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1

Ternary ceramic alloys of Zr-Ce-Hf oxides  

DOE Patents (OSTI)

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.

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

1990-11-20T23:59:59.000Z

2

ACCEPTED MANUSCRIPT The behaviour of Rare-Earth Elements, Zr and Hf during biologically-mediated  

E-Print Network (OSTI)

ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 1 The behaviour of Rare-Earth Elements, Zr and Hf during.a,b* , Cangemi M.a , Brusca L.c , Madonia P.c , Saiano F.d , Zuddas P.e a) Department of Earth and Marine at the solid-liquid interface influencing the distribution of trace elements onto microbial surfaces. Since

3

Stress effects on superconducting properties of the composite-processed V/sub 2/(Hf,Zr)  

SciTech Connect

The superconducting critical current I/sub c/ (4.2 K) of V/sub 2/(Hf,Zr) composite tape was measured under tensile load. I/sub c/ values of the V/sub 2/(Hf,Zr) composite tape do not change at all up to a strain level of 0.55%, and then decrease irreversibly with respect to strain, although the stress-strain curves for these tapes exhibit no irreversible behavior. Many cracks were observed in the V/sub 2/(Hf,Zr) layer of the composite tape strained up to 0.6%. Thermal expansion data indicate that the residual tensile stress may be produced in the V/sub 2/(Hf,Zr) layer by the large thermal contraction of the layer and may reduce the strain tolerance of the composite tape.

Inoue, K.; Wada, H.; Kuroda, T.; Tachikawa, K.

1981-06-01T23:59:59.000Z

4

Electronic structure and magnetic susceptibility of the different structural modifications of Ti, Zr, and Hf metals  

Science Journals Connector (OSTI)

The electronic structure of the early transition metals Ti, Zr, and Hf has been investigated for the hexagonal (?), hcp (?), bcc (?), and fcc phases using the linear-muffin-tin-orbital method of band-structure calculation. The results of these investigations are discussed in the light of previous band-structure calculations and experimental data closely related to the electronic structure (low-temperature specific heat, superconductive properties and magnetic susceptibility). It is found from the theoretical calculations that the electronic density of states at the Fermi level increases in the phase sequence hexagonal (?)?hcp (?)?fcc?bcc (?) and this behavior is unambiguously reflected in all the experimental data as well. A separation of the magnetic susceptibility into its components is performed and from this, the temperature dependence of the Pauli susceptibility for Ti, Zr, and Hf is deduced.

I. Bakonyi, H. Ebert, and A. I. Liechtenstein

1993-09-15T23:59:59.000Z

5

Ternary ceramic alloys of ZR-CE-HF oxides  

DOE Patents (OSTI)

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.

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

1990-01-01T23:59:59.000Z

6

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

E-Print Network (OSTI)

Transition metal carbides, including the NaCl-structured group IV Ti, Zr, and Hf carbides, have extremely of oxidizing agents, and retain good corrosion resistance to high temperature.1,5,6 The transition-metal high melting points and are therefore referred to collectively as the "refractory carbides

Steinle-Neumann, Gerd

7

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

E-Print Network (OSTI)

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

Jones, William D.

8

Plasma analyses during femtosecond laser ablation of Ti, Zr, and Hf  

SciTech Connect

Femtosecond laser ablation of Ti, Zr, and Hf has been investigated by means of in situ plasma diagnostics. Fast imaging was used to characterize the plasma plume expansion on a nanosecond time scale. In addition, time- and space-resolved optical emission spectroscopy was employed to determine the plume composition and the characteristic expansion velocities of plasma species. It is shown that two plume components with different expansion velocities are generated by the interaction of ultrashort laser pulses with metals. The composition and the expansion behavior of the two components have been analyzed as a function of laser fluence and target material. The results are discussed in terms of mechanisms responsible for ablation by ultrashort laser pulses.

Grojo, D.; Hermann, J.; Perrone, A. [LP3-UMR 6182 Centre National de la Recherche Scientifique, Faculte des Sciences de Luminy, Case 917, 13288 Marseille Cedex 9 (France); University of Lecce, Physics Department and National Nanotechnology Laboratory, 73100-Lecce (Italy)

2005-03-15T23:59:59.000Z

9

Thermal properties of La2O3-doped ZrB2- and HfB2-based ultra-high temperature ceramics  

Science Journals Connector (OSTI)

Abstract Thermal properties of La2O3-doped ZrB2- and HfB2-based ultra high temperature ceramics (UHTCs) have been measured at temperatures from room temperature to 2000C and compared with SiC-doped ZrB2- and HfB2-based \\{UHTCs\\} and monolithic ZrB2 and HfB2. Thermal conductivities of La2O3-doped \\{UHTCs\\} remain constant around 5560W/mK from 1500C to 1900C while SiC-doped \\{UHTCs\\} showed a trend to decreasing values over this range.

E. Zapata-Solvas; D.D. Jayaseelan; P.M. Brown; W.E. Lee

2013-01-01T23:59:59.000Z

10

Effect of strain on the critical parameters of V/sub 2/(Hf, Zr) Laves phase composite superconductors  

SciTech Connect

Strain effects on the critical parameters of composite-processed V/sub 2/(Hf, Zr) Laves phase superconductors have been examined. The critical temperature is found to be insensitive to the strain induced by the thermal differential contraction between the composite components. Critical current versus uniaxial strain curves obtained are completely flat at magnetic fields up to 19 T. It also turns out that the bulk upper critical field shows essentially no sensitivity to uniaxial strain. These results, which are quite different from those reported for A15 compound superconductors, are discussed in terms of the structural insensitivity of the Laves phase superconductor. Fractography suggests that the mechanical properties of V/sub 2/(Hf, Zr) composite conductors may be improved by the grain refinement of component alloys.

Wada, H.; Inoue, K.; Tachikawa, K.; Ekin, J.W.

1982-05-01T23:59:59.000Z

11

Memory functions of nanocrystalline cadmium selenide embedded ZrHfO high-k dielectric stack  

SciTech Connect

Metal-oxide-semiconductor capacitors made of the nanocrystalline cadmium selenide nc-CdSe embedded Zr-doped HfO{sub 2} high-k stack on the p-type silicon wafer have been fabricated and studied for their charge trapping, detrapping, and retention characteristics. Both holes and electrons can be trapped to the nanocrystal-embedded dielectric stack depending on the polarity of the applied gate voltage. With the same magnitude of applied gate voltage, the sample can trap more holes than electrons. A small amount of holes are loosely trapped at the nc-CdSe/high-k interface and the remaining holes are strongly trapped to the bulk nanocrystalline CdSe site. Charges trapped to the nanocrystals caused the Coulomb blockade effect in the leakage current vs. voltage curve, which is not observed in the control sample. The addition of the nanocrystals to the dielectric film changed the defect density and the physical thickness, which are reflected on the leakage current and the breakdown voltage. More than half of the originally trapped holes can be retained in the embedded nanocrystals for more than 10 yr. The nanocrystalline CdSe embedded high-k stack is a useful gate dielectric for this nonvolatile memory device.

Lin, Chi-Chou; Kuo, Yue [Thin Film Nano and Microelectronics Research Laboratory, Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, Texas 77843-3122 (United States)

2014-02-28T23:59:59.000Z

12

Local elastic modulus of RF sputtered HfO{sub 2} thin film by atomic force acoustic microscopy  

SciTech Connect

Atomic force acoustic microscopy (AFAM) is a useful nondestructive technique for measurement of local elastic modulus of materials at nano-scale spatial resolution by measuring the contact resonance spectra for higher order modes of the AFM cantilever. The elastic modulus of RF sputtered HfO{sub 2} thin film has been measured quantitatively, using reference approach in which measurements are performed on the test and reference samples. Using AFAM, the measured elastic modulus of the HfO{sub 2} thin film is 22327 GPa, which is in agreement with the literature value of 22040 GPa for atomic layer deposited HfO{sub 2} thin film using nanoindentation technique.

Jena, S., E-mail: shuvendujena9@gmail.com; Tokas, R. B., E-mail: shuvendujena9@gmail.com; Sarkar, P., E-mail: shuvendujena9@gmail.com; Thakur, S.; Sahoo, N. K. [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Misal, J. S.; Rao, K. D. [Optics and Thin Film Laboratory, Autonagar, BARC-Vizag, Visakhapatnam-530 012 (India)

2014-04-24T23:59:59.000Z

13

Experimental and theoretical studies on the C15 intermetallic compounds MV{sub 2} (M = Zr, Hf and Ta): Elasticity and phase stability  

SciTech Connect

The phase stability of C15 HfV{sub 2} was studied by specific heat measurements. The elastic constants of C15 HfV{sub 2} were measured by the resonant ultrasound spectroscopy. Total energy and electronic structure of C15 intermetallic compounds MV{sub 2} (M = Zr, Hf and Ta) were calculated using the linear muffin tin orbital (LMTO) method. The band structures at X-point near the Fermi level were used to understand the anomalous shear moduli of the C15 HfV{sub 2} and ZrV{sub 2}. It was found that the double degeneracy with a linear dispersion relation of electronic levels at the x-point near the Fermi surface is mainly responsible for the C15 anomalous elasticity at high temperatures. The densities of states at Fermi level and the geometry of the Fermi surface were used to explain the low temperature phase instability of C15 HfV{sub 2} and ZrV{sub 2} and the stability of C15 TaV{sub 2}. The relationship between the anomalous elasticity and structural instability of C15 HfV{sub 2} and ZrV{sub 2} were also studied.

Chu, F.; Mitchell, T.E.; Chen, S.P. [Los Alamos National Lab., NM (United States); Sob, M.; Siegl, R.; Pope, D.P. [Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Materials Science and Engineering

1994-12-01T23:59:59.000Z

14

Two-Dimensional Polaronic Behavior in the Binary Oxides m-HfO2 and m-ZrO2  

SciTech Connect

We demonstrate that the three-dimensional (3D) binary monoclinic oxides HfO{sub 2} and ZrO{sub 2} exhibit quasi-2D polaron localization and conductivity, which results from a small difference in the coordination of two oxygen sublattices in these materials. The transition between a 2D large polaron into a zero-dimensional small polaron state requires overcoming a small energetic barrier. These results demonstrate how a small asymmetry in the lattice structure can determine the qualitative character of polaron localization and significantly broaden the realm of quasi-2D polaron systems.

McKenna, K. P.; Wolf, M. J.; Shluger, A. L.; Lany, S.; Zunger, A.

2012-03-16T23:59:59.000Z

15

Thermal stability of Al- and Zr-doped HfO{sub 2} thin films grown by direct current magnetron sputtering  

SciTech Connect

Ultrathin HfO{sub 2} dielectric films doped with Al and Zr were grown on p-type Si(100) substrates by dc magnetron sputtering, and their microstructural and electrical properties were examined. Compositions and chemical states of the dielectric films were analyzed by Rutherford backscattering spectrometry and x-ray photoelectron spectroscopy. The HfO{sub 2} films doped with Zr were crystallized even from the as-deposited state, however, the crystallization temperature of the HfO{sub 2} film doped with 16% Al{sub 2}O{sub 3} was delayed up to 900 deg. C. As the annealing temperature increases, high-resolution transmission electron microscopy analyses of all doped HfO{sub 2} films showed an increase of the interfacial layer thickness due to the diffusion of small partial pressure of oxygen in annealing ambient. Our results also showed that the addition of Al{sub 2}O{sub 3} to 14% is not useful for blocking the oxygen diffusion through the (HfO{sub 2}){sub 0.86}(Al{sub 2}O{sub 3}){sub 0.14} film. From the capacitance-voltage measurements, the dielectric constants of the Al- and Zr-doped HfO{sub 2} thin films were measured to be 18.7 and 7.6, respectively.

Hong, Yeong-Eui; Kim, Yong-Seok; Do, Kihoon; Lee, Dongwon; Ko, Dae-Hong; Ku, Ja-Hum; Kim, Hyoungsub [Department of Ceramic Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-749 (Korea, Republic of); Semiconductor R and D Division, Samsung Electronics Co, Ltd., San no. 24, Nongseo-Ri, Kiheung-Eup, Yongin-City, Kyunggi-Do 449-711 (Korea, Republic of); Department of Advanced Materials Engineering, Sungkyunkwan University, 300 Chunchun-Dong, Jangan-Ku, Suwon 440-746 (Korea, Republic of)

2005-09-15T23:59:59.000Z

16

Activation Volume for Hf Diffusion in an Amorphous Ni0.54Zr0.46 Alloy  

Science Journals Connector (OSTI)

In this Letter we present the results of a diffusion study of Hf in a Ni0.54Zr0.46 amorphous alloy. We have measured the diffusion properties with and without pressure, up to 1 GPa. From these measurements we can deduce an Arrhenius behavior of the diffusion, with an activation energy of 0.76 eV and a pre-exponential factor of 7.410-17 m2/s. The activation volume amounts to 8.5 ?3. Activation volume and energy are related by the Keyes relationship. We then discuss to what extent presently proposed diffusion mechanisms, point defects, or collective processes can be tested against these results.

A. Grandjean; P. Blanchard; Y. Limoge

1997-01-27T23:59:59.000Z

17

rf  

NLE Websites -- All DOE Office Websites (Extended Search)

RF RF It's what makes the protons go 'round. The latest in a series explaining particle physics in everyday language. Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

18

Temperature dependences of superconducting critical current density and upper critical field for V/sub 2/(Hf,Zr) multifilamentary wire  

SciTech Connect

The temperature dependences of the critical current density, J /SUB c/ , and the upper critical field, uH /SUB c2/ , have been studied for newly developed V/sub 2/(Hf,Zr) multifilamentary wires. At 4.2 K, a ..mu..H /SUB c2/ of 22 T and an overall J /SUB c/ of 1 x 10/sup 4/ A/cm/sup 2/ at 17 T are obtained for these wires. At 1.8 K, overall J /SUB c/ in 15 T of these wires are twice as large as that of the bronze-processed Nb/sub 3/Sn multifilamentary wire. The enhanced J /SUB c/ at reduced temperatures may be attributed to the rapid increase in ..mu..H /SUB c2/ by using the temperature scaling law of the pinning force density. ..mu..H /SUB c2/ measured in pulsed fields is about 28 T at 2.0 K. According to the temperature scaling law, the overall J /SUB c/ for 1.8 K and at 20 T is estimated to be 2 x 10/sup 4/ A/cm/sup 2/. Thus, the present V/sup 2/(Hf,Zr) multifilamentary wires are very promising for use of generating high magnetic fields in the superfluid liquid helium environment.

Inoue, K.; Kuroda, T.; Tachikawa, K.

1985-03-01T23:59:59.000Z

19

Optical spectroscopic study of the SiN/HfO{sub 2} interfacial formation during rf sputtering of HfO{sub 2}  

SciTech Connect

High-k stacks formed by chemical-vapor-deposited SiN and high-pressure sputtered HfO{sub 2} in either O{sub 2} or Ar atmosphere have been studied. The introduction of a SiN layer is proposed to prevent the uncontrollable SiO{sub 2} growth while sputtering. The formation of Si-O bonds after the sputtering of the HfO{sub 2} film in O{sub 2} atmosphere was observed by infrared spectroscopy. Optical diagnosis of the plasma demonstrated a high density of O radicals in the system when working with O{sub 2}. The small radius and high reactivity of these O radicals are the source of the SiN oxidation. However, the structure of the SiN film is preserved during Ar sputtering.

Toledano-Luque, M.; Lucia, M. L.; Prado, A. del; San Andres, E.; Martil, I.; Gonzalez-Diaz, G. [Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, Ciudad Universitaria, E-28040 Madrid (Spain)

2007-11-05T23:59:59.000Z

20

Thermal and electronic charge transport in bulk nanostructured Zr{sub 0.25}Hf{sub 0.75}NiSn composites with full-Heusler inclusions  

SciTech Connect

Bulk Zr{sub 0.25}Hf{sub 075}NiSn half-Heusler (HH) nanocomposites containing various mole fractions of full-Heusler (FH) inclusions were prepared by solid state reaction of pre-synthesized HH alloy with elemental Ni at 1073 K. The microstructures of spark plasma sintered specimens of the HH/FH nanocomposites were investigated using transmission electron microscopy and their thermoelectric properties were measured from 300 K to 775 K. The formation of coherent FH inclusions into the HH matrix arises from solid-state Ni diffusion into vacant sites of the HH structure. HH(1-y)/FH(y) composites with mole fraction of FH inclusions below the percolation threshold, y{approx}0.2, show increased electrical conductivity, reduced Seebeck coefficient and increased total thermal conductivity arising from gradual increase in the carrier concentration for composites. A drastic reduction ({approx}55%) in {kappa}{sub l} was observed for the composite with y=0.6 and is attributed to enhanced phonon scattering due to mass fluctuations between FH and HH, and high density of HH/FH interfaces. - Graphical abstract: Large reduction in the lattice thermal conductivity of bulk nanostructured half-Heusler/full-Heusler (Zr{sub 0.25}Hf{sub 075}NiSn/ Zr{sub 0.25}Hf{sub 075}Ni{sub 2}Sn) composites, obtained by solid-state diffusion at 1073 K of elemental Ni into vacant sites of the half-Heusler structure, arising from the formation of regions of spinodally decomposed HH and FH phases with a spatial composition modulation of {approx}2 nm. Highlights: > Bulk composites from solid state transformation of half-Heusler matrix through Ni diffusion. > Formation of coherent phase boundaries between half-Heusler matrix and full-Heusler inclusion. > Alteration of thermal and electronic transports with increasing full-Heusler inclusion. > Enhanced phonon scattering at half-Heusler/ full-Heusler phase boundaries.

Makongo, Julien P.A.; Misra, Dinesh K. [Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Salvador, James R. [Chemical Sciences and Materials Systems Laboratory, General Motors R and D Center, Warren, MI 48090 (United States); Takas, Nathan J. [Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Wang, Guoyu [Department of Physics, University of Michigan, Ann Arbor, MI 48109 (United States); Shabetai, Michael R.; Pant, Aditya; Paudel, Pravin [Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Uher, Ctirad [Department of Physics, University of Michigan, Ann Arbor, MI 48109 (United States); Stokes, Kevin L. [Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Department of Physics, University of New Orleans, New Orleans, LA 70148 (United States); Poudeu, Pierre F.P., E-mail: ppoudeup@umich.edu [Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States); Laboratory for Emerging Energy and Electronic Materials, Materials Science and Engineering Department, University of Michigan, Ann Arbor, MI 48109 (United States)

2011-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Exploration of R2XM2 (R=Sc, Y, Ti, Zr, Hf, rare earth; X=main group element; M=transition metal, Si, Ge): Structural Motifs, the novel Compound Gd2AlGe2 and Analysis of the U3Si2 and Zr3Al2 Structure Types  

SciTech Connect

In the process of exploring and understanding the influence of crystal structure on the system of compounds with the composition Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} several new compounds were synthesized with different crystal structures, but similar structural features. In Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}, the main feature of interest is the magnetocaloric effect (MCE), which allows the material to be useful in magnetic refrigeration applications. The MCE is based on the magnetic interactions of the Gd atoms in the crystal structure, which varies with x (the amount of Si in the compound). The crystal structure of Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} can be thought of as being formed from two 3{sup 2}434 nets of Gd atoms, with additional Gd atoms in the cubic voids and Si/Ge atoms in the trigonal prismatic voids. Attempts were made to substitute nonmagnetic atoms for magnetic Gd using In, Mg and Al. Gd{sub 2}MgGe{sub 2} and Gd{sub 2}InGe{sub 2} both possess the same 3{sup 2}434 nets of Gd atoms as Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}, but these nets are connected differently, forming the Mo{sub 2}FeB{sub 2} crystal structure. A search of the literature revealed that compounds with the composition R{sub 2}XM{sub 2} (R=Sc, Y, Ti, Zr, Hf, rare earth; X=main group element; M=transition metal, Si, Ge) crystallize in one of four crystal structures: the Mo{sub 2}FeB{sub 2}, Zr{sub 3}Al{sub 2}, Mn{sub 2}AlB{sub 2} and W{sub 2}CoB{sub 2} crystal structures. These crystal structures are described, and the relationships between them are highlighted. Gd{sub 2}AlGe{sub 2} forms an entirely new crystal structure, and the details of its synthesis and characterization are given. Electronic structure calculations are performed to understand the nature of bonding in this compound and how electrons can be accounted for. A series of electronic structure calculations were performed on models with the U{sub 3}Si{sub 2} and Zr{sub 3}Al{sub 2} structures, using Zr and A1 as the building blocks. The starting point for these models was the U{sub 3}Si{sub 2} structure, and models were created to simulate the transition from the idealized U{sub 3}Si{sub 2} structure to the distorted Zr{sub 3}Al{sub 2} structure. Analysis of the band structures of the models has shown that the transition from the U{sub 3}Si{sub 2} structure to the Zr{sub 3}Al{sub 2} structure lifts degeneracies along the {Lambda} {yields} Z direction, indicating a Peierls-type mechanism for the displacement occurring in the positions of the Zr atoms.

Sean William McWhorter

2006-05-01T23:59:59.000Z

22

E-Print Network 3.0 - al hf ta Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

a JEOL electron microprobe and Ca, Ti, Nb, Ta, Hf and Zr abundances measured using laser ablation... for an Al-rich chon- drule. As Figure 1 shows there is little evidence for...

23

Growth, microstructure and electrical properties of sputter-deposited hafnium oxide (HfO2) thin films grown using HfO2 ceramic target  

SciTech Connect

Hafnium oxide (HfO?) thin films have been made by radio-frequency (rf) magnetron-sputtering onto Si(100) substrates under varying growth temperature (Ts). HfO? ceramic target has been employed for sputtering while varying the Ts from room temperature to 500?C during deposition. The effect of Ts on the growth and microstructure of deposited HfO? films has been studied using grazing incidence x-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), and high-resolution scanning electron microscopy (HR-SEM) coupled with energy dispersive x-ray spectrometry (EDS). The results indicate that the effect of Ts is significant on the growth, surface and interface structure, morphology and chemical composition of the HfO? films. Structural characterization indicates that the HfO? films grown at Ts<200 ?C are amorphous while films grown at Ts>200 ?C are nanocrystalline. An amorphous-to-crystalline transition occurs at Ts=200 ?C. Nanocrystalline HfO? films crystallized in a monoclinic structure with a (-111) orientation. XPS measurements indicated the high surface-chemical quality and stoichiometric nature of the grown HfO? films. An interface layer (IL) formation occurs due to reaction at the HfO?-Si interface for HfO? films deposited at Ts>200 ?C. The thickness of IL increases with increasing Ts. XPS and EDS at the HfO?-Si cross-section indicate the IL is a (Hf, Si)-O compound. The electrical characterization using capacitance-voltage measurements indicate that the dielectric constant decreases from 25 to 16 with increasing Ts.

Aguirre, B.; Vemuri, R. S.; Zubia, David; Engelhard, Mark H.; Shutthanandan, V.; Kamala Bharathi, K.; Ramana, Chintalapalle V.

2011-01-01T23:59:59.000Z

24

Phase selection and transition in Hf-rich hafnia-titania nanolaminates  

SciTech Connect

Hf-rich hafnia-titania nanolaminate films with five HfO{sub 2}-TiO{sub 2} bilayer architectures (0.64 to 0.94 Hf atom fraction) were sputter deposited on unheated fused silica substrates, annealed post-deposition from 573 to 1273 K, and analyzed by x-ray diffraction to study phase selection and transition. Isochronal annealing for 1 h intervals from 573 to 1173 K produces weak crystallization into monoclinic (m) HfO{sub 2} doped with Ti, i.e., m-Hf{sub 1-x}Ti{sub x}O{sub 2}. The amount of Ti incorporated into m-HfO{sub 2} depends upon both architecture and overall stoichiometry, but in all but the coarsest architecture, exceeds the bulk solubility limit of x = 0.05. Initial annealing at 1273 K produces significant crystallization into a biphasic structure, m-Hf{sub 1-x}Ti{sub x}O{sub 2} and orthorhombic (o) HfTiO{sub 4}. From bulk phase equilibrium considerations, o-HfTiO{sub 4} is expected to crystallize under conditions of interfacial bilayer mixing. However, upon further annealing at 1273 K, o-HfTiO{sub 4} proves to be unstable. o-HfTiO{sub 4} demixing inevitably occurs independent of architecture and stoichiometry, resulting in final crystallization products after 96 h at 1273 K that are m-Hf{sub 1-x}Ti{sub x}O{sub 2} with x {approx_equal} 0.05 and TiO{sub 2} doped with Hf. We suggest that o-HfTiO{sub 4} instability arises from a driving force to form domains similar to those found in the low temperature in/commensurate structures of ZrTiO{sub 4}. A detailed crystallographic group-subgroup analysis of the o (Pbcn) {yields} m (P2{sub 1}/c) transition shows that these domains can be represented by an orientation twin in the latter structure and their creation can be achieved by a single step second-order phase transition.

Cisneros-Morales, Massiel Cristina; Rubin Aita, Carolyn

2011-06-15T23:59:59.000Z

25

Characterization of Ceramic Plasma-Sprayed Coatings, and Interaction Studies Between U-Zr Fuel and Ceramic Coated Interface at an Elevated Temperature  

SciTech Connect

Candidate coating materials for re-usable metallic nuclear fuel crucibles, HfN, TiC, ZrC, and Y2O3, were plasma-sprayed onto niobium substrates. The coating microstructure and the thermal cycling behavior were characterized, and U-Zr melt interaction studies carried out. The Y2O3 coating layer had a uniform thickness and was well consolidated with a few small pores scattered throughout. While the HfN coating was not well consolidated with a considerable amount of porosity, but showed somewhat uniform thickness. Thermal cycling tests on the HfN, TiC, ZrC, and Y2O3 coatings showed good cycling characteristics with no interconnected cracks forming even after 20 cycles. Interaction studies done on the coated samples by dipping into a U-20wt.%Zr melt indicated that HfN and Y2O3 did not form significant reaction layers between the melt and the coating while the TiC and the ZrC coatings were significantly degraded. Y2O3 exhibited the most promising performance among HfN, TiC, ZrC, and Y2O3 coatings.

Ki Hwan Kim; Chong Tak Lee; R. S. Fielding; J. R. Kennedy

2011-08-01T23:59:59.000Z

26

Rf Feedback free electron laser  

DOE Patents (OSTI)

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.

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

1981-01-01T23:59:59.000Z

27

Booster Subharmonic RF Capture Design  

NLE Websites -- All DOE Office Websites (Extended Search)

Booster Subharmonic RF Capture Design 1 Booster Subharmonic RF Capture Design Nicholas S. Sereno, 7102002 1.0 Motivation and Requirements Successful operation of the APS storage...

28

Spectroscopy of Rf257  

Science Journals Connector (OSTI)

The isotope Rf257 was produced in the fusion-evaporation reaction Pb208(Ti50,n)Rf257. Reaction products were separated and identified by mass. Delayed spectroscopy of Rf257 and its decay products was performed. A partial decay scheme with configuration assignments is proposed based on ? hindrance factors. The excitation energy of the 1/2+[620] configuration in No253 is proposed. The energy of this 1/2+ state in a series of N=151 isotones increases with nuclear charge, reflecting an increase in the N=152 gap. This gap is deduced to grow substantially from 850 to 1400 keV between Z=94 and 102. An isomeric state in Rf257, with a half-life of 160-31+42??s, was discovered by detecting internal conversion electrons followed by ? decay. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal conversion electrons, with a half-life of 4.1-1.3+2.4 s, followed by ? decay, was also observed. These events might originate from the decay of excited states in Lr257, populated by electron-capture decay of Rf257. Fission of Rf257 was unambiguously detected, with a branching ratio of bRfSF=0.020.01.

J. Qian; A. Heinz; T. L. Khoo; R. V. F. Janssens; D. Peterson; D. Seweryniak; I. Ahmad; M. Asai; B. B. Back; M. P. Carpenter; A. B. Garnsworthy; J. P. Greene; A. A. Hecht; C. L. Jiang; F. G. Kondev; T. Lauritsen; C. J. Lister; A. Robinson; G. Savard; R. Scott; R. Vondrasek; X. Wang; R. Winkler; S. Zhu

2009-06-22T23:59:59.000Z

29

Calculations of Hf -electron affinity and  

E-Print Network (OSTI)

Calculations of Hf - electron affinity and photodetachment partial cross sections Lin Pan. PHYS. B 2009 #12;Calculations of Hf - electron affinity and photodetachment partial cross sections 2 1 the replacements, the subshells that are not occupied in #12;Calculations of Hf - electron affinity

Beck, Donald R.

30

RF Interconnection and Switching  

Science Journals Connector (OSTI)

The components that connect, interface, transfer, and filter RF energy within a given systemor between systemsare critical elements in the operation of vacuum tube devices. Such hardware, usually passive, de...

Jerry C. Whitaker

1994-01-01T23:59:59.000Z

31

ISG8-RF Sources  

NLE Websites -- All DOE Office Websites (Extended Search)

RF Sources - (WG3) RF Sources - (WG3) Orange Rm Yong Ho Chin, Christopher Nantista, and Sami G. Tantawi Parallel Sessions: Working Groups: WG1: Parameters, Design, Instrumentation and Tuning WG2: Damping Rings and ATF WG3: RF Sources WG4:Structures WG5: Ground Motion; Site Requirements and Investigations Monday Morning 9:00-10:30 Plenary Coffee Break 11:00-12:00 Planning Session. Monday Afternoon 13:30-15:30 High Gradient Issues (Joint with working group 4) Coffee Break 16:00-16:30 The 8-Pack Project -- D. Atkinson 16:30-17:30 High Gradient Issues and Discussions Continued. Tuesday Morning 9:30-10:30 Klystrons 9:30-10:00 Status of PPM Klystron Development for JLC -- Y. H. Chin 10:00-10:30 Design of 150MW Multi-Beam Klystron -- S. Matsumoto Coffee Break 11:00-11:30 Klystron Development at SLAC -- G. Caryotakis

32

Can RF help CMOS processors?  

E-Print Network (OSTI)

FOR C OMMUNICATIONS Can RF Help CMOS Processors? Eran SocherRF communication can help increase the wired communicationaluminum and low-K dielectrics help reduce wire delay but do

Socher, Eran; Chang, Mau-Chung Frank

2007-01-01T23:59:59.000Z

33

The ZR Refurbishment Project  

Science Journals Connector (OSTI)

ZR is a refurbished (R) version of Z aiming to improve its overall performance reliability precision pulse shape tailoring and reproducibility. Z the largest pulsed power machine at Sandia began in December 1985 as the Particle Beam Fusion Accelerator II (PBFA II). PBFA II was modified in 1996 to a z?pinch driver by incorporating a high?current (20?MA 2.5?MV) configuration in the inner ? 4.5 meter section. Following its remarkable success as z?pinch driver PBFA II was renamed Z in 1997. Currently Z fires 170 to 180 shots a year with a peak load current of the order of 1820 MA. The maximum z?pinch output achieved to date is 1.6?MJ 170?TW radiated energy and power from a single 4?cm diameter 2?cm tall array and 215 eV temperature from a dynamic hohlraum. ZR in turn will operating in double shift enable 400 shots per year deliver a peak current of 26 MA into a standard 4cm 2cm Z?pinch load and should provide a total radiated x?ray energy and power of 3 MJ and 350 TW respectively achieve a maximum hohlraum temperature of 260 eV and include a pulse?shaping flexibility extending from 100ns to 300ns for equation of state and isentropic compression studies. To achieve this performance ZR will incorporate substantial modifications and upgrades to Marx generator intermediate store capacitors gas and water switches water transmission lines and the laser triggering system. Test beds are already in place and the new pulsed power components are undergoing extensive evaluation. The Z refurbishment (ZR) will be operational by 2006 and will cost approximately $60M.

Dillon H. McDaniel; Michael G. Mazarakis; David E. Bliss; Juan M. Elizondo; Henry C. Harjes; Harry C. Ives III; David L. Kitterman; John E. Maenchen; Timothy D. Pointon; Stephen E. Rosenthal; David L. Smith; Kenneth W. Struve; William A. Stygar; Edward A. Weinbrecht; David L. Johnson; John P. Corley

2002-01-01T23:59:59.000Z

34

WAVE-DRIVEN SURFACE FROM HF RADAR  

E-Print Network (OSTI)

experiments using the University of Miami's Ocean Surface Current Radar (OSCR) (Shay et al., 1995, 1997 to the internal wave signals. Observations The HF radar system mapped the coastal ocean currents over a 30 ? 45 kmFEATURE INTERNAL CURRENTS WAVE-DRIVEN SURFACE FROM HF RADAR By Lynn K. Shay Observations from

Miami, University of

35

RF current sensor  

DOE Patents (OSTI)

An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

1998-11-10T23:59:59.000Z

36

EXPERIMENTAL STUDIES OF RF BREAKDOWNS IN THE COUPLER OF THE TTF RF GUN  

E-Print Network (OSTI)

EXPERIMENTAL STUDIES OF RF BREAKDOWNS IN THE COUPLER OF THE TTF RF GUN J.-P. Carneiro , S I, the RF gun of the TESLA Test Facility (TTF) has been operated with long RF pulses (up to 0.9 ms Fermilab has developed and delivered to DESY two RF guns for the operation of phase 1 of the TESLA Test

37

Acidizing of Sandstone Reservoirs Using HF and Organic Acids  

E-Print Network (OSTI)

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...

Yang, Fei

2012-10-19T23:59:59.000Z

38

Atomic scale observation of phase separation and formation of silicon clusters in Hf higk-{kappa} silicates  

SciTech Connect

Hafnium silicate films were fabricated by RF reactive magnetron sputtering technique. Fine microstructural analyses of the films were performed by means of high-resolution transmission electron microscopy and atom probe tomography. A thermal treatment of as-grown homogeneous films leads to a phase separation process. The formation of SiO{sub 2} and HfO{sub 2} phases as well as pure Si one was revealed. This latter was found to be amorphous Si nanoclusters, distributed uniformly in the film volume. Their mean diameter and density were estimated to be about 2.8 nm and (2.9 {+-} 0.4) x 10{sup 17} Si-ncs/cm{sup 3}, respectively. The mechanism of the decomposition process was proposed. The obtained results pave the way for future microelectronic and photonic applications of Hf-based high-{kappa} dielectrics with embedded Si nanoclusters.

Talbot, E.; Roussel, M.; Genevois, C.; Pareige, P. [Groupe de Physique des Materiaux (GPM), Universite et INSA de Rouen, UMR CNRS 6634, Av. de l'Universite, BP 12, 76801 Saint Etienne du Rouvray (France); Khomenkova, L.; Portier, X.; Gourbilleau, F. [Centre de Recherche sur les Ions, les Materiaux et la Photonique (CIMAP), CEA/CNRS/ENSICAEN/UCBN, 6 Bd. Marechal Juin, 14050 Caen Cedex 4 (France)

2012-05-15T23:59:59.000Z

39

Stellar (n,?) cross sections of Hf174 and radioactive Hf182  

Science Journals Connector (OSTI)

The stellar neutron capture cross sections of Hf174 and the radioactive isotope Hf182 (t1/2=8.9106 yr) have been measured for the first time at kT=25 keV by means of the activation technique. These isotopes originate from different stellar scenarios, Hf174 from the p-process by a series of photodisintegration reactions of heavier seed nuclei, and Hf182 from the s-process in asymptotic giant branch stars as well as from the r-process in supernovae or neutron star mergers. Both activation measurements were carried out at the Karlsruhe Van de Graaff accelerator using the Li7(p,n)Be7 reaction for simulating a Maxwellian neutron spectrum corresponding to a thermal energy of kT=25 keV. The Maxwellian averaged cross sections (MACS) extrapolated to the common s-process temperatures at kT=30 keV yield ???30=98346 and 1418 mb for Hf174 and Hf182, respectively.

C. Vockenhuber; I. Dillmann; M. Heil; F. Kppeler; N. Winckler; W. Kutschera; A. Wallner; M. Bichler; S. Dababneh; S. Bisterzo; R. Gallino

2007-01-12T23:59:59.000Z

40

Phase transformations in Cu-Zr multilayers  

SciTech Connect

A study of phase transformations is reported for Cu-rich, Cu-Zr multilayer foils synthesized using magnetron sputter deposition and annealed using a differential scanning calorimeter. The foils range in composition from 1.6 to 9.0 at% Zr and consist of alternate layers of polycrystalline Cu and Zr. Differential scanning calorimetry, X-ray analysis and electron microscopy were used to three distinct reactions in the foils: a mixing and an amorphization of the Cu and die Zr, a crystallization on of this amorphous phase to the metastable intermetallic Cu{sub 5l}Zr{sub l4}, and a transformation of the Cu{sub 5l}Zr{sub l4} phase into the equilibrium phase Cu{sub 9}Zr{sub 2}. The as-deposited layering remained stable during the first two reactions and then broke down in the third reaction as large grains of Cu{sub 9}Zr{sub 2} encompassed the smaller Cu grains. Heats of the reactions and activation energies of these reactions are measured and are compared to values reported for bulk samples. The measured heats provide evidence that amorphous Cu-Zr alloys phase separate and that mixing and short range ordering produce 3.5 times more heat than long range ordering produces when Ca and Zr react and form Cu{sub 5l}Zr{sub l4}.

Weihs, T.P.; Barbee, T.W. Jr.; Wall, M.A.

1993-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Cryogenic vacuumm RF feedthrough device  

DOE Patents (OSTI)

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.

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

2008-12-30T23:59:59.000Z

42

Note on RF Photo-Cathode Gun  

E-Print Network (OSTI)

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,

Kim, Kwang-Je

2010-01-01T23:59:59.000Z

43

Simulation of synchrotron motion with rf noise  

SciTech Connect

The theoretical formulation is described that is behind an algorithm for synchrotron phase-space tracking with rf noise and some preliminary simulation results of bunch diffusion under rf noise obtained by actual tracking.

Leemann, B.T.; Forest, E.; Chattopadhyay, S.

1986-08-01T23:59:59.000Z

44

Intelligent Radio Frequency (RF) Monitoring  

E-Print Network (OSTI)

? Intelligent Radio Frequency (RF) Monitoring ? 2009 Armstrong International, Inc. www.armstronginternational.com 2 ?Expect many enjoyable experiences!? David M. Armstrong Present Process Challenges ? Identifying a failure ? Procedure.... Armstrong Steam Trap Challenges ? Identifying a failure ? Manpower ? Location ? Magnitude of failure ? Energy loss ? Loss of heat transfer ? Justification for repair ? ?Speed of Implementation? ? Environmental concerns Manpower Location 4...

Kimbrough, B.

45

SPL RF Coupler Cooling Efficiency  

E-Print Network (OSTI)

Energy saving is an important challenge in accelerator design. In this framework, reduction of heat loads in a cryomodule is of fundamental importance due to the small thermodynamic efficiency of cooling at low temperatures. In particular, care must be taken during the design of its critical components (e.g. RF couplers, coldwarm transitions). In this framework, the main RF coupler of the Superconducting Proton Linac (SPL) cryomodule at CERN will not only be used for RF powering but also as the main mechanical support of the superconducting cavities. These two functions have to be accomplished while ensuring the lowest heat in-leak to the helium bath at 2 K. In the SPL design, the RF coupler outer conductor is composed of two walls and cooled by forced convection with helium gas at 4.5 K. Analytical, semi-analytical and numerical analyses are presented in order to defend the choice of gas cooling. Temperature profiles and thermal performance have been evaluated for different operating conditions; a sensitivit...

Bonomi, R; Montesinos, E; Parma, V; Vande Craen, A

2014-01-01T23:59:59.000Z

46

High-Power Rf Load  

DOE Patents (OSTI)

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.

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

1998-09-01T23:59:59.000Z

47

Electrooptic parameters of the hydrogen bridge in BHF complexes [B=HF, H2O, (CH3)2NCHO  

Science Journals Connector (OSTI)

The density-functional method [B3LYP/6-31++G(d,p)] is used to calculate molecular associates with various enthalpies of formation: HFHF, H2OHF, and...

Yukhnevich, G V; Tsoi, O Yu

2007-01-01T23:59:59.000Z

48

Josephson device with a matched rf source  

SciTech Connect

Analog simulation of a resistance-shunted ac Josephson junction coupled to an rf source with matching impedance reveals (1) added structure in the device's V-I curve even when the source is quiescent and (2) rf-induced steps with peak amplitudes between those produced by voltage and current rf sources. Both results are consistent with experimental data.

Longacre, A. Jr.

1980-03-01T23:59:59.000Z

49

Low jitter RF distribution system  

DOE Patents (OSTI)

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.

Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

2012-09-18T23:59:59.000Z

50

Single electron beam rf feedback free electron laser  

DOE Patents (OSTI)

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.

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

1981-02-11T23:59:59.000Z

51

Feedback control of HfO{sub 2} etch processing in inductively coupled Cl{sub 2}/N{sub 2}/Ar plasmas  

SciTech Connect

The etch rate of HfO{sub 2} etch processing has been feedback controlled in inductively coupled Cl{sub 2}/N{sub 2}/Ar plasmas. The ion current and the root mean square rf voltage on the wafer stage, which are measured using a commercial impedance meter connected to the wafer stage, are chosen as controlled variables because the positive-ion flux and ion energy incident upon the wafer surface are the key factors that determine the etch rate. Two 13.56 MHz rf generators are used to adjust the inductively coupled plasma power and bias power which control ion density and ion energy, respectively. The adopted HfO{sub 2} etch processing used rather low rf voltage. The ion-current value obtained by the power/voltage method is underestimated, so the neural-network model was developed to assist estimating the correct ion-current value. The experimental results show that the etch-rate variation of the closed-loop control is smaller than that of the open-loop control. However, the first wafer effect cannot be eliminated using closed-loop control and thus to achieve a constant etch rate, the chamber-conditioning procedure is required in this etch processing.

Lin Chaung; Leou, K.-C.; Li, T.-C.; Lee, L.-S.; Tzeng, P.-J. [Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan 30043 (China); Electronic Research and Service Organization, Industrial Technology Research Institute, Hsinchu, Taiwan 310 (China)

2008-09-15T23:59:59.000Z

52

C15 intermetallic compounds HfV{sub 2}+Nb  

SciTech Connect

Phase fields and equilibria in the Hf-V-Nb system were determined using a combination-of SEM, EDS and x-ray diffraction. The structural stability of the C15 HfV{sub 2+}Nb was studied by x-ray diffraction and specific heat measurements. The elastic constants of C15 HfV{sub 2+}Nb were measured by the resonant ultrasound spectroscopy technique. First-principle quantum mechanical calculations based on the local-density-functional theory have been employed to study the total energy and electronic structure of C15 HfV{sub 2}, which can be used to understand the physical and metallurgical properties of the C15 intermetallics HfV{sub 2+}Nb.

Chu, F.; Chen, S.P.; Mitchell, T.E. [Los Alamos National Lab., NM (United States); Pope, D.P. [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Materials Science and Engineering; Liu, C.T. [Oak Ridge National Lab., TN (United States)

1994-12-31T23:59:59.000Z

53

RF Systems in a Neutrino Factory  

SciTech Connect

Based on existing sources, I compile parameters for the RF systems for a neutrino factory which accelerates to 10 GeV.

Berg J. S.

2012-09-07T23:59:59.000Z

54

RF Micro Devices | Open Energy Information  

Open Energy Info (EERE)

for Others) for this property. Partnering Center within NREL National Center for Photovoltaics Partnership Year 2009 RF Micro Devices is a company located in Greensboro, NC....

55

High voltage RF feedthrough bushing  

DOE Patents (OSTI)

Described is a multi-element, high voltage radio frequency bushing for trmitting RF energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

Grotz, Glenn F. (Huntington Station, NY)

1984-01-01T23:59:59.000Z

56

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

SciTech Connect

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.

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

2014-04-29T23:59:59.000Z

57

Note on RF Photo-Cathode Gun  

E-Print Network (OSTI)

E.R. Gray and P.M. Giles, "Photo-cathodes in AcceleratorProceedings Note on RF Photo-Cathode Gun K. -J. Kim August106 LBL-29538 Note on RF Photo-Cathode G un Kwang-Je Kim

Kim, Kwang-Je

2010-01-01T23:59:59.000Z

58

RF SYSTEM FOR THE SNS ACCUMULATOR RING.  

SciTech Connect

During accumulation the RF beam current in the spallation neutron source ring rises from 0 to 50 amperes. A clean, 250 nanosecond gap is needed for the extraction kicker risetime. Large momentum spread and small peak current are needed to prevent instabilities and stopband related losses. A robust RF system meeting these requirements has been designed.

BLASKIEWICZ, M.; BRENNAN, J.M.; BRODOWSKI, J.; DELONG, J.; METH, M.; SMITH, K.; ZALTSMAN, A.

2001-06-18T23:59:59.000Z

59

Plasma Edge Cooling during rf Heating  

Science Journals Connector (OSTI)

A new approach to prevent the influx of high-Z impurities into the core of a tokamak discharge by using rf power to modify the edge plasma temperature profile is discussed. This concept is based on spectroscopic measurements on PLT (Princeton Large Torus) during ohmic heating and ATC (Adiabatic Toroidal Compressor) during rf heating.

S. Suckewer and R. J. Hawryluk

1978-06-19T23:59:59.000Z

60

R&D ERL: Low level RF  

SciTech Connect

A superconducting RF (SRF) Energy Recovery Linac (ERL) is currently under development at the Collider-Accelerator Department (C-AD) at Brookhaven National Laboratory (BNL). The major components from an RF perspective are (a) a 5-cell SRF ERL cavity, (b) an SRF photocathode electron gun, and (c) a drive laser for the photocathode gun. Each of these RF subsystems has its own set of RF performance requirements, as well as common requirements for ensuring correct synchronism between them. A low level RF (LLRF) control system is currently under development, which seeks to leverage both technology and experience gained from the recently commissioned RHIC LLRF system upgrade. This note will review the LLRF system requirements and describe the system to be installed at the ERL.

Smith, K.

2010-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

RF Cavity Characterization with VORPAL  

SciTech Connect

When designing a radio frequency (RF) accelerating cavity structure various figures of merit are considered before coming to a final cavity design. These figures of merit include specific field and geometry based quantities such as the ratio of the shunt impedance to the quality factor (R/Q) or the normalized peak fields in the cavity. Other important measures of cavity performance include the peak surface fields as well as possible multipacting resonances in the cavity. High fidelity simulations of these structures can provide a good estimate of these important quantities before any cavity prototypes are built. We will present VORPAL simulations of a simple pillbox structure where these quantities can be calculated analytically and compare them to the results from the VORPAL simulations. We will then use VORPAL to calculate these figures of merit and potential multipacting resonances for two cavity designs under development at Jefferson National Lab for Project X.

C. Nieter, C. Roark, P. Stoltz, C.D. Zhou, F. Marhauser

2011-03-01T23:59:59.000Z

62

Theoretical Assessment of 178m2Hf De-Excitation  

SciTech Connect

This document contains a comprehensive literature review in support of the theoretical assessment of the {sup 178m2}Hf de-excitation, as well as a rigorous description of controlled energy release from an isomeric nuclear state.

Hartouni, E P; Chen, M; Descalle, M A; Escher, J E; Loshak, A; Navratil, P; Ormand, W E; Pruet, J; Thompson, I J; Wang, T F

2008-10-06T23:59:59.000Z

63

Growth of HfO{sub 2} films using an alternate reaction of HfCl{sub 4} and O{sub 2} under atmospheric pressure  

SciTech Connect

HfO{sub 2} films were deposited onto a Si(100) substrate using an alternate reaction of HfCl{sub 4} and O{sub 2} under atmospheric pressure. Self-limiting growth of the HfO{sub 2} was achieved in the range of the growth temperature above 873K. The X-ray diffraction of the HfO{sub 2} films showed a typical diffraction pattern assigned to the monoclinic polycrystalline phase. Residual chloride concentration in HfO{sub 2} films were not higher than 0.1at%. When the growth temperature was 973K, the HfSiO{sub x} is formed in HfO{sub 2} film. This gives effective permittivity value of 9.6 for the HfO{sub 2} film grown at 573K.

Takahashi, Naoyuki [Department of Materials Science and Technology, Faculty of Engineering Shizuoka University, 3-5-1 Johoku, Hamamatu, Shizuoka 432-8561 (Japan)]. E-mail: tntakah@ipc.shizuoka.ac.jp; Nonobe, Shinichi [Department of Materials Science and Technology, Faculty of Engineering Shizuoka University, 3-5-1 Johoku, Hamamatu, Shizuoka 432-8561 (Japan); Nakamura, Takato [Department of Materials Science and Technology, Faculty of Engineering Shizuoka University, 3-5-1 Johoku, Hamamatu, Shizuoka 432-8561 (Japan)

2004-11-01T23:59:59.000Z

64

Samsung: ENERGY STAR Referral (RF26VAB)  

Energy.gov (U.S. Department of Energy (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.

65

The Emergence of RF-Powered Computing  

Science Journals Connector (OSTI)

Extracting power "from thin air" has a quality of science fiction about it, yet technology trends make it likely that in the near future, small computers in urban areas will use ambient RF signals for both power and communication. The first Web extra ... Keywords: Backscatter,RF signals,Radio frequency,Computers,Telemetry,TV,Power distribution,Wireless communication,Ubiquitous computing,emerging technologies,wireless communication,ubiquitous computing

Shyamnath Gollakota, Matthew Reynolds, Joshua Smith, David Wetherall

2014-01-01T23:59:59.000Z

66

RF MEMS reconfigurable triangular patch antenna.  

SciTech Connect

A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

Christodoulou, Christos George (The University of New Mexico, Albuquerque, NM); Nordquist, Christopher Daniel; Feldner, Lucas Matthew

2005-07-01T23:59:59.000Z

67

RF MEMS reconfigurable triangular patch antenna.  

SciTech Connect

A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

Nordquist, Christopher Daniel; Christodoulou, Christos George (University of New Mexico, Albuquerque, NM); Feldner, Lucas Matthew

2005-01-01T23:59:59.000Z

68

Superlattice Structure and Precipitates in O+ and Zr+ Ion Coimplanted...  

NLE Websites -- All DOE Office Websites (Extended Search)

and Zr+ Ion Coimplanted SrTiO3: a Model Waste Form for 90Sr. Abstract: We investigate strontium titanate as a model waste form for 90Sr. Implantation with O+ and Zr+ ions, followed...

69

Growth mechanism difference of sputtered HfO{sub 2} on Ge and on Si  

SciTech Connect

HfO{sub 2} films were deposited by the reactive sputtering on Ge and Si substrates simultaneously, and we found both the interface layer and the HfO{sub 2} film were thinner on Ge substrate than those on Si substrate. A metallic Hf layer has a crucial role for the thickness differences of both interface layer and HfO{sub 2} film, since those thickness differences were observed only when an ultrathin metallic Hf layer was predeposited before the reactive sputtering process. The role of metallic Hf in these phenomena is understandable by assuming the formation of a volatile Hf-Ge-O ternary compound at the early stage of the film growth. This result shows that the HfO{sub 2}/Ge system has an advantage over the HfO{sub 2}/Si system from the viewpoint of further reduction of the gate oxide film thickness.

Kita, Koji; Kyuno, Kentaro; Toriumi, Akira [Department of Materials Science, School of Engineering, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2004-07-05T23:59:59.000Z

70

Early (4.5 Ga) formation of terrestrial crust: LuHf, 18 thermometry results for Hadean zircons  

E-Print Network (OSTI)

the characterization of 176 Hf/177 Hf initial ratios (Hf ) in Hadean zircons by acquiring a further 116 laser ablationEarly (4.5 Ga) formation of terrestrial crust: Lu­Hf, 18 O, and Ti thermometry results for Hadean Editor: R.W. Carlson Available online 19 February 2008 Abstract Large deviations in Hf(T) from bulk

Harrison, Mark

71

Determination of dynamic fracture parameters for HF?1 steel  

Science Journals Connector (OSTI)

Dynamic fracture parameters have been determined for two heat treatments of HF?1 steel. A gas gun was used for the experiments. Different amounts of fracture damage were produced in HF?1 steel specimens under known impact conditions. The specimens were soft recovered sectioned and polished to reveal any internal microscopic fracture. The fracturecracks were then digitized. The velocities of the 1.15? 1.59? and 2.37?mm?thick impactor disks range from 0.120 to 0.276 km/s. The specimen disks were 3.18? and 6.35?mm thick. An SRI stress wave propagationcomputer program with a brittlefracturemodel was used for calculating the dynamic fracture parameters. A series of Hugoniot experiments was performed for HF?1 steel to determine equation of state input data for the computer program. The Hugoniot elastic limits were 2.2 and 2.4 GPa for the two heat treatments.

Willis Mock Jr.; William H. Holt

1982-01-01T23:59:59.000Z

72

RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES  

SciTech Connect

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.

Johnson, Rolland

2014-09-21T23:59:59.000Z

73

Electrochemical Conversion of Oxide Precursors to Consolidated Zr and Zr?2.5Nb Tubes  

Science Journals Connector (OSTI)

Electrochemical Conversion of Oxide Precursors to Consolidated Zr and Zr?2.5Nb ... Electrochemical reduction of tubular oxide precursors in molten calcium chloride and the subsequent in situ consolidation induced by electro-deoxygenation promise a low energy and fast route for manufacturing of zirconium-alloy-based artifacts, such as the nuclear fuel cladding tubes. ... Zircaloy) in a mold of Plaster of Paris. ...

Junjun Peng; Kai Jiang; Wei Xiao; Dihua Wang; Xianbo Jin; George Z. Chen

2008-11-11T23:59:59.000Z

74

Status of the ADMX and ADMX-HF experiments  

E-Print Network (OSTI)

The Axion Dark Matter eXperiment (ADMX) is in the midst of an upgrade to reduce its system noise temperature. ADMX-HF (High Frequency) is a second platform specifically designed for higher mass axions and will serve as an innovation test-bed. Both will be commissioning in 2013 and taking data shortly thereafter. The principle of the experiment, current experimental limits and the status of the ADMX/ADMX-HF program will be described. R&D on hybrid superconducting cavities will be discussed as one example of an innovation to greatly enhance sensitivity.

Karl van Bibber; Gianpaolo Carosi

2013-04-29T23:59:59.000Z

75

Status of the ADMX and ADMX-HF experiments  

E-Print Network (OSTI)

The Axion Dark Matter eXperiment (ADMX) is in the midst of an upgrade to reduce its system noise temperature. ADMX-HF (High Frequency) is a second platform specifically designed for higher mass axions and will serve as an innovation test-bed. Both will be commissioning in 2013 and taking data shortly thereafter. The principle of the experiment, current experimental limits and the status of the ADMX/ADMX-HF program will be described. R&D on hybrid superconducting cavities will be discussed as one example of an innovation to greatly enhance sensitivity.

van Bibber, Karl

2013-01-01T23:59:59.000Z

76

Rf capacitively-coupled electrodeless light source  

DOE Patents (OSTI)

An rf capacitively-coupled electrodeless light source is provided. The light source comprises a hollow, elongated chamber and at least one center conductor disposed within the hollow, elongated chamber. A portion of each center conductor extends beyond the hollow, elongated chamber. At least one gas capable of forming an electronically excited molecular state is contained within each center conductor. An electrical coupler is positioned concentric to the hollow, elongated chamber and the electrical coupler surrounds the portion of each center conductor that extends beyond the hollow, elongated chamber. A rf-power supply is positioned in an operable relationship to the electrical coupler and an impedance matching network is positioned in an operable relationship to the rf power supply and the electrical coupler.

Manos, Dennis M. (Williamsburg, VA); Diggs, Jessie (Norfolk, VA); Ametepe, Joseph D. (Roanoke, VA); Fugitt, Jock A. (Livingston, TX)

2000-01-01T23:59:59.000Z

77

X-Band RF Gun Development  

SciTech Connect

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.

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

2012-06-22T23:59:59.000Z

78

Oscillator strengths for Zr I and Zr II and a new determination of the solar abundance of zirconium  

SciTech Connect

A new determination of the solar abundance of zirconium has been made using equivalent-width data measured on the Jungfraujoch solar atlas together with new oscillator strengths derived from measurements of atomic lifetimes and branching ratios for 34 lines of Zr I and 24 lines of Zr II. Excellent agreement is found between the results derived from Zr I and Zr II lines and also with recent meteoritic results. The mean abundance of zirconium in the Sun is found to be A/sub Zr/ = 2.56 +- 0.05.

Biemont, E.; Grevesse, N.; Hannaford, P.; Lowe, R.M.

1981-09-01T23:59:59.000Z

79

Effect of Al addition on the microstructure and electronic structure of HfO2 film  

E-Print Network (OSTI)

Effect of Al addition on the microstructure and electronic structure of HfO2 film X. F. Wang investigated the microstructures and electronic structures of a series of hafnium aluminate HfAlO films with Al concentration ranging from 0% to 100%. When the films evolve from pure HfO2 to pure Al2O3 by increasing

Gong, Xingao

80

A day in the life of the RF spectrum  

E-Print Network (OSTI)

There is a misguided perception that RF spectrum space is fully allocated and fully used though even a superficial study of actual spectrum usage by measuring local RF energy shows it largely empty of radiation. Traditional ...

Cooley, James E. (James Edward)

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Novel rf mems tunable filters with adjustable spurious suppression  

E-Print Network (OSTI)

This thesis presents the theory and design of fixed and Radio Frequency (RF) Microelectromechanical Systems (MEMS) -based tunable microwave filters for RF and microwave applications. The methodology for the design of coupled resonator filters...

Sekar, Vikram

2009-05-15T23:59:59.000Z

82

RF Design of the LCLS Gun  

SciTech Connect

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.

Limborg-Deprey, C

2010-12-13T23:59:59.000Z

83

Fabrication of Niobium sheet for RF cavities  

E-Print Network (OSTI)

..................................................................................... 18 2 Fabrication of Niobium SRF Cavities............................................. 20 3 Fine Grain Cavities versus Single Crystal and Large Grain........... Cavities... typical to that of RF cavities in comparison with Cu at 77 and 300K. Nb has low surface resistance in the operating range of 1GHz among the metals. [27]. 2. Fabrication of Niobium SRF Cavities There are different approaches involved in making...

Balachandran, Shreyas

2009-05-15T23:59:59.000Z

84

Spontaneous fission properties of Rf104262  

Science Journals Connector (OSTI)

We have measured the mass and kinetic-energy distributions of fragments from the spontaneous fission (SF) of Rf104262. The Rf104262 was produced via the Pu244(22Ne,4n) reaction with a production cross section of ?0.7 nb using 114.4-MeV projectiles. The kinetic energies and times of the coincident fission fragments were measured using our rotating wheel system. From these data the half-life, mass, and kinetic-energy distributions were derived. The total kinetic-energy (TKE) distribution appears to consist of a single component with a most probable pre-neutron-emission TKE of 2152 MeV. The mass distribution is symmetric with a full width at half maximum of about 22 mass numbers. These results are consistent with trends observed for other trans-berkelium spontaneously fissioning isotopes. We determined the half-life to be 2.10.2 s by measuring its spontaneous fission decay. We also attempted to observe the alpha decay of Rf104262 by searching for alpha decay correlated in time with SF from the alpha daughter, 1.2-ms No258. We observed no such decays and have set an upper limit of 0.8% (68% confidence level) on the alpha decay branch of Rf104262. 1996 The American Physical Society.

M. R. Lane; K. E. Gregorich; D. M. Lee; M. F. Mohar; M. Hsu; C. D. Kacher; B. Kadkhodayan; M. P. Neu; N. J. Stoyer; E. R. Sylwester; J. C. Yang; D. C. Hoffman

1996-06-01T23:59:59.000Z

85

Configurations for short period rf undulators  

Several configurations for rf undulators energized at millimeter wavelengths and designed to produce coherent nanometer radiation from sub-GeV electron beams are analyzed and compared with one another. These configurations include a traveling-wave resonant ring, a standing wave resonator, and a resonator operating close to cutoff.

Kuzikov, S. V.; Jiang, Y.; Marshall, T. C.; Sotnikov, G. V.; Hirshfield, J. L.

2013-07-01T23:59:59.000Z

86

Rf beam control for the AGS Booster  

SciTech Connect

RF beam control systems for hadron synchrotrons have evolved over the past three decades into an essentially standard design. The key difference between hadron and lepton machines is the absence of radiation damping and existence of significant frequency variation in the case of hadrons. Although the motion of the hadron in the potential well of the rf wave is inherently stable it is not strongly damped. Damping must be provided by electronic feedback through the accelerating system. This feedback is typically called the phase loop. The technology of the rf beam control system for the AGS Booster synchrotron is described. First, the overall philosophy of the design is explained in terms of a conventional servo system that regulates the beam horizontal position in the vacuum chamber. The concept of beam transfer functions is fundamental to the mathematics of the design process and is reviewed. The beam transfer functions required for this design are derived from first principles. An overview of the beam signal pick-ups and high level rf equipment is given. The major subsystems, the frequency program, the heterodyne system, and beam feedback loops, are described in detail. Beyond accelerating the beam, the rf system must also synchronize the bunches in the Booster to the buckets in the AGS before transfer. The technical challenge in this process is heightened by the need to accomplish synchronization while the frequency is still changing. Details of the synchronization system are given. This report is intended to serve two purposes. One is to document the hardware and performance of the systems that have been built. The other is to serve as a tutorial vehicle from which the non-expert can not only learn the details of this system but also learn the principles of beam control that have led to the particular design choices made.

Brennan, J.M.

1994-09-26T23:59:59.000Z

87

Copper diffusion in single-crystal ?-Zr  

Science Journals Connector (OSTI)

Tracer diffusion of Cu64 in ?-Zr single crystals has been measured in the temperature range (615-860)C. The temperature dependences of the Cu64 diffusion coefficients in directions parallel to and perpendicular to the c axis are given by D?=0.40e-1.54 eVkT and D?=0.25e-1.60 eVkT cm2/sec, respectively. The results are discussed in terms of an interstitial diffusion mechanism.

G. M. Hood and R. J. Schultz

1975-05-15T23:59:59.000Z

88

Bond formation at the Ni/ZrO2 interface  

Science Journals Connector (OSTI)

We report on the formation of strong chemical bonds at the Ni(100)/cubic-ZrO2(100) polar interfaces. Ab initio density functional theory calculations demonstrate that both Zr/Ni and O/Ni junctions are energetically stable, and predict that two different interactions determine the interface adhesion. Our results reveal that O-Ni ionic bonds are formed by Ni electron donation, while the Zr-Ni bonds show a mixed character with ionic and electron hybridization contributions.

J. I. Beltrn; S. Gallego; J. Cerd; J. S. Moya; M. C. Muoz

2003-08-07T23:59:59.000Z

89

Intrinsic metastability of orthorhombic HfTiO{sub 4} in thin film hafnia-titania  

SciTech Connect

Orthorhombic (o) HfTiO{sub 4} is crystallized when sputter deposited hafnia-titania nanolaminates with ultrathin layers and bilayer (HfO{sub 2}){sub 0.5}(TiO{sub 2}){sub 0.5} composition are annealed between 573 and 1173 K. However, o-HfTiO{sub 4} demixes after annealing at 1273 K, a result not predicted from bulk thermodynamics. X-ray diffraction and Raman microscopy are used here to study structural changes as o-HfTiO{sub 4} demixes upon long-term annealing at 1273 K into Ti-doped monoclinic HfO{sub 2} and Hf-doped rutile TiO{sub 2}. We conclude that o-HfTiO{sub 4} crystallized at low temperature is intrinsically metastable. A space group symmetry analysis shows that demixing can be accomplished by a continuous phase transition chain.

Cisneros-Morales, Massiel Cristina; Aita, Carolyn Rubin [Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201 (United States)

2011-01-31T23:59:59.000Z

90

Comparison of the Ca+HF(DF) and Sr+HF(DF) reaction dynamics Rong Zhang, David J. Rakestraw,a) Kenneth G. McKendrick,b) and Richard N. Zare  

E-Print Network (OSTI)

Comparison of the Ca+HF(DF) and Sr+HF(DF) reaction dynamics Rong Zhang, David J. Rakestraw family, Ca and Sr with rovibrationally selected HF or DF, has been carried out under single-collision conditions. A thermal beam of the alkaline earth atoms, Ca or Sr, is fired into a low-pressure gas of HF

Zare, Richard N.

91

Use of GPS network data for HF Doppler measurements interpretation  

E-Print Network (OSTI)

The method of measurement of Doppler frequency shift of ionospheric signal - HF Doppler technique - is one of well-known and widely used methods of ionosphere research. It allows to research various disturbances in the ionosphere. There are some sources of disturbances in the ionosphere. These are geomagnetic storms, solar flashes, metrological effects, atmospheric waves. This method allows to find out the influence of earthquakes, explosions and other processes on the ionosphere, which occur near to the Earth. HF Doppler technique has the high sensitivity to small frequency variations and the high time resolution, but interpretation of results is difficult. In this work we make an attempt to use GPS data for Doppler measurements interpretation. Modeling of Doppler frequency shift variations with use of TEC allows to separate ionosphere disturbances of medium scale.

Petrova, Inna R; Latypov, Ruslan R

2014-01-01T23:59:59.000Z

92

CMS HF calorimeter PMTs and Xi(c)+ lifetime measurement  

SciTech Connect

This thesis consists of two parts: In the first part we describe the Photomultiplier Tube (PMT) selection and testing processes for the Hadronic Forward (HF) calorimeter of the CMS, a Large Hadron Collier (LHC) experiment at CERN. We report the evaluation process of the candidate PMTs from three different manufacturers, the complete tests performed on the 2300 Hamamatsu PMTs which will be used in the HF calorimeter, and the details of the PMT Test Station that is in University of Iowa CMS Laboratories. In the second part we report the {Xi}{sub c}{sup +} lifetime measurement from SELEX, the charm hadro-production experiment at Fermilab. Based upon 301 {+-} 31 events from three di.erent decay channels, by using the binned maximum likelihood technique, we observe the lifetime of {Xi}{sub c}{sup +} as 427 {+-} 31 {+-} 13 fs.

Akgun, Ugur; /Iowa U.

2003-12-01T23:59:59.000Z

93

ILC RF System R and D  

SciTech Connect

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.

Adolphsen, Chris; /SLAC

2012-07-03T23:59:59.000Z

94

The new RF sources for accelerators  

SciTech Connect

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.

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)

2012-12-21T23:59:59.000Z

95

Safety assessment for the rf Test Facility  

SciTech Connect

The Radio Frequency Test Facility (RFTF) is a part of the Magnetic Fusion Program's rf Heating Experiments. The goal of the Magnetic Fusion Program (MFP) is to develop and demonstrate the practical application of fusion. RFTF is an experimental device which will provide an essential link in the research effort aiming at the realization of fusion power. This report was compiled as a summary of the analysis done to ensure the safe operation of RFTF.

Nagy, A.; Beane, F. (eds.)

1984-08-01T23:59:59.000Z

96

Radio frequency (RF) heated supersonic flow laboratory  

SciTech Connect

A unique supersonic flow apparatus which employs an inductively-coupled, radio frequency (RF) torch to supply high enthalpy source gas to the nozzle inlet is described. The main features of this system are the plasma tube, a cooled nozzle assembly, and a combustion/expansion chamber with a heat exchanger. A description of these components with current test data is presented. In addition, a discussion of anticipated experiments utilizing this system is included.

Wantuck, P.; Watanabe, H.

1990-01-01T23:59:59.000Z

97

Superconducting RF systems for eRHIC  

SciTech Connect

The proposed electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron Energy Recovery Linac (ERL) and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.

Belomestnykh S.; Ben-Zvi, I.; Brutus, J.C.; Hahn, H. et al

2012-05-20T23:59:59.000Z

98

Experimental and theoretical study of the (n,2n) reaction on 174,176Hf isotopes  

Science Journals Connector (OSTI)

Cross sections for the 174Hf(n,2n)173Hf and 176Hf(n,2n)175Hf reactions have been measured on the 5.5-MV Van de Graaff tandem accelerator of National Centre for Scientific Research Demokritos in Athens, in the neutron energy region from 8.8 to 11.0 MeV, using the activation technique. An experimental method to account for the contamination of the 176Hf(n,2n) reaction by the 174Hf(n,?) reaction activated by the parasitic neutrons of the beam is presented. Statistical model calculations have also been performed using the nuclear-reaction codes empire-ii and talys. The results and effects of the nuclear input parameters as well as pre-equilibrium emission are discussed in detail.

M. Serris; M. Diakaki; S. Galanopoulos; M. Kokkoris; M. Lamprou; C. T. Papadopoulos; R. Vlastou; P. Demetriou; C. A. Kalfas; A. Lagoyannis

2012-09-07T23:59:59.000Z

99

A STATE VARIABLE DESCRIPTION OF THE RHIC RF CONTROL LOOPS.  

SciTech Connect

The beam transfer function changes during the RHIC ramp. The response of the RF control loops changes as a result. A state-variable description of the beam and the RF control loops was developed. This description was used to generate a set of feedback matrices that keeps the response of the RF control loops constant during the ramp. This paper describes the state-variable description and its use in determining the K matrices.

SCHULTHEISS,C.; BRENNAN,J.M.

2002-06-02T23:59:59.000Z

100

Crystal phase transition of HfO2 films evaporated by plasma-ion-assisted deposition  

Science Journals Connector (OSTI)

HfO2 is a well-known high-refractive-index material for optical interference coatings from the infrared down to the ultraviolet

Wang, Jue; Maier, Robert L; Schreiber, Horst

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Crystal Phase Transition of HfO2 Films Evaporated by Plasma Ion-Assisted Deposition  

Science Journals Connector (OSTI)

HfO2 films were evaluated by spectroscopic ellipsometry, indicating crystal phase transition due to plasma ion momentum transfer during deposition. The film inhomogeneity,...

Wang, Jue; Maier, Robert L; Schreiber, Horst

102

Reduced-temperature processing and consolidation of ultra-refractory Ta4HfC5  

SciTech Connect

TaC, HfC, and WC powders were subjected to high-energy milling and hot pressing to produce Ta4HfC5, a composite of Ta(4)HfC5 + 30 vol.% WC, and a composite of Ta4HfC5 + 50 vol.% WC. Sub-micron powders were examined after four different milling intervals prior to hot pressing. XRD was used to verify proper phase formation. SEM, relative density, and hardness measurements were used to examine the resulting phases. Hot pressed compacts of Ta4HfC5 showed densification as high as 98.6% along with Vickers hardness values of 21.4 GPa. Similarly, Ta4HfC5 + 30 vol.% WC exhibited 99% densification with a Vickers hardness of 22.5 GPa. These levels of densification were achieved at 1500 degrees C, which is lower than any previously reported sintering temperature for Ta4HfC5. Microhardness values measured in this study were higher than those previously reported for Ta4HfC5. The WC additions to Ta4HfC5 were found to improve densification and increase microhardness. (C) 2013 Elsevier Ltd. All rights reserved.

Gaballa, Osama [Ames Laboratory; Cook, B. A. [TRI International; Russell, A. M. [Ames Laboratory

2013-04-26T23:59:59.000Z

103

Active high-power RF switch and pulse compression system  

DOE Patents (OSTI)

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.

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

1998-01-01T23:59:59.000Z

104

ccsd00001055 First principles study of the solubility of Zr in Al  

E-Print Network (OSTI)

ccsd­00001055 (version 1) : 22 Jan 2004 First principles study of the solubility of Zr in Al (Dated: January 22, 2004) The experimental solubility limit of Zr in Al is well-known. Al3Zr has a stable the solubility limit of Zr in Al for the stable as well as the metastable phase diagrams. The formation energies

105

Investigation of abnormal negative threshold voltage shift under positive bias stress in input/output n-channel metal-oxide-semiconductor field-effect transistors with TiN/HfO{sub 2} structure using fast I-V measurement  

SciTech Connect

This letter investigates abnormal negative threshold voltage shifts under positive bias stress in input/output (I/O) TiN/HfO{sub 2} n-channel metal-oxide-semiconductor field-effect transistors using fast I-V measurement. This phenomenon is attributed to a reversible charge/discharge effect in pre-existing bulk traps. Moreover, in standard performance devices, threshold-voltage (V{sub t}) shifts positively during fast I-V double sweep measurement. However, in I/O devices, V{sub t} shifts negatively since electrons escape from bulk traps to metal gate rather than channel electrons injecting to bulk traps. Consequently, decreasing pre-existing bulk traps in I/O devices, which can be achieved by adopting Hf{sub x}Zr{sub 1?x}O{sub 2} as gate oxide, can reduce the charge/discharge effect.

Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen [Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang@mail.phys.nsysu.edu.tw; Lu, Ying-Hsin; Tsai, Jyun-Yu; Liu, Kuan-Ju [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Cheng, Osbert; Huang, Cheng-Tung; Lu, Ching-Sen [Device Department, United Microelectronics Corporation, Tainan Science Park, Taiwan (China)

2014-03-17T23:59:59.000Z

106

Interactions of oxygen with Zr(0001)  

SciTech Connect

Interaction of oxygen with Zr(0001) have been studied using low energy electron diffraction (LEED), work function ([Delta][phi]), static and dynamic secondary ion mass spectrometry (SSIMS, DSIMS), thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES) and nuclear reaction analysis (NRA). The initial sticking coefficient of oxygen is close to unity up to [approximately]0.75 ML at 90, 293 and 473 K. Oxygen chemisorption is disordered at room temperature and below. Heating the disordered surface to [approximately]473 K causes all oxygen to move to subsurface sites. A (1x2) ordered oxygen underlayer is formed consisting of three rotated domains of (1x2) superstructure with the oxygen atoms located between the first and second planes of zirconium atoms. This structure is stable up to about 573 K, above which temperature oxygen diffuses into the bulk. AES measurements employing oxide and metal signals were used to model the growth of oxide which was found to be temperature dependent. Both NRA and AES indicate linear oxygen uptake kinetics at 90 K with abrupt passivation as the limiting thickness is reached. SSIMS ion yield data taken during the oxidation of Zr(0001) at 90, 293 and 473 K was interpretable in the context of the oxygen coverage. Dissolution into the bulk of the saturated oxide layer grown at 90 K appears to occur by an island-type mechanism rather than layer-by-layer dissolution from the oxide-metal interface. Large [Delta][phi] changes that occur upon oxidation at 90 K and temperature ramping of the saturated oxide to 300 K are attributable to reversible molecular oxygen adsorption on the oxide. The diffusion of oxygen normal to the [0001] plane of zirconium has been measured by AES: D[sub 0] = (4.14.[+-]1.92) x 10[sup [minus]2] cm[sup [minus]2] s[sup [minus]1] and E[sub a]= 199.1 [+-]2.6 kJ mol[sup [minus]1]. The fundamental vibrational frequency for the [alpha]-Zr lattice was calculated to be (6.3 [+-] 2.9) x 10[sup 13]s[sup [minus]1].

Flinn, B.J.

1992-01-01T23:59:59.000Z

107

Extremely high frequency RF effects on electronics.  

SciTech Connect

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.

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

2012-01-01T23:59:59.000Z

108

The mechanism of HF formation in LiPF6 based organic carbonate electrolytes  

NLE Websites -- All DOE Office Websites (Extended Search)

The mechanism of HF formation in LiPF6 based organic carbonate electrolytes The mechanism of HF formation in LiPF6 based organic carbonate electrolytes Title The mechanism of HF formation in LiPF6 based organic carbonate electrolytes Publication Type Journal Article Year of Publication 2012 Authors Lux, Simon F., Ivan T. Lucas, Elad Pollak, Stefano Passerini, Martin Winter, and Robert Kostecki Journal Electrochemistry Communications Volume 14 Start Page 47 Issue 1 Pagination 47-50 Date Published 01/2012 Keywords Hydrofluoric acid, LiPF6 degradation, Lithium ion batteries, spectroscopic ellipsometry Abstract Spectroscopic ellipsometry was used to study the time-dependent formation of HF upon the thermal degradation of LiPF6 at 50 °C in a lithium ion battery electrolyte containing ethylene carbonate and diethyl carbonate. The generated HF was monitored by following the etching rate of a 300 nm thick SiO2 layer, grown on both sides of a silicon wafer substrate, as a function of the immersion time in the electrolyte at 50 °C. It was found that the formation of HF starts after 70 h of exposure time and occurs following several different phases. The amount of generated HF was calculated using an empirical formula correlating the etching rate to the temperature. Combining the results of the HF formation with literature data, a simplified mechanism for the formation of the HF involving LiPF6 degradation, and a simplified catalytical reaction pathway of the formed HF and silicon dioxide are proposed to describe the kinetics of HF formation.

109

Understanding Humic Acid / Zr(IV) Interaction - A Spectromicroscopy Approach  

SciTech Connect

Complexation of Zr(IV) by humic acid (HA) and polyacrylic acid (PAA) is investigated from the point of view of the organic ligand. STXM Spectromicroscopy and C 1s-NEXAFS point to different interaction mechanisms between Zr(IV) cations and oxo/hydroxo colloids and PAA. Under conditions where the metal aquo ion is stable, strong complexes are formed. In contrast, unspecific surface coating is identified when PAA is contacted with Zr(IV) oxo/hydroxide colloids. HA exhibits similar C 1s-NEXAFS features indicating a complexation reaction.

Rothe, Joerg; Plaschke, Markus; Denecke, Melissa A. [Forschungszentrum Karlsruhe, Institut fuer Nukleare Entsorgung, P.O. Box 3640, D-76021 Karlsruhe (Germany)

2007-02-02T23:59:59.000Z

110

Hydrogen production by steam reforming of LNG over Ni/Al2O3-ZrO2 catalysts: Effect of ZrO2 and preparation method of Al2O3-ZrO2  

Science Journals Connector (OSTI)

An Al2O3-ZrO2 support was prepared by grafting a zirconium precursor onto the surface of commercial ?-Al2O3. A physical mixture of Al2O3-ZrO2 was also prepared for the purpose of comparison. Ni/Al2O3-ZrO2 catalys...

Jeong Gil Seo; Min Hye Youn; Sunyoung Park

2008-01-01T23:59:59.000Z

111

Booster Synchrotron RF System Upgrade for SPEAR3  

SciTech Connect

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.

Park, Sanghyun; /SLAC; Corbett, Jeff; /SLAC

2012-07-06T23:59:59.000Z

112

RF cavity using liquid dielectric for tuning and cooling  

DOE Patents (OSTI)

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.

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

2012-04-17T23:59:59.000Z

113

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

E-Print Network (OSTI)

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

Kirkwood, Sheila

114

Interfacial and structural properties of sputtered HfO{sub 2} layers  

SciTech Connect

Magnetron sputtered HfO{sub 2} layers formed on a heated Si substrate were studied by spectroscopic ellipsometer (SE), x-ray diffraction (XRD), Fourier transform infrared (FTIR), and x-ray photoelectron spectroscopy (XPS) depth profiling techniques. The results show that the formation of a SiO{sub x} suboxide layer at the HfO{sub 2}/Si interface is unavoidable. The HfO{sub 2} thickness and suboxide formation are highly affected by the growth parameters such as sputtering power, O{sub 2}/Ar gas ratio during sputtering, sputtering time, and substrate temperature. XRD spectra show that the deposited film has (111) monoclinic phase of HfO{sub 2}, which is also supported by FTIR spectra. The atomic concentration and chemical environment of Si, Hf, and O have been measured as a function of depth starting from the surface of the sample by XPS technique. It shows that HfO{sub 2} layers of a few nanometers are formed at the top surface. Below this thin layer, Si-Si bonds are detected just before the Si suboxide layer, and then the Si substrate is reached during the depth profiling by XPS. It is clearly understood that the highly reactive sputtered Hf atoms consume some of the oxygen atoms from the underlying SiO{sub 2} to form HfO{sub 2}, leaving Si-Si bonds behind.

Aygun, G. [Department of Physics, Izmir Institute of Technology, Urla, TR-35430 Izmir (Turkey); Yildiz, I. [Department of Physics, Middle East Technical University, TR-06531 Ankara (Turkey); Central Laboratory, Middle East Technical University, TR-06531 Ankara (Turkey)

2009-07-01T23:59:59.000Z

115

Ca+HF: The anatomy of a chemical insertion reaction R. L. Jaffe  

E-Print Network (OSTI)

Ca+HF: The anatomy of a chemical insertion reaction R. L. Jaffe NASA Ames Research Center, Moffett theoretical investigation of the gas phase reaction Ca + HF-CaF + H is reported. The overall study involves electronic state of the Ca-F-H system, (b) careful fitting of the computed surface to an analytical form

Zare, Richard N.

116

Electronic Structure of Hf@C28 and Its Ions. 1. SCF Calculations  

Science Journals Connector (OSTI)

Electronic Structure of Hf@C28 and Its Ions. 1. SCF Calculations ... Electronic Structures of C28H4 and Hf@C28H4 and Their Ions. ... Electronic structure calculations, including relativistic core potentials and the spin?orbit interaction, have been carried out on the C28, Pa@C28, and U@C28 species. ...

Debbie Fu-Tai Tuan; Russell M. Pitzer

1995-01-01T23:59:59.000Z

117

Upgrade of the cryogenic CERN RF test facility  

SciTech Connect

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 1990s 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.

Pirotte, O.; Benda, V.; Brunner, O.; Inglese, V.; Maesen, P.; Vullierme, B. [CERN - European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Koettig, T. [ESS - European Spallation Source, Box 176, 221 00 Lund (Sweden)

2014-01-29T23:59:59.000Z

118

Cold Test Measurements on the GTF Prototype RF Gun  

SciTech Connect

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.

Gierman, S.M.

2010-12-03T23:59:59.000Z

119

Hydrogen-filled RF Cavities for Muon Beam Cooling  

SciTech Connect

Ionization cooling requires low-Z energy absorbers immersed in a strong magnetic field and high-gradient, large-aperture RF cavities to be able to cool a muon beam as quickly as the short muon lifetime requires. RF cavities that operate in vacuum are vulnerable to dark-current- generated breakdown, which is exacerbated by strong magnetic fields, and they require extra safety windows that degrade cooling, to separate RF regions from hydrogen energy absorbers. RF cavities pressurized with dense hydrogen gas will be developed that use the same gas volume to provide the energy absorber and the RF acceleration needed for ionization cooling. The breakdown suppression by the dense gas will allow the cavities to operate in strong magnetic fields. Measurements of the operation of such a cavity will be made as functions of external magnetic field and charged particle beam intensity and compared with models to understand the characteristics of this technology and to develop mitigating strategies if necessary.

CHARLES, Ankenbrandt

2009-04-17T23:59:59.000Z

120

Ge interactions on HfO{sub 2} surfaces and kinetically driven patterning of Ge nanocrystals on HfO{sub 2}  

SciTech Connect

Germanium interactions are studied on HfO{sub 2} surfaces, which are prepared through physical vapor deposition (PVD) and by atomic layer deposition. X-ray photoelectron spectroscopy and temperature-programed desorption are used to follow the reactions of germanium on HfO{sub 2}. Germanium chemical vapor deposition at 870 K on HfO{sub 2} produces a GeO{sub x} adhesion layer, followed by growth of semiconducting Ge{sup 0}. PVD of 0.7 ML Ge (accomplished by thermally cracking GeH{sub 4} over a hot filament) also produces an initial GeO{sub x} layer, which is stable up to 800 K. PVD above 2.0 ML deposits semiconducting Ge{sup 0}. Temperature programed desorption experiments of {approx}1.0 ML Ge from HfO{sub 2} at 400-1100 K show GeH{sub 4} desorption below 600 K and GeO desorption above 850 K. These results are compared to Ge on SiO{sub 2} where GeO desorption is seen at 550 K. Exploiting the different reactivity of Ge on HfO{sub 2} and SiO{sub 2} allows a kinetically driven patterning scheme for high-density Ge nanoparticle growth on HfO{sub 2} surfaces that is demonstrated.

Stanley, Scott K.; Joshi, Sachin V.; Banerjee, Sanjay K.; Ekerdt, John G. [Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712-0231 (United States); Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, Texas 78712-0240 (United States); Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712-0231 (United States)

2006-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Transition strengths in 86Nb and 86Zr  

Science Journals Connector (OSTI)

Mean lifetimes of states in 86Nb and 86Zr produced by the 58Ni(32S,3pn)86Nb and 58Ni(32S,4p)86Zr reactions at 130 MeV have been measured using the recoil-distance method. The B(E2) strength of 11(2) W.u. for the 8+?6+ transition in 86Nb implies weak collectivity at low excitation energies for the ?=+yrast band. The weak dipole transition strength of the 8+?7 decay suggests that the configuration for the 7? state is different from that of the other yrast states. In general, the B(E2) rates obtained for transitions in 86Zr agree with those previously published, thus supporting the suggestion of a weakly collective structure based on shell-model excitations at low energies. Hartree-Fock-Bogolyubov cranking calculations indicate a spherical shape for low-spin vacuum configuration states in 86Zr.

R. A. Kaye, J. B. Adams, A. Hale, C. Smith, G. Z. Solomon, S. L. Tabor, G. Garca-Bermdez, M. A. Cardona, A. Filevich, and L. Szybisz

1998-05-01T23:59:59.000Z

122

Zr3Al creeps in a petty pace  

Science Journals Connector (OSTI)

... striking experiment is to be fully described in a conference report to be published by ASTM. Zr3Al is ordered (Cu3Au type, L12) up to its peritectoid transformation at 1 ...

Robert W. Cahn

1978-09-21T23:59:59.000Z

123

Crystal structure of Si-doped HfO{sub 2}  

SciTech Connect

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.

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)

2014-01-21T23:59:59.000Z

124

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

E-Print Network (OSTI)

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

Cohen, Robert E.

125

Wideband high efficiency CMOS envelope amplifiers for 4G LTE handset envelope tracking RF power amplifiers  

E-Print Network (OSTI)

addition, the small equivalent resistance of 8? of the RF PAor inefficient. The equivalent resistance of RF PA, R PA ,normalized equivalent load resistance (R PA ) representing

Hassan, Muhammad

2012-01-01T23:59:59.000Z

126

Local Atomic-Jump Process of Iron in ? -Zr  

Science Journals Connector (OSTI)

After recoil implantation of Coulomb-excited Fe57 into ? -Zr at 24 K, 30% of the implanted atoms end up on interstitial positions where they experience large electric field gradients. Between 40 and 100 K the quadrupole splitting shrinks by a factor of 2 accompanied by a sharp decrease of the line intensity. This effect is interpreted as a localized diffusion of the Fe atoms jumping in the octahedral cage of the hcp Zr lattice.

Y. Yoshida; M. Menningen; R. Sielemann; G. Vogl; G. Weyer; K. Schrder

1988-07-11T23:59:59.000Z

127

Large Grain Superconducting RF Cavities at DESY  

SciTech Connect

The DESY R and D program on cavities fabricated from large grain niobium explores the potential of this material for the production of approx. 1000 nine-cell cavities for the European XFEL. The program investigates basic material properties, comparing large grain material to standard sheet niobium, as well as fabrication and preparation aspects. Several single-cell cavities of TESLA shape have been fabricated from large grain niobium. A gradient up to 41 MV/m at Q0 = 1.4{center_dot}1010 (TB = 2K) was measured after electropolishing. The first three large grain nine-cell cavities worldwide have been produced under contract of DESY with ACCEL Instruments Co. The first tests have shown that all three cavities reach an accelerating gradient up to 30 MV/m after BCP (Buffered Chemical Polishing) treatment, what exceeds the XFEL requirements for RF test in the vertical cryostat.

Singer, W.; Brinkmann, A.; Ermakov, A.; Iversen, J.; Kreps, G.; Matheisen, A.; Proch, D.; Reschke, D.; Singer, X.; Spiwek, M.; Wen, H.; Brokmeier, H. G. [DESY, Notkestrasse 85, D-22607 Hamburg (Germany); GKSS, Max-Planck-Strasse, D-21502 Geesthacht (Germany)

2007-08-09T23:59:59.000Z

128

Electrical properties of MIS capacitor using low temperature electron beam gun--evaporated HfAlO dielectrics  

E-Print Network (OSTI)

Electrical properties of MIS capacitor using low temperature electron beam gun--evaporated Hf of $1.45 nm was achieved in HfAlO films deposited by an electron beam gun evap- orator on unheated p of electron beam gun (EBG) evaporation to deposit high quality HfAlO films close to room temperature

Eisenstein, Gadi

129

Growth and characterization of UHV sputtering HfO2 film by plasma oxidation and low temperature annealing  

Science Journals Connector (OSTI)

Ultra-thin (?4.0 nm) HfO2 films were fabricated by plasma oxidation of sputtered metallic Hf films with post low temperature annealing. Advantage of this fabrication process is that the pre-deposition of Hf metal...

Q. Li; S. J. Wang; W. D. Wang; D. Z. Chi; A. C. H. Huan

2006-07-01T23:59:59.000Z

130

Studies of RF Noise Induced Bunch Lengthening at the LHC  

SciTech Connect

Radio Frequency (RF) noise induced bunch lengthening can strongly affect the Large Hadron Collider (LHC) performance through luminosity reduction, particle loss, and other effects. This work presents measurements from the LHC that better quantify the relationship between the RF noise and longitudinal emittance blowup and identify the performance limiting RF components. The experiments presented in this paper confirmed the predicted effects on the LHC bunch length growth. Dedicated measurements were conducted in the LHC to gain insight in the effect of RF noise to the longitudinal beam diffusion. It was evident that the growth rate of the bunch length is strongly related to the accelerating voltage phase noise power spectral density around f{sub s} + kf{sub rev}, as predicted in [4]. The noise threshold for 2.5 ps/hr growth was estimated to -101 dBc/Hz (SSB flat noise spectral density from f{sub s} to the edge of the closed loop bandwidth). A 9 dB margin is achieved with the current RF configuration and the BPL on. With this formalism it is now possible to estimate the effect of different operational and technical RF configurations on the LHC beam diffusion. This formalism could also be useful for the design of future RF systems and the budgeting of the allowed noise.

Mastorides, T.; Rivetta, C.; Fox, J.D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /SLAC /CERN

2011-08-17T23:59:59.000Z

131

Upgrading EMMA to Use Low-frequency RF Cavities  

SciTech Connect

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.

Ohmori, C.; Berg, J.

2011-04-30T23:59:59.000Z

132

Iris tilting and RF steering in the SLAC Linac  

SciTech Connect

For some time now, the sources of RF transverse beam steering in the SLAC Linac have been a mystery. The previously known sources, coupler asymmetries and survey misalignment, have predicted deflections which are frequently much smaller than the observed deflections. A new source of RF steering has been discovered: the tilting of accelerator irises. Measurements of iris tilting in a forty foot accelerator girder are compared with measurements of RF beam deflections and are found to be strongly correlated. 4 refs., 6 figs., 3 tabs.

Seeman, J.T.

1985-05-02T23:59:59.000Z

133

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

DOE Patents (OSTI)

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.

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

2008-04-22T23:59:59.000Z

134

Role of oxygen vacancy in HfO{sub 2}/SiO{sub 2}/Si(100) interfaces  

SciTech Connect

We have investigated the interface states in HfO{sub 2}/SiO{sub 2}/Si(100) systems that were prepared by using the in situ pulsed laser deposition technique. X-ray photoelectron spectroscopy data revealed that when the HfO{sub 2} film thickness exceeds 11 A, the film composition undergoes a systematic change from Hf silicate to oxygen-deficient HfO{sub x<2}. Furthermore, we determined that the evolution of the interface states clearly depends on the oxygen condition applied during the film growth and that the oxygen vacancy is an important parameter for Hf silicate formation.

Cho, Deok-Yong; Oh, S.-J.; Chang, Y.J.; Noh, T.W.; Jung, Ranju; Lee, Jae-Cheol [CSCMR and School of Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); ReCOE and School of Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Samsung Advanced Institute of Technology, Suwon 440-900 (Korea, Republic of)

2006-05-08T23:59:59.000Z

135

Towards forming-free resistive switching in oxygen engineered HfO{sub 2?x}  

SciTech Connect

We have investigated the resistive switching behavior in stoichiometric HfO{sub 2} and oxygen-deficient HfO{sub 2?x} thin films grown on TiN electrodes using reactive molecular beam epitaxy. Oxygen defect states were controlled by the flow of oxygen radicals during thin film growth. Hard X-ray photoelectron spectroscopy confirmed the presence of sub-stoichiometric hafnium oxide and defect states near the Fermi level. The oxygen deficient HfO{sub 2?x} thin films show bipolar switching with an electroforming occurring at low voltages and low operating currents, paving the way for almost forming-free devices for low-power applications.

Sharath, S. U., E-mail: sharath@oxide.tu-darmstadt.de; Kurian, J.; Hildebrandt, E.; Alff, L. [Institute of Materials Science, Technische Universitt Darmstadt, Alarich-Weiss-Strasse 2, 64287 Darmstadt (Germany); Bertaud, T.; Walczyk, C.; Calka, P.; Zaumseil, P.; Sowinska, M.; Walczyk, D. [IHP, Im Technologiepark 25, 15236 Frankfurt Oder (Germany); Gloskovskii, A. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt Oder (Germany); Brandenburgische Technische Universitt, Konrad-Zuse-Strasse 1, 03046 Cottbus (Germany)

2014-02-10T23:59:59.000Z

136

Low energy N{sub 2} ion bombardment for removal of (HfO{sub 2}){sub x}(SiON){sub 1-x} in dilute HF  

SciTech Connect

The ion assisted wet removal of (HfO{sub 2}){sub x}(SiON){sub 1-x} high dielectric constant (k) materials and its effect on electrical properties were investigated. Crystallization temperature of (HfO{sub 2}){sub x}(SiON){sub 1-x} increased as the percentage of SiON increased. The crystallized (HfO{sub 2}){sub 0.6}(SiON){sub 0.4} was damaged and turned to an amorphous film via incorporation of N species into the film by N{sub 2} plasma treatment. In addition, the structure of (HfO{sub 2}){sub 0.6}(SiON){sub 0.4} was disintegrated into HfO{sub 2}, SiO(N), and ON after N{sub 2} plasma treatment. N{sub 2} plasmas using low bias power were applied for wet removal of high-k films and the mechanism of the ion assisted wet removal process was explored. When high bias power was applied, the surface of source and drain regions was nitrided via the reaction between N and Si substrates. Feasibility of the low bias power assisted wet removal process was demonstrated for short channel high-k metal oxide semiconductor device fabrication by the smaller shift of threshold voltage, compared to the high bias power assisted wet removal process as well as the wet-etching-only process.

Hwang, Wan Sik; Cho, Byung-Jin; Chan, Daniel S. H.; Yoo, Won Jong [Silicon Nano Device Laboratory, Department of Electrical and Computer Engineering, National University of Singapore, E4A 02-04, Engineering Drive 3, 117576 Singapore (Singapore); SKKU Advanced Institute of Nanotechnology (SAINT) and Department of Mechanical Engineering, Sungkyunkwan University 300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

2007-07-15T23:59:59.000Z

137

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

E-Print Network (OSTI)

: The electron extraction from a low-frequency (2 MHz) inductively-coupled rf-plasma cathode is characterizedA Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source and rf-plasma source, rf-power and xenon gas flow. The results demonstrate that the electron supply from

138

Mixed cation phases in sputter deposited HfO{sub 2}-TiO{sub 2} nanolaminates  

SciTech Connect

Nanolaminate HfO{sub 2}-TiO{sub 2} films are grown by reactive sputter deposition on unheated fused SiO{sub 2}, sequentially annealed at 573 to 973 K, and studied by x-ray diffraction. A nanocrystalline structure of orthorhombic (o) HfTiO{sub 4} adjacent to an interface followed by monoclinic (m) Hf{sub 1-x}Ti{sub x}O{sub 2} is identified. m-Hf{sub 1-x}Ti{sub x}O{sub 2}, a metastable phase, is isomorphous with m-HfO{sub 2} and a high pressure phase, m-HfTiO{sub 4}. A Vegard's law analysis shows that the Ti atomic fraction in m-Hf{sub 1-x}Ti{sub x}O{sub 2} is much greater than Ti equilibrium solubility in m-HfO{sub 2}. A space group-subgroup argument proposes that m-Hf{sub 1-x}Ti{sub x}O{sub 2} arises from an o/m-HfTiO{sub 4} second order phase transition to accommodate the larger Hf atom.

Cisneros-Morales, M. C.; Aita, C. R. [Advanced Coatings Experimental Laboratory, College of Engineering and Applied Science, University of Wisconsin-Milwaukee, P.O. Box 784, Milwaukee, Wisconsin 53201 (United States)

2008-07-14T23:59:59.000Z

139

RF Micro Devices Inc RFMD | Open Energy Information  

Open Energy Info (EERE)

RF Micro Devices Inc RFMD RF Micro Devices Inc RFMD Jump to: navigation, search Name RF Micro Devices, Inc. (RFMD) Place Greensboro, North Carolina Zip 27409-9421 Product RF Micro Devices, Inc. is a global leader in the design and manufacture of high-performance semiconductor components. Coordinates 44.576059°, -72.294016° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.576059,"lon":-72.294016,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

140

Development of the RF plasma source at atmospheric pressure  

Science Journals Connector (OSTI)

A radio frequency (RF) plasma source operates by feeding helium or argon gas through two coaxial electrodes driven by a 13.56 \\{MHz\\} RF source. In order to prevent an arc discharge, a dielectric material is loaded outside the center electrode. A stable, arc-free discharge is produced at a flow rate of 1.5 l/min of helium gas. The temperature of the gas flame varies from 100 to 150 C depending on the RF power. The breakdown voltage also changes when the flow rate varies. The plasma generation in a hot chamber is much more efficient than that in a cold chamber. The plasma characteristics are diagnosed by using optical emission spectroscopy. One of the applications of the RF plasma source is the printed circuit board (PCB) cleaning process, needed for environmental protection. The PCB cleaning device forms an asymmetric biaxial reactor.

Jung G. Kang; Hyoung S. Kim; Sung W. Ahn; Han S. Uhm

2003-01-01T23:59:59.000Z

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141

BN/Graphene/BN Transistors for RF Applications  

E-Print Network (OSTI)

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 ...

Taychatanapat, Thiti

142

RF Sputtering for preparing substantially pure amorphous silicon monohydride  

DOE Patents (OSTI)

A process for controlling the dihydride and monohydride bond densities in hydrogenated amorphous silicon 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 silicon hydride onto the substrate, the dihydride bond density decreasing with an increase in the rf power density. Substantially pure monohydride films may be produced.

Jeffrey, Frank R. (Ames, IA); Shanks, Howard R. (Ames, IA)

1982-10-12T23:59:59.000Z

143

Supply Chain Planning Analyst 4 Optical Components /RF Products  

E-Print Network (OSTI)

Components/RF Products Technology Domain Teams. The SCPA will have responsibility for managing management, subcontract administration, procurement, mission assurance, engineering, and manufacturing Qualifications: The selected analysts must have the demonstrated ability to thrive in a dynamic environment

Heller, Barbara

144

RF power amplifier linearity compensation for MRI systems  

E-Print Network (OSTI)

In this thesis, a polar-feedback linearization system for use with MRI RF power amplifiers was designed and simulated. The design here presented is intended to replace Analogic's (located in Peabody, Massachusetts) ...

Torres Chico, Gabriel

2010-01-01T23:59:59.000Z

145

Suppression of interfacial reaction for HfO{sub 2} on silicon by pre-CF{sub 4} plasma treatment  

SciTech Connect

In this letter, the effects of pre-CF{sub 4} plasma treatment on Si for sputtered HfO{sub 2} gate dielectrics are investigated. The significant fluorine was incorporated at the HfO{sub 2}/Si substrate interface for a sample with the CF{sub 4} plasma pretreatment. The Hf silicide was suppressed and Hf-F bonding was observed for the CF{sub 4} plasma pretreated sample. Compared with the as-deposited sample, the effective oxide thickness was much reduced for the pre-CF{sub 4} plasma treated sample due to the elimination of the interfacial layer between HfO{sub 2} and Si substrate. These improved characteristics of the HfO{sub 2} gate dielectrics can be explained in terms of the fluorine atoms blocking oxygen diffusion through the HfO{sub 2} film into the Si substrate.

Lai, C.S.; Wu, W.C.; Chao, T.S.; Chen, J.H.; Wang, J.C.; Tay, L.-L.; Rowell, Nelson [Department of Electronic Engineering, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Department of Electronic Physics, National Chiao Tung University, 1001 Ta Hsueh Rd., Hsinchu 300, Taiwan (China); Department of Electronics Engineering, National Chiao Tung University, 1001 Ta Hsueh Rd., Hsinchu 300, Taiwan (China); Nanya Technology Corporation, Hwa-Ya Technology Park, 669 Fu-Hsing 3rd Rd., Kueishan, Taoyuan 338, Taiwan (China); Institute for Microstructural Sciences, National Research Council of Canada, 1200 Montreal Road, Ottawa, Ontario K1A 0R6 (Canada)

2006-08-14T23:59:59.000Z

146

Handbook for Gas Filled RF Cavity Aficionados'  

SciTech Connect

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.

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

2009-05-01T23:59:59.000Z

147

RF heating needs and plans for ITER  

SciTech Connect

RF heating systems are required to deliver more than half of the total auxiliary power to operate ITER successfully through the different levels. To achieve this goal, systems in the range of ICRF, LHF and ECRF will be implemented for different tasks in different phases of operation. Power levels proposed to be used in different ranges will vary depending on the needs. Different mixes of power will depend on the physics needs of the experimental programmes. Lower Hybrid power of 20 MW at 5.0 GHz is not planned for the startup phase and therefore no procurement scheme exists at the present time. 20 MW will be delivered into the plasma at 40 to 55 MHz as well as at 170 GHz with the help of Ion Cyclotron Heating (ICH) and Electron Cyclotron Heating (ECH) systems respectively. All the heating systems will have the capability to operate in continuous mode. A dedicated ECH 3.0 MW system at 127.6 GHz will be used for plasma breakdown and start up.

Bora, Dhiraj; Beaumont, B.; Kobayashi, N.; Tanga, A. [ITER Organization, Joint Work Site, Cadarache (France); Goulding, R.; Swain, D. [Oak Ridge National Laboratory (United States); Jacquinot, J. [Cabinet of High Commissioner for Atomic Energy, CEA Gif-sur-Yvette (France)

2007-09-28T23:59:59.000Z

148

Pulses inside the pulse mode of operation at RF Gun  

E-Print Network (OSTI)

Pulses inside the pulse mode of operation at RF Gun V. Vogel, V. Ayvazyan, K. Floettmann, D. Lipka a PiP mode of operation at RF Gun · What we need, to operate FLASH in the PiP mode · PiP study-Universitaet Bochum) Alternative: SC GUN DC GUN Cold GUN in PiP mode Cold Traveling wave GUN Why we need a PiP mode

149

Intrinsic Kinetics of Ethanol Dehydration Over Lewis Acidic Ordered Mesoporous Silicate, Zr-KIT-6  

Science Journals Connector (OSTI)

Lewis acidic Zr-KIT-6 catalyst was tested for ethanol dehydration. Under the reaction conditions studied (...P ethanol=5% in N2...), Zr-KIT-6 materials showed high ethylene selectivity (~80%) ...

Qing Pan; Anand Ramanathan; W. Kirk Snavely; Raghunath V. Chaudhari

2014-11-01T23:59:59.000Z

150

Determination of Boron in Silicate Samples by Direct Aspiration of Sample HF Solutions into ICPMS  

Science Journals Connector (OSTI)

A rapid and precise technique for the determination of boron content in silicate rocks was developed by employing isotope dilution inductively coupled plasma mass spectrometry with a flow injection system (FI-ID-ICPMS). The sample was decomposed with HF ...

Akio Makishima; Eizo Nakamura; Toshio Nakano

1997-09-15T23:59:59.000Z

151

Magnetospheric wave injection by modulated HF heating of the auroral electrojet.  

E-Print Network (OSTI)

?? Modulated High Frequency (HF, 3-30 MHz) heating of the auroral electrojet to generate electromagnetic waves in the Extremely Low Frequency (ELF, 3-3000 Hz) and (more)

Golkowski, Mark

2009-01-01T23:59:59.000Z

152

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

E-Print Network (OSTI)

) 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

Schöne, Bernd R.

153

Observations of small-scale plasma density depletions in arecibo HF heating experiments  

SciTech Connect

Observations of incoherent scattering of electromagnetic waves at UHF from Langmuir waves by a new scheme involving linear frequency modulation (chirping) of a UHF transmitter and the demodulation (dechirping) of the received signals have been applied during HF heating experiments. These observations show that the high power HF wave used for ionospheric modification creates small-scale plasma depletions instantly on a time scale of 5 ms. For a plasma frequency of 5.1 MHz, plasma frequency gradient of the order of 50 kHz/km, and power density input of the HF heater wave of 8.0 x 10/sup -5/ W/m/sup 2/ the depletion ranged from 3 to 5%. This appears to provide direct evidence that the HF-induced modifications involve Langmuir waves trapped in density cavities. copyrightAmerican Geophysical Union 1987

Isham, B.; Birkmayer, W.; Hagfors, T.; Kofman, W.

1987-05-01T23:59:59.000Z

154

Simulation and detection of tsunami signatures in ocean surface currents measured by HF radar  

Science Journals Connector (OSTI)

High-frequency (HF) surface wave radars provide the unique capability to continuously monitor the coastal environment far beyond the range of conventional microwave radars. Bragg-resonant backscattering by ocean ...

Klaus-Werner Gurgel; Anna Dzvonkovskaya; Thomas Pohlmann; Thomas Schlick

2011-10-01T23:59:59.000Z

155

In situ characterization of initial growth of HfO{sub 2}  

SciTech Connect

The initial growth of HfO{sub 2} on Si (111) is monitored in situ by ultrahigh vacuum (UHV) scanning probe microscopy. UHV scanning tunneling microscopy and UHV atomic force microscopy reveal the topography of HfO{sub 2} films in the initial stage. The chemical composition is further confirmed by x-ray photoelectron spectroscopy. Scanning tunneling spectroscopy is utilized to inspect the evolution of the bandgap. When the film thickness is less than 0.6 nm, the bandgap of HfO{sub 2} is not completely formed. A continuous usable HfO{sub 2} film with thickness of about 1.2 nm is presented in this work.

Wang, L.; Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Xue, K.; Xu, J. B. [Department of Electronic Engineering, Chinese University of Hong Kong, Shatin, New Territories (Hong Kong)

2009-01-19T23:59:59.000Z

156

Germanium diffusion during HfO{sub 2} growth on Ge by molecular beam epitaxy  

SciTech Connect

The authors study the Ge diffusion during HfO{sub 2} growth by molecular beam epitaxy on differently in situ prepared germanium substrates and at different growth temperatures. While HfO{sub 2} layers grown directly on Ge do not show any germanium contamination, oxygen rich interfacial layers such as GeO{sub x} or GeO{sub x}N{sub y} partly dissolve into the HfO{sub 2} layer, giving rise to high Ge contamination (from 1% to 10%). The use of nitridated interfacial layers does not prevent Ge diffusion into the HfO{sub 2} during the growth process because of the high oxygen content present in the nitridated germanium layer.

Ferrari, S.; Spiga, S.; Wiemer, C.; Fanciulli, M.; Dimoulas, A. [Laboratorio MDM-INFM-CNR, Via Olivetti, 2 Agrate Brianza, Milano 20041 (Italy); MBE Laboratory, Institute of Materials Science, DEMOKRITOS National Center for Scientific Research, 153 10 Athens (Greece)

2006-09-18T23:59:59.000Z

157

Wind-speed inversion from HF radar first-order backscatter signal  

Science Journals Connector (OSTI)

Land-based high-frequency (HF) radars have the unique capability of continuously monitoring ocean surface environments at ranges up to 200km off the coast. They provide reliable data on ocean surface currents an...

Wei Shen; Klaus-Werner Gurgel; George Voulgaris; Thomas Schlick

2012-01-01T23:59:59.000Z

158

Plasma etching of HfO{sub 2} at elevated temperatures in chlorine-based chemistry  

SciTech Connect

Plasma etching of HfO{sub 2} at an elevated temperature is investigated in chlorine-based plasmas. Thermodynamic studies are performed in order to determine the most appropriate plasma chemistry. The theoretical calculations show that chlorocarbon gas chemistries (such as CCl{sub 4} or Cl{sub 2}-CO) can result in the chemical etching of HfO{sub 2} in the 425-625 K temperature range by forming volatile effluents such as HfCl{sub 4} and CO{sub 2}. The etching of HfO{sub 2} is first studied on blanket wafers in a high density Cl{sub 2}-CO plasma under low ion energy bombardment conditions (no bias power). Etch rates are presented and discussed with respect to the plasma parameters. The evolution of the etch rate as function of temperature follows an Arrhenius law indicating that the etching comes from chemical reactions. The etch rate of HfO{sub 2} is about 110 A /min at a temperature of 525 K with a selectivity towards SiO{sub 2} of 15. x-ray photoelectron spectroscopy analyses (XPS) reveal that neither carbon nor chlorine is detected on the HfO{sub 2} surface, whereas a chlorine-rich carbon layer is formed on top of the SiO{sub 2} surface leading to the selectivity between HfO{sub 2} and SiO{sub 2}. A drift of the HfO{sub 2} etch process is observed according to the chamber walls conditioning due to chlorine-rich carbon coatings formed on the chamber walls in a Cl{sub 2}-CO plasma. To get a very reproducible HfO{sub 2} etch process, the best conditioning strategy consists in cleaning the chamber walls with an O{sub 2} plasma between each wafer. The etching of HfO{sub 2} is also performed on patterned wafers using a conventional polysilicon gate. The first result show a slight HfO{sub 2} foot at the bottom of the gate and the presence of hafnium oxide-based residues in the active areas.

Helot, M.; Chevolleau, T.; Vallier, L.; Joubert, O.; Blanquet, E.; Pisch, A.; Mangiagalli, P.; Lill, T. [STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France); Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des martyrs (CEA-LETI), 38054 Grenoble Cedex 09 (France); LTPCM/INPG-CNRS-UJF, 1130 rue de la piscine, 38402 Saint-Martin-d'Heres (France); Applied Materials, 974 E. Arques Ave. M/S 81334, Sunnyvale, California 94086 (United States)

2006-01-15T23:59:59.000Z

159

Optical Properties of ZrO2Containing Anodic Coatings on Aluminum  

Science Journals Connector (OSTI)

Anodic oxide coatings (AOC) formed at the potentials of spark breakdowns...2ZrF6) contain up to 36 wt.% of Zr. The modification of ZrO2 in AOC is tetragonal. The reflection coefficients of AOC have been measured ...

P. M. Nedozorov; K. N. Kilin; T. P. Yarovaya

2001-07-01T23:59:59.000Z

160

ccsd00001116 Nucleation of Al 3 Zr and Al 3 Sc in aluminum alloys  

E-Print Network (OSTI)

ccsd­00001116 (version 1) : 4 Feb 2004 Nucleation of Al 3 Zr and Al 3 Sc in aluminum alloys: from 4, 2004) Zr and Sc precipitate in aluminum alloys to form the compounds Al3Zr and Al3Sc which

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Chemical states and electronic structure of a HfO(-2) / Ge(001) interface  

SciTech Connect

We report the chemical bonding structure and valence band alignment at the HfO{sub 2}/Ge (001) interface by systematically probing various core level spectra as well as valence band spectra using soft x-rays at the Stanford Synchrotron Radiation Laboratory. We investigated the chemical bonding changes as a function of depth through the dielectric stack by taking a series of synchrotron photoemission spectra as we etched through the HfO{sub 2} film using a dilute HF-solution. We found that a very non-stoichiometric GeO{sub x} layer exists at the HfO{sub 2}/Ge interface. The valence band spectra near the Fermi level in each different film structure were carefully analyzed, and as a result, the valence band offset between Ge and GeO{sub x} was determined to be {Delta}E{sub v} (Ge-GeO{sub x}) = 2.2 {+-} 0.15 eV, and that between Ge and HfO{sub 2}, {Delta}E{sub v} (Ge-HfO{sub 2}) = 2.7 {+-} 0.15 eV.

Seo, Kang-ill; McIntyre, Paul C.; /Stanford U., Materials Sci. Dept.; Sun, Shiyu; Lee, Dong-Ick; Pianetta, Piero; /SLAC, SSRL; Saraswat, Krishna C.; /Stanford U., Elect.

2005-05-04T23:59:59.000Z

162

HfO{sub x}N{sub y} gate dielectric on p-GaAs  

SciTech Connect

Plasma nitridation method is used for nitrogen incorporation in HfO{sub 2} based gate dielectrics for future GaAs-based devices. The nitrided HfO{sub 2} (HfO{sub x}N{sub y}) films on p-GaAs improve metal-oxide-semiconductor device characteristics such as interface state density, accumulation capacitance, hysteresis, and leakage current. An equivalent oxide thickness of 3.6 nm and a leakage current density of 10{sup -6} A cm{sup -2} have been achieved at V{sub FB}-1 V for nitrided HfO{sub 2} films. A nitride interfacial layer (GaAsO:N) was observed at HfO{sub 2}-GaAs interface, which can reduce the outdiffusion of elemental Ga and As during post-thermal annealing process. Such suppression of outdiffusion led to a substantial enhancement in the overall dielectric properties of the HfO{sub 2} film.

Dalapati, G. K.; Sridhara, A.; Wong, A. S. W.; Chia, C. K.; Chi, D. Z. [Institute of Materials Research and Engineering, A-STAR - Agency for Science, Technology and Research, 3 Research Link, Singapore 117602 (Singapore)

2009-02-16T23:59:59.000Z

163

Heavy Quasiparticles in the Ferromagnetic Superconductor ZrZn2  

Science Journals Connector (OSTI)

We report a study of the de Haasvan Alphen effect in the normal state of the ferromagnetic superconductor ZrZn2. Our results are generally consistent with a linear muffin-tin orbital band structure which predicts four exchange-split Fermi surface sheets. Quasiparticle effective masses are enhanced by a factor of 4.9 implying a strong coupling to magnetic excitations or phonons. ZrZn2 is unique among metallic ferromagnets in that it has a very large density of states in the ferromagnetic phase.

S. J. C. Yates; G. Santi; S. M. Hayden; P. J. Meeson; S. B. Dugdale

2003-02-06T23:59:59.000Z

164

Microsoft PowerPoint - rf_5year_review  

NLE Websites -- All DOE Office Websites (Extended Search)

RF Research Program RF Research Program DOE Review of C-Mod Five-Year Proposal May 13-14, 2003 MIT PSFC Presented by Steve J.Wukitch Outline: 1. Overview of the RF Program 2. Five-year plan Overview of the RF Program AT: validate steady state operation with target parameters β N = 3, I non = 100%, I BS ~ 70%, H 89 ~ 2.5, for t pulse > t L/R . BPX: demonstrate the viability of high performance plasmas, B T = 8T, I p = 2 MA, P = 6 MW, H 89 ≥ 2, Z eff < 1.5. B T = 5.4T, I p = 1.4 MA, P = 6 MW, H 89 = 2 (ITER demo) Exclusively use RF power for auxiliary heating and current drive. variable variable fixed Phase 2 x 4 Strap 4 Strap 2 x 2 Strap Antenna 4 MW 40-80 MHz J-port 2 x 4 MW 2 x 2 MW Power 40-80 MHz ~ 80 MHz Frequency E & J-port D & E-port 2005-2008 2002-2005 4.6 GHz 4.6 GHz Frequency 16 x 250 kW

165

RF Power Upgrade for CEBAF at Jefferson Laboratory  

SciTech Connect

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.

Andrew Kimber,Richard Nelson

2011-03-01T23:59:59.000Z

166

Phase Stable RF-over-fiber Transmission using Heterodyne Interferometry  

SciTech Connect

New scientific applications require phase-stabilized RF distribution to multiple remote locations. These include phased-array radio telescopes and short pulse free electron lasers. RF modulated onto a CW optical carrier and transmitted via fiber is capable of low noise, but commercially available systems aren't long term stable enough for these applications. Typical requirements are for less than 50fs long term temporal stability between receivers, which is 0.05 degrees at 3GHz. Good results have been demonstrated for RF distribution schemes based on transmission of short pulses, but these require specialized free-space optics and high stability mechanical infrastructure. We report a method which uses only standard telecom optical and RF components, and achieves less than 20fs RMS error over 300m of standard single-mode fiber. We demonstrate stable transmission of 3GHz over 300m of fiber with less than 0.017 degree (17fs) RMS phase error. An interferometer measures optical phase delay, providing information to a feed-forward correction of RF phase.

Wilcox, R.; Byrd, J. M.; Doolittle, L.; Huang, G.; Staples, J. W.

2010-01-02T23:59:59.000Z

167

Structural Characterization and Catalytic Activity of Nanosized CexM1-xO2 (M = Zr and Hf) Mixed Oxides  

Science Journals Connector (OSTI)

RS measurements suggest a defective structure of the mixed oxides resulting in the formation of oxygen vacancies. ... Improvements in such features are currently in demand for designing better catalytic cartridges for new-generation cleaner cars. ...

Benjaram M. Reddy; Pankaj Bharali; Pranjal Saikia; Sang-Eon Park; Maurits W. E. van den Berg; Martin Muhler; Wolfgang Grnert

2008-07-16T23:59:59.000Z

168

Correlation between corrosion performance and surface wettability in ZrTiCuNiBe bulk metallic glasses  

E-Print Network (OSTI)

Correlation between corrosion performance and surface wettability in ZrTiCuNiBe bulk metallic June 2010 The corrosion properties of two Zr-based bulk metallic glass, Zr41Ti14Cu12Ni10Be23 LM1 and Zr potential, LM1b showed superior corrosion resistance to LM1. Under identical sample preparation and testing

Zheng, Yufeng

169

InGaZnO thin film transistor with HfO{sub 2} gate insulator prepared using various O{sub 2}/(Ar + O{sub 2}) gas ratios  

SciTech Connect

We have investigated the effect of the deposition of an HfO{sub 2} thin film as a gate insulator with different O{sub 2}/(Ar + O{sub 2}) gas ratios using RF magnetron sputtering. The HfO{sub 2} thin film affected the device performance of amorphous indiumgalliumzinc oxide transistors. The performance of the fabricated transistors improved monotonously with increasing O{sub 2}/(Ar + O{sub 2}) gas ratio: at a ratio of 0.35, the field effect mobility of the amorphous InGaZnO thin film transistors was improved to 7.54 cm{sup 2}/(V s). Compared to those prepared with an O{sub 2}/(Ar + O{sub 2}) gas ratio of 0.05, the field effect mobility of the amorphous InGaZnO thin film transistors was increased to 1.64 cm{sup 2}/(V s) at a ratio of 0.35. This enhancement in the field effect mobility was attributed to the reduction of the root mean square roughness of the gate insulator layer, which might result from the trap states and surface scattering of the gate insulator layer at the lower O{sub 2}/(Ar + O{sub 2}) gas ratio.

Jo, Young Je [WCU Department of Printed Electronics, Sunchon National University, Chonnam 540-742 (Korea, Republic of)] [WCU Department of Printed Electronics, Sunchon National University, Chonnam 540-742 (Korea, Republic of); Lee, In-Hwan [School of Advanced Materials Engineering, Chonbuk National University, Chonju 561-756 (Korea, Republic of)] [School of Advanced Materials Engineering, Chonbuk National University, Chonju 561-756 (Korea, Republic of); Kwak, Joon Seop, E-mail: jskwak@sunchon.ac.kr [WCU Department of Printed Electronics, Sunchon National University, Chonnam 540-742 (Korea, Republic of)

2012-10-15T23:59:59.000Z

170

HOM Coupler Optimisation for the Superconducting RF Cavities in ESS  

E-Print Network (OSTI)

The European Spallation Source (ESS) will be the worlds most powerful next generation neutron source. It consists of a linear accelerator, target, and instruments for neutron experiments. The linac is designed to accelerate protons to a ?nal energy of 2.5 GeV, with an average design beam power of 5 MW, for collision with a target used to produce a high neutron ?ux. A section of the linac will contain Superconducting RF (SCRF) cavities designed at 704 MHz. Beam induced HOMs in these cavities may drive the beam unstable and increase the cryogenic load, therefore HOM couplers are installed to provide suf?cient damping. Previous studies have shown that these couplers are susceptible to multipacting, a resonant process which can absorb RF power and lead to heating effects. This paper will show how a coupler suffering from multipacting has been redesigned to limit this effect. Optimisation of the RF damping is also discussed.

Ainsworth, R; Calaga, R

2012-01-01T23:59:59.000Z

171

In situ RF/microwave remediation of soil experiment overview  

SciTech Connect

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.

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)

1995-09-01T23:59:59.000Z

172

A computer program for HVDC converter station RF noise calculations  

SciTech Connect

HVDC converter station operations generate radio frequency (RF) electromagnetic (EM) noise which could interfere with adjacent communication and computer equipment, and carrier system operations. A generic Radio Frequency Computer Analysis Program (RAFCAP) for calculating the EM noise generated by valve ignition of a converter station has been developed as part of a larger project. The program calculates RF voltages, currents, complex power, ground level electric field strength and magnetic flux density in and around an HVDC converter station. The program requires the converter station network to be represented by frequency dependent impedance functions. Comparisons of calculated and measured values are given for an actual HVDC station to illustrate the validity of the program. RAFCAP is designed to be used by engineers for the purpose of calculating the RF noise produced by the igniting of HVDC converter valves.

Kasten, D.G.; Caldecott, R.; Sebo, S.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering); Liu, Y. (Virginia Polytechnic Inst. State Univ., Blacksburg, VA (United States). Bradley Dept. of Electrical Engineering)

1994-04-01T23:59:59.000Z

173

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

SciTech Connect

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 (400600?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.

Soares, G. V., E-mail: gabriel.soares@ufrgs.br; Feij, T. O. [Instituto de Fsica, UFRGS, Porto Alegre 91509-900 (Brazil); Baumvol, I. J. R. [Instituto de Fsica, UFRGS, Porto Alegre 91509-900 (Brazil); Universidade de Caxias do Sul, Caxias do Sul 95070-560 (Brazil); Aguzzoli, C. [Universidade de Caxias do Sul, Caxias do Sul 95070-560 (Brazil); Krug, C. [Instituto de Fsica, UFRGS, Porto Alegre 91509-900 (Brazil); CEITEC S.A., Porto Alegre 91550-000 (Brazil); Radtke, C. [Instituto de Qumica, UFRGS, Porto Alegre 91509-900 (Brazil)

2014-01-27T23:59:59.000Z

174

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

SciTech Connect

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 (1x)} 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.

Min Xu

2008-08-18T23:59:59.000Z

175

The Los Alamos VXI-based modular RF control system  

SciTech Connect

This paper describes the design and implementation of the Los Alamos modular RF control system, which provides high-performance feedback and/or feedforward control of RF accelerator cavities. This is a flexible, modular control system which has been realized in the industry-standard VXI cardmodular format. A wide spectrum of system functionality can be accommodated simply by incorporating only those modules and features required for a particular application. The fundamental principles of the design approach are discussed. Details of the VXI implementation are given, including the system architecture and interfaces, performance capabilities, and available features.

Jachim, S.P.; Ziomek, C.; Natter, E.F.; Regan, A.H.; Hill, J.; Eaton, L.; Gutscher, W.D.; Curtin, M.; Denney, P.; Hansberry, E.; Brooks, T.

1993-01-01T23:59:59.000Z

176

The Los Alamos VXI-based modular RF control system  

SciTech Connect

This paper describes the design and implementation of the Los Alamos modular RF control system, which provides high-performance feedback and/or feedforward control of RF accelerator cavities. This is a flexible, modular control system which has been realized in the industry-standard VXI cardmodular format. A wide spectrum of system functionality can be accommodated simply by incorporating only those modules and features required for a particular application. The fundamental principles of the design approach are discussed. Details of the VXI implementation are given, including the system architecture and interfaces, performance capabilities, and available features.

Jachim, S.P.; Ziomek, C.; Natter, E.F.; Regan, A.H.; Hill, J.; Eaton, L.; Gutscher, W.D.; Curtin, M.; Denney, P.; Hansberry, E.; Brooks, T.

1993-06-01T23:59:59.000Z

177

The MuCool Test Area and RF Program  

SciTech Connect

The MuCool RF Program focuses on the study of normal conducting RF structures operating in high magnetic field for applications in muon ionization cooling for Neutrino Factories and Muon Colliders. This paper will give an overview of the program, which will include a description of the test facility and its capabilities, the current test program, and the status of a cavity that can be rotated in the magnetic field which allows for a more detailed study of the maximum stable operating gradient vs. magnetic field strength and angle.

Bross, A D; Jansson, A; Moretti, A; Yonehara, K; Huang, D; Torun, Y; Li, D; Norem, J; Palmer, R B; Stratakis, D

2010-05-01T23:59:59.000Z

178

Spectroscopic analysis of Al and N diffusion in HfO{sub 2}  

SciTech Connect

X-ray photoelectron core level spectroscopy, secondary ion mass spectroscopy, spectroscopic ellipsometry, and extended x-ray absorption fine structure measurements have been employed to distinguish the effects of Al and N diffusion on the local bonding and microstructure of HfO{sub 2} and its interface with the Si substrate in (001)Si/SiO{sub x}/2 nm HfO{sub 2}/1 nm AlO{sub x} film structures. The diffusion of Al from the thin AlO{sub x} cap layer deposited on both annealed and unannealed HfO{sub 2} has been observed following anneal in N{sub 2} and NH{sub 3} ambient. Both N{sub 2} and NH{sub 3} subsequent anneals were performed to decouple incorporated nitrogen from thermal reactions alone. Causal variations in the HfO{sub 2} microstructure combined with the dependence of Al and N diffusion on initial HfO{sub 2} conditions are presented with respect to anneal temperature and ambient.

Lysaght, P. S.; Price, J.; Kirsch, P. D. [SEMATECH, 257 Fuller Rd, Albany, New York 12203 (United States); Woicik, J. C.; Weiland, C. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Sahiner, M. A. [Seton Hall University, 400 South Orange Ave, South Orange, New Jersey 07079 (United States)

2012-09-15T23:59:59.000Z

179

HF treatment effect for carbon deposition on silicon (111) by DC sputtering technique  

SciTech Connect

Surface modifications of Si (111) substrate by HF solution for thin film carbon deposition have been systematically studied. Thin film carbon on Si (111) has been deposited using DC Unbalanced Magnetron Sputtering with carbon pellet doped by 5% Fe as the target. EDAX characterization confirmed that the carbon fraction on Si substrate much higher by dipping a clean Si substrate by HF solution before sputtering process in comparison with carbon fraction on Si substrate just after conventional RCA. Moreover, SEM and AFM images show the uniform thin film carbon on Si with HF treatment, in contrast to the Si without HF solution treatment. These experimental results suggest that HF treatment of Si surface provide Si-H bonds on top Si surface that useful to enhance the carbon deposition during sputtering process. Furthermore, we investigate the thermal stability of thin film carbon on Si by thermal annealing process up to 900 C. Atomic arrangements during annealing process were characterized by Raman spectroscopy. Raman spectra indicate that thin film carbon on Si is remaining unchanged until 600 C and carbon atoms start to diffuse toward Si substrate after annealing at 900 C.

Aji, A. S., E-mail: aji.ravazes70@gmail.com; Darma, Y., E-mail: aji.ravazes70@gmail.com [Quantum Semiconductor and Devices Lab., Physics of Material Electronics Research Division, Department of Physics, Institut Teknologi Bandung (Indonesia)

2014-03-24T23:59:59.000Z

180

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

E-Print Network (OSTI)

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.

Chattopadhyay, S.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Influence of the Radio-Frequency source properties on RF-based atom traps  

Science Journals Connector (OSTI)

We discuss the quality required for the RF source used to trap neutral atoms in RF-dressed potentials. We illustrate this discussion with experimental results obtained on a Bose-Einstein condensation experimen...

O. Morizot; L. Longchambon; R. Kollengode Easwaran

2008-04-01T23:59:59.000Z

182

Advances in Broadband RF Sensing for Real-time Control of Plasma-Based Semiconductor Processing  

E-Print Network (OSTI)

to standard RF metrology. The system uses an antenna in the glow discharge to excite the bulk plasma identification of process conditions for standard RF sensing, and 99:5 correct identification of process

Grizzle, Jessy W.

183

E-Print Network 3.0 - accelerating rf station Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

by a 1.25-T -decay channel with phase-rotation via rf (to compress... to beam tests; Test 70-MHz rf cavity (+ 1.25-T magnet) 3 m from target; Characterize ... Source:...

184

Electronic structure of HfN0.93(100) studied by angle-resolved photoemission  

Science Journals Connector (OSTI)

An experimental and theoretical study of the electronic structure of HfN is reported. Results from angle-resolved photoemission experiments on HfN0.93(100) are presented and interpreted with use of calculated results. The bulk-band structure of stoichiometric HfN was calculated relativistically and nonrelativistically using the linear augmented-plane-wave method. Predicted band locations and dispersions along the ?X direction are compared with experimental results. In general the experiment indicates smaller bandwidths and locates the bands deeper below the Fermi level than the calculated values. Calculations of photoemission spectra, made nonrelativistically, are also reported and these spectra are found to reflect the recorded spectra fairly well.

J. Lindstrm; L. I. Johansson; P. E. S. Persson; A. Callens; D. S. L. Law; A. N. Christensen

1989-02-15T23:59:59.000Z

185

On the K{sup {pi}} = 0{sup +} rotational bands in the {sup 178}Hf nucleus  

SciTech Connect

The results obtained by studying the angular distributions of gamma rays with respect to the neutron-beam axis in the reaction {sup 178}Hf(n, n'{gamma}) involving the deexcitation of the K{sup {pi}} = 0{sup +} rotational bands of {sup 178}Hf are presented.New information about themultipole-mixing parameter {delta} in gamma transitions from the levels of these bands is obtained. The K{sup {pi}} = 0{sub 4}{sup +} band is constructed anew. The relationship between the parameter {delta} for the (2{sup +}0{sub n}-2{sup +}0{sub 1}) gamma transition and the energy gap {Delta}{sub n} = E{sub lev}(2{sup +}0{sub n}) - E{sub lev}(0{sup +}0{sub n}), on one hand, and the quasiparticle structure of the rotational band, on the other hand, is discussed for {sup 178}Hf on the basis of the quasiparticle-phonon model.

Govor, L. I.; Demidov, A. M.; Kurkin, V. A., E-mail: kurkin@polyn.kiae.su; Mikhailov, I. V. [Russian Research Centre Kurchatov Institute (Russian Federation)

2010-07-15T23:59:59.000Z

186

Band offsets in HfO{sub 2}/InGaZnO{sub 4} heterojunctions  

SciTech Connect

The valence band discontinuity ({Delta}E{sub V}) of sputter deposited HfO{sub 2}/InZnGaO{sub 4} (IGZO) heterostructures was obtained from x-ray photoelectron spectroscopy measurements. The HfO{sub 2} exhibited a bandgap of 6.07 eV from absorption measurements. A value of {Delta}E{sub V} = 0.48 {+-} 0.025 eV was obtained by using the Ga 2p{sub 3/2}, Zn 2p{sub 3/2}, and In 3d{sub 5/2} energy levels as references. This implies a conduction band offset {Delta}E{sub C} of 2.39 eV in HfO{sub 2}/InGaZnO{sub 4} heterostructures and a nested interface band alignment.

Cho, Hyun [Department of Nanomechatronics Engineering, Pusan National University, Gyeongnam 627-706 (Korea, Republic of); Douglas, E. A.; Gila, B. P.; Craciun, V.; Lambers, E. S.; Pearton, S. J. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Ren Fan [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2012-01-02T23:59:59.000Z

187

Ge doped HfO{sub 2} thin films investigated by x-ray absorption spectroscopy  

SciTech Connect

The stability of the tetragonal phase of Ge doped HfO{sub 2} thin films on Si(100) was investigated. Hf(Ge)O{sub 2} films with Ge atomic concentrations varying from 0% to 15% were deposited by remote plasma chemical vapor deposition. The atomic structure on the oxide after rapid thermal annealing was investigated by x-ray absorption spectroscopy of the O and Ge K edges and by Rutherford backscattering spectrometry. The authors found that Ge concentrations as low as 5 at. % effectively stabilize the tetragonal phase of 5 nm thick Hf(Ge)O{sub 2} on Si and that higher concentrations are not stable to rapid thermal annealing at temperatures above 750 deg. C.

Miotti, Leonardo; Bastos, Karen P.; Lucovsky, Gerald; Radtke, Claudio; Nordlund, Dennis [Department of Physics, North Carolina State University, Box 8202, Raleigh, North Carolina 27695-8202 (United States); Instituto de Quimica, Universidade Federal do Rio Grande do Sul, 91509-900 Porto Alegre (Brazil); Stanford Synchrotron Radiation Lightsource, Menlo Park, California 94025 (United States)

2010-07-15T23:59:59.000Z

188

Fabrication and properties of ZrCZrB2/Ni cermet coatings on a magnesium alloy by atmospheric plasma spraying of SHS powders  

Science Journals Connector (OSTI)

Abstract ZrB2ZrC/Ni composite powders were successfully produced from a NiZrB4C system by self-propagating high-temperature synthesis (SHS), and ZrB2ZrC/Ni cermet coatings were deposited on a magnesium alloy substrate by atmospheric plasma spraying (APS) using the SHS-derived powders as feedstock powders. Microstructure and phase composition of the SHS powders and APS coatings were investigated by scanning electron microscopy and X-ray diffraction, respectively. Microhardness and wear resistance of the coatings were examined by using a Vickers hardness tester and pin-on-desk tribometer. The coatings exhibited lamellar and porous structure, mainly consisting of ZrB2, ZrC and Ni in addition to the by-product ZrO2. The coatings bonded well to the substrate with the bonding strength as high as 16.27MPa. Microhardness and wear resistance of the substrate were significantly improved by the coatings. The wear resistance of the coatings for the substrate initially increased and subsequently decreased with the increase in Ni content. The coating with 30wt% Ni in the feedstock powder displayed the highest microhardness of 525.0296.08 HV0.1 and the best wear resistance for the substrate.

Jiaying Xu; Binglin Zou; Sumei Zhao; Yu Hui; Wenzhi Huang; Xin Zhou; Ying Wang; Xiaolong Cai; Xueqiang Cao

2014-01-01T23:59:59.000Z

189

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

Energy.gov (U.S. Department of Energy (DOE))

Purpose, Context, Meeting Process, and Agenda for MW and RF as Enabling Technologies for Advanced Manufacturing on July 25, 2012

190

COMPUTATIONAL MODELING OF MUONS PASSING THROUGH GAS PRESSURED RF CAVITIES  

E-Print Network (OSTI)

of muons passing through matter. PHYSICAL MODEL We start our study with a classical scattering of muonsCOMPUTATIONAL MODELING OF MUONS PASSING THROUGH GAS PRESSURED RF CAVITIES A. Samolov, A. Godunov, and to validate a technical design of these new accelerating facilities, accu- rate and comprehensive simulations

Godunov, Alexander L.

191

Feedback Configuration Tools for LHC Low Level RF  

SciTech Connect

The LHC Low Level RF System (LLRF) is a complex multi-VME crate system which is used to regulate the superconductive cavity gap voltage as well as to lower the impedance as seen by the beam through low latency feedback. This system contains multiple loops with several parameters to be set before the loops can be closed. In this paper, we present a suite of MATLAB based tools developed to perform the preliminary alignment of the RF stations and the beginnings of a closed loop model based alignment routine. We briefly introduce the RF system and in particular the base band (time domain noise based) network analyzer system built into the LHC LLRF. The main focus of this paper is the methodology of the algorithms used by the routines within the context of the overall system. Measured results are presented that validate the technique. Because the RF systems are located in a cavern 120 m underground in a location which is relatively un-accessible without beam and completely un-accessible with beam present or magnets are energized, these remotely operated tools are a necessity for the CERN LLRF team to maintain and tune their LLRF systems in a similar fashion as to what was done very successfully in PEP-II at SLAC.

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

2009-12-16T23:59:59.000Z

192

COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: I. QUASILINEAR THEORY  

E-Print Network (OSTI)

COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: I. QUASILINEAR THEORY Yu.M. Aliev1 , I an interest in mechanisms of electron heating and power deposition in the plasma main- tained by radio parameters. Due to the large value of the mean free path (MFP) the main mechanism of electron heating turns

Kaganovich, Igor

193

RF power potential of 45 nm CMOS technology  

E-Print Network (OSTI)

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 ...

Putnam, Christopher

194

Electric Resistance Change Mechanism of Indium-Tin Oxide Film During Deposition of Dielectric Oxide Films by RF Magnetron Sputtering  

Science Journals Connector (OSTI)

Electric resistance change of indium-tin oxide (ITO) film was investigated when dielectric oxide films such as Sr(Zr0.2Ti0.8)O3 and Y2O3 for an electroluminescent device were deposited on the ITO by the rf magnetron sputtering method using oxide ceramic targets. In order to understand the mechanism of the resistance change, a dc voltage of -70~+70 V was biased to an ITO film during the sputtering of dielectric oxide films. The resistance of the ITO film became higher in the positive bias region. The cause of the increase in resistance of the ITO films was confirmed to be oxidation by the oxide targets and the sputtering gas. The amount of the resistance change could be qualitatively explained by the ratio of the oxygen introduced into the ITO film and the combined oxygen forming O2 gas at the ITO surface incident to the ITO film at the sputtering of the dielectric oxide films.

Tomizo Matsuoka; Jun Kuwata; Masahiro Nishikawa; Yosuke Fujita; Takao Tohda; Atsushi Abe

1988-01-01T23:59:59.000Z

195

Two-step behavior of initial oxidation at HfO{sub 2}/Si interface  

SciTech Connect

In situ x-ray photoelectron spectroscopy revealed that initial Si oxidation at the HfO{sub 2}/Si(001) interface in O{sub 2} proceeds in a two-step manner with an initial slow stage followed by a fast one. This transition in the oxidation process is most likely caused by crystallization of the HfO{sub 2} film. The first stage at 400-600 deg. C exhibited postdeposition annealing conditions suitable for suppressing the interfacial Si oxide in a monolayer region.

Miyata, Noriyuki [MIRAI, Advanced Semiconductor Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562 (Japan)

2006-09-04T23:59:59.000Z

196

Nb-Pb superconducting RF-gun TESLA-FEL Report 2005-09  

E-Print Network (OSTI)

Nb-Pb superconducting RF-gun TESLA-FEL Report 2005-09 J. Sekutowicz, J. Iversen, G. Kreps, W Sand Hill Road, Menlo Park, CA 94025, USA We report on the status of an electron RF-gun made of two superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead

197

Wi-fi backscatter: internet connectivity for RF-powered devices  

Science Journals Connector (OSTI)

RF-powered computers are small devices that compute and communicate using only the power that they harvest from RF signals. While existing technologies have harvested power from ambient RF sources (e.g., TV broadcasts), they require a dedicated gateway ... Keywords: backscatter, energy harvesting, internet of things, wireless

Bryce Kellogg, Aaron Parks, Shyamnath Gollakota, Joshua R. Smith, David Wetherall

2014-08-01T23:59:59.000Z

198

Multiband Antenna-Receiver Integration using an RF Multiplexer with Sensitivity-Constrained Design  

E-Print Network (OSTI)

S.M. Shajedul Hasan (hasan@vt.edu) Steven Ellingson (ellingson@vt.edu) RF Multiplexer Hasan be largely mitigated by: · Implementing design to be robust to variations RF Multiplexer Hasan / Ellingson #12;Motivation (2/2) Focus of this paper System Diagram of the prototype MMR RF Multiplexer Hasan

Ellingson, Steven W.

199

Multiband Antenna-Receiver Integration using an RF Multiplexer with Sensitivity-Constrained Design  

E-Print Network (OSTI)

S.M. Hasan and S. W. Ellingson Wireless at Virginia Tech RF Multiplexer Hasan / Ellingson ­ July 10 be largely mitigated by: 2/14 RF Multiplexer Hasan / Ellingson ­ July 10, 2008 RFIC from Motorola Research (2/2) Focus of this paper System Diagram of the prototype MMR 3/14 RF Multiplexer Hasan / Ellingson

Ellingson, Steven W.

200

Integration of LED chip within patch antenna geometry for hybrid FSO/RF communication  

E-Print Network (OSTI)

Integration of LED chip within patch antenna geometry for hybrid FSO/RF communication J. Liao, A mode communi- cation transmitter using a LED integrated within the geometry of a planar patch antenna the geometry of the patch antenna to create a miniaturised LED/RF package. The RF channel can either work

Huang, Zhaoran "Rena"

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Design of RF Feed System for Standing-Wave Accelerator Structures  

SciTech Connect

We are investigating a standing wave structure with an rf feed to each individual cell. This approach minimizes rf power flow and electromagnetic energy absorbed by an rf breakdown. The objective of this work is a robust high-gradient (above 100 MV/m) X-band accelerator structure.

Neilson, Jeffrey; Tantawi, Sami; Dolgashev, Valery [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

2010-11-04T23:59:59.000Z

202

Wear and friction behavior of Zr implanted D3 steel  

SciTech Connect

Multicharged, pure, high current and pulsed ion beams of Zr have been extracted from a metal vapor vacuum arc (MEVVA) source and implanted into AISI D3 (C: 2-2,35%, Mn: 0,60%, Si: 0,60%, Cr: 11-13,50%, Ni: 0,30%, W: 1%, V: 1%) tool steel samples at the 3,6.1016, 5.1016 and 1.1017 ions/cm2 doses. The wear resistance and friction coefficient have been estimated using pin-on-disc wear tests. Implantation of Zr decreased the wear loss and friction coefficient. RBS, AES and SEM Microprobe analyses were used as a guide for explanation of implantation's effects.

Akbas, N.; Saklakoglu, I.E.; Monteiro, O.R.; Brown, I.G.

2001-08-23T23:59:59.000Z

203

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

E-Print Network (OSTI)

High-power ELF radiation generated by modulated HF heating of the ionosphere can cause Earthquakes, the HAARP heater is the most powerful ionospheric heater, with 3.6GW of effective power using HF heating, Cyclones and localized heating Fran De Aquino Maranhao State University, Physics Department, S

Paris-Sud XI, Université de

204

Photoemission study of energy-band alignment for RuO{sub x}/HfO{sub 2}/Si system  

SciTech Connect

Conductive oxides RuO{sub x} as alternative electrode on high-{kappa} HfO{sub 2} gate dielectric have been fabricated by ultrahigh-vacuum sputtering and subsequently oxidized using oxygen plasma. The energy-band alignment for the RuO{sub x}/HfO{sub 2}/Si system and the oxidation-state dependence of barrier height for RuO{sub x} contacting to HfO{sub 2} dielectrics has been analyzed by x-ray photoemission spectroscopy. The valence- and conduction-band offsets of HfO{sub 2}/Si are determined to be 3.05{+-}0.1 and 1.48{+-}0.1 eV, respectively. The barrier heights for the RuO{sub x} contacting to HfO{sub 2} are oxidation-state dependent, in the range of 1.95-2.73 eV.

Li, Q.; Wang, S.J.; Li, K.B.; Huan, A.C.H.; Chai, J.W.; Pan, J.S.; Ong, C.K. [Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602 (Singapore); Data Storage Institute, DSI Building, 5 Engineering Drive 1, Singapore 117608 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, Singapore and Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore)

2004-12-20T23:59:59.000Z

205

Low-temperature method for enhancing sputter-deposited HfO{sub 2} films with complete oxidization  

SciTech Connect

A low-temperature method, supercritical CO{sub 2} fluid (SCF) technology, is proposed to improve the dielectric properties of ultrathin hafnium oxide (HfO{sub 2}) film at 150 deg. C without significant formation of parasitic oxide at the interface between HfO{sub 2} and Si substrate. In this research, the HfO{sub 2} films were deposited by dc sputter at room temperature and post-treated by SCF which is mixed with 5 vol % propyl alcohol and 5 vol % H{sub 2}O. From high-resolution transmission electron microscopy image, the interfacial oxide of SCF-treated HfO{sub 2} film is only 5 A ring thick. Additionally, the enhancements in the qualities of sputter-deposited HfO{sub 2} film after SCF process are exhibited by x-ray photoelectron spectroscopy and capacitance-voltage (C-V) measurement.

Tsai, C.-T.; Chang, T.-C.; Liu, P.-T.; Yang, P.-Y.; Kuo, Y.-C.; Kin, K.-T.; Chang, P.-L.; Huang, F.-S. [Institute of Electronics Engineering, National Tsing Hua University, HsinChu 300, Taiwan (China); Department of Physics and Institute of Electro-Optical Engineering, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung 804, Taiwan (China); Department of Photonics and Display Institute, National Chiao Tung University, 1001 Ta-Hsueh Rd., HsinChu 300, Taiwan (China); Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 300, Taiwan (China); Institute of Electronics Engineering, National Tsing Hua University, HsinChu 300, Taiwan (China)

2007-07-02T23:59:59.000Z

206

E-Print Network 3.0 - application zr-sn alloys Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

used... , Zr, Sn, ... Source: Zheng, Yufeng - Department of Advanced Materials and Nanotechnology, Peking University Collection: Materials Science ; Biology and Medicine 2...

207

The Development of the Linac Coherent Light Source RF Gun  

SciTech Connect

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.

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

2008-09-24T23:59:59.000Z

208

MicroPlanet Technology Corp formerly HF Capital Corp | Open Energy  

Open Energy Info (EERE)

Technology Corp formerly HF Capital Corp Technology Corp formerly HF Capital Corp Jump to: navigation, search Name MicroPlanet Technology Corp (formerly HF Capital Corp) Place Seattle, Washington Zip 98104 Sector Efficiency Product MicroPlanet develops energy-efficiency products for homes and small businesses. Specifically they focus on custom voltage regulators that result in energy savings. On May 6, 2005, the company reverse-listed into Toronto Venture Exchange quoted HF Capital. Coordinates 47.60356°, -122.329439° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":47.60356,"lon":-122.329439,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

209

High-spin excitations in 158,159,160 Hf from recoil-decay tagging  

E-Print Network (OSTI)

Argonne National Laboratory, Argonne, Illinois 60439 3 Nuclear Science Division, Lawrence Berkeley coupled to the Fragment Mass Analyzer at Argonne National Laboratory. Level structures of 158 Hf and 159 technique at Argonne National Laboratory. These reactions have a large number of particle

210

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

E-Print Network (OSTI)

;Abstract The radio spectrum between 300 Hz and 10 kHz (ELF/VLF) has broad applications to global (HF, 3-10 MHz) heating of the lower ionosphere (60-100 km altitude), which changes the atmospheric plasma conductivity. In the presence of natural currents such as the auroral electrojet, ON

211

Scanning tunneling microscopy study of nitrogen incorporated HfO{sub 2}  

SciTech Connect

The impact of nitrogen incorporation on the physical and electrical characteristics of the HfO{sub 2} is examined. X-ray photoelectron spectroscopy shows that nitrogen can be incorporated into the HfO{sub 2} via a two-step thermal anneal--first in ultrahigh vacuum (UHV) and subsequently in N{sub 2}. Following the N{sub 2} anneal, scanning tunneling microscopy in UHV reveals a marked reduction in the low-voltage leakage current under gate injection biasing. From band theory and existing first-principles simulation results, one may consistently attribute this improvement to the passivation of oxygen vacancies in the HfO{sub 2} by nitrogen. Improvement in the breakdown strength of the HfO{sub 2} subjected to ramp-voltage stress (substrate injection) is also observed after the N{sub 2} anneal. The local current-voltage curves acquired concurrently during the ramp-voltage stress exhibit 'space-charge limited conduction', which implies that the observed improvement in breakdown strength may be related to a limitation of the current flow through the gate stack in the high stress voltage regime.

Ong, Y. C.; Ang, D. S.; Pey, K. L.; Li, X. [Nanyang Technological University, School of Electrical and Electronic Engineering, Nanyang Avenue, Singapore 639798 (Singapore); O'Shea, S. J.; Wang, S. J. [Institute of Materials Research and Engineering, A-STAR - Agency for Science, Technology and Research, 3 Research Link, Singapore 11760 (Singapore); Tung, C. H. [Institute of Microelectronics, A-STAR - Agency for Science, Technology and Research, 11 Science Park Road, Singapore Science Park II, Singapore 117685 (Singapore)

2008-09-15T23:59:59.000Z

212

Metal-gate-induced reduction of the interfacial layer in Hf oxide gate stacks  

SciTech Connect

The properties of high-{kappa} metal oxide gate stacks are often determined in the final processing steps following dielectric deposition. We report here results from medium energy ion scattering and x-ray photoelectron spectroscopy studies of oxygen and silicon diffusion and interfacial layer reactions in multilayer gate stacks. Our results show that Ti metallization of HfO{sub 2}/SiO{sub 2}/Si stacks reduces the SiO{sub 2} interlayer and (to a more limited extent) the HfO{sub 2} layer. We find that Si atoms initially present in the interfacial SiO{sub 2} layer incorporate into the bottom of the high-{kappa} layer. Some evidence for Ti-Si interdiffusion through the high-{kappa} film in the presence of a Ti gate in the crystalline HfO{sub 2} films is also reported. This diffusion is likely to be related to defects in crystalline HfO{sub 2} films, such as grain boundaries. High-resolution transmission electron microscopy and corresponding electron energy loss spectroscopy scans show aggressive Ti-Si intermixing and oxygen diffusion to the outermost Ti layer, given high enough annealing temperature. Thermodynamic calculations show that the driving forces exist for some of the observed diffusion processes.

Goncharova, L. V.; Dalponte, M.; Gustafsson, T.; Celik, O.; Garfunkel, E.; Lysaght, P. S.; Bersuker, G. [Department of Physics and Astronomy, and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Rd., Piscataway, New Jersey 08854 (United States); Department of Chemistry and Chemical Biology, and Laboratory for Surface Modification, Rutgers University, 610 Taylor Rd., Piscataway, New Jersey 08854 (United States); SEMATECH, 2705 Montopolis Dr., Austin, Texas 78741 (United States)

2007-03-15T23:59:59.000Z

213

Investigation of HF plasma turbulence excitation and dissipation in the vicinity of 5th  

E-Print Network (OSTI)

of stimulated electromagnetic emission (SEE) of the ionosphere pumped by powerful HF radio waves are presented, Uppsala Division, SE-751 21 Uppsala, Sweden Experimental results on development and relaxation times after PW turn off d 0.7­1.0 ms are 2­4 times faster than collisional ones for the Langmuir waves

214

Oxygen diffusion and reactions in Hf-based dielectrics L. V. Goncharova,a  

E-Print Network (OSTI)

Oxygen diffusion and reactions in Hf-based dielectrics L. V. Goncharova,a M. Dalponte, D. G Oxygen transport in and reactions with thin hafnium oxide and hafnium silicate films have been. The exchange rate is faster for pure hafnium oxides than for silicates. The amount of exchanged oxygen

Gustafsson, Torgny

215

rf power system for thrust measurements of a helicon plasma source  

SciTech Connect

A rf power system has been developed, which allows the use of rf plasma devices in an electric propulsion test facility without excessive noise pollution in thruster diagnostics. Of particular importance are thrust stand measurements, which were previously impossible due to noise. Three major changes were made to the rf power system: first, the cable connection was changed from a balanced transmission line to an unbalanced coaxial line. Second, the rf power cabinet was placed remotely in order to reduce vibration-induced noise in the thrust stand. Finally, a relationship between transmission line length and rf was developed, which allows good transmission of rf power from the matching network to the helicon antenna. The modified system was tested on a thrust measurement stand and showed that rf power has no statistically significant contribution to the thrust stand measurement.

Kieckhafer, Alexander W.; Walker, Mitchell L. R. [Department of Aerospace Engineering, High-Power Electric Propulsion Laboratory, College of Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2010-07-15T23:59:59.000Z

216

Control of silicidation in HfO2/Si,,100... interfaces Deok-Yong Cho, Kee-Shik Park, B.-H. Choi,a  

E-Print Network (OSTI)

like nitrogen.6,7 Among these, Hf-silicide is probably most detrimental since it is metallic and degrades the capacitor performance. Metal- lic Hf-silicide formation has been reported in the interfaceControl of silicidation in HfO2/Si,,100... interfaces Deok-Yong Cho, Kee-Shik Park, B.-H. Choi

Oh, Se-Jung

217

Performance of Magnesium Cathode in the S Band RF Gun  

SciTech Connect

In this paper, we present the preliminary results of the performance of magnesium cathode in a high frequency RF gun. The quantum efficiency of magnesium showed a dramatic improvement upon laser cleaning, increasing from 10{sup -5} to 4x10{sup -4} after two hours of cleaning. The spatial uniformity of emission also improved from a spot to spot variation of 10 to a variation of 2. Measurements with charges >1 nC indicate that the transient variation of the field due to the shielding effect of the electron in the vicinity of the cathode may play a critical role in the efficient extraction of electrons. Comprehensive theory that includes the electron emission in the presence of a time dependent Schottky effect and RF effects will be discussed.

Srinivasan-Rao, T.; /Brookhaven; Palmer, D.T.; /SLAC; Ben-Zvi, I.; /Brookhaven; Miller, R.H.; /SLAC; Wang, X.J.; Woodle, M.; /Brookhaven

2011-09-01T23:59:59.000Z

218

RF generation in the DARHT Axis-II beam dump  

SciTech Connect

We have occasionally observed radio-frequency (RF) electromagnetic signals in the downstream transport (DST) of the second axis linear induction accelerator (LIA) at the dual-axis radiographic hydrodynamic testing (DARHT) facility. We have identified and eliminated some of the sources by eliminating the offending cavities. However, we still observe strong RF in the range 1 GHz t0 2 GHz occurring late in the {approx}2-{micro}s pulse that can be excited or prevented by varying the downstream tune. The narrow frequency width (<0.5%) and near exponential growth at the dominant frequency is indicative of a beam-cavity interaction, and electro-magnetic simulations of cavity structure show a spectrum rich in resonances in the observed frequency range. However, the source of beam produced RF in the cavity resonance frequency range has not been identified, and it has been the subject of much speculation, ranging from beam-plasma or beam-ion instabilities to unstable cavity coupling.

Ekdahl, Carl A. Jr. [Los Alamos National Laboratory

2012-05-03T23:59:59.000Z

219

HIGH-POWER RF DISTRIBUTION SYSTEMFOR THE 8-PACK PROJECT  

SciTech Connect

The 8-Pack Project at SLAC is a prototype rf system whose goal is to demonstrate the high-power X-band technology developed in the NLC/GLC (Next/Global Linear Collider) program. In its first phase, it has reliably produced a 400 ns rf pulse of over 500 MW using a solidstate modulator, four 11.424 GHz klystrons and a dualmoded SLED-II pulse compressor. In Phase 2, the output power of the system has been delivered into the bunker of the NLCTA (Next Linear Collider Test Accelerator) and divided between several accelerator structures for beam acceleration. The authors describe here the design, cold-test measurements, and processing of this power distribution system. Due to the high power levels and the need for efficiency, overmoded waveguide and components are used. For power transport, the TE{sub 01} mode is used in 7.44 cm and 4.064 cm diameter circular waveguide. Only near the structures is standard WR90 rectangular waveguide employed. Components used to manipulate the rf power include transitional tapers, mode converters, overmoded bends, fractional directional couplers, and hybrids.

Nantista, C

2004-08-24T23:59:59.000Z

220

Nitrogen Doping and Thermal Stability in HfSiOxNy Studied by Photoemission and X-ray Absorption Spectroscopy  

SciTech Connect

We have investigated nitrogen-doping effects into HfSiO{sub x} films on Si and their thermal stability using synchrotron-radiation photoemission and x-ray absorption spectroscopy. N 1s core-level photoemission and N K-edge absorption spectra have revealed that chemical-bonding states of N-Si{sub 3-x}O{sub x} and interstitial N{sub 2}-gas-like features are clearly observed in as-grown HfSiO{sub x}N{sub y} film and they decrease upon ultrahigh vacuum (UHV) annealing due to a thermal instability, which can be related to the device performance. Annealing-temperature dependence in Hf 4f and Si 2p photoemission spectra suggests that the Hf-silicidation temperature is effectively increased by nitrogen doping into the HfSiO{sub x} although the interfacial SiO{sub 2} layer is selectively reduced. No change in valence-band spectra upon UHV annealing suggests that crystallization of the HfSiO{sub x}N{sub y} films is also hindered by nitrogen doping into the HfSiO{sub x}.

Toyoda, Satoshi; Okabayashi, Jun; Takahashi, Haruhiko; Oshima, Masaharu; /Tokyo U.; Lee, Dong-Ick; Sun, Shiyu; sun, Steven; Pianetta, Piero A.; /SLAC, SSRL; Ando, Takashi; Fukuda, Seiichi; /SONY, Atsugi

2005-12-14T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Interfacial reaction induced phase separation in La{sub x}Hf{sub y}O films  

SciTech Connect

Amorphous La{sub x}Hf{sub y}O films containing La at concentrations (x) of 50 and 20% were prepared by atomic layer deposition on ultrathin SiO{sub 2} films (1 nm). We examined the electronic structures and microstructures of the La{sub x}Hf{sub y}O films by x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD). Phase separation into La{sub 2}O{sub 3} and HfO{sub 2} was observed in the La{sub x}Hf{sub y}O films subjected to annealing temperatures over 900 deg. C, although the mixture of La{sub 2}O{sub 3} and HfO{sub 2} is thermodynamically stable. The structural changes that occurred as the result of phase separation were dependent on the concentrations of La and Hf in the films. During the annealing treatment, silicate was produced due to interfacial reactions and the interfacial reactions were found to be dependent on the La{sub 2}O{sub 3} content in the La{sub x}Hf{sub y}O films, which has a significant influence on the phase separation process and resulting film structure.

Ma, J. W.; Lee, W. J.; Cho, M.-H. [Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, K. M.; Sohn, H. C. [Department of Material Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, C. S. [Korea Research Institute of Standards and Science, Daejeon 305-540 (Korea, Republic of); Cho, H. J. [Process Development Team, Semiconductor R and D Center, Samsung Electronics Co., LTD, Gyeonggi-Do 449-711 (Korea, Republic of)

2011-06-15T23:59:59.000Z

222

A low temperature fabrication of HfO{sub 2} films with supercritical CO{sub 2} fluid treatment  

SciTech Connect

To improve the dielectric properties of sputter-deposited hafnium oxide (HfO{sub 2}) films, the supercritical CO{sub 2} (SCCO{sub 2}) fluid technology is introduced as a low temperature treatment. The ultrathin HfO{sub 2} films were deposited on p-type (100) silicon wafer by dc sputtering at room temperature and subsequently treated with SCCO{sub 2} fluids at 150 deg. C to diminish the traps in the HfO{sub 2} films. After SCCO{sub 2} treatment, the interfacial parasitic oxide between the Si substrate and HfO{sub 2} layer is only about 5 A, and the oxygen content of the HfO{sub 2} films apparently increased. From current-voltage (I-V) and capacitance-voltage (C-V) measurements, the leakage current density of the SCCO{sub 2}-treated HfO{sub 2} films is repressed from 10{sup -2} to 10{sup -7} A/cm{sup 2} at electric field=3 MV/cm due to the reduction of traps in the HfO{sub 2} films. The equivalent oxide thickness also obviously decreased. Besides, the efficiency of terminating traps is relative to the pressure of the SCCO{sub 2} fluids.

Tsai, C.-T.; Huang, F.-S. [Institute of Electronics Engineering, National Tsing Hua University, HsinChu 300, Taiwan (China); Chang, T.-C. [Department of Physics, Center for Nanoscience and Nanotechnology, National Sun Yat-set University, 70 Lien-hai Road, Kaohsiung 804, Taiwan (China); Institute of Electro-Optical Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China); Kin, K.-T. [Industrial Technology Research Institute-Energy and Environment Research Laboratories, Hsinchu 300, Taiwan (China); Liu, P.-T.; Yang, P.-Y. [Department of Photonics and Display Institute, National Chiao Tung University, Hsinchu 300, Taiwan (China); Weng, C.-F. [Department of Physics, Center for Nanoscience and Nanotechnology, National Sun Yat-set University, 70 Lien-hai Road, Kaohsiung 804, Taiwan (China)

2008-04-01T23:59:59.000Z

223

Structural properties of amorphous carbon thin films deposited by LF (100 kHz), RF (13.56 MHz), and pulsed RF (13.56 MHz) plasma CVD  

Science Journals Connector (OSTI)

Amorphous carbon thin films were deposited by LF (100 kHz), RF (13.56 MHz), and pulsed RF (13.56 MHz) plasma CVD with DC self-bias voltage of? ... properties of the deposited films in an asymmetric plasma reactor...

Dong-Sun Kim

2005-07-01T23:59:59.000Z

224

1 -SUBTIDAL 2 -INTERTIDAL RB ROCK UB UNCONSOLIDATED AB AQUATIC BED RF -REEF OW -OPEN WATER/ AB AQUATIC BED RF REEF RS ROCKY SHORE US -UNCONSOLIDATED  

E-Print Network (OSTI)

M - MARINE 1 - SUBTIDAL 2 - INTERTIDAL RB ­ ROCK UB ­ UNCONSOLIDATED AB ­ AQUATIC BED RF - REEF OW - OPEN WATER/ AB ­ AQUATIC BED RF­ REEF RS ­ ROCKY SHORE US - UNCONSOLIDATED BOTTOM BOTTOM Unknown Bottom ­ UNCONSOLIDATED AB ­ AQUATIC RF ­ REEF OW - OPEN WATER/ AB ­ AQUATIC RF­ REEF SB ­ STREAMBED RS - ROCKY US

Gray, Matthew

225

Site preferences of indium impurity atoms in intermetallics having Al3Ti and Al3Zr crystal structures  

E-Print Network (OSTI)

Site preferences of indium impurity atoms in intermetallics having Al3Ti and Al3Zr crystal-04843 (Metals Program) and Praveen Sinha Fund for Physics Research. L12 DO22 DO23 Cu3Au Al3Ti Al3Zr #12;Outline · Indium was doped in samples of Al3V and Al3Ti (Al3Ti structure) and Al3Zr (Al3Zr structure) by arc

Collins, Gary S.

226

Atomistic Studies of Cation Transport in Tetragonal ZrO2 During Zirconium Corrosion  

SciTech Connect

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.

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

2013-10-01T23:59:59.000Z

227

ZrO sub 2 reinforced-MoSi sub 2 matrix composites  

SciTech Connect

ZrO{sub 2} particle-MoSi{sub 2} matrix composites were fabricated by wet processing/hot pressing, using high quality unstabilized, partially stabilized, and fully stabilized ZrO{sub 2} powders. Composite room temperature indentation fracture toughness increased with increasing volume fraction of ZrO{sub 2} reinforcement. Unstabilized ZrO{sub 2} produced the highest composite fracture toughness, 7.8 MPa m{sup {1/2}} as compared to 2.6 MPa m{sup {1/2}} for pure MoSi{sub 2}. Unstabilized ZrO{sub 2} composites exhibited matrix microcracking, and the spontaneous tetragonal-to-monoclinic ZrO{sub 2} phase transformation induced significant plastic deformation in the MoSi{sub 2} matrix. Partially stabilized ZrO{sub 2} produced a lesser extent of composite fracture toughening, possibly as a result of an inhomogeneous ZrO{sub 2} particle distribution and presence of a glassy phase. 13 refs., 6 figs., 1 tab.

Petrovic, J.J.; Honnell, R.E.; Mitchell, T.E. (Los Alamos National Lab., NM (USA)); Wade, R.K. (Arizona Materials Lab., Tucson, AZ (USA)); McClellan, K.J. (Case Western Reserve Univ., Cleveland, OH (USA). Dept. of Materials Science and Engineering)

1991-01-01T23:59:59.000Z

228

Direct mass measurements of neutron-rich zirconium isotopes up to Zr104  

Science Journals Connector (OSTI)

Atomic masses of radioactive zirconium isotopes from Zr96 to Zr104 have been measured with a relative accuracy of ?510?7 using a Penning trap coupled to the ion guide isotope separator on-line system. The obtained two-neutron separation energies show strong local correlation in relation to the shape change and shape coexistence between N=58 and 60.

S. Rinta-Antila; S. Kopecky; V. S. Kolhinen; J. Hakala; J. Huikari; A. Jokinen; A. Nieminen; J. yst; J. Szerypo

2004-07-14T23:59:59.000Z

229

E-Print Network 3.0 - as-cast zr ti Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

page cl-733 Summary: par ajout de ZrOz(Y20,) e t de matdriaux monoxydes t e l s que Sic, Tic, TiN e t B4C. Un renforcement... 304 344 247 344 Composite A120,-ZrO,OY-TiN...

230

Transformation plasticity and thermoelastic behavior in ZrO2-containing ceramics  

E-Print Network (OSTI)

565 Transformation plasticity and thermoelastic behavior in ZrO2-containing ceramics A. H. Heuer plasticité de transformation dans ZrO2, qui est responsable de la ré- sistance mécanique et de la grande profit. Dans certaines conditions, cette transformation est réversible, autocatalytique et

Paris-Sud XI, Université de

231

Abrasive wear of ZrB2-containing spark-deposited and combined coatings on titanium alloy. I. microstructure and composition of ZrB2-containing coatings  

Science Journals Connector (OSTI)

To improve the abrasive wear resistance of titanium alloys, ZrB2-containing protective coatings are deposited by electrospark alloying (ESA). As electrode materials, composite ceramics with different amounts of Z...

I. A. Podchernyaeva; A. D. Panasyuk

2009-05-01T23:59:59.000Z

232

Effect of high-energy milling on hydrogen desorption and the structure of mixtures of Zr-containing materials  

Science Journals Connector (OSTI)

Mass-spectrometric investigations of hydrogen liberation from the mixture of powders 3ZrO0.2Hx + ZrFe2, the overall composition of which corresponds to Zr4Fe2O0.6Hx, after its treatment by ball milling for 5 and ...

I. Yu. Zavalii; M. Yurchyk; O. M. Vovk; I. V. Saldan; I. V. Kovalchuk

2005-11-01T23:59:59.000Z

233

Combustion Processes in the Zr-Co-H2 System and Synthesis of Hydrides of Intermetallic Compounds  

Science Journals Connector (OSTI)

The researches on Zr2Co, ZrCo, ZrCo2 synthesis and hydriding in a self-propagating hightemperature synthesis SHS mode are carried out. In IMC hydrogen systems low temperature (350500C) and high temperature ...

H. G. Hakobyan; S. K. Dolukhanyan

2002-01-01T23:59:59.000Z

234

ZrO sub 2 and ZrO sub 2 /SiC particle reinforced-MoSi sub 2 matrix composites  

SciTech Connect

ZrO{sub 2}-MoSi{sub 2} and ZrO{sub 2}/SiC-MoSi{sub 2} composites were fabricated by hot pressing and hot pressing/HIP at 1700{degrees}C. No reactions between ZrO{sub 2}, SiC, and MoSi{sub 2} were observed. An amorphous silica glassy phase was present in all composites. Composites with unstabilized ZrO{sub 2} particles exhibited the highest room temperature fracture toughness, reaching a level three times that of pure MoSi{sub 2}. Both the room temperature toughness and 1200{degrees}C strength of ZrO/{sub 2}SiC-MoSi{sub 2} composites were higher than ZrO{sub 2}-MoSi{sub 2} composites, indicating beneficial effects of combined reinforcement phases. Low strength levels were observed at 1400{degrees}C due to the presence of the silica glassy phase. Elimination of glassy phases and refinements in microstructural homogeneity are processing routes important to the optimization of the mechanical properties of these types of composites. 18 refs., 7 figs.

Petrovic, J.J.; Bhattacharya, A.K.; Honnell, R.E.; Mitchell, T.E. (Los Alamos National Lab., NM (United States)); Wade, R.K. (Arizona Materials Lab., Tucson, AZ (United States)); McCellan, K.J. (Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering)

1991-01-01T23:59:59.000Z

235

Development of an RF Conditioning System for Charged-Particle Accelerators  

SciTech Connect

Charged-particle accelerators use various vacuum windows on their accelerating radio-frequency (RF) cavities to throughput very high RF power. Before being placed on the cavities, the windows should be cleaned, baked, and fully RF conditioned to prevent a poor vacuum from outgassing, as well as other forms of contamination. An example is the coaxial fundamental power coupler (FPC) with an annular alumina ceramic window for each of the 81 superconducting RF cavities in the Spallation Neutron Source (SNS) linear accelerator. The FPCs needed to be tested up to 650-kW peak in a traveling wave and 2.6 MW with standing wave peaks in 1.3 and 60 pulses/s at 805 MHz. In this paper, an Experimental-Physics-and-Industrial-Control-System-based RF conditioning system for the SNS RF test facility is presented. This paper summarizes the hardware and software design strategies, provides the results obtained, and describes the future research scope.

Kang, Yoon W [ORNL; Howlader, Mostofa [ORNL; Shajedul Hasan, Dr. S. M. [Virginia Polytechnic Institute and State University (Virginia Tech)

2008-01-01T23:59:59.000Z

236

EFFECT OF AGING ON THE PHASE TRANSFORMATION AND MECHANICAL BEHAVIOR OF Ti36Ni49Hf15 HIGH  

E-Print Network (OSTI)

and Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China (Received August 19 the microstructure, transformation temperature, mechanical properties and shape memory effects (SMEs) for Ti36Ni49Hf

Zheng, Yufeng

237

Human Factors Process Failure Mode and Effects Analysis (HF PFMEA) Application in the Evaluation of Management Risks  

E-Print Network (OSTI)

.3.1. Mechanisms of Prevention ............................................................................................... 11 2.4. Human Factors Process Failure Mode and Effects Analysis (HF PFMEA) ....................... 11 2.5. FMEA Components... ........................................................................................... 15 2.5.5. Risk Priority Number ....................................................................................................... 17 2.6. FMEA Model...

Soguilon, Nenita M.

2009-12-18T23:59:59.000Z

238

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

SciTech Connect

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.

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)

2014-01-14T23:59:59.000Z

239

Initial phases in sputter deposited HfO{sub 2}-Al{sub 2}O{sub 3} nanolaminate films  

SciTech Connect

Nanolaminate films of crystalline HfO{sub 2} and amorphous Al{sub 2}O{sub 3} were grown by reactive sputter deposition on unheated fused SiO{sub 2} and the surface oxide of <111> Si. X-ray diffraction showed the amount of monoclinic (m) HfO{sub 2} decreased with decreasing HfO{sub 2} layer thickness, consistent with a finite crystal size effect. High resolution transmission electron microscopy of individual crystallites detected tetragonal (t) and orthorhombic (o) HfO{sub 2} as the initial phases formed. Whereas the t{yields}m transition is accomplished by a shear mechanism, we demonstrate the important role of polysynthetic twinning for the o{yields}m transition.

Hoppe, E. E.; Aita, C. R.; Gajdardziska-Josifovska, M. [Advanced Coatings Experimental Laboratory, University of Wisconsin-Milwaukee, P.O. Box 784, Milwaukee, Wisconsin 53201 (United States); Department of Physics and Laboratory for Surface Studies, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201 (United States)

2007-11-12T23:59:59.000Z

240

Enhanced electrical characteristics of Au nanoparticles embedded in high-k HfO{sub 2} matrix  

SciTech Connect

We present experimental results for laser-induced Au nanoparticle (NP) embedded in a HfO{sub 2} high-k dielectric matrix. Cross-sectional transmission electron microscopy images showed that the Au NPs of 8 nm in diameter were clearly embedded in HfO{sub 2} matrix. Capacitance-voltage measurements of Pt/HfO{sub 2}/Au NPs/HfO{sub 2} on p-type Si substrate reliably exhibited metal-oxide-semiconductor behavior with a large flatband shift of 4.7 V. In addition, the charge retention time at room temperature was found to exceed 10{sup 5} h. This longer time was attributed to the higher electron barrier height via high work function of the Au NP.

Yang, Jung Yup; Kim, Ju Hyung; Choi, Won Joon; Do, Young Ho; Kim, Chae Ok; Hong, Jin Pyo [New Functional Materials and Devices Laboratory, Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of)

2006-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Reversed spin polarization at the Co(001)-HfO2(001) interface  

Science Journals Connector (OSTI)

Ab initio electronic-structure calculations on the Co(001)-HfO2(001) interface are reported. The spin polarization of conduction electrons is positive at the interface, i.e., it is reversed with respect to the spin polarization in bulk Co. The electronic structure is very sensitive to the interface structure; without atomic relaxations the reversed spin polarization is not found. The possible relation with spin-polarized tunneling and magnetoresistance is discussed.

P. K. de Boer; G. A. de Wijs; R. A. de Groot

1998-12-15T23:59:59.000Z

242

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

DOE Patents (OSTI)

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.

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

2013-01-15T23:59:59.000Z

243

Production and decay properties of the 1.9-s isomeric state in {sup 261}Rf  

SciTech Connect

The 1.9-s isomeric state ({sup 261}Rf{sup b}) in {sup 261}Rf was directly populated in the {sup 248}Cm({sup 18}O,5n){sup 261}Rf{sup b} reaction. Alpha and spontaneous fission (SF) decays of {sup 261}Rf{sup b}, as well as the 68-s state {sup 261}Rf{sup a}, was investigated with a rotating wheel apparatus under low background conditions attained by a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator. An identification of {sup 261}Rf{sup b} was based on {alpha}-{alpha} correlations linking {alpha} decays of {sup 261}Rf{sup b} and its daughter {sup 257}No. The {alpha}-particle energy of {sup 261}Rf{sup b} was measured to be 8.52 {+-} 0.05 MeV. The half-life was determined to be 1.9 {+-} 0.4 s based on both 8.52-MeV {alpha} and SF decays. The {alpha} and SF branches are 0.27 {+-} 0.06 and 0.73 {+-} 0.06, respectively. The cross section for the {sup 248}Cm({sup 18}O,5n){sup 261}Rf{sup b} reaction is {sigma}({sup 261}Rf{sup b}) = 11 {+-} 2 nb at 95.1 MeV, which gives a cross-section ratio of {sigma}({sup 261}Rf{sup a})/{sigma}({sup 261}Rf{sup b}) = 1.1 {+-} 0.2.

Haba, H.; Kaji, D.; Kikunaga, H.; Kudou, Y.; Morimoto, K.; Morita, K.; Ozeki, K.; Sumita, T.; Yoneda, A.; Kasamatsu, Y.; Komori, Y.; Ooe, K.; Shinohara, A. [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2011-03-15T23:59:59.000Z

244

Reactive ion beam etching of HfO{sub 2} film and removal of sidewall redeposition  

SciTech Connect

Comparative studies on ion beam etching (IBE) and reactive ion beam etching (RIBE) of HfO{sub 2} film have been carried out using photoresist as the masking layer. The etching rates of HfO{sub 2} film and photoresist mask in pure Ar and Ar/CHF{sub 3} mixture plasmas were measured as a function of ion energy, plasma composition, and ion beam incident angle. It has been found that the RIBE with Ar/CHF{sub 3} plasma is capable of lowering the threshold energy of ion beam and increasing sputtering yield, compared to the IBE with pure Ar. The redeposition of photoresist sidewall is a major issue, due to the formation of nonvolatile etching products during sputtering of HfO{sub 2} film in both IBE and RIBE. However, the sidewall redeposition can be easily removed in HCl solutions with assistance of ultrasonic wave for RIBE with Ar/CHF{sub 3} plasma. Alternatively, the sidewall redeposition can be eliminated by controlling the slope of photoresist sidewall or combined with ion incident angle.

Wang Xudi; Liu Ying; Xu Xiangdong; Fu Shaojun; Cui Zheng [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China) and School of Mechanical and Automobile Engineering, Hefei University of Technology, Hefei 230009 (China); National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Central Microstructure Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom)

2006-07-15T23:59:59.000Z

245

Gate Metal-Induced Diffusion and Interface Reactions in Hf Oxide Films on Si  

SciTech Connect

When metal electrodes are deposited on a high-{kappa} metal-oxide/SiO{sub 2}/Si stack, chemical interactions may occur both at the metal/high-{kappa} and the high-{kappa}/Si interfaces, causing changes in electrical performance. We report here results from medium energy ion scattering (MEIS) and x-ray photoelectron (XPS) studies of oxygen and silicon transport and interfacial layer reactions in multilayer gate stacks. Our results show that Ti deposition on HfO{sub 2}/SiO{sub 2}/Si stacks causes reduction of the SiO{sub 2} interfacial layer and (to a lesser extent) the HfO{sub 2} layer. Silicon atoms initially present in the interfacial SiO{sub 2} layer incorporate into the bottom of the high-{kappa} layer. Some evidence for titanium-silicon interdiffusion through the high-{kappa} film in the presence of a titanium gate in crystalline HfO{sub 2} films is also reported.

Goncharova, Lyudmila V.; Dalponte, Mateus; Celik, Ozgur; Garfunkel, Eric; Gustafsson, Torgny [Departments of Physics and Chemistry, and Laboratory for Surface Modification, Rutgers University, Piscataway, NJ 08854 (United States); Lysaght, Pat S.; Bersuker, Gennadi I. [Sematech, Austin, Texas 78741 (United States)

2007-09-26T23:59:59.000Z

246

Phase stability and elastic properties of C15 compounds HfV{sub 2}+Nb  

SciTech Connect

The ternary phase diagram of Hf-V-Nb system has been established and the C15 and C14 Laves phase regions located. The structural stability of the cubic Laves phase HfV{sub 2}+Nb was examined using heat capacity measurements and transmission electron microscopy. It is found that the binary C 15 has a martensitic transformation at 115K and that Nb addition can eliminate the martensitic transformation and stabilize the C15 structure. The elastic properties vs. temperature of the C15 HfV{sub 2}+Nb were studied using the resonant ultrasound technique. It is observed that the shear and Young`s moduli increase abnormally with increasing temperature, the bulk modulus is virtually constant, and the Poisson`s ratio is very high and decreases abnormally with increasing temperature. The elastic properties of the C15 compound can be qualitatively understood using the electronic structure obtained from ab initio calculations. The relation between the phase stability and anomalous elastic properties is discussed based on these results.

Chu, F.; Mitchell, T.E. [Los Alamos National Lab., NM (United States); Pope, D.P. [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Materials Science and Engineering

1994-10-01T23:59:59.000Z

247

Impact of titanium addition on film characteristics of HfO{sub 2} gate dielectrics deposited by atomic layer deposition  

SciTech Connect

The impact of 8-to 45-at. % Ti on physical and electrical characteristics of atomic-layer-deposited and annealed hafnium dioxide was studied using vacuum-ultraviolet spectroscopic ellipsometry, secondary ion mass spectroscopy, transmission electron microscopy, atomic force microscopy, x-ray diffraction, Rutherford backscattering spectroscopy, x-ray photoelectron spectroscopy, and x-ray reflectometry. The role of Ti addition on the electrical performance is investigated using molybdenum (Mo)-gated capacitors. The film density decreases with increasing Ti addition. Ti addition stabilizes the amorphous phase of HfO{sub 2}, resulting in amorphous films as deposited. After a high-temperature annealing, the films transition from an amorphous to a polycrystalline phase. Orthorhombic Hf-Ti-O peaks are detected in polycrystalline films containing 33-at. % or higher Ti content. As Ti content is decreased, monoclinic HfO{sub 2} becomes the predominant microstructure. No TiSi is formed at the dielectric/Si interface, indicating films with good thermal stability. The band gap of Hf-Ti-O was found to be lower than that of HfO{sub 2}. Well-behaved capacitance-voltage and leakage current density-voltage characteristics were obtained for Hf-Ti-O. However, an increased leakage current density was observed with Ti addition. The data from capacitance-voltage stressing indicate a smaller flatband voltage (V{sub fb}) shift in the HfO{sub 2} films with low Ti content when compared with the HfO{sub 2} films. This indicates less charge trapping with a small amount of Ti addition.

Triyoso, D.H.; Hegde, R.I.; Zollner, S.; Ramon, M.E.; Kalpat, S.; Gregory, R.; Wang, X.-D.; Jiang, J.; Raymond, M.; Rai, R.; Werho, D.; Roan, D.; White, B.E. Jr.; Tobin, P.J. [Freescale Semiconductor, Inc., Advanced Products Research and Development Laboratory, 3501 Ed Bluestein Boulevard, Austin, Texas 78721 (United States)

2005-09-01T23:59:59.000Z

248

Chemical analysis of HfO{sub 2}/Si (100) film systems exposed to NH{sub 3} thermal processing  

SciTech Connect

Nitrogen incorporation in HfO{sub 2}/SiO{sub 2} films utilized as high-k gate dielectric layers in advanced metal-oxide-semiconductor field effect transistors has been investigated. Thin HfO{sub 2} blanket films deposited by atomic layer deposition on either SiO{sub 2} or NH{sub 3} treated Si (100) substrates have been subjected to NH{sub 3} and N{sub 2} anneal processing. Several high resolution techniques including electron microscopy with electron energy loss spectra, grazing incidence x-ray diffraction, and synchrotron x-ray photoelectron spectroscopy have been utilized to elucidate chemical composition and crystalline structure differences between samples annealed in NH{sub 3} and N{sub 2} ambients as a function of temperature. Depth profiling of core level binding energy spectra has been obtained by using variable kinetic energy x-ray photoelectron spectroscopy with tunable photon energy. An 'interface effect' characterized by a shift of the Si{sup 4+} feature to lower binding energy at the HfO{sub 2}/SiO{sub 2} interface has been detected in the Si 1s spectra; however, no corresponding chemical state change has been observed in the Hf 4f spectra acquired over a broad range of electron take-off angles and surface sensitivities. The Si 2p spectra indicate Si-N bond formation beneath the HfO{sub 2} layer in the samples exposed to NH{sub 3} anneal. The NH{sub 3} anneal ambient is shown to produce a metastable Hf-N bond component corresponding to temperature driven dissociation kinetics. These findings are consistent with elemental profiles across the HfO{sub 2}/Si(100) interface determined by electron energy loss spectroscopy measurements. X-ray diffraction measurements on similarly treated films identify the structural changes resulting from N incorporation into the HfO{sub 2} films.

Lysaght, Patrick S.; Barnett, Joel; Bersuker, Gennadi I.; Woicik, Joseph C.; Fischer, Daniel A.; Foran, Brendan; Tseng, Hsing-Huang; Jammy, Raj [Front End Process Division, SEMATECH, 2706 Montopolis Drive, Austin, Texas 78741-6499 (United States); National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Physical Characterization Laboratory, Advanced Technology Development Facility, 2706 Montopolis Drive, Austin, Texas 78741-6499 (United States); Front End Process Division, SEMATECH, 2706 Montopolis Drive, Austin, Texas 78741-6499 (United States)

2007-01-15T23:59:59.000Z

249

Electronic Structures of C28H4 and Hf@C28H4 and Their Ions. SCF Calculations  

Science Journals Connector (OSTI)

In our calculations, we use the ab initio restricted Hartree?Fock (SCF) and configuration interaction (CI) methods to study the electronic structure respectively excluding and including electron correlation and the spin?orbit interaction. ... Systems of Calculation. ... The molecular integrals were calculated once for C28H4 (or Hf@C28H4) and stored on disk for all the SCF calculations of the neutral molecule and ions of C28H4 (or Hf@C28H4). ...

Debbie Fu-Tai Tuan; Russell M. Pitzer

1996-04-11T23:59:59.000Z

250

RF heating systems evolution for the WEST project  

SciTech Connect

Tore Supra is dedicated to long pulse operation at high power, with a record in injected energy of 1 GJ (2.8 MW 380 s) and an achieved capability of 12 MW injected power delivered by 3 RF systems: Lower Hybrid Current Drive (LHCD), Ion Cyclotron Resonance Heating (ICRH) and Electron Cyclotron Resonance Heating (ECRH). The new WEST project (W [tungsten] Environment in Steady-state Tokamak) aims at fitting Tore Supra with an actively cooled tungsten coated wall and a bulk tungsten divertor. This new device will offer to ITER a test bed for validating the relevant technologies for actively cooled metallic components, with D-shaped H-mode plasmas. For WEST operation, different scenarii able to reproduce ITER relevant conditions in terms of steady state heat loads have been identified, ranging from a high RF power scenario (15 MW, 30 s) to a high fluence scenario (10 MW, 1000 s). This paper will focus on the evolution of the RF systems required for WEST. For the ICRH system, the main issues are its ELM resilience and its CW compatibility, three new actively cooled antennas are being designed, with the aim of reducing their sensitivity to the load variations induced by ELMs. The LH system has been recently upgraded with new klystrons and the PAM antenna, the possible reshaping of the antenna mouths is presently studied for matching with the magnetic field line in the WEST configuration. For the ECRH system, the device for the poloidal movement of the mirrors of the antenna is being changed for higher accuracy and speed.

Magne, R.; Achard, J.; Armitano, A.; Argouarch, A.; Berger-By, G.; Bernard, J. M.; Bouquey, F.; Charabot, N.; Colas, L.; Corbel, E.; Delpech, L.; Ekedahl, A.; Goniche, M.; Guilhem, D.; Hillairet, J.; Jacquot, J.; Joffrin, E.; Litaudon, X.; Lombard, G.; Mollard, P. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); and others

2014-02-12T23:59:59.000Z

251

E-Print Network 3.0 - aps linac rf Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

the gradient... - cient use of the linacs and the RF power, at the cost ... Source: Berg, J. Scott - Department of Physics, Brookhaven National Laboratory Collection: Physics 4...

252

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 ..............................................................................................................................................................19 3.1. DESY GUN 2..................................................................................................................................................19 3.2. DESY GUN 4

253

E-Print Network 3.0 - argon rf plasma Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

- Princeton Plasma Physics Laboratory Collection: Plasma Physics and Fusion 6 REVERSE-VORTEX PLASMA STABILIZATION: EXPERIMENTS AND NUMERICAL SIMULATION Summary: -Frequency (RF)...

254

RF-driven advanced modes of ITER operation  

SciTech Connect

The impact of the Radio Frequency heating and current drive systems on the ITER advanced scenarios is analyzed by means of the CRONOS suite of codes for integrated tokamak modelling. As a first step, the code is applied to analyze a high power advanced scenario discharge of JET in order to validate both the heating and current drive modules and the overall simulation procedure. Then, ITER advanced scenarios, based on Radio Frequency systems, are studied on the basis of previous results. These simulations show that both hybrid and steady-state scenarios could be possible within the ITER specifications, using RF heating and current drive only.

Garcia, J.; Artaud, J. F.; Basiuk, V.; Decker, J.; Giruzzi, G.; Hawkes, N.; Imbeaux, F.; Litaudon, X.; Mailloux, J.; Peysson, Y.; Schneider, M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Brix, M. [UKAEA/Euratom Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom)

2009-11-26T23:59:59.000Z

255

High-voltage R-F feedthrough bushing  

DOE Patents (OSTI)

Described is a multi-element, high voltage radio frequency bushing for transmitting rf energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

Grotz, G.F.

1982-09-03T23:59:59.000Z

256

Study of AC/RF properties of SRF ingot niobium  

SciTech Connect

In an attempt to correlate the performance of superconducting radiofrequency cavities made of niobium with the superconducting properties, we present the results of the magnetization and ac susceptibility of the niobium used in the superconducting radiofrequency cavity fabrication. The samples were subjected to buffer chemical polishing (BCP) surface and high temperature heat treatments, typically applied to the cavities fabrications. The analysis of the results show the different surface and bulk ac conductivity for the samples subjected to BCP and heat treatment. Furthermore, the RF surface impedance is measured on the sample using a TE011 microwave cavity for a comparison to the low frequency measurements.

Dhakal, Pashupati; Tsindlekht, Menachem I.; Genkin, Valery M.; Ciovati, Gianluigi; Myneni, Ganapati Rao

2013-09-01T23:59:59.000Z

257

Asymmetric Bimodal Accelerator Cavity for Raising rf Breakdown Thresholds  

SciTech Connect

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.

Kuzikov, S. V. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov Street, Nizhny Novgorod, 603950 (Russian Federation); Kazakov, S. Yu. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Jiang, Y. [Physics Department, Yale University, New Haven, Connecticut 06520-8120 (United States); Hirshfield, J. L. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Physics Department, Yale University, New Haven, Connecticut 06520-8120 (United States)

2010-05-28T23:59:59.000Z

258

THERMAL MODELING OF ION EXCHANGE COLUMNS WITH SPHERICAL RF RESIN  

SciTech Connect

Models have been developed to simulate the thermal performance of RF columns fully loaded with radioactive cesium. Temperature distributions and maximum temperatures across the column were calculated during Small Column Ion Exchange (SCIX) process upset conditions with a focus on implementation at Hanford. A two-dimensional computational modeling approach was taken to include conservative, bounding estimates for key parameters such that the results will provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on RF. The current full-scale design for the SCIX system includes a central cooling tube, and one objective of these calculations was to examine its elimination to simplify the design. Results confirmed that a column design without a central cooling tube is feasible for RF, allowing for the possibility of significant design simplifications if it can be assumed that the columns are always filled with liquid. With active cooling through the four outer tubes, the maximum column diameter expected to maintain the temperature below the assumed media and safety limits is 26 inches, which is comparable to the current design diameter. Additional analysis was conducted to predict the maximum column temperatures for the previously unevaluated accident scenario involving inadvertent drainage of liquid from a cesium-saturated column, with retention of the ion exchange media and cesium in the column. As expected, much higher maximum temperatures are observed in this case due to the poor heat transfer properties of air versus liquid. For this hypothetical accident scenario involving inadvertent and complete drainage of liquid from a cesium-saturated column, the modeling results indicate that the maximum temperature within a 28 inch diameter RF column with external cooling is expected to exceed 250 C within 2 days, while the maximum temperature of a 12 inch column is maintained below 100 C. In addition, the calculation results demonstrate that the cooling tube system external to an air-filled column is not highly effective at reducing the maximum temperature, but the baseline design using a central cooling tube inside the column provides sufficient cooling to maintain the maximum temperature near the assumed safety limit.

Lee, S.; King, W.

2009-12-30T23:59:59.000Z

259

Beam dynamics studies for transverse electromagnetic mode type rf deflectors  

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.

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

2012-02-01T23:59:59.000Z

260

Glass antenna for RF-ion source operation  

DOE Patents (OSTI)

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.

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

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Frequency and amplitude control for an experimental linac rf drive  

E-Print Network (OSTI)

, India Chair of Advisory Committee: Dr. S. P. Bhattacharyya, The Texas Accelerator Center (TAC) experimental linear accelerator uses a radio- frequency quadrupole (RFQ) to accelerate a 10 mA beam of H ions to 500 keV. It is to be used as an injector... to form a high-energy input beam for large circular accelerators. The pulsed beam will require 100 kW peak rf power at 473 MHz. To satisfy the beam dynamics requirements for particle acceleration and to minimize beam spill, the frequency of the source...

Atre, Mahesh Purushottam

1992-01-01T23:59:59.000Z

262

Capacitively coupled RF voltage probe having optimized flux linkage  

DOE Patents (OSTI)

An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

1999-02-02T23:59:59.000Z

263

Electron-Transport Properties of Amorphous (Zr0.64ni0.36)1-Xalx Alloys  

E-Print Network (OSTI)

-4242 (Received 28 November 1988; revised manuscript received 16 March 1989) Measurements of the electrical resistivity p(T), thermopower S(T), and Hall coe%cient RH for a series of rapidly quenched Zr-Ni-Al alloys are reported for concentrations from x =0 to 0...-metal or ?metalloid amorphous alloys, the sign of RH can change from positive to negative as the concentration of the early transition metal is decreased. This is particular- ly well illustrated by measurements on amorphous Zr- based alloys, Zr-Cu, ' ' Zr-Ni, ' Zr...

BHATNAGAR, AK; PAN, R.; Naugle, Donald G.

1989-01-01T23:59:59.000Z

264

Etching characteristics of high-k dielectric HfO{sub 2} thin films in inductively coupled fluorocarbon plasmas  

SciTech Connect

Inductively coupled fluorocarbon (CF{sub 4}/Ar and C{sub 4}F{sub 8}/Ar) plasmas were used to etch HfO{sub 2}, which is a promising high-dielectric-constant material for the gate of complementary metal-oxide-semiconductor devices. The etch rates of HfO{sub 2} in CF{sub 4}/Ar plasmas exceeded those in C{sub 4}F{sub 8}/Ar plasmas. The tendency for etch rates to become higher in fluorine-rich (high F/C ratio) conditions indicates that HfO{sub 2} can be chemically etched by fluorine-containing species. In C{sub 4}F{sub 8}/Ar plasmas with a high Ar dilution ratio, the etch rate of HfO{sub 2} increased with increasing bias power. The etch rate of Si, however, decreased with bias power, suggesting that the deposition of carbon-containing species increased with increasing the power and inhibited the etching of Si. The HfO{sub 2}/Si selectivity monotonically increased with increasing power, then became more than 5 at the highest tested bias power. The carbon-containing species to inhibit etching of Si play an important role in enhancing the HfO{sub 2}/Si selectivity in C{sub 4}F{sub 8}/Ar plasmas.

Takahashi, Kazuo; Ono, Kouichi; Setsuhara, Yuichi [Department of Aeronautics and Astronautics, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

2005-11-15T23:59:59.000Z

265

Iron self-diffusion in amorphous FeZr?Fe57Zr multilayers measured by neutron reflectometry  

Science Journals Connector (OSTI)

Self-diffusion of iron in Fe67naturalZr33?Fe6757Zr33 multilayers has been investigated by neutron reflectometry. The as-deposited multilayer is amorphous in nature. It remains amorphous up to a temperature of 573K and thereafter nanocrystallizes with an average grain size of 6nm. The self-diffusion in the multilayers has been measured after isothermal vacuum annealing below the nanocrystallization temperature by monitoring the decay of the intensity of the first order Bragg peak, arising due to the isotopic periodicity. It has been found that the diffusivity at different temperatures follows an Arrhenius-type behavior with the preexponential factor D0=510?181m2s?1 and the activation energy E=0.380.05eV, respectively. These values of E and D0 follow the well-known ED0 correlation and on the basis of this correlation it is suggested that diffusion mechanism in the present case is not highly collective but involves a rather small group of atoms.

Mukul Gupta; Ajay Gupta; J. Stahn; M. Horisberger; T. Gutberlet; P. Allenspach

2004-11-18T23:59:59.000Z

266

Effects of N{sub 2}, O{sub 2}, and Ar plasma treatments on the removal of crystallized HfO{sub 2} film  

SciTech Connect

The effects of plasma treatment using Ar, N{sub 2}, and O{sub 2} on the removal of crystallized HfO{sub 2} films in a dilute HF solution were studied. The resulting damage in source and drain regions, and recess in isolation regions were also investigated. It was found that plasma nitridation with an ion energy of several hundred electron volts can lower the wet etch resistance of crystallized HfO{sub 2} films up to 70 A thick through the generation of Hf-N bonds. However, thermal nitridation did not introduce sufficient nitrogen into bulk crystallized HfO{sub 2} films to lower wet etch resistance. Plasma nitridation without bias power introduced nitrogen to the crystallized HfO{sub 2} in the region only within 10 A of the surface. The enhancement of the etch rate of crystallized HfO{sub 2} in dilute HF and the amount of recess in the active and isolation regions using N{sub 2}, O{sub 2}, and Ar plasma treatment have been evaluated. Results show that N{sub 2} plasma treatment is the most effective in enhancing the removal rate of crystallized HfO{sub 2} in dilute HF and minimizing recess on substrate among the plasmas studied.

Chen Jinghao; Yoo, Won Jong; Chan, Daniel S.H. [Silicon Nano Device Laboratory, Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)

2006-01-15T23:59:59.000Z

267

The structural and mechanical properties of a Cu??Zr??(at. %) alloy processed by High-Velocity-Injection (HVI)  

E-Print Network (OSTI)

) cooling rate, (3) defects and/or defect structure, (4) density and, (5) purity. The samples investigated in this research will be a copper- zirconium alloy of composition Cu Zr (at. ?) . This alloy was chosen because it is a member of a group...+Zr, C E6 8220C 4~0. 2 a~Zr, Cu 3200 2800 u 2600 ur 2400 g O 2200 ~ 2000 ~ i800 ~ l 600 i 100'C piZrCu3 965'C 935'C 895 C )I Sar I I g 47 92PC ~ 'C 1 400 Zr, cu $ ZrCu R O ZrCu~+Cu l200 lO 20 30 40 50 60 70 80 90 l00 WEIGHT...

Hays, Charles C.

2012-06-07T23:59:59.000Z

268

Index of /research/alcator/facility/Procedures/RF  

NLE Websites -- All DOE Office Websites (Extended Search)

RF RF [ICO] Name Last modified Size Description [DIR] Parent Directory - [ ] 0D8C3B68.pdf 08-May-2003 07:16 60K [ ] 0D8C3B68 Driver Kaptons.PDF 08-May-2003 07:16 69K [ ] 2002-10-28 - FMIT-3 Tuning to 78 MHZ.pdf 08-May-2003 07:16 425K [ ] FMIT 1 Crowb-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 1 Trans-cess.doc..pdf 08-May-2003 07:16 38K [ ] FMIT 1 Transformer Entry.pdf 08-May-2003 07:16 46K [ ] FMIT 2 Crowba-et access.pdf 08-May-2003 07:16 38K [ ] FMIT 2 Trans-cess.doc..pdf 08-May-2003 07:16 38K [ ] FMIT 2 Transformer Entry.pdf 08-May-2003 07:16 46K [ ] FMIT 3 Crowb-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 3 Trans-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 4 Crowb-et Access.pdf 08-May-2003 07:16 38K

269

Non-fusion applications of RF and microwave technology  

SciTech Connect

The processing of materials using rf and/or microwave power is a broad area that has grown significantly in the past few years. The authors have applied rf and microwave technology in the areas of ceramic sintering, plasma processing, and waste processing. The sintering of ceramics in the frequency range of 50 MHz-28 GHz has lead to unique material characteristics compared to materials that have been sintered conventionally. It has been demonstrated that sintering can be achieved in a variety of materials, including alumina, zirconia, silicon carbide, and boron carbide. In the area of plasma processing, progress has been made in the development and understanding of high density plasma sources, including inductively coupled plasma (ICP) sources. The effects of processing conditions on the ion energy distribution at the substrate surface (a critical processing issue) have been determined for a variety of process gases. The relationship between modeling and experiment is being established. Microwave technology has also been applied to the treatment of radioactive and chemical waste. The application of microwaves to the removal of contaminated concrete has been demonstrated. Details of these programs and other potential application areas are discussed.

Caughman, J.B.O.; Baity, F.W.; Bigelow, T.S.; Gardner, W.L.; Hoffman, D.J.; Forrester, S.C.; White, T.L.

1995-12-01T23:59:59.000Z

270

RF System Modeling for the CEBAF Energy Upgrade  

SciTech Connect

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 systems control algorithm: GDR (Generator Driven Resonator) and SEL (Self Excited Loop) [1] as well as klystron power requirements for different cavities and beam loads.

Tomasz Plawski, J. Hovater

2009-05-01T23:59:59.000Z

271

System studies of rf current drive for MST  

SciTech Connect

Two rf schemes are being studied on the MST reversed field pinch for their potential in current profile control experiments. MHD modeling has shown that a substantial externally-driven off axis parallel current can improve stability of the dominant core tearing modes. A radially localized axisymmetric population of fast electrons has been observed by SXR emission during LH injection (100kW at 800MHz), and is consistent with CQL3D modeling which predicts a small driven current. Computational work suggests that doubling the input power will statistically improve the LH-induced SXR signal to background ratio, and that about 2MW of injected power (an order of magnitude increase) will drive enough current for stabilization of tearing modes. Additionally, a 1 MW 5.5 GHz electron Bernstein wave (EBW) experiment is under construction, which utilizes a very simple and compact antenna compatible with the demands of the RFP. EBW allows access to electron cyclotron heating and current drive in the overdense plasma. Coupling of the external electromagnetic wave to the EBW has been demonstrated, and initial tests at {approx}100kW power have produced a small, localized xray flux consistent with rf heating and high diffusivity of fast electrons. Computational work is currently underway to answer the very important questions of how much power is required, and what level of electron diffusivity is tolerable, to generate a consequential amount of EBW current.

Anderson, J. K.; Burke, D. R.; Forest, C. B.; Goetz, J. A.; Hendries, E. R.; Seltzman, A. H.; Thomas, M. A. [Department of Physics, University of Wisconsin, Madison, WI (United States); Diem, S. [Oak Ridge National Laboratory, Oak Ridge TN (United States); Harvey, R. W. [CompX, Del Mar, CA (United States); Kaufman, M. C. [Department of Physics, University of Wisconsin, Madison, WI (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States)

2011-12-23T23:59:59.000Z

272

Library for RF Interactions in Orbit Following Codes  

SciTech Connect

A new code-library has been developed to handle quasi-linear wave particle interactions in orbit following Monte Carlo codes, RFOF (RF interactions in Orbit Following codes). This library will enable a large number of orbit following codes to model fast ion acceleration during ICRF and Lower Hybrid heating. The RFOF consists of two main modules: one evaluates the resonance condition, the other the resulting RF acceleration. The resonance condition is tested at each step along the orbit and the location of the next upcoming resonance is predicted. When a particle reaches the resonance, a quasi-linear acceleration is calculated with a novel Monte Carlo technique that avoids the time-consuming evaluation of phase-space derivatives of the interaction strength. In RFOF the wave-particles interactions are assumed to be localized to a single point on the orbit. This is often valid for the ion cyclotron and lower hybrid frequency ranges, but prevents the treatment of bounce and precessional resonances. The RFOF has been developed within the European Task Force for Integrated Tokamak Modelling, enabling interaction between experts in different fields. As a result the code is designed with a simple and generic interface, with a minimum of assumptions on e.g. the geometry. Successful integration with the two orbit following codes, ASCOT and SPOT, has already been demonstrated.

Johnson, T.; Hellsten, T.; Hoeoek, L. J. [Association EURATOM-VR, rary for RF Interactions in Orbit Following CoKTH (Sweden); Salmi, A. [Association Euratom - TEKES, Aalto University (Finland); Steinbrecher, G. [Association EURATOM-MEdC, Univ. of Craiova (Romania); Eriksson, L.-G. [European Commission, Research Directorate General (Belgium); Schneider, M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

2011-12-23T23:59:59.000Z

273

Designations of ds2p energy levels in neutral zirconium, hafnium, and rutherfordium (Z=104)  

Science Journals Connector (OSTI)

We have examined available data for the odd-parity energy-level structures in Zr and Hf, stimulated by the designations of four predicted 6d7s27p levels in the homologous atom rutherfordium (Rf, Z=104) by Eliav et al. [Phys. Rev. Lett. 74, 1079 (1995)]. We point out some errors and deficiencies in the Zr data and give the results of Hartree-Fock calculations for Hf 5d6s26p and Rf 6d7s27p levels. Configuration interactions within the (d+s)3p complexes were included. The resulting eigenvectors allow meaningful LS-coupling designations for most of the levels belonging mainly to Hf 5d6s26p and for most of the predicted Rf levels belonging mainly to 6d7s27p. Some changes in the designations assigned to these levels in the literature are suggested: in particular, the lowest level of both Hf 5d6s26p and Rf 6d7s27p is most appropriately designated F2o3. We point out the need for systematic whole-row studies of the low odd-parity configurations in 4d- and 5d-shell spectra. 1996 The American Physical Society.

W. C. Martin and Jack Sugar

1996-03-01T23:59:59.000Z

274

Identification of a quasiparticle band in very neutron-rich Zr104  

Science Journals Connector (OSTI)

The high spin levels of a very neutron-rich Zr104 nucleus have been reinvestigated by measuring the prompt ? rays in the spontaneous fission of Cf252. The ground-state band has been confirmed. A new sideband has been identified with a band-head energy at 1928.7 keV. The projected shell model is employed to investigate the band structure of Zr104. The results of calculated levels are in good agreement with the experimental data, and suggest that the new band in Zr104 may be based on the neutron ?5/2-[532]??3/2+[411] configuration.

E. Y. Yeoh (???); S. J. Zhu (???); J. H. Hamilton; A. V. Ramayya; Y. X. Liu (???); Y. Sun (??); J. K. Hwang; S. H. Liu; J. G. Wang (???); Y. X. Luo; J. O. Rasmussen; I. Y. Lee; H. B. Ding (???); L. Gu (??); Q. Xu (??); Z. G. Xiao (???)

2010-08-10T23:59:59.000Z

275

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

SciTech Connect

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 1000C. 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 600C annealed Mg:ZrO{sub 2} for all Mg concentrations.

Balaji, V., E-mail: thangadurai.p@gmail.com; Senthilkumaran, S., E-mail: thangadurai.p@gmail.com; Thangadurai, P., E-mail: thangadurai.p@gmail.com [Center for Nano Science and Technology, Pondicherry University, Puducherry- 605014 (India)

2014-04-24T23:59:59.000Z

276

Microsoft PowerPoint - IPRC 2012-Zr behavior  

NLE Websites -- All DOE Office Websites (Extended Search)

Behavior Behavior of Zirconium Oxide and Zirconium Metal in a LiCl-Li 2 O-Based Electrolytic Reduction System S. D. Herrmann, L. A. Wurth, N. J. Gese August 27, 2012 2012 International Pyroprocessing Research Conference The Abbey Resort Fontana, Wisconsin Introduction  Background - An electrometallurgical treatment process has been operating since 1996 to treat 25 MTHM of sodium-bonded uranium metal blanket and uranium metal alloy driver fuel from Experimental Breeder Reactor - II (EBR-II) at Idaho National Laboratory's Fuel Conditioning Facility. - In the course of retrieving EBR-II spent driver fuel for treatment, a significant quantity of degraded U-10Zr spent fuels, i.e., breached fuel exposed to air, has accumulated since 1996. - As oxidized material, it would require head-end treatment prior to electrorefining. - Electrolytic reduction is a candidate head-end treatment

277

The analysis of Ytrium doped BaZrO3  

Office of Scientific and Technical Information (OSTI)

Project Title: Enhanced Power Stability for Proton Conducting Solid Oxides Fuel Cells Project Title: Enhanced Power Stability for Proton Conducting Solid Oxides Fuel Cells Report Title: Computational modeling, synthesis, and characterization of BaZr 1-x Y x O 3-δ solid state proton conductor. Type of Report: Semi-Annual Technical Progress Report Reporting Period Start Date: March 30, 2003 Reporting Period End Date: September 30, 2003 Principle Authors: Boris Merinov, Claudio O. Dorso, William A. Goddard III, Jian Wu, and Sossina Haile Date Report was Issued: October 30, 2003 DOE Award Number: DE-FC26-02NT41631 Name and Address of Submitting Organization: California Institute of Technology, mail code 139- 74, 1200 E. California Blvd., Pasadena, CA 91125 1 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States

278

Pygmy dipole resonance and dipole polarizability in 90 Zr  

Science Journals Connector (OSTI)

Electric dipole (E1) reduced transition probability B(E1) of 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 ?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.

C. Iwamoto; A. Tamii; H. Utsunomiya; H. Akimune; H. Nakada; T. Shima; T. Hashimoto; T. Yamagata; T. Kawabata; Y. Fujita; H. Matsubara; T. Suzuki; H. Fujita; Y. Shimbara; M. Nagashima; M. Sakuda; T. Mori; T. Izumi; A. Okamoto; T. Kondo; T.-W. Lui; B. Bilgier; H. C. Kozer; K. Hatanaka

2014-01-01T23:59:59.000Z

279

R&D Requirements, RF Gun Mode Studies, FEL-2 Steady-State Studies, Preliminary FEL-1 Time-Dependent Studies, and Preliminary Layout Option Investigation  

E-Print Network (OSTI)

R&D Requirements, RF Gun Mode Studies, FEL-2 Steady-Stateinitial studies of the RF gun mode-coupling and potentialas more novel rf photocathode gun configurations these may

2005-01-01T23:59:59.000Z

280

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

E-Print Network (OSTI)

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

Qiang, J.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Permanent-magnet helicon sources and arrays: a new type of rf plasma Francis F. Chena)  

E-Print Network (OSTI)

Permanent-magnet helicon sources and arrays: a new type of rf plasma Francis F. Chena) and Humberto mechanism of RF coupling. However, the requirement of a dc magnetic field has prevented their wide acceptance in industry. The use of permanent magnets greatly simplifies helicon sources, and arrays of small

Chen, Francis F.

282

Permanent-magnet helicon sources and arrays: A new type of rf plasmaa... Francis F. Chenb  

E-Print Network (OSTI)

Permanent-magnet helicon sources and arrays: A new type of rf plasmaa... Francis F. Chenb mechanism of rf coupling. However, the requirement of a dc magnetic field has prevented their wide acceptance in industry. The use of permanent magnets greatly simplifies helicon sources, and arrays of small

Chen, Francis F.

283

PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC  

E-Print Network (OSTI)

PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC S. Schreiber. For this, an rf-gun based photoinjec- tor was installed late 1998 and is in operation since then gun [4] to match the beam charcteristics as close as pos- sible to the TESLA proposal. It is able

284

Studies of TTF RF Photocathode Gun using acoustic sensors J. Nelson and M. Ross  

E-Print Network (OSTI)

1 Studies of TTF RF Photocathode Gun using acoustic sensors J. Nelson and M. Ross SLAC November 27 RF high voltage breakdown locations in the photocathode gun system. It is not known if the acoustic gun [4] to locate its breakdown events during operation with a pulse length of 300µs and a pulse

285

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC  

E-Print Network (OSTI)

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC S. Schreiber was produced by a sub-harmonic in- jector using a thermionic gun, a buncher cavity, and one standard Linear Collider, a laser driven rf gun has been de- veloped and been brought in operation late fall 1998

286

Improved wireless security for GMSK-based devices using RF fingerprinting  

Science Journals Connector (OSTI)

Gaussian minimum shift keying (GMSK) is employed in current global system for mobile (GSM) networks and remains a viable option for future wireless systems. Physical layer (PHY) security is demonstrated using RF fingerprints from ... Keywords: GMSK, GSM networks, Gaussian minimum shift keying, MDA, PHY security, RF fingerprinting, SEI, authentication, electronic security, multiple discriminant analysis, physical layer, specific emitter identification, wireless networks, wireless security

Donald R. Reising; Michael A. Temple; Michael J. Mendenhall

2010-03-01T23:59:59.000Z

287

Laser-rf creation and diagnostics of seeded atmospheric pressure air and nitrogen plasmas  

E-Print Network (OSTI)

Laser-rf creation and diagnostics of seeded atmospheric pressure air and nitrogen plasmas Siqi Luo to the ambient air. The atmospheric-pressure plasma is then maintained with the 13.56 MHz rf power. Using of atmospheric-pressure air plasmas The kinetics of reactions and transitions in atmospheric- pressure air

Scharer, John E.

288

Tore Supra LH transmitter upgrade, a new RF driver for the power spectrum  

SciTech Connect

New real time tools have been developed for testing new 700kW/3.7GHz/CW klystrons and for the operations on very long plasma shots. After the commissioning of the 18 series tubes on the high power test bed facility, the installation of the first 8 klystrons in the Tore Supra transmitter and the adjustment tests on load, this upgrade work has been materialized during the last 2010 campaign by a successful operation on the Full Active Multijunction (FAM) C3 antenna, with new performances: 3.5MW/40s on plasma. The RF output power control in amplitude and phase has been improved for a better control of the wave spectrum launched into the plasma. The new klystrons have no modulating anode and the high cathode voltage must be adjusted with the RF input power in order to optimize the RF output power with a minimization of the thermal power losses in the collector. A new phase correction, depending on the 3 RF output power ranges used, has been introduced. The improvements made in 2009 and 2010 on the generic phase loop and the procedures used during the real time tests of the RF transfer functions in amplitude and phase are detailed below. All RF measurements systems, RF safety systems and the RF calibration procedures have been revised in order to have the best consistency, reproducibility and with a measurement error against the calorimetry measurement lower than 10%.

Berger-By, G.; Achard, J.; Armitano, A.; Bouquey, F.; Corbel, E.; Delpech, L.; Ekedahl, A.; Lombard, G.; Magne, R.; Mollard, P.; Pagano, M.; Prou, M.; Samaille, F.; Volpe, D.; Volpe, R. [CEA IRFM, F-13108 Saint-Paul-Lez-Durance (France)

2011-12-23T23:59:59.000Z

289

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

SciTech Connect

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.

Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M. [LPP/ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Wooldridge, E. [EURATOM/CCFE Fusion Association, Culham Science Centre (United Kingdom)

2011-12-23T23:59:59.000Z

290

High tunability barium strontium titanate thin films for rf circuit applications  

E-Print Network (OSTI)

High tunability barium strontium titanate thin films for rf circuit applications N. K. Pervez,a) P) Large variations in the permittivity of rf magnetron sputtered thin-film barium strontium titanate have/cm. © 2004 American Institute of Physics. [DOI: 10.1063/1.1818724] Barium strontium titanate (BST) is a solid

York, Robert A.

291

Radar Vibrometry: Investigating the Potential of RF microwaves to measure vibrations  

E-Print Network (OSTI)

Radar Vibrometry: Investigating the Potential of RF microwaves to measure vibrations K A Tsolis, C classification process. Recent research on vibrometry, the process of conducting vibration measurements. With this study we make a primary investigation of the capabilities of RF radar systems to measure vibrations. We

Haddadi, Hamed

292

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

E-Print Network (OSTI)

systems, RF powered systems present a new challenge for the energy management. A WSN node repeatedly in the capacitor. Therefore, we implemented an adaptive duty cycle control scheme that is optimized for RF energy but is not affected by weather and so it is more stable than solar and wind power. Almost all energy management

Tentzeris, Manos

293

Analytical Model for RF Power Performance of Deeply Scaled CMOS Devices  

E-Print Network (OSTI)

predictions from the model with measured load-pull data on 45 nm CMOS devices. II. MODEL DESCRIPTION The power by the load resistor. Fig. 1: Circuit diagram of a reduced conduction angle RF power amplifier. Fig. 2Analytical Model for RF Power Performance of Deeply Scaled CMOS Devices Usha Gogineni1 , Jesús del

del Alamo, Jesús A.

294

Study of high pressure gas filled RF cavities for muon collider  

E-Print Network (OSTI)

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.

Yonehara, Katsuya

2015-01-01T23:59:59.000Z

295

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

E-Print Network (OSTI)

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

Stancil, Daniel D.

296

A Time-AverageModel of the RF PlasmaSheath Demetre J, Economou.3  

E-Print Network (OSTI)

A Time-AverageModel of the RF PlasmaSheath Demetre J, Economou.3 Department of Chemical Engineering 97077 Richard C. Alkire* Department of Chemical Engineering, University of Illinois, Urbana, Illinois 6t801 ABSTRACT A time-average model of the RF plasma sheath was developed. The ion "fluid" equations

Economou, Demetre J.

297

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

DOE Patents (OSTI)

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.

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

1986-01-01T23:59:59.000Z

298

Studies on the Matching Network of the High Power Radio Frequency Transmitter for the NBI RF Ion Source  

Science Journals Connector (OSTI)

A radio frequency (RF) driven ion source has been developed at ASIPP (Institute of Plasma Physics, CAS) for the neutral beam injector with a 1MHz, 25kW RF power supply system. The paper describes the studies pe...

Renxue Su; Zhimin Liu; Yahong Xie; Yuqian Chen; Yuming Gu

2014-08-01T23:59:59.000Z

299

The external magnetic field dependence of RF splitting of57Fe hyperfine lines. NMR + Mssbauer double resonance experiment  

Science Journals Connector (OSTI)

We present the results of an experimental investigation of a RF splitting of57Fe hyperfine lines in the regime of NMR and Mssbauer ... have been performed as a function of RF field intensity and static magnetic

F. G. Vagizov

1995-01-01T23:59:59.000Z

300

HEAT TRANSFER ANALYSIS FOR FIXED CST AND RF COLUMNS  

SciTech Connect

In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, transient and steady state two-dimensional heat transfer models have been constructed for columns loaded with cesium-saturated crystalline silicotitanate (CST) or spherical Resorcinol-Formaldehyde (RF) beads and 6 molar sodium tank waste supernate. Radiolytic decay of sorbed cesium results in heat generation within the columns. The models consider conductive heat transfer only with no convective cooling and no process flow within the columns (assumed column geometry: 27.375 in ID with a 6.625 in OD center-line cooling pipe). Heat transfer at the column walls was assumed to occur by natural convection cooling with 35 C air. A number of modeling calculations were performed using this computational heat transfer approach. Minimal additional calculations were also conducted to predict temperature increases expected for salt solution processed through columns of various heights at the slowest expected operational flow rate of 5 gpm. Results for the bounding model with no process flow and no active cooling indicate that the time required to reach the boiling point of {approx}130 C for a CST-salt solution mixture containing 257 Ci/liter of Cs-137 heat source (maximum expected loading for SCIX applications) at 35 C initial temperature is about 6 days. Modeling results for a column actively cooled with external wall jackets and the internal coolant pipe (inlet coolant water temperature: 25 C) indicate that the CST column can be maintained non-boiling under these conditions indefinitely. The results also show that the maximum temperature of an RF-salt solution column containing 133 Ci/liter of Cs-137 (maximum expected loading) will never reach boiling under any conditions (maximum predicted temperature without cooling: 88 C). The results indicate that a 6-in cooling pipe at the center of the column provides the most effective cooling mechanism for reducing the maximum temperature with either ion exchange material. Sensitivity calculations for the RF resin porosity, the ambient external column temperature, and the cooling system configuration were performed under the baseline conditions to assess the impact of these parameters on the maximum temperatures. It is noted that the cooling mechanism at the column boundary (forced versus natural convection) and the cooling system configuration significantly impact the maximum temperatures. The analysis results provide quantitative information associated with process temperature control requirements and management of the SCIX column.

Lee, S

2007-10-17T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
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301

Model for Simulation of Hydride Precipitation in Zr-Based Used Fuel  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

for Simulation of Hydride Precipitation in Zr-Based Used Fuel for Simulation of Hydride Precipitation in Zr-Based Used Fuel Claddings: A Status Report on Current Model Capabilities Model for Simulation of Hydride Precipitation in Zr-Based Used Fuel Claddings: A Status Report on Current Model Capabilities The report demonstrates 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 claddings (regarded as a barrier for containment of radioactive fission products and fuel) are manufactured free of any hydrogen, they absorb hydrogen during service in the reactor. The amount of hydrogen that the cladding picks up is primarily a function of the exact chemistry and microstructure of the claddings and reactor operating conditions, time-temperature history, and

302

Phase studies of the Zr-H system at high hydrogen concentrations  

Science Journals Connector (OSTI)

The phase boundaries of the Zr-H system have been defined at high hydrogen concentrations, on the basis of studies performed on zirconium hydrides containing 4 at % uranium. The methods used include hightemperature X-ray diffraction, electrical resistance, dilatometry, and, to a limited extent, hot stage microscopy. The (?+?) two-phase region was found to exist between ZrH1.64 and ZrHi1.74 at 24 C. This region diminishes in width with increasing temperature and closes at 455 C and ZrH1.70. From this point, a single boundary, sloping toward higher hydrogen concentrations, separates the ? and ? single-phase regions. Precise lattice parameter measurements indicate that first-order transitions occur at the boundaries of the two-phase region. Theoretical considerations suggest that the ? ? ? transition is second order.

K.E. Moore; W.A. Young

1968-01-01T23:59:59.000Z

303

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

SciTech Connect

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.

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)

2013-07-15T23:59:59.000Z

304

Morphology and mechanism study for the synthesis of ZrB{sub 2}SiC powders by different methods  

SciTech Connect

ZrB{sub 2}SiC ceramics, whose SiC is generally incorporated into the system by mechanical mixing, are known to have better performance than monolithic ZrB{sub 2}. Therefore, synthesis of duplex ZrB{sub 2}SiC powders is beneficial for improving sinterability and mechanical properties of ZrB{sub 2}SiC composites. In the present work, ZrB{sub 2}SiC duplex powders with different morphologies were synthesized at 1550 C for 2 h using as-synthesized amorphous hydrous ZrO{sub 2}SiO{sub 2}. Both precipitation and solgel methods were used to prepare ZrO{sub 2}SiO{sub 2} precursors. ZrB{sub 2}SiC powder derived from precipitation method presented a rod-like morphology with smaller irregular particles adhering to them. And the morphology from solgel method was equiaxed shape with a very uniform distribution for principal components of Zr and Si. - Graphical abstract: SEM images of the ZrB2-SiC powders obtained by different methods. Display Omitted - Highlights: ZrB{sub 2}SiC powders with different morphologies were synthesized. Precipitation and solgel methods were used to prepare ZrO{sub 2}SiO{sub 2} precursors. Possible mechanisms of morphology formation were investigated. This work provided a potential way of morphology control for raw powders. The synthesized duplex powders achieved a uniform distribution of SiC in ZrB{sub 2}.

Zhao, Bin; Zhang, Yun [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Li, Junping [Aerospace Research Institute of Materials and Processing Technology, No. 1 Nan Da Hong Men Road, Fengtai District, Beijing 100076 (China); Yang, Biyun; Wang, Tingyu; Hu, Yongzhen; Sun, Dongfeng [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Li, Ruixing, E-mail: ruixingli@yahoo.com [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Yin, Shu [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Feng, Zhihai [Aerospace Research Institute of Materials and Processing Technology, No. 1 Nan Da Hong Men Road, Fengtai District, Beijing 100076 (China); Sato, Tsugio [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

2013-11-15T23:59:59.000Z

305

Process and properties of electroless Ni-Cu-P-ZrO{sub 2} nanocomposite coatings  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer The Ni-P and Ni-P-Cu-ZrO{sub 2} coatings were produced by electroless technique. Black-Right-Pointing-Pointer The influence of copper and ZrO{sub 2} nanoparticles on Ni-P was studied. Black-Right-Pointing-Pointer Surface morphology, structure and electrochemical behavior were evaluated. Black-Right-Pointing-Pointer The Ni-Cu-P-ZrO{sub 2} and Ni-P-ZrO{sub 2} coatings are more resistant to corrosion than Ni-P. Black-Right-Pointing-Pointer Introduction of Cu and ZrO{sub 2} in the matrix aids to the enhancement of microhardness. -- Abstract: Electroless Ni-Cu-P-ZrO{sub 2} composite coating was successfully obtained on low carbon steel matrix by electroless plating technique. Coatings with different compositions were obtained by varying copper as ternary metal and nano sized zirconium oxide particles so as to obtain elevated corrosion resistant Ni-P coating. Microstructure, crystal structure and composition of deposits were analyzed by SEM, EDX and XRD techniques. The corrosion behavior of the deposits was studied by anodic polarization, Tafel plots and electrochemical impedance spectroscopy (EIS) in 3.5% sodium chloride solution. The ZrO{sub 2} incorporated Ni-P coating showed higher corrosion resistance than plain Ni-P. The introduction of copper metal into Ni-P-ZrO{sub 2} enhanced the protection ability against corrosion. The influence of copper metal and nanoparticles on microhardness of coatings was evaluated.

Ranganatha, S. [Department of Studies in Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577451, Shimoga, Karnataka (India)] [Department of Studies in Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577451, Shimoga, Karnataka (India); Venkatesha, T.V., E-mail: drtvvenkatesha@yahoo.co.uk [Department of Studies in Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577451, Shimoga, Karnataka (India); Vathsala, K. [Nanotribology Laboratory, Mechanical engineering department, Indian Institute of Science, Bangalore (India)] [Nanotribology Laboratory, Mechanical engineering department, Indian Institute of Science, Bangalore (India)

2012-03-15T23:59:59.000Z

306

Oxygen impurity and microalloying effect in a Zr-based bulk metallic glass alloy  

E-Print Network (OSTI)

Oxygen impurity and microalloying effect in a Zr-based bulk metallic glass alloy C.T. Liu*, M composition Zr­10 at.%Al­5% Ti­17.9% Cu­14.6% Ni (BAM-11) was used to study the effects of oxygen impurities and microalloying on the microstructure and mechanical properties. Oxygen impurity at a level of 3000 appm

Pennycook, Steve

307

Mechanisms and selectivity for etching of HfO{sub 2} and Si in BCl{sub 3} plasmas  

SciTech Connect

The authors have investigated plasma etching of HfO{sub 2}, a high dielectric constant material, and poly-Si in BCl{sub 3} plasmas. Etching rates were measured as a function of substrate temperature (T{sub s}) at several source powers. Activation energies range from 0.2 to 1.0 kcal/mol for HfO{sub 2} and from 0.8 to 1.8 kcal/mol for Si, with little or no dependence on source power (20-200 W). These low activation energies suggest that product removal is limited by chemical sputtering of the chemisorbed Hf or Si-containing layer, with a higher T{sub s} only modestly increasing the chemical sputtering rate. The slightly lower activation energy for HfO{sub 2} results in a small improvement in selectivity over Si at low temperature. The surface layers formed on HfO{sub 2} and Si after etching in BCl{sub 3} plasmas were also investigated by vacuum-transfer x-ray photoelectron spectroscopy. A thin boron-containing layer was observed on partially etched HfO{sub 2} and on poly-Si after etching through HfO{sub 2} films. For HfO{sub 2}, a single B(1s) feature at 194 eV was ascribed to a heavily oxidized species with bonding similar to B{sub 2}O{sub 3}. B(1s) features were observed for poly-Si surfaces at 187.6 eV (B bound to Si), 189.8 eV, and 193 eV (both ascribed to BO{sub x}Cl{sub y}). In the presence of a deliberately added 0.5% air, the B-containing layer on HfO{sub 2} is largely unaffected, while that on Si converts to a thick layer with a single B(1s) peak at 194 eV and an approximate stoichiometry of B{sub 3}O{sub 4}Cl.

Wang Chunyu; Donnelly, Vincent M. [Department of Chemical and Biomolecular Engineering, University of Houston, 4800 Calhoun Road, Houston, Texas 77204 (United States)

2008-07-15T23:59:59.000Z

308

Polyatomic-buffered pulsed DF/HF laser using electron-beam or photolysis initiation  

SciTech Connect

The initial performance of pulsed DF/HF chain lasers is presented in which the effect of polyatomic diluents on laser behavior is systematically explored. Laser energy, pulse length, and spectral output were investigated as functions of diluent gas (NF3, SF6, CF4), total mixture pressure, the partial pressure of fuel and oxidizer, O/sub 2/ concentration, and strength of initiation. Magnetically-confined electron beam and photolytically initiated systems are found to yield comparable performance. Results include 65 J/liter-atm DF output at 200 Torr cavity pressure and the ability to suppress long wavelength transitions from the free-running spectrum. 21 references.

Amimoto, S.T.; Gross, R.W.F.; Harper, G.N.; Azevedo, L.S.; Hofland, R. Jr.

1987-06-01T23:59:59.000Z

309

High-K barrier penetration in Hf174: A challenge to K selection  

Science Journals Connector (OSTI)

A sensitive study of the decay of the deformation-aligned K=14, 4-?s isomer in Hf174 has revealed a multitude of the K-forbidden branches to the ground-state rotational band and other low-K bands, in competition with the known decays to high-K bands. The isomeric transitions have consistently low hindrance factors. These anomalous findings in an axially symmetric deformed nucleus severely test our understanding of the K-selection rule. The isomeric decay to an I=12 rotation-aligned state, and its mixing with the I=12 yrast state, provide a partial explanation.

P. M. Walker; G. Sletten; N. L. Gjrup; M. A. Bentley; J. Borggreen; B. Fabricius; A. Holm; D. Howe; J. Pedersen; J. W. Roberts; J. F. Sharpey-Schafer

1990-07-23T23:59:59.000Z

310

Cerenkov Radiator Driven by a Superconducting RF Electron Gun  

SciTech Connect

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.

Poole, B R; Harris, J R

2011-03-07T23:59:59.000Z

311

A new microphonics measurement method for superconducting RF cavities  

SciTech Connect

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.

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

2014-09-01T23:59:59.000Z

312

RF Heating in Electron Cyclotron Resonance Ion Sources  

SciTech Connect

ECRIS-Electron Cyclotron Resonance Ion Sources are able to feed accelerators with intense currents of highly charged ions. In ECRIS a high density-high temperature plasma is generated by means of the Electron Cyclotron Resonance Heating inside a B-min, MHD stable trap. The state of the art about the principal heating mechanisms will be given. The paper will specially discuss the most critical and still open issues concerning the influence of the magnetic field and of the RF frequency on the plasma heating, as well as the impact of possible non-linear pumping wave-to-plasma interactions. The contribution of INFN-LNS will be specifically underlined. A short review on the future perspectives for the design of new generation ion sources will be given in conclusion.

Mascali, D. [INFN - LNS, via S. Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria, 6 - 95125 Catania (Italy); Gammino, S.; Celona, L.; Ciavola, G. [INFN - LNS, via S. Sofia 62, 95123 Catania (Italy)

2011-12-23T23:59:59.000Z

313

RF and structural characterization of new SRF films  

SciTech Connect

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.

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

2009-09-01T23:59:59.000Z

314

RF Design Optimization for New Injector Cryounit at CEBAF  

SciTech Connect

A new injector superconducting RF (SRF) cryounit with one new 2-cell, B=0.6 cavity plus one refurbished 7-cell, B=0.97, C100 style cavity has been re-designed and optimized for the engineering compatibility of existing module for CEBAF operation. The optimization of 2-cell cavity shape for longitudinal beam dynamic of acceleration from 200keV to 533keV and the minimization of transverse kick due to the waveguide couplers to less than 1 mrad have been considered. Operating at 1497MHz, two cavities has been designed into a same footprint of CEBAF original quarter cryomodule to deliver an injection beam energy of 5MeV in less than 0.27{degree} rms bunch length and a maximum energy spread of 5keV.

Wang, Haipeng; Cheng, Guangfeng; Hannon, Fay E.; Hofler, Alicia S.; Kazimi, Reza; Preble, Joe; Rimmer, Robert A.

2013-06-01T23:59:59.000Z

315

National RF Test Facility as a multipurpose development tool  

SciTech Connect

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.

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.

1983-01-01T23:59:59.000Z

316

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

SciTech Connect

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.

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

2005-06-01T23:59:59.000Z

317

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

SciTech Connect

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.

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

2005-06-01T23:59:59.000Z

318

Structurefunction of the Na/H Exchanger Regulatory Factor (NHE-RF) 2199 The Journal of Clinical Investigation  

E-Print Network (OSTI)

, Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710 representing full-length NHE-RF as well as truncated and mutant forms of NHE-RF were deter- mined using/H exchanger activity that is not regulated by PKA. NHE-RF in the presence of ATP and Mg but not PKA, in

Hall, Randy A

319

Effect of Hf substitutions on the formation and superconductivity of Tl-1212 type phase TlSr{sub 2}(Ca{sub 1?x}Hf{sub x})Cu{sub 2}O{sub 7??}  

SciTech Connect

The TlSr{sub 2}(Ca{sub 1?x}Hf{sub x})Cu{sub 2}O{sub 7??} (Tl-1212) superconductor for x = 0.0 to 0.4 has been prepared by the solid state reaction method and studied by powder X-ray diffraction method, electrical resistance and scanning electron microscope (SEM). Most of the samples showed the Tl-1212 as the major phase and Tl-1201 as the minor phases. Small amounts of Hf-substitution (x ? 0.15 or x ? 0.25) maintained the formation of the Tl-1212 phase but larger amounts led to the formation of 1201 and an unknown impurity phase. The resistance versus temperature curve showed metallic behavior for all samples. The resistance versus temperature curves showed onset transition temperature (T{sub c} {sub onset}) between 38 and 47 K for Hf substitution.

Al-Sharabi, Annas; Abd-Shukor, R. [School of Applied Physics, Universiti Kebangsaan Malaysia 43600 Bangi, Selangor (Malaysia)

2013-11-27T23:59:59.000Z

320

Comparison of femtosecond and nanosecond laser-induced damage in HfO{sub 2} single-layer film and HfO{sub 2}-SiO{sub 2} high reflector  

SciTech Connect

HfO{sub 2} single layers, 800 nm high-reflective (HR) coating, and 1064 nm HR coating were prepared by electron-beam evaporation. The laser-induced damage thresholds (LIDTs) and damage morphologies of these samples were investigated with single-pulse femtosecond and nanosecond lasers. It is found that the LIDT of the HfO{sub 2} single layer is higher than the HfO{sub 2}-SiO{sub 2} HR coating in the femtosecond regime, while the situation is opposite in the nanosecond regime. Different damage mechanisms are applied to study this phenomenon. Damage morphologies of all samples due to different laser irradiations are displayed.

Yuan Lei; Zhao Yuanan; Shang Guangqiang; Wang Chengren; He Hongbo; Shao Jianda; Fan Zhengxiu [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China) and Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China) and Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

2007-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Suppression of near-edge optical absorption band in sputter deposited HfO{sub 2}-Al{sub 2}O{sub 3} nanolaminates containing nonmonoclinic HfO{sub 2}  

SciTech Connect

Nanolaminates of polycrystalline (tetragonal+orthorhombic) HfO{sub 2} and amorphous Al{sub 2}O{sub 3} are sputter deposited on unheated fused SiO{sub 2}, air annealed at 573-1273 K, and analyzed by x-ray diffraction and spectrophometry. Significant O 2p{yields}Hf 5d interband absorption occurs in all films at energy E{>=}6.2 eV. For E<6.2 eV, films annealed below 1273 K retain a featureless optical absorption edge despite further crystallization. A band with a 5.65 eV onset concurrently develops with m-HfO{sub 2} crystallization after a 1273 K anneal, indicating this phase and not nanocrystallinity per se is responsible for increased absorption.

Hoppe, E. E.; Aita, C. R. [Advanced Coatings Experimental Laboratory, University of Wisconsin-Milwaukee, P.O. Box 784, Milwaukee, Wisconsin 53201 (United States)

2008-04-07T23:59:59.000Z

322

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

SciTech Connect

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.

Larsen, R

2009-10-17T23:59:59.000Z

323

Effective work function of Pt, Pd, and Re on atomic layer deposited HfO{sub 2}  

SciTech Connect

Platinum and Pd show a significant difference in work function on SiO{sub 2} and high-K materials (HfO{sub 2}). The effective metal work functions for Pd, Pt, and Re on atomic layer deposited HfO{sub 2}, which are different from the vacuum work function and important for device threshold voltage control, are measured by the C-V method. The difference is attributed to the dipoles at the metal/HfO{sub 2} interface, which is a result of charge transfer across the interface. Moreover, the extracted charge neutrality level and screening parameter are correlated with the phase development, film stoichiometry, and density of interface states at the metal/high-K interface.

Gu Diefeng; Dey, Sandwip K.; Majhi, Prashant [Department of Chemical and Materials Engineering, Arizona State University, Tempe, Arizona 85287-6006 (United States) and Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287-5706 (United States); Planar CMOS Scaling, SEMATECH, Austin, Texas 78741 (United States)

2006-08-21T23:59:59.000Z

324

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

SciTech Connect

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.

Chung, M.; et al.

2013-10-01T23:59:59.000Z

325

Effects of shock waves on the performance of a cw supersonic HF chemical laser  

SciTech Connect

The effects of oblique shock waves on the gain and the output power of a cw supersonic HF chemical laser are theoretically investigated. A one-dimensional model is used to solve the flow of a premixed H/sub 2/--SF/sub 6/--H/sub e/ or H/sub 2/--F/sub 2/--H/sub e/ mixture through the resonator, allowing the presence of oblique shock waves in the flow. It is shown that a shock wave significantly affects the laser performance due to the gas compression at the shock front and due to acceleration of the chemical and energy transfer processes. It was found that immediately behind the shock front the gain coefficients and the photon energy sharply increase and further downstream they fall off rapidly, thus the profiles of the gain and radiation flux become narrower along the flow direction. Integration of the radiation flux along the cavity coordinate reveals that in some cases the total available power is significantly higher than the available power obtained in the undisturbed flow. For HF lasers pumped by the chain reactions it was found that choking occurs over a wide range of flow parameters including very weak shock waves. This is due to the large amount of heat released by the exothermic reactions.

Stricker, J.; Waichman, K.

1984-09-01T23:59:59.000Z

326

Corrosion Behavior of Copper Thin Films in Organic HF-Containing Cleaning Solution for Semiconductor Applications  

SciTech Connect

The corrosion behavior of electrochemically deposited copper thin films in deaerated and non-deaerated commercial cleaning solutions containing HF was investigated. Potentiodynamic polarization experiments were carried out to determine active, active-passive, passive, and transpassive regions. Corrosion rates were calculated from Tafel slopes. The addition of hydrogen peroxide to the solution and its influence on corrosion was also investigated by employing inductively coupled plasma-mass spectroscopy (ICP-MS) and X-ray photoelectron spectroscopy (XPS). The ICP-MS and potentiodynamic methods yielded comparable Cu dissolution rates. Surface analysis using atomic force microscopy and scanning electron microscopy, performed before and after the cleaning solution treatment, did not reveal any indication of pitting corrosion. The presence of hydrogen peroxide in the cleaning solution led to more than an order of magnitude suppression of copper dissolution rate. We ascribe this phenomenon to the formation of interfacial CuO detected by XPS on the wafer surface that dissolves at a slower rate in dilute HF.

Nabil G. Mistkawi,a,b Makarem A. Hussein,b Malgorzata Ziomek-Moroz,c and

2009-11-13T23:59:59.000Z

327

Excited States of Hf174 from the Decay of Ta174  

Science Journals Connector (OSTI)

The Ta174 activity was produced via the Lu175(?,5n)Ta174 reaction with 66-MeV ? particles from the Crocker Nuclear Laboratory 76-in. isochronous cyclotron. After removal of the F18, the half-lives were deduced by direct measurements. The half-lives of approximately 200 transitions, ranging in energy from 60 to 3000 keV, were identified using Ge(Li) detectors. Over 95% of these lines were assigned to Hf175, Hf174, or Lu173. The half-life of Ta174 was measured to be 71.5 6.5 min. Ge(Li)-Nal coincidence work has been done. The conversion-electron spectrum was first measured using a 3-mm Si(Li) detector with a cooled field-effect transistor and then using the same type of detector plus a magnet.The energies and ? intensities of the 100 transitions attributed to the decay of Ta174 were measured. 32 conversion coefficients were determined. 16 levels with spins and parities are proposed on the basis of ? intensities, coincidence information, and conversion coefficients. 16 more levels are proposed on the basis of energy sums. Spins and parities for four of these levels are suggested. 60 transitions are placed in the decay scheme. A very strong ? feed to the 4+ level of the ground-state rotational band was observed. M1 enhancement in the ? vibrational bands and K-forbidden ? transitions are discussed.

M. T. Gillin and N. F. Peek

1971-10-01T23:59:59.000Z

328

Measurements of spatial and frequency coherence of an equatorial hf path during spread-F  

SciTech Connect

In August 1990, the authors set up an hf path on the equatorial path between Maloelap Atoll and Bikini Atoll. This path, which had a range of 702 km, reflected in the ionosphere approximately 100 km north of the Altair radar location on Kwajalein. Transmitters at Maloelap broadcasted four cw tones within bandwidth of either 4 kHz, 9 kHz, or 70 kHz to be used to determine frequency coherence and also a phase-coded pseudo random sequence with a bandwidth of 60 kHz (channel probe) to be used to determine time delay spread. A spatial array of antennas was deployed at Bikini to measure spatial and frequency coherence using the cw broadcasts. The system was run in the post-sunset time period over two weeks during which almost every night showed significant degradation due to spread F resulting in rapid fading, decreased spatial and frequency coherence, and increased time delay spread. Doppler spreads of greater than 20 Hz were not uncommon, and the spatial correlation distances and frequency coherence bandwidths became so small (50 meters and 1 kHz respectively) that the experiment had to be readjusted. Measurements taken by the Altair incoherent scatter radar and the CUPRI 50 MHz coherent scatter radar indicate that although the bistatic hf channel is affected by the large scale plume structures, most of the [open quotes]damage[close quotes] is done by the bottomside spread F.

Fitzgerald, T.J.; Argo, P.E.; Carlos, R.C.

1993-01-01T23:59:59.000Z

329

Measurements of spatial and frequency coherence of an equatorial hf path during spread-F  

SciTech Connect

In August 1990, the authors set up an hf path on the equatorial path between Maloelap Atoll and Bikini Atoll. This path, which had a range of 702 km, reflected in the ionosphere approximately 100 km north of the Altair radar location on Kwajalein. Transmitters at Maloelap broadcasted four cw tones within bandwidth of either 4 kHz, 9 kHz, or 70 kHz to be used to determine frequency coherence and also a phase-coded pseudo random sequence with a bandwidth of 60 kHz (channel probe) to be used to determine time delay spread. A spatial array of antennas was deployed at Bikini to measure spatial and frequency coherence using the cw broadcasts. The system was run in the post-sunset time period over two weeks during which almost every night showed significant degradation due to spread F resulting in rapid fading, decreased spatial and frequency coherence, and increased time delay spread. Doppler spreads of greater than 20 Hz were not uncommon, and the spatial correlation distances and frequency coherence bandwidths became so small (50 meters and 1 kHz respectively) that the experiment had to be readjusted. Measurements taken by the Altair incoherent scatter radar and the CUPRI 50 MHz coherent scatter radar indicate that although the bistatic hf channel is affected by the large scale plume structures, most of the {open_quotes}damage{close_quotes} is done by the bottomside spread F.

Fitzgerald, T.J.; Argo, P.E.; Carlos, R.C.

1993-07-01T23:59:59.000Z

330

Superlattice Structure and Precipitates in O+ and Zr+ Ion Coimplanted SrTiO3: a Model Waste Form for 90Sr  

SciTech Connect

We investigate strontium titanate as a model waste form for 90Sr. Implantation with O+ and Zr+ ions, followed by annealing at 1423 K, was performed to simulate 90Sr to 90Zr decays. At low Zr concentrations, we observe formation of a ZrO-Sr superlattice structure. Ab initio calculations indicate that this atomic configuration is energetically favorable. At higher Zr concentrations, we observe precipitates of ZrO2 with a coherently strained interface, or a monolayer of disordered interfacial structure. Potential candidacy of 90SrTiO3 as a waste form for permanent disposal of 90Sr is discussed.

Jiang, Weilin; Van Ginhoven, Renee M.; Kovarik, Libor; Jaffe, John E.; Arey, Bruce W.

2012-07-13T23:59:59.000Z

331

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

SciTech Connect

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.

Kashiwagi, Shigeru; Kato, Ryukou; Isoyama, Goro [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Hayano, Hitoshi; Urakawa, Junji [Accelerator Laboratory, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

2010-02-03T23:59:59.000Z

332

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

SciTech Connect

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.

Tighe, R.; /SLAC

2011-08-31T23:59:59.000Z

333

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

SciTech Connect

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.

Kwan, Joe; Ji, Qing

2014-05-20T23:59:59.000Z

334

Operation of a planar-electrode ion trap array with adjustable RF electrodes  

E-Print Network (OSTI)

One path to scaling-up trapped atomic ions for large-scale quantum computing and simulation is to create a two-dimensional array of ion traps in close proximity to each other. A method to control the interactions between nearest neighboring ions is demonstrated and characterized here, using an adjustable radio-frequency (RF) electrode between trapping sites. A printed circuit board planar-electrode ion trap is demonstrated, trapping laser-cooled $^{40}$Ca$^+$ ions. RF shuttling and secular-frequency adjustment are shown as a function of the power applied to the addressed RF electrode. The trapped ion's heating rate is measured via a fluorescence recooling method.

Muir Kumph; Philip Holz; Kirsten Langer; Michael Niedermayr; Michael Brownnutt; Rainer Blatt

2014-02-04T23:59:59.000Z

335

Energy parameters and stability of the discharge in a nonchain, self-sustained-discharge-pumped HF laser  

SciTech Connect

The generation and discharge are studied in a nonchain HF laser operating on mixtures of SF{sub 6} with hydrogen and hydrocarbons. The specific output energy of the laser is 8.8 J L{sup -1} (73 J L{sup -1} atm{sup -1}) and the total lasing efficiency is 5.5%. It is shown that the formation and maintaining of a volume discharge in self-sustained-discharge-pumped HF lasers with a large content of electronegative gases is caused by the accumulation of the volume discharge of negative ions in conducting regions. (letters)

Tarasenko, Viktor F; Orlovskii, Viktor M; Panchenko, Aleksei N [Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation)

2001-12-31T23:59:59.000Z

336

Effect of nickel loading on the activity of Ni/ZrO2 for methane steam reforming at low temperature  

Science Journals Connector (OSTI)

The effect of Ni loading on the catalytic activity of Ni/ZrO2 catalyst for methane steam reforming was investigated. The sample containing 15 wt...

Long Q. Nguyen; Leonila C. Abella

2008-04-01T23:59:59.000Z

337

Interplay between gadolinium dopants and oxygen vacancies in HfO{sub 2}: A density functional theory plus Hubbard U investigation  

SciTech Connect

The influence of gadolinium (Gd) doping on the oxygen vacancy (V{sub O}) in monoclinic HfO{sub 2} have been studied by the first-principles calculations within the spin-polarized generalized gradient approximation plus Hubbard U approach. It is found that the Gd dopant and V{sub O} show strong attractive interaction, resulting in a cooperative effect that the substitution of Gd for Hf (Gd{sub Hf}) would increase the probability of oxygen vacancies generation and vice versa. The Gd{sub Hf} is more energetically favorable to be next to the vacancy site of a three-coordinated oxygen (O3), forming a complex defect Gd{sub Hf} + V{sub O}. A single Gd{sub Hf} acts a hole donor and passivates the defect states of V{sub O}. Our results suggest that the decrease of the V{sub O}-related defect states observed in the photoluminescence spectra of Gd-HfO{sub 2} is because Gd doping passivates the defect states of V{sub O}, rather than caused by decrease of V{sub O} concentration. Our findings would clarify the debate about the influence of Gd doping on the oxygen vacancies in HfO{sub 2}.

Zhang, Wei [Department of Criminal Science and Technology, Nanjing Forest Police College, Nanjing 210023 (China); Hou, Z. F., E-mail: zhufeng.hou@gmail.com [Department of Electronic Science, Xiamen University, Xiamen 361005 (China)

2014-03-28T23:59:59.000Z

338

A comparison of EISCAT and HF Doppler observations of a ULF wave D. M. Wright, T. K. Yeoman, J. A. Davies  

E-Print Network (OSTI)

A comparison of EISCAT and HF Doppler observations of a ULF wave D. M. Wright, T. K. Yeoman, J. A, Wright et al. (1997) presented a detailed study of ULF wave signatures observed by a new sounder at high observed by HF Doppler Correspondence to: D. M. Wright Presented at the Eighth International EISCAT

Paris-Sud XI, Université de

339

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

SciTech Connect

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.

Rhodes, Michael J.; Bell, Alexis T.

2005-03-21T23:59:59.000Z

340

Portsmouth DUF6 Conversion Final EIS - Appendix E: Impacts Associated with HF and CaF2 Conversion Product Sale and Use  

NLE Websites -- All DOE Office Websites (Extended Search)

Portsmouth DUF Portsmouth DUF 6 Conversion Final EIS APPENDIX E: IMPACTS ASSOCIATED WITH HF AND CaF 2 CONVERSION PRODUCT SALE AND USE HF and CaF 2 Conversion Products E-2 Portsmouth DUF 6 Conversion Final EIS HF and CaF 2 Conversion Products E-3 Portsmouth DUF 6 Conversion Final EIS APPENDIX E: IMPACTS ASSOCIATED WITH HF AND CaF 2 CONVERSION PRODUCT SALE AND USE E.1 INTRODUCTION During the conversion of the depleted uranium hexafluoride (DUF 6 ) inventory to depleted uranium oxide, products having some potential for sale to commercial users would be produced. These products would include aqueous hydrogen fluoride (HF) and calcium fluoride (CaF 2 , commonly referred to as fluorspar). These products are routinely used as commercial materials, and an investigation into their potential reuse was done; results are included as part of

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Paducah DUF6 Conversion Final EIS - Appendix E: Impacts Associated with HF and CaF2 Conversion Product Sale and Use  

NLE Websites -- All DOE Office Websites (Extended Search)

Paducah DUF Paducah DUF 6 Conversion Final EIS APPENDIX E: IMPACTS ASSOCIATED WITH HF AND CaF 2 CONVERSION PRODUCT SALE AND USE HF and CaF 2 Conversion Products E-2 Paducah DUF 6 Conversion Final EIS HF and CaF 2 Conversion Products E-3 Paducah DUF 6 Conversion Final EIS APPENDIX E: IMPACTS ASSOCIATED WITH HF AND CaF 2 CONVERSION PRODUCT SALE AND USE E.1 INTRODUCTION During the conversion of the depleted uranium hexafluoride (DUF 6 ) inventory to depleted uranium oxide, products having some potential for sale to commercial users would be produced. These products would include aqueous hydrogen fluoride (HF) and calcium fluoride (CaF 2 , commonly referred to as fluorspar). These products are routinely used as commercial materials, and an investigation into their potential reuse was done; results are included as part of

342

BEAM-BASED ALIGNMENT OF TTF RF-GUN USING V-CODE* W. Beinhauer, R. Cee, W. Koch, M. Krassilnikov  

E-Print Network (OSTI)

BEAM-BASED ALIGNMENT OF TTF RF-GUN USING V-CODE* W. Beinhauer, R. Cee, W. Koch, M. Krassilnikov , A), located after the RF- gun cavity, showed non-zero readings. Moreover the readings depended on RF-power, RF-phase and primary and secondary solenoid currents. This effect could be ex- plained by misalignments of the gun

343

Superconducting laser photocathode RF gun at BNL | U.S. DOE Office of  

Office of Science (SC) Website

Superconducting laser photocathode RF Superconducting laser photocathode RF gun at BNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Superconducting laser photocathode RF gun at BNL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Superconducting laser photocathode RF gun Developed at: Brookhaven National Laboratory (BNL), New York and Advanced Energy Systems,

344

Deeply-scaled GaN high electron mobility transistors for RF applications  

E-Print Network (OSTI)

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 ...

Lee, Dong Seup

2014-01-01T23:59:59.000Z

345

RF phase modulation of optical signals and optical/electrical signal processing  

E-Print Network (OSTI)

Analog RF phase modulation of optical signals has been a topic of interest for many years, mainly focusing on Intensity Modulation Direct Detection (IMDD). The virtues of coherent detection combined with the advantages of ...

Andrikogiannopoulos, Nikolas I

2006-01-01T23:59:59.000Z

346

A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor  

SciTech Connect

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.

Xiao, Binping [Brookhaven National Laboratory, Upton, New York (United States); Reece, Charles E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2014-02-01T23:59:59.000Z

347

A CW normal-conductive RF gun for free electron laser and energy recovery linac applications  

E-Print Network (OSTI)

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

Baptiste, Kenneth

2009-01-01T23:59:59.000Z

348

Analysis of slice transverse emittance evolutioin in a photocathode RF gun  

E-Print Network (OSTI)

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

Huang, Zhirong

2009-01-01T23:59:59.000Z

349

Experimental evaluation of 350 MHz RF accelerator windows for the low energy demonstration accelerator  

SciTech Connect

Radio frequency (RF) windows are historically a point where failure occurs in input power couplers for accelerators. To obtain a reliable, high-power, 350 MHz RF window for the Low Energy Demonstration Accelerator (LEDA) project of the Accelerator Production of Tritium program, RF windows prototypes from different vendors were tested. Experiments were performed to evaluate the RF windows by the vendors to select a window for the LEDA project. The Communications and Power, Inc. (CPI) windows were conditioned to 445 kW in roughly 15 hours. At 445 kW a window failed, and the cause of the failure will be presented. The English Electronic Valve, Inc. (EEV) windows were conditioned to 944 kW in 26 hours and then tested at 944 kW for 4 hours with no indication of problems.

Cummings, K.; Rees, D.; Roybal, W. [and others

1997-09-01T23:59:59.000Z

350

E-Print Network 3.0 - active rf pulse Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

that the duty ratios of the pulse are kept large for small input. Then, an RF pulse train is generated by mixing... the modulated envelope with the phase modulated carrier. The...

351

Tunable Substrate Integrated Waveguide Filters Implemented with PIN Diodes and RF MEMS Switches  

E-Print Network (OSTI)

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...

Armendariz, Marcelino

2012-02-14T23:59:59.000Z

352

Characteristics of Hydrogen Negative Ion Source with FET based RF System  

SciTech Connect

Characteristics of radio frequency (RF) plasma production were investigated using a FET inverter power supply as a RF generator. High density hydrogen plasma was obtained using an external coil wound a cylindrical ceramic tube (driver region) with RF frequency of lower than 0.5 MHz. When an axial magnetic field around 10 mT was applied to the driver region, an electron density increased drastically and attained to over 10{sup 19} m{sup -3} in the driver region. Effect of the axial magnetic field in driver and expansion region was examined. Lower gas pressure operation below 0.5 Pa was possible with higher RF frequency. H{sup -} density in the expansion region was measured by using laser photo-detachment system. It decreased as the axial magnetic field applied, which was caused by the increase of energetic electron from the driver.

Ando, A.; Matsuno, T.; Funaoi, T.; Tanaka, N. [Graduate School of Engineering, Tohoku University, Aoba-yama, Sendai, 980-8579 (Japan); Tsumori, K.; Takeiri, Y. [National Institute for Fusion Science, Oroshi-cho, Toki, 509-5292 (Japan)

2011-09-26T23:59:59.000Z

353

RF sputtering for controlling dihydride and monohydride bond densities in amorphous silicon hydride  

DOE Patents (OSTI)

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.

Jeffery, F.R.; Shanks, H.R.

1980-08-26T23:59:59.000Z

354

PRODUCTION OF LARGE VOLUME CYLINDRICAL RF PLASMA USING CIRCULAR MAGNETIC LINE CUSP FIELD  

Science Journals Connector (OSTI)

A large volume cylindrical rf (radio frequency) plasma source using a circular magnetic line cusp field has been developed for various large scale plasma processings. In this type of plasma source, a capacitively coupled 13.56 \\{MHz\\} rf plasma is produced in a circular magnetic line cusp field. Two versions of the plasma source have been constructed and tasted. The first version has a pair of peripheral rf electrodes placed outside the ionization chamber and is suitable for preparing a large volume uniform plasma. This plasma source can attain uniformity within 107 cm?3 over a 30 cm diameter region. The other which is provided with parallel doughnut plate electrodes forming part of the chamber wall serves as a high current plasma source, where the electron density is proportional to the rf power and equal to 7 109 cm?3 for 500 W.

K. YAMAUCHI; M. SHIBAGAKI; A. KONO; K. TAKAHASHI; T. SHEBUYA; E. YABE; K. TAKAYAMA

1993-01-01T23:59:59.000Z

355

Characteristics of single and dual radio-frequency (RF) plasma sheaths  

Science Journals Connector (OSTI)

The characteristics of radio-frequency (RF) plasma sheaths have been topics of much scientific ... in the study of physical phenomena in dusty plasmas. The sheaths behave special properties under various ... as c...

Zhong-ling Dai; You-nian Wang

2006-06-01T23:59:59.000Z

356

The analysis of conductive solid samples by r.f. capacitively coupled plasma at atmospheric pressure  

Science Journals Connector (OSTI)

A radiofrequency capacitively coupled plasma (rf CCP) with tip-ring electrode geometry has been used for the analysis of Al, Co, Cr, Cu, Mn, Mo, Ni, and V in low and medium alloyed steel. The sample is used as...

Sorin D. Anghel; Tiberiu Frentiu

1996-06-01T23:59:59.000Z

357

E-Print Network 3.0 - average current rf Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

management estimates the channel upon a frame recep- tion. MIMO... MHz bandwidth. 6.2 Simulation Results We compare the average energy per bit of RF chain management... measure...

358

The splitting of hyperfine lines of57Fe nuclei in RF magnetic field  

Science Journals Connector (OSTI)

It is shown experimentally, that for Moessbauer nuclei affected by the radio-frequency (RF) magnetic field of sufficient intensity at frequencies corresponding to ... occurs. Depending on the frequency of alterna...

F. G. Vagizov

1990-08-01T23:59:59.000Z

359

RF Analysis of ITER Remote Steering Antenna for Electron-Cyclotron Plasma Heating  

Science Journals Connector (OSTI)

An application of remote RF beam steering concept, based on image multiplication phenomena in a corrugated square waveguide, to electron-cyclotron plasma heating and current drive for ITER has been ... breakdown,...

G.G. Denisov; S.V. Kuzikov; N. Kobayashi

2001-12-01T23:59:59.000Z

360

Ignition of rf-Excited Lasers with Solid State and Tube Generators  

Science Journals Connector (OSTI)

An rf-excited CO2 laser has been developed at the Technical University Vienna. The construction bases upon a fast axial gas flow system with the gas flow divided into eight discharge tubes. The equivalent distrib...

B. Walter; M. Bohrer; D. Schucker

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

E-Print Network 3.0 - atmospheric rf device Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

results for: atmospheric rf device Page: << < 1 2 3 4 5 > >> 1 Packaging of Ka-Band Patch Antenna and Optoelectronic Components for Dual-Mode Indoor Wireless Communication...

362

Ion energy cost in a combined inductive-capacitive rf discharge  

Science Journals Connector (OSTI)

Experimental measurements were made of the ion energy cost ? as a function of the parameters of a combined rf inductive-capacitive discharge at low pressures (p<10?2 Torr). It was established that ?...does not de...

S. V. Dudin; A. V. Zykov; K. I. Polozhii; V. I. Farenik

1998-11-01T23:59:59.000Z

363

Automatic Pole and Q-Value Extraction for RF Structures  

SciTech Connect

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.

C. Potratz, H.-W. Glock, U. van Rienen, F. Marhauser

2011-09-01T23:59:59.000Z

364

Wide-Range Bolometer with RF Readout TES  

E-Print Network (OSTI)

To improve both scalability and noise-filtering capability of a Transition-Edge Sensor (TES), a new concept of a thin-film detector is suggested, which is based on embedding a microbridge TES into a high-Q planar GHz range resonator weakly coupled to a 50 Ohm-readout transmission line. Such a TES element is designed as a hot-electron microbolometer coupled to a THz range antenna and as a load of the resonator at the same time. A weak THz signal coupled to the antenna heats the microbridge TES, thus reducing the quality factor of the resonator and leading to a power increment in the readout line. The power-to-power conversion gain, an essential figure of merit, is estimated to be above 10. To demonstrate the basic concept, we fabricated and tested a few submicron sized devices from Nb thin films for operation temperature about 5 K. The dc and rf characterization of the new device is made at a resonator frequency about 5.8 GHz. A low-noise HEMT amplifier is used in our TES experiments without the need for a SQU...

Shitov, S V; Kuzmin, A A; Merker, M; Arndt, M; Wuensch, S H; Ilin, K S; Erhan, E; Ustinov, A; Siegel, M

2014-01-01T23:59:59.000Z

365

Superconducting RF Linac Technology for ERL Light Sources  

SciTech Connect

Energy Recovering Linacs (ERLs) offer an attractive alternative as drivers for light sources as they combine the desirable characteristics of both storage rings (high efficiency) and linear accelerators (superior beam quality). Using superconducting RF technology allows ERLs to operate more efficiently because of the inherent characteristics of SRF linacs, namely that they are high gradient-low impedance structures and their ability to operate in the long pulse or CW regime. We present an overview of the physics challenges encountered in the design and operation of ERL based light sources with particular emphasis on those issues related to SRF technology. These challenges include maximizing a cavity???????¢????????????????s Qo to increase cryogenic efficiency, maintaining control of the cavity field in the presence of the highest feasible loaded Q and providing adequate damping of the higher-order modes (HOMs). If not sufficiently damped, dipole HOMs can drive the multipass beam breakup (BBU) instability which ERLs are particularly susceptible to. Another challenge involves efficiently extracting the potentially large amounts of HOM power that are generated when a bunch traverses the SRF cavities and which may extend over a high range of frequencies. We present experimental data from the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in operation, aimed at addressing some of these issues. We conclude with an outlook towards the future of ERL based light sources.

Chris Tennant

2005-08-01T23:59:59.000Z

366

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

SciTech Connect

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)

Uchida, T.; Hirooka, S.; Kato, M.; Morimoto, K. [Japan Atomic Energy Agency, 4-33, Muramatsu, Tokai-mura, Naka-gun, Ibaraki 319-1194 (Japan); Sugata, H.; Shibata, K.; Sato, D. [Inspection Development Company, 4-33, Muramatsu, Tokai-mura, Naka-gun, Ibaraki 319-1194 (Japan)

2013-07-01T23:59:59.000Z

367

Laser cooling and sympathetic cooling in a linear quadrupole rf trap  

E-Print Network (OSTI)

LASER COOLING AND SYMPATHETIC COOLING IN A LINEAR QUADRUPOLE RF TRAP A Dissertation by VLADIMIR LEONIDOVICH RYJKOV Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY December 2003 Major Subject: Physics LASER COOLING AND SYMPATHETIC COOLING IN A LINEAR QUADRUPOLE RF TRAP A Dissertation by VLADIMIR LEONIDOVICH RYJKOV Submitted to Texas A&M University in partial fulfillment of the requirements...

Ryjkov, Vladimir Leonidovich

2005-02-17T23:59:59.000Z

368

Comparison of the theory and the practice of rf current drive  

SciTech Connect

The theory of rf-driven plasma currents is applied to the lower-hybrid experiments on the PLT tokamak. Particular emphasis is placed on those experiments in which the plasma current was varying. The comparison between theory and experiment is made with respect to the efficiency with which rf energy was converted to poloidal magnetic field energy. Good agreement is found irrespective of whether the current was increasing, constant, or decreasing.

Karney, C.F.F.; Fisch, N.J.; Jobes, F.C.

1984-10-01T23:59:59.000Z

369

INVESTIGATION OF LASER SUPPORTED DETONATION WAVES AND THERMAL COUPLING USING 2.8um HF LASER IRRADIATED METAL TARGETS  

E-Print Network (OSTI)

INVESTIGATION OF LASER SUPPORTED DETONATION WAVES AND THERMAL COUPLING USING 2.8um HF LASER of Hull, Hull, HU6 7RX, England. Abstract.- The formation and propagation of laser supported detonation was obtained in a of laser supported detonation waves and thermal o. 300 nsec. pulse (FHHM). The laser output

Boyer, Edmond

370

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

SciTech Connect

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 2030 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.

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)

2014-05-19T23:59:59.000Z

371

Plastic deformation magnetic assembly of out-of-plane structures using vapour phase hydrofluoric (HF) acid release  

Science Journals Connector (OSTI)

We report on the fabrication of out-of-plane microstructures using plastic deformation magnetic assembly (PDMA) and vapour phase HF release process. A 0.5@mm thin silicon oxide (SiO"2) layer deposited on blank silicon has been implemented as a sacrificial ... Keywords: Dry release method, Hydrofluoric acid, Plastic deformation magnetic assembly

P. Argyrakis; R. Cheung

2009-11-01T23:59:59.000Z

372

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

E-Print Network (OSTI)

The 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 will be a powerful tool for solar physics and space weather investigations, through its ability to characterize

Ellingson, Steven W.

373

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

E-Print Network (OSTI)

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

Misra, Durgamadhab "Durga"

374

Mechanisms for plasma etching of HfO{sub 2} gate stacks with Si selectivity and photoresist trimming  

SciTech Connect

To minimize leakage currents resulting from the thinning of the insulator in the gate stack of field effect transistors, high-dielectric constant (high-k) metal oxides, and HfO{sub 2} in particular, are being implemented as a replacement for SiO{sub 2}. To speed the rate of processing, it is desirable to etch the gate stack (e.g., metal gate, antireflection layers, and dielectric) in a single process while having selectivity to the underlying Si. Plasma etching using Ar/BCl{sub 3}/Cl{sub 2} mixtures effectively etches HfO{sub 2} while having good selectivity to Si. In this article, results from integrated reactor and feature scale modeling of gate-stack etching in Ar/BCl{sub 3}/Cl{sub 2} plasmas, preceded by photoresist trimming in Ar/O{sub 2} plasmas, are discussed. It was found that BCl{sub n} species react with HfO{sub 2}, which under ion impact, form volatile etch products such as B{sub m}OCl{sub n} and HfCl{sub n}. Selectivity to Si is achieved by creating Si-B bonding as a precursor to the deposition of a BCl{sub n} polymer which slows the etch rate relative to HfO{sub 2}. The low ion energies required to achieve this selectivity then challenge one to obtain highly anisotropic profiles in the metal gate portion of the stack. Validation was performed with data from literature. The effect of bias voltage and key reactant probabilities on etch rate, selectivity, and profile are discussed.

Shoeb, Juline; Kushner, Mark J. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States)

2009-11-15T23:59:59.000Z

375

Identification of a quasiparticle band in very neutron-rich {sup 104}Zr  

SciTech Connect

The high spin levels of a very neutron-rich {sup 104}Zr nucleus have been reinvestigated by measuring the prompt {gamma} rays in the spontaneous fission of {sup 252}Cf. The ground-state band has been confirmed. A new sideband has been identified with a band-head energy at 1928.7 keV. The projected shell model is employed to investigate the band structure of {sup 104}Zr. The results of calculated levels are in good agreement with the experimental data, and suggest that the new band in {sup 104}Zr may be based on the neutron {nu}5/2{sup -}[532] x {nu}3/2{sup +}[411] configuration.

Yeoh, E. Y.; Wang, J. G.; Ding, H. B.; Gu, L.; Xu, Q.; Xiao, Z. G. [Department of Physics, Tsinghua University, Beijing 100084 (China); Zhu, S. J. [Department of Physics, Tsinghua University, Beijing 100084 (China); Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Liu, S. H. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Liu, Y. X. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); School of Science, Huzhou Teachers College, Huzhou 313000 (China); Sun, Y. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Luo, Y. X. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Rasmussen, J. O.; Lee, I. Y. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2010-08-15T23:59:59.000Z

376

Hall Effect, Resistivity, and Magnetoresistivity of Th, U, Zr, Ti, and Nb  

Science Journals Connector (OSTI)

The Hall effect, resistivity, and magnetoresistivity of Th, U, Zr, Ti, and Nb have been studied at temperatures between ?1K and room temperature and in magnetic fields up to 30 kilogauss. Strong temperature and purity dependences were observed in the Hall coefficients of U, Ti, and Zr. In addition, the Hall coefficient of Zr was strongly dependent upon magnetic field strength at liquid helium temperatures. Comparisons with theory have been carried out, and it is concluded that existing theories are not sufficiently general to account quantitatively for the observed temperature and magnetic field dependences of the Hall effect and resistivity. Unusual behavior was observed in the magnetic-field-induced superconducting transition of Nb.

Ted G. Berlincourt

1959-05-15T23:59:59.000Z

377

Photocatalytic studies of HoZrO nano-composite with controllable composition and defects  

SciTech Connect

With the help of solgel method assisted by melting salt, a series of HoZrO 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 HoZrO 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: HoZrO 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.

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)

2013-09-15T23:59:59.000Z

378

Epitaxial Pb(Zr, Ti)O3 thin films with coexisting tetragonal and rhombohedral phases  

Science Journals Connector (OSTI)

Epitaxial Pb(Zr, Ti)O3 thin films having coexisting tetragonal and rhombohedral phases have been successfully fabricated with the film compositions that correspond to the Zr-rich region of the morphotropic phase boundary (MPB). The key to the present success is to quantitatively understand the shift of the MPB under a film stress. The present fabrication has been theoretically justified by superimposing the computed temperature-dependent film stress on the theoretical temperature-stress (T-S) phase diagram and by delineating a probable phase-transition path upon cooling the film from the processing temperature.

S. Hoon Oh and Hyun M. Jang

2001-03-12T23:59:59.000Z

379

Silicon photodiode with selective Zr/Si coating for extreme ultraviolet spectral range  

SciTech Connect

The procedure of manufacturing silicon photodiodes with an integrated Zr/Si filter for extreme ultraviolet (EUV) spectral range is developed. A setup for measuring the sensitivity profile of detectors with spatial resolution better than 100 {mu}m is fabricated. The optical properties of silicon photodiodes in the EUV and visible spectral ranges are investigated. Some characteristics of SPD-100UV diodes with Zr/Si coating and without it, as well as of AXUV-100 diodes, are compared. In all types of detectors a narrow region beyond the operating aperture is found to be sensitive to the visible light. (photodetectors)

Aruev, P N; Barysheva, Mariya M; Ber, B Ya; Zabrodskaya, N V; Zabrodskii, V V; Lopatin, A Ya; Pestov, Alexey E; Petrenko, M V; Polkovnikov, V N; Salashchenko, Nikolai N; Sukhanov, V L; Chkhalo, Nikolai I

2012-10-31T23:59:59.000Z

380

Deformation Mechanisms in Tube Billets from Zr-1%Nb Alloy under Radial Forging  

SciTech Connect

Features of the deformation process by cold radial forging of tube billets from Zr-1%Nb alloy were reconstructed on the basis of X-ray data concerning their structure and texture. The cold radial forging intensifies grain fragmentation in the bulk of billet and increases significantly the latent hardening of potentially active slip systems, so that operation only of the single slip system becomes possible. As a result, in radially-forged billets unusual deformation and recrystallization textures arise. These textures differ from usual textures of {alpha}-Zr by the mutual inversion of crystallographic axes, aligned along the axis of tube.

Perlovich, Yuriy; Isaenkova, Margarita; Fesenko, Vladimir; Krymskaya, Olga [National Research Nuclear University 'Moscow Engineering Physics Institute', Kashirskoe shosse, 31, Moscow, 115409 (Russian Federation); Zavodchikov, Alexander [Perm Research Technological Institute, Hasan Heroes street, 41, Perm, 614990 (Russian Federation)

2011-05-04T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Direct observation of bias-dependence potential distribution in metal/HfO{sub 2} gate stack structures by hard x-ray photoelectron spectroscopy under device operation  

SciTech Connect

Although gate stack structures with high-k materials have been extensively investigated, there are some issues to be solved for the formation of high quality gate stack structures. In the present study, we employed hard x-ray photoelectron spectroscopy in operating devices. This method allows us to investigate bias dependent electronic states, while keeping device structures intact. Using this method, we have investigated electronic states and potential distribution in gate metal/HfO{sub 2} gate stack structures under device operation. Analysis of the core levels shifts as a function of the bias voltage indicated that a potential drop occurred at the Pt/HfO{sub 2} interface for a Pt/HfO{sub 2} gate structure, while a potential gradient was not observed at the Ru/HfO{sub 2} interface for a Ru/HfO{sub 2} gate structure. Angle resolved photoelectron spectroscopy revealed that a thicker SiO{sub 2} layer was formed at the Pt/HfO{sub 2} interface, indicating that the origin of potential drop at Pt/HfO{sub 2} interface is formation of the thick SiO{sub 2} layer at the interface. The formation of the thick SiO{sub 2} layer at the metal/high-k interface might concern the Fermi level pinning, which is observed in metal/high-k gate stack structures.

Yamashita, Y. [National Institute for Materials Science, Advanced Electric Materials Center, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); National Institute for Materials Science, NIMS Beamline Station at SPring-8, 1-1-1 Kto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yoshikawa, H.; Kobayashi, K. [National Institute for Materials Science, NIMS Beamline Station at SPring-8, 1-1-1 Kto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Chikyo, T. [National Institute for Materials Science, Advanced Electric Materials Center, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

2014-01-28T23:59:59.000Z

382

Thermodynamic properties and interfacial layer characteristics of HfO{sub 2} thin films deposited by plasma-enhanced atomic layer deposition  

SciTech Connect

The thermodynamic properties and interfacial characteristics of HfO{sub 2} thin films that were deposited by the direct plasma atomic layer deposition (DPALD) method are investigated. The as-deposited HfO{sub 2} films that were deposited by the DPALD method show crystallization of the HfO{sub 2} layers, which initiates at approximately the 35th cycle (about 2.8 nm) of the DPALD process. Medium-energy ion scattering analysis reveals that the direct O{sub 2} plasma causes a compositional change in the interfacial layer as the process progresses. With an increase in the number of process cycles, the Si content decreases and the O content increases at that position, so that the HfO{sub 2}-like Hf-silicate layer is formed on top of the interfacial layer. The enhanced physical reactivity of the oxygen ions in the direct plasma and the Hf-silicate layer may be the driving forces that accelerate the early crystallization of the HfO{sub 2} layer in the DPALD process in the as-deposited state.

Kim, Inhoe; Kuk, Seoungwoo; Kim, Seokhoon; Kim, Jinwoo; Jeon, Hyeongtag; Cho, M.-H.; Chung, K.-B. [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Korea Research Institute of Standard and Science, Daejeon 305-600 (Korea, Republic of)

2007-05-28T23:59:59.000Z

383

Am phases in the matrix of a U-Pu-Zr alloy with Np, Am, and rare-earth elements  

SciTech Connect

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.

Dawn E Janney; J. Rory Kennedy; James W. Madden; Thomas P. O'Holleran

2015-01-01T23:59:59.000Z

384

Epitaxial growth of lead zirconium titanate thin films on Ag buffered Si substrates using rf sputtering  

E-Print Network (OSTI)

substrates such as SrTiO3, MgO, and LaAlO3 using different deposition methods sputtering, pubed laser with good dif- fusion barrier properties and epitaxy with Si need to be used. In this work, we investigated grown epitaxially on HF-etched Si 001 with cube-on-cube orientation relationship, though the lattice

Laughlin, David E.

385

Comparison of Measured and Calculated Coupling between a Waveguide and an RF Cavity Using CST Microwave Studio  

SciTech Connect

Accurate predications of RF coupling between an RF cavity and ports attached to it have been an important study subject for years for RF coupler and higher order modes (HOM) damping design. We report recent progress and a method on the RF coupling simulations between waveguide ports and RF cavities using CST Microwave Studio in time domain (Transit Solver). Comparisons of the measured and calculated couplings are presented. The simulated couplings and frequencies agree within {approx} 10% and {approx} 0.1% with the measurements, respectively. We have simulated couplings with external Qs ranging from {approx} 100 to {approx} 100,000, and confirmed with measurements. The method should also work well for higher Qs, and can be easily applied in RF power coupler designs and HOM damping for normal-conducting and superconducting cavities.

J. Shi; H. Chen; S. Zheng; D. Li; R.A. Rimmer; H. Wang

2006-06-26T23:59:59.000Z

386

Application of new simulation algorithms for modeling rf diagnostics of electron clouds  

SciTech Connect

Traveling wave rf diagnostics of electron cloud build-up show promise as a non-destructive technique for measuring plasma density and the efficacy of mitigation techniques. However, it is very difficult to derive an absolute measure of plasma density from experimental measurements for a variety of technical reasons. Detailed numerical simulations are vital in order to understand experimental data, and have successfully modeled build-up. Such simulations are limited in their ability to reproduce experimental data due to the large separation of scales inherent to the problem. Namely, one must resolve both rf frequencies in the GHz range, as well as the plasma modulation frequency of tens of MHz, while running for very long simulations times, on the order of microseconds. The application of new numerical simulation techniques allow us to bridge the simulation scales in this problem and produce spectra that can be directly compared to experiments. The first method is to use a plasma dielectric model to measure plasma-induced phase shifts in the rf wave. The dielectric is modulated at a low frequency, simulating the effects of multiple bunch crossings. This allows simulations to be performed without kinetic particles representing the plasma, which both speeds up the simulations as well as reduces numerical noise from interpolation of particle charge and currents onto the computational grid. Secondly we utilize a port boundary condition model to simultaneously absorb rf at the simulation boundaries, and to launch the rf into the simulation. This method improves the accuracy of simulations by restricting rf frequencies better than adding an external (finite) current source to drive rf, and absorbing layers at the boundaries. We also explore the effects of non-uniform plasma densities on the simulated spectra.

Veitzer, Seth A.; Smithe, David N.; Stoltz, Peter H. [Tech-X Corporation, Boulder, CO, 80303 (United States)

2012-12-21T23:59:59.000Z

387

Total ionizing dose effect of ?-ray radiation on the switching characteristics and filament stability of HfOx resistive random access memory  

SciTech Connect

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.

Fang, Runchen; Yu, Shimeng, E-mail: shimengy@asu.edu [School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, Arizona 85281 (United States); School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Gonzalez Velo, Yago; Chen, Wenhao; Holbert, Keith E.; Kozicki, Michael N.; Barnaby, Hugh [School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States)

2014-05-05T23:59:59.000Z

388

Modeling of Zircon (ZrSiO{sub 4}) and Zirconia (ZrO{sub 2}) using ADF-GUI Software  

SciTech Connect

Natural zircon (ZrSiO{sub 4}) has very high concentration of Uranium and Thorium of up to 5000 ppm. Radioactive decay process of alpha particles from these impurities affects some changes like several atomic displacements in the crystalline structure of zircon. The amount of track density caused by alpha particles decay process of these radioactive materials in zircon can be decreased with annealing temperatures from 700 deg. C to 980 deg. C. Recently it has been extensively studied as the possible candidate material for immobilization of fission products and actinides. Besides, zirconia (ZrO{sub 2}), product from natural zircon, is widely used in industrial field because it has excellent chemical and mechanical properties at high temperature. Dielectric constant of monoclinic, cubic and tetragonal ZrO{sub 2} can be found in the range of 22, 35 and 50 by computer simulation works. In recent years, atomistic simulations and modeling have been studied, because a lot of computational techniques can offer atomic-level approaching with minimum errors in estimations. One favorite methods is Density Functional Theory (DFT). In this study, ADF-GUI software from DFT will be used to calculate the frequency and absorption Intensity of zircon and zirconia molecules. The data from calculations will be verified with experimental works such as Raman Spectroscopy, AFM and XRD.

Lwin, Maung Tin Moe [Applied Radiation Laboratory, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Amin, Yusoff Mohd; Kassim, Hasan Abu; Kamaluddin, Burhanuddin [Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2010-07-07T23:59:59.000Z

389

Effect of thermal annealing on charge exchange between oxygen interstitial defects within HfO{sub 2} and oxygen-deficient silicon centers within the SiO{sub 2}/Si interface  

SciTech Connect

We compare the charging response of rapid thermally annealed (800 and 1000 deg. C) 4 nm thick HfO{sub 2} to as-deposited HfO{sub 2} on Si by measuring the surface potential of the HfO{sub 2} layers after vacuum ultraviolet (VUV) irradiation with 11.6 eV photons. From VUV spectroscopy, we determined all HfO{sub 2} layers show the presence of oxygen-interstitial defects (OIDs). The electronic states of OID in HfO{sub 2} line up in energy with oxygen-deficient Si centers within the SiO{sub 2} interfacial layer. This implies charge exchange between OIDs within HfO{sub 2} and the O-deficient silicon centers within the SiO{sub 2} interfacial layer are very important for controlling the radiation-induced trapped charge in HfO{sub 2} dielectric stacks.

Lauer, J. L.; Shohet, J. L. [Department of Electrical and Computer Engineering and Plasma Processing and Technology Laboratory, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Nishi, Y. [Stanford University, Stanford, California 94305 (United States)

2009-04-20T23:59:59.000Z

390

Simulation of RF Cavity Dark Current In Presence of Helical Magnetic Field  

SciTech Connect

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.

Romanov, Gennady; Kashikhin, Vladimir; /Fermilab

2012-05-01T23:59:59.000Z

391

RF Heating and Current Drive in Magnetically Confined Plasma: a Historical Perspective  

SciTech Connect

The history of high power RF waves injected into magnetically confined plasma for the purposes of heating to fusion relevant temperatures spans nearly five decades. The road to success demanded the development of the theory of wave propagation in high temperature plasma in complex magnetic field geometries, development of antenna structures and transmission lines capable of handling high RF powers, and the development of high power RF (microwave) sources. In the early days, progress was hindered by the lack of good confinement of energetic particles formed by high power RF wave-plasma interactions. For example, in the ion cyclotron resonance frequency regime (ICRF) ions with energies in the multi-100keV, or even MeV range may be formed due to the presence of efficient 'minority species' absorption. Electrons with similar energies can be formed upon the injection of RF waves in the electron cyclotron resonance (ECRH) or lower hybrid range of frequencies (LHRF) because of quasi-linear Landau (cyclotron) interactions between waves and particles. In this paper a summary of four decades of historical evolution of wave heating and current drive results will be given.

Porkolab, Miklos [Massachusetts Institute of Technology, Plasma Science and Fusion Center and Department of Physics, NW 16-288, 167 Albany Street, Cambridge, MA 02139 (United States)

2007-09-28T23:59:59.000Z

392

Defining the Proton Topology of the Zr6Based Metal-Organic Framework NU-1000  

E-Print Network (OSTI)

,16-19 heavy metal capture,20,21 sensing,12 ionic conductivity,22 toxic industrial chemical capture,23Defining the Proton Topology of the Zr6Based Metal-Organic Framework NU-1000 Nora Planas,, Joseph E of Science, King Abdulaziz University, Jeddah, Saudi Arabia *S Supporting Information ABSTRACT: Metal

393

High temperature ablation resistance of ZrNp reinforced W matrix composites  

E-Print Network (OSTI)

modulus of elasticity, good thermal shock resistance, stiffness and good high temperature strengthHigh temperature ablation resistance of ZrNp reinforced W matrix composites Malik Adeel Umer microscopy (SEM) For the purpose of improving the high temperature ablation resistance of tungsten

Hong, Soon Hyung

394

Oxide Electronic Conductivity and Hydrogen Pickup Fraction in Zr alloys Adrien Coueta  

E-Print Network (OSTI)

hydrogen ingress can cause cladding embrittlement and limit cladding lifetime. However, mechanisticOxide Electronic Conductivity and Hydrogen Pickup Fraction in Zr alloys Adrien Coueta , Arthur T, 77818 Moret-sur-Loing, France INTRODUCTION The hydrogen pick-up during cladding corrosion is a critical

Motta, Arthur T.

395

Chemical Synthesis of Pure and Gd-doped CaZrO3 Powders  

E-Print Network (OSTI)

5, 70569 Stuttgart, Germany Abstract Aqueous solutions of calcium chloride (CaCl2. 2H2O Starting chemicals used in this study were reagent- grade CaCl2.2H2O (Riedel de Haen), ZrOC12.8H2O (Merck

Tas, A. Cuneyt

396

IBM-1 calculations towards the neutron-rich nucleus {sup 106}Zr  

SciTech Connect

The neutron-rich N=66 isotonic and A=106 isobaric chains, covering regions with varying types of collectivity, are interpreted in the framework of the interacting boson model. Level energies and electric quadrupole transition probabilities are compared with available experimental information. The calculations for the known nuclei in the two chains are extrapolated toward the neutron-rich nucleus {sup 106}Zr.

Lalkovski, Stefan [Faculty of Physics, University of Sofia, Sofia, BG-1164 Bulgaria (Bulgaria); School of Environment and Technology, University of Brighton, Brighton BN2 4JG (United Kingdom); Grand Accelerateur National d'Ions Lourds, CEA/DSM-CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5 (France); Isacker, P. Van [Grand Accelerateur National d'Ions Lourds, CEA/DSM-CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5 (France)

2009-04-15T23:59:59.000Z

397

Phase Stability and Thermodynamic Assessment of the Np-Zr system  

E-Print Network (OSTI)

Metallic fuels have an important role to play in "fast breeder" Gen-IV type nuclear reactors, and U-Pu-Zr is one of the prototypical systems. Because of the variability in fuel chemistry during burn-up, it is important to understand the effect...

Bajaj, Saurabh

2012-02-14T23:59:59.000Z

398

Discovery of Critical Oxygen Content for Glass Formation in Zr80Pt20 Melt Spun Ribbons  

SciTech Connect

Zr{sub 80}Pt{sub 20} alloys may form meta-stable quasicrystals either during devitrification of an amorphous phase or directly upon cooling from a liquid depending on processing conditions. To date, little attention has been given to the role of oxygen on the glass formation or devitrification behavior of Zr-Pt and similar alloys. This study reveals that oxygen content during melt spinning indeed strongly influences the formation of the as-quenched structure. A critical amount of oxygen was found to be required to form amorphous ribbons at a fixed quench rate. At lower oxygen levels (i.e., <500 ppm mass), a fully crystallized is formed; the structure is composed mainly of meta-stable {beta}-Zr with a small fraction of a quasicrystalline phase. At higher oxygen levels, the as-quenched structure transitions to a fully amorphous structure ({approx}1000 ppm mass), and with further oxygen addition forms a mixture of amorphous and quasicrystalline ({approx}1500 ppm mass) or crystalline phases (>2500 ppm mass). Details regarding the structure of the meta-stable {beta}-Zr phase in the low-oxygen ribbons are provided along with a discussion of the structural similarity between this phase and the quasicrystal structure that formed in this alloy.

D.J. Sordelet; E.A. Rozhkova; X. Yang; M.J. Kramer

2004-09-30T23:59:59.000Z

399

Stress-corrosion fatiguecrack growth in a Zr-based bulk amorphous metal  

E-Print Network (OSTI)

of the work was to determine the rate and mechanisms of subcritical crack growth in this metallic glassStress-corrosion fatigue­crack growth in a Zr-based bulk amorphous metal V. Schroeder 1 , R. Results indicate that crack growth in aqueous solution in this alloy is driven by a stress-assisted anodic

Ritchie, Robert

400

Simultaneous observations of 46. 8-MHz and 430-MHz radar backscatter from HF-induced ionospheric Langmuir turbulence  

SciTech Connect

Simultaneous high-resolution spectra of the upshifted enhanced plasma line were obtained with the 46.8-MHz and 430-MHz Arecibo radars in the presence of HF transmissions at two closely spaced frequencies. The spectra obtained with the 46.8-MHz radar showed two narrow features with positive Doppler shifts equal to the two closely spaced frequencies of the HF transmissions; all the spectral power was contained in those two narrow features. The spectra obtained with the 430-MHz radar showed a single narrow feature with a positive Doppler shift equal to the arithmetic mean of the same two closely spaced frequencies; the spectral power in that narrow feature contained about 3% of the total spectral power. The present results broadly confirm the tentative interpretation of earlier observations with a 46.8-MHz radar at Arecibo. The results also show the fundamental difference in the physical processes leading to the enhanced plasma line spectra observed with the two radars.

Sulzer, M.P. (Arecibo Observatory (Puerto Rico)); Fejer, J.A. (Univ. of California, San Diego, La Jolla (United States))

1991-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Observation of a P-associated defect in Hf O 2 nanolayers on (100)Si by electron spin resonance  

Science Journals Connector (OSTI)

Electron spin resonance analysis has detected a P-donor related point defect in nanometer-thick Hf O 2 films on (100)Si after annealing in the range of 500 900 C . Based on the principal g matrix (axial; g ? = 1.9965 ; g ? = 1.9975 ) and hyperfine tensor values ( A 1 = 1425 10 G A 2 = 1245 10 G and A 3 = 1160 10 G ) inferred from consistent K - and Q -band spectrum simulations the center is assigned to a P 2 -type defecta P substituting a Hf atomsimilar to P 2 in silica where the unpaired spin is strongly localized on the P atom. The annealing impact is linked to the onset of crystallization enabling substitutional positioning of the P impurities. The centers may act as detrimental charge trapping sites.

K. Clmer; A. Stesmans; V. V. Afanasev

2007-01-01T23:59:59.000Z

402

First in-beam observation of excited states in {sup 156}{sub 72}Hf{sub 84} using the recoul-decay tagging method  

SciTech Connect

Excited states in the proton rich nuclide {sup 156}{sub 72}Hf{sub 84} were observed for the first time using the {sup 102}({sup 58}Ni, 2p2n){sup 156}Hf reaction at 270 MeV. Gamma rays were detected with the AYEBALL array of Compton suppressed Ge detectors, placed in front of the Fragment Mass Analyzer, and were assigned to individual reaction charmers using the Recoil-Decay Tagging Method. Prompt {gamma}-ray cascades were associated with the alpha decay of both the ground state and the 8{sup +} isomeric state in {sup 156}Hf. The level scheme constructed for {sup 156}Hf is compared with level schemes of lighter even-even N=84 isotones and is discussed within the framework of the Shell Model.

Seweryniak, D.; Ahmad, H.; Amro, D.J. [and others

1996-12-31T23:59:59.000Z

403

Self-assembly of Ni nanocrystals on HfO{sub 2} and N-assisted Ni confinement for nonvolatile memory application  

SciTech Connect

We demonstrate memory property using Ni nanocrystals with mean diameter of 9 nm embedded in HfO{sub 2} high-k dielectric that are formed via a self-assembly process by sputtering and rapid thermal annealing. X-ray photoelectron spectroscopy shows that Ni penetrates into the 5 nm HfO{sub 2} after high temperature annealing above 800 deg. C in N{sub 2}. However, the diffusion is suppressed by N incorporation into HfO{sub 2} by NH{sub 3} annealing. Metal-oxide-semiconductor structures were fabricated with Ni nanocrystals embedded in HfO{sub 2}. An additional counterclockwise hysteresis of 2.1 V due to the charge trapping properties of the Ni nanocrystals was observed from a {+-}5 V sweep during capacitance-voltage electrical measurement.

Tan, Zerlinda; Samanta, S.K.; Yoo, Won Jong; Lee, Sungjoo [Silicon Nano Device Laboratory, Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)

2005-01-03T23:59:59.000Z

404

New Coordination Compounds of Cd(AsF6)2 with HF and XeF2  

Science Journals Connector (OSTI)

New Coordination Compounds of Cd(AsF6)2 with HF and XeF2 ... The total fluoride content (Ftotal-) was determined after complete decomposition of the sample by fusion with KNaCO3. ... Raman spectra of the powdered samples in sealed quartz capillaries were recorded on a Renishaw Raman Imaging Microscope System 1000 by use of the 632.8 nm exciting line of a He?Ne laser. ...

Gaper Tav?ar; Primo Benki?; Boris emva

2004-01-21T23:59:59.000Z

405

Calculations of the cross sections for the neutron acceleration, slowing down, and capture by the isomer "OmHf  

E-Print Network (OSTI)

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

Shlyakhter, Ilya

406

Design Concepts for RF-DC Conversion in Particle Accelerator Systems  

E-Print Network (OSTI)

In many particle accelerators considerable amounts of RF power reaching the megawatt level are converted into heat in dummy loads. After an overview of RF power in the range 200 MHz to 1 GHz dissipated at CERN we discuss several developments that have come up in the past using vacuum tube technology for RF-DC conversion. Amongst those the developments of the cyclotron wave converter CWC appears most suitable. With the availability of powerful Schottky diodes the solid state converter aspect has to be addressed as well. One of the biggest problems of Schottky diode based structures is the junction capacity. GaAs and GaN Schottky diodes show a significant reduction of this junction capacity as compared to silicon. Small rectenna type converter units which have been already developed for microwave powered helicopters can be used in waveguides or with coaxial power dividers.

Caspers, F; Grudiev, A; Sapotta, H

2010-01-01T23:59:59.000Z

407

Cryogenic test of a proof-of-principle superconducting rf-dipole deflecting and crabbing cavity  

Science Journals Connector (OSTI)

Recent applications in need of compact low-frequency deflecting and crabbing cavities have initiated the design and development of new superconducting structures operating at high gradients with low losses. Previously, TM110-type deflecting and crabbing cavities were developed and have also been operated successfully. However, these geometries are not favorable designs for low operating frequencies. The superconducting rf-dipole cavity is the first compact deflecting and crabbing geometry that has demonstrated high gradients and high shunt impedance. Since the fundamental operating mode is the lowest mode and is widely separated from the nearest higher order mode, the rf-dipole design is an attractive geometry for effective damping of the higher order modes in high current applications. A 400MHz rf-dipole cavity was designed, fabricated, and tested as a proof-of-principle cavity. The cavity achieved high operating gradients, and the multipacting levels were easily processed and did not reoccur.

S. U. De Silva and J. R. Delayen

2013-08-16T23:59:59.000Z

408

Final Technical Report- Back-gate Field Emission-based Cathode RF Electron Gun  

SciTech Connect

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.

McGuire, Gary; Martin, Allen; Noonan, John

2010-10-30T23:59:59.000Z

409

RF transmission line and drill/pipe string switching technology for down-hole telemetry  

DOE Patents (OSTI)

A modulated reflectance well telemetry apparatus having an electrically conductive pipe extending from above a surface to a point below the surface inside a casing. An electrical conductor is located at a position a distance from the electrically conductive pipe and extending from above the surface to a point below the surface. Modulated reflectance apparatus is located below the surface for modulating well data into a RF carrier transmitted from the surface and reflecting the modulated carrier back to the surface. A RF transceiver is located at the surface and is connected between the electrically conductive pipe and the electrical conductor for transmitting a RF signal that is confined between the electrically conductive well pipe and the electrical conductor to the modulated reflectance apparatus, and for receiving reflected data on the well from the modulated reflectance apparatus.

Clark, David D. (Santa Fe, NM); Coates, Don M. (Santa Fe, NM)

2007-08-14T23:59:59.000Z

410

Solvated Electrons in Very Small Clusters of Polar Molecules: (HF)(3)(-): art. no. 143001  

SciTech Connect

A cluster of polar molecules can host an excess electron in at least two ways. First, the excess electron can be tethered to the cluster by its interaction with the cluster?s dipole moment. , Second, the electron can localize inside the cluster, bulk analogs being the hydrated and ammoniated electrons. - While the structural reorganization of the cluster, due to attachment of an excess electron, is typically small for dipole-bound electrons (dbe), it is usually quite significant for''solvated electrons'' (se), since the solvation occurs at the expense of breaking of pre-existing hydrogen bonds. The se structures, however, provide more contact interactions between the polar molecules and the excess electron. For these reasons, it is often assumed that dbe's dominate for small polar clusters, whereas large clusters form se's. Here we show that dbe's and se's coexist in as small a cluster as (HF)3-. The stability of these anions with respect to the neutral cluster results not only from the excess electron binding energy but also from favorable entropic effects, which reflect the greater ''floppiness'' of the anionic structures.

Gutowski, Maciej S. (BATTELLE (PACIFIC NW LAB)); Hall, C (Arizona, University Of); Adamowicz, L (Arizona, University Of); Hendricks, J.H. (Johns Hopkins Univ); De Clercq, Helen (Howard University); Lyapustina, S.A. (Johns Hopkins Univ); Nilles, J.M. (Johns Hopkins Univ); Xu, S.J. (Johns Hopkins Univ); Bowen Jr., K.H. (Johns Hopkins Univ)

2001-12-01T23:59:59.000Z

411

Temperature dependent structural, optical and hydrophobic properties of sputtered deposited HfO{sub 2} films  

SciTech Connect

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 400C.

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)

2014-01-28T23:59:59.000Z

412

Numerical simulation of a Q-switched cw chemical HF laser  

SciTech Connect

A mathematical model of a Q-switched cw chemical laser is developed. The model is based on a simplified description of the active medium and the exact wave description of the mode structure of radiation. The model is used to study numerically the spatial-angular parameters of the output beam of a HF laser. We considered an unstable cavity that provided a high stability of the axis of the laser-pulse radiation pattern upon Q-switching with the help of a rotating mirror. The results of numerical simulation showed that for typical dimensions of a plane or an unstable cavity of the positive branch in a cw chemical laser, the angular radiation divergence rapidly changes in time and on average exceeds the diffraction limit by an order of magnitude. The problem can be solved by replacing a rotating mirror Q switch by a fixed one with time-dependent transmission. We also considered a negative-branch unstable cavity which can provide a stable radiation divergence upon Q-switching produced by a rotating mirror. (lasers)

Kuprenyuk, V I [Institute for Laser Physics, Federal State Unitary Enterprise ' Scientific and Industrial Corporation 'Vavilov State Optical Institute', St. Petersburg (Russian Federation); Maksimov, Yurii P; Mashendzhinov, Viktor I; Rotinyan, Mikhail A; Fedorov, Igor' A [Russian Science Centre 'Applied Chemistry', St Petersburg (Russian Federation); Rodionov, A Yu

2007-03-31T23:59:59.000Z

413

Early (?4.5Ga) formation of terrestrial crust: LuHf, ?18O, and Ti thermometry results for Hadean zircons  

Science Journals Connector (OSTI)

Large deviations in ?Hf(T) from bulk silicate Earth seen in >4Ga detrital zircons from Jack Hills, Western Australia, have been interpreted as reflecting a major differentiation of the silicate Earth at 4.4 to 4.5Ga. We have expanded the characterization of 176Hf/177Hf initial ratios (Hf) in Hadean zircons by acquiring a further 116 laser ablation LuHf measurements on 87 grains with ion microprobe 207Pb/206Pb ages up to 4.36Ga. Most measurements employed concurrent LuHf and 207Pb/206Pb analyses, permitting assessment of the age of the volumetrically larger domain sampled by laser drilling against the spatially more restricted ion microprobe ages. Our new results confirm and extend the earlier observation of significant negative deviations in ?Hf(T) throughout the Hadean, although no positive ?Hf(T) values were documented in this study. Monte Carlo modelling of these data yields an essentially uniform spectrum of model ages between 4.56 and 4.20Ga for extraction of the zircons' protoliths from a chondritic reservoir. To assess whether the five data plotting close to solar system initial Hf (Hfo) are statistically robust, we derived the error propagation equation for a parameter, ?o, which measures the difference of a sample from Hfo. Our analysis suggests that this limited data is indicative of source sequestration in a crustal-type Lu/Hf environment prior to 4.5Ga. Oxygen isotope data and Ti thermometry from Hadean zircons show little obvious correlation with Hf, consistent with their derivation through fusion of a broad suite of crustal rock types under water-saturated conditions. Together with other isotopic and trace element data obtained from these ancient zircons, our results indicate essentially continuous derivation of crust from the mantle from 4.5 to 4.2Ga with concurrent recycling into the mantle and internal crustal re-working. These results represent further evidence that by 4.35Ga, portions of the crust had taken on continental characteristics.

T. Mark Harrison; Axel K. Schmitt; Malcolm T. McCulloch; Oscar M. Lovera

2008-01-01T23:59:59.000Z

414

Features of the band structure and conduction mechanisms in the n-HfNiSn semiconductor heavily doped with Ru  

SciTech Connect

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 = 80400 K and N{sub A}{sup Ru} ? 9.5 10{sup 19}?5.7 10{sup 20} cm{sup ?3} (x = 00.03), 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.

Romaka, V. A., E-mail: vromaka@polynet.lviv.ua [National Academy of Sciences of Ukraine, Pidstrygach Institute for Applied Problems in Mechanics and Mathematics (Ukraine); Rogl, P. [Universitt Wien, Institut fr Physikalische Chemie (Austria); Romaka, V. V. [National University Lvivska Politekhnika (Ukraine); Stadnyk, Yu. V. [Ivan Franko National University of Lviv (Ukraine); Korzh, R. O.; Krayovskyy, V. Ya. [National University Lvivska Politekhnika (Ukraine); Horyn, A. M. [Ivan Franko National University of Lviv (Ukraine)

2014-12-15T23:59:59.000Z

415

Highly efficient dye-sensitized solar cells based on HfO{sub 2} modified TiO{sub 2} electrodes  

SciTech Connect

Graphical abstract: Display Omitted Highlights: ? HfO{sub 2} has been used to modify TiO{sub 2} electrodes in dye sensitized solar cells. ? HfO{sub 2} layer increases the dye adsorption. ? Diffusion coefficient (D{sub e}) and lifetime (?{sub e}) of the photoelectrons were increased. ? Solar cell efficiency (?) was greatly improved from 5.67 to 9.59%. -- Abstract: In this article, we describe the use of hafnium oxide (HfO{sub 2}) as a new and efficient blocking layer material to modify TiO{sub 2} electrodes in dye sensitized solar cells. Different thicknesses of HfO{sub 2} over-layers were prepared by simple dip coating from two different precursors and their effects on the performance of DSSCs were studied. The HfO{sub 2} modification remarkably increases dye adsorption, resulting from the fact that the surface of HfO{sub 2} is more basic than that of TiO{sub 2}. Furthermore, the HfO{sub 2} coating demonstrated increased diffusion coefficient (D{sub e}) and lifetime (?{sub e}) of the photoelectrons, indicating the improved retardation of the back electron transfer, which increases short-circuit current (J{sub sc}) and open-circuit voltage (V{sub oc}). Thereby, the photo conversion efficiency (?) of the solar cell was greatly improved from 5.67 to 9.59% (an improvement of 69.02%) as the HfO{sub 2} layer was coated over TiO{sub 2} films.

Ramasamy, Parthiban [Department of Chemistry and GETRC, Kongju National University, 182 Singkwan, Kongju, Chungnam 314-701 (Korea, Republic of)] [Department of Chemistry and GETRC, Kongju National University, 182 Singkwan, Kongju, Chungnam 314-701 (Korea, Republic of); Kang, Moon-Sung; Cha, Hyeon-Jung [Department of Environmental Engineering, Sangmyung University, 300 Anseo-dong, Dongnam-gu, Cheonan-si, Chungnam 330-720 (Korea, Republic of)] [Department of Environmental Engineering, Sangmyung University, 300 Anseo-dong, Dongnam-gu, Cheonan-si, Chungnam 330-720 (Korea, Republic of); Kim, Jinkwon, E-mail: jkim@kongju.ac.kr [Department of Chemistry and GETRC, Kongju National University, 182 Singkwan, Kongju, Chungnam 314-701 (Korea, Republic of)] [Department of Chemistry and GETRC, Kongju National University, 182 Singkwan, Kongju, Chungnam 314-701 (Korea, Republic of)

2013-01-15T23:59:59.000Z

416

Titanium nitride thin films deposited by reactive pulsed-laser ablation in RF plasma  

Science Journals Connector (OSTI)

Titanium nitride thin films were deposited on Si (100) substrates by pulsed laser ablation of a titanium target in a N2 atmosphere (gas pressure approx. 10 Pa) using a doubled frequency Nd:YAG laser (532 nm) also assisted by a 13.56-MHz radio frequency (RF) plasma. Deposition was carried out at various substrate temperatures ranging from 373 up to 873 K and films were analyzed by X-ray diffractometry, scanning electron microscopy and optical emission spectroscopy. A comparison between the normal pulsed laser deposition (PLD) and the RF plasma-assisted PLD showed the influence of the plasma on the structural characteristics of the thin films.

A. Giardini; V. Marotta; S. Orlando; G.P. Parisi

2002-01-01T23:59:59.000Z

417

Plasma sweeper to control the coupling of RF power to a magnetically confined plasma  

DOE Patents (OSTI)

A device for coupling RF power (a plasma sweeper) from a phased waveguide array for introducing RF power to a plasma having a magnetic field associated therewith comprises at least one electrode positioned near the plasma and near the phased waveguide array; and a potential source coupled to the electrode for generating a static electric field at the electrode directed into the plasma and having a component substantially perpendicular to the plasma magnetic field such that a non-zero vector cross-product of the electric and magnetic fields exerts a force on the plasma causing the plasma to drift.

Motley, Robert W. (Princeton, NJ); Glanz, James (Lawrenceville, NJ)

1985-01-01T23:59:59.000Z

418

Structure and dielectric properties of La{sub x}Hf{sub (1?x)}O{sub y} thin films: The dependence of components  

SciTech Connect

Graphical abstract: - Highlights: La{sub x}Hf{sub (1?x)}O{sub y} thin films were grown by pulse laser deposition method. The thin film with 10% La/(La + Hf) atom ratio forms a cubic HfO{sub 2} phase. The amorphous thin films due to more La introduced have almost same local structure. The main infrared phonon modes move to lower frequency for the amorphous thin films. The static dielectric constants of the amorphous thin films increase with La content. - Abstract: La{sub x}Hf{sub (1?x)}O{sub y} (x = 0, 0.1, 0.3, 0.5, 0.7, y=2?(1/2)x) thin films were grown by pulsed laser deposition (PLD) method. The component dependence of the structure and vibration properties of these thin films is studied by combining X-ray diffraction, X-ray absorption fine structure (XAFS) and infrared spectroscopy. The thin film with 10% La/(La + Hf) atom ratio forms a cubic HfO{sub 2} phase and it has the largest static dielectric constant. More La atoms introduced cause amorphous phase formed and the static dielectric constants increase with the La content. Although XAFS indicates that these amorphous thin films have almost same local structures, the infrared phonon modes with most contribution to the static dielectric constant move to lower frequency, which results in the component dependence of the dielectric constant.

Qi, Zeming, E-mail: zmqi@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China); Cheng, Xuerui [Department of Technology and Physics, Zhengzhou University of Light Industry, Zhengzhou, Henan 450002 (China); Zhang, Guobin [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China); Li, Tingting [Institute of Microelectronics of Chinese Academy of Science, Beijing 100029 (China); Wang, Yuyin; Shao, Tao; Li, Chengxiang; He, Bo [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China)

2013-07-15T23:59:59.000Z

419

Electroerosion resistance and structural phase transformations in electrospark and laser deposition of titanium alloys using composite ceramics based on ZrB2-ZrSi2 and TiN-Cr3C2 systems  

Science Journals Connector (OSTI)

The paper examines the mass transfer kinetics, structure, phase and chemical compositions, and micromechanical properties of electrospark and laser coatings on titanium alloys (including...2-ZrSi2 and TiN-Cr3C2 s...

I. A. Podchernyaeva; A. D. Panasyuk

2008-01-01T23:59:59.000Z

420

Real-time imaging of the spatial distribution of rf-heating in NMR samples during broadband decoupling  

E-Print Network (OSTI)

by the temperature control system. Moreover, as the heating is spatially inhomogeneous, higher temperature increases of the numerical simulations. Since electric fields manifest themselves by rf-heating, the E-field distributionReal-time imaging of the spatial distribution of rf-heating in NMR samples during broadband

Wider, Gerhard

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

APS DPP Meeting, Quebec City Canada R V Budny 2327 October 2000 Comparison of RF-heated with  

E-Print Network (OSTI)

42 nd APS DPP Meeting, Quebec City Canada R V Budny 23­27 October 2000 JG00.293/1 Comparison of RF 2000 JG00.293/3 Conclusions Motivation ICRH ­ heated ELMy plasmas are suggested for reactor startup heated ELMy plasmas Heating power lower than desired (close to L-mode) VTor for RF in Co-Ip direction

Budny, Robert

422

Open-Thru de-embedding for Graphene RF devices Giancarlo Vincenzi, George Deligeorgis, Fabio Coccetti and Patrick Pons  

E-Print Network (OSTI)

Open-Thru de-embedding for Graphene RF devices Giancarlo Vincenzi, George Deligeorgis, Fabio, LAAS, F-31400 Toulouse, France Abstract--The performances of graphene RF devices rely heavily-embedding technique adapted to the needs of microwave graphene devices is presented. Two standards and only one step

Boyer, Edmond

423

SPECIFICATION FOR A RF SHIELDED ENCLOSURE 1. Scope -This specification covers the general requirements for the design, construction,  

E-Print Network (OSTI)

the following: a. Architecturally styled RF doors and windows. b. RF attenuating filters for power, telephone. Honeycomb grills for HVAC vents and floor drains. g. Conductive metallized fabric or copper foil on walls, and filter insertion loss should be tailored to meet the actual needs of the owner. Furthermore

Groppi, Christopher

424

Nano-fabricated superconducting radio-frequency composites, method for producing nano-fabricated superconducting rf composites  

DOE Patents (OSTI)

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.

Norem, James H.; Pellin, Michael J.

2013-06-11T23:59:59.000Z

425

Methane Combustion over Pd/ZrO2/SiC, Pd/CeO2/SiC, Pd/Zr0.5Ce0.5O2/SiC Catalysts  

E-Print Network (OSTI)

1 Methane Combustion over Pd/ZrO2/SiC, Pd/CeO2/SiC, Pd/Zr0.5Ce0.5O2/SiC Catalysts Xiaoning Guo a Laboratory of Coal Conversion, Institute of Coal Chemistry, Taiyuan 030001, PR China b GREMI UMR6606 CNRS0.5O2 solid solution) modified Pd/SiC catalysts for methane combustion are studied. XRD and XPS

Paris-Sud XI, Université de

426

Production of 1-m size uniform plasma by modified magnetron-typed RF discharge with a subsidiary electrode for resonance  

Science Journals Connector (OSTI)

A large-diameter uniform plasma of 1 m in size is produced using a modified magnetron-typed (MMT) RF plasma source at the frequency of 13.56 MHz. The construction and operation of the MMT RF plasma source are very simple and we can place two substrates simultaneously. To achieve an efficient production of high density plasma, a parallel resonance circuit is connected to one of the substrates which acts as a subsidiary RF electrode controlling the plasma parameters. In the case of the resonance the plasma density increases to approximately three times as much as that in case of non-resonance. The plasma density reaches?11011/cm3 in Ar at 1 mtorr when the RF input power is 2.8 kW. The MMT RF plasma source provides a plasma with uniformity within several percent over 1 m in diameter in front of the substrate in the low gas pressure regime.

Yuji Urano; Yunlong Li; Keiichi Kanno; Satoru Iizuka; Noriyoshi Sato

1998-01-01T23:59:59.000Z

427

Improved nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging  

DOE Patents (OSTI)

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.

Fukushima, E.; Roeder, S.B.W.; Assink, R.A.; Gibson, A.A.V.

1984-01-01T23:59:59.000Z

428

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

E-Print Network (OSTI)

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

Qiang, J.

2010-01-01T23:59:59.000Z

429

Simulation and characterization of Cylindrical RF cavity with output section coupling for 250 kW CW C-band klystron  

Science Journals Connector (OSTI)

The klystron is a microwave tube capable to produce very high power that find wide use in communication, radar, material processing, particle accelerators and thermonuclear fusion reactors. The RF section has an important role in deciding the RF performance ...

O. S. Lamba; Meenu Kaushik; L. M. Joshi; Rakesh Meena; Debasish Pal; Vishnu Jindal; Priyanka Jangir; Vijay Singh; Sunit Kumar; Depender Kant

2011-02-01T23:59:59.000Z

430

Certain peculiarities of Zr?Cr?N coatings on steel blades of a gas-turbine engine compressor  

Science Journals Connector (OSTI)

The properties of compressor blades of a helicopter gas-turbine engine with an experimental ionplasma coating Zr? ... -resistant, and mitigate the dependence of their residual properties on the amplitude and the ...

V. A. Styazhkin; A. A. Kopylov; S. Ya. Paleeva; Yu. G. Veksler

431

Frequency-feedback tuning for single-cell cavity under rf heating  

SciTech Connect

A tuning system is described that is being used to match the source frequency of a high-power klystron on the resonant frequency of the prototype single-cell cavity for the 7-GeV Advance Photon Source (APS) storage ring. Typically a water-cooled piston tuner is required to adjust the reactive component of the cavity`s impedance to minimize reflected power back to the RF drive source. As the cavity watts expand due to RF heating, the resonant frequency decreases. Adjusting the source frequency to follow the cavity resonant frequency is a convenient method used to condition the cavity (for vacuum) at high power levels, in this case, 1 MV gap voltage at 100 kW power level. The tuning system consists of two coupling ports, a phase detector, a digitizing I/O system, and a DC coupled FM-modulated RF source. Proportional Integral Derivative (PID) loop parameters for the Experimental Physics and Industrial Control System (EPICS) software are calculated, and data is presented showing the damped response to peturbations on the loop. The timing system presented here does not need water-cooling, has no moving parts to wear out, and has an inherently faster response time. Its one limitation is the digitizing sampling rate. The only limitation in tuning range is the bandwidth of the RF source.

Stepp, J.D.; Bridges, J.F.

1993-08-01T23:59:59.000Z

432

Aluminum nitride for heatspreading in RF IC's L. La Spina a,*, E. Iborra b  

E-Print Network (OSTI)

phenomena Heatspreader Piezoelectric characteristics RF integration Thermal instabilities Thermal resistance that display a reduc- tion of more than 70% in the value of the thermal resistance. ? 2008 Elsevier Ltd. All lead to a very high thermal resistance. This has been demonstrated in our in-house silicon-on- glass

Technische Universiteit Delft

433

Ion Crystals Produced by Laser and Sympathetic Cooling in a Linear RF Ion Trap  

E-Print Network (OSTI)

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...

Zhu, Feng

2012-02-14T23:59:59.000Z

434

Synthesis and Diagnosis of RF Filters in Liquid Crystalline Polymer (LCP) Substrate  

E-Print Network (OSTI)

Synthesis and Diagnosis of RF Filters in Liquid Crystalline Polymer (LCP) Substrate Souvik-consuming step in the manufacturing cycle. This paper presents the application of layout-level synthesis synthesized and fabricated. The results of synthesis are within 5% of EM measurement data. The fabricated

Swaminathan, Madhavan

435

Heterogeneous PLC-RF networking for LLNs Cdric Chauvenet*,** --Bernard Tourancheau*  

E-Print Network (OSTI)

Heterogeneous PLC-RF networking for LLNs Cédric Chauvenet*,** -- Bernard Tourancheau* * CITI INSA and city automation, our view of the future building networking infrastructure places PLC as the central point. Thanks to the design of converging IPv6 networking layers, we show that merging PLC with existing

Paris-Sud XI, Université de

436

Experimental Studies of RF Interference and Upset in Devices and Gates  

E-Print Network (OSTI)

Xingzhi Wen #12;Goals · Start with the study of the effects on the fundamental units of IC circuits, ie and protecting elements. · Develop on-chip sensing, registration, and protection circuitry. #12;Effects. · Effective protection and RF hardened design will be developed #12;RFI Effect on Diode I-V Characteristics

Anlage, Steven

437

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens and Katia Sycara  

E-Print Network (OSTI)

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

Scerri, Paul

438

Airborne release fraction -ARF- and respirable fraction -RF- for foot pack cans in fires  

SciTech Connect

The purpose of this analysis is to provide the airborne release fraction (ARF), respirable fraction (RF) and respirable release as a fraction of initial mass for Food Pack Cans (FPCs) containing plutonium powders (e.g., oxide) that become pressurized to the point of bursting in a fire.

CARSON, D.M.

2002-06-05T23:59:59.000Z

439

Influence of Intense Beam in High Pressure Hydrogen Gas Filled RF Cavities  

SciTech Connect

The influence of an intense beam in a high-pressure gas filled RF cavity has been measured by using a 400 MeV proton beam in the Mucool Test Area at Fermilab. The ionization process generates dense plasma in the cavity and the resultant power loss to the plasma is determined by measuring the cavity voltage on a sampling oscilloscope. The energy loss has been observed with various peak RF field gradients (E), gas pressures (p), and beam intensities in nitrogen and hydrogen gases. Observed RF energy dissipation in single electron (dw) in N{sub 2} and H{sub 2} gases was 2 10{sup -17} and 3 10{sup -17} Joules/RF cycle at E/p = 8 V/cm/Torr, respectively. More detailed dw measurement have been done in H{sub 2} gas at three different gas pressures. There is a clear discrepancy between the observed dw and analytical one. The discrepancy may be due to the gas density effect that has already been observed in various experiments.

Yonehara, K.; Chung, M.; Collura, M.G.; Jana, M.R.; Leonova, M.; Moretti, A.; Popovic, M.; Schwarz, T.; Tollestrup, A.; /Fermilab; Johnson, R.P.; Franagan, G.; /Muons, Inc. /IIT

2012-05-01T23:59:59.000Z

440

Detachment-induced electron production in the early afterglow of pulsed cc-rf oxygen plasmas  

SciTech Connect

Line integrated electron densities are measured by 160.28 GHz Gaussian beam microwave interferometry in a 10 Hz pulsed (50% duty cycle) cc-rf oxygen discharge, operating at 13.56 MHz. Depending on the processing parameters, the oxygen rf discharge displays two different operation modes regarding its electronegativity. For higher rf power with negative self-bias voltage above -220 V, the oxygen discharge acts as electropositive plasma (n{sub -}/n{sub e} Much-Less-Than 1), whereas at lower rf power and self-bias voltage the plasma becomes strongly electronegative (n{sub -}/n{sub e}>2). In the latter mode, a significant electron density increase is measured in the early afterglow (<100 {mu}s) within a pressure range from 20 to 100 Pa. By use of a simple rate equation model, the temporal behavior of the electron density could be reproduced for both modes of electronegativity. The electron production in the early afterglow is mainly caused due to the detachment of negative atomic oxygen ions by metastable oxygen molecules.

Kuellig, C.; Dittmann, K.; Meichsner, J. [University of Greifswald, Institute of Physics, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany)

2012-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron  

E-Print Network (OSTI)

Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron Abstract-- Barium strontium titanate is a solid solution perovskite with a field-dependent permittivity.7 MV/cm. I. INTRODUCTION In recent years there has been much interest in thin-film barium strontium

York, Robert A.

442

High Power RF Tests on WR650 Pre-Stressed Planar Windows  

SciTech Connect

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.

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

2009-11-01T23:59:59.000Z

443

Thin crystalline silicon solar cells based on epitaxial films grown at 165C by RF PECVD  

E-Print Network (OSTI)

1 Thin crystalline silicon solar cells based on epitaxial films grown at 165°C by RF PECVD Romain temperatures. Keywords : Low temperature, epitaxy, PECVD, Si thin film, Solar cell hal-00749873,version1-25Nov shortage until 2010. Research on epitaxial growth for thin film crystalline silicon solar cells has gained

444

Thin crystalline silicon solar cells based on epitaxial films grown at 165C by RF PECVD  

E-Print Network (OSTI)

1 Thin crystalline silicon solar cells based on epitaxial films grown at 165°C by RF PECVD Romain temperatures. Keywords : Low temperature, epitaxy, PECVD, Si thin film, Solar cell #12;2 1. Introduction: martin.labrune@polytechnique.edu ABSTRACT We report on heterojunction solar cells whose thin intrinsic

445

International Conference on Microwave and RF Heating MODELING OF A CYLINDRICAL APPLICATOR WITH THE  

E-Print Network (OSTI)

by comprehensive modeling specifying appropriate parameters of the excitation system and monitoring the electric10th International Conference on Microwave and RF Heating and experimentally. It appears that because of the uniform electric field distribution along the axis of the cylinder

Yakovlev, Vadim

446

CMOS RF down-conversion mixer design for low-power wireless communications  

E-Print Network (OSTI)

and the digital building blocks on a single chip. Indeed, both the full integration and the low-voltage design, 1 building blocks This paper aims to study the design of an integrated single-balanced mixer in CMOS 0.18 !m for the design of RF integrated circuits. Indeed, in recent years the huge efforts, provided

Paris-Sud XI, Université de

447

Development of fundamental power coupler for high-current superconducting RF cavity  

SciTech Connect

Brookhaven National Laboratory took a project of developing a 704 MHz five-cell superconducting RF cavity for high-current linacs, including Energy Recovery Linac (ERL) for planned electron-hadron collider eRHIC. The cavity will be fed by a high-power RF amplifier using a coaxial Fundamental Power Coupler (FPC), which delivers 20 kW of CW RF power to the cavity. The design of FPC is one of the important aspects as one has to take into account the heat losses dissipated on the surface of the conductor by RF fields along with that of the static heat load. Using a simple simulation model we show the temperature profile and the heat load dissipated along the coupler length. To minimize the heat load on FPC near the cavity end, a thermal intercept is required at an appropriate location on FPC. A 10 K intercept was chosen and its location optimized with our simulation code. The requirement on the helium gas flow rate for the effective heat removal from the thermal intercept is also discussed.

Jain P.; Belomestnykh, S.; Ben-Zvi, I.; Xu, W.

2012-05-20T23:59:59.000Z

448

Analytical model for ion angular distribution functions at rf biased surfaces with collisionless plasma sheaths  

E-Print Network (OSTI)

Analytical model for ion angular distribution functions at rf biased surfaces with collisionless plasma sheaths Laxminarayan L. Rajaa) Department of Aerospace Engineering and Engineering Mechanics The article presents an analytical model for evaluation of ion angular distribution functions IADFs at a radio

Raja, Laxminarayan L.

449

ION HEATING WITH RF FIELDS NEAR THE ION CYCLOTRON FREQUENCY J. D. Barter, J. C. Sprott  

E-Print Network (OSTI)

ION HEATING WITH RF FIELDS NEAR THE ION CYCLOTRON FREQUENCY by J. D. Barter, J. C. Sprott November. Our experiments of the past year, however, indicate that ion cyclotron resonance heating transmitted without consent of the author and major professor. #12;For several years we have been heating ions

Sprott, Julien Clinton

450

A 900MHz RF Energy Harvesting Module TARIS Thierry, VIGNERAS Valrie  

E-Print Network (OSTI)

harvesting. Different types of source are considered among them are: wind, solar, vibration, temperature and everywhere". It is a decisive asset to address power saving and energy management challenges in WSN with the state of art. II. BUILDING BLOCK DESIGN AND CHARACTERISTICS Figure 1. Building blocks of the RF

Paris-Sud XI, Université de

451

The Effect of rf-Irradiation on Electrochemical Deposition and Its Stabilization by Nanoparticle Doping  

E-Print Network (OSTI)

studied microscale singular perturbation mechanisms in the deposit surface tension and attachment kineticsThe Effect of rf-Irradiation on Electrochemical Deposition and Its Stabilization by Nanoparticle resulted from singular effects of gas-filled submicrometer bubbles or nanobubbles, which are generated

Jacob, Eshel Ben

452

The effect of rf-irradiation on electrochemical deposition and its stabilization by nanoparticle doping  

E-Print Network (OSTI)

(surface tension and attachment kinetics). We also studied electrochemical deposition in Zinc sulphateThe effect of rf-irradiation on electrochemical deposition and its stabilization by nanoparticle that these changes of patterning on all scales resulted from singular effects of gas-filled submicron bubbles

Jacob, Eshel Ben

453

RF Plasma Cathode-Neutralizer for Space Applications IEPC-2007-266  

E-Print Network (OSTI)

Raitses and Nathaniel J. Fisch Princeton Plasma Physics Laboratory, Princeton, NJ 08543, USA AbstractRF Plasma Cathode-Neutralizer for Space Applications IEPC-2007-266 Presented at the 30th: A new plasma cathode-neutralizer based on electron extraction from inductively coupled plasma (ICP

454

Low ion energy RF reactor using an array of plasmas through a grounded grid  

SciTech Connect

A reactor using localized remote plasma in a grid electrode is presented in this study. The aim is to reduce the ion bombardment energy inherent in RF capacitively coupled parallel plate reactors used to deposit large area thin film silicon solar cells. High ion bombardment energy could cause defects in silicon layers and deteriorate electrical interfaces, therefore, by reducing the ion bombardment energy, lower defect density might be obtained. In this study, the low ion bombardment energy results from the reactor design. By inserting a grounded grid close to the RF electrode of a parallel plate reactor, the electrode area asymmetry is increased while retaining the lateral uniformity required for large area deposition. This asymmetry causes a strong negative self-bias voltage, which reduces the time-averaged plasma potential and thus lowers the ion bombardment energy. In addition to the self-bias, the time evolution of plasma light emission and plasma potential RF waveform are also affected by the grid, thereby further reducing the time-averaged plasma potential and ion bombardment energy. Finally, a good correlation between the measured time-averaged plasma potential and measured low ion bombardment energy is found in a broad range of RF voltages.

Chesaux, Michaeel; Howling, Alan A.; Hollenstein, Christoph [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Domine, Didier; Kroll, Ulrich [Oerlikon Solar-Lab SA, rue du Puits-Godet 12a, CH-2000 Neuchatel (Switzerland)

2013-03-15T23:59:59.000Z

455

Low-frequency RF Coupling To Unconventional (Fat Unbalanced) Dipoles  

SciTech Connect

The report explains radio frequency (RF) coupling to unconventional dipole antennas. Normal dipoles have thin equal length arms that operate at maximum efficiency around resonance frequencies. In some applications like high-explosive (HE) safety analysis, structures similar to dipoles with ''fat'' unequal length arms must be evaluated for indirect-lightning effects. An example is shown where a metal drum-shaped container with HE forms one arm and the detonator cable acts as the other. Even if the HE is in a facility converted into a ''Faraday cage'', a lightning strike to the facility could still produce electric fields inside. The detonator cable concentrates the electric field and carries the energy into the detonator, potentially creating a hazard. This electromagnetic (EM) field coupling of lightning energy is the indirect effect of a lightning strike. In practice, ''Faraday cages'' are formed by the rebar of the concrete facilities. The individual rebar rods in the roof, walls and floor are normally electrically connected because of the construction technique of using metal wire to tie the pieces together. There are two additional requirements for a good cage. (1) The roof-wall joint and the wall-floor joint must be electrically attached. (2) All metallic penetrations into the facility must also be electrically connected to the rebar. In this report, it is assumed that these conditions have been met, and there is no arcing in the facility structure. Many types of detonators have metal ''cups'' that contain the explosives and thin electrical initiating wires, called bridge wires mounted between two pins. The pins are connected to the detonator cable. The area of concern is between the pins supporting the bridge wire and the metal cup forming the outside of the detonator. Detonator cables usually have two wires, and in this example, both wires generated the same voltage at the detonator bridge wire. This is called the common-mode voltage. The explosive component inside a detonator is relatively sensitive, and any electrical arc is a concern. In a safety analysis, the pin-to-cup voltage, i.e., detonator voltage, must be calculated to decide if an arc will form. If the electric field is known, the voltage between any two points is simply the integral of the field along a line between the points. Eq. 1.1. For simplicity, it is assumed that the electric field and dipole elements are aligned. Calculating the induced detonator voltage is more complex because of the field concentration caused by metal components. If the detonator cup is not electrically connected to the metal HE container, the portion of the voltage generated by the dipole at the detonator will divide between the container-to-cup and cup-to-pin gaps. The gap voltages are determined by their capacitances. As a simplification, it will be assumed the cup is electrically attached, short circuited, to the HE container. The electrical field in the pin-to-cup area is determined by the field near the dipole, the length of the dipole, the shape of the arms, and the orientation of the arms. Given the characteristics of a lightning strike and the inductance of the facility, the electric fields in the ''Faraday cage'' can be calculated. The important parameters for determining the voltage in an empty facility are the inductance of the rebars and the rate of change of the current, Eq. 1.3. The internal electric fields are directly related to the facility voltages, however, the electric fields in the pin-to-cup space is much higher than the facility fields because the antenna will concentrate the fields covered by the arms. Because the lightning current rise-time is different for every strike, the maximum electric field and the induced detonator voltage should be described by probability distributions. For pedantic purposes, the peak field in the simulations will be simply set to 1 V/m. Lightning induced detonator voltages can be calculated by scaling up with the facility fields. Any metal object around the explosives, such as a work stand, will also distort the electric

Ong, M M; Brown, C G; Perkins, M P; Speer, R D; Javedani, J B

2010-12-07T23:59:59.000Z

456

Experimental observation of breakdowns in the Fermilab RF Gun G4 J.-P. Carneiro1, D. Edwards2, I. Gonin2, S. Schreiber1  

E-Print Network (OSTI)

Experimental observation of breakdowns in the Fermilab RF Gun G4 J.-P. Carneiro1, D. Edwards2, I Fermilab has developed and delivered to DESY Hamburg two RF guns for the operation of the phase I of the TESLA Test Facility (TTF) accelerator. The first RF gun (designated G3 in the following) has been

457

Design ad Modeling of a 17 GHz Photcxxthode RF Gun C. L. Lin, S. C. Chen, J. S. U'urtele, H. Temkin, 13. Danly *  

E-Print Network (OSTI)

Design ad Modeling of a 17 GHz Photcxxthode RF Gun C. L. Lin, S. C. Chen, J. S. U'urtele, H. Temkin of a high-frequencv(l7GHz), high accel- erating gradirnt(250hlv/rrl) photocathode RF gun is stud- ied in conventional DC guns followed by RF bunchers have reached their intrin- sic limitations and do not meet

Wurtele, Jonathan

458

DENSITY-FUNCTIONAL STUDY OF U-Mo AND U-Zr ALLOYS  

SciTech Connect

Density-functional theory previously used to describe phase equilibria in U-Zr alloys [A. Landa, P. Soederlind, P.E.A. Turchi, J. Alloys Comp. 478 (2009) 103-110] is extended to investigate the ground-state properties of U-Mo solid solutions. We discuss how the heat of formation in both alloys correlates with the charge transfer between the alloy components, and how the specific behavior of the density of states in the vicinity of the Fermi level promotes the stabilization of the U{sub 2}Mo compound. Our calculations prove that, due to the existence of a single {gamma}-phase over the typical fuel operation temperatures, {gamma}-U-Mo alloys should indeed have much lower constituent redistribution than {gamma}-U-Zr alloys for which binodal decomposition causes a high degree of constituent redistribution.

Landa, A; Soderlind, P; Turchi, P A

2010-11-01T23:59:59.000Z

459

Quantum Phase Transitions in the Itinerant Ferromagnet ZrZn2  

Science Journals Connector (OSTI)

We report a study of the ferromagnetism of ZrZn2, the most promising material to exhibit ferromagnetic quantum criticality, at low temperatures T as a function of pressure p. We find that the ordered ferromagnetic moment disappears discontinuously at pc=16.5???kbar. Thus a tricritical point separates a line of first order ferromagnetic transitions from second order (continuous) transitions at higher temperature. We also identify two lines of transitions of the magnetization isotherms up to 12T in the p-T plane where the derivative of the magnetization changes rapidly. These quantum phase transitions (QPT) establish a high sensitivity to local minima in the free energy in ZrZn2, thus strongly suggesting that QPT in itinerant ferromagnets are always first order.

M. Uhlarz; C. Pfleiderer; S. M. Hayden

2004-12-14T23:59:59.000Z

460

Devitrification kinetics and phase selection mechanisms in Cu-Zr metallic glasses  

SciTech Connect

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.

Kalay, Ilkay

2010-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "zr hf rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Air Oxidation Kinetics for Zr-based Alloys [Corrosion and Mechanics of  

NLE Websites -- All DOE Office Websites (Extended Search)

Air Oxidation Kinetics for Air Oxidation Kinetics for Zr-based Alloys Capabilities Materials Testing Environmentally Assisted Cracking (EAC) of Reactor Materials Corrosion Performance/Metal Dusting Overview Light Water Reactors Fatigue Testing of Carbon Steels and Low-Alloy Steels Environmentally Assisted Cracking of Ni-Base Alloys Irradiation-Induced Stress Corrosion Cracking of Austenitic Stainless Steels Steam Generator Tube Integrity Program Air Oxidation Kinetics for Zr-based Alloys Fossil Energy Fusion Energy Metal Dusting Publications List Irradiated Materials Steam Generator Tube Integrity Other Facilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Corrosion and Mechanics of Materials Light Water Reactors Bookmark and Share

462

Theoretical Predictions and Experimental Assessments of the Performance of Alumina RF Windows  

SciTech Connect

Radio frequency (RF) windows are the most likely place for catastrophic failure to occur in input power couplers for particle accelerators. Reliable RF windows are essential for the success of the Accelerator Production of Tritium (APT) program because there are over 1000 windows on the accelerator, and it takes more than one day to recover from a window failure. The goals of this research are to analytically predict the lifetime of the windows, to develop a conditioning procedure, and to evaluate the performance of the RF windows. The analytical goal is to predict the lifetime of the windows. The probability of failure is predicted by the combination of a finite element model of the window, Weibull probabilistic analysis, and fracture mechanics. The window assembly is modeled in a finite element electromagnetic code in order to calculate the electric fields in the window. The geometry (i.e. mesh) and electric fields are input into a translator program to generate the mesh and boundary conditions for a finite element thermal structural code. The temperatures and stresses are determined in the thermal/structural code. The geometry and thermal structural results are input into another translator program to generate an input file for the reliability code. Material, geometry and service data are also input into the reliability code. To obtain accurate Weibull and fatigue data for the analytical model, four point bend tests were done. The analytical model is validated by comparing the measurements to the calculations. The lifetime of the windows is then determined using the reliability code. The analytical model shows the window has a good thermal mechanical design and that fast fracture is unlikely to occur below a power level of 9 Mw. The experimental goal is to develop a conditioning procedure and evaluate the performance of RF windows. During the experimental evaluation, much was learned about processing of the windows to improve the RF performance. Methods of processing included grit blasting and using various coatings.

Karen Ann Cummings

1998-07-01T23:59:59.000Z

463

Thermal response of Ru electrodes in contact with SiO{sub 2} and Hf-based high-k gate dielectrics  

SciTech Connect

A systematic experimental evaluation of the thermal stability of Ru metal gate electrodes in direct contact with SiO{sub 2} and Hf-based dielectric layers was performed and correlated with electrical device measurements. The distinctly different interfacial reactions in the Ru/SiO{sub 2}, Ru/HfO{sub 2}, and Ru/HfSiO{sub x} film systems were observed through cross-sectional high-resolution transmission electron microscopy, high angle annular dark field scanning transmission electron microscopy with electron-energy-loss spectra, and energy dispersive x-ray spectra analysis. Ru interacted with SiO{sub 2}, but remained stable on HfO{sub 2} at 1000 deg. C. The onset of Ru/SiO{sub 2} interfacial interactions is identified via silicon substrate pitting possibly from Ru diffusion into the dielectric in samples exposed to a 900 deg. C/10-s anneal. The dependence of capacitor device degradation with decreasing SiO{sub 2} thickness suggests Ru diffuses through SiO{sub 2}, followed by an abrupt, rapid, nonuniform interaction of ruthenium silicide as Ru contacts the Si substrate. Local interdiffusion detected on Ru/HfSiO{sub x} samples may be due to phase separation of HfSiO{sub x} into HfO{sub 2} grains within a SiO{sub 2} matrix, suggesting that SiO{sub 2} provides a diffusion pathway for Ru. Detailed evidence consistent with a dual reaction mechanism for the Ru/SiO{sub 2} system at 1000 deg. C is presented.

Wen, H.-C.; Lysaght, P.; Alshareef, H.N.; Huffman, C.; Harris, H.R.; Choi, K.; Senzaki, Y.; Luan, H.; Majhi, P.; Lee, B.H.; Campin, M. J.; Foran, B.; Lian, G.D.; Kwong, D.-L. [SEMATECH, 2706 Montopolis Drive, Austin, Texas 78741(United States); University of Texas at Austin, Pickle Research Campus-Microelectronics and Engineering Research (PRC-MER) Building 2.606A/R9950, Austin, Texas 78712 (United States); SEMATECH, 2706 Montopolis Drive, Austin, Texas 78741 (United States); Advanced Technology Development Facility (ATDF) Inc., 2706 Montopolis Drive, Austin, Texas 78741 (United States); University of Texas at Austin, Pickle Research Campus-Microelectronics and Engineering Research (PRC-MER) Building 2.606A/R9950, Austin, Texas 78712 (United States)

2005-08-15T23:59:59.000Z

464

Critical cooling rate and thermal stability of Zr--Ti--Cu--Ni--Be alloys  

SciTech Connect

The critical cooling rate as well as the thermal stability are measured for a series of alloys in the Zr--Ti--Cu--Ni--Be system. Upon cooling from the molten state with different rates, alloys with compositions ranging along a tie line from (Zr{sub 70}Ti{sub 30}){sub 55}(Ni{sub 39}Cu{sub 61}){sub 25}Be{sub 20} to (Zr{sub 85}Ti{sub 15}){sub 55}(Ni{sub 57}Cu{sub 43}){sub 22.5}Be{sub 27.5} show a continuous increase in the critical cooling rate to suppress crystallization. In contrast, thermal analysis of the same alloys shows that the undercooled liquid region, the temperature difference between the glass transition temperature and the crystallization temperature, is largest for some compositions midway between the two endpoints, revealing that glass forming ability does not correlate with thermal stability. The relationship between the composition-dependent glass forming ability and thermal stability is discussed with reference to a chemical decomposition process.

Waniuk, Theodore A.; Schroers, Jan; Johnson, William L.

2001-02-26T23:59:59.000Z

465

Investigations of the g{sub K}-factors in the {sup 175,177,179}Hf Isotopes  

SciTech Connect

In this paper the intrinsic g{sub K} and effective spin g{sub s} factors of the odd-mass {sup 175-179}Hf isotopes have been investigated within the Tamm-Dancoff approximation by using the realistic Saxon-Woods potential. The theoretically calculated g{sub K} and g{sub s}{sup eff} values are compared with experimental data. The comparison of the measured and calculated values of the effective g{sub s} factor shows that the spin polarization explains quite well the observed reduction of g{sub s} from its free-nucleon value.

Yakut, Hakan; Kuliev, Ali [Sakarya University, Department of physics, Sakarya (Turkey); Guliyev, Ekber [National Academy of Sciences, Institute of Physics, Baku (Azerbaijan)

2008-11-11T23:59:59.000Z

466

Transient phenomena in the dielectric breakdown of HfO{sub 2} optical films probed by ultrafast laser pulse pairs  

SciTech Connect

The laser induced breakdown threshold of HfO{sub 2} films is studied with single pairs of pulses of variable delay and 50 fs and 1 ps pulse duration. Two distinct transient regimes are observed that can be related to the relaxation of the electron density from the conduction band via an intermediate state to the valence band. The experimental results are in good agreement with a theoretical model that assumes occupation of mid gap states after the first pulse on a time scale of several tens of picoseconds and subsequent decay of this population via recombination with holes in the valence band on a time scale of several tens of milliseconds.

Nguyen, Duy N.; Emmert, Luke A.; Rudolph, Wolfgang [Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Patel, Dinesh; Menoni, Carmen S. [Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

2010-11-08T23:59:59.000Z

467

Controlled oxygen vacancy induced p-type conductivity in HfO{sub 2-x} thin films  

SciTech Connect

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.

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)

2011-09-12T23:59:59.000Z

468

Room temperature strain rate sensitivity in precursor derived HfO{sub 2}/Si-C-N(O) ceramic nanocomposites  

SciTech Connect

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.

Sujith, Ravindran; Kumar, Ravi, E-mail: nvrk@iitm.ac.in [Materials Processing Section, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai-600036, India. (India)] [Materials Processing Section, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai-600036, India. (India)

2014-01-15T23:59:59.000Z

469

Physical properties and band structure of reactive molecular beam epitaxy grown oxygen engineered HfO{sub 2{+-}x}  

SciTech Connect

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.

Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

2012-12-01T23:59:59.000Z

470

Energy band alignment of atomic layer deposited HfO{sub 2} on epitaxial (110)Ge grown by molecular beam epitaxy  

SciTech Connect

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.

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)

2013-03-04T23:59:59.000Z

471

Photo-induced tunneling currents in MOS structures with various HfO{sub 2}/SiO{sub 2} stacking dielectrics  

SciTech Connect

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.

Pang, Chin-Sheng; Hwu, Jenn-Gwo, E-mail: jghwu@ntu.edu.tw [Graduate Institute of Electronics Engineering/Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan (China)] [Graduate Institute of Electronics Engineering/Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan (China)

2014-04-15T23:59:59.000Z

472

Sliding force measurements on the LHC RF contact Plug In Modules at 15 K and in UHV  

E-Print Network (OSTI)

Some sliding RF contacts mounted in the Plug In Modules in the LHC interconnects failed during a thermal cycle between 4.2 K and room temperature. Gold-coated copperberyllium RF fingers buckled during the warm up of the machine, indicating that one or more parameters during operation (e.g. the friction coefficient under vacuum) could be different from what was used in the calculations. This report describes the measurement of the longitudinal forces acting on the sliding RF fingers at operating vacuum and temperatures.

Artoos, K; Renaglia, T

2008-01-01T23:59:59.000Z

473

Effect of ceria loading on the carbon formation during low temperature methane steam reforming over a Ni/CeO2/ZrO2 catalyst  

Science Journals Connector (OSTI)

The characterization and catalytic activity of a Ni/CeO2/ZrO2 catalyst for methane steam reforming at 600C were investigated. The addition...

Anton Purnomo; Susan Gallardo; Leonila Abella

2008-12-01T23:59:59.000Z

474

RE/ZrO{sub 2} (RE = Sm, Eu) composite oxide nano-materials: Synthesis and applications in photocatalysis  

SciTech Connect

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 solgel 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.

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)

2013-10-15T23:59:59.000Z

475

Neutron capture cross sections of /sup 178/,/sup 179/,/sup 180/Hf and the origin of nature's rarest stable isotope /sup 180/Ta  

SciTech Connect

The neutron capture cross sections of /sup 178/,/sup 179/,/sup 180/Hf were measured in the energy range 2.6 keV to 2 MeV. The average capture cross sections were derived and fitted in terms of strength functions. Resonance parameters for the observed resonances below 10 keV were determined by shape analysis. Maxwellian-averaged capture cross sections were computed for thermal energies with kT between 5 and 100 keV. The cross sections for kT = 30 keV were used to determine the population probability of the 8- isomeric level in /sup 180/Hf by neutron capture as (1.24 +- 0.06)% and the r-process abundance of /sup 180/Hf as 0.0290 (Si = 10/sup 6/). These quantities served to analyze s- and r-process nucleosynthesis of /sup 180/Ta, nature's rarest stable isotope.

Beer, H.; Macklin, R.L.

1982-01-01T23:59:59.000Z

476

Electrical characteristics and thermal stability of HfO{sub 2} metal-oxide-semiconductor capacitors fabricated on clean reconstructed GaSb surfaces  

SciTech Connect

HfO{sub 2}/GaSb interfaces fabricated by high-vacuum HfO{sub 2} deposition on clean reconstructed GaSb surfaces were examined to explore a thermally stable GaSb metal-oxide-semiconductor structure with low interface-state density (D{sub it}). Interface Sb-O bonds were electrically and thermally unstable, and post-metallization annealing at temperatures higher than 200?C was required to stabilize the HfO{sub 2}/GaSb interfaces. However, the annealing led to large D{sub it} in the upper-half band gap. We propose that the decomposition products that are associated with elemental Sb atoms act as interface states, since a clear correlation between the D{sub it} and the Sb coverage on the initial GaSb surfaces was observed.

Miyata, Noriyuki, E-mail: nori.miyata@aist.go.jp; Mori, Takahiro; Yasuda, Tetsuji [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Ohtake, Akihiro [National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan); Ichikawa, Masakazu [The University of Tokyo, Tokyo 113-8656 (Japan)

2014-06-09T23:59:59.000Z

477

Effect of nitrogen incorporation on improvement of leakage properties in high-k HfO{sub 2} capacitors treated by N{sub 2}-plasma  

SciTech Connect

The nitrogen incorporation into the HfO{sub 2} films with an EOT (equivalent oxide thickness) of 9 A was performed by N{sub 2}-plasma to improve the electrical properties. The dielectric properties and a leakage current characteristics of the capacitors were investigated as a function of plasma power and plasma treatment temperature. The dielectric constant of the capacitors is not influenced by nitrogen incorporation. The N{sub 2}-plasma treatment at 300 deg. C and 70 W exhibits the most effective influence on improvement of the leakage current characteristics. Leakage current density of the capacitors treated at 300 deg. C and 70 W exhibits a half order of magnitude lower than that without plasma treatment. Nitrogen incorporated into the HfO{sub 2} films possesses the intrinsic effect that drastically reduce the electron leakage current through HfO{sub 2} dielectrics by deactivating the V{sub O} (oxygen vacancy) related gap states.

Seong, Nak-Jin; Yoon, Soon-Gil; Yeom, Seung-Jin; Woo, Hyun-Kyung; Kil, Deok-Sin; Roh, Jae-Sung; Sohn, Hyun-Chul [Department of Materials Science and Engineering, Chungnam National University, Daeduk Science Town, 305-764, Daejon (Korea, Republic of); Hynix Semiconductor Inc., San 136-1 Ami-ri Bubal-eub Icheon-si Kyoungki-do, 467-701 (Korea, Republic of)

2005-09-26T23:59:59.000Z

478

Demonstrating 1 nm-oxide-equivalent-thickness HfO{sub 2}/InSb structure with unpinning Fermi level and low gate leakage current density  

SciTech Connect

In this work, the band alignment, interface, and electrical characteristics of HfO{sub 2}/InSb metal-oxide-semiconductor structure have been investigated. By using x-ray photoelectron spectroscopy analysis, the conduction band offset of 1.78 0.1 eV and valence band offset of 3.35 0.1 eV have been extracted. The transmission electron microscopy analysis has shown that HfO{sub 2} layer would be a good diffusion barrier for InSb. As a result, 1 nm equivalent-oxide-thickness in the 4 nm HfO{sub 2}/InSb structure has been demonstrated with unpinning Fermi level and low leakage current of 10{sup ?4} A/cm{sup ?2}. The D{sub it} value of smaller than 10{sup 12} eV{sup ?1}cm{sup ?2} has been obtained using conduction method.

Trinh, Hai-Dang [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China) [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Lin, Yueh-Chin; Nguyen, Hong-Quan; Luc, Quang-Ho [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China)] [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Nguyen, Minh-Thuy; Duong, Quoc-Van; Nguyen, Manh-Nghia [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam)] [Department of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Wang, Shin-Yuan [Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China)] [Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China); Yi Chang, Edward [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China) [Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan (China); Department of Electronic Engineering, National Chiao Tung University 1001, University Rd., Hsinchu 300, Taiwan (China)

2013-09-30T23:59:59.000Z

479

Band alignment and interfacial structure of ZnO/Si heterojunction with Al{sub 2}O{sub 3} and HfO{sub 2} as interlayers  

SciTech Connect

Energy band alignment of ZnO/Si heterojunction with thin interlayers Al{sub 2}O{sub 3} and HfO{sub 2} grown by atomic layer deposition has been studied using x-ray photoelectron spectroscopy. The valence band offsets of ZnO/Al{sub 2}O{sub 3} and ZnO/HfO{sub 2} heterojunctions have been determined to be 0.43 and 0.22?eV, respectively. Accordingly, the band alignment ZnO/Si heterojunction is then modified to be 0.34 and 0.50?eV through inserting a thin Al{sub 2}O{sub 3} and HfO{sub 2} layer, respectively. The feasibility to tune the band structure of ZnO/Si heterojunction by selecting a proper interlayer shows great advantage in improving the performance of the ZnO-based optoelectronic devices.

Lu, Hong-Liang, E-mail: honglianglu@fudan.edu.cn; Yang, Ming; Xie, Zhang-Yi; Geng, Yang; Zhang, Yuan; Wang, Peng-Fei; Sun, Qing-Qing; Ding, Shi-Jin; Wei Zhang, David [State Key Laboratory of ASIC and System, Institute of Advanced Nanodevices, School of Microelectronics, Fudan University, Shanghai 200433 (China)

2014-04-21T23:59:59.000Z

480

Thickness-modulated optical dielectric constants and band alignments of HfO{sub x}N{sub y} gate dielectrics  

SciTech Connect

Thickness-modulated optical dielectric constants and band alignments of HfO{sub x}N{sub y} films grown by sputtering have been investigated by spectroscopic ellipsometry (SE) and x-ray photoelectron spectroscopy. Based on SE measurements, it has been noted that an increase in optical dielectric constant and band gap has been observed as a function of the film thickness. Analyses of thickness-dependent band alignment of the HfO{sub x}N{sub y}/Si system indicate that the valence band offset increases, but only slight change in the conduction band offset, resulting from the thickness-induced change in the structure. The suitable optical dielectric constants and band offsets relative to Si make sputtering-derived HfO{sub x}N{sub y} film a promising candidate for high-k gate dielectrics.

He, G.; Zhang, L. D.; Liu, M.; Zhang, J. P.; Wang, X. J. [Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhen, C. M. [Department of Physics, Hebei Advanced Thin Films Laboratory, Hebei Normal University, Shijiazhuang 050016 (China)

2009-01-01T23:59:59.000Z