univ. of Wisconsin-Madison, Madison, WI (United States). Dept. of Engineering Physics; Univ. of Wisconsin-Madison, Madison, WI (United States). Dept. of Materials Science and Engineering

    2014-02-01

    The effect of surface strain on oxygen adsorption on Zr (0 0 0 1) surface is investigated by density functional theory (DFT) calculations. It is demonstrated that both surface strain and interactions between oxygen adsorbates influence the adsorption process. Oxygen binding to zirconium becomes stronger as the strain changes from compressive to tensile. When oxygen coverage is low and the oxygen interactions are negligible, surface face-centered cubic sites are the most stable for O binding. At high coverage and under compression, octahedral sites between second and third Zr layers become most favorable because the interactions between adsorbates are weakened by positive charge screening. Calculations with both single-layer adsorption model and multiple-layer adsorption model demonstrate that compressive strain at the Zr/oxide interface will provide a thermodynamic driving force for oxygen to incorporate from the surface into the bulk of Zr, while binding oxygen to the Zr surface will be easier when tensile strain is applied.

  8. The Development of the Linac Coherent Light Source RF Gun

    SciTech Connect (OSTI)

    Dowell, David H.; Jongewaard, Erik; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling; /SLAC

    2008-09-24

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of the emittance compensation solenoid are discussed in Section 1.1.7. The novel feature of the LCLS solenoid is the embedded quadrupole correctors. The thermo-mechanical engineering of the LCLS gun is discussed in Section 1.1.8, and the cold and hot RF tests are described in Section 1.1.9. The results of this work are summarized and concluding remarks are given in Section 1.1.10.

  9. 332 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 51, NO. 1, JANUARY 2003 Monolithic Integration of RF MEMS Switches

    E-Print Network [OSTI]

    Cetiner, Bedri A.

    Integration of RF MEMS Switches With a Diversity Antenna on PCB Substrate B. A. Cetiner, Member, IEEE, J. Y integration of RF mi- croelectromechanical system (MEMS) switches with three-dimen- sional antenna elements with RF MEMS switches is designed and demonstrated. Index Terms--RF microelectromechanical system (MEMS

  10. GEO 600 and the GEO-HF upgrade program: successes and challenges

    E-Print Network [OSTI]

    Dooley, K L; Adams, T; Affeldt, C; Bisht, A; Bogan, C; Degallaix, J; Gräf, C; Hild, S; Hough, J; Khalaidovski, A; Lastzka, N; Lough, J; Lück, H; Macleod, D; Nuttall, L; Prijatelj, M; Schnabel, R; Schreiber, E; Slutsky, J; Sorazu, B; Strain, K A; Vahlbruch, H; Was, M; Willke, B; Wittel, H; Danzmann, K; Grote, H

    2015-01-01

    The German-British laser-interferometric gravitational wave detector GEO 600 is in its 14th year of operation since its first lock in 2001. After GEO 600 participated in science runs with other first-generation detectors, a program known as GEO-HF began in 2009. The goal was to improve the detector sensitivity at high frequencies with technologically advanced yet minimally invasive upgrades. Simultaneously, the detector would record science quality data in between commissioning activities. As of early 2014, all of the planned upgrades have been carried out and sensitivity improvements of up to a factor of four at the high-frequency end of the observation band have been achieved. Besides science data collection, an experimental program is ongoing with the goal to further improve the sensitivity and evaluate future detector technologies. We summarize the results of the GEO-HF program to date and discuss its successes and challenges.

  11. Shape memory response and microstructural evolution of a severe plastically deformed high temperature shape memory alloy (NiTiHf

    E-Print Network [OSTI]

    Simon, Anish Abraham

    2006-04-12

    NiTiHf alloys have attracted considerable attention as potential high temperature Shape Memory Alloy (SMA) but the instability in transformation temperatures and significant irrecoverable strain during thermal cycling under constant stress remains a...

  12. HF Radar Performance in a Low-Energy Environment: CODAR SeaSonde Experience on the West Florida Shelf*

    E-Print Network [OSTI]

    both tidal and subtidal frequency bands. By examining the HF radar radial velocities at low wave energy have evolved along with coastal ocean circulation-observing technologies. Early inferences on surface

  13. Electronic properties of InP (001)/HfO{sub 2} (001) interface: Band offsets and oxygen dependence

    SciTech Connect (OSTI)

    KC, Santosh; Dong, Hong; Longo, Roberto C.; Xiong, Ka [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States); Wang, Weichao [Department of Electronics and Microelectronics and Tianjin Key Laboratory of Photo-Electronic Thin Film Device and Technology, Nankai University, Tianjin 300071 (China); Wallace, Robert M.; Cho, Kyeongjae, E-mail: kjcho@utdallas.edu [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States); Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2014-01-14

    Using ab-initio methods, atomic structures and electronic properties of InP (001)/HfO{sub 2} (001) interface are studied within the framework of density functional theory. We examine the InP/HfO{sub 2} model interface electronic structures under varying oxidation conditions. The effects of indium and phosphorous concentrations on interfacial bonding, defect states, band offsets, and the thermodynamic stability at the interface are also investigated. The origin of interfacial gap states in InP (001)/HfO{sub 2} (001) interface are proposed, mainly from the P-rich oxides, which is validated by our experimental work. This highlights the importance of surface passivation prior to high-? deposition based on the in situ spectroscopic results of atomic layer deposition of HfO{sub 2} on InP.

  14. Coexistence of different charge states in Ta-doped monoclinic HfO2: Theoretical and experimental approaches

    E-Print Network [OSTI]

    Svane, Axel Torstein

    and with the addition of small amounts of impurities, it has applications ranging from solid oxide fuel cell attention due to its potential technological applications. HfO2 is a wide-band- gap semiconductor

  15. Assessment of Alternative RF Linac Structures for APT

    SciTech Connect (OSTI)

    1997-03-26

    The APT program has been examining both normal and superconducting variants of the APT linac for the past two years. A decision on which of the two will be the selected technology will depend upon several considerations including the results of ongoing feasibility experiments, the performance and overall attractiveness of each of the design concepts, and an assessment of the system-level features of both alternatives. The primary objective of the Assessment of Alternative RF Linac Structures for APT study reported herein was to assess and compare, at the system-level, the performance, capital and life cycle costs, reliability/availability/maintainability (RAM) and manufacturing schedules of APT RF linear accelerators based upon both superconducting and normal conducting technologies. A secondary objective was to perform trade studies to explore opportunities for system optimization, technology substitution and alternative growth pathways and to identify sensitivities to design uncertainties.

  16. STATUS OF THE SPALLATION NEUTRON SOURCE SUPERCONDUCTING RF FACILITIES

    SciTech Connect (OSTI)

    Stout, Daniel S [ORNL] [ORNL; Assadi, Saeed [ORNL] [ORNL; Campisi, Isidoro E [ORNL] [ORNL; Casagrande, Fabio [ORNL] [ORNL; Crofford, Mark T [ORNL] [ORNL; DeVan, Bill [ORNL] [ORNL; Hardek, Thomas W [ORNL] [ORNL; Henderson, Stuart D [ORNL] [ORNL; Howell, Matthew P [ORNL] [ORNL; Kang, Yoon W [ORNL] [ORNL; Geng, Xiaosong [ORNL] [ORNL; Stone Jr, William C [ORNL] [ORNL; Strong, William Herb [ORNL] [ORNL; Williams, Derrick C [ORNL] [ORNL; Wright, Paul Alan [ORNL] [ORNL

    2007-01-01

    The Spallation Neutron Source (SNS) project was completed with only limited superconducting RF (SRF) facilities installed as part of the project. A concerted effort has been initiated to install the infrastructure and equipment necessary to maintain and repair the superconducting Linac, and to support power upgrade research and development (R&D). Installation of a Class10/100/10,000 cleanroom and outfitting of the test cave with RF, vacuum, controls, personnel protection and cryogenics systems is underway. A horizontal cryostat, which can house a helium vessel/cavity and fundamental power coupler for full power, pulsed testing, is being procured. Equipment for cryomodule assembly and disassembly is being procured. This effort, while derived from the experience of the SRF community, will provide a unique high power test capability as well as long term maintenance capabilities. This paper presents the current status and the future plans for the SNS SRF facilities.

  17. Linear Gain for the Microbunching Instability in an RF Compressor

    SciTech Connect (OSTI)

    Venturini, M.; Migliorati, M.; Ronsivalle, C.; Vaccarezza, C.

    2009-05-01

    Velocity (or rf) compression has been suggested as a technique for bunch compression complementary to the more established technique involving magnetic chicanes and represents an important research item being investigated at the SPARC test facility. One of the aspects of this technique still not sufficiently understood is its possible impact on the microbunching instability. The purpose of this report is to present the analytical framework for investigating this instability in rf compressors. We use methods similar to those successfully applied to magnetic compressors and derive some integral equations yielding the gain for the instability in linear approximation. The focus here is on the derivation of the relevant equations. Although examples of solutions to these equations are provided we defer a more comprehensive discussion of their implication to a future report. The present study is part of a larger effort for a more comprehensive investigation that eventually will include macroparticle simulations and experiments.

  18. Free electron laser using Rf coupled accelerating and decelerating structures

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

    1984-01-01

    A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is generated from the energy depleted electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy generated from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.

  19. Short-Period RF Undulator for a SASE Nanometer source

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2001-12-21

    Analysis is described towards development of a RF undulator with a period < 1 cm, an undulator parameter K of the order of unity, and a gap greater than 2.25 mm. The application for the undulator is for a SASE source to produce 1 nm wavelength radiation using a low energy electron beam in the range 1-2 GeV. Particle orbit calculations in a conventional standing-wave resonator configuration show that the presence of a co-propagating component of RF field can cause deleterious motion for the undulating electrons that can seriously degrade their radiation spectrum. To obviate this problem, resonator designs were devised in which only the counter-propagating field components interact with the particles. Two resonator configurations with the same undulator parameter K = 0.4 have been devised and are described in this report.

  20. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    Shu, G; Pei, S; Xiao, O

    2015-01-01

    An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the output peak power is about 500 MW at the phase reversal time. In order to deal with the RF breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, amplitude modulation and phase modulation with flat-top output were taken into account. The RF modulation studies on an S-band SLED are presented in this paper. Furthermore, a method is developed by using the CST Microwave Studio transient solver to simulate the time response of the pulse compressor, which can be a verification of the modulate theory. In addition, the experimental setup was constructed and the flat-top output is obtained in the low power tests.

  1. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    G. Shu; F. Zhao; S. Pei; O. Xiao

    2015-05-28

    An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the output peak power is about 500 MW at the phase reversal time. In order to deal with the RF breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, amplitude modulation and phase modulation with flat-top output were taken into account. The RF modulation studies on an S-band SLED are presented in this paper. Furthermore, a method is developed by using the CST Microwave Studio transient solver to simulate the time response of the pulse compressor, which can be a verification of the modulate theory. In addition, the experimental setup was constructed and the flat-top output is obtained in the low power tests.

  2. Characterization on RF magnetron sputtered niobium pentoxide thin films

    SciTech Connect (OSTI)

    Usha, N. [Department of Physics, Alagappa University, Karaikudi - 630 004 (India); Sivakumar, R., E-mail: krsivakumar1979@yahoo.com [Directorate of Distance Education, Alagappa University, Karaikudi - 630 004 (India); Sanjeeviraja, C. [Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi - 630 004 (India)

    2014-10-15

    Niobium pentoxide (Nb{sub 2}O{sub 5}) thin films with amorphous nature were deposited on microscopic glass substrates at 100°C by rf magnetron sputtering technique. The effect of rf power on the structural, morphological, optical, and vibrational properties of Nb{sub 2}O{sub 5} films have been investigated. Optical study shows the maximum average transmittance of about 87% and the optical energy band gap (indirect allowed) changes between 3.70 eV and 3.47 eV. AFM result indicates the smooth surface nature of the samples. Photoluminescence measurement showed the better optical quality of the deposited films. Raman spectra show the LO-TO splitting of Nb-O stretching of Nb{sub 2}O{sub 5} films.

  3. Multipacting optimization of a 750 MHz rf dipole

    SciTech Connect (OSTI)

    Delayen, Jean R.; Castillo, Alejandro

    2014-12-01

    Crab crossing schemes have been proposed to re-instate luminosity degradation due to crossing angles at the interaction points in next generation colliders to avoid the use of sharp bending magnets and their resulting large synchrotron radiation generation, highly undessirable in the detector region. The rf dipole has been considered for a different set of applications in several machines, both rings and linear colliders. We present in this paper a study of the effects on the multipacting levels and location depending on geometrical variations on the design for a crabbing/deflecting application in a high current (3/0.5 A), high repetition (750 MHz) electron/proton collider, as a matter to provide a comparison point for similar applications of rf dipoles.

  4. Mode specificity in the HF + OH ? F + H{sub 2}O reaction

    SciTech Connect (OSTI)

    Song, Hongwei; Li, Jun; Guo, Hua

    2014-10-28

    Full-dimensional quantum dynamics and quasi-classical trajectory calculations are reported for the title reaction on a recently constructed ab initio based global potential energy surface. Strong mode specificity was found, consistent with the prediction of the sudden vector projection model. Specifically, the HF vibration strongly promotes the reaction while the OH vibration has little effect. Rotational excitations of both reactants slightly enhance the reaction.

  5. Design of Superconducting Parallel Bar Deflecting and Crabbing rf Structures

    SciTech Connect (OSTI)

    Jean Delayen, Haipeng Wang

    2009-05-01

    A new concept for a deflecting and crabbing rf structure based on half-wave resonant lines was introduced recently*. It offers significant advantages to existing designs and, because of it compactness, allows low frequency operation. This concept has been further refined and optimized for superconducting implementation. Results of this optimization and application to a 400 MHz crabbing cavity and a 499 MHz deflecting cavity are presented.

  6. High gradient rf gun studies of CsBr photocathodes

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

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-03

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 2×10?? torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  7. Holographic Superconductors with the General $RF^2$-type Couplings

    E-Print Network [OSTI]

    Özcan Sert

    2015-07-25

    We explore the effects of the general non-minimally coupled $RF^2$-type couplings on the holographic superconductors numerically in the Schwarzschild-AdS background. We calculate the conductivity of the model and find that the increase of parameters $a_1$ and $\\beta$ lead to the lower gap frequency. Thus, we can obtain the weakly coupled BCS value $ \\omega_g/T_c \\approx 3.5$ for some coupling parameters of this model.

  8. Modeling rf breakdown arcs II: plasma / materials interactions

    E-Print Network [OSTI]

    Insepov, Zeke; Proslier, Thomas; Mahalingam, Sudhakar; Veitzer, S

    2010-01-01

    Continuing the description of rf vacuum arcs from an earlier paper, we describe some aspects of the interaction of vacuum arcs that involve the surface. This paper describes aspects of plasma materials interactions that affect the arc and models measurement of the surface field using the Tonks-Frenkel and the spinodal electrohydrodynamic instabilities, a realistic model for the generation and evaluation of high field enhancements, unipolar arcs, creep and other effects.

  9. Nano-electromechanical oscillators (NEMOs) for RF technologies.

    SciTech Connect (OSTI)

    Wendt, Joel Robert; Czaplewski, David A.; Gibson, John Murray (Argonne National Laboratory, Argonne, IL); Webster, James R.; Carton, Andrew James; Keeler, Bianca Elizabeth Nelson; Carr, Dustin Wade; Friedmann, Thomas Aquinas; Tallant, David Robert; Boyce, Brad Lee; Sullivan, John Patrick; Dyck, Christopher William; Chen, Xidong (Cedarville University, Cedarville, OH)

    2004-12-01

    Nano-electromechanical oscillators (NEMOs), capacitively-coupled radio frequency (RF) MEMS switches incorporating dissipative dielectrics, new processing technologies for tetrahedral amorphous carbon (ta-C) films, and scientific understanding of dissipation mechanisms in small mechanical structures were developed in this project. NEMOs are defined as mechanical oscillators with critical dimensions of 50 nm or less and resonance frequencies approaching 1 GHz. Target applications for these devices include simple, inexpensive clocks in electrical circuits, passive RF electrical filters, or platforms for sensor arrays. Ta-C NEMO arrays were used to demonstrate a novel optomechanical structure that shows remarkable sensitivity to small displacements (better than 160 fm/Hz {sup 1/2}) and suitability as an extremely sensitive accelerometer. The RF MEMS capacitively-coupled switches used ta-C as a dissipative dielectric. The devices showed a unipolar switching response to a unipolar stimulus, indicating the absence of significant dielectric charging, which has historically been the major reliability issue with these switches. This technology is promising for the development of reliable, low-power RF switches. An excimer laser annealing process was developed that permits full in-plane stress relaxation in ta-C films in air under ambient conditions, permitting the application of stress-reduced ta-C films in areas where low thermal budget is required, e.g. MEMS integration with pre-existing CMOS electronics. Studies of mechanical dissipation in micro- and nano-scale ta-C mechanical oscillators at room temperature revealed that mechanical losses are limited by dissipation associated with mechanical relaxation in a broad spectrum of defects with activation energies for mechanical relaxation ranging from 0.35 eV to over 0.55 eV. This work has established a foundation for the creation of devices based on nanomechanical structures, and outstanding critical research areas that need to be addressed for the successful application of these technologies have been identified.

  10. Holographic Superconductors with the General $RF^2$-type Couplings

    E-Print Network [OSTI]

    Sert, Özcan

    2015-01-01

    We explore the effects of the general non-minimally coupled $RF^2$-type couplings on the holographic superconductors numerically in the Schwarzschild-AdS background. We calculate the conductivity of the model and find that the increase of parameters $a_1$ and $\\beta$ lead to the lower gap frequency. Thus, we can obtain the weakly coupled BCS value $ \\omega_g/T_c \\approx 3.5$ for some coupling parameters of this model.

  11. Local nonlinear rf forces in inhomogeneous magnetized plasmas

    SciTech Connect (OSTI)

    Chen, Jiale, E-mail: chen@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Gao, Zhe [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

    2014-06-15

    The local nonlinear forces induced by radio frequency (rf) waves are derived in inhomogeneous magnetized plasmas, where the inhomogeneity exists in the rf fields, in the static magnetic field as well as in the equilibrium density and temperature. The local parallel force is completely resonant, but a novel component dependent on those inhomogeneities is obtained as the result of the inhomogeneous transport of parallel resonant-absorbed momentum by the nonlinear perpendicular drift flux. In the local poloidal force, the component induced by the inhomogeneity of rf power absorption is also confirmed and it can be recognized as the residual effect from the incomplete cancellation between the rate of the diamagnetic poloidal momentum gain and the Lorentz force due to the radial diffusion-like flux. The compact expression for radial force is also obtained for the first time, whose nonresonant component is expressed as the sum of the ponderomotive force on particles and the gradients of the nonresonant perpendicular pressure and of the nonresonant momentum flux due to the finite temperature effect. Numerical calculations in a 1-D slab model show that the resonant component dependent on the inhomogeneities may be significant when the ion absorption dominates the resonant wave-particle interaction. A quantitative estimation shows that the novel component in the parallel force is important to understand the experiments of the ion-cyclotron-frequency mode-conversion flow drive.

  12. RF Input Power Couplers for High Current SRF Applications

    SciTech Connect (OSTI)

    Khan, V. F.; Anders, W.; Burrill, Andrew; Knobloch, Jens; Kugeler, Oliver; Neumann, Axel; Wang, Haipeng

    2014-12-01

    High current SRF technology is being explored in present day accelerator science. The bERLinPro project is presently being built at HZB to address the challenges involved in high current SRF machines with the goal of generating and accelerating a 100 mA electron beam to 50 MeV in continuous wave (cw) mode at 1.3 GHz. One of the main challenges in this project is that of handling the high input RF power required for the photo-injector as well as booster cavities where there is no energy recovery process. A high power co-axial input power coupler is being developed to be used for the photo-injector and booster cavities at the nominal beam current. The coupler is based on the KEK–cERL design and has been modified to minimise the penetration of the coupler tip in the beam pipe without compromising on beam-power coupling (Qext ~105). Herein we report on the RF design of the high power (115 kW per coupler, dual couplers per cavity) bERLinPro (BP) coupler along with initial results on thermal calculations. We summarise the RF conditioning of the TTF-III couplers (modified for cw operation) performed in the past at BESSY/HZB. A similar conditioning is envisaged in the near future for the low current SRF photo-injector and the bERLinPro main linac cryomodule.

  13. A RF Lateral BJT on SOI for realization of RF SOI-BiCMOS I-Shan Michael Sun, Wai Tung Ng*, Hidenori Mochizuki, Koji Kanekiyo, Takaaki Kobayashi,

    E-Print Network [OSTI]

    Ng, Wai Tung

    A RF Lateral BJT on SOI for realization of RF SOI-BiCMOS Technology I-Shan Michael Sun, Wai Tung Ng between 190-300 GHz·V. The fmax of the optimal device reaches 46 GHz at collector current density of only vertical BJT requires thick- film SOI (>1µm) for the collector region, but is incompatible with thin

  14. Structures and magnetic properties of Co-Zr-B magnets studied by first-principles calculations

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

    Zhao, Xin; Ke, Liqin; Nguyen, Manh Cuong; Wang, Cai-Zhuang; Ho, Kai-Ming

    2015-06-23

    The structures and magnetic properties of Co-Zr-B alloys near the composition of Co5Zr with B at. % ?6% were studied using adaptive genetic algorithm and first-principles calculations. The energy and magnetic moment contour maps as a function of chemical composition were constructed for the Co-Zr-B magnet alloys through extensive structure searches and calculations. We found that Co-Zr-B system exhibits the same structure motif as the “Co11Zr2”polymorphs, and such motif plays a key role in achieving strong magnetic anisotropy. Boronatoms were found to be able to substitute cobalt atoms or occupy the “interruption” sites. First-principles calculations showed that the magnetocrystalline anisotropymore »energies of the boron-doped alloys are close to that of the high-temperature rhombohedral Co5Zr phase and larger than that of the low-temperature Co5.25Zr phase. Our calculations provide useful guidelines for further experimental optimization of the magnetic performances of these alloys.« less

  15. Isothermal oxidation behavior of ternary Zr-Nb-Y alloys at high temperature

    SciTech Connect (OSTI)

    Prajitno, Djoko Hadi, E-mail: djokohp@batan.go.id [Research Center for Nuclear Materials and Radiometry, Jl. Tamansari 71, Bandung 40132 (Indonesia); Soepriyanto, Syoni; Basuki, Eddy Agus [Metallurgy Engineering, Institute Technology Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Wiryolukito, Slameto [Materials Engineering, Institute Technology Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    The effect of yttrium content on isothermal oxidation behavior of Zr-2,5%Nb-0,5%Y, Zr-2,5%Nb-1%Y Zr-2,5%Nb-1,5%Y alloy at high temperature has been studied. High temperature oxidation carried out at tube furnace in air at 600,700 and 800°C for 1 hour. Optical microscope is used for microstructure characterization of the alloy. Oxidized and un oxidized specimen was characterized by x-ray diffraction. In this study, kinetic oxidation of Zr-2,5%Nb with different Y content at high temperature has also been studied. Characterization by optical microscope showed that microstructure of Zr-Nb-Y alloys relatively unchanged and showed equiaxed microstructure. X-ray diffraction of the alloys depicted that the oxide scale formed during oxidation of zirconium alloys is monoclinic ZrO2 while unoxidised alloy showed two phase ? and ? phase. SEM-EDS examination shows that depletion of Zr composition took place under the oxide layer. Kinetic rate of oxidation of zirconium alloy showed that increasing oxidation temperature will increase oxidation rate but increasing yttrium content in the alloys will decrease oxidation rate.

  16. Ab initio density functional theory study of uranium solubility in Gd2Zr2O7 pyrochlore

    E-Print Network [OSTI]

    Chen, Qing-yun; Meng, Chuan-min; Liao, Chang-zhong; Wang, Lie-lin; Xie, Hua; Lv, Hui-yi; Wu, Tao; Ji, Shi-yin; Huang, Yu-zhu

    2015-01-01

    In this study, an ab initio calculation is performed to investigate the uranium solubility in different sites of Gd2Zr2O7 pyrochlore. The Gd2Zr2O7 maintains its pyrochlore structure at low uranium dopant levels, and the lattice constants of Gd2(Zr2-yUy)O7 and (Gd2-yUy)Zr2O7 are generally expressed as being linearly related to the uranium content y. Uranium is found to be a preferable substitute for the B-site gadolinium atoms in cation-disordered Gd2Zr2O7 (where gadolinium and zirconium atoms are swapped) over the A-site gadolinium atoms in ordered Gd2Zr2O7 due to the lower total energy of (Gd2-yZry)(Zr2-yUy)O7. The theoretical findings present a reasonable explanation of recent experiment results.

  17. Structural relaxation and nanoindentation response in Zr-Cu-Ti amorphous thin films

    SciTech Connect (OSTI)

    Chou, H. S.; Huang, J. C.; Chang, L. W. [Department of Materials and Optoelectronic Science, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Nieh, T. G. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2008-11-10

    Ternary Zr-Cu-Ti system, especial with a high Ti content, is normally difficult to be fully vitrified. In this paper, we demonstrate that cosputtering can produce amorphous Zr-Cu-Ti thin films with an excessive Ti content even as high as 19%. Sub-T{sub g} annealing of the film induces the formation of medium-range-ordered clusters and to raise the nanohardness by 35% to 6.6 GPa. The promising mechanical properties of the sub-T{sub g} annealed Zr{sub 52}Cu{sub 29}Ti{sub 19} films offer great potential for microelectromechanical system applications.

  18. Quantitative phase analysis of Mg:ZrO{sub 2} nanoparticles by Rietveld refinement method

    SciTech Connect (OSTI)

    Balaji, V. Senthilkumaran, S. Thangadurai, P.

    2014-04-24

    To quantify the structural phases of nanocrystalline ZrO{sub 2} doped with Mg ions of varying concentrations (3, 5, 10, 15 and 20%) and annealed at different temperatures. Magnesia doped zirconia was prepared by chemical co-precipitation method and annealed up to 1000°C. The monoclinic and tetragonal phases present in Mg:ZrO{sub 2} were quantified using Rietveld refinement analysis of the X-ray diffraction data and compared with the Direct method based on peak intensity calculations. Tetragonal phase was dominant in the 600°C annealed Mg:ZrO{sub 2} for all Mg concentrations.

  19. Isoscalar Breathing Mode State in Zr-90 and Sn-116 

    E-Print Network [OSTI]

    Rozsa, C. M.; Youngblood, David H.; Bronson, J. D.; Lui, YW; Garg, U.

    1980-01-01

    the AEr gate alone was able to remove essentially all unwanted events, the E' and TOF gates were maintained for additional discrim- ination. Two sets of these gates could be set to collect data in different exit channels. Three 2048 channel position... parameters. Nucleus (MeV) (MeV) W (Me V) t'p (fm) Qp (fm) &c Data angle range ~zr ?6Sn 96 129 45.7 60.8 27.7 40.9 1.50 1.40 0.70 0.73 1.30 1.35 (9'-57') (12'-50') TABLE III. Param. eters of the GMR and GQR. The er- rors...

  20. Pygmy dipole resonance and dipole polarizability in {sup 90}Zr

    SciTech Connect (OSTI)

    Iwamoto, C.; Tamii, A.; Shima, T.; Hashimoto, T.; Suzuki, T.; Fujita, H.; Hatanaka, K. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Utsunomiya, H.; Akimune, H.; Yamagata, T.; Okamoto, A.; Kondo, T. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan); Nakada, H. [Department of Physics, Graduate School of Science, Chiba University, Yayoi-cho 1-33, Inage, Chiba 263-8522 (Japan); Kawabata, T. [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Fujita, Y. [Department of Physics, Osaka University, Toyonaka, Osaka, 560-0043 (Japan); Matsubara, H. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Shimbara, Y.; Nagashima, M. [Department of Physics, Niigata University, Niigata 950-21-2 (Japan); Sakuda, M.; Mori, T. [Department of Physics, Okayama University, Okayama 900-0082 (Japan); and others

    2014-05-02

    Electric dipole (E1) reduced transition probability B(E1) of {sup 90}Zr was obtained by the inelastic proton scattering near 0 degrees using a 295 MeV proton beam and multipole decomposition analysis of the angular distribution by the distorted-wave Born approximation with the Hartree-Fock plus random-phase approximation model and inclusion of El Coulomb excitation, and the E1 strength of the pygmy dipole resonance was found in the vicinity of the neutron threshold in the low-energy tail of the giant dipole resonance. Using the data, we plan to determine the precise dipole polarizability ?{sub D} which is defined as an inversely energy-weighted sum value of the elecrric dipole strength. The dipole polarizability is expected to constrain the symmetry energy term of the neutron matter equation of state. Thus systematical measurement of the dipole polarizability is important.

  1. Ultrananocrystalline diamond films with optimized dielectric properties for advanced RF MEMS capacitive switches

    DOE Patents [OSTI]

    Sumant, Anirudha V.; Auciello, Orlando H.; Mancini, Derrick C.

    2013-01-15

    An efficient deposition process is provided for fabricating reliable RF MEMS capacitive switches with multilayer ultrananocrystalline (UNCD) films for more rapid recovery, charging and discharging that is effective for more than a billion cycles of operation. Significantly, the deposition process is compatible for integration with CMOS electronics and thereby can provide monolithically integrated RF MEMS capacitive switches for use with CMOS electronic devices, such as for insertion into phase array antennas for radars and other RF communication systems.

  2. Performance of the high power rf system for the NIST--Los Alamos racetrack microtron

    SciTech Connect (OSTI)

    Cutler, R.I.; Young, L.

    1988-01-01

    The high power RF system of the NIST-LANL RTM has been tested at nominal full power levels and has accelerated electron beams successfully. RF stability and calibration measurements have been made using the accelerated electron beam. These measurements have been used to calculate the effective shunt impedance of the side- coupled accelerator structure. RF stability measurements were also performed using power meters and phase detectors. 7 refs., 4 figs.

  3. Performance enhancement of GaN metal–semiconductor–metal ultraviolet photodetectors by insertion of ultrathin interfacial HfO{sub 2} layer

    SciTech Connect (OSTI)

    Kumar, Manoj E-mail: aokyay@ee.bilkent.edu.tr; Tekcan, Burak; Okyay, Ali Kemal E-mail: aokyay@ee.bilkent.edu.tr

    2015-03-15

    The authors demonstrate improved device performance of GaN metal–semiconductor–metal ultraviolet (UV) photodetectors (PDs) by ultrathin HfO{sub 2} (UT-HfO{sub 2}) layer on GaN. The UT-HfO{sub 2} interfacial layer is grown by atomic layer deposition. The dark current of the PDs with UT-HfO{sub 2} is significantly reduced by more than two orders of magnitude compared to those without HfO{sub 2} insertion. The photoresponsivity at 360?nm is as high as 1.42 A/W biased at 5 V. An excellent improvement in the performance of the devices is ascribed to allowed electron injection through UT-HfO{sub 2} on GaN interface under UV illumination, resulting in the photocurrent gain with fast response time.

  4. Stress-tolerant and temperature-stable RF MEMS capacitive switches and tunable filters

    E-Print Network [OSTI]

    Reines, Isak C.

    2010-01-01

    4.2 UCSD Switch Design . . . . . . . . . . . . . . .5.2 Switch Design . . . . . . . . . . . . . . .2.2 Switch Design in the Raytheon RF MEMS Process . . . . .

  5. Dependence of the microwave surface resistance of superconducting niobium on the magnitude of the rf field

    SciTech Connect (OSTI)

    Romanenko, A.; Grassellino, A. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)] [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

    2013-06-24

    Utilizing difference in temperature dependencies we decoupled Bardeen-Cooper-Schrieffer (BCS) and residual components of the microwave surface resistance of superconducting niobium at all rf fields up to B{sub rf}{approx}115 mT. We reveal that the residual resistance decreases with field at B{sub rf} Less-Than-Or-Equivalent-To 40 mT and strongly increases in chemically treated niobium at B{sub rf}>80 mT. We find that BCS surface resistance is weakly dependent on field in the clean limit, whereas a strong and peculiar field dependence emerges after 120 Degree-Sign C vacuum baking.

  6. High performance RF MEMS metal-contact switches and switching networks

    E-Print Network [OSTI]

    Patel, Chirag D.; Patel, Chirag D.

    2012-01-01

    MEMS switches for RF applications,” MicroelectromechanicalMEMS switch with a corrugated diaphragm,” MicroelectromechanicalMEMS switch technology for high frequency applications,” in Microelectromechanical

  7. RF physics of ICWC discharge at high cyclotron harmonics

    SciTech Connect (OSTI)

    Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M. [Association Euratom-Belgian State, LPP-ERM-KMS, 1000 Brussels (Belgium); Bobkov, V.; Rohde, V.; Schneider, P. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching (Germany); Douai, D.; Kogut, D. [Association Euratom-CEA, CEA, IRFM, 13108 St Paul lez Durance (France); Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G. [Association Euratom-IEK-4, Forschungszentrum Jülich, 52425 Jülich (Germany); Moiseenko, V. [Institute of Plasma Physics NSC KIPT, 61108 Kharkiv (Ukraine); Noterdaeme, J.-M. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching, Germany and Ghent University, 9000 Ghent (Belgium); Collaboration: TEXTOR Team; ASDEX Upgrade Team

    2014-02-12

    Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,?=?{sub H+}, and with its high cyclotron harmonics (HCH), ?=10?{sub cH+}? HCH scenario: very high antenna coupling to low density RF plasmas (P{sub pl}?0.9P{sub RF-G}) and low energy Maxwellian distribution of CX hydrogen atoms with temperature T{sub H}?350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E{sub ?H} ?1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of B{sub T}-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low T{sub e} plasmas is studied at fundamental ICR and its high harmonics.

  8. Low beryllium content Zr-based bulk metallic glass composite with plasticity and work hardenability

    SciTech Connect (OSTI)

    Zheng, Q., E-mail: qiangzheng616@hotmail.com, E-mail: dujuan@nimte.ac.cn [School of Materials Science and Engineering, Ningbo University of Technology, Ningbo, 315016, China and Ningbo Branch of China Academy of Ordnance Science, Ningbo, 315103 (China); Du, J., E-mail: qiangzheng616@hotmail.com, E-mail: dujuan@nimte.ac.cn [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, NIMTE, CAS, Ningbo 315201 (China)

    2014-01-28

    A modified Zr-based bulk metallic glass matrix composite Zr{sub 47.67}Cu{sub 40}Ti{sub 3.66}Ni{sub 2.66}Be{sub 6} has been produced by increasing the contents of elements of Zr and Cu with higher Poisson ratio and reducing the contents of Ti, Ni, and Be elements with lower Poisson ratio based on famous metallic glass former Vitreloy 1. A compressive yielding strength of 1804?MPa, fracture strength of 1938?MPa and 3.5% plastic strain was obtained for obtained metallic glass composite. Also, work-hardening behavior was observed during compressive experiment which was ascribed to the interaction of the in situ precipitated CuZr phase and shear bands.

  9. Analysis of the electronic structure of ZrO{sub 2} by Compton spectroscopy

    SciTech Connect (OSTI)

    Mahammad, F. M.; Mahammed, S. F. [University of Tikrit 42, Department of Physics (Iraq)] [University of Tikrit 42, Department of Physics (Iraq); Kumar, R.; Vijay, Y. K.; Sharma, B. K. [University of Rajasthan, Department of Physics (India)] [University of Rajasthan, Department of Physics (India); Sharma, G., E-mail: gsphysics@gmail.com [University of Kota, Department of Pure and Applied Physics (India)

    2013-07-15

    The electronic structure of ZrO{sub 2} is studied using the Compton scattering technique. The first-ever Compton profile measurement on polycrystalline ZrO{sub 2} was obtained using 59.54 keV gamma-rays emanating from the {sup 241}Am radioisotope. To explain the experimental data, we compute theoretical Compton profile values using the method of linear combination of atomic orbitals in the framework of density functional theory. The correlation scheme proposed by Perdew-Burke-Ernzerhof and the exchange scheme of Becke are considered. The ionic-model-based calculations for a number of configurations, i.e., Zr{sup +x}(O{sup -x/2}){sub 2} (0 {<=} x {<=} 2), are also performed to estimate the charge transfer on compound formation, and the study supports transfer of 1.5 electrons from Zr to O atoms.

  10. Oxidation induced amorphous stabilization of the subsurface region in Zr-Cu metallic glass

    SciTech Connect (OSTI)

    Lim, K. R. [Light Metal Division, Korea Institute of Materials Science, 797 Changwondaero, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Park, J. M. [Materials Research Center, Samsung Advanced Institute of Technology (SAIT) San 14-1, Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-712 (Korea, Republic of); Park, S. H.; Na, M. Y.; Kim, K. C.; Kim, D. H., E-mail: dohkim@yonsei.ac.kr [Department of Materials Science and Engineering, Center for Non-crystalline Materials, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Kim, W. T. [Department of Optical Engineering, Cheongju University, 36 Naedock-dong, Cheongju 360-764 (Korea, Republic of)

    2014-01-20

    In the present study, we demonstrate that selective surface oxidation of Zr{sub 70}Cu{sub 30} metallic glass can stabilize the amorphous structure in the subsurface region of the matrix. The oxidation proceeds by selective oxidation of Zr, forming monoclinic ZrO{sub 2} layer on the surface, and the subsurface layer becomes Cu-enriched due to back diffusion of Cu atoms from the oxide layer. Interestingly, in this system, the composition change in the subsurface region leads to enhancement of glass stability, forming of a double layered surface structure consisted of inner amorphous layer and outer monoclinic ZrO{sub 2} layer even when the remaining matrix is completely crystallized.

  11. The Structural Role of Zr within Alkali Borosilicate Glasses for Nuclear Waste Immobilisation

    SciTech Connect (OSTI)

    A Connelly; N Hyatt; K Travis; R Hand; E Maddrell; R Short

    2011-12-31

    Zirconium is a key constituent element of High Level nuclear Waste (HLW) glasses, occurring both as a fission product and a fuel cladding component. As part of a wider research program aimed at optimizing the solubility of zirconium in HLW glasses, we have investigated the structural chemistry of zirconium in such materials using X-ray Absorption Spectroscopy (XAS). Zirconium K-edge XAS data were acquired from several inactive simulant and simplified waste glass compositions, including a specimen of blended Magnox/UO{sub 2} fuel waste glass. These data demonstrate that zirconium is immobilized as (octahedral) six-fold coordinate ZrO{sub 6} species in these glasses, with a Zr-O contact distance of 2.09 {angstrom}. The next nearest neighbors of the Zr species are Si at 3.42 {angstrom} and possibly Na at 3.44 {angstrom}, no next nearest neighbor Zr could be resolved.

  12. Glass Forming Ability and Relaxation Behavior of Zr Based Metallic Glasses 

    E-Print Network [OSTI]

    Kamath, Aravind Miyar

    2012-07-16

    was studied by using thermal techniques to determine important GFA indicators for Zr-based bulk metallic glasses (BMG). The effect of alloying elements, annealing temperature and annealing time on the thermal and structural relaxation of the BMGs was studied...

  13. Model for Simulation of Hydride Precipitation in Zr-Based Used...

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

    a meso-scale, microstructural evolution model for simulation of zirconium hydride precipitation in the cladding of used fuels during long-term dry-storage. While the Zr-based...

  14. Fabrication Processes for the PEP II RF Cavities

    SciTech Connect (OSTI)

    Franks, R.Mark; /LLNL, Livermore; Rimmer, Robert A.; /LBL, Berkeley; Schwarz, Heinz; /SLAC

    2011-09-01

    This paper presents the major steps used in the fabrication of the 26 RF Cavities required for the PEP-II B-factory. Several unique applications of conventional processes have been developed and successfully implemented: electron beam welding (EBW), with minimal porosity, of .75 inch (19 mm) copper cross-sections; extensive 5-axis milling of water channels; electroplating of .37 inch (10 mm) thick OFE copper; tuning of the cavity by profiling beam noses prior to final joining with the cavity body; and machining of the cavity interior, are described here.

  15. Beam dynamics studies for transverse electromagnetic mode type rf deflectors

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

    Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

    2012-02-01

    We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the verticalmore »kick of the beam.« less

  16. Design Considerations for Future RF Circuits 1 Behzad Razavi

    E-Print Network [OSTI]

    Razavi, Behzad

    . I. INTRODUCTION The evolution of RF circuits has crossed an inflection point defined by two Current: 2 mA Conversion Gain: 5.4 dB NF: 8.2 dB IIP3: -3.8 dBm Supply Current: 2 mA Conversion Gain: 15 dB NF: 8.1 dB IIP3: +3.0 dBm 1 2 1 2 Fig. 1. (a) Active and (b) passive mixers operating with a 1-V

  17. Asymmetric Bimodal Accelerator Cavity for Raising rf Breakdown Thresholds

    SciTech Connect (OSTI)

    Kuzikov, S. V.; Kazakov, S. Yu.; Jiang, Y.; Hirshfield, J. L.

    2010-05-28

    We consider an axisymmetric microwave cavity for an accelerator structure whose eigenfrequency for its second lowest TM-like axisymmetric mode is twice that of the lowest such mode, and for which the fields are asymmetric along its axis. In this cavity, the peak amplitude of the rf electric field that points into either longitudinal face can be smaller than the peak field which points out. Computations show that a structure using such cavities might support an accelerating gradient about 47% greater than that for a structure using similar single-mode cavities, without an increase in breakdown probability.

  18. Surface Characterization of the LCLS RF Gun Cathode

    SciTech Connect (OSTI)

    Brachmann, Axel; Decker, Franz-Josef; Ding, Yuantao; Dowell, David; Emma, Paul; Frisch, Josef; Gilevich, Sasha; Hays, Gregory; Hering, Philippe; Huang, Zhirong; Iverson, Richard; Loos, Henrik; Miahnahri, Alan; Nordlund, Dennis; Nuhn, Heinz-Dieter; Pianetta, Piero; Turner, James; Welch, James; White, William; Wu, Juhao; Xiang, Dao; /SLAC

    2012-06-25

    The first copper cathode installed in the LCLS RF gun was used during LCLS commissioning for more than a year. However, after high charge operation (> 500 pC), the cathode showed a decline of quantum efficiency within the area of drive laser illumination. They report results of SEM, XPS and XAS studies that were carried out on this cathode after it was removed from the gun. X-ray absorption and X-ray photoelectron spectroscopy reveal surface contamination by various hydrocarbon compounds. In addition they report on the performance of the second installed cathode with emphasis on the spatial distribution of electron emission.

  19. Glass antenna for RF-ion source operation

    DOE Patents [OSTI]

    Leung, Ka Ngo (Hercules, CA); Lee, Yung-Hee Yvette (Berkeley, CA); Perkins, Luke T. (Plainsboro, NJ)

    2000-01-01

    An antenna comprises a plurality of small diameter conductive wires disposed in a dielectric tube. The number and dimensions of the conductive wires is selected to improve the RF resistance of the antenna while also facilitating a reduction in thermal gradients that may create thermal stresses on the dielectric tube. The antenna may be mounted in a vacuum system using a low-stress antenna assembly that cushions and protects the dielectric tube from shock and mechanical vibration while also permitting convenient electrical and coolant connections to the antenna.

  20. Beam dynamics studies for transverse electromagnetic mode type rf deflectors

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

    Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

    2012-02-01

    We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the vertical kick of the beam.

  1. Evolution of ordered {omega} phases in (Zr{sub 3}Al)-Nb alloys

    SciTech Connect (OSTI)

    Tewari, R.; Mukhopadhyay, P.; Banerjee, S.; Bendersky, L.A.

    1999-03-10

    Microstructural investigations on rapidly solidified Zr{sub 3}Al based alloys (binary Zr{sub 3}Al and ternary Zr{sub 3}Al-3Nb and Zr{sub 3}Al-10Nb) have revealed some unusual phase transformation sequences. The Zr{sub 5}Al{sub 3} phase (D8{sub 8} structure) has been found to occur in both the rapidly solidified ternary alloys unlike in the rapidly solidified stoichiometric Zr{sub 3}Al alloy in which the ZrAl phase (B8{sub 2} structure) has been found to be present. The evolution of the D8{sub 8} phase, which could be regarded as one of the ordered derivatives of the {omega} phase, could be described in terms of a superimposition of replacive and displacive ordering waves in the {beta} phase. The orientation relationship between the {beta} and the D8{sub 8} phases has been established. The microstructural changes occurring in the rapidly solidified Zr{sub 3}Al-Nb alloys during aging have been examined. It has been found that on aging the D8{sub 8} phase gets transformed into the B8{sub 2} phase which, on continued aging, transforms to other metastable and equilibrium phases, depending upon the aging temperature. The observed sequence of phase transformations involving different structurally related phases has been along the direction of progressively close packed structures. The symmetry changes associated with the sequence of {omega} related transformations have been summarized in the form of a symmetry tree.

  2. HF-based etching processes for improving laser damage resistance of fused silica optical surfaces

    SciTech Connect (OSTI)

    Suratwala, T I; Miller, P E; Bude, J D; Steele, R A; Shen, N; Monticelli, M V; Feit, M D; Laurence, T A; Norton, M A; Carr, C W; Wong, L L

    2010-02-23

    The effect of various HF-based etching processes on the laser damage resistance of scratched fused silica surfaces has been investigated. Conventionally polished and subsequently scratched fused silica plates were treated by submerging in various HF-based etchants (HF or NH{sub 4}F:HF at various ratios and concentrations) under different process conditions (e.g., agitation frequencies, etch times, rinse conditions, and environmental cleanliness). Subsequently, the laser damage resistance (at 351 or 355 nm) of the treated surface was measured. The laser damage resistance was found to be strongly process dependent and scaled inversely with scratch width. The etching process was optimized to remove or prevent the presence of identified precursors (chemical impurities, fracture surfaces, and silica-based redeposit) known to lead to laser damage initiation. The redeposit precursor was reduced (and hence the damage threshold was increased) by: (1) increasing the SiF{sub 6}{sup 2-} solubility through reduction in the NH4F concentration and impurity cation impurities, and (2) improving the mass transport of reaction product (SiF{sub 6}{sup 2-}) (using high frequency ultrasonic agitation and excessive spray rinsing) away from the etched surface. A 2D finite element crack-etching and rinsing mass transport model (incorporating diffusion and advection) was used to predict reaction product concentration. The predictions are consistent with the experimentally observed process trends. The laser damage thresholds also increased with etched amount (up to {approx}30 {micro}m), which has been attributed to: (1) etching through lateral cracks where there is poor acid penetration, and (2) increasing the crack opening resulting in increased mass transport rates. With the optimized etch process, laser damage resistance increased dramatically; the average threshold fluence for damage initiation for 30 {micro}m wide scratches increased from 7 to 41 J/cm{sup 2}, and the statistical probability of damage initiation at 12 J/cm{sup 2} of an ensemble of scratches decreased from {approx}100 mm{sup -1} of scratch length to {approx}0.001 mm{sup -1}.

  3. Development of a new casting method to fabricate U–Zr alloy containing minor actinides

    SciTech Connect (OSTI)

    Jong Hwan Kim; Hoon Song; Hyung Tae Kim; Ki Hwan Kim; Chan Bock Lee; R. S. Fielding

    2014-01-01

    Metal fuel slugs of U–Zr alloys for a sodium-cooled fast reactor (SFR) have conventionally been fabricated using an injection casting method. However, casting alloys containing volatile radioactive constituents, such as Am, are problematic in a conventional injection casting method. As an alternative fabrication method, low pressure gravity casting has been developed. Casting soundness, microstructural characteristics, alloying composition, density, and fuel losses were evaluated for the following as-cast fuel slugs: U–10 wt% Zr, U–10 wt% Zr–5 wt% RE, and U–10 wt% Zr–5 wt% RE–5 wt% Mn. The U and Zr contents were uniform throughout the matrix, and impurities such as oxyen, carbon, and nitrogen satisfied the specification of total impurities less than 2,000 ppm. The appearance of the fuel slugs was generally sound, and the internal integrity was shown to be satisfactory based on gamma-ray radiography. In a volatile surrogate casting test, the U–Zr–RE–Mn fuel slug showed that nearly all of the manganese was retained when casting was done under an inert atmosphere.

  4. Results from ORNL Characterization of Zr02-500-AK2 - Surrogate TRISO Material

    SciTech Connect (OSTI)

    Hunn, John D [ORNL; Kercher, Andrew K [ORNL

    2005-06-01

    This document is a compilation of the characterization data for the TRISO-coated surrogate particle batch designated ZrO2-500-AK2 that was produced at Oak Ridge National Laboratory (ORNL) as part of the Advanced Gas Reactor Fuel Development and Qualification (AGR) program. The ZrO2-500-AK2 material contains nominally 500 {micro}m kernels of yttria-stabilized zirconia (YSZ) coated with all TRISO layers (buffer, inner pyrocarbon, silicon carbide, and outer pyrocarbon). The ZrO2-500-AK2 material was created for: (1) irradiation testing in the High Flux Isotope Reactor (HFIR) and (2) limited dissemination to laboratories as deemed appropriate to the AGR program. This material was created midway into a TRISO fuel development program to accommodate a sudden opportunity to perform irradiation testing on surrogate material. While the layer deposition processes were chosen based on the best technical understanding at the time, technical progress at ORNL has led to an evolution in the perceived optimal deposition conditions since the createion of ZrO2-500-AK2. Thus, ZrO2-500-AK2 contains a reasonable TRISO microstructure, but does differ significanly from currently produced TRISO surrogates and fuel at ORNL. In this document, characterization data of the ZrO2-500-AK2 surrogate includes: size, shape, coating thickness, and density.

  5. Results from ORNL characterization of ZrO2-500-AK2 - surrogate TRISO material

    SciTech Connect (OSTI)

    Kercher, Andrew K [ORNL; Hunn, John D [ORNL

    2005-06-01

    This document is a compilation of the characterization data for the TRISO-coated surrogate particles designated ZrO2-500-AK2 that was produced at Oak Ridge National Laboratory (ORNL) as part of the Advanced Gas Reactor Fuel Development and Qualification (AGR) program. The ZrO2-500-AK2 material contains nominally 500 {micro}m kernels of yttria-stabilized zirconia (YSZ) coated with all TRISO layers (buffer, inner pyrocarbon, silicon carbide, and outer pyrocarbon). The ZrO2-500-AK2 material was created for: (1) irradiation testing in the High Flux Isotope Reactor (HFIR) and (2) limited dissemination to laboratories as deemed appropriate to the AGR program. This material was created midway into a TRISO fuel development program to accommodate a sudden opportunity to perform irradiation testing on surrogate material. While the layer deposition processes were chosen based on the best technical understanding at the time, technical progress at ORNL has led to an evolution in the perceived optimal deposition conditions since the creation of ZrO2-500-AK2. Thus, ZrO2-500-AK2 contains a reasonable TRISO microstructure, but does differ significantly from currently produced TRISO surrogates and fuel at ORNL. In this document, characterization data of the ZrO2-500-AK2 surrogate includes: size, shape, coating thickness, and density.

  6. Deposition and characterization of TiZrV-Pd thin films by dc magnetron sputtering

    E-Print Network [OSTI]

    Wang, Jie; Xu, Yan-Hui; Wei, Wei; Fan, Le; Pei, Xiang-Tao; Hong, Yuan-Zhi; Wang, Yong

    2015-01-01

    TiZrV film is mainly applied in the ultra-high vacuum pipe of storage ring. Thin film coatings of palladium which was added onto the TiZrV film to increase the service life of nonevaporable getters and enhance pumping speed for H2, was deposited on the inner face of stainless steel pipes by dc magnetron sputtering using argon gas as the sputtering gas. The TiZrV-Pd film properties were investigated by atomic force microscope (AFM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-Ray Diffraction (XRD). The grain size of TiZrV and Pd film were about 0.42~1.3 nm and 8.5~18.25 nm respectively. It was found that the roughness of TiZrV films was small, about 2~4 nm, for Pd film it is large, about 17~19 nm. PP At. % of Pd in TiZrV/Pd films varied from 86.84 to 87.56 according to the XPS test results.

  7. Cancellation of RF Coupler-Induced Emittance Due to Astigmatism

    E-Print Network [OSTI]

    Dowell, David H

    2015-01-01

    It is well-known that the electron beam quality required for applications such as FELs and ultra-fast electron diffraction can be degraded by the asymmetric fields introduced by the RF couplers of superconducting linacs. This effect is especially troublesome in the injector where the low energy beam from the gun is captured into the first high gradient accelerator section. Unfortunately modifying the established cavity design is expensive and time consuming, especially considering that only one or two sections are needed for an injector. Instead, it is important to analyze the coupler fields to understand their characteristics and help find less costly solutions for their cancellation and mitigation. This paper finds the RF coupler-induced emittance for short bunches is mostly due to the transverse spatial sloping or tilt of the field, rather than the field's time-dependence. It is shown that the distorting effects of the coupler can be canceled with a static (DC) quadrupole lens rotated about the z-axis.

  8. RF System Modeling for the CEBAF Energy Upgrade

    SciTech Connect (OSTI)

    Tomasz Plawski, J. Hovater

    2009-05-01

    An RF system model, based on MATLAB/SIMULINK, has been developed for analyzing the basic characteristics of the low level RF (LLRF) control system being designed for the CEBAF 12 GeV Energy Upgrade. In our model, a typical passband cavity representation is simplified to in-phase and quadrature (I&Q) components. Lorentz Force and microphonic detuning are incorporated as a new quadrature carrier frequency (frequency modulation). Beam is also represented as in-phase and quadrature components and superpositioned with the cavity field vector. Signals pass through two low pass filters, where the cutoff frequency is equal to half of the cavity bandwidth, then they are demodulated using the same detuning frequency. Because only baseband I&Q signals are calculated, the simulation process is very fast when compared to other controller-cavity models. During the design process we successfully analyzed gain requirements vs. field stability for different superconducting cavity microphonic backgrounds and Lorentz Force coefficients. Moreover, we were able to evaluate different types of a LLRF system’s control algorithm: GDR (Generator Driven Resonator) and SEL (Self Excited Loop) [1] as well as klystron power requirements for different cavities and beam loads.

  9. Current-induced spin-orbit torque switching of perpendicularly magnetized Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} structures

    SciTech Connect (OSTI)

    Akyol, Mustafa; Yu, Guoqiang; Alzate, Juan G.; Upadhyaya, Pramey; Li, Xiang; Wong, Kin L.; Khalili Amiri, Pedram; Wang, Kang L.; Ekicibil, Ahmet

    2015-04-20

    We study the effect of the oxide layer on current-induced perpendicular magnetization switching properties in Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} tri-layers. The studied structures exhibit broken in-plane inversion symmetry due to a wedged CoFeB layer, resulting in a field-like spin-orbit torque (SOT), which can be quantified by a perpendicular (out-of-plane) effective magnetic field. A clear difference in the magnitude of this effective magnetic field (H{sub z}{sup FL}) was observed between these two structures. In particular, while the current-driven deterministic perpendicular magnetic switching was observed at zero magnetic bias field in Hf|CoFeB|MgO, an external magnetic field is necessary to switch the CoFeB layer deterministically in Hf|CoFeB|TaO{sub x}. Based on the experimental results, the SOT magnitude (H{sub z}{sup FL} per current density) in Hf|CoFeB|MgO (?14.12?Oe/10{sup 7} A cm{sup ?2}) was found to be almost 13× larger than that in Hf|CoFeB|TaO{sub x} (?1.05?Oe/10{sup 7} A cm{sup ?2}). The CoFeB thickness dependence of the magnetic switching behavior, and the resulting ?H{sub z}{sup FL} generated by in-plane currents are also investigated in this work.

  10. Particle-In-Cell/Monte Carlo Simulation of Ion Back BomBardment in a High Average Current RF Photo-Gun

    E-Print Network [OSTI]

    Qiang, J.

    2010-01-01

    High Average Current RF Photo-Gun J. Qiang Lawrence Berkeleycurrent radio-frequency (RF) photo-gun using a particle-in-of high average current RF photo-guns have been proposed or

  11. RF propagation in an HVAC duct system: impulse response characteristics of the channel

    E-Print Network [OSTI]

    Stancil, Daniel D.

    RF propagation in an HVAC duct system: impulse response characteristics of the channel Pavel V, the heating, ventilation, and air conditioning (HVAC) duct system in buildings is a complex network of hollow at RF and microwave frequencies of com- mon interest. HVAC ducts can be used as a wireless communication

  12. Balanced optical-microwave phase detector for sub-femtosecond optical-RF synchronization

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

    Peng, Michael Y.; Kalaydzhyan, Aram; Kärtner, Franz X.

    2014-10-23

    We demonstrate that balanced optical-microwave phase detectors (BOMPD) are capable of optical-RF synchronization with sub-femtosecond residual timing jitter for large-scale timing distribution systems. RF-to-optical synchronization is achieved with a long-term stability of more »suppression ratio with potential improvement via DC offset adjustment.« less

  13. Bio-implantable passive on-chip RF-MEMS strain sensing resonators for orthopaedic applications

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Bio-implantable passive on-chip RF-MEMS strain sensing resonators for orthopaedic applications. Micromech. Microeng. 18 (2008) 115017 (9pp) doi:10.1088/0960-1317/18/11/115017 Bio-implantable passive on designed novel, bio-implantable, passive, on-chip, RF-MEMS strain sensors that rely on the resonance

  14. Study of high pressure gas filled RF cavities for muon collider

    E-Print Network [OSTI]

    Yonehara, Katsuya

    2015-01-01

    Muon collider is a considerable candidate of the next-generation high-energy lepton collider machine. Operating an RF cavity in a multi-Tesla magnet is a critical requirement in a muon accelerator and a cooling channel. However, the maximum RF gradient in a vacuum RF cavity is strongly limited by an external magnetic field. Dense hydrogen gas filled RF cavity has been proposed since it is functional of generating a high RF accelerating gradient in a strong magnetic field and making an ionization cooling process at the same time. A critical issue of the cavity is a beam- induced plasma that consumes a considerable amount of RF power. The gas filled RF test cell was made and measured the RF loading due to a beam-induced plasma by using an intense proton beam at Fermilab. By doping an electronegative gas in dense hydrogen, the plasma loading effect is significantly mitigated. The result shows that the cavity is functional with a muon collider beam. Recent progress is shown in this presentation.

  15. Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna

    SciTech Connect (OSTI)

    Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M.

    2011-12-23

    RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.

  16. A Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source

    E-Print Network [OSTI]

    the arc discharge. Consider instead a non-emitting plasma cathode in which the plasma is produced by rfA Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source and Nathaniel J. Fisch 3 Princeton University Plasma Physics Laboratory, Princeton, NJ 08540, USA Abstract

  17. Modeling and Design of RF MEMS Structures Using Computationally Efficient Numerical Techniques

    E-Print Network [OSTI]

    Tentzeris, Manos

    Modeling and Design of RF MEMS Structures Using Computationally Efficient Numerical Techniques N. A Abstract The modeling of MEMS structures using MRTD is presented. Many complex RF structures have been communication systems efficiently and accurately. Specifically, micromachined structures such as MEMS

  18. Modeling of Large Scale RF-MEMS Circuits Using Efficient Time-Domain Techniques

    E-Print Network [OSTI]

    Tentzeris, Manos

    Modeling of Large Scale RF-MEMS Circuits Using Efficient Time-Domain Techniques N. Bushyager, E Engineering Georgia Institute of Technology Atlanta, GA 30332-0250, USA Abstract RF-MEMS design is made difficult due to the lack of tools capable of simulating both MEMS devices and their surrounding circuits

  19. Ferroelectric PZT RF MEMS Resonators Jeffrey S. Pulskamp, Sarah S. Bedair, Ronald G.

    E-Print Network [OSTI]

    Afshari, Ehsan

    Ferroelectric PZT RF MEMS Resonators Jeffrey S. Pulskamp, Sarah S. Bedair, Ronald G. Polcawich- piezoelectric lead zirconate titanate (PZT) RF MEMS resonators. Several research topics are introduced including (~117dB) parallel resonant mode with DC bias tunable rejection, a MEMS support design for the mitigation

  20. Reliability of Capacitive RF MEMS Switches at High and Low Temperatures

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Reliability of Capacitive RF MEMS Switches at High and Low Temperatures Yong Zhu, Horacio D 60208-3111 Received 1 September 2003; accepted 24 February 2003 ABSTRACT: Some applications of RF MEMS temperatures in the range 60°C to 100°C are envisioned. The basic operation of a capacitive MEMS switch

  1. TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities

    E-Print Network [OSTI]

    TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities F. Marhauser BESSY GmbH #12;TESLA FEL Report 200602 Contents 1. INTRODUCTION......................................................................................................................................................28 #12;TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities F

  2. Study of lithium diffusion in RF sputtered Nickel/Vanadium mixed oxides thin films

    E-Print Network [OSTI]

    Artuso, Florinda

    Study of lithium diffusion in RF sputtered NickelÁ/Vanadium mixed oxides thin films F. Artuso a lithium insertion inside RF sputtered Ni/V mixed oxides thin films have been investigated employing, showed three steps clearly involved in the intercalation mechanism of lithium in the oxide films: (i

  3. Dependence of nuclear spin singlet lifetimes on RF spin-locking power

    E-Print Network [OSTI]

    Stephen J. DeVience; Ronald L. Walsworth; Matthew S. Rosen

    2012-01-06

    We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that in many biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.

  4. Dependence of nuclear spin singlet lifetimes on RF spin-locking power

    E-Print Network [OSTI]

    DeVience, Stephen J; Rosen, Matthew S

    2012-01-01

    We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that in many biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.

  5. Nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging

    DOE Patents [OSTI]

    Fukushima, Eiichi (Los Alamos, NM); Roeder, Stephen B. W. (La Mesa, CA); Assink, Roger A. (Albuquerque, NM); Gibson, Atholl A. V. (Bryan, TX)

    1986-01-01

    An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio-frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

  6. Bio-corrosion and cytotoxicity studies on novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses

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

    Vincent, S.; Daiwile, A.; Devi, S. S.; Kramer, M. J.; Besser, M. F.; Murty, B. S.; Bhatt, Jatin

    2014-09-26

    Metallic glasses are a potential and compatible implant candidate for biomedical applications. In the present investigation, a comparative study between novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses is carried out to evaluate in vitro biocompatibility using simulated body fluids. The bio-corrosion behavior of Zr- and Cu-based metallic glasses in different types of artificial body fluids such as artificial saliva solution, phosphate-buffered saline solution, artificial blood plasma solution, and Hank’s balanced saline solution is evaluated using potentiodynamic polarization studies at a constant body temperature of 310.15 K (37 °C). Surface morphology of samples after bio-corrosion experiments was observed by scanning electron microscopy.more »In vitro cytotoxicity test on glassy alloys were performed using human osteosarcoma cell line as per 10993-5 guidelines from International Organization for Standardization. As a result, the comparative study between Zr- and Cu-based glassy alloys provides vital information about the effect of elemental composition on biocompatibility of metallic glasses.« less

  7. Determination of the direct double- ? -decay Q value of Zr 96 and atomic masses of Zr 90 - 92 , 94 , 96 and Mo 92 , 94 - 98 , 100

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

    Gulyuz, K.; Ariche, J.; Bollen, G.; Bustabad, S.; Eibach, M.; Izzo, C.; Novario, S. J.; Redshaw, M.; Ringle, R.; Sandler, R.; et al

    2015-05-06

    Experimental searches for neutrinoless double-? decay offer one of the best opportunities to look for physics beyond the standard model. Detecting this decay would confirm the Majorana nature of the neutrino, and a measurement of its half-life can be used to determine the absolute neutrino mass scale. Important to both tasks is an accurate knowledge of the Q value of the double-? decay. The LEBIT Penning trap mass spectrometer was used for the first direct experimental determination of the ??Zr double-? decay Q value: Q??=3355.85(15) keV. This value is nearly 7 keV larger than the 2012 Atomic Mass Evaluation [M.more »Wang et al., Chin. Phys. C 36, 1603 (2012)] value and one order of magnitude more precise. The 3-? shift is primarily due to a more accurate measurement of the ??Zr atomic mass: m(??Zr)=95.90827735(17) u. Using the new Q value, the 2???-decay matrix element, |M2?|, is calculated. Improved determinations of the atomic masses of all other zirconium (90-92,94,96Zr) and molybdenum (92,94-98,100Mo) isotopes using both ¹²C? and ??Rb as references are also reported.« less

  8. Experimental constraints on the $?$-ray strength function in $^{90}$Zr using partial cross sections of the $^{89}$Y(p,$?$)$^{90}$Zr reaction

    E-Print Network [OSTI]

    L. Netterdon; A. Endres; S. Goriely; J. Mayer; P. Scholz; M. Spieker; A. Zilges

    2015-04-20

    Partial cross sections of the $^{89}$Y(p,$\\gamma$)$^{90}$Zr reaction have been measured to investigate the $\\gamma$-ray strength function in the neutron-magic nucleus $^{90}$Zr. For five proton energies between $E_p=3.65$ MeV and $E_p=4.70$ MeV, partial cross sections for the population of seven discrete states in $^{90}$Zr have been determined by means of in-beam $\\gamma$-ray spectroscopy. Since these $\\gamma$-ray transitions are dominantly of $E1$ character, the present measurement allows an access to the low-lying dipole strength in $^{90}$Zr. A $\\gamma$-ray strength function based on the experimental data could be extracted, which is used to describe the total and partial cross sections of this reaction by Hauser-Feshbach calculations successfully. Significant differences with respect to previously measured strength functions from photoabsorption data point towards deviations from the Brink-Axel hypothesis relating the photo-excitation and de-excitation strength functions.

  9. Ferroelectric performances and crystal structures of (Pb, La)(Zr, Ti, Nb)O{sub 3}

    SciTech Connect (OSTI)

    Kitamura, Naoto [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Division of Ecosystem Research, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Mizoguchi, Takuma [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Itoh, Takanori [AGC Seimi Chemical Co., Ltd., 3-2-10 Chigasaki-City, Kanagawa 253-8585 (Japan); Idemoto, Yasushi, E-mail: idemoto@rs.noda.tus.ac.jp [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Division of Ecosystem Research, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

    2014-02-15

    In this study, we focused on Nb and La substituted Pb(Zr, Ti)O{sub 3}: i.e., (Pb, La)(Zr, Ti, Nb)O{sub 3}. As for the samples, dependences of ferroelectric properties on La and Nb compositions were examined. In addition, the crystal structures were analyzed by the Rietveld method, and then a relationship between the metal compositions and the crystal structures were discussed. From P–E hysteresis loop measurements, it was found that the remanant polarization of Pb(Zr, Ti)O{sub 3} was increased by both the La and Nb substitutions although the heavy substitution of La had an undesirable effect. It was also indicated that the Curie temperature decreased with increasing La content. The Rietveld analysis using synchrotron X-ray diffraction patterns demonstrated that the structure distortion was relaxed by the La and Nb substitutions. Such a change in the crystals was well consistent with the harmful effects on the Curie temperature and the remanent polarization by the heavy La substitution. - Graphical abstract: Rietveld refinement pattern of 2 mol% PbSiO{sub 3}-added Pb{sub 0.95}La{sub 0.05}Zr{sub 0.50}Ti{sub 0.45}Nb{sub 0.05}O{sub 3} (synchrotron X-ray diffraction). Display Omitted - Highlights: • (Pb,La)(Zr,Ti,Nb)O{sub 3} were successfully synthesized. • Remanant polarization of Pb(Zr,Ti)O{sub 3} was improved by substitutions of La and Nb. • Crystal structures of (Pb,La)(Zr,Ti,Nb)O{sub 3} were refined and the distortions were estimated.

  10. Investigation of Interdiffusion Behavior in the Mo-Zr Binary System via Diffusion Couple Studies

    SciTech Connect (OSTI)

    A. Paz y Puente; J. Dickson; D.D. Keiser, Jr.; Y.H. Sohn

    2014-03-01

    Zirconium has recently garnered attention for use as a diffusion barrier between U–Mo metallic nuclear fuels and Al alloy cladding. In order to gain a fundamental understanding of the diffusional interactions, the interdiffusion behavior in the binary Mo–Zr system was investigated via solid-to-solid diffusion couples annealed in the temperature range of 750 to 1050 degrees C. A combination of scanning electron microscopy, X-ray energy dispersive spectroscopy, and electron probe microanalysis were used to examine the microstructure and concentration profiles across the interdiffusion zone. A large __-Zr (cI2) solid solution layer and a thin (approximately 1–2 um) layer of Mo2Zr (cF24) developed in all couples. Parabolic growth constants and concentration dependent interdiffusion coefficients were calculated for the Mo2Zr and Zr solid solution phases, respectively. The pre-exponential factor and activation energy for growth of the Mo2Zr phase were determined to be approximately 6.5 × 10- 15 m2/s and 90 kJ/mol, respectively. The interdiffusion coefficient in ___-Zr solid solution decreased with an increase in Mo concentration. Both the pre-exponential factors (2 × 10- 8 m2/s at 2 at.% Mo to near 5 × 10- 8 m2/s at 9 at.% Mo) and activation energies (140 kJ/mol at 2 at.% Mo to approximately 155 kJ/mol at 9 at.% Mo) of interdiffusion coefficients were determined to increase with an increase in Mo concentration.

  11. Report of the survey realized at the TIARA workshop on RF power generation, Uppsala, 17-19 June 2013

    E-Print Network [OSTI]

    Tanguy, C.

    2013-01-01

    Report of the survey realized at the TIARA workshop on RF power generation, Uppsala, 17-19 June 2013

  12. The effects of zirconia morphology on methanol synthesis from COand H2 over Cu/ZrO2 catalysts: Part I -- Steady-State Studies

    SciTech Connect (OSTI)

    Rhodes, Michael J.; Bell, Alexis T.

    2005-03-21

    The effect of zirconia phase on the activity and selectivityof Cu/ZrO2 for the hydrogenation of CO has been investigated. Relativelypure t-ZrO2 and m-ZrO2 were prepared with high surface areas (~; 145m2/g). Copper was then deposited onto the surface of these materials byeither incipient-wetness impregnation or deposition-precipitation. For afixed Cu surface area, Cu/m-ZrO2 was tenfold more active for methanolsynthesis than Cu/t-ZrO2 from a feed of 3/1 H2/CO at 3.0 MPa andtemperatures between 473 and 523 K. Cu/m-ZrO2 also exhibited a higherselectivity to methanol. Increasing the Cu surface area on m-ZrO2resulted in further improvement in activity with minimal change inselectivity. Methanol productivity increased linearly for both Cu/t-ZrO2and Cu/m-ZrO2 with increasing Cu surface area. The difference in inherentactivity of each phase paralleled the stronger and larger CO adsorptioncapacity of the Cu/m-ZrO2 as quantified by CO-TPD. The higher COadsorption capacity of Cu/m-ZrO2 is attributed to the presence of a highconcentration of anionic vacancies on the surface of m-ZrO2. Suchvacancies expose cus-Zr4+ cations, which act as Lewis acid centers andenhance the Bronsted acidity of adjacent Zr-OH groups. The presence ofcus-Zr4+ sites and adjacent Bronsted acidic Zr-OH groups contributes tothe adsorption of CO as HCOO-Zr groups, which are the initial precursorsto methanol.

  13. Reflective Cracking Study: First-level Report on HVS Testing on Section 587RF - 45 mm RAC-G Overlay

    E-Print Network [OSTI]

    Wu, R; Jones, David; Harvey, John T

    2008-01-01

    Testing on Section 589RF — 45 mm MB4-G Overlay (UCPRC-RR-Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-Testing on Section 588RF — 90 mm AR4000-D Overlay (UCPRC-RR-

  14. Reflective Cracking Study: First-level Report on HVS Testing on Section 586RF - 45 mm MB15-GOverlay

    E-Print Network [OSTI]

    Jones, David; Wu, R; Harvey, John T

    2008-01-01

    Testing on Section 590RF — 90 mm MB4-G Overlay (UCPRC-RR-Testing on Section 589RF — 45 mm MB4-G Overlay (UCPRC-RR-Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-

  15. Reflective Cracking Study: First-Level Report on HVS Testing on Section 589RF - 45 mm MB4-G Overlay

    E-Print Network [OSTI]

    Jones, David; Harvey, John T; Wu, R; Lea, J.

    2008-01-01

    Testing on Section 590RF — 90 mm MB4-G Overlay (UCPRC-RR-Testing on Section 589RF — 45 mm MB4-G Overlay (UCPRC-RR-Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-

  16. Reflective Cracking Study: First-Level Report on HVS Testing on Section 590RF - 90 mm MB4-G Overlay

    E-Print Network [OSTI]

    Jones, David; Tsai, Bor-Wen; Harvey, John T

    2008-01-01

    Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-Testing on Section 588RF — 90 mm AR4000-D Overlay (UCPRC-RR-Testing on Section 586RF — 45 mm MB15-G Overlay (UCPRC-RR-

  17. Reflective Cracking Study: First-level Report on HVS Testing on Section 588RF - 90 mm AR4000-DOverlay

    E-Print Network [OSTI]

    Jones, David; Wu, R; Harvey, John T

    2008-01-01

    Testing on Section 590RF — 90 mm MB4-G Overlay (UCPRC-RR-Testing on Section 589RF — 45 mm MB4-G Overlay (UCPRC-RR-Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-

  18. ON THE FREQUENCY SCALINGS OF RF GUNS Leon C.-L. Lin, J. S. Wurtele, and S. C. Chen

    E-Print Network [OSTI]

    Wurtele, Jonathan

    ON THE FREQUENCY SCALINGS OF RF GUNS Leon C.-L. Lin, J. S. Wurtele, and S. C. Chen Plasma Fusion Center Massachusetts Institute of Technology Abstract A frequency scaling law for RF guns is derived from the nor- malized Vlasov-Maxwell equations. It shows that higher fre- quency RF guns can generate higher

  19. Efficient Broadband RF Energy Harvesting for Wireless Sensors Joseph A. Hagerty, Tian Zhao, Regan Zane and Zoya Popovic

    E-Print Network [OSTI]

    Efficient Broadband RF Energy Harvesting for Wireless Sensors Joseph A. Hagerty, Tian Zhao, Regan. · the last section discusses application examples of RF energy harvesting in wireless sensors. RF Power an approach to wireless power delivery and subsequent power management for low-power batteryless sensors

  20. Simulations of the rf heating rates in a linear quadrupole ion trap Vladimir L. Ryjkov,* XianZhen Zhao,

    E-Print Network [OSTI]

    Schuessler, Hans

    Simulations of the rf heating rates in a linear quadrupole ion trap Vladimir L. Ryjkov,* Xian, trapping voltage, and the number of ions is studied. The dependence of rf heating rate on temperature shows. The rf heating rate is shown to increase very sharply with the amplitude of the trapping voltage

  1. Low Actuation Voltage RF MEMS SwitchesWith Signal Frequencies From 0.25GHz to 40GHz

    E-Print Network [OSTI]

    Shen, Shyh-Chiang

    Low Actuation Voltage RF MEMS SwitchesWith Signal Frequencies From 0.25GHz to 40GHz Shyh-voltage radio-frequency micro- electromechanical system (RF MEMS) switch is reported. The device switching of better than 27 dB over the frequency band from 0.25GHz to 40GHz was achieved. The RF MEMS switch

  2. Reconfigurable Multi-Beam Spiral Antenna with RF-MEMS Capacitive Series Switches Fabricated on Rigid Substrates

    E-Print Network [OSTI]

    De Flaviis, Franco

    Reconfigurable Multi-Beam Spiral Antenna with RF-MEMS Capacitive Series Switches Fabricated antenna, which radiates multi-beam with radio frequency-micro electro mechanical system (RF-MEMS.8). The spiral is configured by three-arms, which can be interconnected by two RF-MEMS series switches

  3. TESLA-FEL Report 2005-06 DIGITAL LOW LEVEL RF CONTROL SYSTEM FOR THE DESY TTF

    E-Print Network [OSTI]

    TESLA-FEL Report 2005-06 DIGITAL LOW LEVEL RF CONTROL SYSTEM FOR THE DESY TTF VUV-FEL LINAC Valeri Electron Laser (VUV-FEL) Linac each klystron supplies RF power to up to 32 cavities. The superconducting. The VUV-FEL Linac RF control system employs a completely digital feedback system to provide flexibility

  4. Superconducting DC and RF Properties of Ingot Niobium

    SciTech Connect (OSTI)

    Pashupati Dhakal, Gianluigi Ciovati, Peter Kneisel, Ganapati Rao Myneni

    2011-07-01

    The thermal conductivity, DC magnetization and penetration depth of large-grain niobium hollow cylindrical rods fabricated from ingots, manufactured by CBMM subjected to chemical and heat treatment were measured. The results confirm the influence of chemical and heat-treatment processes on the superconducting properties, with no significant dependence on the impurity concentrations in the original ingots. Furthermore, RF properties, such as the surface resistance and quench field of the niobium rods were measured using a TE{sub 011} cavity. The hollow niobium rod is the center conductor of this cavity, converting it to a coaxial cavity. The quench field is limited by the critical heat flux through the rods' cooling channel.

  5. RF and structural characterization of new SRF films

    SciTech Connect (OSTI)

    A.-M. Valente-Feliciano,H. L. Phillips,C. E. Reece,X. Zhao,D. Gu,R. Lukaszew,B. Xiao,K. Seo

    2009-09-01

    In the past years, energetic vacuum deposition methods have been developed in different laboratories to improve Nb/Cu technology for superconducting cavities. Jefferson Lab is pursuing energetic condensation deposition via Electron Cyclotron Resonance. As part of this study, the influence of the deposition energy on the material and RF properties of the Nb thin film is investigated. The film surface and structure analyses are conducted with various techniques like X-ray diffraction, Transmission Electron Microscopy, Auger Electron Spectroscopy and RHEED. The microwave properties of the films are characterized on 50 mm disk samples with a 7.5 GHz surface impedance characterization system. This paper presents surface impedance measurements in correlation with surface and material characterization for Nb films produced on copper substrates with different bias voltages and also highlights emerging opportunities for developing multilayer SRF films with a new deposition system.

  6. 1.3 GHz superconducting RF cavity program at Fermilab

    SciTech Connect (OSTI)

    Ginsburg, C.M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L.; Cooper, C.; Foley, M.; Ge, M.; Grimm, C.; Harms, E.; /Fermilab

    2011-03-01

    At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

  7. The Development of the Linac Coherent Light Source RF Gun

    E-Print Network [OSTI]

    Dowell, David H; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling

    2015-01-01

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL). In addition to many other stringent requirements, the LCLS XFEL requires extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. This paper describes the analysis and design improvements of the BNL/SLAC/UCLA s-band gun leading to achievement of the LCLS performance goals.

  8. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    SciTech Connect (OSTI)

    Poole, B R; Harris, J R

    2011-03-07

    The Naval Postgraduate School (NPS), Niowave, Inc., and Boeing have recently demonstrated operation of the first superconducting RF electron gun based on a quarter wave resonator structure. In preliminary tests, this gun has produced 10 ps long bunches with charge in excess of 78 pC, and with beam energy up to 396 keV. Initial testing occurred at Niowave's Lansing, MI facility, but the gun and diagnostic beam line are planned for installation in California in the near future. The design of the diagnostic beam line is conducive to the addition of a Cerenkov radiator without interfering with other beam line operations. Design and simulations of a Cerenkov radiator, consisting of a dielectric lined waveguide will be presented. The dispersion relation for the structure is determined and the beam interaction is studied using numerical simulations. The characteristics of the microwave radiation produced in both the short and long bunch regimes will be presented.

  9. National RF Test Facility as a multipurpose development tool

    SciTech Connect (OSTI)

    McManamy, T.J.; Becraft, W.R.; Berry, L.A.; Blue, C.W.; Gardner, W.L.; Haselton, H.H.; Hoffman, D.J.; Loring, C.M. Jr.; Moeller, F.A.; Ponte, N.S.

    1983-01-01

    Additions and modifications to the National RF Test Facility design have been made that (1) focus its use for technology development for future large systems in the ion cyclotron range of frequencies (ICRF), (2) expand its applicability to technology development in the electron cyclotron range of frequencies (ECRF) at 60 GHz, (3) provide a facility for ELMO Bumpy Torus (EBT) 60-GHz ring physics studies, and (4) permit engineering studies of steady-state plasma systems, including superconducting magnet performance, vacuum vessel heat flux removal, and microwave protection. The facility will continue to function as a test bed for generic technology developments for ICRF and the lower hybrid range of frequencies (LHRF). The upgraded facility is also suitable for mirror halo physics experiments.

  10. A new microphonics measurement method for superconducting RF cavities

    SciTech Connect (OSTI)

    Gao,Zheng; He,Yuan; Chang,Wei; Powers, Tom [JLAB; Yue,Wei-ming; Zhu,Zheng-long; Chen,Qi

    2014-09-01

    Mechanical vibrations of the superconducting cavity, also known as microphonics, cause shifts in the resonant frequency of the cavity. In addition to requiring additional RF power, these frequency shifts can contribute to errors in the closed loop phase and amplitude regulation. In order to better understand these effects, a new microphonics measurement method was developed, and the method was successfully used to measure microphonics on the half-wave superconducting cavity when it was operated in a production style cryostat. The test cryostat held a single ?=0.1 half-wave cavity which was operated at 162.5 MHz [1] and [2]. It's the first time that the National Instruments PXIe-5641R intermediate frequency transceiver has been used for microphonics measurements in superconducting cavities. The new microphonics measurement method and results will be shown and analyzed in this paper.

  11. Infrared study on room-temperature atomic layer deposition of HfO{sub 2} using tetrakis(ethylmethylamino)hafnium and remote plasma-excited oxidizing agents

    SciTech Connect (OSTI)

    Kanomata, Kensaku [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan and Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Ohba, Hisashi; Pungboon Pansila, P.; Ahmmad, Bashir; Kubota, Shigeru; Hirahara, Kazuhiro; Hirose, Fumihiko, E-mail: fhirose@yz.yamagata-u.ac.jp [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510 (Japan)

    2015-01-01

    Room-temperature atomic layer deposition (ALD) of HfO{sub 2} was examined using tetrakis (ethylmethylamino)hafnium (TEMAH) and remote plasma-excited water and oxygen. A growth rate of 0.26?nm/cycle at room temperature was achieved, and the TEMAH adsorption and its oxidization on HfO{sub 2} were investigated by multiple internal reflection infrared absorption spectroscopy. It was observed that saturated adsorption of TEMAH occurs at exposures of ?1?×?10{sup 5}?L (1 L?=?1?×?10{sup ?6} Torr s) at room temperature, and the use of remote plasma-excited water and oxygen vapor is effective in oxidizing the TEMAH molecules on the HfO{sub 2} surface, to produce OH sites. The infrared study suggested that Hf–OH plays a role as an adsorption site for TEMAH. The reaction mechanism of room temperature HfO{sub 2} ALD is discussed in this paper.

  12. Transfer couplings and hindrance far below the barrier for 40 Ca + 96 Zr

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

    Stefanini, A. M.; Montagnoli, G.; Esbensen, H.; Corradi, L.; Courtin, S.; Fioretto, E.; Goasduff, A.; Grebosz, J.; Haas, F.; Mazzocco, M.; et al

    2015-01-29

    The sub-barrier fusion excitation function of 40Ca + 96Zr has been measured down to cross sections ?2.4µb, i.e. two orders of magnitude smaller than obtained in the previous experiment, where the sub-barrier fusion of this system was found to be greatly enhanced with respect to 40Ca + 90Zr, and the need of coupling to transfer channels was suggested. The purpose of this work was to investigate the behavior of 40Ca + 96Zr fusion far below the barrier. The smooth trend of the excitation function has been found to continue, and the logarithmic slope increases very slowly. No indication of hindrancemore »shows up, and a comparison with 48Ca + 96Zr is very useful in this respect. A new CC analysis of the complete excitation function has been performed, including explicitly one- and two-nucleon Q >0 transfer channels. Such transfer couplings bring significant cross section enhancements, even at the level of a few µb. Locating the hindrance threshold, if any, in 40Ca + 96Zr would require challenging measurements of cross sections in the sub-µb range.« less

  13. Melting temperatures of the ZrO{sub 2}-MOX system

    SciTech Connect (OSTI)

    Uchida, T.; Hirooka, S.; Kato, M.; Morimoto, K.; Sugata, H.; Shibata, K.; Sato, D.

    2013-07-01

    Severe accidents occurred at the Fukushima Daiichi Nuclear Power Plant Units 1-3 on March 11, 2011. MOX fuels were loaded in the Unit 3. For the thermal analysis of the severe accident, melting temperature and phase state of MOX corium were investigated. The simulated coriums were prepared from 4%Pu-containing MOX, 8%Pu-containing MOX and ZrO{sub 2}. Then X-ray diffraction, density and melting temperature measurements were carried out as a function of zirconium and plutonium contents. The cubic phase was observed in the 25%Zr-containing corium and the tetragonal phase was observed in the 50% and 75%Zr-containing coria. The lattice parameter and density monotonically changed with Pu content. Melting temperature increased with increasing Pu content; melting temperature were estimated to be 2932 K for 4%Pu MOX corium and 3012 K for 8%Pu MOX corium in the 25%ZrO{sub 2}-MOX system. The lowest melting temperature was observed for 50%Zr-containing corium. (authors)

  14. The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar

    E-Print Network [OSTI]

    Ellingson, Steven W.

    be an excellent receiver for solar radar, potentially demonstrating accurate geomagnetic storm prediction fromThe Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar A Ground-Based Instrument Paper for the 2010 NRC Decadal Survey of Solar and Space

  15. The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar

    E-Print Network [OSTI]

    Ellingson, Steven W.

    construction in New Mexico, and discuss the scientific goals of the project in the areas of solar, ionosphericThe Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar Namir E. Kassim Naval Research Laboratory, Washington, DC 20375 Stephen M. White AFRL

  16. PHYSICAL REVIEW C 83, 067303 (2011) Deformation and its influence on K isomerism in neutron-rich Hf nuclei

    E-Print Network [OSTI]

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    2011-01-01

    around N = 116, using configuration-constrained calculations of potential-energy surfaces. Despite having energy (2.4 MeV) in the isomer has been associated with proposals for a clean reservoir of nuclear energy reduced shape elongation, the multiquasiparticle states in 186,188 Hf remain moderately robust against

  17. Role of hydrogen in Ge/HfO2/Al gate stacks subjected to negative bias temperature instability

    E-Print Network [OSTI]

    Misra, Durgamadhab "Durga"

    Role of hydrogen in Ge/HfO2/Al gate stacks subjected to negative bias temperature instability N 2007; published online 17 January 2008 This work investigates the role of hydrogen and nitrogen in a Ge. Virtually unchanged interface state density as a function of NBTI indicates no atomic hydrogen release from

  18. Computational investigation of the phase stability and the electronic properties for Gd-doped HfO{sub 2}

    SciTech Connect (OSTI)

    Wang, L. G. [General Research Institute for Nonferrous Metals, Beijing 100088 (China); California Institute of Technology, Pasadena, California 91125 (United States); Xiong, Y.; Xiao, W.; Cheng, L.; Du, J.; Tu, H. [General Research Institute for Nonferrous Metals, Beijing 100088 (China); Walle, A. van de [Brown University, Providence, Rhode Island 02912 (United States); California Institute of Technology, Pasadena, California 91125 (United States)

    2014-05-19

    Rare earth doping is an important approach to improve the desired properties of high-k gate dielectric oxides. We have carried out a comprehensive theoretical investigation on the phase stability, band gap, formation of oxygen vacancies, and dielectric properties for the Gd-doped HfO{sub 2}. Our calculated results indicate that the tetragonal phase is more stable than the monoclinic phase when the Gd doping concentration is greater than 15.5%, which is in a good agreement with the experimental observations. The dopant's geometric effect is mainly responsible for the phase stability. The Gd doping enlarges the band gap of the material. The dielectric constant for the Gd-doped HfO{sub 2} is in the range of 20–30 that is suitable for high-k dielectric applications. The neutral oxygen vacancy formation energy is 3.2?eV lower in the doped material than in pure HfO{sub 2}. We explain the experimental observation on the decrease of photoluminescence intensities in the Gd-doped HfO{sub 2} according to forming the dopant-oxygen vacancy complexes.

  19. Analytical Potential Energy Surface for the Na + HF NaF + H reaction: Application of Conventional Transition-State Theory

    E-Print Network [OSTI]

    Analytical Potential Energy Surface for the Na + HF NaF + H reaction: Application of Conventional Transition-State Theory Alessandra F. A. Vilela, Ricardo Gargano a Patr´icia R.P. Barreto b a Instituto de from calculation of the rate constant using con- ventional Transition State Theory (TST

  20. Next Generation Fast RF Interlock Module and ATCA Adapter for ILC High Availability RF Test Station Demonstration

    SciTech Connect (OSTI)

    Larsen, R

    2009-10-17

    High availability interlocks and controls are required for the ILC (International Linear Collider) L-Band high power RF stations. A new F3 (Fast Fault Finder) VME module has been developed to process both fast and slow interlocks using FPGA logic to detect the interlock trip excursions. This combination eliminates the need for separate PLC (Programmable Logic Controller) control of slow interlocks. Modules are chained together to accommodate as many inputs as needed. In the next phase of development the F3's will be ported to the new industry standard ATCA (Advanced Telecom Computing Architecture) crate (shelf) via a specially designed VME adapter module with IPMI (Intelligent Platform Management Interface). The goal is to demonstrate auto-failover and hot-swap for future partially redundant systems.

  1. R&D activities on RF contacts for the ITER ion cyclotron resonance heating launcher

    E-Print Network [OSTI]

    Hillairet, Julien; Bamber, Rob; Beaumont, Bertrand; Bernard, Jean-Michel; Delaplanche, Jean-Marc; Durodié, Frédéric; Lamalle, Philippe; Lombard, Gilles; Nicholls, Keith; Shannon, Mark; Vulliez, Karl; Cantone, Vincent; Hatchressian, Jean-Claude; Lebourg, Philippe; Martinez, André; Mollard, Patrick; Mouyon, David; Pagano, Marco; Patterlini, Jean-Claude; Soler, Bernard; Thouvenin, Didier; Toulouse, Lionel; Verger, Jean-Marc; Vigne, Terence; Volpe, Robert

    2015-01-01

    Embedded RF contacts are integrated within the ITER ICRH launcher to allow assembling, sliding and to lower the thermo-mechanical stress. They have to withstand a peak RF current up to 2.5 kA at 55 MHz in steady-state conditions, in the vacuum environment of themachine.The contacts have to sustain a temperature up to 250{\\textdegree}Cduring several days in baking operations and have to be reliable during the whole life of the launcher without degradation. The RF contacts are critical components for the launcher performance and intensive R&D is therefore required, since no RF contactshave so far been qualified at these specifications. In order to test and validate the anticipated RF contacts in operational conditions, CEA has prepared a test platform consisting of a steady-state vacuum pumped RF resonator. In collaboration with ITER Organization and the CYCLE consortium (CYclotronCLuster for Europe), an R&D program has been conducted to develop RF contacts that meet the ITER ICRH launcher specification...

  2. Commissioning of the LHC Low Level RF System Remote Configuration Tools

    SciTech Connect (OSTI)

    Van Winkle, Daniel; /SLAC; Fox, John; /SLAC; Mastorides, Themis; /SLAC; Rivetta, Claudio; /SLAC; Baudrenghien, Philippe; /CERN; Butterworth, Andrew; /CERN; Molendijk, John; /CERN

    2010-08-26

    The LHC Low Level RF system (LLRF) is a complex multi-loop system used to regulate the superconductive cavity gap voltage as well as to reduce the impedance presented by RF stations to the beam. The RF system can have a profound impact on the stability of the beam; a mis-configured RF system has the potential of causing longitudinal instabilities, beam diffusion and beam loss. To configure the RF station for operation, a set of parameters in the LLRF multi-loop system have to be defined. Initial system commissioning as well as ongoing operation requires a consistent method of computer based remote measurement and model-based design of each RF station feedback system. This paper describes the suite of Matlab tools used for configuring the LHC RF system during the start up in Nov2009-Feb2010. We present a brief overview of the tool, examples of commissioning results, and basics of the model-based design algorithms. This work complements our previous presentation, where the algorithms and methodology followed in the tools were described.

  3. Pressurized H_{2} rf Cavities in Ionizing Beams and Magnetic Fields

    SciTech Connect (OSTI)

    Chung, M.; et al.

    2013-10-01

    A major technological challenge in building a muon cooling channel is operating RF cavities in multi-tesla external magnetic fields. We report the first experimental characterization of a high pressure gas-filled 805 MHz RF cavity for use with intense ionizing beams and strong external magnetic fields. RF power consumption by beam-induced plasma was investigated with hydrogen and deuterium gases with pressures between 20 and 100 atm and peak RF gradients between 5 and 50 MV/m. The energy absorption per ion pair-RF cycle ranges from 10?18 to 10?16 J. The low pressure case agrees well with an analytical model based on electron and ion mobilities. Varying concentrations of oxygen gas were investigated to remove free electrons from the cavity and reduce the RF power consumption. Measurements of the electron attachment time to oxygen and rate of ion-ion recombination were also made. Additionally, we demonstrate the operation of the gas-filled RF cavity in a solenoidal field of up to 3 T, finding no major magnetic field dependence. These results indicate that a high pressure gas-filled cavity is potentially a viable technology for muon ionization cooling.

  4. Remarkable Strontium B-Site Occupancy in Ferroelectric Pb(Zr1-xTix)O3 Solid Solutions Doped with Cryolite-Type Strontium Niobate

    E-Print Network [OSTI]

    Feltz, A.; Schmidt-Winkel, P.; Schossman, M.; Booth, C.H.; Albering, J.

    2007-01-01

    contains Lead-Titanium-Zirconium Oxide of Specificstructure such as lead zirconium titanium oxide Pb(Zr,Ti)O 3

  5. Irradiation-Enhanced Second-Phase Precipitation in Zr-Fe Nanocrystalline Thin Films , A. T. Motta1

    E-Print Network [OSTI]

    Motta, Arthur T.

    Irradiation-Enhanced Second-Phase Precipitation in Zr-Fe Nanocrystalline Thin Films D. Kaoumi1 , A with Fe. Heat treatment in the absence of irradiation was observed to cause precipitation of the Zr2Fe in the presence of ion irradiation. Samples were irradiated in-situ at the Intermediate Voltage Electron

  6. GALACTIC EVOLUTION OF Sr, Y, AND Zr: A MULTIPLICITY OF NUCLEOSYNTHETIC PROCESSES Claudia Travaglio,1,2

    E-Print Network [OSTI]

    Cowan, John

    GALACTIC EVOLUTION OF Sr, Y, AND Zr: A MULTIPLICITY OF NUCLEOSYNTHETIC PROCESSES Claudia Travaglio versus Eu, an almost pure r-process element. We present a detailed analysis of a large published database and Sr, Y, Zr all had the same r-process nucleosynthetic origin. We discuss our chemical evolution

  7. Aging behavior and precipitates analysis of the CuCrZrCe alloy Yi Zhang a,b,d,n

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Aging behavior and precipitates analysis of the Cu­Cr­Zr­Ce alloy Yi Zhang a,b,d,n , Alex A October 2015 Keywords: Cu­Cr­Zr­Ce alloy Cold rolling Aging treatment Microstructure Physical properties rolling and aging for 16 h at 300 °C. Under the same aging conditions, without cold rolling, the hardness

  8. RF-driven ion source with a back-streaming electron dump

    DOE Patents [OSTI]

    Kwan, Joe; Ji, Qing

    2014-05-20

    A novel ion source is described having an improved lifetime. The ion source, in one embodiment, is a proton source, including an external RF antenna mounted to an RF window. To prevent backstreaming electrons formed in the beam column from striking the RF window, a back streaming electron dump is provided, which in one embodiment is formed of a cylindrical tube, open at one end to the ion source chamber and capped at its other end by a metal plug. The plug, maintained at the same electrical potential as the source, captures these backstreaming electrons, and thus prevents localized heating of the window, which due to said heating, might otherwise cause window damage.

  9. Development of an L-Band RF Electron Gun for SASE in the Infrared Region

    SciTech Connect (OSTI)

    Kashiwagi, Shigeru; Kato, Ryukou; Isoyama, Goro; Hayano, Hitoshi; Urakawa, Junji

    2010-02-03

    We conduct research on Self-Amplified Spontaneous Emission (SASE) in the infrared region using the 40 MeV, 1.3 GHz L-band linac of Osaka University. The linac equipped with a thermionic electron gun can accelerate a high-intensity single-bunch beam though its normalized emittance is high. In order to advance the research on SASE, we have begun development of an RF gun for the L-band linac in collaboration with KEK. We will report conceptual design of the RF gun and present the status of development of another RF gun for STF at KEK.

  10. Arc Detection and Interlock Module for the PEP II Low Level RF System

    SciTech Connect (OSTI)

    Tighe, R.; /SLAC

    2011-08-31

    A new arc detection and interlock generating module for the SLAC PEP-II low-level RF VXI-based system has been developed. The system is required to turn off the RF drive and high voltage power supply in the event of arcing in the cavity windows, klystron window, or circulator. Infrared photodiodes receive arc signals through radiation resistant optical fibers. Gain and bandwidth are selectable for each channel to allow tailoring response. The module also responds to interlock requests from other modules in the VXI system and communicates with the programmable logic controller (PLC) responsible for much of the low-level RF system's interlock functionality.

  11. RF system considerations for accelerator production of tritium and the transmutation of nuclear waste

    SciTech Connect (OSTI)

    Tallerico, P.J.; Lynch, M.T.

    1993-11-01

    RF driven proton accelerators for the transmutation of nuclear waste (ATW) or for the production of tritium (APT) require unprecedented amounts of CW RF power at UHF frequencies. For both systems, the baseline design is for 246 MW at 700 MHz and 8,5 MW at 350 MHz. The main technical challenges are how to design and build such a large system so that it has excellent reliability, high efficiency, and reasonable capital cost. The issues associated with the selection of the RF amplifier and the sizes of the power supplies are emphasized in this paper.

  12. Laser cooling and sympathetic cooling in a linear quadrupole rf trap 

    E-Print Network [OSTI]

    Ryjkov, Vladimir Leonidovich

    2005-02-17

    cooling method for the studies of large ultra-cold molecular ions in a quadrupole ion trap has been conducted. Molecular dynamics simulations are performed to study the rf heating mecha- nisms in the ion trap. The dependence of rf heating rates on the ion... temperature, trapping parameters, and the number of ions is obtained. New rf heating mechanism affecting ultra-cold ion clouds exposed to laser radiation is described. The saturation spectroscopy setup of the hyperfine spectra of the molecular io- dine has...

  13. Photocatalytic studies of Ho–Zr–O nano-composite with controllable composition and defects

    SciTech Connect (OSTI)

    Du, Weimin, E-mail: duweimin75@gmail.com [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000 (China); Zhao, Guoyan; Chang, Hongxun; Shi, Fei; Zhu, Zhaoqiang [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000 (China); Qian, Xuefeng [School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-09-15

    With the help of sol–gel method assisted by melting salt, a series of Ho–Zr–O nano-composite with controllable composition and defects have been successfully prepared. Characterization results show that the positions, intensity, and width of the X-ray diffraction peaks of the products have a regular variation with the increase of zirconium element which implies the gradual changes of crystal spacing and product size. At the same time, the molar ratios between holmium and zirconium ions are consistent with the chemical formula and both of them are uniformly distributed in products further showing the perfect formation of targeted materials. Optical properties reveal that diversified defect forms of Ho–Zr–O nano-composite lead to the different absorptions of visible light. Photocatalytic experiments demonstrate Zr{sub 0.8}Ho{sub 0.2}O{sub 2??} nano-crystals have excellent visible-light-responsive photocatalytic activities on some familiar dyes (e.g.: methylene blue and Rhodamine B) which results from the special defect structure, better absorption of visible light and larger specific surface area. It follows that Zr{sub 0.8}Ho{sub 0.2}O{sub 2??} nano-crystals are a new kind of visible-light-responsive photocatalysts with better prospects in conversion and utilization of solar energy. Also, the present melting salt assisted route might be generalized to synthesize other AxByOz composite oxide nano-crystals with more complicated structures. - Highlights: • Ho–Zr–O nano-composite with controllable composition and defects has been obtained. • Diversified defect forms of products lead to the different visible light absorption. • Zr{sub 0.8}Ho{sub 0.2}O{sub 2??} nano-crystals have excellent photocatalytic activities.

  14. Band alignment between GaN and ZrO{sub 2} formed by atomic layer deposition

    SciTech Connect (OSTI)

    Ye, Gang; Wang, Hong, E-mail: ewanghong@ntu.edu.sg; Arulkumaran, Subramaniam; Ng, Geok Ing; Li, Yang; Ang, Kian Siong [Novitas, Nanoelectronics Center of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Liu, Zhi Hong [Singapore-MIT Alliance for Research and Technology, 1 CREATE Way, Singapore 138602 (Singapore)

    2014-07-14

    The band alignment between Ga-face GaN and atomic-layer-deposited ZrO{sub 2} was investigated using X-ray photoelectron spectroscopy (XPS). The dependence of Ga 3d and Zr 3d core-level positions on the take-off angles indicated upward band bending at GaN surface and potential gradient in ZrO{sub 2} layer. Based on angle-resolved XPS measurements combined with numerical calculations, valence band discontinuity ?E{sub V} of 1?±?0.2?eV and conduction band discontinuity ?E{sub C} of 1.2?±?0.2?eV at ZrO{sub 2}/GaN interface were determined by taking GaN surface band bending and potential gradient in ZrO{sub 2} layer into account.

  15. Search for spin-orbit-force reduction at {sup 106,108}Zr around r-process path

    SciTech Connect (OSTI)

    Sumikama, T.; Yoshinaga, K. [Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Watanabe, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); and others

    2012-11-12

    Shell gap at the magic number N= 82 is important to reproduce the 2nd peak of r-process abundance. If a spin-orbit force is reduced in a very neutron-rich region, a shell quenching at N= 82 and a new shell closure at N70 are predicted. A shell evolution by the spin-orbit-force reduction can be searched for through the shape evolution of Zr isotopes around an expected double magic nuclei, {sup 110}Zr(Z = 40,N = 70). We performed {beta}-{gamma} and isomer spectroscopy at RIBF to observe low-lying states in {sup 106,108}Zr. The present results indicate a well deformed shape for {sup 106,108}Zr. The drastic reduction of the spin-orbit force most likely does not occur around {sup 110}Zr on an r-process path.

  16. Ab-initio study of high temperature lattice dynamics of BCC zirconium (?-Zr) and uranium (?-U)

    SciTech Connect (OSTI)

    Ghosh, Partha S., E-mail: parthasarathi13@gmail.com; Arya, A., E-mail: parthasarathi13@gmail.com; Dey, G. K., E-mail: parthasarathi13@gmail.com [Materials Science Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2014-04-24

    Using self consistent ab-initio lattice dynamics calculations, we show that bcc structures of Zr and U phases become stable at high temperature by phonon-phonon interactions. The calculated temperature dependent phonon dispersion curve (PDC) of ?-Zr match excellently with experimental PDC. But the calculated PDC for ?-U shows negative phonon frequencies even at solid to liquid transition temperature. We show that this discrepancy is due to an overestimation of instability depth of bcc U phase which is removed by incorporation of spin-orbit coupling in the electronic structure calculations.

  17. Obtaining composite Zr-Al-O coating on the surface of zirconium by microplasma oxidation

    SciTech Connect (OSTI)

    Gubaidulina, Tatiana A. E-mail: ostk@mail2000ru; Kuzmin, Oleg S. E-mail: ostk@mail2000ru; Fedorischva, Marina V. E-mail: kmp1980@mail.ru; Kalashnikov, Mark P. E-mail: kmp1980@mail.ru; Sergeev, Viktor P.

    2014-11-14

    The paper describes the application of the microplasma oxidation for production of Zr-Al-O composition on the surface of zirconium. Certification of a new-type power supply for depositing oxide ceramic coatings by microplasma oxidation was also carried out. The growth rate of Zr-Al-O coating amounted around 0.2 nm/s, which around 10 times exceeds that for depositing similar coatings using the similar equipment. We have studied the change of surface morphology and the chemical composition of the formed ceramic coating by means of EVO 50 scanning electron microscope and X-ray spectral analysis.

  18. Am phases in the matrix of a U–Pu–Zr alloy with Np, Am, and rare-earth elements

    SciTech Connect (OSTI)

    Janney, Dawn E.; Kennedy, J. Rory; Madden, James W.; O’Holleran, Thomas P.

    2015-01-01

    Phases and microstructures in the matrix of an as-cast U-Pu-Zr alloy with 3 wt% Am, 2% Np, and 8% rare-earth elements were characterized by scanning and transmission electron microscopy. The matrix consists primarily of two phases, both of which contain Am: ?-(U, Np, Pu, Am) (~70 at% U, 5% Np, 14% Pu, 1% Am, and 10% Zr) and ?-(U, Np, Pu, Am)Zr2 (~25% U, 2% Np, 10-15% Pu, 1-2% Am, and 55-60 at% Zr). These phases are similar to those in U-Pu-Zr alloys, although the Zr content in ?-(U, Np, Pu, Am) is higher than that in ?-(U, Pu) and the Zr content in ?-(U, Np, Pu, Am)Zr2 is lower than that in ?-UZr2. Nanocrystalline actinide oxides with structures similar to UO2 occurred in some areas, but may have formed by reactions with the atmosphere during sample handling. Planar features consisting of a central zone of ?-(U, Np, Pu, Am) bracketed by zones of ?-(U, Np, Pu, Am)Zr2 bound irregular polygons ranging in size from a few micrometers to a few tens of micrometers across. The rest of the matrix consists of elongated domains of ?-(U, Np, Pu, Am) and ?-(U, Np, Pu, Am)Zr2. Each of these domains is a few tens of nanometers across and a few hundred nanometers long. The domains display strong preferred orientations involving areas a few hundred nanometers to a few micrometers across.

  19. LANGEVIN SIMULATION OF RF CORONA DISCHARGES FOR SPACE HARDWARE M. Alfonseca(1)

    E-Print Network [OSTI]

    Alfonseca, Manuel

    is an electric breakdown process at low neutral gas pressures originated by the progressive outgassing neutral gas pressures lower than ground levels, caused by the progressive outgassing of the entire RF

  20. Understanding and Mitigating the Impact of RF Interference on 802.11 Networks

    E-Print Network [OSTI]

    Abstract We study the impact on 802.11 networks of RF interference from devices such as Zigbee and cordless that includes 2.4GHz cordless phones, Bluetooth headsets, Zigbee Work done while the author was at Intel

  1. PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORY Photonic RF Waveform Synthesis,

    E-Print Network [OSTI]

    Purdue University

    PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORY Photonic RF Waveform, Shijun Xiao Funding from ARO, DARPA, and NSF #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER performance (spectral engineering, dispersion compensation) #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL

  2. Analysis of slice transverse emittance evolutioin in a photocathode RF gun

    E-Print Network [OSTI]

    Huang, Zhirong

    2009-01-01

    evolution at 1 nC for the LCLS gun including the solenoidevolution at 1 nC for the LCLS gun including the solenoidevolution in a photocathode RF gun Zhirong Huang, Yuantao

  3. A CW normal-conductive RF gun for free electron laser and energy recovery linac applications

    E-Print Network [OSTI]

    Baptiste, Kenneth

    2009-01-01

    Todd, State-of-the art electron guns and injector de- signs,7] Summary of working group on guns and injectors, 41st Ad-A CW normal-conductive RF gun for free electron laser and

  4. A high-gradient high-duty-factor Rf photo-cathode electron gun

    E-Print Network [OSTI]

    Rimmer, Robert A.; Hartman, Neal; Lidia, Steven M.; Wang, Shaoheng

    2002-01-01

    approximately 13 MV/m, but in the gun cell the fields couldBeam Radius [mm] End of rf gun Uncompensated Compensated 6preliminary analysis of the gun indicates that the fields in

  5. A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor

    SciTech Connect (OSTI)

    Xiao, Binping; Reece, Charles E.

    2014-02-01

    There is a need to understand the intrinsic limit of radiofrequency (RF) surface impedance that determines the performance of superconducting RF cavities in particle accelerators. Here we present a field-dependent derivation of Mattis-Bardeen theory of the RF surface impedance of BCS superconductors based on the shifted density of states resulting from coherently moving Cooper pairs. Our theoretical prediction of the effective BCS RF surface resistance (Rs) of niobium as a function of peak surface magnetic field amplitude agrees well with recently reported record low loss resonant cavity measurements from JLab and FNAL with carefully, yet differently, prepared niobium material. The surprising reduction in resistance with increasing field is explained to be an intrinsic effect.

  6. Deeply-scaled GaN high electron mobility transistors for RF applications

    E-Print Network [OSTI]

    Lee, Dong Seup

    2014-01-01

    Due to the unique combination of large critical breakdown field and high electron velocity, GaN-based high electron mobility transistors (HEMTs) have great potential for next generation high power RF amplifiers. The ...

  7. Medium Power 352 MHZ solid state pulsed RF amplifiers for the CERN LINAC4 Project

    E-Print Network [OSTI]

    Broere, J; Gómez Martínez, Y; Rossi, M

    2011-01-01

    Economic, modular and highly linear pulsed RF amplifiers have recently been developed to be used for the three buncher cavities in the CERN Linac4. The amplifiers are water-cooled and can provide up to 33 kW pulsed RF Power, 1.5 ms pulse length and 50 Hz repetition rate. Furthermore a 60 kW unit is under construction to provide the required RF Power for the debuncher cavity. The concept is based on 1.2 kW RF power modules using the latest 6th generation LDMOS technology. For integration into the CERN control environment the amplifiers have an internal industrial controller, which will provide easy control and extended diagnostic functions. This paper describes the construction, performance, including linearity, phase stability and EMC compliance tests

  8. Novel RF/Microwave Circuits And Systems for Lab on-Chip/on-Board Chemical Sensors 

    E-Print Network [OSTI]

    Abbas Mohamed Helmy, Ahmed M

    2013-08-02

    Recent research focuses on expanding the use of RF/Microwave circuits and systems to include multi-disciplinary applications. One example is the detection of the dielectric properties of chemicals and bio-chemicals at ...

  9. A CW normal-conductive RF gun for free electron laser and energy recovery linac applications

    E-Print Network [OSTI]

    Baptiste, Kenneth

    2009-01-01

    RF power for 750 kV Peak wall power density Stored energyimpedance, to minimize the wall power density, to reduce theresulting modest power load on the walls is compatible with

  10. A photocathode rf gun design for a mm-wave linac-based FEL

    SciTech Connect (OSTI)

    Nassiri, A.; Berenc, T,; Foster, J.; Waldschmidt, G.; Zhou, J.

    1995-07-01

    In recent years, advances in the rf gun technology have made it possible to produce small beam emittances suitable for short period microundulators which take advantage of the low emittance beam to reduce the wavelength of FELs. At the Advanced Photon Source, we are studying the design of a compact 50-MeV superconducting mm-wave linac-based FEL for the production of short wavelengths ({approximately}300 nm) to carry out FEL demonstration experiments. The electron source considered for the linac is a 30- GHz, 3 1/2-cell {pi}-mode photocathode rf gun. For cold model rf measurements a 15-GHz prototype structure was fabricated. Here we report on the design, numerical modelling and the initial cold-model rf measurement results on the 15-GHz prototype structure.

  11. Design of compact frequency synthesizer for self-calibration in RF circuits 

    E-Print Network [OSTI]

    Park, Sanghoon

    2005-11-01

    A compact frequency synthesizer based on a phase locked loop (PLL) is designed for the self-calibration in RF circuits. The main advantage of the presented frequency synthesizer is that it can be built in a small silicon ...

  12. Transmit field pattern control for high field magnetic resonance imaging with integrated RF current sources 

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01

    The primary design criterion for RF transmit coils for MRI is uniform transverse magnetic (B1) field. Currently, most high frequency transmit coils are designed as periodic, symmetric structures that are resonant at the imaging frequency...

  13. Modeling and Simulation of the Longitudinal Beam Dynamics - RF Station Interaction in the LHC Rings

    SciTech Connect (OSTI)

    Mastorides, T; Rivetta, C.; Fox, J.D.; Winkle, D.Van; /SLAC; Baudrenghien, P.; Tuckmantel, J.; /CERN

    2008-07-07

    A non-linear time-domain simulation has been developed to study the interaction between longitudinal beam dynamics and RF stations in the LHC rings. The motivation for this tool is to determine optimal LLRF configurations, to study system sensitivity on various parameters, and to define the operational and technology limits. It will be also used to study the effect of RF station noise, impedance, and perturbations on the beam life time and longitudinal emittance. It allows the study of alternative LLRF implementations and control algorithms. The insight and experience gained from our PEP-II simulation is important for this work. In this paper we discuss properties of the simulation tool that will be helpful in analyzing the LHC RF system and its initial results. Partial verification of the model with data taken during the LHC RF station commissioning is presented.

  14. Proposal for an RF roadmap towards Ultimate Intensity in the LHC

    E-Print Network [OSTI]

    Baudrenghien, P

    2012-01-01

    The LHC currently operates with 1380 bunches at 50 ns spacing and 1.4 1011 p per bunch (0.35A DC). In this paper the RF operation with ultimate bunch intensity (1.7 1011 p per bunch) and 25 ns spacing (2808 bunches per beam) summing up to 0.86A DC is presented. With the higher beam current, the demanded klystron power will be increased and the longitudinal stability margin reduced. One must also consider the impact of a klystron trip (voltage and power transients in the three turns latency before the beam is actually dumped). In this work a scheme is proposed that can deal with ultimate bunch intensity. Only a minor upgrade of the Low Level RF is necessary: the field set point will be modulated according to the phase shift produced by the transient beam loading, thus minimizing the RF power while keeping the strong feedback for stability and reduction of the RF noise.

  15. Composition-Morphology-Property Relations For Giant Magnetoresistance Multilayers Grown By RF Diode Sputtering

    E-Print Network [OSTI]

    Wadley, Haydn

    University of Virginia, Charlottesville, VA 22903 D. Brownell Nonvolatile Electronics, Inc. Eden Prairie, MN, Inc. (Eden Prairie, MN) using a Randex Model 2400-6J RF diode system. Briefly, the diameter

  16. Tunable Substrate Integrated Waveguide Filters Implemented with PIN Diodes and RF MEMS Switches 

    E-Print Network [OSTI]

    Armendariz, Marcelino

    2012-02-14

    This thesis presents the first fully tunable substrate integrated waveguide (SIW) filter implemented with PIN diodes and RF MEMS switches. The methodology for tuning SIW filters is explained in detail and is used to create three separate designs...

  17. PHYSICAL REVIEW A 90, 012504 (2014) Atomic properties of superheavy elements No, Lr, and Rf

    E-Print Network [OSTI]

    Safronova, Marianna

    2014-01-01

    available. Similar calculations for lighter analogs, ytterbium, lutetium, and hafnium, are used to study are heavier analogs of ytterbium, lutetium, and hafnium. No, Lr, and Rf were studied theoretically

  18. A Wireless Sensing Platform Utilizing Ambient RF Energy Aaron N. Parks 1

    E-Print Network [OSTI]

    Hochberg, Michael

    , such as a battery or supercapacitor, to deal with the blackout period in which its energy source is not available. An RF harvesting node typically need not deal with such a blackout period, and therefore does not need

  19. Highly Parallel Magnetic Resonance Imaging with a Fourth Gradient Channel for Compensation of RF Phase Patterns 

    E-Print Network [OSTI]

    Bosshard, John 1983-

    2012-08-20

    A fourth gradient channel was implemented to provide slice dependent RF coil phase compensation for arrays in dual-sided or "sandwich" configurations. The use of highly parallel arrays for single echo acquisition magnetic resonance imaging allows...

  20. RF sputtering for controlling dihydride and monohydride bond densities in amorphous silicon hydride

    DOE Patents [OSTI]

    Jeffery, F.R.; Shanks, H.R.

    1980-08-26

    A process is described for controlling the dihydride and monohydride bond densities in hydrogenated amorphous silicone produced by reactive rf sputtering of an amorphous silicon target. There is provided a chamber with an amorphous silicon target and a substrate therein with the substrate and the target positioned such that when rf power is applied to the target the substrate is in contact with the sputtering plasma produced thereby. Hydrogen and argon are fed to the chamber and the pressure is reduced in the chamber to a value sufficient to maintain a sputtering plasma therein, and then rf power is applied to the silicon target to provide a power density in the range of from about 7 watts per square inch to about 22 watts per square inch to sputter an amorphous solicone hydride onto the substrate, the dihydride bond density decreasing with an increase in the rf power density. Substantially pure monohydride films may be produced.

  1. Design of RF/IF analog to digital converters for software radio communication receivers 

    E-Print Network [OSTI]

    Thandri, Bharath Kumar

    2007-09-17

    Software radio architecture can support multiple standards by performing analogto- digital (A/D) conversion of the radio frequency (RF) signals and running reconfigurable software programs on the backend digital signal ...

  2. Total ionizing dose effect of ?-ray radiation on the switching characteristics and filament stability of HfOx resistive random access memory

    SciTech Connect (OSTI)

    Fang, Runchen; Yu, Shimeng; Gonzalez Velo, Yago; Chen, Wenhao; Holbert, Keith E.; Kozicki, Michael N.; Barnaby, Hugh

    2014-05-05

    The total ionizing dose (TID) effect of gamma-ray (?-ray) irradiation on HfOx based resistive random access memory was investigated by electrical and material characterizations. The memory states can sustain TID level ?5.2 Mrad (HfO{sub 2}) without significant change in the functionality or the switching characteristics under pulse cycling. However, the stability of the filament is weakened after irradiation as memory states are more vulnerable to flipping under the electrical stress. X-ray photoelectron spectroscopy was performed to ascertain the physical mechanism of the stability degradation, which is attributed to the Hf-O bond breaking by the high-energy ?-ray exposure.

  3. In situ RF/microwave remediation of soil benchtop experiment overview and results

    SciTech Connect (OSTI)

    Regan, A.H.; Palomares, M.E.; Polston, C.; Rees, D.E.; Roybal, W.T.

    1996-06-01

    The authors have developed an in-situ process that combines RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove soil contaminants. They have conducted a number of benchtop experiments involving RF/microwave energy deposition and vapor extraction on controlled contaminated soil samples with successful removal of the DNAPL contaminants. This paper will describe the experiments performed and present results.

  4. Sensitivity of Niobium Superconducting RF Cavities to Magnetic Field

    E-Print Network [OSTI]

    Gonnella, Dan

    2015-01-01

    Future particle accelerators such as the the SLAC "Linac Coherent Light Source-II" (LCLS-II) and the proposed Cornell Energy Recovery Linac (ERL) require hundreds of superconducting RF (SRF) cavities operating in continuous wave (CW) mode. In order to achieve economic feasibility of projects such as these, the cavities must achieve a very high intrinsic quality factor (Q0). In order to reach these high Q0's in the case of LCLS-II, nitrogen-doping has been proposed as a cavity preparation technique. When dealing with Q0's greater than 1x10^10, the effects of ambient magnetic field on Q0 become significant. Here we show that the sensitivity that a cavity has to ambient magnetic field is highly dependent on the cavity preparation. Specifically, standard electropolished and 120C baked cavities show a sensitivity of ~0.8 and ~0.6 nOhm/mG trapped, respectively, while nitrogen-doped cavities show a sensitivity of ~2 to 5 nOhm/mG trapped. Less doping results in weaker sensitivity. This difference in sensitivities is ...

  5. Klystron Cluster Scheme for ILC High Power RF Distribution

    SciTech Connect (OSTI)

    Nantista, Christopher; Adolphsen, Chris; /SLAC

    2009-07-06

    We present a concept for powering the main linacs of the International Linear Collider (ILC) by delivering high power RF from the surface via overmoded, low-loss waveguides at widely spaced intervals. The baseline design employs a two-tunnel layout, with klystrons and modulators evenly distributed along a service tunnel running parallel to the accelerator tunnel. This new idea eliminates the need for the service tunnel. It also brings most of the warm heat load to the surface, dramatically reducing the tunnel water cooling and HVAC requirements. In the envisioned configuration, groups of 70 klystrons and modulators are clustered in surface buildings every 2.5 km. Their outputs are combined into two half-meter diameter circular TE{sub 01} mode evacuated waveguides. These are directed via special bends through a deep shaft and along the tunnel, one upstream and one downstream. Each feeds approximately 1.25 km of linac with power tapped off in 10 MW portions at 38 m intervals. The power is extracted through a novel coaxial tap-off (CTO), after which the local distribution is as it would be from a klystron. The tap-off design is also employed in reverse for the initial combining.

  6. Automatic Pole and Q-Value Extraction for RF Structures

    SciTech Connect (OSTI)

    C. Potratz, H.-W. Glock, U. van Rienen, F. Marhauser

    2011-09-01

    The experimental characterization of RF structures like accelerating cavities often demands for measuring resonant frequencies of Eigenmodes and corresponding (loaded) Q-values over a wide spectral range. A common procedure to determine the Q-values is the -3dB method, which works well for isolated poles, but may not be applicable directly in case of multiple poles residing in close proximity (e.g. for adjacent transverse modes differing by polarization). Although alternative methods may be used in such cases, this often comes at the expense of inherent systematic errors. We have developed an automation algorithm, which not only speeds up the measurement time significantly, but is also able to extract Eigenfrequencies and Q-values both for well isolated and overlapping poles. At the same time the measurement accuracy may be improved as a major benefit. To utilize this procedure merely complex scattering parameters have to be recorded for the spectral range of interest. In this paper we present the proposed algorithm applied to experimental data recorded for superconducting higher-order-mode damped multi-cell cavities as an application of high importance.

  7. Phase Noise of the Radio Frequency (RF) Beatnote Generated by a Dual-Frequency VECSEL

    E-Print Network [OSTI]

    Syamsundar De; Abdelkrim El Amili; Ihsan Fsaifes; Grégoire Pillet; Ghaya Baili; Fabienne Goldfarb; Mehdi Alouini; Isabelle Sagnes; Fabien Bretenaker

    2013-11-13

    We analyze, both theoretically and experimentally, the phase noise of the radio frequency (RF) beatnote generated by optical mixing of two orthogonally polarized modes in an optically pumped dual-frequency Vertical External Cavity Surface Emitting Laser (VECSEL). The characteristics of the RF phase noise within the frequency range of 10 kHz - 50 MHz are investigated for three different nonlinear coupling strengths between the two lasing modes. In the theoretical model, we consider two different physical mechanisms responsible for the RF phase noise. In the low frequency domain (typically below 500 kHz), the dominant contribution to the RF phase noise is shown to come from the thermal fluctuations of the semicondutor active medium induced by pump intensity fluctuations. However, in the higher frequency domain (typically above 500 kHz), the main source of RF phase noise is shown to be the pump intensity fluctuations which are transfered to the intensity noises of the two lasing modes and then to the phase noise via the large Henry factor of the semiconductor gain medium. For this latter mechanism, the nonlinear coupling strength between the two lasing modes is shown to play an important role in the value of the RF phase noise. All experimental results are shown to be in good agreement with theory.

  8. Transmission electron microscopy examination of oxide layers formed on Zr alloys

    E-Print Network [OSTI]

    Motta, Arthur T.

    Transmission electron microscopy examination of oxide layers formed on Zr alloys Aylin Yilmazbayhan, United States Received 14 July 2005; accepted 31 October 2005 Abstract A transmission electron microscopy. In this work, cross-sectional transmission electron microscopy was used to determine the morphology

  9. Phase Stability and Thermodynamic Assessment of the Np-Zr system 

    E-Print Network [OSTI]

    Bajaj, Saurabh

    2012-02-14

    of minor actinides and fission products on phase stability. Within this framework, we present a study on phase equilibria in the binary Np-Zr alloy system on which little work has been published. To resolve the contradictory reports on the ordering...

  10. Microfluxgate sensor with amorphous cobalt (Co-Nb-Zr) soft magnetic core for electronic compass

    SciTech Connect (OSTI)

    Na, Kyoung-Won; Yuan, Jingli; Ji, Joon-Ho; Choi, Sang-On [Nano Fabrication Center, Samsung Advanced Institute of Technology (SAIT) (Korea, Republic of); MEMS Laboratory, Samsung Advanced Institute of Technology (SAIT) (Korea, Republic of)

    2006-04-15

    A silicon based microfluxgate sensor with a cobalt based amorphous soft magnetic core for electronic compass is presented in this paper. A sputtered Co{sub 85}Nb{sub 12}Zr{sub 3} magnetic core having a rectangular ring shape is combined with microcopper solenoid coils for excitation and pickup, which were wound alternately around the core to increase the number of coil turns. The Co{sub 85}Nb{sub 12}Zr{sub 3} as a core material is adopted for improving properties of the magnetic core and easy integration with micromachining processes to achieve a small size of the sensor. The sputtered Co{sub 85}Nb{sub 12}Zr{sub 3} showed dc effective permeability of {approx}10 000 and an extremely low coercivity of {approx}0.03 Oe with the thickness of 1 {mu}m. The Co{sub 85}Nb{sub 12}Zr{sub 3} as a thin film core with high permeability and low coercivity was easily saturated by a low excitation magnetic field, enhancing the sensitivity and linearity of the microfluxgate sensor. Finally, the sensor showed excellent linearity response over the range of -300 to 300 {mu}T with sensitivity of 60 V/T at the excitation condition of 3.0 V{sub p-p} and 5.0 MHz square wave form. The sensor size excluding pad region is about 0.55x1.4 mm{sup 2}.

  11. Effect of Niobium on the Defect Chemistry and Oxidation Kinetics of Tetragonal ZrO2

    E-Print Network [OSTI]

    Yildiz, Bilge

    of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge transport limits the oxidation kinetics. 1. INTRODUCTION Zirconia (ZrO2) is among the most important metal-6 Furthermore, zirconia is used in biomedical hip implants7 and dental restorations8 and recently

  12. RF Design and Operating Results for a New 201.25 MHz RF Power Amplifier for LANSCE

    SciTech Connect (OSTI)

    Lyles, John T. [Los Alamos National Laboratory; Baca, David M. [Los Alamos National Laboratory; Bratton, Ray E. [Los Alamos National Laboratory; Brennan, Nicholas W. [Los Alamos National Laboratory; Bultman, Nathan K. [Los Alamos National Laboratory; Chen, Zukun [Los Alamos National Laboratory; Davis, Jerry L. [Los Alamos National Laboratory; Naranjo, Angela C. [Los Alamos National Laboratory; Rees, Daniel E. [Los Alamos National Laboratory; Sandoval, Gilbert M. Jr. [Los Alamos National Laboratory; Summers, Richard D. [Los Alamos National Laboratory

    2011-01-01

    A prototype VHF RF Final Power Amplifier (FPA) for Los Alamos Neutron Science Center (LANSCE) has been designed, fabricated, and tested. The cavity amplifier has met the goals of generating 2.5 MW peak and 260 kW of average power, at an elevation of 2.1 km. It was designed to use a Thales TH628 Diacrode{sup R}, a state-of-art tetrode power tube that is double-ended, providing roughly twice the power of a conventional tetrode. The amplifier is designed with tunable input and output transmission line cavity circuits, a grid decoupling circuit, an adjustable output coupler, TE mode suppressors, blocking, bypassing and decoupling capacitors, and a cooling system. The tube is connected in a full wavelength output circuit, with the lower main tuner situated 3/4{lambda} from the central electron beam region in the tube and the upper slave tuner 1/4{lambda} from the same point. We summarize the design processes and features of the FPA along with significant test results. A pair of production amplifiers are planned to be power-combined and installed at the LANSCE DTL to return operation to full beam duty factor.

  13. Effect of the oxide layer on current-induced spin-orbit torques in Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} structures

    SciTech Connect (OSTI)

    Akyol, Mustafa; Alzate, Juan G.; Yu, Guoqiang; Upadhyaya, Pramey; Wong, Kin L.; Khalili Amiri, Pedram; Wang, Kang L.; Ekicibil, Ahmet

    2015-01-19

    We study the effect of the oxide layer on the current-induced spin-orbit torques (SOTs) in perpendicularly magnetized Hf|CoFeB|MgO (MgO-capped) or Hf|CoFeB|TaO{sub x} (TaO{sub x}-capped) structures. The effective fields corresponding to both the field-like and damping-like current-induced SOTs are characterized using electric transport measurements. Both torques are found to be significantly stronger in MgO-capped structures than those in TaO{sub x}-capped structures. The difference in field-like and damping-like SOTs in the different structures may be attributed to the different Rashba-like Hamiltonian, arising from the difference in the electric potential profiles across the oxide|ferromagnet interfaces in the two cases, as well as possible structural and oxidation differences in the underlying CoFeB and Hf layers. Our results show that the oxide layer in heavy-metal|ferromagnet|oxide trilayer structures has a very significant effect on the generated SOTs for manipulation of ferromagnetic layers. These findings could potentially be used to engineer SOT devices with enhanced current-induced switching efficiency.

  14. Structural and microstructural changes in monoclinic ZrO{sub 2} during the ball-milling with stainless steel assembly

    SciTech Connect (OSTI)

    Stefanic, G. . E-mail: stefanic@irb.hr; Music, S.; Gajovic, A.

    2006-04-13

    High-energy ball-milling of monoclinic ZrO{sub 2} was performed in air using the planetary ball mill with a stainless steel milling assembly. Structural and microstructural changes during the ball-milling were monitored using X-ray powder diffraction, Raman spectroscopy, Moessbauer spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray spectrometry. The results of line broadening analysis indicated a decrease in the crystallite size and an increase in the microstrains with the ball-milling time increased up to {approx}150 min. The results of quantitative phase analysis indicated the presence of a very small amount of tetragonal ZrO{sub 2} phase in this early stage of ball-milling. The onset of m-ZrO{sub 2} {sup {yields}} t-ZrO{sub 2} transition occurred between 10 and 15 h of ball-milling, which resulted in a complete transition after 20 h of ball-milling. Further ball-milling caused a decrease of the t-ZrO{sub 2} lattice parameters followed by a probable transition into c-ZrO{sub 2}. It was concluded that the stabilization of t- and c-ZrO{sub 2} polymorphs at RT can be attributed to the incorporation of aliovalent cations (Fe{sup 2+}, Fe{sup 3+} and Cr{sup 3+}) introduced into the sample due to the wear and oxidation of the milling media.

  15. Morphology and chemical termination of HF-etched Si{sub 3}N{sub 4} surfaces

    SciTech Connect (OSTI)

    Liu, Li-Hong; Debenedetti, William J. I.; Peixoto, Tatiana; Gokalp, Sumeyra; Shafiq, Natis; Veyan, Jean-François; Chabal, Yves J.; Michalak, David J.; Hourani, Rami

    2014-12-29

    Several reports on the chemical termination of silicon nitride films after HF etching, an important process in the microelectronics industry, are inconsistent claiming N-H{sub x}, Si-H, or fluorine termination. An investigation combining infrared and x-ray photoelectron spectroscopies with atomic force and scanning electron microscopy imaging reveals that under some processing conditions, salt microcrystals are formed and stabilized on the surface, resulting from products of Si{sub 3}N{sub 4} etching. Rinsing in deionized water immediately after HF etching for at least 30?s avoids such deposition and yields a smooth surface without evidence of Si-H termination. Instead, fluorine and oxygen are found to terminate a sizeable fraction of the surface in the form of Si-F and possibly Si-OH bonds. The relatively unique fluorine termination is remarkably stable in both air and water and could lead to further chemical functionalization pathways.

  16. Composition and grain size effects on the structural and mechanical properties of CuZr nanoglasses

    SciTech Connect (OSTI)

    Adibi, Sara [Institute of High Performance Computing, A*STAR, 138632 Singapore (Singapore); Mechanical Engineering Department, National University of Singapore, 117576 Singapore (Singapore); Branicio, Paulo S., E-mail: branicio@ihpc.a-star.edu.sg; Zhang, Yong-Wei [Institute of High Performance Computing, A*STAR, 138632 Singapore (Singapore); Joshi, Shailendra P., E-mail: Shailendra@nus.edu.sg [Mechanical Engineering Department, National University of Singapore, 117576 Singapore (Singapore)

    2014-07-28

    Nanoglasses (NGs), metallic glasses (MGs) with a nanoscale grain structure, have the potential to considerably increase the ductility of traditional MGs while retaining their outstanding mechanical properties. We investigated the effects of composition on the structural and mechanical properties of CuZr NG films with grain sizes between 3 to 15?nm using molecular dynamics simulations. Results indicate a transition from localized shear banding to homogeneous superplastic flow with decreasing grain size, although the critical average grain size depends on composition: 5?nm for Cu{sub 36}Zr{sub 64} and 3?nm for Cu{sub 64}Zr{sub 36}. The flow stress of the superplastic NG at different compositions follows the trend of the yield stress of the parent MG, i.e., Cu{sub 36}Zr{sub 64} yield/flow stress: 2.54?GPa/1.29?GPa and Cu{sub 64}Zr{sub 36} yield/flow stress: 3.57?GPa /1.58?GPa. Structural analysis indicates that the differences in mechanical behavior as a function of composition are rooted at the distinct statistics of prominent atomic Voronoi polyhedra. The mechanical behavior of NGs is also affected by the grain boundary thickness and the fraction of atoms at interfaces for a given average grain size. The results suggest that the composition dependence of the mechanical behavior of NGs follows that of their parent MGs, e.g., a stronger MG will generate a stronger NG, while the intrinsic tendency for homogeneous deformation occurring at small grain size is not affected by composition.

  17. Glass formation in binary and ternary Zr based Fe and Ni bearing alloys

    SciTech Connect (OSTI)

    Savalia, R.T.; Tewari, R.; Banerjee, S.; Dey, G.K.

    1996-01-01

    Rapid solidification of the Zr{sub 76}Fe{sub 24-x}Ni{sub x} alloys (x - 0, 4, 8, 12, 16, 20 and 24) by melt spinning under different conditions has yielded fully amorphous as well as partially crystalline ribbons. The partially crystalline ribbons have been found to contain crystal aggregates comprising a core of the {beta}-Zr phase surrounded by peripheral crystals of the Zr{sub 3}(Fe,Ni) phase in alloys with x < 12. In alloys containing larger amount of Ni (x {ge} 12), both Zr{sub 2}Ni and Zr{sub 3}(Fe,Ni) crystals have been found to be present in the periphery. The nucleation of the core crystals and the peripheral crystals in the undercooled melt has been examined by considering transient and steady state homogeneous and heterogeneous nucleation. The transient nucleation time and the steady state nucleation rate of crystals have been evaluated. For this purpose, use has been made of molar free energy difference {Delta}G{sub c} between the liquid and the crystalline phases determined from experimentally evaluated quantities. The growth of the crystals in the undercooled melt has been examined taking into account recalescence and heat removal during melt spinning. The glass forming ability of the alloys has been evaluated on the basis of the avoidance of crystallization approach. A comparison has been made between the microstructures of the splat cooled and the melt spun alloys in order to understand the process of solidification and the nature of phase transformation during post solidification cooling.

  18. Calculations of the cross sections for the neutron acceleration, slowing down, and capture by the isomer "OmHf

    E-Print Network [OSTI]

    Shlyakhter, Ilya

    Calculations of the cross sections for the neutron acceleration, slowing down, and capture for the isomer lsomHf in the energy range of the incoming neutron from 1keV to 5 MeV. Below 0.7 MeV the energy transferred to the neutron in the collision is positive on the average, i.e., the isomer is acting

  19. Report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012)

    E-Print Network [OSTI]

    Alain Blondel; Alex Chao; Weiren Chou; Jie Gao; Daniel Schulte; Kaoru Yokoya

    2013-02-15

    This paper is a summary report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012). It discusses four types of accelerators as possible candidates for a Higgs factory: linear e+e- colliders, circular e+e- colliders, muon collider and photon colliders. The comparison includes: physics reach, performance (energy and luminosity), upgrade potential, technology maturity and readiness, and technical challenges requiring further R&D.

  20. Structure and properties of nanocrystalline ZrN{sub x}O{sub y} thin films: Effect of the oxygen content and film thickness

    SciTech Connect (OSTI)

    Lan, Kuan-Che; Hunag, Jia-Hong; Ai, Chi-Fong; Yu, Ge-Ping [Department of Engineering and System Science, National Tsing Hua University, 101 Kuang Fu Rd., Sec. 2, Hsinchu, 300 Taiwan (China); Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan, 325 Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, 101 Kuang Fu Rd., Sec. 2, Hsinchu, 300 Taiwan (China) and Institute of Nuclear Engineering and Science, 101 Kuang Fu Rd., Sec. 2, Hsinchu, 300 Taiwan (China)

    2011-05-15

    The main objective of this study was to investigate the structure and properties of ZrN{sub x}O{sub y} thin films associated with oxygen content and film thickness. ZrN{sub x}O{sub y} thin films were deposited using hollow cathode discharge ion plating on Si (100) substrate. The thickness of ZrN{sub x}O{sub y} films increased with increasing oxygen flow rate, ranging from 143 to 894 nm. Phase separation from ZrN{sub x}O{sub y} to ZrN and monoclinic ZrO{sub 2} (m-ZrO{sub 2}) was observed by x-ray diffraction (XRD). The electrical and mechanical properties were influenced by the film thickness and the amount of separated phase, m-ZrO{sub 2}. ZrN{sub x}O{sub y} thin films with smaller thickness or deposited at higher O{sub 2} flow rate were found to have higher electrical resistivity. Hardness of the ZrN{sub x}O{sub y} thin films increased with increasing thickness, which could be related to microstructure change of the thin films. Residual stress of the ZrN phase in the ZrN{sub x}O{sub y} thin films, measured using the modified sin{sup 2} {psi} XRD method, decreased with increasing oxygen flow rate. The thickness dependence of the residual stress in ZrN was different with different oxygen flow rates. The average residual stress of the ZrN{sub x}O{sub y} thin films also decreased with increasing oxygen flow rate and the stress did not showed significant dependence on the film thickness.

  1. Effect of Zr on microstructures and mechanical properties of an Al-Mg-Si-Cu-Cr alloy prepared by low frequency electromagnetic casting

    SciTech Connect (OSTI)

    Meng, Yi, E-mail: yimonmy@sina.com; Cui, Jianzhong; Zhao, Zhihao; He, Lizi

    2014-06-01

    The Al-1.6Mg-1.2Si-1.1Cu-0.15Cr (all in wt. %) alloys with and without Zr addition prepared by low frequency electromagnetic casting process were investigated by using the optical microscope, scanning electron microscope and transmission electron microscope equipped with energy dispersive analytical X-ray. The effects of Al{sub 3}Zr phases on the microstructures and mechanical properties during solidification, homogenization, hot extrusion and solid solution were studied. The results show that Al{sub 3}Zr phases reduce the grain size by ? 29% and promote the formation of an equiaxed grain structure during solidification. Numerous spherical Al{sub 3}Zr dispersoids with 35–60 nm in diameters precipitate during homogenization, and these fine dispersoids change little during subsequent hot extrusion and solid solution. Adding 0.15 wt. % Zr results in no recrystallization after hot extrusion and partial recrystallization after solid solution, while the recrystallized grain size is 400–550 ?m in extrusion direction in the Zr-free alloy. In addition, adding 0.15 wt. % Zr can obviously promote Q? phase precipitation, while the ?? phases are predominant in the alloy without Zr. Adding 0.15 wt. % Zr, the ultimate tensile strength of the T6 treated alloy increases by 45 MPa, while the elongation remains about 16.7%. - Highlights: • Minor Zr can refine as-cast grains of the LFEC Al-Mg-Si-Cu-Cr alloy. • L1{sub 2} Al{sub 3}Zr phases with 35–60 nm in diameter precipitate during homogenization. • L1{sub 2} and DO{sub 22} Al{sub 3}Zr phases result in partial recrystallization after solid solution. • Minor Zr can promote the precipitation of Q? phases. • Mechanical properties of Al-Mg-Si-Cu-Cr-Zr alloy are higher than those of AA7005.

  2. N-body simulations of oligarchic growth of Mars: Implications for Hf-W chronology

    E-Print Network [OSTI]

    Morishima, Ryuji; Samuel, Henri

    2013-01-01

    Dauphas and Pourmand (2011) [Nature 473, 489--492] estimated the accretion timescale of Mars to be 1.8 $^{+0.9}_{-1.0}$ Myr from the W isotopes of martian meteorites. This timescale was derived assuming perfect metal-silicate equilibration between the impactor and the target's mantle. However, in the case of a small impactor most likely only a fraction of the target's mantle is involved in the equilibration, while only a small part of the impactor's core equilibrates in the case of a giant impact. We examined the effects of imperfect equilibration using results of high-resolution $N$-body simulations for the oligarchic growth stage. These effects were found to be small as long as a planetary embryo has a deep liquid magma ocean during its accretion. The effect due to partial involvement of the target's mantle in equilibration is small due to the low metal-silicate partition coefficient for W suggested from the low Hf/W ratio of the martian mantle. The effect due to partial involvement of the impactor's core i...

  3. Temperature dependent structural, optical and hydrophobic properties of sputtered deposited HfO{sub 2} films

    SciTech Connect (OSTI)

    Dave, V. [Department of Electrical Engineering, IIT Roorkee (India); Institute Instrumentation Centre, IIT Roorkee (India); Dubey, P.; Chandra, R. [Institute Instrumentation Centre, IIT Roorkee (India); Gupta, H. O. [Department of Electrical Engineering, IIT Roorkee (India)

    2014-01-28

    Hafnium oxide being high-k dielectric has been successfully utilized in electronic and optical applications. Being thermodynamically stable and having good mechanical strength, it can be used as a protective coating for outdoor HV insulators which are suffering from surface flashover problem due to contamination. In this paper, we are investigating the effect of substrate temperature on structural, optical and hydrophobic properties of hafnium oxide coating deposited over glass insulators by DC magnetron sputtering. X-ray diffraction is applied to determine the crystalline phase and crystallite size of the film. The morphology of the samples is examined using atomic force microscopy. The optical properties are studied using UV-vis-NIR spectrophotometer. The wettability of the film is investigated using contact angle meter. The thickness is measured using surface profilometer and verified through optical data. The relationship between substrate temperature with grain size, roughness, refractive index, and hydrophobicity is manifested. The maximum contact angle for HfO{sub 2} film was found to be 106° at 400°C.

  4. Experiments and theory on parametric instabilities excited in HF heating experiments at HAARP

    SciTech Connect (OSTI)

    Kuo, Spencer; Snyder, Arnold; Lee, M. C.

    2014-06-15

    Parametric instabilities excited by O-mode HF heater and the induced ionospheric modification were explored via HAARP digisonde operated in a fast mode. The impact of excited Langmuir waves and upper hybrid waves on the ionosphere are manifested by bumps in the virtual spread, which expand the ionogram echoes upward as much as 140?km and the downward range spread of the sounding echoes, which exceeds 50?km over a significant frequency range. The theory of parametric instabilities is presented. The theory identifies the ionogram bump located between the 3.2?MHz heater frequency and the upper hybrid resonance frequency and the bump below the upper hybrid resonance frequency to be associated with the Langmuir and upper hybrid instabilities, respectively. The Langmuir bump is located close to the upper hybrid resonance frequency, rather than to the heater frequency, consistent with the theory. Each bump in the virtual height spread of the ionogram is similar to the cusp occurring in daytime ionograms at the E-F2 layer transition, indicating that there is a small ledge in the density profile similar to E-F2 layer transitions. The experimental results also show that the strong impact of the upper hybrid instability on the ionosphere can suppress the Langmuir instability.

  5. Features of the band structure and conduction mechanisms in the n-HfNiSn semiconductor heavily doped with Ru

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Stadnyk, Yu. V.; Korzh, R. O.; Krayovskyy, V. Ya.; Horyn, A. M.

    2014-12-15

    The crystal and electronic structure and energy and kinetic properties of the n-HfNiSn semiconductor heavily doped with a Ru acceptor impurity are investigated in the temperature and Ru concentration ranges T = 80–400 K and N{sub A}{sup Ru} ? 9.5 × 10{sup 19}?5.7 × 10{sup 20} cm{sup ?3} (x = 0–0.03), respectively. The mechanism of structural-defect generation is established, which changes the band gap and degree of compensation of the semiconductor and consists in the simultaneous concentration reduction and elimination of donor structural defects by means of the displacement of ?1% of Ni atoms from the Hf (4a) positions, the generation of acceptor structural defects upon the substitution of Ru atoms for Ni atoms in the 4c positions, and the generation of donor defects in the form of vacancies in the Sn (4b) positions. The calculated electronic structure of HfNi{sub 1?x}Ru{sub x}Sn is consistent with the experiment. The results obtained are discussed within the Shklovsky-Efros model for a heavily doped and compensated semiconductor.

  6. Effects of Support Composition and Pretreatment Conditions on the Structure of Vanadia Dispersed on SiO2, Al2O3, TiO2, ZrO2, and HfO2

    E-Print Network [OSTI]

    Iglesia, Enrique

    , including the selective reduction of NOx with ammonia and the oxidative dehydroge- nation of alkanes.1-visible) were utilized to monitor the effect of adsorbed water, calcination temperature, and reduction in H2 a phase transition from tetragonal to monoclinic. H2 reduction produced limited changes in the structure

  7. Characteristics of a RF-Driven Ion Source for a Neutron Generator Used For Associated Particle Imaging

    E-Print Network [OSTI]

    Wu, Ying

    2010-01-01

    compact RF-driven neutron generator Los Alamos NationalSource for a Neutron Generator Used For Associated Particleprototype compact neutron generator for associated particle

  8. Stellar 30-keV neutron capture in 94,96Zr and the 90Zr(gamma,n)89Zr photonuclear reaction with a high-power liquid-lithium target

    E-Print Network [OSTI]

    Tessler, M; Arenshtam, A; Feinberg, G; Friedman, M; Halfon, S; Kijel, D; Weissman, L; Aviv, O; Berkovits, D; Eisen, Y; Eliyahu, I; Haquin, G; Kreisel, A; Mardor, I; Shimel, G; Shor, A; Silverman, I; Yungrais, Z

    2015-01-01

    A high-power Liquid-Lithium Target (LiLiT) was used for the first time for neutron production via the thick-target 7Li(p,n)7Be reaction and quantitative determination of neutron capture cross sections. Bombarded with a 1-2 mA proton beam at 1.92 MeV from the Soreq Applied Research Accelerator Facility (SARAF), the setup yields a 30-keV quasi-Maxwellian neutron spectrum with an intensity of 3-5e10 n/s, more than one order of magnitude larger than present near-threshold 7Li(p,n) neutron sources. The setup was used here to determine the 30-keV Maxwellian averaged cross section (MACS) of 94Zr and 96Zr as 28.0+-0.6 mb and 12.4+-0.5 mb respectively, based on activation measurements. The precision of the cross section determinations results both from the high neutron yield and from detailed simulations of the entire experimental setup. We plan to extend our experimental studies to low-abundance and radioactive targets. In addition, we show here that the setup yields intense high-energy (17.6 and 14.6 MeV) prompt cap...

  9. Stabilizing effect of a double-harmonic RF system in the CERN PS

    SciTech Connect (OSTI)

    Bhat, C.; Caspers, F.; Damerau, H.; Hancock, S.; Mahner, E.; Zimmermann, F.; /CERN

    2009-04-01

    Motivated by the discussions on scenarios for LHC upgrades, beam studies on the stability of flat bunches in a double-harmonic RF system have been conducted in the CERN Proton Synchrotron (PS). Injecting nearly nominal LHC beam intensity per cycle, 18 bunches are accelerated on harmonic h = 21 to 26GeV with the 10MHz RF system. On the flat-top, all bunches are then transformed to flat bunches by adiabatically adding RF voltage at h = 42 from a 20 MHz cavity in anti-phase to the h = 21 system. The voltage ratio V (h42)/V (h21) of about 0.5 was set according to simulations. For the next 140 ms, longitudinal profiles show stable bunches in the double-harmonic RF bucket until extraction. Without the second harmonic component, coupled-bunch oscillations are observed. The flatness of the bunches along the batch is analyzed as a measure of the relative phase error between the RF systems due to beam loading. The results of beam dynamics simulations and their comparison with the measured data are presented.

  10. Simulation of RF Cavity Dark Current in Presence of Helical Magnetic Field

    SciTech Connect (OSTI)

    Romanov, Gennady; Kashikhin, Vladimir; /Unlisted

    2010-09-01

    In order to produce muon beam of high enough quality to be used for a Muon Collider, its large phase space must be cooled several orders of magnitude. This task can be accomplished by ionization cooling. Ionization cooling consists of passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF cavities within a multi-Tesla solenoidal focusing channel. But first high power tests of RF cavity with beryllium windows in solenoidal magnetic field showed a dramatic drop in accelerating gradient due to RF breakdowns. It has been concluded that external magnetic fields parallel to RF electric field significantly modifies the performance of RF cavities. However, magnetic field in Helical Cooling Channel has a strong dipole component in addition to solenoidal one. The dipole component essentially changes electron motion in a cavity compare to pure solenoidal case, making dark current less focused at field emission sites. The simulation of dark current dynamic in HCC performed with CST Studio Suit is presented in this paper.

  11. Multipole and field uniformity tailoring of a 750 MHz rf dipole

    SciTech Connect (OSTI)

    Delayen, Jean R. [JLAB, Old Dominion University; Castillo, Alejandro [JLAB, Old Dominion University

    2014-12-01

    In recent years great interest has been shown in developing rf structures for beam separation, correction of geometrical degradation on luminosity, and diagnostic applications in both lepton and hadron machines. The rf dipole being a very promising one among all of them. The rf dipole has been tested and proven to have attractive properties that include high shunt impedance, low and balance surface fields, absence of lower order modes and far-spaced higher order modes that simplify their damping scheme. As well as to be a compact and versatile design in a considerable range of frequencies, its fairly simple geometry dependency is suitable both for fabrication and surface treatment. The rf dipole geometry can also be optimized for lowering multipacting risk and multipole tailoring to meet machine specific field uniformity tolerances. In the present work a survey of field uniformities, and multipole contents for a set of 750 MHz rf dipole designs is presented as both a qualitative and quantitative analysis of the inherent flexibility of the structure and its limitations.

  12. Simulation of RF Cavity Dark Current In Presence of Helical Magnetic Field

    SciTech Connect (OSTI)

    Romanov, Gennady; Kashikhin, Vladimir; /Fermilab

    2012-05-01

    In order to produce muon beam of high enough quality to be used for a Muon Collider, its large phase space must be cooled several orders of magnitude. This task can be accomplished by ionization cooling. Ionization cooling consists of passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF cavities within a multi-Tesla solenoidal focusing channel. But first high power tests of RF cavity with beryllium windows in solenoidal magnetic field showed a dramatic drop in accelerating gradient due to RF breakdowns. It has been concluded that external magnetic fields parallel to RF electric field significantly modifies the performance of RF cavities. However, magnetic field in Helical Cooling Channel has a strong dipole component in addition to solenoidal one. The dipole component essentially changes electron motion in a cavity compare to pure solenoidal case, making dark current less focused at field emission sites. The simulation of dark current dynamic in HCC performed with CST Studio Suit is presented in this paper.

  13. Modeling the ion density distribution in collisional cooling RF multipole ion guides

    SciTech Connect (OSTI)

    Tolmachev, Aleksey V.; Udseth, Harold R.; Smith, Richard D.

    2003-01-01

    Collisional cooling radio frequency (RF) multipoles are widely used in mass spectrometry, as ion guides and two-dimensional (2D) ion traps. Understanding the behavior of ions in these devices is important in choosing a multipole configuration. We have developed a computer model based on ion trajectory calculations in the RF multipole electric field, taking into account ion-ion and ion-neutral interactions. The two-dimensional model for idealized infinite RF multipoles gives accurate description of the ion density distribution. We consider first a basic case of a single m/z ion cloud in the 2D RF quadrupole after equilibrium is reached. Approximate theoretical relationships for the ion cloud configuration in the 2D ion trap are tested based on simulations results. Next we proceed with a case of an ion cloud consisting of several different m/z ion species. The ion relaxation dynamics and the process of establishing the stratified ion density distribution are followed. Simulations reveal a different relaxation dynamics for the axial and radial ion kinetic energy components. The kinetic energy relaxation rate is dependent on ion population and bath gas pressure. The equilibrium distribution agrees well with the ion stratification theory, as demonstrated by simulations for RF quadrupole and octupole 2D ion traps.

  14. Hardness variation and cyclic crystalline-amorphous phase transformation in CuZr alloy during ball milling

    E-Print Network [OSTI]

    Schoen, David Taylor

    2005-01-01

    The hardness and percent crystallinity of Cu33Zr67 powder samples are measured through several cycles of a cyclic phase transformation during ball milling. Each are found to cycle with a period of approximately 320 minutes. ...

  15. Charge-trapping characteristics of fluorinated thin ZrO{sub 2} film for nonvolatile memory applications

    SciTech Connect (OSTI)

    Huang, X. D., E-mail: eexdhuang@gmail.com, E-mail: laip@eee.hku.hk [Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096 (China); Shi, R. P.; Lai, P. T., E-mail: eexdhuang@gmail.com, E-mail: laip@eee.hku.hk [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2014-04-21

    The effects of fluorine treatment on the charge-trapping characteristics of thin ZrO{sub 2} film are investigated by physical and electrical characterization techniques. The formation of silicate interlayer at the ZrO{sub 2}/SiO{sub 2} interface is effectively suppressed by fluorine passivation. However, excessive fluorine diffusion into the Si substrate deteriorates the quality of the SiO{sub 2}/Si interface. Compared with the ZrO{sub 2}-based memory devices with no or excessive fluorine treatment, the one with suitable fluorine-treatment time shows higher operating speed and better retention due to less resistance of built-in electric field (formed by trapped electrons) against electron injection from the substrate and smaller trap-assisted tunneling leakage, resulting from improved ZrO{sub 2}/SiO{sub 2} and SiO{sub 2}/Si interfaces.

  16. Reactive sputtering of ?-ZrH{sub 2} thin films by high power impulse magnetron sputtering and direct current magnetron sputtering

    SciTech Connect (OSTI)

    Högberg, Hans Tengdelius, Lina; Eriksson, Fredrik; Broitman, Esteban; Lu, Jun; Jensen, Jens; Hultman, Lars; Samuelsson, Mattias

    2014-07-01

    Reactive sputtering by high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) of a Zr target in Ar/H{sub 2} plasmas was employed to deposit Zr-H films on Si(100) substrates, and with H content up to 61 at.?% and O contents typically below 0.2 at.?% as determined by elastic recoil detection analysis. X-ray photoelectron spectroscopy reveals a chemical shift of ?0.7?eV to higher binding energies for the Zr-H films compared to pure Zr films, consistent with a charge transfer from Zr to H in a zirconium hydride. X-ray diffraction shows that the films are single-phase ?-ZrH{sub 2} (CaF{sub 2} type structure) at H content >?55 at.?% and pole figure measurements give a 111 preferred orientation for these films. Scanning electron microscopy cross-section images show a glasslike microstructure for the HiPIMS films, while the DCMS films are columnar. Nanoindentation yield hardness values of 5.5–7 GPa for the ?-ZrH{sub 2} films that is slightly harder than the ?5 GPa determined for Zr films and with coefficients of friction in the range of 0.12–0.18 to compare with the range of 0.4–0.6 obtained for Zr films. Wear resistance testing show that phase-pure ?-ZrH{sub 2} films deposited by HiPIMS exhibit up to 50 times lower wear rate compared to those containing a secondary Zr phase. Four-point probe measurements give resistivity values in the range of ?100–120 ?? cm for the ?-ZrH{sub 2} films, which is slightly higher compared to Zr films with values in the range 70–80 ?? cm.

  17. Thermal behavior of the amorphous precursors of the ZrO{sub 2}-SnO{sub 2} system

    SciTech Connect (OSTI)

    Stefanic, Goran Music, Svetozar; Ivanda, Mile

    2008-11-03

    Thermal behavior of the amorphous precursors of the ZrO{sub 2}-SnO{sub 2} system on the ZrO{sub 2}-rich side of the concentration range, prepared by co-precipitation from aqueous solutions of the corresponding salts, was monitored using differential thermal analysis, X-ray powder diffraction, Raman spectroscopy, field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectrometry (EDS). The crystallization temperature of the amorphous precursors increased with an increase in the SnO{sub 2} content, from 405 deg. C (0 mol% SnO{sub 2}) to 500 deg. C (40 mol% SnO{sub 2}). Maximum solubility of Sn{sup 4+} ions in the ZrO{sub 2} lattice ({approx}25 mol%) occurred in the metastable products obtained upon crystallization of the amorphous precursors. A precise determination of unit-cell parameters, using both Rietveld and Le Bail refinements of the powder diffraction patterns, shows that the incorporation of Sn{sup 4+} ions causes an asymmetric distortion of the monoclinic ZrO{sub 2} lattice. The results of phase analysis indicate that the incorporation of Sn{sup 4+} ions has no influence on the stabilization of cubic ZrO{sub 2} and negligible influence on the stabilization of tetragonal ZrO{sub 2}. Partial stabilization of tetragonal ZrO{sub 2} in products having a tin content above its solid-solubility limit was attributed to the influence of ZrO{sub 2}-SnO{sub 2} surface interactions. In addition to phases closely structurally related to cassiterite, monoclinic ZrO{sub 2} and tetragonal ZrO{sub 2}, a small amount of metastable ZrSnO{sub 4} phase appeared in the crystallization products of samples with 40 and 50 mol% of SnO{sub 2} calcined at 1000 deg. C. Further temperature treatments caused a decrease in and disappearance of metastable phases. The results of the micro-structural analysis show that the sinterability of the crystallization products significantly decreases with an increase in the SnO{sub 2} content.

  18. Features of an intermetallic n-ZrNiSn semiconductor heavily doped with atoms of rare-earth metals

    SciTech Connect (OSTI)

    Romaka, V. A., E-mail: vromaka@polynet.lviv.ua [National Academy of Sciences of Ukraine, Ya. Pidstryhach Institute for Applied Problems of Mechanics and Mathematics (Ukraine); Fruchart, D.; Hlil, E. K. [CNRS, Institute Neel (France); Gladyshevskii, R. E. [Ivan Franko Lviv National University (Ukraine); Gignoux, D. [CNRS, Institute Neel (France); Romaka, V. V.; Kuzhel, B. S. [Ivan Franko Lviv National University (Ukraine); Krayjvskii, R. V. [Lvivska Politechnika National University (Ukraine)

    2010-03-15

    The crystal structure, density of electron states, electron transport, and magnetic characteristics of an intermetallic n-ZrNiSn semiconductor heavily doped with atoms of rare-earth metals (R) have been studied in the ranges of temperatures 1.5-400 K, concentrations of rare-earth metal 9.5 x 10{sup 19}-9.5 x 10{sup 21} cm{sup -3}, and magnetic fields H {<=} 15 T. The regions of existence of Zr{sub 1-x}R{sub x}NiSn solid solutions are determined, criteria for solubility of atoms of rare-earth metals in ZrNiSn and for the insulator-metal transition are formulated, and the nature of 'a priori doping' of ZrNiSn is determined as a result of redistribution of Zr and Ni atoms at the crystallographic sites of Zr. Correlation between the concentration of the R impurity, the amplitude of modulation of the bands of continuous energies, and the degree of occupation of potential wells of small-scale fluctuations with charge carriers is established. The results are discussed in the context of the Shklovskii-Efros model of a heavily doped and compensated semiconductor.

  19. The photoluminescence properties of Er{sup 3+}-doped ZrO{sub 2} nanotube arrays prepared by anodization

    SciTech Connect (OSTI)

    Wang, Xixin; Zhao, Jianling; Du, Peng; Guo, Limin; Xu, Xuewen; Tang, Chengchun

    2012-11-15

    Graphical abstract: Display Omitted Highlights: ? Er{sup 3+}-doped ZrO{sub 2} nanotube arrays were prepared by anodization of Zr–Er alloy. ? Small tetragonal zirconia crystallites are tended to be formed due to the doping of Er{sup 3+}. ? Under excitation at 317 nm, the ZrO{sub 2} nantube arrays have strongest photoluminescence intensity. -- Abstract: Er{sup 3+}-doped ZrO{sub 2} nanotube arrays were prepared by anodization of Zr–Er alloy which was obtained by melting zirconium with 1.0 wt% erbium. The morphology, structure and photoluminescence properties were studied through scanning electron microscope, transmission electron microscope, X-ray diffraction and photoluminescence analyzer. X-ray diffraction results indicate that doping of Er{sup 3+} affects the crystal structure and grain size obviously and the Er{sup 3+}-doped samples tend to form small tetragonal grains. Photoluminescence analyses show that when Er{sup 3+}-doped zirconia nanotube arrays are excited at 317 nm, there are two strong photoluminescence emission peaks at 373 nm and 415 nm. When the excitation wavelength is 257 nm, a photoluminescence emission peak appears at 363 nm. Under same measurement conditions, emission peaks of the undoped ZrO{sub 2} nanotube arrays are very weak.

  20. Precision vector control of a superconducting RF cavity driven by an injection locked magnetron

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

    Chase, B.; Pasquinelli, R.; Cullerton, E.; Varghese, P.

    2015-03-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons [1]. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs - compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRFmore »cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.« less

  1. Final Technical Report- Back-gate Field Emission-based Cathode RF Electron Gun

    SciTech Connect (OSTI)

    McGuire, Gary; Martin, Allen; Noonan, John

    2010-10-30

    The objective was to complete the design of an electron gun which utilizes a radio frequency (RF) power source to apply a voltage to a field emission (FE) cathode, a so called cold cathode, in order to produce an electron beam. The concept of the RF electron gun was originally conceived at Argonne National Laboratory but never reduced to practice. The research allowed the completion of the design based upon the integration of the FE electron source. Compared to other electron guns, the RF gun is very compact, less than one third the size of other comparable guns, and produces a high energy (to several MeV), high quality, high power electron beam with a long focal length with high repetition rates. The resultant electron gun may be used in welding, materials processing, analytical equipment and waste treatment.

  2. Precision Vector Control of a Superconducting RF Cavity driven by an Injection Locked Magnetron

    E-Print Network [OSTI]

    Brian Chase; Ralph Pasquinelli; Ed Cullerton; Philip Varghese

    2014-11-21

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

  3. Precision Vector Control of a Superconducting RF Cavity driven by an Injection Locked Magnetron

    E-Print Network [OSTI]

    Chase, Brian; Cullerton, Ed; Varghese, Philip

    2015-01-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

  4. Confinement improvement with rf poloidal current drive in the reversed-field pinch

    SciTech Connect (OSTI)

    Hokin, S.; Sarff, J.; Sovinec, C.; Uchimoto, E.

    1994-03-08

    External control of the current profile in a reversed-field pinch (RFP), by means such as rf poloidal current drive, may have beneficial effects well beyond the direct reduction of Ohmic input power due to auxiliary heating. Reduction of magnetic turbulence associated with the dynamo, which drives poloidal current in a conventional RFP, may allow operation at lower density and higher electron temperature, for which rf current drive becomes efficient and the RFP operates in a more favorable regime on the n{tau} vs T diagram. Projected parameters for RFX at 2 MA axe studied as a concrete example. If rf current drive allows RFX to operate with {beta} = 10% (plasma energy/magnetic energy) at low density (3 {times} 10{sup 19} m{sup {minus}3}) with classical resistivity (i.e. without dynamo-enhanced power input), 40 ms energy confinement times and 3 keV temperatures will result, matching the performance of tokamaks of similar size.

  5. Devitrification kinetics and phase selection mechanisms in Cu-Zr metallic glasses

    SciTech Connect (OSTI)

    Kalay, Ilkay

    2010-12-15

    Metallic glasses have been a promising class of materials since their discovery in the 1960s. Indeed, remarkable chemical, mechanical and physical properties have attracted considerable attention, and several excellent reviews are available. Moreover, the special group of glass forming alloys known as the bulk metallic glasses (BMG) become amorphous solids even at relatively low cooling rates, allowing them to be cast in large cross sections, opening the scope of potential applications to include bulk forms and net shape structural applications. Recent studies have been reported for new bulk metallic glasses produced with lower cooling rates, from 0.1 to several hundred K/s. Some of the application products of BMGs include sporting goods, high performance springs and medical devices. Several rapid solidification techniques, including melt-spinning, atomization and surface melting have been developed to produce amorphous alloys. The aim of all these methods is to solidify the liquid phase rapidly enough to suppress the nucleation and growth of crystalline phases. Furthermore, the production of amorphous/crystalline composite (ACC) materials by partial crystallization of amorphous precursor has recently given rise to materials that provide better mechanical and magnetic properties than the monolithic amorphous or crystalline alloys. In addition, these advances illustrate the broad untapped potential of using the glassy state as an intermediate stage in the processing of new materials and nanostructures. These advances underlie the necessity of investigations on prediction and control of phase stability and microstructural dynamics during both solidification and devitrification processes. This research presented in this dissertation is mainly focused on Cu-Zr and Cu-Zr-Al alloy systems. The Cu-Zr binary system has high glass forming ability in a wide compositional range (35-70 at.% Cu). Thereby, Cu-Zr based alloys have attracted much attention according to fundamental research on the behaviors of glass forming alloys. Further motivation arising from the application of this system as a basis for many BMGs and ACC materials; the Cu-Zr system warrants this attention and offers great potential for the development of new materials. However, the prediction and control of microstructural evolution during devitrification remains challenging because of the complex devitrification behavior of the Cu-Zr binary alloy which is arising from the competition of metastable and stable phases and diversity of crystal structures. This dissertation details a systematic fundamental investigation into the mechanisms and kinetics of the various crystallization transformation processes involved in the overall devitrification response of Cu-Zr and Cu-Zr-Al glasses. Various isothermal and nonisothermal treatments are employed, and the structural response is characterized using bulk X-ray and thermal analysis methods as well as nanoscale microscopic analysis methods, revealing structural and chemical details down to the atomic-scale. By carefully combining techniques such as differential scanning calorimetry (DSC), in-situ synchrotron high energy X-ray diffraction (HEXRD), and transmission electron microscopy (TEM) to quantify the characterization transformations, this research has uncovered numerous details concerning the atomistic mechanisms of crystallization and has provided much new understanding related to the dominant phases, the overall reaction sequences, and the rate-controlling mechanisms. As such this work represents a substantial step forward in understanding these transformations and provides a clear framework for further progress toward ultimate application of controlled devitrification processing for the production of new materials with remarkable properties.

  6. Permeability of CoNbZr amorphous thin films over a wide frequency range

    SciTech Connect (OSTI)

    Koyama, H.; Tsujimoto, H.; Shirae, K.

    1987-09-01

    CoNbZr amorphous films have attracted the attention of many researchers because of their high saturation magnetization, high permeability, low coercivity, and nearly zero magnetostriction. For these films to be used, one of the important magnetic properties is the behavior of the permeability over a wide frequency range. We have measured the permeability of a square-shaped magnetic film (13 mm x 55 mm) sputtered on a glass substrate from 1 MHz to 400 MHz using a stripline. Over 400 MHz, the permeability of the magnetic film was measured using a ring-shaped sample mounted in a coaxial fixture. The wall motion permeability of CoNbZr amorphous films decreases from 1 kHz to nearly zero at 1 MHz. The rotation permeability is constant to 100 MHz and ferromagnetic resonance is observed near 1 GHz.

  7. Separate effects identification via casting process modeling for experimental measurement of U–Pu–Zr alloys

    SciTech Connect (OSTI)

    J. Crapps; D. S. DeCroix; J. D. Galloway; D. A. Korzekwa; R. Aikin; R. Fielding; R. Kennedy; C. Unal

    2013-11-01

    Computational simulations of gravity casting processes for metallic U–Pu–Zr nuclear fuel rods have been performed using a design-of-experiments technique to determine the fluid flow, liquid heat transfer, and solid heat transfer parameters which most strongly influence the process solidification speed and fuel rod porosity. The results are used to make recommendations for the best investment of experimental time and effort to measure process parameters.

  8. Irradiation Induced Precipitation and Dissolution of Intermetallics in Zr Alloys Studied Using Synchrotron Radiation

    SciTech Connect (OSTI)

    Arthur T. Motta

    2004-09-21

    The overall aim of this project is to investigate the irradiation induced precipitation of alloying elements and dissolution of second phase particles in Zr alloys using a combination of (1) synchrotron radiation examination of bulk samples using the Advanced Photon Source (APS) at Argonne National Laboratory and (2) in-situ irradiation of model alloys using the IVEM/Tandem Facility also located at Argonne

  9. Buffer Chemical Polishing and RF Testing of the 56 MHz SRF Cavity

    SciTech Connect (OSTI)

    Burrill,A.

    2009-01-01

    The 56 MHz cavity presents a unique challenge in preparing it for RF testing prior to construction of the cryomodule. This challenge arises due to the physical dimensions and subsequent weight of the cavity, and is further complicated by the coaxial geometry, and the need to properly chemically etch and high pressure rinse the entire inner surface prior to RF testing. To the best of my knowledge, this is the largest all niobium SRF cavity to be chemically etched and subsequently tested in a vertical dewar at 4K, and these processes will be the topic of this technical note.

  10. Effect of RF Gradient upon the Performance of the Wisconsin SRF Electron Gun

    SciTech Connect (OSTI)

    Bosch, Robert; Legg, Robert A.

    2013-12-01

    The performance of the Wisconsin 200-MHz SRF electron gun is simulated for several values of the RF gradient. Bunches with charge of 200 pC are modeled for the case where emittance compensation is completed during post-acceleration to 85 MeV in a TESLA module. We first perform simulations in which the initial bunch radius is optimal for the design gradient of 41 MV/m. We then optimize the radius as a function of RF gradient to improve the performance for low gradients.

  11. Intelligent Low-level RF System by Non-destructive Beam Monitoring Device for Cyclotrons

    E-Print Network [OSTI]

    Malafeh, M S Sharifi Asadi; Afarideh, H; Chai, J S

    2015-01-01

    The project of a10MeV PET cyclotron accelerator for medical diagnosis and treatment was started at Amirkabir University of Technology in 2012. The low-level RF system of cyclotron accelerator is designed to stabilize acceleration voltage and control the resonance frequency of the cavity. In this work Intelligent Low Level Radio Frequency Circuit or ILLRF suitable for Most of the AVF cyclotron accelerators was designed by the beam monitoring device and narrow band tunable band-pass filter. In this design, for the RF phase detection does not need to signal processing by microcontroller

  12. A Novel Zr-1Nb Alloy and a New Look at Hydriding

    SciTech Connect (OSTI)

    Robert D. Mariani; James I. Cole; Assel Aitkaliyeva

    2013-09-01

    A novel Zr-1Nb has begun development based on a working model that takes into account the hydrogen permeabilities for zirconium and niobium metals. The beta-Nb secondary phase particles (SPPs) in Zr-1Nb are believed to promote more rapid hydrogen dynamics in the alloy in comparison to other zirconium alloys. Furthermore, some hydrogen release is expected at the lower temperatures corresponding to outages when the partial pressure of H2 in the coolant is less. These characteristics lessen the negative synergism between corrosion and hydriding that is otherwise observed in cladding alloys without niobium. In accord with the working model, development of nanoscale precursors was initiated to enhance the performance of existing Zr-1Nb alloys. Their characteristics and properties can be compared to oxide-dispersion strengthened alloys, and material additions have been proposed to zirconium-based LWR cladding to guard further against hydriding and to fix the size of the SPPs for microstructure stability enhancements. A preparative route is being investigated that does not require mechanical alloying, and 10 nanometer molybdenum particles have been prepared which are part of the nanoscale precursors. If successful, the approach has implications for long term dry storage of used fuel and for new routes to nanoferritic and ODS alloys.

  13. Nano-fabricated superconducting radio-frequency composites, method for producing nano-fabricated superconducting rf composites

    DOE Patents [OSTI]

    Norem, James H.; Pellin, Michael J.

    2013-06-11

    Superconducting rf is limited by a wide range of failure mechanisms inherent in the typical manufacture methods. This invention provides a method for fabricating superconducting rf structures comprising coating the structures with single atomic-layer thick films of alternating chemical composition. Also provided is a cavity defining the invented laminate structure.

  14. Modeling RF Passive Circuits using Coupled Lines and Scalable Models Sidharth Dalmia, Sung Hwan Min and Madhavan Swaminathan

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    the building blocks for other passive structures such as spiral inductors, transformers and capacitors [1Modeling RF Passive Circuits using Coupled Lines and Scalable Models Sidharth Dalmia, Sung Hwan Min.swaminathan@ee.gatech.edu Abstract Coupled line sections are critical structures in distributed RF and microwave passive circuits

  15. Dependence of nuclear spin singlet lifetimes on RF spin-locking power Stephen J. DeVience a,

    E-Print Network [OSTI]

    Rosen, Matthew S

    Dependence of nuclear spin singlet lifetimes on RF spin-locking power Stephen J. DeVience a: Received 6 January 2012 Revised 14 March 2012 Available online 28 March 2012 Keywords: Nuclear singlet of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field

  16. Simulation results of an inductively-coupled rf plasma torch in two and three dimensions for producing a metal matrix composite for nuclear fuel cladding 

    E-Print Network [OSTI]

    Holik III, Eddie Frank (Trey)

    2009-05-15

    I propose to develop a new method for the synthesis of metal matrix composites (MMC) using aerosol reactants in a radio frequency (RF) plasma torch. An inductivelycoupled RF plasma torch (ICPT) may potentially be designed ...

  17. Particle-In-Cell/Monte Carlo Simulation of Ion Back BomBardment in a High Average Current RF Photo-Gun

    E-Print Network [OSTI]

    Qiang, J.

    2010-01-01

    High Average Current RF Photo-Gun J. Qiang Lawrence Berkeleyradio-frequency (RF) photo-gun using a particle-in-cell/ion motion inside the gun so that the ion power deposition

  18. 2004 URSI Meeting, 5-8 January 2004, at the University of Colorado, Boulder, Colorado, USA. Polyimide Planarization for RF-MEMS Switch on PCB

    E-Print Network [OSTI]

    De Flaviis, Franco

    Polyimide Planarization for RF-MEMS Switch on PCB Bahram Ghodsian, C. Jung, B. Cetiner and F. De Flaviis it maintains the high RF-performance of switches. The fabrication process uses polyimide to planerize

  19. Thickness independent reduced forming voltage in oxygen engineered HfO{sub 2} based resistive switching memories

    SciTech Connect (OSTI)

    Sharath, S. U. Kurian, J.; Komissinskiy, P.; Hildebrandt, E.; Alff, L.; Bertaud, T.; Walczyk, C.; Calka, P.; Schroeder, T.

    2014-08-18

    The conducting filament forming voltage of stoichiometric hafnium oxide based resistive switching layers increases linearly with layer thickness. Using strongly reduced oxygen deficient hafnium oxide thin films grown on polycrystalline TiN/Si(001) substrates, the thickness dependence of the forming voltage is strongly suppressed. Instead, an almost constant forming voltage of about 3?V is observed up to 200?nm layer thickness. This effect suggests that filament formation and switching occurs for all samples in an oxidized HfO{sub 2} surface layer of a few nanometer thickness while the highly oxygen deficient thin film itself merely serves as a oxygen vacancy reservoir.

  20. Controlled oxygen vacancy induced p-type conductivity in HfO{sub 2-x} thin films

    SciTech Connect (OSTI)

    Hildebrandt, Erwin; Kurian, Jose; Mueller, Mathis M.; Kleebe, Hans-Joachim; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany); Schroeder, Thomas [IHP, 15236 Frankfurt/Oder (Germany)

    2011-09-12

    We have synthesized highly oxygen deficient HfO{sub 2-x} thin films by controlled oxygen engineering using reactive molecular beam epitaxy. Above a threshold value of oxygen vacancies, p-type conductivity sets in with up to 6 times 10{sup 21} charge carriers per cm{sup 3}. At the same time, the band-gap is reduced continuously by more than 1 eV. We suggest an oxygen vacancy induced p-type defect band as origin of the observed behavior.

  1. Physical properties and band structure of reactive molecular beam epitaxy grown oxygen engineered HfO{sub 2{+-}x}

    SciTech Connect (OSTI)

    Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

    2012-12-01

    We have conducted a detailed thin film growth structure of oxygen engineered monoclinic HfO{sub 2{+-}x} grown by reactive molecular beam epitaxy. The oxidation conditions induce a switching between (111) and (002) texture of hafnium oxide. The band gap of oxygen deficient hafnia decreases with increasing amount of oxygen vacancies by more than 1 eV. For high oxygen vacancy concentrations, defect bands form inside the band gap that induce optical transitions and p-type conductivity. The resistivity changes by several orders of magnitude as a function of oxidation conditions. Oxygen vacancies do not give rise to ferromagnetic behavior.

  2. Room temperature strain rate sensitivity in precursor derived HfO{sub 2}/Si-C-N(O) ceramic nanocomposites

    SciTech Connect (OSTI)

    Sujith, Ravindran; Kumar, Ravi

    2014-01-15

    Investigation on the room temperature strain rate sensitivity using depth sensing nanoindentation is carried out on precursor derived HfO{sub 2}/Si-C-N(O) ceramic nanocomposite sintered using pulsed electric current sintering. Using constant load method the strain rate sensitivity values are estimated. Lower strain rate sensitivity of ? 3.7 × 10{sup ?3} is observed and the limited strain rate sensitivity of these ceramic nanocomposites is explained in terms of cluster model. It is concluded that presence of amorphous Si-C-N(O) clusters are responsible for the limited flowability in these ceramics.

  3. : 8GM-I=8=!"pJsCj=P!"%3!%Q%9Hf3S Analysis on Difficulty Indices

    E-Print Network [OSTI]

    : 8GM-I=8=!"¿pJsCj=P!"%3!¡%Q%9Hf3S Analysis on Difficulty Indices for Japanese Named Entity comparison 1 $O$8$a$K K"8&5f$NL"E*$O!"¿pJsCj=P$N%5%V%?%9%/$G$"$k8GM-I=8=Cj=(Named Entity Task) $NFq0WEY $N$N%o!¡%/%7%g%C%WMessage Understanding Conference (MUC) $G%?%9%/$NDj5A!&I¿2A$,9T$o$l$F$-$?!#8GM-I=8=(Named

  4. Improved nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging

    DOE Patents [OSTI]

    Fukushima, E.; Roeder, S.B.W.; Assink, R.A.; Gibson, A.A.V.

    1984-01-01

    An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

  5. Energy band alignment of atomic layer deposited HfO{sub 2} on epitaxial (110)Ge grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Hudait, M. K.; Zhu, Y. [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Maurya, D.; Priya, S. [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-03-04

    The band alignment properties of atomic layer HfO{sub 2} film deposited on epitaxial (110)Ge, grown by molecular beam epitaxy, was investigated using x-ray photoelectron spectroscopy. The cross-sectional transmission electron microscopy exhibited a sharp interface between the (110)Ge epilayer and the HfO{sub 2} film. The measured valence band offset value of HfO{sub 2} relative to (110)Ge was 2.28 {+-} 0.05 eV. The extracted conduction band offset value was 2.66 {+-} 0.1 eV using the bandgaps of HfO{sub 2} of 5.61 eV and Ge bandgap of 0.67 eV. These band offset parameters and the interface chemical properties of HfO{sub 2}/(110)Ge system are of tremendous importance for the design of future high hole mobility and low-power Ge-based metal-oxide transistor devices.

  6. Photo-induced tunneling currents in MOS structures with various HfO{sub 2}/SiO{sub 2} stacking dielectrics

    SciTech Connect (OSTI)

    Pang, Chin-Sheng; Hwu, Jenn-Gwo

    2014-04-15

    In this study, the current conduction mechanisms of structures with tandem high-k dielectric in illumination are discussed. Samples of Al/SiO{sub 2}/Si (S), Al/HfO{sub 2}/SiO{sub 2}/Si (H), and Al/3HfO{sub 2}/SiO{sub 2}/Si (3H) were examined. The significant observation of electron traps of sample H compares to sample S is found under the double bias capacitance-voltage (C-V) measurements in illumination. Moreover, the photo absorption sensitivity of sample H is higher than S due to the formation of HfO{sub 2} dielectric layer, which leads to larger numbers of carriers crowded through the sweep of V{sub G} before the domination of tunneling current. Additionally, the HfO{sub 2} dielectric layer would block the electrons passing through oxide from valance band, which would result in less electron-hole (e{sup ?}-h{sup +}) pairs recombination effect. Also, it was found that both of the samples S and H show perimeter dependency of positive bias currents due to strong fringing field effect in dark and illumination; while sample 3H shows area dependency of positive bias currents in strong illumination. The non-uniform tunneling current through thin dielectric and through HfO{sub 2} stacking layers are importance to MOS(p) tunneling photo diodes.

  7. Investigation of Zr-doped BSCF perovskite membrane for oxygen separation in the intermediate temperature range

    SciTech Connect (OSTI)

    Ravkina, Olga; Klande, Tobias; Feldhoff, Armin

    2013-05-01

    The series of (Ba?.?Sr?.?)(Co?.?Fe?.?){sub 1–z}Zr{sub z}O{sub 3–?} (z=0, 0.01, 0.03, 0.05, 0.07, and 0.09) was synthesized by a sol–gel method. The materials with a zirconium content up to 3 mol% were found to be single phase. Further increase results in formation of a mixed (Ba,Sr)ZrO? by-phase, which was found along the grain boundaries and in the grains. With increasing zirconium content the oxygen permeation flux decreases considerably. The effect of the zirconium substitution on the long-term phase stability was investigated by long-term oxygen permeation experiments and X-ray diffraction. A slight stabilization of the oxygen flux of (Ba?.?Sr{sub 0.5})(Co?.?Fe?.?)?.??Zr?.??O{sub 3–?} was found after 180 h at 1023 K. However, all compositions show a decrease in permeation flux with time, but the pure BSCF membrane exhibited the strongest drop after 180 h of operation. The decomposition products of the cubic perovskite phase were found to be a hexagonal Ba{sub 0.5±x}Sr{sub 0.5±x}CoO? and a rhombohedral Ba{sub 1–x}Sr{sub x}Co{sub 2–y}Fe{sub y}O{sub 5–?}. - Graphical abstract: Backscattered-electron channeling contrast image of BSCF membrane cross-section after long-term oxygen permeation at 1023 K showing different phases in different colors. Highlights: • Ba?.?Sr?.?Co?.?Fe?.?O{sub 3–?} systematically doped with increasing amount of zirconium. • Cubic single-phase materials up to 3 wt% zirconium. • Mixed (Ba,Sr)ZrO? by-phase formed mainly in the grain boundaries. • Jänecke prism was proposed by XRD and EDXS data. • (Ba?.?Sr?.?)(Co?.?Fe?.?)?.??Zr?.??O{sub 3–?} showed a slight stabilization of oxygen flux as compared to pure Ba?.?Sr?.?Co?.?Fe?.?O{sub 3–?}.

  8. Self-organization during growth of ZrN/SiN{sub x} multilayers by epitaxial lateral overgrowth

    SciTech Connect (OSTI)

    Fallqvist, A.; Fager, H.; Hultman, L.; Persson, P. O. Å.; Ghafoor, N.

    2013-12-14

    ZrN/SiN{sub x} nanoscale multilayers were deposited on ZrN seed layers grown on top of MgO(001) substrates by dc magnetron sputtering with a constant ZrN thickness of 40 Å and with an intended SiN{sub x} thickness of 2, 4, 6, 8, and 15 Å at a substrate temperature of 800 °C and 6 Å at 500 °C. The films were investigated by X-ray diffraction, high-resolution scanning transmission electron microscopy, and energy dispersive X-ray spectroscopy. The investigations show that the SiN{sub x} is amorphous and that the ZrN layers are crystalline. Growth of epitaxial cubic SiN{sub x}—known to take place on TiN(001)—on ZrN(001) is excluded to the monolayer resolution of this study. During the course of SiN{sub x} deposition, the material segregates to form surface precipitates in discontinuous layers for SiN{sub x} thicknesses ?6 Å that coalesce into continuous layers for 8 and 15 Å thickness at 800 °C, and for 6 Å at 500 °C. The SiN{sub x} precipitates are aligned vertically. The ZrN layers in turn grow by epitaxial lateral overgrowth on the discontinuous SiN{sub x} in samples deposited at 800 °C with up to 6 Å thick SiN{sub x} layers. Effectively a self-organized nanostructure can be grown consisting of strings of 1–3 nm large SiN{sub x} precipitates along apparent column boundaries in the epitaxial ZrN.

  9. RE/ZrO{sub 2} (RE = Sm, Eu) composite oxide nano-materials: Synthesis and applications in photocatalysis

    SciTech Connect (OSTI)

    Du, Weimin, E-mail: duweimin75@gmail.com [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); Zhu, Zhaoqiang [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, Henan 450001 (China); Zhang, Xiaofen; Wang, Dacheng; Liu, Donghe [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China); Qian, Xuefeng [School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Du, Jimin, E-mail: djm@aynu.edu.cn [College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455002 (China)

    2013-10-15

    Graphical abstract: - Highlights: • RE/ZrO{sub 2} (RE = Sm, Eu) nano-materials have been successfully synthesized. • Defect and electron structures determine the absorption properties on visible light. • Nano-sized Zr{sub 0.8}Sm{sub 0.2}O{sub 2??} has good visible-light-responsive photocatalytic activities. • In the future, it can be used in wastewater treatment and environmental protection. - Abstract: Zirconia modified by Samarium/Europium, RE/ZrO{sub 2} (RE = Sm, Eu), composite oxide nano-materials have been successfully synthesized by improved sol–gel method. Characterization results show that X-ray diffraction (XRD) peaks of products gradually shift to the lower angle with the increase of rare earth which implies that the lattice distances of RE/ZrO{sub 2} nano-materials are gradually enlarged. Moreover, the molar ratios between zirconium and rare earth are consistent with the chemical formula and both of them are uniformly distributed in samples. Optical properties indicate that defect structures and electron configurations of RE/ZrO{sub 2} (RE = Sm, Eu) with single phase determine their absorption properties on visible light. Photocatalytic experiments indicate Zr{sub 0.8}Sm{sub 0.2}O{sub 2??} nano-crystals have excellent visible-light-responsive photocatalytic activities on Methylene blue and Rhodamine B which results from the special defect structure, suitable electronic configuration, and larger specific surface area. It follows that Zr{sub 0.8}Sm{sub 0.2}O{sub 2??} nano-crystals are new visible-light-responsive photocatalysts which can be applied in dye wastewater treatment and environmental protection in the future.

  10. FIRE Physics Issues 1-3 May 2000 RF Heating Scenarios

    E-Print Network [OSTI]

    1 FIRE Physics Issues 1-3 May 2000 RF Heating Scenarios Dick Majeski, Dave Swain, Mark Carter Princeton Plasma Physics Laboratory and Oak Ridge National Laboratory Physics Issues for FIRE PPPL 1-3 May 2000 #12;2 FIRE Physics Issues 1-3 May 2000 Introduction and requirements FIRE heating and current

  11. RF Power Potential of 90 nm CMOS: Device Options, Performance, and Reliability

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    of the RF power potential of the various device options offered in a state-of-the-art 90 nm CMOS foundry and reliability. In a modern foundry process, in addition to the nominal digital devices, it is common to offer in a foundry process. Technology The technology that has been studied in this work is a foundry 90 nm CMOS

  12. A Measurement Study of Zigbee-based Indoor Localization Systems Under RF Interference

    E-Print Network [OSTI]

    Huang, Polly

    A Measurement Study of Zigbee-based Indoor Localization Systems Under RF Interference Seng 802.11) and Zigbee (IEEE 802.15.4) all operate in the 2.4x GHz fre- quency bands. The stability and availability of RSSI infor- mation for WiFi- or Zigbee-based localization systems may vary depending

  13. Green radio despite "Dirty RF" front-end Myriam Ariaudo*1

    E-Print Network [OSTI]

    Fijalkow, Inbar

    design, which reduces the chip area and the number of components (Green #12;design) or facilitate. Concerning the RF part, designing a Green radio first consists in the improvement of efficiency. It is well front-end imperfections can participate in the design of Green radio. Some of these corrections enable

  14. High Power RF Tests on WR650 Pre-Stressed Planar Windows

    SciTech Connect (OSTI)

    Stirbet, Mircea [JLAB; Davis, G. Kirk [JLAB; Elliott, Thomas S. [JLAB; King, Larry [JLAB; Powers, Thomas J. [JLAB; Rimmer, Robert A. [JLAB; Walker, Richard L. [JLAB

    2009-11-01

    A new planar, ceramic window intended to be used with WR650 waveguide fundamental power couplers at 1300 MHz or 1500 MHz has been developed. It is based on the pre-stressed planar window concept tested in PEP II and LEDA. A test stand that made use of the 100kW CW 1500 MHz RF system in the JLAB FEL was commissioned and used to apply up to 80 kW traveling wave (TW)to the windows. Two different types of RF windows (brazed and diffusion bonded ceramics) with design specification of 50 kW CW in TW mode were successfully tested both as a gas barrier (intended to operate up to 2 psi) and as a vacuum barrier. The vacuum windows were able to maintain UHV quality vacuum and were successfully operated in the 10{sup -9} mbar range. An overview of the pre-stressed power windows, RF test stand, procedures and RF power testing results will be presented.

  15. Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens and Katia Sycara

    E-Print Network [OSTI]

    Scerri, Paul

    Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens and Katia Sycara efficient way for a team of UAVs with Received Signal Strength Indicator (RSSI) sen- sors to locate radio locations requires integrating multiple signals from different UAVs into a Bayesian filter, hence requir

  16. CMOS RF front-end design for terrestrial and mobile digital television systems 

    E-Print Network [OSTI]

    Xiao, Jianhong

    2007-09-17

    of the mobile DVB-H tuner, a novel RF variable gain amplifier (RFVGA) and a low flicker noise current-mode passive mixer have been proposed. The proposed RFVGA achieves high dynamic range and robust input impedance matching performance, which is the main design...

  17. Resolved dynamics of single electron tunneling using the RF-SET Julie Helen Love

    E-Print Network [OSTI]

    Devoret, Michel H.

    .4 Tunneling Rates in the single Electron Trap . . . . . . . . . . . . . . . . . . . . . . . 49 5 CotunnellingAbstract Resolved dynamics of single electron tunneling using the RF-SET Julie Helen Love 2007 This thesis presents measurements of time resolved single electron tunneling events in a metallic thin film

  18. Use of THz Photoconductive Sources to Characterize Tunable Graphene RF Plasmonic

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    1 Use of THz Photoconductive Sources to Characterize Tunable Graphene RF Plasmonic Antennas A. Cabellos, I. Llatser, E. Alarc´on, A. Hsu and T. Palacios Abstract--Graphene, owing to its ability challenges in the characterization and demonstration of graphene antennas is finding suitable terahertz

  19. Power Reduction of CMP Communication Networks via RF-Interconnects M-C. Frank Chang

    E-Print Network [OSTI]

    Cong, Jason "Jingsheng"

    Power Reduction of CMP Communication Networks via RF-Interconnects M-C. Frank Chang , Jason Cong multiprocessors scale to a greater number of processing cores, on-chip interconnection networks will ex- perience dramatic increases in both bandwidth demand and power dissipation. Fortunately, promising gains can be re

  20. Proc 12th conf. RF Power in Plasmas, Savannah, 1997 Ion-Bernstein Wave Mode Conversion

    E-Print Network [OSTI]

    Jaun, André

    Proc 12th conf. RF Power in Plasmas, Savannah, 1997 Ion-Bernstein Wave Mode Conversion in Hot-Bernstein wave can dramatically affect the power profile and partition among the species. The results obtained very different wavelengths. Where the spa- tial scale of two waves match, the power associated with one

  1. Diagnostics of ballistic electrons in a dc/rf hybrid capacitively coupled discharge

    E-Print Network [OSTI]

    Economou, Demetre J.

    Diagnostics of ballistic electrons in a dc/rf hybrid capacitively coupled discharge Lin Xu,1,a Lee the substrate electrode or the semiconduc- tor wafer. Watanabe et al.7 superimposed a high energy electron beam. Economou,2,c and Vincent M. Donnelly2,d 1 Tokyo Electron America, Austin, Texas 78741, USA 2 Department

  2. Realization and Modeling of Metamaterials Made of rf Superconducting Quantum-Interference Devices

    E-Print Network [OSTI]

    Anlage, Steven

    ,5], cloaking [6,7], transformation optics [8,9], and perfect absorption [10]. Most of the applications invoking in space (e.g., for cloaking or transformation optics) or that can be tuned and reconfigured after for digital rf receivers [25,26]. Superconducting metamaterials have been proposed to address all three

  3. On the Placement of RF Energy Harvesting Node in Wireless Networks with Secrecy Considerations

    E-Print Network [OSTI]

    Zhou, Xiangyun "Sean"

    On the Placement of RF Energy Harvesting Node in Wireless Networks with Secrecy Considerations Biao of harvesting wireless energy, it is desirable to have the EH node located close to the transmitter. However approach to reduce the energy consumption and prolong the lifetime of wireless networks. Apart from

  4. Optimization and Characterization of RF Sputtered Piezoelectric Zinc Oxide Thin Film for

    E-Print Network [OSTI]

    Tang, William C

    Oxide (ZnO) thin films had been found to have unique piezoelectric effect for the applicationsOptimization and Characterization of RF Sputtered Piezoelectric Zinc Oxide Thin Film for Transducer Applications Yu-Hsiang Hsu, John Lin, and William C. Tang* Department of Biomedical Engineering University

  5. NON-RECIPROCAL SAW DEVICES FOR RF APPLICATIONS M. Rotter, W. Ruile

    E-Print Network [OSTI]

    Ludwig-Maximilians-Universität, München

    NON-RECIPROCAL SAW DEVICES FOR RF APPLICATIONS M. Rotter, W. Ruile Siemens AG, Corporate Technology of a semiconductor heterostructure and the acoustic properties of strongly piezoelectric crystals yields promising hybrids for potential acousto electric applications. The nonlinear interaction between an intense SAW

  6. UNI\\'ERSm RF..olS'l'UAR BACHELOR OF SCIENCE IN BIOCHEMISTRY

    E-Print Network [OSTI]

    Virginia Tech

    APPPO'T.D UNI\\'ERSm RF..olS'l'UAR BACHELOR OF SCIENCE IN BIOCHEMISTRY COLLEGE OF SCIENCE GRADUATION: Scientific Reasoning and Discovery (Natural Sciences): BeRM 1014 Introduction to Biochemistry General Biochemistry Lab. Prob. Biochemistry (1)_ (4)_ (3)_ (6)_ #BCHM 4115 4116 #BCHM 4124 #12;BlOC 2013 BIOL 1105 l

  7. Performance Analysis of Ambient RF Energy Harvesting: A Stochastic Geometry Approach

    E-Print Network [OSTI]

    Privault, Nicolas

    proposed as a potential solution to provide proactive energy replenishment for wireless devices. This paper aims to analyze the performance of a battery-free wireless sensor powered by ambient RF energy signals into electricity. Therefore, it has recently emerged as an alternative method to operate low

  8. Electromechanical Modeling and Simulation of RF MEMS Switches Yong Zhu and Horacio D. Espinosa

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Electromechanical Modeling and Simulation of RF MEMS Switches Yong Zhu and Horacio D. Espinosa the electromechanical behavior of a fixed-fixed switch. However, in some practical applications, multi and discuss their electromechanical performances. The switch, bottom electrode and surrounding air were all

  9. RF Distribution System for High Power Test of the SNS Cryomodule

    SciTech Connect (OSTI)

    Lee, Sung-Woo [ORNL] [ORNL; Kang, Yoon W [ORNL] [ORNL; Broyles, Michael R [ORNL] [ORNL; Crofford, Mark T [ORNL] [ORNL; Geng, Xiaosong [ORNL] [ORNL; Kim, Sang-Ho [ORNL] [ORNL; Phibbs, Curtis L [ORNL] [ORNL; Strong, William Herb [ORNL] [ORNL; Peglow, Robert C [ORNL] [ORNL; Vassioutchenko, Alexandre V [ORNL] [ORNL

    2012-01-01

    A four-way waveguide RF power distribution system for testing the Spallation Neutron Source (SNS) multi-cavity cryomodule to investigate the collective behavior has been developed. A single klystron operating at 805MHz for 1.3 msec at 60Hz powers the 4-way waveguide splitter to deliver up to 400 kW to individual cavities. Each cavity is fed through a combination of waveguide splitters and vector modulators (VM) to provide independent magnitude and phase controls. The waveguide vector modulator consists of two quadrature hybrids and two motorized waveguide phase shifters. The phase shifters and the assembled waveguide vector modulators were individually tested and characterized for low power and high RF power in the SNS RF test facility. Precise calibrations of magnitude and phase were performed to generate the look up tables (LUTs) to provide operational references during the cryomodule test. An I-Q demodulator module was developed and utilized to measure relative phases in pulsed high RF power operation. PLC units were developed for mechanical control of the phase shifters. Initial low/high power measurements were made using LabVIEW. An operation algorithm has been implemented into EPICS control for the cryomodule test stand.

  10. Aspect Ratio Dependence of Bootstrap Current and RF Current Driving Efficiency

    E-Print Network [OSTI]

    Boyer, Edmond

    . Ashidaa a National Institute of advanced Industrial Science and Technology, Tsukuba, Japan, b Nihon University, Institute of Quantum Science, Tokyo, Japan, c Nihon University, College of Industrial Technology pinch (RFP) with the low aspect ratio of A = 2.0, then significantly reduces the rf-driven current

  11. S-Band Waveguide Reconfiguration Options for the LCLS RF Gun and L0 Klystron Feeds

    SciTech Connect (OSTI)

    McIntosh, P.

    2005-01-28

    This note highlights the possible re-configuration options for the existing WR284 S-band waveguide in the klystron gallery, to enable those existing 5045 klystrons to power the RF Gun and the L0 accelerating structures for LCLS. A reconfiguration decision based on the pros and cons for each option is subsequently identified.

  12. TESLA Report 2004-02 Anti-multipactor TiN coating of RF power

    E-Print Network [OSTI]

    N layers generation on surfaces which were not protected in this way previously. Thin TiN films on ceramicTESLA Report 2004-02 1 Anti-multipactor TiN coating of RF power coupler components for TESLA performance of couplers) J. Lorkiewicz1 , The Andrzej Soltan Institute for Nuclear Studies, Pl 05-400 Otwock

  13. Localization algorithms for sensor networks using RF signal CS 252 Class Project

    E-Print Network [OSTI]

    Nguyen, Long

    Localization algorithms for sensor networks using RF signal strength CS 252 Class Project Xuan represent a future branch of computer architecture research. As Moore's law continues to drive more and more in wireless node distance estimation. Then, based on characteristics of this distance estimation, we develop

  14. Ion Crystals Produced by Laser and Sympathetic Cooling in a Linear RF Ion Trap 

    E-Print Network [OSTI]

    Zhu, Feng

    2012-02-14

    A detailed investigation of ion crystals produced by laser and sympathetic cooling in a linear RF trap has been conducted. The laser cooling methods were examined and applied to the trapped ^24Mg^(positive) ions. The crystals produced by the laser...

  15. Identification of Residual Stress State in an RF-MEMS Device

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Identification of Residual Stress State in an RF-MEMS Device l Horacio D. Espinosa, M. Fischer Dept Microelectromechanical Systems (MEMS) are among the most significant technological advances of this decade. The objective is of a few nanometers. The study of "thin films" and "ultra thin films" employed in MEMS devices is being

  16. WTJ(S^rf7?\\ Ris-R-761p*

    E-Print Network [OSTI]

    WTJ(S^rf7?\\ Risø-R-761£p*Thermonuclear Fusion September 1994 #12;ANNUAL PROGRESS _****ig*r REPORT 1993 Work in Controlled Thermonuclear Fusion Research Research Performed in The Fusion Research Unit underthe Contract ofAssociationbetween Euratom and Risø

  17. Epitaxial growth of lead zirconium titanate thin films on Ag buffered Si substrates using rf sputtering

    E-Print Network [OSTI]

    Laughlin, David E.

    Epitaxial growth of lead zirconium titanate thin films on Ag buffered Si substrates using rf 7 February 2007; accepted 25 March 2007; published online 23 April 2007 Epitaxial lead zirconium American Institute of Physics. DOI: 10.1063/1.2731515 The ferroelectric material lead zirconium titanate Pb

  18. Feedback based Sparse Recovery for Motion Tracking in RF Sensor Networks

    E-Print Network [OSTI]

    Qiu, Robert Caiming

    Feedback based Sparse Recovery for Motion Tracking in RF Sensor Networks Heping Song #1 , Tong Liu #2 , Xiaomu Luo #3 , Guoli Wang #4 # School of Information Science and Technology, Sun Yat tracking with radio tomographic networks using received signal strength (RSS) measurements has attracted

  19. Ion transport in macroscopic RF linear traps Jofre Pedregosa-Gutierrez,

    E-Print Network [OSTI]

    Boyer, Edmond

    ´er^ome, 13397 Marseille Cedex 20, France (Dated: July 18, 2014) Abstract Efficient transport of cold atomsIon transport in macroscopic RF linear traps Jofre Pedregosa-Gutierrez, Caroline Champenois, Marius information processing to frequency metrology. Different transport schemes have been developed, which allow

  20. Reflective Cracking Study: First-level Report on HVS Testing on Section 591RF - 45 mm MAC15TR-GOverlay

    E-Print Network [OSTI]

    Jones, David; Wu, R.; Harvey, John T

    2008-01-01

    Testing on Section 588RF — 90 mm AR4000-D Overlay (UCPRC-RR-Testing on Section 586RF — 45 mm MB15-G Overlay (UCPRC-RR-Testing on Section 591RF — 45 mm MAC15TR-G Overlay (UCPRC-