The rf-power dependences of the deposition rate, the hardness and the corrosion-resistance of the chromium nitride film deposited by using a dual ion beam sputtering system

International Nuclear Information System (INIS)

Lim, Jongmin; Lee, Chongmu

2006-01-01

The hexavalent chromium used in chromium plating is so toxic that it is very hazardous to human body and possibly causes cancer in humans. Therefore, it is indispensable to develop an alternative deposition technique. Dependences of the deposition rate, the phases, the hardness, the surface roughness and the corrosion-resistance of CrN x deposited on the high speed steel substrate by using a dual ion beam sputtering system on the rf-power were investigated to see the feasibility of sputtering as an alternative technique for chromium plating. The dual ion beam sputtering system used in this study was designed in such a way as the primary argon ion beam and the secondary nitrogen ion beam are injected toward the target and the substrate, respectively so that the chromium atoms at the chromium target surface may not nearly react with nitrogen atoms. The hardness and the surface roughness were measured by a micro-Vicker's hardness tester and an atomic force microscope (AFM), respectively. X-ray diffraction analyses were performed to identify phases in the films. The deposition rate of CrN x depends more strongly upon the rf-power for argon ion beam than that for nitrogen ion beam. The hardness of the CrN x film is highest when the volume percent of the Cr 2 N phase in the film is highest. Amorphous films are obtained when the rf-power for nitrogen ion beam is much higher than that for argon ion beam. The CrN x film deposited by using the sputtering technique under the optimal condition provides corrosion-resistance comparable to that of the electroplated chromium

An optimized nanoparticle separator enabled by electron beam induced deposition

International Nuclear Information System (INIS)

Fowlkes, J D; Rack, P D; Doktycz, M J

2010-01-01

Size-based separations technologies will inevitably benefit from advances in nanotechnology. Direct-write nanofabrication provides a useful mechanism for depositing/etching nanoscale elements in environments otherwise inaccessible to conventional nanofabrication techniques. Here, electron beam induced deposition was used to deposit an array of nanoscale features in a 3D environment with minimal material proximity effects outside the beam-interaction region. Specifically, the membrane component of a nanoparticle separator was fabricated by depositing a linear array of sharply tipped nanopillars, with a singular pitch, designed for sub-50 nm nanoparticle permeability. The nanopillar membrane was used in a dual capacity to control the flow of nanoparticles in the transaxial direction of the array while facilitating the sealing of the cellular-sized compartment in the paraxial direction. An optimized growth recipe resulted which (1) maximized the growth efficiency of the membrane (which minimizes proximity effects) and (2) preserved the fidelity of the spacing between nanopillars (which maximizes the size-based gating quality of the membrane) while (3) maintaining sharp nanopillar apexes for impaling an optically transparent polymeric lid critical for device sealing.

An optimized nanoparticle separator enabled by electron beam induced deposition

Science.gov (United States)

Fowlkes, J. D.; Doktycz, M. J.; Rack, P. D.

2010-04-01

Size-based separations technologies will inevitably benefit from advances in nanotechnology. Direct-write nanofabrication provides a useful mechanism for depositing/etching nanoscale elements in environments otherwise inaccessible to conventional nanofabrication techniques. Here, electron beam induced deposition was used to deposit an array of nanoscale features in a 3D environment with minimal material proximity effects outside the beam-interaction region. Specifically, the membrane component of a nanoparticle separator was fabricated by depositing a linear array of sharply tipped nanopillars, with a singular pitch, designed for sub-50 nm nanoparticle permeability. The nanopillar membrane was used in a dual capacity to control the flow of nanoparticles in the transaxial direction of the array while facilitating the sealing of the cellular-sized compartment in the paraxial direction. An optimized growth recipe resulted which (1) maximized the growth efficiency of the membrane (which minimizes proximity effects) and (2) preserved the fidelity of the spacing between nanopillars (which maximizes the size-based gating quality of the membrane) while (3) maintaining sharp nanopillar apexes for impaling an optically transparent polymeric lid critical for device sealing.

Ion beam and dual ion beam sputter deposition of tantalum oxide films

Science.gov (United States)

Cevro, Mirza; Carter, George

1994-11-01

Ion beam sputter deposition (IBS) and dual ion beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. Optical properties ie refractive index and extinction coefficient of IBS films were determined in the 250 - 1100 nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n equals 2.06 at (lambda) equals 550 nm. Films deposited using DIBS ie deposition assisted by low energy Ar and O2 ions (Ea equals 0 - 300 eV) and low current density (Ji equals 0 - 40 (mu) A/cm2) showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy while composition of the film and contaminants were determined by Rutherford scattering spectroscopy. Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target while assisted deposition slightly increased the Ar content. Stress in the IBS deposited films was measured by the bending technique. IBS deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals 35 (mu) A/cm2. All

Ion-beam and dual-ion-beam sputter deposition of tantalum oxide films

Science.gov (United States)

Cevro, Mirza; Carter, George

1995-02-01

Ion-beam sputter deposition (IBS) and dual-ion-beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. The optical properties, i.e., refractive index and extinction coefficient, of IBS films were determined in the 250- to 1100-nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n 2.06 at (lambda) equals 550 nm. Films deposited using DIBS, i.e., deposition assisted by low energy Ar and O2 ions (Ea equals 0 to 300 eV) and low current density (Ji equals 0 to 40 (mu) A/cm2), showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy, whereas composition of the film and contaminants were determined by Rutherford backscattering spectroscopy (RBS). Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target whereas assisted deposition slightly increased the Ar content. Stress in the IBS-deposited films was measured by the bending technique. IBS-deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals

Low current beam techniques

Energy Technology Data Exchange (ETDEWEB)

Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

1993-12-31

Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

Low current beam techniques

Energy Technology Data Exchange (ETDEWEB)

Saint, A; Laird, J S; Bardos, R A; Legge, G J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T; Sekiguchi, H [Electrotechnical Laboratory, Tsukuba (Japan).

1994-12-31

Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

Real-time beam tracing for control of the deposition location of electron cyclotron waves

Energy Technology Data Exchange (ETDEWEB)

Reich, M., E-mail: matthias.reich@ipp.mpg.de; Bilato, R.; Mszanowski, U.; Poli, E.; Rapson, C.; Stober, J.; Volpe, F.; Zille, R.

2015-11-15

Highlights: • We successfully integrated a real-time EC beam tracing code at ASDEX Upgrade. • The calculation of EC beam deposition location is fast enough for control purposes. • The accuracy of the deposition location calculation exceeds equivalent measurements. • The implementation method is by design portable to larger fusion devices. - Abstract: Plasma control techniques that use electron cyclotron (EC) resonance heating and current drive such as control of neoclassical tearing modes require accurate control of the deposition location of EC beams. ASDEX Upgrade has successfully implemented a real-time version of the beam-tracing code TORBEAM into its real-time diagnostic system to act as a globally available module that calculates current deposition location and its sensitivity from other real-time diagnostic measurements for all its moveable EC wave launchers. Based on a highly (100×) accelerated version of TORBEAM, the software implementation as a diagnostic process uses parallelization and achieves cycle times of 15–20 ms for determining the radial deposition location of 12 beams in the plasma. This cycle time includes data input–output overhead arising from the use of available real-time signals. The system is by design portable to other machines such as ITER.

Superhydrophobic polytetrafluoroethylene thin films with hierarchical roughness deposited using a single step vapor phase technique

International Nuclear Information System (INIS)

Gupta, Sushant; Arjunan, Arul Chakkaravarthi; Deshpande, Sameer; Seal, Sudipta; Singh, Deepika; Singh, Rajiv K.

2009-01-01

Superhydrophobic polytetrafluoroethylene films with hierarchical surface roughness were deposited using pulse electron deposition technique. We were able to modulate roughness of the deposited films by controlling the beam energy and hence the electron penetration depth. The films deposited at higher beam energy showed contact angle as high as 166 o . The scanning electron and atomic force microscope studies revealed clustered growth and two level sub-micron asperities on films deposited at higher energies. Such dual-scale hierarchical roughness and heterogeneities at the water-surface interface was attributed to the observed contact angle and thus its superhydrophobic nature.

Superhydrophobic polytetrafluoroethylene thin films with hierarchical roughness deposited using a single step vapor phase technique

Energy Technology Data Exchange (ETDEWEB)

Gupta, Sushant, E-mail: sushant3@ufl.ed [Department of Materials Science and Engineering, University of Florida, Gainesville, FL 32611 (United States); Arjunan, Arul Chakkaravarthi [Sinmat Incorporated, 2153 SE Hawthorne Road, 129, Gainesville, Florida 32641 (United States); Deshpande, Sameer; Seal, Sudipta [Advanced Material Processing and Analysis Center, University of Central Florida, Orlando, Florida 32816 (United States); Singh, Deepika [Sinmat Incorporated, 2153 SE Hawthorne Road, 129, Gainesville, Florida 32641 (United States); Singh, Rajiv K. [Department of Materials Science and Engineering, University of Florida, Gainesville, FL 32611 (United States)

2009-06-30

Superhydrophobic polytetrafluoroethylene films with hierarchical surface roughness were deposited using pulse electron deposition technique. We were able to modulate roughness of the deposited films by controlling the beam energy and hence the electron penetration depth. The films deposited at higher beam energy showed contact angle as high as 166{sup o}. The scanning electron and atomic force microscope studies revealed clustered growth and two level sub-micron asperities on films deposited at higher energies. Such dual-scale hierarchical roughness and heterogeneities at the water-surface interface was attributed to the observed contact angle and thus its superhydrophobic nature.

Study of Sb/SnO{sub 2} bi-layer films prepared by ion beam sputtering deposition technique

Energy Technology Data Exchange (ETDEWEB)

Wang, Chun-Min [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC (China); Huang, Chun-Chieh [Department of Electrical Engineering, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Township, Kaohsiung 833, Taiwan, ROC (China); Kuo, Jui-Chao [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC (China); Huang, Jow-Lay, E-mail: jlh888@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC (China); Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan, ROC (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan, ROC (China)

2014-11-03

In the present work, bi-layer thin films of Sb/SnO{sub 2} were produced on unheated glass substrates using ion beam sputtering (IBS) technique without post annealing treatment. The thickness of Sb layers was varied from 2 to 10 nm and the Sb layers were deposited on SnO{sub 2} layers having thicknesses of 40 nm to 115 nm. The effect of thickness was studied on the morphological, electrical and optical properties. The Sb/SnO{sub 2} bi-layer resulted in lowering the electrical resistivity as well as reducing the optical transmittance. However, the optical and electrical properties of the bi-layer films were mainly influenced by the thickness of Sb layers due to progressive transfer in structures from aggregate to continuous films. The bi-layer films show the electrical resistivity of 1.4 × 10{sup −3} Ω cm and an optical transmittance of 26% for Sb film having 10 nm thickness. - Highlights: • Bi-layer Sb/SnO{sub 2} structures were synthesized by ion beam sputtering (IBS) technique. • The 6 nm-thick Sb film is a transition region in this study. • The conductivity of the bi-layer films is increased as Sb thickness increases. • The transmittance of the bi-layer films is decreased as Sb thickness increases.

Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

International Nuclear Information System (INIS)

Aronne, Antonio; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Depero, Laura E.; Fanelli, Esther; Federici, Stefania; Massoli, Patrizio; Vicari, Luciano R.M.

2015-01-01

Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence

Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

Energy Technology Data Exchange (ETDEWEB)

Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Bloisi, Francesco, E-mail: bloisi@na.infn.it [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy); Calabria, Raffaela; Califano, Valeria [Istituto Motori – CNR, Naples (Italy); Depero, Laura E. [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Federici, Stefania [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Massoli, Patrizio [Istituto Motori – CNR, Naples (Italy); Vicari, Luciano R.M. [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy)

2015-05-01

Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence.

Local deposition of high-purity Pt nanostructures by combining electron beam induced deposition and atomic layer deposition

NARCIS (Netherlands)

Mackus, A.J.M.; Mulders, J.J.L.; Sanden, van de M.C.M.; Kessels, W.M.M.

2010-01-01

An approach for direct-write fabrication of high-purity platinum nanostructures has been developed by combining nanoscale lateral patterning by electron beam induced deposition (EBID) with area-selective deposition of high quality material by atomic layer deposition (ALD). Because virtually pure,

Investigation of morphological changes in platinum-containing nanostructures created by electron-beam-induced deposition

NARCIS (Netherlands)

Botman, A.; Hesselberth, M.; Mulders, J.J.L.

2008-01-01

Focused electron-beam-induced deposition (EBID) allows the rapid fabrication of three-dimensional nanodevices and metallic wiring of nanostructures, and is a promising technique for many applications in nanoresearch. The authors present two topics on platinum-containing nanostructures created by

Deposition of thin films by retardation of an isotope separator beam

International Nuclear Information System (INIS)

Colligon, J.S.; Grant, W.A.; Williams, J.S.; Lawson, R.P.W.

1976-01-01

An ion optical lens system capable of retarding and focusing a mass-analysed ion beam, produced in the University of Salford isotope separator, from an energy of 20 keV to 50-60 eV is described. Using this system it is technically feasible to deposit spectroscopically pure ions of all species onto a substrate to produce thin film for devices and junctions. Preliminary investigations of the technique have been carried out using lead and copper ions which were deposited onto silicon single-crystal substrates. These ions were selected because their high mass relative to silicon allowed analyses of the deposited films by low-angle Rutherford backscattering of 2 MeV He ions; the single-crystal silicon substrate enabled the extent of damage due to unretarded neutral particles to be estimated from channelling data. Results for lead films showed that films less than 150 A in thickness were discontinuous and scanning electron microscopy confirmed their 'island' structure. For thicker deposits, of order 600 A, the films were continuous. Results are also presented for copper-lead sandwich layers produced by successive depositions. Channelling experiments indicated that the neutral component was less than 5% of the total ion-beam intensity. Investigations of the spatial distribution of the lead films indicated a non-uniformity which, it is suggested, arises from a fault in the retardation lens design. (author)

Computer simulation of scattered ion and sputtered species effects in ion beam sputter-deposition of high temperature superconducting thin films

International Nuclear Information System (INIS)

Krauss, A.R.; Auciello, O.

1992-01-01

Ion beam sputter-deposition is a technique currently used by many groups to produce single and multicomponent thin films. This technique provides several advantages over other deposition methods, which include the capability for yielding higher film density, accurate stoichiometry control, and smooth surfaces. However, the relatively high kinetic energies associated with ion beam sputtering also lead to difficulties if the process is not properly controlled. Computer simulations have been performed to determine net deposition rates, as well as the secondary erosion, lattice damage, and gas implantation in the films, associated with primary ions scattered from elemental Y, Ba and Cu targets used to produce high temperature superconducting Y-Ba-Cu-O films. The simulations were performed using the TRIM code for different ion masses and kinetic energies, and different deposition geometries. Results are presented for primary beams of Ar + , Kr + and Xe + incident on Ba and Cu targets at 0 degrees and 45 degrees with respect to the surface normal, with the substrate positioned at 0 degrees and 45 degrees. The calculations indicate that the target composition, mass and kinetic energy of the primary beam, angle of incidence on the target, and position and orientation of the substrate affect the film damage and trapped primary beam gas by up to 5 orders of magnitude

Ion beam techniques for analyzing polymers irradiated by ions

International Nuclear Information System (INIS)

Rickards, J.; Zironi, E.P.; Andrade, E.; Dominguez, B.

1992-01-01

In the study of the effects of ion beam irradiation of polymers very large doses can be administered in short times. Thousands of MGy can be produced in a small volume of a sample in a few minutes by bombarding with typical ion beam currents. For instance, in an experiment done to observe the effects of 750 keV proton irradiation PVC, using a collimator of 1 mm diameter, 1 μC of charge integration deposits a dose of 50 MGy. The use of ion beams also opens up the possibility of using the same beam for irradiation and for analysis of the effects, using the well known ion beam analysis techniques. PIXE allows the measurement of chlorine in PVC. Polymers containing fluorine can be measured with the resonant nuclear reaction (RNR) technique, which is specific only to certain elements. The amount of hydrogen in the sample and its profile can be obtained using energy recoil detection analysis (ERDA); carbon, oxygen, and nitrogen can be measured and profiled using Rutherford backscattering (RBS) and also using the (d,p) and (d, α) nuclear reactions (NR). Loss of mass is one effect that can be studied using these techniques. It was studied in two different polymers, PVC and CR-39, in order to determine carbon buildup during ion irradiation. It was concluded that carbon builds up following different mechanisms in these two materials, due to the different possibilities of forming volatile compounds. It is also suggested that CR-39 should be a good material for ion beam lithography. (author)

Techniques for the research on mass deposition effects in the bio-materials induced by heavy ion implantation

International Nuclear Information System (INIS)

Yuan Shibin; Wei Zengquan; Li Qiang

2002-01-01

Researchers have used heavy ion beams to implant small biomolecules, followed by advanced instrumental analysis to make preliminary studies on mass deposition induced by ion implantation. But research reports on the biological effects, i.e. mass deposition effects induced by mass deposition in living tissues, cells and macro-biomolecules have not been delivered hitherto. In the near future radioactive heavy ion beams will be possible to implant living cells and biomolecules, and auto-radiography, radioactive measurements and molecular biological techniques will be employed to further studies on the effects

The rational design of a Au(I) precursor for focused electron beam induced deposition

NARCIS (Netherlands)

Marashdeh, Ali; Tiesma, Thiadrik; van Velzen, Niels J. C.; Harder, Sjoerd; Havenith, Remco W. A.; De Hosson, Jeff T. M.; van Dorp, Willem F.

2017-01-01

Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition.

Beam Techniques - Beam Control and Manipulation

International Nuclear Information System (INIS)

Minty, Michiko G

2003-01-01

We describe commonly used strategies for the control of charged particle beams and the manipulation of their properties. Emphasis is placed on relativistic beams in linear accelerators and storage rings. After a brief review of linear optics, we discuss basic and advanced beam control techniques, such as transverse and longitudinal lattice diagnostics, matching, orbit correction and steering, beam-based alignment, and linac emittance preservation. A variety of methods for the manipulation of particle beam properties are also presented, for instance, bunch length and energy compression, bunch rotation, changes to the damping partition number, and beam collimation. The different procedures are illustrated by examples from various accelerators. Special topics include injection and extraction methods, beam cooling, spin transport and polarization

Beam Techniques - Beam Control and Manipulation

Energy Technology Data Exchange (ETDEWEB)

Minty, Michiko G

2003-04-24

We describe commonly used strategies for the control of charged particle beams and the manipulation of their properties. Emphasis is placed on relativistic beams in linear accelerators and storage rings. After a brief review of linear optics, we discuss basic and advanced beam control techniques, such as transverse and longitudinal lattice diagnostics, matching, orbit correction and steering, beam-based alignment, and linac emittance preservation. A variety of methods for the manipulation of particle beam properties are also presented, for instance, bunch length and energy compression, bunch rotation, changes to the damping partition number, and beam collimation. The different procedures are illustrated by examples from various accelerators. Special topics include injection and extraction methods, beam cooling, spin transport and polarization.

A critical literature review of focused electron beam induced deposition

International Nuclear Information System (INIS)

Dorp, W. F. van; Hagen, C. W.

2008-01-01

, there is a limited understanding of the mechanism of electron induced precursor dissociation. In many cases, the deposit composition is not directly dependent on the stoichiometric composition of the precursor and the electron induced decomposition paths can be very different from those expected from calculations or thermal decomposition. The dissociation mechanism is one of the key factors determining the purity of the deposits and a better understanding of this process will help develop electron beam induced deposition into a viable nanofabrication technique

Enhancement of the optical and electrical properties of ITO thin films deposited by electron beam evaporation technique

Science.gov (United States)

Ali, H. M.; Mohamed, H. A.; Mohamed, S. H.

2005-08-01

Indium tin oxide (ITO) is widely utilized in numerous industrial applications due to its unique combined properties of transparency to visible light and electrical conductivity. ITO films were deposited on glass substrates by an electron beam evaporation technique at room temperature from bulk samples, with different thicknesses. The film with 1500 Å thick was selected to perform annealing in the temperature range of 200 400 °C and annealing for varying times from 15 to 120 min at 400 °C. The X-ray diffraction of the films was analyzed in order to investigate its dependence on thickness, and annealing. Electrical and optical measurements were also carried out. Transmittance, optical energy gap, refractive index, carrier concentration, thermal emissivity and resistivity were investigated. It was found that the as-deposited films with different thicknesses were highly absorbing and have relatively poor electrical properties. The films become opaque with increasing the film thickness. After thermal annealing, the resistance decreases and a simultaneous variation in the optical transmission occurs. A transmittance value of 85.5% in the IR region and 82% in the visible region of the spectrum and a resistivity of 2.8 × 10-4 Ω Cm were obtained at annealing temperature of 400 °C for 120 min.

Handbook of thin film deposition processes and techniques principles, methods, equipment and applications

CERN Document Server

Seshan, Krishna

2002-01-01

New second edition of the popular book on deposition (first edition by Klaus Schruegraf) for engineers, technicians, and plant personnel in the semiconductor and related industries. This book traces the technology behind the spectacular growth in the silicon semiconductor industry and the continued trend in miniaturization over the last 20 years. This growth has been fueled in large part by improved thin film deposition techniques and the development of highly specialized equipment to enable this deposition. The book includes much cutting-edge material. Entirely new chapters on contamination and contamination control describe the basics and the issues-as feature sizes shrink to sub-micron dimensions, cleanliness and particle elimination has to keep pace. A new chapter on metrology explains the growth of sophisticated, automatic tools capable of measuring thickness and spacing of sub-micron dimensions. The book also covers PVD, laser and e-beam assisted deposition, MBE, and ion beam methods to bring together a...

Calculation of neutral beam deposition accounting for excited states

International Nuclear Information System (INIS)

Gianakon, T.A.

1992-09-01

Large-scale neutral-beam auxillary heating of plasmas has led to new plasma operational regimes which are often dominated by fast ions injected via the absorption of an energetic beam of hydrogen neutrals. An accurate simulation of the slowing down and transport of these fast ions requires an intimate knowledge of the hydrogenic neutral deposition on each flux surface of the plasma. As a refinement to the present generation of transport codes, which base their beam deposition on ground-state reaction rates, a new set of routines, based on the excited states of hydrogen, is presented as mechanism for computing the attenuation and deposition of a beam of energetic neutrals. Additionally, the numerical formulations for the underlying atomic physics for hydrogen impacting on the constiuent plasma species is developed and compiled as a numerical database. Sample results based on this excited state model are compared with the ground-state model for simple plasma configurations

Second order nonlinear optical properties of zinc oxide films deposited by low temperature dual ion beam sputtering

International Nuclear Information System (INIS)

Larciprete, M.C.; Passeri, D.; Michelotti, F.; Paoloni, S.; Sibilia, C.; Bertolotti, M.; Belardini, A.; Sarto, F.; Somma, F.; Lo Mastro, S.

2005-01-01

We investigated second order optical nonlinearity of zinc oxide thin films, grown on glass substrates by the dual ion beam sputtering technique under different deposition conditions. Linear optical characterization of the films was carried out by spectrophotometric optical transmittance and reflectance measurements, giving the complex refractive index dispersion. Resistivity of the films was determined using the four-point probe sheet resistance method. Second harmonic generation measurements were performed by means of the Maker fringes technique where the fundamental beam was originated by nanosecond laser at λ=1064 nm. We found a relatively high nonlinear optical response, and evidence of a dependence of the nonlinear coefficient on the deposition parameters for each sample. Moreover, the crystalline properties of the films were investigated by x-ray diffraction measurements and correlation with second order nonlinearity were analyzed. Finally, we investigated the influence of the oxygen flow rate during the deposition process on both the second order nonlinearity and the structural properties of the samples

Nanosecond and femtosecond mass spectroscopic analysis of a molecular beam produced by the spray-jet technique

International Nuclear Information System (INIS)

Yamada, Toshiki; Shinohara, Hidenori; Kamikado, Toshiya; Okuno, Yoshishige; Suzuki, Hitoshi; Mashiko, Shinro; Yokoyama, Shiyoshi

2008-01-01

The spray-jet molecular beam apparatus enabled us to produce a molecular beam of non-volatile molecules under high vacuum from a sprayed mist of sample solutions. The apparatus has been used in spectroscopic studies and as a means of molecular beam deposition. We analyzed the molecular beam, consisting of non-volatile, solvent, and carrier-gas molecules, by using femtosecond- and nanosecond- laser mass spectroscopy. The information thus obtained provided insight into the molecular beam produced by the spray-jet technique

Current transport and capacitance-voltage characteristics of an n-PbTe/p-GaP heterojunction prepared using the electron beam deposition technique

Science.gov (United States)

Nasr, Mahmoud; El Radaf, I. M.; Mansour, A. M.

2018-04-01

In this study, a crystalline n-PbTe/p-GaP heterojunction was fabricated using the electron beam deposition technique. The structural properties of the prepared heterojunction were examined by X-ray diffraction and scanning electron microscopy. The dark current-voltage characteristics of the heterojunction were investigated at different temperatures ranging from 298 to 398 K. The rectification factor, series resistance, shunt resistance, diode ideality factor, and effective barrier height (ϕb) were determined. The photovoltaic parameters were identified based on the current density-voltage characteristics under illumination. The capacitance-voltage characteristics showed that the junction was abrupt in nature.

Advanced electron beam techniques

International Nuclear Information System (INIS)

Hirotsu, Yoshihiko; Yoshida, Yoichi

2007-01-01

After 100 years from the time of discovery of electron, we now have many applications of electron beam in science and technology. In this report, we review two important applications of electron beam: electron microscopy and pulsed-electron beam. Advanced electron microscopy techniques to investigate atomic and electronic structures, and pulsed-electron beam for investigating time-resolved structural change are described. (author)

Development of ion beam sputtering techniques for actinide target preparation

International Nuclear Information System (INIS)

Aaron, W.S.; Zevenbergen, L.A.; Adair, H.L.

1985-01-01

Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed. (orig.)

Development of ion beam sputtering techniques for actinide target preparation

Science.gov (United States)

Aaron, W. S.; Zevenbergen, L. A.; Adair, H. L.

1985-06-01

Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of a minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity actinides in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed.

Ion beams as a means of deposition and in-situ characterization of thin films and thin film layered structures

International Nuclear Information System (INIS)

Krauss, A.R.; Rangaswamy, M.; Gruen, D.M.; Lin, Y.P.; Schmidt, H.; Liu, Y.L.; Barr, T.; Chang, R.P.H.

1992-01-01

Ion beam-surface interactions produce many effects in thin film deposition which are similar to those encountered in plasma deposition processes. However, because of the lower pressures and higher directionality associated with the ion beam process, it is easier to avoid some sources of film contamination and to provide better control of ion energies and fluxes. Additional effects occur in the ion beam process because of the relatively small degree of thermalization resulting from gas phase collisions with both the ion beam and atoms sputtered from the target. These effects may be either beneficial or detrimental to the film properties, depending on the material and deposition conditions. Ion beam deposition is particularly suited to the deposition of multi-component films and layered structures, and can in principle be extended to a complete device fabrication process. However, complex phenomena occur in the deposition of many materials of high technical interest which make it desirable to monitor the film growth at the monolayer level. It is possible to make use of ion-surface interactions to provide a full suite of surface analytical capabilities in one instrument, and this data may be obtained at ambient pressures which are far too high for conventional surface analysis techniques. Such an instrument is under development and its current performance characteristics and anticipated capabilities are described

Effect of Different Catalyst Deposition Technique on Aligned Multiwalled Carbon Nanotubes Grown by Thermal Chemical Vapor Deposition

Directory of Open Access Journals (Sweden)

Mohamed Shuaib Mohamed Saheed

2014-01-01

Full Text Available The paper reported the investigation of the substrate preparation technique involving deposition of iron catalyst by electron beam evaporation and ferrocene vaporization in order to produce vertically aligned multiwalled carbon nanotubes array needed for fabrication of tailored devices. Prior to the growth at 700°C in ethylene, silicon dioxide coated silicon substrate was prepared by depositing alumina followed by iron using two different methods as described earlier. Characterization analysis revealed that aligned multiwalled carbon nanotubes array of 107.9 µm thickness grown by thermal chemical vapor deposition technique can only be achieved for the sample with iron deposited using ferrocene vaporization. The thick layer of partially oxidized iron film can prevent the deactivation of catalyst and thus is able to sustain the growth. It also increases the rate of permeation of the hydrocarbon gas into the catalyst particles and prevents agglomeration at the growth temperature. Combination of alumina-iron layer provides an efficient growth of high density multiwalled carbon nanotubes array with the steady growth rate of 3.6 µm per minute for the first 12 minutes and dropped by half after 40 minutes. Thicker and uniform iron catalyst film obtained from ferrocene vaporization is attributed to the multidirectional deposition of particles in the gaseous form.

Improved Understanding of Implosion Symmetry through New Experimental Techniques Connecting Hohlraum Dynamics with Laser Beam Deposition

Science.gov (United States)

Ralph, Joseph; Salmonson, Jay; Dewald, Eduard; Bachmann, Benjamin; Edwards, John; Graziani, Frank; Hurricane, Omar; Landen, Otto; Ma, Tammy; Masse, Laurent; MacLaren, Stephen; Meezan, Nathan; Moody, John; Parrilla, Nicholas; Pino, Jesse; Sacks, Ryan; Tipton, Robert

2017-10-01

Understanding what affects implosion symmetry has been a challenge for scientists designing indirect drive inertial confinement fusion experiments on the National Ignition Facility (NIF). New experimental techniques and data analysis have been employed aimed at improving our understanding of the relationship between hohlraum dynamics and implosion symmetry. Thin wall imaging data allows for time-resolved imaging of 10 keV Au l-band x-rays providing for the first time on the NIF, a spatially resolved measurement of laser deposition with time. In the work described here, we combine measurements from the thin wall imaging with time resolved views of the interior of the hohlraum. The measurements presented are compared to hydrodynamic simulations as well as simplified physics models. The goal of this work is to form a physical picture that better explains the relationship of the hohlraum dynamics and capsule ablator on laser beam propagation and implosion symmetry. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

Comparison of beam deposition for three neutral beam injection codes

International Nuclear Information System (INIS)

Wieland, R.M.; Houlberg, W.A.; Mense, A.T.

1979-03-01

The three neutral beam injection codes BEAM (Houlberg, ORNL), HOFR (Howe, ORNL), and FREYA (Post, PPPL) are compared with respect to the calculation of the fast ion deposition profile H(r). Only plasmas of circular cross section are considered, with injection confined to the mid-plane of the torus. The approximations inherent in each code are pointed out, and a series of comparisons varying several parameters (beam energy and radius, machine size, and injection angle) shows excellent agreement among all the codes. A cost comparison (execution time and memory requirements) is made which points out the relative merits of each code within the context of incorporation into a plasma transport simulation code

Spray deposition using impulse atomization technique

International Nuclear Information System (INIS)

Ellendt, N.; Schmidt, R.; Knabe, J.; Henein, H.; Uhlenwinkel, V.

2004-01-01

A novel technique, impulse atomization, has been used for spray deposition. This single fluid atomization technique leads to different spray characteristics and impact conditions of the droplets compared to gas atomization technique which is the common technique used for spray deposition. Deposition experiments with a Cu-6Sn alloy were conducted to evaluate the appropriateness of impulse atomization to produce dense material. Based on these experiments, a model has been developed to simulate the thermal history and the local solidification rates of the deposited material. A numerical study shows how different cooling conditions affect the solidification rate of the material

Imprint reduction in rotating heavy ions beam energy deposition

Energy Technology Data Exchange (ETDEWEB)

Bret, A., E-mail: antoineclaude.bret@uclm.es [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambridge, MA 02138 (United States); ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Piriz, A.R., E-mail: Roberto.Piriz@uclm.es [ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Tahir, N.A., E-mail: n.tahir@gsi.de [GSI Darmstadt, Plankstrasse 1, 64291 Darmstadt (Germany)

2014-01-01

The compression of a cylindrical target by a rotating heavy ions beam is contemplated in certain inertial fusion schemes or in heavy density matter experiments. Because the beam has its proper temporal profile, the energy deposition is asymmetric and leaves an imprint which can have important consequences for the rest of the process. In this paper, the Fourier components of the deposited ion density are computed exactly in terms of the beam temporal profile and its rotation frequency Ω. We show that for any beam profile of duration T, there exist an infinite number of values of ΩT canceling exactly any given harmonic. For the particular case of a parabolic profile, we find possible to cancel exactly the first harmonic and nearly cancel every other odd harmonics. In such case, the imprint amplitude is divided by 4 without any increase of Ω.

Imprint reduction in rotating heavy ions beam energy deposition

International Nuclear Information System (INIS)

Bret, A.; Piriz, A.R.; Tahir, N.A.

2014-01-01

The compression of a cylindrical target by a rotating heavy ions beam is contemplated in certain inertial fusion schemes or in heavy density matter experiments. Because the beam has its proper temporal profile, the energy deposition is asymmetric and leaves an imprint which can have important consequences for the rest of the process. In this paper, the Fourier components of the deposited ion density are computed exactly in terms of the beam temporal profile and its rotation frequency Ω. We show that for any beam profile of duration T, there exist an infinite number of values of ΩT canceling exactly any given harmonic. For the particular case of a parabolic profile, we find possible to cancel exactly the first harmonic and nearly cancel every other odd harmonics. In such case, the imprint amplitude is divided by 4 without any increase of Ω

Indium-tin-oxide thin film deposited by a dual ion beam assisted e-beam evaporation system

International Nuclear Information System (INIS)

Bae, J.W.; Kim, J.S.; Yeom, G.Y.

2001-01-01

Indium-tin-oxide (ITO) thin films were deposited on polycarbonate (PC) substrates at low temperatures (<90 deg. C) by a dual ion beam assisted e-beam evaporation system, where one gun (gun 1) is facing ITO flux and the other gun (gun 2) is facing the substrate. In this experiment, effects of rf power and oxygen flow rate of ion gun 2 on the electrical and optical properties of depositing ITO thin films were investigated. At optimal deposition conditions, ITO thin films deposited on the PC substrates larger than 20 cmx20 cm showed the sheet resistance of less than 40 Ω/sq., the optical transmittance of above 90%, and the uniformity of about 5%

Study on the Deposition Rate Depending on Substrate Position by Using Ion Beam Sputtering Deposition

Energy Technology Data Exchange (ETDEWEB)

Kim, Yonggi; Kim, Bomsok; Lee, Jaesang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

Ion beams have been used for over thirty years to modify materials in manufacturing of integrated circuits, and improving the corrosion properties of surfaces. Recently, the requirements for ion beam processes are becoming especially challenging in the following areas : ultra shallow junction formation for LSI fabrication, low damage high rate ion beam sputtering and smoothing, high quality functional surface treatment for electrical and optical properties. Ion beam sputtering is an attractive technology for the deposition of thin film coatings onto a broad variety of polymer, Si-wafer, lightweight substrates. Demand for the decoration metal is increasing. In addition, lightweight of parts is important, because of energy issues in the industries. Although a lot of researches have been done with conventional PVD methods for the deposition of metal or ceramic films on the surface of the polymer, there are still adhesion problems.

Electron pulsed beam induced processing of thin film surface by Nb3Ge deposited into a stainless steel tape

International Nuclear Information System (INIS)

Vavra, I.; Korenev, S.A.

1988-01-01

A surface of superconductive thin film of Nb 3 Ge deposited onto a stainless steel tape was processed using the electron beam technique. The electron beam used had the following parameters: beam current density from 400 to 1000 A/cm 2 ; beam energy 100 keV; beam impulse length 300 ns. By theoretical analysis it is shown that the heating of film surface is an adiabatic process. It corresponds to our experimental data and pictures showing a surface remelting due to electron beam influence. After beam processing the superconductive parameters of the film remain unchanged. Roentgenograms have been analysed of Nb 3 Ge film surface recrystallized due to electron beam influence

Summary and presentation of the international workshop on beam induced energy deposition (issues, concerns, solutions)

International Nuclear Information System (INIS)

Soundranayagam, R.

1991-11-01

This report discusses: energy deposition and radiation shielding in antriproton source at FNAL; radiation issues/problems at RHIC; radiation damage to polymers; radiation effects on optical fibre in the SSC tunnel; capabilities of the Brookhaven Radiation Effects Facility; the SSC interaction region; the FLUKA code system, modifications, recent extension and experimental verification; energy particle transport calculations and comparisons with experimental data; Los Alamos High Energy Transport code system; MCNP features and applications; intercomparison of Monte Carlo codes designed for simulation of high energy hadronic cascades; event generator, DTUJET-90 and DTUNUC; Preliminary hydrodynamic calculations of beam energy deposition; MESA code calculations of material response to explosive energy deposition; Smooth particle hydrodynamic; hydrodynamic effects and mass depletion phenomena in targets; beam dump: Beam sweeping and spoilers; Design considerations to mitigate effects of accidental beam dump; SSC beam abort and absorbed; beam abort system of SSC options; unconventional scheme for beam spoilers; low β quadrupoles: Energy deposition and radioactivation; beam induces energy deposition in the SSC components; extension of SSC-SR-1033 approach to radioactivation in LHC and SSC detectors; energy deposition in the SSC low-β IR-quads; beam losses and collimation in the LHC; and radiation shielding around scrapers

Laser damage resistance of hafnia thin films deposited by electron beam deposition, reactive low voltage ion plating, and dual ion beam sputtering

International Nuclear Information System (INIS)

Gallais, Laurent; Capoulade, Jeremie; Natoli, Jean-Yves; Commandre, Mireille; Cathelinaud, Michel; Koc, Cian; Lequime, Michel

2008-01-01

A comparative study is made of the laser damage resistance of hafnia coatings deposited on fused silica substrates with different technologies: electron beam deposition (from Hf or HfO2 starting material), reactive low voltage ion plating, and dual ion beam sputtering.The laser damage thresholds of these coatings are determined at 1064 and 355 nm using a nanosecond pulsed YAG laser and a one-on-one test procedure. The results are associated with a complete characterization of the samples: refractive index n measured by spectrophotometry, extinction coefficient k measured by photothermal deflection, and roughness measured by atomic force microscopy

SERS analysis of Ag nanostructures produced by ion-beam deposition

Science.gov (United States)

Atanasov, P. A.; Nedyalkov, N. N.; Nikov, Ru G.; Grüner, Ch; Rauschenbach, B.; Fukata, N.

2018-03-01

This study deals with the development of a novel technique for formation of advanced Ag nanostructures (NSs) to be applied to high-resolution analyses based on surface enhanced Raman scattering (SERS). It has direct bearing on human health and food quality, e.g., monitoring small amount or traces of pollutants or undesirable additives. Three types of nanostructured Ag samples were produced using ion-beam deposition at glancing angle (GLAD) on quartz. All fabricated structures were covered with BI-58 pesticide (dimethoate) or Rhodamine 6G (R6G) for testing their potential for use as substrates for (SERS).

Electron-beam deposition of vanadium dioxide thin films

Energy Technology Data Exchange (ETDEWEB)

Marvel, R.E.; Appavoo, K. [Vanderbilt University, Interdisciplinary Materials Science Program, Nashville, TN (United States); Choi, B.K. [Vanderbilt University, Department of Electrical Engineering and Computer Science, Nashville, TN (United States); Nag, J. [Vanderbilt University, Department of Physics and Astronomy, Nashville, TN (United States); Haglund, R.F. [Vanderbilt University, Interdisciplinary Materials Science Program, Nashville, TN (United States); Vanderbilt University, Institute for Nanoscale Science and Engineering, Nashville, TN (United States); Vanderbilt University, Department of Physics and Astronomy, Nashville, TN (United States)

2013-06-15

Developing a reliable and efficient fabrication method for phase-transition thin-film technology is critical for electronic and photonic applications. We demonstrate a novel method for fabricating polycrystalline, switchable vanadium dioxide thin films on glass and silicon substrates and show that the optical switching contrast is not strongly affected by post-processing annealing times. The method relies on electron-beam evaporation of a nominally stoichiometric powder, followed by fast annealing. As a result of the short annealing procedure we demonstrate that films deposited on silicon substrates appear to be smoother, in comparison to pulsed laser deposition and sputtering. However, optical performance of e-beam evaporated film on silicon is affected by annealing time, in contrast to glass. (orig.)

The role of low-energy electrons in focused electron beam induced deposition: four case studies of representative precursors

Directory of Open Access Journals (Sweden)

Rachel M. Thorman

2015-09-01

Full Text Available Focused electron beam induced deposition (FEBID is a single-step, direct-write nanofabrication technique capable of writing three-dimensional metal-containing nanoscale structures on surfaces using electron-induced reactions of organometallic precursors. Currently FEBID is, however, limited in resolution due to deposition outside the area of the primary electron beam and in metal purity due to incomplete precursor decomposition. Both limitations are likely in part caused by reactions of precursor molecules with low-energy (3, Pt(PF34, Co(CO3NO, and W(CO6. Through these case studies, it is evident that this combination of studies can provide valuable insight into potential mechanisms governing deposit formation in FEBID. Although further experiments and new approaches are needed, these studies are an important stepping-stone toward better understanding the fundamental physics behind the deposition process and establishing design criteria for optimized FEBID precursors.

Characterization of copper thin films prepared by metal self-ion beam sputter deposition

International Nuclear Information System (INIS)

Gotoh, Yasuhito; Amioka, Takao; Tsuji, Hiroshi; Ishikawa, Junzo

1994-01-01

New deposition technique, 'metal-ion beam self-sputtering' method has been developed. Using metal ions which is the same element with the target material, no contamination with noble gas atoms, which are often used in the conventional sputtering, will occur. In this paper, fundamental measurement of the film purity is reported. As a result of PIXE measurements, it was clarified that only slight amount of iron is incorporated in the films. (author)

Electron beam induced deposition of silacyclohexane and dichlorosilacyclohexane : The role of dissociative ionization and dissociative electron attachment in the deposition process

NARCIS (Netherlands)

Ragesh Kumar, T. P.; Hari, S.; Damodaran, Krishna K.; Ingólfsson, Oddur; Hagen, C.W.

2017-01-01

We present first experiments on electron beam induced deposition of silacyclohexane (SCH) and dichlorosilacyclohexane (DCSCH) under a focused high-energy electron beam (FEBID). We compare the deposition dynamics observed when growing pillars of high aspect ratio from these compounds and we

A review of basic phenomena and techniques for sputter-deposition of high temperature superconducting films

Energy Technology Data Exchange (ETDEWEB)

Auciello, O. (Microelectronics Center of North Carolina, Research Triangle Park, NC (USA) North Carolina State Univ., Raleigh, NC (USA). Dept. of Materials Science and Engineering); Ameen, M.S.; Kingon, A.I.; Lichtenwalner, D.J. (North Carolina State Univ., Raleigh, NC (USA). Dept. of Materials Science and Engineering); Krauss, A.R. (Argonne National Lab., IL (USA))

1990-01-01

The processes involved in plasma and ion beam sputter-deposition of high temperature superconducting thin films are critically reviewed. Recent advances in the development of these techniques are discussed in relation to basic physical phenomena, specific to each technique, which must be understood before high quality films can be produced. Control of film composition is a major issue in sputter-deposition of multicomponent materials. Low temperature processing of films is a common goal for each technique, particularly in relation to integrating high temperature superconducting films with the current microelectronics technology. It has been understood for some time that for Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} deposition, the most intensely studied high-{Tc} compound, incorporation of sufficient oxygen into the film during deposition is necessary to produce as-deposited superconducting films at relatively substrate temperatures. Recent results have shown that with the use of suitable buffer layers, high quality Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} sputtered films can be obtained on Si substrates without the need for post-deposition anneal processing. This review is mainly focussed on issues related to sputter-deposition of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} thin films, although representative results concerning the bismuth and thallium based compounds are included. 143 refs., 11 figs.

Space-qualified optical thin films by ion-beam-assisted deposition

International Nuclear Information System (INIS)

Hsiao, C.N.; Chen, H.P.; Chiu, P.K.; Lin, Y.W.; Chen, F.Z.; Tsai, D.P.

2013-01-01

Optical interference coatings designed for use in a space-grade multispectral assembly in a complementary metal-oxide‐semiconductor sensor were deposited on glass by ion-beam-assisted deposition for a Cassegrain-type space-based remote-sensing platform. The patterned multispectral assembly containing blue, green, red, near infrared, and panchromatic multilayer high/low alternated dielectric band-pass filter arrays in a single chip was fabricated by a mechanical mask and the photolithography process. The corresponding properties of the films were investigated by in situ optical monitoring and spectrometry. It was found that the optical properties were significantly improved by employing ion-beam-assisted deposition. The average transmittances were above 88% for the multispectral assembly, with a rejection transmittance of less than 1% in the spectral range 350–1100 nm. To estimate the optical stability of optical coatings for aerospace applications, a space environment assuming a satellite orbiting the Earth at an altitude of near 800 km was simulated by a Co 60 gamma (γ) radiation test. - Highlights: ►Parameters of optical filters were optimized by using admittance loci analysis. ►Higher index of refraction of films prepared by ion beam assisted deposition. ►The dielectric filters have acceptable resistance after γ radiation exposure

High mobility n-type organic thin-film transistors deposited at room temperature by supersonic molecular beam deposition

Energy Technology Data Exchange (ETDEWEB)

Chiarella, F., E-mail: fabio.chiarella@spin.cnr.it; Barra, M.; Ciccullo, F.; Cassinese, A. [CNR-SPIN and Physics Department, University of Naples, Piazzale Tecchio 80, I-80125 Naples (Italy); Toccoli, T.; Aversa, L.; Tatti, R.; Verucchi, R. [IMEM-CNR-FBK Division of Trento, Via alla Cascata 56/C, I-38123 Povo (Italy); Iannotta, S. [IMEM-CNR, Parco Area delle Scienze 37/A, I-43124 Parma (Italy)

2014-04-07

In this paper, we report on the fabrication of N,N′-1H,1H-perfluorobutil dicyanoperylenediimide (PDIF-CN{sub 2}) organic thin-film transistors by Supersonic Molecular Beam Deposition. The devices exhibit mobility up to 0.2 cm{sup 2}/V s even if the substrate is kept at room temperature during the organic film growth, exceeding by three orders of magnitude the electrical performance of those grown at the same temperature by conventional Organic Molecular Beam Deposition. The possibility to get high-mobility n-type transistors avoiding thermal treatments during or after the deposition could significantly extend the number of substrates suitable to the fabrication of flexible high-performance complementary circuits by using this compound.

Poly(methyl methacrylate) Composites with Size-selected Silver Nanoparticles Fabricated Using Cluster Beam Technique

DEFF Research Database (Denmark)

Muhammad, Hanif; Juluri, Raghavendra R.; Chirumamilla, Manohar

2016-01-01

based on cluster beam technique allowing the formation of monocrystalline size-selected silver nanoparticles with a ±5–7% precision of diameter and controllable embedment into poly (methyl methacrylate). It is shown that the soft-landed silver clusters preserve almost spherical shape with a slight...... tendency to flattening upon impact. By controlling the polymer hardness (from viscous to soft state) prior the cluster deposition and annealing conditions after the deposition the degree of immersion of the nanoparticles into polymer can be tuned, thus, making it possible to create composites with either...

Electron irradiation effects in amorphous antimony thin films obtained by cluster-beam deposition

Energy Technology Data Exchange (ETDEWEB)

Fuchs, G.; Treilleux, M.; Santos Aires, F.; Cabaud, B.; Melinon, P.; Hoareau, A. (Lyon-1 Univ., 69 - Villeurbanne (France))

1991-03-01

In order to understand the differences existing between films obtained with a classical molecular beam deposition (MBD) and the new low-energy cluster beam deposition (LECBD), transmission electron microscopy has been used to characterize the first stages of antimony LECBD. Antimony deposits are discontinuous and amorphous up to 2 nm in thickness. They are formed with isolated amorphous antimony particles surrounded by an amorphous antimony oxide shell. Moreover, under electron beam exposure in the microscope, an amorphous-crystal transformation has been observed in the oxide shell. Electron irradiation induces the formation of a crystallized antimony oxide (Sb{sub 2}O{sub 3}) around the amorphous antimony core. (author).

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices.

Science.gov (United States)

Batra, Nitin M; Patole, Shashikant P; Abdelkader, Ahmed; Anjum, Dalaver H; Deepak, Francis L; Costa, Pedro M F J

2015-11-06

The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode-interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode-nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

KAUST Repository

Batra, Nitin M; Patole, Shashikant P.; Abdelkader, Ahmed; Anjum, Dalaver H.; Deepak, Francis L; Da Costa, Pedro M. F. J.

2015-01-01

The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode–interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode–nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

KAUST Repository

Batra, Nitin M

2015-10-09

The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode–interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode–nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

Processing-structure-property relationships in electron beam physical vapor deposited yttria stabilized zirconia coatings

International Nuclear Information System (INIS)

Rao, D. Srinivasa; Valleti, Krishna; Joshi, S. V.; Janardhan, G. Ranga

2011-01-01

The physical and mechanical properties of yttria stabilized zirconia (YSZ) coatings deposited by the electron beam physical vapor deposition technique have been investigated by varying the key process variables such as vapor incidence angle and sample rotation speed. The tetragonal zirconia coatings formed under varying process conditions employed were found to have widely different surface and cross-sectional morphologies. The porosity, phase composition, planar orientation, hardness, adhesion, and surface residual stresses in the coated specimens were comprehensively evaluated to develop a correlation with the process variables. Under transverse scratch test conditions, the YSZ coatings exhibited two different crack formation modes, depending on the magnitude of residual stress. The influence of processing conditions on the coating deposition rate, column orientation angle, and adhesion strength has been established. Key relationships between porosity, hardness, and adhesion are also presented.

Structural properties and surface wettability of Cu-containing diamond-like carbon films prepared by a hybrid linear ion beam deposition technique

Energy Technology Data Exchange (ETDEWEB)

Guo, Peng; Sun, Lili; Li, Xiaowei [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Xu, Sheng [Gao Hong Coating Technology Co., Ltd, Huzhou 313000 (China); Ke, Peiling [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Aiying, E-mail: aywang@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

2015-06-01

Cu-containing diamond-like carbon (Cu-DLC) films were deposited on Si/glass substrate by a hybrid ion beam deposition system. The Cu concentration (0.1–39.7 at.%) in the film was controlled by varying the sputtering current. The microstructure and composition of Cu-DLC films were investigated systematically. The surface topography, roughness and surface wettability of the films were also studied. Results indicated that with increasing the Cu concentration, the water contact angle of the films changed from 66.8° for pure carbon film to more than 104.4° for Cu-DLC films with Cu concentration larger than 24.4 at.%. In the hydrophilic region, the polar surface energy decreased from 30.54 mJ/m{sup 2} for pure carbon film to 2.48 mJ/m{sup 2} for the film with Cu 7.0 at.%. - Highlights: • Cu-containing diamond-like carbon (DLC) films were deposited by a hybrid ion beam system. • Cu-containing DLC films exhibited a wide range of water contact angle. • The water contact angles vary with the surface energies and surface roughness.

Focused ion beam machining and deposition for nanofabrication

Energy Technology Data Exchange (ETDEWEB)

Davies, S T; Khamsehpour, B [Warwick Univ., Coventry (United Kingdom). Dept. of Engineering

1996-05-01

Focused ion beam micromatching (FIBM) and focused ion beam deposition (FIBD) enable spatially selective, maskless, patterning and processing of materials at extremely high levels of resolution. State-of-the-art focused ion beam (FIB) columns based on high brightness liquid metal ion source (LMIS) technology are capable of forming probes with dimensions of order 10 nm with a lower limit on spot size set by the inherent energy spread of the LMIS and the chromatic aberration of ion optical systems. The combination of high lateral and depth resolution make FIBM and FIBD powerful tools for nanotechnology applications. In this paper we present some methods of controlling FIBM and FIBD processes for nanofabrication purposes and discuss their limitations. (author).

Effect of annealing on the structural properties of electron beam deposited CIGS thin films

Energy Technology Data Exchange (ETDEWEB)

Venkatachalam, M. [Department of Electronics, Erode Arts College, Erode (India)], E-mail: prabhu7737@yahoo.com; Kannan, M.D.; Jayakumar, S.; Balasundaraprabhu, R. [Thin Film Center, PSG College of Technology, Coimbatore (India); Muthukumarasamy, N. [Department of Physics, Coimbatore Institute of Technology, Coimbatore (India)

2008-08-30

CIGS bulk compound of three different compositions CuIn{sub 0.85}Ga{sub 0.15}Se{sub 2}, CuIn{sub 0.80}Ga{sub 0.20}Se{sub 2} and CuIn{sub 0.75}Ga{sub 0.25}Se{sub 2} have been prepared by direct reaction of elemental copper, indium, gallium and selenium. CIGS thin films of the three compositions have been deposited onto glass and silicon substrates using the prepared bulk by electron beam deposition method. The structural properties of the deposited films have been studied using X-ray diffraction technique. The as-deposited CIGS films have been found to be amorphous in nature. To study the effect of annealing on the structural properties, the films have been annealed in vacuum of the order of 10{sup -5} Torr. The X-ray diffractograms of the annealed CIGS films exhibited peaks revealing that the annealed films are crystalline in nature with tetragonal chalcopyrite structure. The (112) peak corresponding to the chalcopyrite structure has been observed to be the dominating peak in all the annealed films. The position of the (112) peak and other peaks in the X-ray diffraction pattern has been observed to shift to higher values of 2{theta} with the increase of gallium concentration. The lattice parameter values 'a' and 'c' have been calculated and they are found to be dependent on the concentration of gallium in the films. The FWHM in the X-ray diffraction pattern is found to decrease with an increase in annealing temperature indicating that the crystalline nature of the CIGS improves with increase in annealing temperature. The films grown on silicon substrates have been found to be of better crystalline quality than those deposited on glass substrates. The micro structural parameters like grain size, dislocation density and strain have been evaluated. The chemical constituents present in the deposited CIGS films have been identified using energy dispersive X-ray analysis. The surface topographical study on the films has been performed by AFM. The

Ion beam deposited epitaxial thin silicon films

International Nuclear Information System (INIS)

Orrman-Rossiter, K.G.; Al-Bayati, A.H.; Armour, D.G.; Donnelly, S.E.; Berg, J.A. van den

1991-01-01

Deposition of thin films using low energy, mass-separated ion beams is a potentially important low temperature method of producing epitaxial layers. In these experiments silicon films were grown on Si (001) substrates using 10-200 eV 28 Si + and 30 Si + ions at substrate temperatures in the range 273-1073 K, under ultrahigh-vacuum conditions (deposition pressure -7 Pa). The film crystallinity was assessed in situ using medium energy ion scattering (MEIS). Films of crystallinity comparable to bulk samples were grown using 10-40 eV 28 Si + and 30 Si + ions at deposition temperatures in the range 623-823 K. These experiments confirmed the role of key experimental parameters such as ion energy, substrate temperature during deposition, and the surface treatment prior to deposition. It was found that a high temperature in situ anneal (1350-1450 K) gave the best results for epitaxial nucleation, whereas low energy (20-40 eV) Cl + ion bombardment resulted in amorphous film growth. The deposition energy for good epitaxial growth indicates that it is necessary to provide enough energy to induce local mobility but not to cause atomic displacements leading to the buildup of stable defects, e.g. divacancies, below the surface layer of the growing film. (orig.)

Studies of the Influence of Beam Profile and Cooling Conditions on the Laser Deposition of a Directionally-Solidified Superalloy

Directory of Open Access Journals (Sweden)

Shuo Yang

2018-02-01

Full Text Available In the laser deposition of single crystal and directionally-solidified superalloys, it is desired to form laser deposits with high volume fractions of columnar grains by suppressing the columnar-to-equiaxed transition efficiently. In this paper, the influence of beam profile (circular and square shapes and cooling conditions (natural cooling and forced cooling on the geometric morphology and microstructure of deposits were experimentally studied in the laser deposition of a directionally-solidified superalloy, IC10, and the mechanisms of influence were revealed through a numerical simulation of the thermal processes during laser deposition. The results show that wider and thinner deposits were obtained with the square laser beam than those with the circular laser beam, regardless of whether natural or forced cooling conditions was used. The heights and contact angles of deposits were notably increased due to the reduced substrate temperatures by the application of forced cooling for both laser beam profiles. Under natural cooling conditions, columnar grains formed epitaxially at both the center and the edges of the deposits with the square laser beam, but only at the center of the deposits with the circular laser beam; under forced cooling conditions, columnar grains formed at both the center and the edges of deposits regardless of the laser beam profile. The high ratios of thermal gradient and solidification velocity in the height direction of the deposits were favorable to forming deposits with higher volume fractions of columnar grains.

Electron-stimulated purification of platinum nanostructures grown via focused electron beam induced deposition

Directory of Open Access Journals (Sweden)

Brett B. Lewis

2015-04-01

Full Text Available Platinum–carbon nanostructures deposited via electron beam induced deposition from MeCpPt(IVMe3 are purified during a post-deposition electron exposure treatment in a localized oxygen ambient at room temperature. Time-dependent studies demonstrate that the process occurs from the top–down. Electron beam energy and current studies demonstrate that the process is controlled by a confluence of the electron energy loss and oxygen concentration. Furthermore, the experimental results are modeled as a 2nd order reaction which is dependent on both the electron energy loss density and the oxygen concentration. In addition to purification, the post-deposition electron stimulated oxygen purification process enhances the resolution of the EBID process due to the isotropic carbon removal from the as-deposited materials which produces high-fidelity shape retention.

Nanocomposite oxide thin films grown by pulsed energy beam deposition

International Nuclear Information System (INIS)

Nistor, M.; Petitmangin, A.; Hebert, C.; Seiler, W.

2011-01-01

Highly non-stoichiometric indium tin oxide (ITO) thin films were grown by pulsed energy beam deposition (pulsed laser deposition-PLD and pulsed electron beam deposition-PED) under low oxygen pressure. The analysis of the structure and electrical transport properties showed that ITO films with a large oxygen deficiency (more than 20%) are nanocomposite films with metallic (In, Sn) clusters embedded in a stoichiometric and crystalline oxide matrix. The presence of the metallic clusters induces specific transport properties, i.e. a metallic conductivity via percolation with a superconducting transition at low temperature (about 6 K) and the melting and freezing of the In-Sn clusters in the room temperature to 450 K range evidenced by large changes in resistivity and a hysteresis cycle. By controlling the oxygen deficiency and temperature during the growth, the transport and optical properties of the nanocomposite oxide films could be tuned from metallic-like to insulating and from transparent to absorbing films.

Depth profile analysis of thin TiOxNy films using standard ion beam analysis techniques and HERDA

International Nuclear Information System (INIS)

Markwitz, A.; Dytlewski, N.; Cohen, D.

1999-01-01

Ion beam assisted deposition is used to fabricate thin titanium oxynitride films (TiO x N y ) at Industrial Research (typical film thickness 100nm). At the Institute of Geological and Nuclear Sciences, the thin films are analysed using non-destructive standard ion beam analysis (IBA) techniques. High-resolution titanium depth profiles are measured with RBS using 1.5MeV 4 He + ions. Non-resonant nuclear reaction analysis (NRA) is performed for investigating the amounts of O and N in the deposited films using the reactions 16 O(d,p) 17 O at 920 keV and 14 N(d,α) 12 C at 1.4 MeV. Using a combination of these nuclear techniques, the stoichiometry as well as the thickness of the layers is revealed. However, when oxygen and nitrogen depth profiles are required for investigating stoichiometric changes in the films, additional nuclear analysis techniques such as heavy ion elastic recoil detection (HERDA) have to be applied. With HERDA, depth profiles of N, O, and Ti are measured simultaneously. In this paper comparative IBA measurement s of TiO x N y films with different compositions are presented and discussed

HfO2 as gate dielectric on Ge: Interfaces and deposition techniques

International Nuclear Information System (INIS)

Caymax, M.; Van Elshocht, S.; Houssa, M.; Delabie, A.; Conard, T.; Meuris, M.; Heyns, M.M.; Dimoulas, A.; Spiga, S.; Fanciulli, M.; Seo, J.W.; Goncharova, L.V.

2006-01-01

To fabricate MOS gate stacks on Ge, one can choose from a multitude of metal oxides as dielectric material which can be deposited by many chemical or physical vapor deposition techniques. As a few typical examples, we will discuss here the results from atomic layer deposition (ALD), metal organic CVD (MOCVD) and molecular beam deposition (MBD) using HfO 2 /Ge as materials model system. It appears that a completely interface layer free HfO 2 /Ge combination can be made in MBD, but this results in very bad capacitors. The same bad result we find if HfGe y (Hf germanides) are formed like in the case of MOCVD on HF-dipped Ge. A GeO x interfacial layer appears to be indispensable (if no other passivating materials are applied), but the composition of this interfacial layer (as determined by XPS, TOFSIMS and MEIS) is determining for the C/V quality. On the other hand, the presence of Ge in the HfO 2 layer is not the most important factor that can be responsible for poor C/V, although it can still induce bumps in C/V curves, especially in the form of germanates (Hf-O-Ge). We find that most of these interfacial GeO x layers are in fact sub-oxides, and that this could be (part of) the explanation for the high interfacial state densities. In conclusion, we find that the Ge surface preparation is determining for the gate stack quality, but it needs to be adapted to the specific deposition technique

Corrosion properties of aluminium coatings deposited on sintered NdFeB by ion-beam-assisted deposition

Energy Technology Data Exchange (ETDEWEB)

Mao Shoudong; Yang Hengxiu; Li Jinlong; Huang Feng [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 519 Zhuangshi Road, Ningbo 315201 (China); Song Zhenlun, E-mail: songzhenlun@nimte.ac.cn [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 519 Zhuangshi Road, Ningbo 315201 (China)

2011-04-15

Pure Al coatings were deposited by direct current (DC) magnetron sputtering to protect sintered NdFeB magnets. The effects of Ar{sup +} ion-beam-assisted deposition (IBAD) on the structure and the corrosion behaviour of Al coatings were investigated. The Al coating prepared by DC magnetron sputtering with IBAD (IBAD-Al-coating) had fewer voids than the coating without IBAD (Al-coating). The corrosion behaviour of the Al-coated NdFeB specimens was investigated by potentiodynamic polarisation, a neutral salt spray (NSS) test, and electrochemical impedance spectroscopy (EIS). The pitting corrosion of the Al coatings always began at the voids of the grain boundaries. Bombardment by the Ar{sup +} ion-beams effectively improved the corrosion resistance of the IBAD-Al-coating.

Corrosion properties of aluminum based alloys deposited by ion beam assisted deposition

International Nuclear Information System (INIS)

Enders, B.; Krauss, S.; Wolf, G.K.

1994-01-01

The replacement of cadmium coatings by other protective measures is an important task because of the environmentally detrimental properties of cadmium. Therefore, aluminum and aluminum alloy coatings containing elements such as silicon or magnesium with more positive or negative positions in the galvanic series in relation to pure aluminum were deposited by ion beam assisted deposition onto glass and low carbon steel. Pure aluminum films were deposited onto low carbon steel in order to study the influence of the ion-to-atom arrival ratio and the angle of ion incidence on the corrosion properties. For examination of the pitting behavior as a function of the concentration of alloying element, quasipotentiostatic current-potential and potentiostatic current-time plots were measured in chlorine-containing acetate buffer. It is shown that these alloys can protect steel substrates under uniform and pitting corrosion conditions considerably better than pure aluminum coatings. ((orig.))

Supersonic cluster beams: a powerful method for the deposition of nanostructured thin films with tailored properties

International Nuclear Information System (INIS)

Milani, P.

2002-01-01

By using a pulsed micro-plasma cluster source and by exploiting aero-dynamical effects typical of supersonic beams it is possible to obtain very high deposition rates with a control on neutral cluster mass distribution, allowing the deposition of thin films with controlled nanostructure. Due to high deposition rates, high lateral resolution, low temperature processing supersonic cluster beams can also be used for the micro and nano-patterning of cluster-assembled films when little or no post-growth manipulation or assembly is required. For example the nano and meso-structure of films obtained by carbon cluster beam deposition can be controlled by selecting in the beam the elemental building blocks, moreover functional properties such as field emission can be controlled and tailored. The use of supersonic cluster beams opens also new perspectives for the production of nano-structured films with novel physico-chemical and topological properties such as nano-structured carbon matrices containing carbide and transition metal particles. (Author)

Ultraviolet optical and microstructural properties of MgF2 and LaF3 coatings deposited by ion-beam sputtering and boat and electron-beam evaporation

Science.gov (United States)

Ristau, Detlev; Gunster, Stefan; Bosch, Salvador; Duparre, Angela; Masetti, Enrico; Ferre-Borrull, Josep; Kiriakidis, George; Peiro, Francesca; Quesnel, Etienne; Tikhonravov, Alexander

2002-06-01

Single layers of MgF2 and LaF3 were deposited upon superpolished fused-silica and CaF2 substrates by ion-beam sputtering (IBS) as well as by boat and electron beam (e-beam) evaporation and were characterized by a variety of complementary analytical techniques. Besides undergoing photometric and ellipsometric inspection, the samples were investigated at 193 and 633 nm by an optical scatter measurement facility. The structural properties were assessed with atomic-force microscopy, x-ray diffraction, TEM techniques that involved conventional thinning methods for the layers. For measurement of mechanical stress in the coatings, special silicon substrates were coated and analyzed. The dispersion behavior of both deposition materials, which was determined on the basis of various independent photometric measurements and data reduction techniques, is in good agreement with that published in the literature and with the bulk properties of the materials. The refractive indices of the MgF2 coatings ranged from 1.415 to 1.440 for the wavelength of the ArF excimer laser (193 nm) and from 1.435 to 1.465 for the wavelength of the F2 excimer laser (157 nm). For single layers of LaF3 the refractive indices extended from 1.67 to 1.70 at 193 nm to approx1.80 at 157 nm. The IBS process achieves the best homogeneity and the lowest surface roughness values (close to 1 nmrms) of the processes compared in the joint experiment. In contrast to MgF2 boat and e-beam evaporated coatings, which exhibit tensile mechanical stress ranging from 300 to 400 MPa, IBS coatings exhibit high compressive stress of as much as 910 MPa. A similar tendency was found for coating stress in LaF3 single layers. Experimental results are discussed with respect to the microstructural and compositional properties as well as to the surface topography of the coatings.

Direct deposition of gold on silicon with focused ion beams

Energy Technology Data Exchange (ETDEWEB)

Nebiker, P.W.; Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Muehle, R. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

1997-09-01

Irradiation with ions at very low energies (below 500 eV) no longer induces a removal of substrate material, but the ions are directly deposited on the surface. In this way, gold has been deposited on silicon with focused ion beam exposure and the properties of the film have been investigated with atomic force microscopy and Auger electron spectroscopy. (author) 3 figs., 1 ref.

Using the in situ lift-out technique to prepare TEM specimens on a single-beam FIB instrument

International Nuclear Information System (INIS)

Lekstrom, M; McLachlan, M A; Husain, S; McComb, D W; Shollock, B A

2008-01-01

Transmission electron microscope (TEM) specimens are today routinely prepared using focussed ion beam (FIB) instruments. Specifically, the lift-out method has become an increasingly popular technique and involves removing thin cross-sections from site-specific locations and transferring them to a TEM grid. This lift-out process can either be performed ex situ or in situ. The latter is mainly carried out on combined dual-beam FIB and scanning electron microscope (SEM) systems whereas conventional single-beam instruments often are limited to the traditional ex situ method. It is nevertheless desirable to enhance the capabilities of existing single-beam instruments to allow for in situ lift-out preparation to be performed since this technique offers a number of advantages over the older ex situ method. A single-beam FIB instrument was therefore modified to incorporate an in situ micromanipulator fitted with a tungsten needle, which can be attached to a cut-out FIB section using ion beam induced platinum deposition. This article addresses the issues of using an ion beam to monitor the in situ manipulation process as well as approaches that can be used to create stronger platinum welds between two objects, and finally, views on how to limit the extent of ion beam damage to the specimen surface.

A comparison of nodular defect seed geometeries from different deposition techniques

International Nuclear Information System (INIS)

Stolz, C.J.; Tench, R.J.; Kozlowski, M.R.; Fornier, A.

1995-01-01

A focused ion-beam milling instrument commonly utilized in the semiconductor industry for failure analysis and IC repair, is capable of cross-sectioning nodular defects. Utilizing the instrument's scanning on beam, high-resolution imaging of the seeds that initiate nodular defect growth is possible. In an attempt to understand the origins of these seeds, HfO 2 /SiO 2 and Ta 2 O 5 /SiO 2 coatings were prepared by a variety of coating vendors and different deposition processes including e-beam, magnetron sputtering, and ion beam sputtering. By studying the shape, depth, and composition of the seed, inferences of its origin can be drawn. The boundaries between the nodule and thin film provide insight into the mechanical stability of the nodule. Significant differences in the seed composition, geometry of nodular growth and mechanical stability of the defects for sputtered versus e-beam coatings are reported. Differences in seed shape were also observed from different coating vendors using e-beam deposition of HfO 2 /SiO 2 coatings

Neutral-beam deposition in large, finite-beta noncircular tokamak plasmas

International Nuclear Information System (INIS)

Wieland, R.M.; Houlberg, W.A.

1982-02-01

A parametric pencil beam model is introduced for describing the attenuation of an energetic neutral beam moving through a tokamak plasma. The nonnegligible effects of a finite beam cross section and noncircular shifted plasma cross sections are accounted for in a simple way by using a smoothing algorithm dependent linearly on beam radius and by including information on the plasma flux surface geometry explicitly. The model is benchmarked against more complete and more time-consuming two-dimensional Monte Carlo calculations for the case of a large D-shaped tokamak plasma with minor radius a = 120 cm and elongation b/a = 1.6. Deposition profiles are compared for deuterium beam energies of 120 to 150 keV, central plasma densities of 8 x 10 13 - 2 x 10 14 cm -3 , and beam orientation ranging from perpendicular to tangential to the inside wall

Ion beams application to modification of surface layer of solids with particular regard to IBAD method - ion beam assisted deposition realized in the INP; Zastosowanie wiazek jonowych do modyfikowania warstwy wierzchniej cial stalych, ze szczegolnym uwzglednieniem metody IBAD - Ion Beam Assisted Deposition, realizowanej w IFJ

Energy Technology Data Exchange (ETDEWEB)

Drwiega, M.; Lipinska, E.

1992-12-31

The different trends in ion engineering such as: dynamic ion mixing, ionized cluster beam deposition and ion beam assisted deposition are described. Some examples of properties of surface coatings are given and their applications are presented. The future of ion engineering is described. 48 refs, 12 figs, 4 tabs.

Microdroplet deposition through a film-free laser forward printing technique

International Nuclear Information System (INIS)

Patrascioiu, A.; Fernández-Pradas, J.M.; Morenza, J.L.; Serra, P.

2012-01-01

Highlights: ► Circular droplets are obtained for a wide range of focusing depths at fixed energy. ► Focusing depth variation study reveals two abrupt transitions in droplet diameter. ► Liquid ejection mechanism is mediated by two types of jets of different origin. ► Evolution of jets depends on the focusing depth accounting for the seen transitions. - Abstract: A recently developed film-free laser forward microprinting technique allows printing transparent and weakly absorbing liquids with high resolution and reproducibility. Its operating principle consists in the tight focusing of ultrashort laser pulses inside the liquid, and near its free surface, such that all the laser energy is absorbed in a small region around the beam waist. A cavitation bubble is then created inside the liquid, whose subsequent expansion results into the ejection of liquid. The collection of the ejected liquid on a substrate leads to the deposition of micron-sized droplets. In this work, we investigate a relevant process parameter of the technique, namely the laser focusing depth, and its influence on the morphology of the deposited droplets. The study reveals that for a fixed laser pulse energy there exists a relatively wide range of focusing depths at which circular and uniform droplets can be printed. The process of liquid ejection is also investigated. Time-resolved images reveal that liquid ejection proceeds through the formation of two kinds of jets which display clearly differentiated dynamics, and which could provide an interpretation for the dependence observed between the morphology of the deposited droplets and the laser focusing depth.

Simulation calculation for the energy deposition profile and the transmission fraction of intense pulsed electron beam at various incident angles

International Nuclear Information System (INIS)

Yang Hailiang; Qiu Aici; Zhang Jiasheng; Huang Jianjun; Sun Jianfeng

2002-01-01

The incident angles have a heavy effect on the intense pulsed electron beam energy deposition profile, energy deposition fraction and beam current transmission fraction in material. The author presents electron beam energy deposition profile and energy deposition fraction versus electron energy (0.5-2.0 MeV), at various incident angles for three aluminum targets of various thickness via theoretical calculation. The intense pulsed electron beam current transmission fractions versus electron energy (0.4-1.4 MeV) at various incident angles for three thickness of carbon targets were also theoretically calculated. The calculation results indicate that the deposition energy in unit mass of material surface layer increase with the rise of electron beam incident angle, and electron beam with low incident angle (closer to normal incident angle) penetrates deeper into the target material. The electron beams deposit more energy in unit mass of material surface layer at 60 degree-70 degree incident angle

Electron-beam induced deposition and autocatalytic decomposition of Co(CO3NO

Directory of Open Access Journals (Sweden)

Florian Vollnhals

2014-07-01

Full Text Available The autocatalytic growth of arbitrarily shaped nanostructures fabricated by electron beam-induced deposition (EBID and electron beam-induced surface activation (EBISA is studied for two precursors: iron pentacarbonyl, Fe(CO5, and cobalt tricarbonyl nitrosyl, Co(CO3NO. Different deposits are prepared on silicon nitride membranes and silicon wafers under ultrahigh vacuum conditions, and are studied by scanning electron microscopy (SEM and scanning transmission X-ray microscopy (STXM, including near edge X-ray absorption fine structure (NEXAFS spectroscopy. It has previously been shown that Fe(CO5 decomposes autocatalytically on Fe seed layers (EBID and on certain electron beam-activated surfaces, yielding high purity, polycrystalline Fe nanostructures. In this contribution, we investigate the growth of structures from Co(CO3NO and compare it to results obtained from Fe(CO5. Co(CO3NO exhibits autocatalytic growth on Co-containing seed layers prepared by EBID using the same precursor. The growth yields granular, oxygen-, carbon- and nitrogen-containing deposits. In contrast to Fe(CO5 no decomposition on electron beam-activated surfaces is observed. In addition, we show that the autocatalytic growth of nanostructures from Co(CO3NO can also be initiated by an Fe seed layer, which presents a novel approach to the fabrication of layered nanostructures.

Simultaneous Power Deposition Detection of Two EC Beams with the BIS Analysis in Moving TCV Plasmas

Science.gov (United States)

Curchod, L.; Pochelon, A.; Decker, J.; Felici, F.; Goodman, T. P.; Moret, J.-M.; Paley, J. I.

2009-11-01

Modulation of power amplitude is a widespread to determine the radial absorption profile of externally launched power in fusion plasmas. There are many techniques to analyze the plasma response to such a modulation. The break-in-slope (BIS) analysis can draw an estimated power deposition profile for each power step up. In this paper, the BIS analysis is used to monitor the power deposition location of one or two EC power beams simultaneously in a non-stationary plasma being displaced vertically in the TCV tokamak vessel. Except from radial discrepancies, the results have high time resolution and compare well with simulations from the R2D2-C3PO-LUKE ray-tracing and Fokker-Planck code suite.

High-rate deposition of SI absorber layers by electron beam evaporation and first electron beam crystallization tests

OpenAIRE

Saager, Stefan; Ben Yaala, Marwa; Heinß, Jens-Peter; Temmler, Dietmar; Pfefferling, Bert; Metzner, Christoph

2014-01-01

In earlier electron beam physical vapor deposition tests (EB-PVD), using a conventional copper crucible (A), high Si deposition rates at relatively high EB power together with a contamination level of 1016 cm-3 are demonstrated. To improve the rate vs. EB power relation as well as the Si layer purity, two alternative high rate EBPVD methods are investigated and reported here - a contact-less crucible setup (B) and a crucible-free setup (C).In these experiments comparable deposition rates of ~...

Laser assisted modification and chemical metallization of electron-beam deposited ceria thin films

International Nuclear Information System (INIS)

Krumov, E.; Starbov, N.; Starbova, K.; Perea, A.; Solis, J.

2009-01-01

Excimer laser processing is applied for tailoring the surface morphology and phase composition of CeO 2 ceramic thin films. E-beam evaporation technique is used to deposit samples on stainless steel and silicate glass substrates. The films are then irradiated with ArF* excimer laser pulses under different exposure conditions. Scanning electron microscopy, optical spectrophotometry, X-ray diffractometry and EDS microanalysis are used to characterize the non-irradiated and laser-processed films. Upon UV laser exposure there is large increase of the surface roughness that is accompanied by photo-darkening and ceria reduction. It is shown that the laser induced changes in the CeO 2 films facilitate the deposition of metal nano-aggregates in a commercial copper electroless plating bath. The significance of laser modification as a novel approach for the production of CeO 2 based thin film catalysts is discussed.

Laser assisted modification and chemical metallization of electron-beam deposited ceria thin films

Energy Technology Data Exchange (ETDEWEB)

Krumov, E., E-mail: emodk@clf.bas.bg [Central Laboratory of Photoprocesses ' Acad. Jordan Malinowski' , Bulgarian Academy of Sciences, Acad. Georgy Bonchev Str., bl. 109, 1113 Sofia (Bulgaria); Starbov, N.; Starbova, K. [Central Laboratory of Photoprocesses ' Acad. Jordan Malinowski' , Bulgarian Academy of Sciences, Acad. Georgy Bonchev Str., bl. 109, 1113 Sofia (Bulgaria); Perea, A.; Solis, J. [Instituto de Optica ' Daza de Valdes' , CSIC, 28006 Madrid (Spain)

2009-11-15

Excimer laser processing is applied for tailoring the surface morphology and phase composition of CeO{sub 2} ceramic thin films. E-beam evaporation technique is used to deposit samples on stainless steel and silicate glass substrates. The films are then irradiated with ArF* excimer laser pulses under different exposure conditions. Scanning electron microscopy, optical spectrophotometry, X-ray diffractometry and EDS microanalysis are used to characterize the non-irradiated and laser-processed films. Upon UV laser exposure there is large increase of the surface roughness that is accompanied by photo-darkening and ceria reduction. It is shown that the laser induced changes in the CeO{sub 2} films facilitate the deposition of metal nano-aggregates in a commercial copper electroless plating bath. The significance of laser modification as a novel approach for the production of CeO{sub 2} based thin film catalysts is discussed.

Effects of deposition and post-annealing conditions on electrical properties and thermal stability of TiAlN films by ion beam sputter deposition

International Nuclear Information System (INIS)

Lee, S.-Y.; Wang, S.-C.; Chen, J.-S.; Huang, J.-L.

2006-01-01

TiAlN films were deposited by ion beam sputter deposition (IBSD) using a Ti-Al (90/10) alloy target in a nitrogen atmosphere on thermal oxidized Si wafers. Effects of ion beam voltage, substrate temperature (T s ) and post-annealing conditions on electrical properties and oxidation resistance of TiAlN films were studied. According to the experimental results, the proper kinetic energy provided good crystallinity and a dense structure of the films. Because of their better crystallinity and predomination of (200) planes, TiAlN films deposited with 900 V at low T s (50 deg. C) have shown lower resistivity than those at high T s (250 deg. C). They also showed better oxidation resistance. If the beam voltage was too high, it caused some damage to the film surfaces, which caused poor oxidation resistance of films. When sufficient kinetic energy was provided by the beam voltage, the mobility of adatoms was too high due to their extra thermal energy, thus reducing the crystallinity and structure density of the films. A beam voltage of 900 V and a substrate temperature of 50 deg. C were the optimum deposition conditions used in this research. They provided good oxidation resistance and low electrical resistivity for IBSD TiAlN films

Comparative study of LaNiO$_3$/LaAlO$_3$ heterostructures grown by pulsed laser deposition and oxide molecular beam epitaxy

OpenAIRE

Wrobel, F.; Mark, A. F.; Christiani, G.; Sigle, W.; Habermeier, H. -U.; van Aken, P. A.; Logvenov, G.; Keimer, B.; Benckiser, E.

2017-01-01

Variations in growth conditions associated with different deposition techniques can greatly affect the phase stability and defect structure of complex oxide heterostructures. We synthesized superlattices of the paramagnetic metal LaNiO3 and the large band gap insulator LaAlO3 by atomic layer-by-layer molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) and compared their crystallinity, microstructure as revealed by high-resolution transmission electron microscopy images and resistiv...

Three-dimensional nanofabrication by electron-beam-induced deposition using 200-keV electrons in scanning transmission electron microscope

International Nuclear Information System (INIS)

Liu, Z.Q.; Mitsuishi, K.; Furuya, K.

2005-01-01

Attempts were made to fabricate three-dimensional nanostructures on and out of a substrate by electron-beam-induced deposition in a 200-kV scanning transmission electron microscope. Structures with parallel wires over the substrate surface were difficult to fabricate due to the direct deposition of wires on both top and bottom surfaces of the substrate. Within the penetration depth of the incident electron beam, nanotweezers were fabricated by moving the electron beam beyond different substrate layers. Combining the deposition of self-supporting wires and self-standing tips, complicated three-dimensional doll-like, flag-like, and gate-like nanostructures that extend out of the substrate were successfully fabricated with one-step or multi-step scans of the electron beam. Effects of coarsening, nucleation, and distortion during electron-beam-induced deposition are discussed. (orig.)

Lead-doped electron-beam-deposited Bi-Sr-Ca-Cu-O superconducting thin films

Energy Technology Data Exchange (ETDEWEB)

Agnihotry, S.A.; Saini, K.K.; Kant, C.; Sharma, C.P.; Ekbote, S.N.; Asthana, P.; Nagpal, K.C.; Chandra, S. (National Physical Lab., New Delhi (India))

1991-03-20

Superconducting thin films of the lead-doped Bi-Sr-Ca-Cu-O system have been prepared on (100) single-crystal SrTiO{sub 3} substrates by an electron beam deposition technique using a single sintered pellet as the evaporation source. As-deposited films are amorphous and non-superconducting; post-deposition annealing at an optimized temperature in air has been found to result in crystalline and superconducting films. The superconducting characteristics of the films have been observed to be sensitive not only to the duration and temperature of post-deposition annealing but also to the lead content and the sintering parameters for the pellet to be used as the evaporation source. A pellet with nominal composition Bi{sub 3}Pb{sub 1}Sr{sub 3}Ca{sub 3}Cu{sub 4}O{sub y} that had been sintered for 200 h zero resistivity Tc{sup 0}=112 K. However, films deposited using such a pellet as the evaporation source had Tc{sup 0} {approx equal} 73-78 K, as had the films deposited from a pellet without any lead. We investigated systematically films deposited from pellets with more lead and sintered for different durations. It is evident from these investigations that pellets with nominal composition Bi{sub 3}Pb{sub 2}Sr{sub 3}Ca{sub 3}Cu{sub 4}O{sub y}, i.e. with an excess of lead, and sintered for about 75 h when used as the evaporation source yield films with Tc{sup 0} {approx equal} 100 K when annealed between 835 and 840deg C for an optimized long duration. The films are characterized by X-ray diffraction and energy-dispersive spectroscopy techniques and have been found to be highly c axis oriented. The effect of lead in promoting a high Tc{sup 0}=110 K phase seems to be similar to that in bulk ceramics. (orig.).

Ohmic contact junction of carbon nanotubes fabricated by in situ electron beam deposition

International Nuclear Information System (INIS)

Wang, Y G; Wang, T H; Lin, X W; Dravid, V P

2006-01-01

We present experimental evidence of in situ fabrication of multi-walled carbon nanotube junctions via electron beam induced deposition. The tip-to-tip interconnection of the nanotubes involves the alignment of two nanotubes via a piezodriven nanomanipulator and nano-welding by electron beam deposition. Hydrocarbon contamination from the pump oil vapour of the vacuum system of the TEM chamber was used as the solder; this is superior to the already available metallic solders because its composition is identical to the carbon nanotube. The hydrocarbon deposition, with perfect wettability, on the nanotubes establishes strong mechanical binding between the two nanotubes to form an integrated structure. Consequently, the nanotubes cross-linked by the hydrocarbon solder produce good electrical and mechanical connections. The joint dimension was determined by the size of the electron beam, which results in a sound junction with well-defined geometry and the smallest junction size obtained so far. In situ electric measurement showed a linear current-voltage property for the multi-walled nanotube junction

Ion beam techniques in arts and archaeology

International Nuclear Information System (INIS)

Qin Guangyong; Pan Xianjia; Sun Zhongtian; Gao Zhengyao

1991-01-01

The ion beam techniques used in studies of arts and archaeology are compared with other analytical techniques. Some examples are specially selected to illustrate the achievements and trends of the techniques in this field

Experience with Kicker Beam Coupling Reduction Techniques

CERN Document Server

Gaxiola, Enrique; Caspers, Friedhelm; Ducimetière, Laurent; Kroyer, Tom

2005-01-01

SPS beam impedance is still one of the worries for operation with nominal LHC beam over longer periods, once the final configuration will be installed in 2006. Several CERN SPS kickers suffer from significant beam induced ferrite heating. In specific cases, for instance beam scrubbing, the temperature of certain ferrite yokes went beyond the Curie point. Several retrofit impedance reduction techniques have been investigated theoretically and with practical tests. We report on experience gained during the 2004 SPS operation with resistively coated ceramic inserts in terms of kicker heating, pulse rise time, operating voltage, and vacuum behaviour. For another technique using interleaved metallic stripes we observed significant improvements in bench measurements. Advantages and drawbacks of both methods and potential combinations of them are discussed and simulation as well as measured data are shown. Prospects for further improvements beyond 2006 are briefly outlined.

Microdroplet deposition through a film-free laser forward printing technique

Energy Technology Data Exchange (ETDEWEB)

Patrascioiu, A.; Fernandez-Pradas, J.M.; Morenza, J.L. [Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Serra, P., E-mail: pserra@ub.edu [Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain)

2012-09-15

Highlights: Black-Right-Pointing-Pointer Circular droplets are obtained for a wide range of focusing depths at fixed energy. Black-Right-Pointing-Pointer Focusing depth variation study reveals two abrupt transitions in droplet diameter. Black-Right-Pointing-Pointer Liquid ejection mechanism is mediated by two types of jets of different origin. Black-Right-Pointing-Pointer Evolution of jets depends on the focusing depth accounting for the seen transitions. - Abstract: A recently developed film-free laser forward microprinting technique allows printing transparent and weakly absorbing liquids with high resolution and reproducibility. Its operating principle consists in the tight focusing of ultrashort laser pulses inside the liquid, and near its free surface, such that all the laser energy is absorbed in a small region around the beam waist. A cavitation bubble is then created inside the liquid, whose subsequent expansion results into the ejection of liquid. The collection of the ejected liquid on a substrate leads to the deposition of micron-sized droplets. In this work, we investigate a relevant process parameter of the technique, namely the laser focusing depth, and its influence on the morphology of the deposited droplets. The study reveals that for a fixed laser pulse energy there exists a relatively wide range of focusing depths at which circular and uniform droplets can be printed. The process of liquid ejection is also investigated. Time-resolved images reveal that liquid ejection proceeds through the formation of two kinds of jets which display clearly differentiated dynamics, and which could provide an interpretation for the dependence observed between the morphology of the deposited droplets and the laser focusing depth.

BIRTH: a beam deposition code for non-circular tokamak plasmas

International Nuclear Information System (INIS)

Otsuka, Michio; Nagami, Masayuki; Matsuda, Toshiaki

1982-09-01

A new beam deposition code has been developed which is capable of calculating fast ion deposition profiles including the orbit correction. The code incorporates any injection geometry and a non-circular cross section plasma with a variable elongation and an outward shift of the magnetic flux surface. Typical cpu time on a DEC-10 computer is 10 - 20 seconds and 5 - 10 seconds with and without the orbit correction, respectively. This is shorter by an order of magnitude than that of other codes, e.g., Monte Carlo codes. The power deposition profile calculated by this code is in good agreement with that calculated by a Monte Carlo code. (author)

Energy deposition profile on ISOLDE Beam Dumps by FLUKA simulations

CERN Document Server

Vlachoudis, V

2014-01-01

In this report an estimation of the energy deposited on the current ISOLDE beam dumps obtained by means of FLUKA simulation code is presented. This is done for both ones GPS and HRS. Some estimations of temperature raise are given based on the assumption of adiabatic increase from energy deposited by the impinging protons. However, the results obtained here in relation to temperature are only a rough estimate. They are meant to be further studied through thermomechanical simulations using the energyprofiles hereby obtained.

Nano/micro particle beam for ceramic deposition and mechanical etching

International Nuclear Information System (INIS)

Chun, Doo-Man; Kim, Min-Saeng; Kim, Min-Hyeng; Ahn, Sung-Hoon; Yeo, Jun-Cheol; Lee, Caroline Sunyong

2010-01-01

Nano/micro particle beam (NPB) is a newly developed ceramic deposition and mechanical etching process. Additive (deposition) and subtractive (mechanical etching) processes can be realized in one manufacturing process using ceramic nano/micro particles. Nano- or micro-sized powders are sprayed through the supersonic nozzle at room temperature and low vacuum conditions. According to the process conditions, the ceramic powder can be deposited on metal substrates without thermal damage, and mechanical etching can be conducted in the same process with a simple change of process conditions and powders. In the present work, ceramic aluminum oxide (Al 2 O 3 ) thin films were deposited on metal substrates. In addition, the glass substrate was etched using a mask to make small channels. Deposited and mechanically etched surface morphology, coating thickness and channel depth were investigated. The test results showed that the NPB provides a feasible additive and subtractive process using ceramic powders.

Cuprous oxide thin films grown by hydrothermal electrochemical deposition technique

International Nuclear Information System (INIS)

Majumder, M.; Biswas, I.; Pujaru, S.; Chakraborty, A.K.

2015-01-01

Semiconducting cuprous oxide films were grown by a hydrothermal electro-deposition technique on metal (Cu) and glass (ITO) substrates between 60 °C and 100 °C. X-ray diffraction studies reveal the formation of cubic cuprous oxide films in different preferred orientations depending upon the deposition technique used. Film growth, uniformity, grain size, optical band gap and photoelectrochemical response were found to improve in the hydrothermal electrochemical deposition technique. - Highlights: • Cu 2 O thin films were grown on Cu and glass substrates. • Conventional and hydrothermal electrochemical deposition techniques were used. • Hydrothermal electrochemical growth showed improved morphology, thickness and optical band gap

Electron beam induced deposition of silacyclohexane and dichlorosilacyclohexane: the role of dissociative ionization and dissociative electron attachment in the deposition process

Directory of Open Access Journals (Sweden)

Ragesh Kumar T P

2017-11-01

Full Text Available We present first experiments on electron beam induced deposition of silacyclohexane (SCH and dichlorosilacyclohexane (DCSCH under a focused high-energy electron beam (FEBID. We compare the deposition dynamics observed when growing pillars of high aspect ratio from these compounds and we compare the proximity effect observed for these compounds. The two precursors show similar behaviour with regards to fragmentation through dissociative ionization in the gas phase under single-collision conditions. However, while DCSCH shows appreciable cross sections with regards to dissociative electron attachment, SCH is inert with respect to this process. We discuss our deposition experiments in context of the efficiency of these different electron-induced fragmentation processes. With regards to the deposition dynamics, we observe a substantially faster growth from DCSCH and a higher saturation diameter when growing pillars with high aspect ratio. However, both compounds show similar behaviour with regards to the proximity effect. With regards to the composition of the deposits, we observe that the C/Si ratio is similar for both compounds and in both cases close to the initial molecular stoichiometry. The oxygen content in the DCSCH deposits is about double that of the SCH deposits. Only marginal chlorine is observed in the deposits of from DCSCH. We discuss these observations in context of potential approaches for Si deposition.

Lifetime obtained by ion beam assisted deposition

Energy Technology Data Exchange (ETDEWEB)

Chakaroun, M. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France); Antony, R. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France)], E-mail: remi.antony@unilim.fr; Taillepierre, P.; Moliton, A. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France)

2007-09-15

We have fabricated green organic light-emitting diodes based on tris-(8-hydroxyquinoline)aluminium (Alq3) thin films. In order to favor the charge carriers transport from the anode, we have deposited a N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) layer (hole transport layer) on a ITO anode. Cathode is obtained with a calcium layer covered with a silver layer. This silver layer is used to protect the other layers against oxygen during the OLED use. All the depositions are performed under vacuum and the devices are not exposed to air during their realisation. In order to improve the silver layer characteristics, we have realized this layer with the ion beam assisted deposition process. The aim of this process is to densify the layer and then reduce the permeation of H{sub 2}O and O{sub 2}. We have used argon ions to assist the silver deposition. All the OLEDs optoelectronic characterizations (I = f(V), L = f(V)) are performed in the ambient air. We compare the results obtained with the assisted layer with those obtained with a classical cathode realized by thermal unassisted evaporation. We have realized lifetime measurements in the ambient air and we discuss about the assisted layer influence on the OLEDs performances.

Low resistivity Pt interconnects developed by electron beam assisted deposition using novel gas injector system

International Nuclear Information System (INIS)

Dias, R J; Romano-Rodriguez, A; O'Regan, C; Holmes, J D; Petkov, N; Thrompenaars, P; Mulder, J J L

2012-01-01

Electron beam-induced deposition (EBID) is a direct write process where an electron beam locally decomposes a precursor gas leaving behind non-volatile deposits. It is a fast and relatively in-expensive method designed to develop conductive (metal) or isolating (oxide) nanostructures. Unfortunately the EBID process results in deposition of metal nanostructures with relatively high resistivity because the gas precursors employed are hydrocarbon based. We have developed deposition protocols using novel gas-injector system (GIS) with a carbon free Pt precursor. Interconnect type structures were deposited on preformed metal architectures. The obtained structures were analysed by cross-sectional TEM and their electrical properties were analysed ex-situ using four point probe electrical tests. The results suggest that both the structural and electrical characteristics differ significantly from those of Pt interconnects deposited by conventional hydrocarbon based precursors, and show great promise for the development of low resistivity electrical contacts.

Sputtering. [as deposition technique in mechanical engineering

Science.gov (United States)

Spalvins, T.

1976-01-01

This paper primarily reviews the potential of using the sputtering process as a deposition technique; however, the manufacturing and sputter etching aspects are also discussed. Since sputtering is not regulated by classical thermodynamics, new multicomponent materials can be developed in any possible chemical composition. The basic mechanism for dc and rf sputtering is described. Sputter-deposition is described in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter-etching, target geometry (coating complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also described are some of the specific industrial areas which are turning to sputter-deposition techniques.

Effect of ion beam irradiation on the structure of ZnO films deposited by a dc arc plasmatron.

Science.gov (United States)

Penkov, Oleksiy V; Lee, Heon-Ju; Plaksin, Vadim Yu; Ko, Min Gook; Joa, Sang Beom; Yim, Chan Joo

2008-02-01

The deposition of polycrystalline ZnO film on a cold substrate was performed by using a plasmatron in rough vacuum condition. Low energy oxygen ion beam generated by a cold cathode ion source was introduced during the deposition process. The change of film property on the ion beam energy was checked. It is shown that irradiation by 200 eV ions improves crystalline structure of the film. Increasing of ion beam energy up to 400 eV leads to the degradation of a crystalline structure and decreases the deposition rate.

Studies on ion scattering and sputtering processes relevant to ion beam sputter deposition of multicomponent thin films

International Nuclear Information System (INIS)

Auciello, O.; Ameen, M.S.; Kingon, A.I.

1989-01-01

Results from computer simulation and experiments on ion scattering and sputtering processes in ion beam sputter deposition of high Tc superconducting and ferroelectric thin films are presented. It is demonstrated that scattering of neutralized ions from the targets can result in undesirable erosion of, and inert gas incorporation in, the growing films, depending on the ion/target atom ass ratio and ion beam angle of incidence/target/substrate geometry. The studies indicate that sputtering Kr + or Xe + ions is preferable to the most commonly used Ar + ions, since the undesirable phenomena mentioned above are minimized for the first two ions. These results are used to determine optimum sputter deposition geometry and ion beam parameters for growing multicomponent oxide thin films by ion beam sputter-deposition. 10 refs., 5 figs

Ion beam assisted deposition of nano-structured C:Ni films

Energy Technology Data Exchange (ETDEWEB)

Abrasonis, G.; Muecklich, A.; Heller, R.; Heinig, K.H.; Gemming, S.; Moeller, W. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Krause, M. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Institute of Physics, TU Dresden (Germany)

2012-07-01

Nanostructures influence material properties dramatically due to size, shape and interface effects. Thus the control of the structure at the nanoscale is a key issue in nanomaterials science. The interaction of hyperthermal ions with solids is confined to the nanometer scale. Thus, it can be used to control the morphology evolution during multiphase film deposition. Ion-induced displacements occur in a thin surface layer of the growing film where they increase the atomic mobility for the phase separation. Here the growth-structure relationship of C:Ni (15 at.%) nanocomposite films grown by oblique incidence (45 ) ion beam assisted deposition is reported. The influences of the flux of an assisting Ar+ ion beam (0-140 eV) as well as of an elevated substrate temperature have been studied. The formation of elongated nickel nanoparticles is strongly promoted by the ion beam assistance. Moreover, the metal nanocolumns no longer align with the advancing surface, but with the incoming ions. A window of conditions is established within which the ion assistance leads to the formation of regular composition modulations with a well defined periodicity and tilt. As the dominating driving force for the pattern formation is of physical origin, this approach might be applicable to other immiscible systems.

3D magnetic nanostructures grown by focused electron and ion beam induced deposition

Science.gov (United States)

Fernandez-Pacheco, Amalio

Three-dimensional nanomagnetism is an emerging research area, where magnetic nanostructures extend along the whole space, presenting novel functionalities not limited to the substrate plane. The development of this field could have a revolutionary impact in fields such as electronics, the Internet of Things or bio-applications. In this contribution, I will show our recent work on 3D magnetic nanostructures grown by focused electron and ion beam induced deposition. This 3D nano-printing techniques, based on the local chemical vapor deposition of a gas via the interaction with electrons and ions, makes the fabrication of complex 3D magnetic nanostructures possible. First, I will show how by exploiting different growth regimes, suspended Cobalt nanowires with modulated diameter can be patterned, with potential as domain wall devices. Afterwards, I will show recent results where the synthesis of Iron-Gallium alloys can be exploited in the field of artificial multiferroics. Moreover, we are developing novel methodologies combining physical vapor deposition and 3D nano-printing, creating Permalloy 3D nanostrips with controllable widths and lengths up to a few microns. This approach has been extended to more complex geometries by exploiting advanced simulation growth techniques combining Monte Carlo and continuum model methods. Throughout the talk, I will show the methodology we are following to characterize 3D magnetic nanostructures, by combining magneto-optical Kerr effect, scanning probe microscopy and electron and X-R magnetic imaging, and I will highlight some of the challenges and opportunities when studying these structures. I acknowledge funding from EPSRC and the Winton Foundation.

Electron Beam Polarization Measurement Using Touschek Lifetime Technique

Energy Technology Data Exchange (ETDEWEB)

Sun, Changchun; /Duke U., DFELL; Li, Jingyi; /Duke U., DFELL; Mikhailov, Stepan; /Duke U., DFELL; Popov, Victor; /Duke U., DFELL; Wu, Wenzhong; /Duke U., DFELL; Wu, Ying; /Duke U., DFELL; Chao, Alex; /SLAC; Xu, Hong-liang; /Hefei, NSRL; Zhang, Jian-feng; /Hefei, NSRL

2012-08-24

Electron beam loss due to intra-beam scattering, the Touschek effect, in a storage ring depends on the electron beam polarization. The polarization of an electron beam can be determined from the difference in the Touschek lifetime compared with an unpolarized beam. In this paper, we report on a systematic experimental procedure recently developed at Duke FEL laboratory to study the radiative polarization of a stored electron beam. Using this technique, we have successfully observed the radiative polarization build-up of an electron beam in the Duke storage ring, and determined the equilibrium degree of polarization and the time constant of the polarization build-up process.

Photon beam convolution using polyenergetic energy deposition kernels

International Nuclear Information System (INIS)

Hoban, P.W.; Murray, D.C.; Round, W.H.

1994-01-01

In photon beam convolution calculations where polyenergetic energy deposition kernels (EDKs) are used, the primary photon energy spectrum should be correctly accounted for in Monte Carlo generation of EDKs. This requires the probability of interaction, determined by the linear attenuation coefficient, μ, to be taken into account when primary photon interactions are forced to occur at the EDK origin. The use of primary and scattered EDKs generated with a fixed photon spectrum can give rise to an error in the dose calculation due to neglecting the effects of beam hardening with depth. The proportion of primary photon energy that is transferred to secondary electrons increases with depth of interaction, due to the increase in the ratio μ ab /μ as the beam hardens. Convolution depth-dose curves calculated using polyenergetic EDKs generated for the primary photon spectra which exist at depths of 0, 20 and 40 cm in water, show a fall-off which is too steep when compared with EGS4 Monte Carlo results. A beam hardening correction factor applied to primary and scattered 0 cm EDKs, based on the ratio of kerma to terma at each depth, gives primary, scattered and total dose in good agreement with Monte Carlo results. (Author)

The Investigation of E-beam Deposited Titanium Dioxide and Calcium Titanate Thin Films

Directory of Open Access Journals (Sweden)

Kristina BOČKUTĖ

2013-09-01

Full Text Available Thin titanium dioxide and calcium titanate films were deposited using electron beam evaporation technique. The substrate temperature during the deposition was changed from room temperature to 600 °C to test its influence on TiO2 film formation and optical properties. The properties of CaTiO3 were investigated also. For the evaluation of the structural properties the formed thin ceramic films were studied by X-ray diffraction (XRD, energy dispersive spectrometry (EDS, scanning electron microscopy (SEM and atomic force microscopy (AFM. Optical properties of thin TiO2 ceramics were investigated using optical spectroscope and the experimental data were collected in the ultraviolet-visible and near-infrared ranges with a step width of 1 nm. Electrical properties were investigated by impedance spectroscopy.It was found that substrate temperature has influence on the formed thin films density. The density increased when the substrate temperature increased. Substrate temperature had influence on the crystallographic, structural and optical properties also. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.1805

Optical properties of YbF3-CaF2 composite thin films deposited by electron-beam evaporation

Science.gov (United States)

Wang, Songlin; Mi, Gaoyuan; Zhang, Jianfu; Yang, Chongmin

2018-03-01

We studied electron-beam evaporated YbF3-CaF2 composite films on ZnS substrate at different deposition parameters. The optical properties of films have been fitted, the surface roughness have been measured by AFM. The results of experiments indicated that increased the refractive indices, extinction coefficients, and surface roughness at higher deposition rate. The refractive index of composite film deposited by electron-beam evaporation with assisted-ion source was obviously higher than it without assisted-ion source.

Effects of ion beam bombardment of carbon thin films deposited onto tungsten carbide and tool steels

Energy Technology Data Exchange (ETDEWEB)

Awazu, Kaoru; Yoshida, Hiroyuki [Industrial Research Inst. of Ishikawa (Japan); Watanabe, Hiroshi [Gakushuin Univ., Tokyo (Japan); Iwaki, Masaya; Guzman, L [RIKEN, Saitama (Japan)

1992-04-15

A study was made of the effects of argon ion bombardment of carbon thin films deposited onto WC and tool steels. Carbon thin film deposition was performed at various temperatures ranging from 200degC to 350degC, using C{sub 6}H{sub 6} gas. Argon ion beam bombardment of the films was carried out at an energy of 150 keV with a dose of 1x10{sup 16} ions cm{sup -2}. The hardness and adhesion of the films were measured by means of Knoop hardness and scratch tests respectively. The structure of the carbon films was estimated by laser Raman spectroscopy, and the relations were investigated between the mechanical properties and the structure of the films. The hardness of carbon thin films increases as their deposition temperature decreases; this tendency corresponds to the increase in amorphous structure estimated by Raman spectra. Argon ion bombardment results in constant hardness and fraction of amorphous structure. Argon ion beam bombardment of films prior to additional carbon deposition may cause the adhesion of the subsequently deposited films to improve. It is concluded that argon ion beam bombardment is useful for improving the properties of carbon films deposited onto WC and tool steels. (orig.).

Effects of ion beam bombardment of carbon thin films deposited onto tungsten carbide and tool steels

International Nuclear Information System (INIS)

Awazu, Kaoru; Yoshida, Hiroyuki; Watanabe, Hiroshi; Iwaki, Masaya; Guzman, L.

1992-01-01

A study was made of the effects of argon ion bombardment of carbon thin films deposited onto WC and tool steels. Carbon thin film deposition was performed at various temperatures ranging from 200degC to 350degC, using C 6 H 6 gas. Argon ion beam bombardment of the films was carried out at an energy of 150 keV with a dose of 1x10 16 ions cm -2 . The hardness and adhesion of the films were measured by means of Knoop hardness and scratch tests respectively. The structure of the carbon films was estimated by laser Raman spectroscopy, and the relations were investigated between the mechanical properties and the structure of the films. The hardness of carbon thin films increases as their deposition temperature decreases; this tendency corresponds to the increase in amorphous structure estimated by Raman spectra. Argon ion bombardment results in constant hardness and fraction of amorphous structure. Argon ion beam bombardment of films prior to additional carbon deposition may cause the adhesion of the subsequently deposited films to improve. It is concluded that argon ion beam bombardment is useful for improving the properties of carbon films deposited onto WC and tool steels. (orig.)

Properties of indium tin oxide films deposited on unheated polymer substrates by ion beam assisted deposition

International Nuclear Information System (INIS)

Yu Zhinong; Li Yuqiong; Xia Fan; Zhao Zhiwei; Xue Wei

2009-01-01

The optical, electrical and mechanical properties of indium tin oxide (ITO) films prepared on polyethylene terephthalate (PET) substrates by ion beam assisted deposition at room temperature were investigated. The properties of ITO films can be improved by introducing a buffer layer of silicon dioxide (SiO 2 ) between the ITO film and the PET substrate. ITO films deposited on SiO 2 -coated PET have better crystallinity, lower electrical resistivity, and improved resistance stability under bending than those deposited on bare PET. The average transmittance and the resistivity of ITO films deposited on SiO 2 -coated PET are 85% and 0.90 x 10 -3 Ω cm, respectively, and when the films are bent, the resistance remains almost constant until a bending radius of 1 cm and it increases slowly under a given bending radius with an increase of the bending cycles. The improved resistance stability of ITO films deposited on SiO 2 -coated PET is mainly attributed to the perfect adhesion of ITO films induced by the SiO 2 buffer layer.

Electrical performance of phase change memory cells with Ge3Sb2Te6 deposited by molecular beam epitaxy

International Nuclear Information System (INIS)

Boschker, Jos E.; Riechert, Henning; Calarco, Raffaella; Boniardi, Mattia; Redaelli, Andrea

2015-01-01

Here, we report on the electrical characterization of phase change memory cells containing a Ge 3 Sb 2 Te 6 (GST) alloy grown in its crystalline form by Molecular Beam Epitaxy (MBE). It is found that the high temperature growth on the amorphous substrate results in a polycrystalline film exhibiting a rough surface with a grain size of approximately 80–150 nm. A detailed electrical characterization has been performed, including I-V characteristic curves, programming curves, set operation performance, crystallization activation at low temperature, and resistance drift, in order to determine the material related parameters. The results indicate very good alignment of the electrical parameters with the current state-of-the-art GST, deposited by physical vapor deposition. Such alignment enables a possible employment of the MBE deposition technique for chalcogenide materials in the phase change memory technology, thus leading to future studies of as-deposited crystalline chalcogenides as integrated in electrical vehicles

Online diagnoses of high current-density beams

International Nuclear Information System (INIS)

Gilpatrick, J.D.

1994-01-01

Los Alamos National Laboratory has proposed several CW-proton-beam facilities for production of tritium or transmutation of nuclear waste with beam-current densities greater than 5 mA/mm 2 . The primary beam-diagnostics-instrumentation requirement for these facilities is provision of sufficient beam information to understand and minimize beam-loss. To accomplish this task, the beam-diagnostics instrumentation must measure beam parameters such as the centroids and profiles, total integrated current, and particle loss. Noninterceptive techniques must be used for diagnosis of high-intensity CW beam at low energies due to the large quantity of power deposited in an interceptive diagnostic device by the beam. Transverse and longitudinal centroid measurements have been developed for bunched beams by measuring and processing image currents on the accelerator walls. Transverse beam-profile measurement-techniques have also been developed using the interaction of the particle beam with the background gases near the beam region. This paper will discuss these noninterceptive diagnostic Techniques

SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

Science.gov (United States)

Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

2016-05-01

The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I-V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

Compositional analysis of YBaCuO superconducting films with ion beam analysis techniques

International Nuclear Information System (INIS)

Jones, S.; Timmers, H.; Ophel, T.R.; Elliman, R.G.

1999-01-01

High-T c YBa x Cu y O 7-δ superconducting films are being developed for applications such as superconducting quantum interference devices. The carrier concentration, critical current density J c and critical temperature T c of these films depend sensitively on the oxygen content . Stoichiometry, uniformity with depth, homogeneity across the sample and film thickness are also important quantities for their characterisation. It has been shown, for example, that the stoichiometry of the metallic elements affects the growth characteristics and surface morphology of the films. With the deposit ion techniques used, reproducibility of film properties is difficult. The characterisation of YBa x Cu y O 7-δ films with ion beam analysis techniques is complex. Whereas the three metallic elements can be detected with helium beams and Rutherford Backscattering (RBS), the oxygen signal is generally obscured by that from substrate elements. It can be better detected using resonant backscattering with 3.04MeV 4 He ions or nuclear reaction analysis. Elastic Recoil Detection (ERD) with high-energetic (1MeV/amu), heavy beams (Z > 120), enables all elements to be detected and separated in a single experiment. It is well established that ion bombardment induces vacancies in the oxygen sub-lattice, driving the material to change from crystalline to amorphous, the latter phase having a reduced oxygen content. In previous heavy ion ERD measurements of YBa x Cu yO z films with 200MeV 127 I beams, the opaque films became transparent in the beam spot area, indicative of the amorphous phase. The accuracy of the oxygen measurement is therefore questionable. Indeed, using Raman spectroscopy, distortions of the crystalline structure above a fluence of 5 x 10 11 ion/cm 2 and for higher doses some signatures of a reduction in oxygen content have been observed for such beams. It appears therefore that a correct determination of the oxygen content requires either a drastic reduction in fluence or a

Electron beam deposition system causing little damage to organic layers

Energy Technology Data Exchange (ETDEWEB)

Yamada, Minoru [Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Business Incubation Department, Hitachi Zosen Corporation, 2-11 Funamachi 2-Chome, Taisho-ku, Osaka 551-0022 (Japan); Matsumura, Michio, E-mail: matsu@chem.es.osaka-u.ac.jp [Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Maeda, Yasuhiro [Business Incubation Department, Hitachi Zosen Corporation, 2-11 Funamachi 2-Chome, Taisho-ku, Osaka 551-0022 (Japan)

2011-07-29

Conditions for deposition of an aluminum (Al) layer on an organic light-emitting layer with an electron beam (EB) deposition system were optimized with respect to deposition rate and damage to organic layers. The damage to the organic layers was found to be mostly caused by X-rays emitted from a target bombarded with accelerated electrons. In order to decrease the X-ray intensity while maintaining a high deposition rate, we used an EB source which emits high-density EB at low acceleration voltage. In addition, we inserted a heat reflector and a sintered-carbon liner between the Al target and copper crucible to improve heat insulation. As a result, the voltage needed for the deposition of Al electrodes at a rate of about 8 nm/s was lowered from normal voltages of 2.0 kV or higher to as low as 1.5 kV. To reduce the number of electrons hitting the substrate, we set pole pieces near the target and an electron trap in the chamber. The devices on which Al electrodes were deposited with the EB system showed almost the same properties as those of devices on which the Al electrodes were deposited by a resistive-heating method.

Titanium dioxide fine structures by RF magnetron sputter method deposited on an electron-beam resist mask

Science.gov (United States)

Hashiba, Hideomi; Miyazaki, Yuta; Matsushita, Sachiko

2013-09-01

Titanium dioxide (TiO2) has been draw attention for wide range of applications from photonic crystals for visible light range by its catalytic characteristics to tera-hertz range by its high refractive index. We present an experimental study of fabrication of fine structures of TiO2 with a ZEP electron beam resist mask followed by Ti sputter deposition techniques. A TiO2 thin layer of 150 nm thick was grown on an FTO glass substrate with a fine patterned ZEP resist mask by a conventional RF magnetron sputter method with Ti target. The deposition was carried out with argon-oxygen gases at a pressure of 5.0 x 10 -1 Pa in a chamber. During the deposition, ratio of Ar-O2 gas was kept to the ratio of 2:1 and the deposition ratio was around 0.5 Å/s to ensure enough oxygen to form TiO2 and low temperature to avoid deformation of fine pattern of the ZPU resist mask. Deposited TiO2 layers are white-transparent, amorphous, and those roughnesses are around 7 nm. Fabricated TiO2 PCs have wider TiO2 slabs of 112 nm width leaving periodic 410 x 410 nm2 air gaps. We also studied transformation of TiO2 layers and TiO2 fine structures by baking at 500 °C. XRD measurement for TiO2 shows that the amorphous TiO2 transforms to rutile and anatase forms by the baking while keeping the same profile of the fine structures. Our fabrication method can be one of a promising technique to optic devices on researches and industrial area.

Comparative study of tantalum deposition by chemical vapor deposition and electron beam vacuum evaporation

International Nuclear Information System (INIS)

Spitz, J.; Chevallier, J.

1975-01-01

The coating by tantalum of steel parts has been carried out by the two following methods: chemical vapor deposition by hydrogen reduction of TaCl 5 (temperature=1100 deg C, pressure=200 mmHg, H 2 /TaCl 5 =10); electron beam vacuum evaporation. In this case Ta was firstly condensed by ion plating (P(Ar)=5x10 -3 up to 2x10 -2 mmHg; U(c)=3 to -4kV and J(c)=0.2 to 1mAcm -2 ) in order to ensure a good adhesion between deposit and substrate; then by vacuum condensation (substrate temperature: 300 to 650 deg C) to ensure that the coating is impervious to HCl an H 2 SO 4 acids. The advantages and inconveniences of each method are discussed [fr

Thermal conductivity and nanocrystalline structure of platinum deposited by focused ion beam

KAUST Repository

Alaie, Seyedhamidreza; Goettler, Drew F.; Jiang, Yingbing; Abbas, Khawar; Baboly, Mohammadhosein Ghasemi; Anjum, Dalaver H.; Chaieb, Saharoui; Leseman, Zayd Chad

2015-01-01

Pt deposited by focused ion beam (FIB) is a common material used for attachment of nanosamples, repair of integrated circuits, and synthesis of nanostructures. Despite its common use little information is available on its thermal properties

Low-energy ion-beam deposition apparatus equipped with surface analysis system

International Nuclear Information System (INIS)

Ohno, Hideki; Aoki, Yasushi; Nagai, Siro.

1994-10-01

A sophisticated apparatus for low energy ion beam deposition (IBD) was installed at Takasaki Radiation Chemistry Research Establishment of JAERI in March 1991. The apparatus is composed of an IBD system and a real time/in-situ surface analysis system for diagnosing deposited thin films. The IBD system provides various kinds of low energy ion down to 10 eV with current density of 10 μA/cm 2 and irradiation area of 15x15 mm 2 . The surface analysis system consists of RHEED, AES, ISS and SIMS. This report describes the characteristics and the operation procedure of the apparatus together with some experimental results on depositing thin carbon films. (author)

Ion source for ion beam deposition employing a novel electrode assembly

Science.gov (United States)

Hayes, A. V.; Kanarov, V.; Yevtukhov, R.; Hegde, H.; Druz, B.; Yakovlevitch, D.; Cheesman, W.; Mirkov, V.

2000-02-01

A rf inductively coupled ion source employing a novel electrode assembly for focusing a broad ion beam on a relatively small target area was developed. The primary application of this ion source is the deposition of thin films used in the fabrication of magnetic sensors and optical devices. The ion optics consists of a three-electrode set of multiaperture concave dished grids with a beam extraction diameter of 150 mm. Also described is a variation in the design providing a beam extraction diameter of 120 mm. Grid hole diameters and grid spacing were optimized for low beamlet divergence and low grid impingement currents. The radius of curvature of the grids was optimized to obtain an optimally focused ion beam at the target location. A novel grid fabrication and mounting design was employed which overcomes typical limitations of such grid assemblies, particularly in terms of maintaining optimum beam focusing conditions after multiple cycles of operation. Ion beam generation with argon and xenon gases in energy ranges from 0.3 to 2.0 keV was characterized. For operation with argon gas, beam currents greater than 0.5 A were obtained with a beam energy of 800 eV. At optimal beam formation conditions, beam profiles at distances about equal to the radius of curvature were found to be close to Gaussian, with 99.9% of the beam current located within a 150 mm target diameter. Repeatability of the beam profile over long periods of operation is also reported.

Growth of Ge films by cluster beam deposition

CERN Document Server

Xu, J L; Feng, J Y

2002-01-01

Ge epitaxial layers with reasonable quality were grown on the Si(1 1 1) substrates by cluster beam deposition (CBD) process. The growth temperature plays a dominant role in the epitaxial growth of Ge films. The substrate temperature for epitaxial growth is about 500 deg. C, which is lower than the reported critical temperature of Ge epitaxial growth by MBE and CVD. A stress induced phase transition of Ge lattice from cubic to tetragonal is also observed in the CBD process, and the mechanism is discussed.

Charging effects during focused electron beam induced deposition of silicon oxide

NARCIS (Netherlands)

de Boer, Sanne K.; van Dorp, Willem F.; De Hosson, Jeff Th. M.

2011-01-01

This paper concentrates on focused electron beam induced deposition of silicon oxide. Silicon oxide pillars are written using 2, 4, 6, 8, 10-pentamethyl-cyclopenta-siloxane (PMCPS) as precursor. It is observed that branching of the pillar occurs above a minimum pillar height. The branching is

Room-Temperature Growth of SiC Thin Films by Dual-Ion-Beam Sputtering Deposition

Directory of Open Access Journals (Sweden)

C. G. Jin

2008-01-01

Full Text Available Silicon carbide (SiC films were prepared by single and dual-ion-beamsputtering deposition at room temperature. An assisted Ar+ ion beam (ion energy Ei = 150 eV was directed to bombard the substrate surface to be helpful for forming SiC films. The microstructure and optical properties of nonirradicated and assisted ion-beam irradicated films have been characterized by transmission electron microscopy (TEM, scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, and Raman spectra. TEM result shows that the films are amorphous. The films exposed to a low-energy assisted ion-beam irradicated during sputtering from a-SiC target have exhibited smoother and compacter surface topography than which deposited with nonirradicated. The ion-beam irradicated improves the adhesion between film and substrate and releases the stress between film and substrate. With assisted ion-beam irradicated, the density of the Si–C bond in the film has increased. At the same time, the excess C atoms or the size of the sp2 bonded clusters reduces, and the a-Si phase decreases. These results indicate that the composition of the film is mainly Si–C bond.

Tool steel ion beam assisted nitrocarburization

International Nuclear Information System (INIS)

Zagonel, L.F.; Alvarez, F.

2007-01-01

The nitrocarburization of the AISI-H13 tool steel by ion beam assisted deposition is reported. In this technique, a carbon film is continuously deposited over the sample by the ion beam sputtering of a carbon target while a second ion source is used to bombard the sample with low energy nitrogen ions. The results show that the presence of carbon has an important impact on the crystalline and microstructural properties of the material without modification of the case depth

Friction of self-lubricating surfaces by ion beam techniques. Final technical report

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, R.S.; Rai, A.K.

1992-05-01

UES, Inc. conducted a research and development program designed to establish conditions for ion implantation/mixing of suitable additives into the surfaces of bulk ceramics and metals for obtaining self-lubricating low friction and wear characteristics. The substrates considered were ZrO{sub 2}, Al{sub 2}O{sub 3}, Si{sub 3}N{sub 4}, steel and Ni-base superalloy. The lubricant additives chosen were BaF{sub 2}/CaF{sub 2}Ag, MoS{sub 2}, WS{sub 2}and B{sub 2}O{sub 3}. The initial tasks of the program were to synthesis these lubricant compounds by co-implantation of constituent elements if sufficient beams of desired elements were obtained. The final tasks were to investigate high energy (MeV) ion mixing of deposited coatings as well as to investigate ion beam assisted deposition using low energy ion beams. It was shown that MoS{sub 2} can be synthesized by co-implantation of Mo{sup +} and S{sup +} in ceramic materials with appropriate choice of energies to obtain nearly overlapping depth profiles. The sliding life of DC magnetron sputtered MoS{sub 2} films of thicknesses {approximately}7500{Angstrom} on ceramic materials such as sapphire, Si{sub 3}N{sub 4} and ZrO{sub 3} were improved by ten to thousand fold after 2 Mev Ag{sup +} ion mixing. Ion beam assisted deposition (IBAD) and ion beam mixing were utilized to fabricate self-lubricating coatings of CaF{sub 2}/Ag and BaF/CaF{sub 2}/Ag composites.

The Impact of Beam Deposition on Bootstrap Current of Fast Ion Produced by Neutral Beam Tangential Injection

International Nuclear Information System (INIS)

Huang Qian-Hong; Gong Xue-Yu; Lu Xing-Qiang; Yu Jun; Cao Jin-Jia

2015-01-01

The density profile of fast ions arising from a tangentially injected diffuse neutral beam in tokamak plasma is calculated. The effects of mean free paths and beam tangency radius on the density profile are discussed under typical HL-2A plasmas parameters. The results show that the profile of fast ions is strongly peaked at the center of the plasma when the mean free path at the maximum deuteron density is larger than the minor radius, while the peak value decreases when the mean free path at the maximum deuteron density is larger than twice that of the minor radius due to the beam transmission loss. Moreover, the bootstrap current of fast ions for various mean free paths at the maximum deuteron density is calculated and its density is proved to be closely related to the deposition of the neutral beam. With the electron return current considered, the net current density obviously decreases. Meanwhile, the peak central fast ion density increases when the beam tangency radius approaches the major radius, and the net bootstrap current increases rapidly with the increasing beam tangency radius. (paper)

Molecule-by-Molecule Writing Using a Focused Electron Beam

DEFF Research Database (Denmark)

Van Dorp, Willem F.; Zhang, Xiaoyan; Feringa, Ben L.

2012-01-01

atoms also be written with an electron beam? We verify this with focused electron-beam-induced deposition (FEBID), a direct-write technique that has the current record for the smallest feature written by (electron) optical lithography. We show that the deposition of an organometallic precursor...... on graphene can be followed molecule-by-molecule with FEBID. The results show that mechanisms that are inherent to the process inhibit a further increase in control over the process. Hence, our results present the resolution limit of (electron) optical lithography techniques. The writing of isolated...

Beam dynamics in rf guns and emittance correction techniques

International Nuclear Information System (INIS)

Serafini, L.

1994-01-01

In this paper we present a general review of beam dynamics in a laser-driven rf gun. The peculiarity of such an accelerating structure versus other conventional multi-cell linac structures is underlined on the basis of the Panofsky-Wenzel theorem, which is found to give a theoretical background for the well known Kim's model. A basic explanation for some proposed methods to correct rf induced emittance growth is also derived from the theorem. We also present three emittance correction techniques for the recovery of space-charge induced emittance growth, namely the optimum distributed disk-like bunch technique, the use of rf spatial harmonics to correct spherical aberration induced by space charge forces and the technique of emittance filtering by clipping the electron beam. The expected performances regarding the beam quality achievable with different techniques, as predicted by scaling laws and simulations, are analyzed, and, where available, compared to experimental results. (orig.)

The electron beam deposition of titanium on polyetheretherketone (PEEK) and the resulting enhanced biological properties.

Science.gov (United States)

Han, Cheol-Min; Lee, Eun-Jung; Kim, Hyoun-Ee; Koh, Young-Hag; Kim, Keung N; Ha, Yoon; Kuh, Sung-Uk

2010-05-01

The surface of polyetheretherketone (PEEK) was coated with a pure titanium (Ti) layer using an electron beam (e-beam) deposition method in order to enhance its biocompatibility and adhesion to bone tissue. The e-beam deposition method was a low-temperature coating process that formed a dense, uniform and well crystallized Ti layer without deteriorating the characteristics of the PEEK implant. The Ti coating layer strongly adhered to the substrate and remarkably enhanced its wettability. The Ti-coated samples were evaluated in terms of their in vitro cellular behaviors and in vivo osteointegration, and the results were compared to a pure PEEK substrate. The level of proliferation of the cells (MC3T3-E1) was measured using a methoxyphenyl tetrazolium salt (MTS) assay and more than doubled after the Ti coating. The differentiation level of cells was measured using the alkaline phosphatase (ALP) assay and also doubled. Furthermore, the in vivo animal tests showed that the Ti-coated PEEK implants had a much higher bone-in-contact (BIC) ratio than the pure PEEK implants. These in vitro and in vivo results suggested that the e-beam deposited Ti coating significantly improved the potential of PEEK for hard tissue applications. Copyright 2009 Elsevier Ltd. All rights reserved.

Reduction of deposition asymmetries in directly driven ion-beam and laser targets

International Nuclear Information System (INIS)

Mark, J.W.K.

1985-01-01

The authors have developed a procedure for reducing energy-dependent asymmetry in spherical targets driven directly by ion or laser beams. This work is part of a strategy for achieving illumination symmetry in such targets, which they propose as an alternative to those in the literature. This strategy allows an axially symmetric placement of beamlets, which would be convenient for some driver or reactor scenarios. It also allows the use of beam currents or energy fluxes to help reduce deposition asymmetry

Novel non-intercepting diagnostic techniques for low-emittance relativistic electron beams

International Nuclear Information System (INIS)

Moran, M.J.; Chang, B.

1988-01-01

Relativistic electron beams are being generated with emittances low enough that diffraction radiation can be used for beam diagnostics. Techniques based on diffraction radiation can be used to measure the beam transverse momentum distribution and to measure the transverse spatial distribution. The radiation is intense and can be in the visible spectral region where optical diagnostic techniques can be used to maximum advantage. 4 refs. 3 figs

Biomaterial thin film deposition and characterization by means of MAPLE technique

International Nuclear Information System (INIS)

Bloisi, F.; Vicari, L.; Papa, R.; Califano, V.; Pedrazzani, R.; Bontempi, E.; Depero, L.E.

2007-01-01

Polyethylene glycol (PEG) is a polymer with technologically important applications, especially as a biomaterial. Several biomedical applications (such as tissue engineering, spatial patterning of cells, anti-biofouling and biocompatible coatings) require the application of high quality PEG thin films. In order to have a good adhesion to substrate chemically modified polymer molecules have been used, but for some 'in vivo' applications it is essential to deposit a film with the same chemical and structural properties of bulk PEG. Pulsed laser deposition (PLD) technique is generally able to produce high quality thin films but it is inadequate for polymer/organic molecules. MAPLE (Matrix Assisted Pulsed Laser Evaporation) is a recently developed PLD based thin film deposition technique, particularly well suited for organic/polymer thin film deposition. Up to now MAPLE depositions have been carried out mainly by means of modified PLD systems, using excimer lasers operating in UV, but the use of less energetic radiations can minimize the photochemical decomposition of the polymer molecules. We have used a deposition system explicitly designed for MAPLE technique connected to a Q-switched Ng:YAG pulsed laser which can be operated at different wavelength ranging from IR to UV in order to optimise the deposition parameters. The capability of MAPLE technique to deposit PEG has been confirmed and preliminary results show that visible (532 nm wavelength) radiation gives better results with respect to UV (355 nm) radiation. Despite usually UV wavelengths have been used and even if more systematic tests must be performed, it is important to underline that the choice of laser wavelength plays an important role in the application of MAPLE thin film deposition technique

Characteristics of thin film fullerene coatings formed under different deposition conditions by power ion beams

International Nuclear Information System (INIS)

Petrov, A.V.; Ryabchikov, A.I.; Struts, V.K.; Usov, Yu.P.; Renk, T.J.

2007-01-01

Carbon allotropic form - C 60 and C 70 can be used in microelectronics, superconductors, solar batteries, logic and memory devices to increase processing tool wear resistance, as magnetic nanocomposite materials for record and storage information, in biology, medicine and pharmacology. In many cases it is necessary to have a thin-film containing C 60 and C 70 fullerene carbon coatings. A possibility in principle of thin carbon films formation with nanocrystalline structure and high content ∼30-95% of C 60 and C 70 fullerene mixture using the method of graphite targets sputtering by a power ion beam has been shown. Formation of thin-film containing C 60 and C 70 fullerene carbon coatings were carried out by means of deposition of ablation plasma on silicon substrates. Ablation plasma was generated as result of interaction of high-power pulsed ion beams (HPPIB) with graphite targets of different densities. It has been demonstrated that formation of fullerenes, their amount and characteristics of thin-film coatings depend on the deposition conditions. The key parameter for such process is the deposition rate, which determines thin film formation conditions and, subsequently, its structure and mechanical properties. Nano-hardness, Young module, adhesion to mono-crystalline silicon substrate, friction coefficient, roughness surface of synthesized coatings at the different deposition conditions were measured. These characteristics are under influence of such main process parameters as energy density of HPPIB, which, in turn, determinates the density and temperature of ablation plasma and deposition speed, which is thickness of film deposited for one pulse of ion current. Nano-hardness and Young module meanings are higher at the increasing of power density of ion beam. Adhesion value is less at the high deposition speed. As rule, friction coefficient depends on vice versa from roughness. (authors)

Process-structure-property relationships of micron thick gadolinium oxide films deposited by reactive electron beam-physical vapor deposition (EB-PVD)

Science.gov (United States)

Grave, Daniel A.

Gadolinium oxide (Gd2O3) is an attractive material for solid state neutron detection due to gadolinium's high thermal neutron capture cross section. Development of neutron detectors based on Gd2 O3 requires sufficiently thick films to ensure neutron absorption. In this dissertation work, the process-structure-property relationships of micron thick Gd2O3 films deposited by reactive electron-beam physical vapor deposition (EB-PVD) were studied. Through a systematic design of experiments, fundamental studies were conducted to determine the effects of processing conditions such as deposition temperature, oxygen flow rate, deposition rate, and substrate material on Gd2O3 film crystallographic phase, texture, morphology, grain size, density, and surface roughness. Films deposited at high rates (> 5 A/s) were examined via x-ray diffraction (XRD) and Raman spectroscopy. Quantitative phase volume calculations were performed via a Rietveld refinement technique. All films deposited at high rates were found to be fully monoclinic or mixed cubic/monoclinic phase. Generally, increased deposition temperature and increased oxygen flow resulted in increased cubic phase volume. As film thickness increased, monoclinic phase volume increased. Grazing incidence x-ray diffraction (GIXRD) depth profiling analysis showed that cubic phase was only present under large incidence angle (large penetration depth) measurements, and after a certain point, only monoclinic phase was grown. This was confirmed by transmission electron microscopy (TEM) analysis with selected area diffraction (SAD). Based on this information, a large compressive stress was hypothesized to cause the formation of the monoclinic phase and this hypothesis was confirmed by demonstrating the existence of a stress induced phase transition. An experiment was designed to introduce compressive stress into the Gd2O 3 films via ion beam assisted deposition (IBAD). This allowed for systematic increase in compressive stress while

Laser chemical vapor deposition of millimeter scale three-dimensional shapes

Science.gov (United States)

Shaarawi, Mohammed Saad

2001-07-01

Laser chemical vapor deposition (LCVD) has been successfully developed as a technique to synthesize millimeter-scale components directly from the gas phase. Material deposition occurs when heat generated by the interaction of a laser beam with a substrate thermally decomposes the gas precursor. Selective illumination or scanning the laser beam over portions of a substrate forms the single thin layer of material that is the building block of this process. Sequential scanning of the laser in a pre-defined pattern on the substrate and subsequent deposit causes the layers to accumulate forming the three-dimensional shape. The primary challenge encountered in LCVD shape forming is the synthesis of uniform layers. Three deposition techniques are studied to address this problem. The most successful technique, Active Surface Deposition, is based on the premise that the most uniform deposits are created by measuring the deposition surface topology and actively varying the deposition rate in response to features at the deposition surface. Defects observed in the other techniques were significantly reduced or completely eliminated using Active Surface Deposition. The second technique, Constant Temperature Deposition, maintains deposit uniformity through the use of closed-loop modulation of the laser power to sustain a constant surface temperature during deposition. The technique was successful in depositing high quality graphite tubes >2 mm tall from an acetylene precursor and partially successful in depositing SiC + C composite tubes from tetramethylsilane (TMS). The final technique, Constant Power Deposition, is based on the premise that maintaining a uniform power output throughout deposition would result in the formation of uniform layers. Constant Power Deposition failed to form coherent shapes. Additionally, LCVD is studied using a combination of analytic and numerical models to gain insight into the deposition process. Thermodynamic modeling is used to predict the

Improvement of the inlet system for the spray-jet technique for use in spectroscopic studies and molecular deposition

International Nuclear Information System (INIS)

Yamada, Toshiki; Shinohara, Hidenori; Mashiko, Shinro

2006-01-01

We previously developed a molecular beam apparatus with a spray-jet technique in order to produce a molecular beam of non-volatile molecules in vacuum from the sprayed mist of a sample solution. The apparatus is for use in spectroscopic studies or a means of molecular deposition. The spray-jet inlet system consisted of an ultrasonic nebulizer, an inlet chamber and a pulsed nozzle. In the present paper, further improvements to the spray-jet inlet system are reported. The main improvement is the introduction of a pneumatic nebulizer to replace the previous ultrasonic nebulizer. The efficiency of molecular beam generation was evaluated on the basis of the signal intensity of the resonantly enhanced multiphoton ionization time-of-flight mass (REMPI-TOFMS) spectra for a Rhodamine B/methanol solution and the amount of sample consumed. The introduction of the pneumatic nebulizer increased the efficiency by a factor of 20

Energy deposition of heavy ions in the regime of strong beam-plasma correlations.

Science.gov (United States)

Gericke, D O; Schlanges, M

2003-03-01

The energy loss of highly charged ions in dense plasmas is investigated. The applied model includes strong beam-plasma correlation via a quantum T-matrix treatment of the cross sections. Dynamic screening effects are modeled by using a Debye-like potential with a velocity dependent screening length that guarantees the known low and high beam velocity limits. It is shown that this phenomenological model is in good agreement with simulation data up to very high beam-plasma coupling. An analysis of the stopping process shows considerably longer ranges and a less localized energy deposition if strong coupling is treated properly.

POLYMER COMPOSITE FILMS WITH SIZE-SELECTED METAL NANOPARTICLES FABRICATED BY CLUSTER BEAM TECHNIQUE

DEFF Research Database (Denmark)

Ceynowa, F. A.; Chirumamilla, Manohar; Popok, Vladimir

2017-01-01

Formation of polymer films with size-selected silver and copper nanoparticles (NPs) is studied. Polymers are prepared by spin coating while NPs are fabricated and deposited utilizing a magnetron sputtering cluster apparatus. The particle embedding into the films is provided by thermal annealing...... after the deposition. The degree of immersion can be controlled by the annealing temperature and time. Together with control of cluster coverage the described approach represents an efficient method for the synthesis of thin polymer composite layers with either partially or fully embedded metal NPs....... Combining electron beam lithography, cluster beam deposition and thermal annealing allows to form ordered arrays of metal NPs on polymer films. Plasticity and flexibility of polymer host and specific properties added by coinage metal NPs open a way for different applications of such composite materials...

Development of an ion-beam sputtering system for depositing thin films and multilayers of alloys and compounds

International Nuclear Information System (INIS)

Gupta, Mukul; Gupta, Ajay; Phase, D.M.; Chaudhari, S.M.; Dasannacharya, B.A.

2002-01-01

An ion-beam sputtering (IBS) system has been designed and developed for preparing thin films and multilayers of various elements, alloys and compounds. The ion source used is a 3 cm diameter, hot-cathode Kaufman type 1.5 kV ion source. The system has been successfully tested with the deposition of various materials, and the deposition parameters were optimised for achieving good quality of thin films and multilayers. A systematic illustration of the versatility of the system to produce a variety of structures is done by depositing thin film of pure iron, an alloy film of Fe-Zr, a compound thin film of FeN, a multilayer of Fe-Ag and an isotopic multilayer of 57 FeZr/FeZr. Microstructural measurements on these films using X-ray and neutron reflectivity, atomic force microscopy (AFM), and X-ray diffraction are presented and discussed to reveal the quality of the microstructures obtained with the system. It is found that in general, the surface roughnesses of the film deposited by IBS are significantly smaller as compared to those for films deposited by e-beam evaporation. Further, the grain size of the IBS crystalline films is significantly refined as compared to the films deposited by e-beam evaporation. Grain refinement may be one of the reasons for reduced surface roughness. In the case of amorphous films, the roughness of the films does not increase appreciably beyond that of the substrate even after depositing thicknesses of several hundred angstroms

Effect of laser beam parameters on magnetic properties of Nd-Fe-B thick-film magnets fabricated by pulsed laser deposition

International Nuclear Information System (INIS)

Fukunaga, H.; Nakano, M.; Yanai, T.; Kamikawatoko, T.; Yamashita, F.

2011-01-01

The effects of varying the laser power and the spot diameter of a laser beam on the magnetic properties, morphology, and deposition rate of Nd-Fe-B thick-film magnets fabricated by pulsed laser deposition (PLD) were investigated. Reducing the laser fluence on the target reduces the remanence and increases the Nd content and consequently the coercivity of the prepared films. The spot size of the laser beam was found to affect the film surface morphology, the deposition rate, and the reproducibility of the magnetic properties of the prepared films. Reducing the spot size reduces the number of droplets and the reproducibility of the magnetic properties and increases the droplet size. Controlling the spot size of the laser beam enabled us to maximize the deposition rate. Consequently, a coercivity of 1210 kA/m and a remanence of 0.51 T were obtained at a deposition rate of 11.8 μm/(h·W). This deposition rate is 30% greater than the highest previously reported deposition rate by PLD.

Radioactive ion beams and techniques for solid state research

International Nuclear Information System (INIS)

Correia, J.G.

1998-01-01

In this paper we review the most recent and new applications of solid state characterization techniques using radioactive ion beams. For such type ofresearch, high yields of chemically clean ion beams of radioactive isotopesare needed which are provided by the on-line coupling of high resolution isotope separators to particle accelerators, such as the isotope separator on-line (ISOLDE) facility at CERN. These new experiments are performed by an increasing number of solid state groups. They combine nuclear spectroscopic techniques such as Moessbauer, perturbed angular correlations (PAC) and emission channeling with the traditional non-radioactive techniques liked deep level transient spectroscopy (DLTS) and Hall effect measurements. Recently isotopes of elements, not available before, were successfully used in new PAC experiments, and the first photoluminescence (PL) measurements, where the element transmutation plays the essential role on the PL peak identification, have been performed. The scope of applications of radioactive ion beams for research in solid state physics will be enlarged in the near future, with the installation at ISOLDE of a post-accelerator device providing radioactive beams with energies ranging from a few keV up to a few MeV. (orig.)

Thermionic vacuum arc (TVA) technique for magnesium thin film deposition

Energy Technology Data Exchange (ETDEWEB)

Balbag, M.Z., E-mail: zbalbag@ogu.edu.t [Eskisehir Osmangazi University, Education Faculty, Primary Education, Meselik Campus, Eskisehir 26480 (Turkey); Pat, S.; Ozkan, M.; Ekem, N. [Eskisehir Osmangazi University, Art and Science Faculty, Physics Department, Eskisehir 26480 (Turkey); Musa, G. [Ovidius University, Physics Department, Constanta (Romania)

2010-08-15

In this study, magnesium thin films were deposited on glass substrate by the Thermionic Vacuum Arc (TVA) technique for the first time. We present a different technique for deposition of high-quality magnesium thin films. By means of this technique, the production of films is achieved by condensing the plasma of anode material generated using Thermionic Vacuum Arc (TVA) under high vacuum conditions onto the surface to be coated. The crystal orientation and morphology of the deposited films were investigated by using XRD, EDX, SEM and AFM. The aim of this study is to search the use of TVA technique to coat magnesium thin films and to determine some of the physical properties of the films generated. Furthermore, this study will contribute to the scientific studies which search the thin films of magnesium or the compounds containing magnesium. In future, this study will be preliminary work to entirely produce magnesium diboride (MgB{sub 2}) superconductor thin film with the TVA technique.

CoPt nanoparticles deposited by electron beam evaporation

International Nuclear Information System (INIS)

Castaldi, L.; Giannakopoulos, K.; Travlos, A.; Niarchos, D.; Boukari, S.; Beaurepaire, E.

2005-01-01

Co 50 Pt 50 nanoparticles were co-deposited on thermally oxidized Si substrates by electron beam evaporation at 750 deg C. The mean particle sizes are between ∼5 and ∼20 nm and depend on the nominal thickness of the layer. Different processing conditions resulted in different structural and morphological properties of the samples which led to superparamagnetic and ferromagnetic behaviors. The post-annealing treatment of the CoPt nanograins resulted in the crystallization of the L1 0 ordered phase and in the magnetic hardening of nanoparticles with a maximum coercivity of ∼7.4 kOe

Applying field mapping refractive beam shapers to improve holographic techniques

Science.gov (United States)

Laskin, Alexander; Williams, Gavin; McWilliam, Richard; Laskin, Vadim

2012-03-01

Performance of various holographic techniques can be essentially improved by homogenizing the intensity profile of the laser beam with using beam shaping optics, for example, the achromatic field mapping refractive beam shapers like πShaper. The operational principle of these devices presumes transformation of laser beam intensity from Gaussian to flattop one with high flatness of output wavefront, saving of beam consistency, providing collimated output beam of low divergence, high transmittance, extended depth of field, negligible residual wave aberration, and achromatic design provides capability to work with several laser sources with different wavelengths simultaneously. Applying of these beam shapers brings serious benefits to the Spatial Light Modulator based techniques like Computer Generated Holography or Dot-Matrix mastering of security holograms since uniform illumination of an SLM allows simplifying mathematical calculations and increasing predictability and reliability of the imaging results. Another example is multicolour Denisyuk holography when the achromatic πShaper provides uniform illumination of a field at various wavelengths simultaneously. This paper will describe some design basics of the field mapping refractive beam shapers and optical layouts of their applying in holographic systems. Examples of real implementations and experimental results will be presented as well.

Five second helium neutral beam injection using argon-frost cryopumping techniques

International Nuclear Information System (INIS)

Phillips, J.C.; Kellman, D.H.; Hong, R.; Kim, J.; Laughon, G.M.

1995-10-01

High power helium neutral beams for the heating of tokamak discharges can now be provided for 5 s by using argon cryopumping (of the helium gas) in the beamlines. A system has now been installed to deposit a layer of argon frost on the DIII-D neutral beam cryopanels, between tokamak injection pulses. The layer serves to trap helium on the cryopanels providing sufficient pumping speed for 5 s helium beam extraction. The argon frosting hardware is now present on two of four DIII-D neutral beamlines, allowing injection of up to 6 MW of helium neutral beams per discharge, with pulse lengths of up to 5 s. The argon frosting system is described, along with experimental results demonstrating its effectiveness as a method of economically extending the capabilities of cryogenic pumping panels to allow multi-second helium neutral beam injection

Technology and applications of broad-beam ion sources used in sputtering. Part II. Applications

International Nuclear Information System (INIS)

Harper, J.M.E.; Cuomo, J.J.; Kaufman, H.R.

1982-01-01

The developments in broad-beam ion source technology described in the companion paper (Part I) have stimulated a rapid expansion in applications to materials processing. These applications are reviewed here, beginning with a summary of sputtering mechanisms. Next, etching applications are described, including microfabrication and reactive ion beam etching. The developing area of surface layer applications is summarized, and related to the existing fields of oxidation and implantation. Next, deposition applications are reviewed, including ion-beam sputter deposition and the emerging technique of ion-assisted vapor deposition. Many of these applications have been stimulated by the development of high current ion sources operating in the energy range of tens of hundreds of eV. It is in this energy range that ion-activated chemical etching is efficient, self-limiting compound layers can be grown, and the physical properties of vapor-deposited films can be modified. In each of these areas, broad ion beam technology provides a link between other large area plasma processes and surface analytical techniques using ion beams

Ion beam deposition system for depositing low defect density extreme ultraviolet mask blanks

Science.gov (United States)

Jindal, V.; Kearney, P.; Sohn, J.; Harris-Jones, J.; John, A.; Godwin, M.; Antohe, A.; Teki, R.; Ma, A.; Goodwin, F.; Weaver, A.; Teora, P.

2012-03-01

Extreme ultraviolet lithography (EUVL) is the leading next-generation lithography (NGL) technology to succeed optical lithography at the 22 nm node and beyond. EUVL requires a low defect density reflective mask blank, which is considered to be one of the top two critical technology gaps for commercialization of the technology. At the SEMATECH Mask Blank Development Center (MBDC), research on defect reduction in EUV mask blanks is being pursued using the Veeco Nexus deposition tool. The defect performance of this tool is one of the factors limiting the availability of defect-free EUVL mask blanks. SEMATECH identified the key components in the ion beam deposition system that is currently impeding the reduction of defect density and the yield of EUV mask blanks. SEMATECH's current research is focused on in-house tool components to reduce their contributions to mask blank defects. SEMATECH is also working closely with the supplier to incorporate this learning into a next-generation deposition tool. This paper will describe requirements for the next-generation tool that are essential to realize low defect density EUV mask blanks. The goal of our work is to enable model-based predictions of defect performance and defect improvement for targeted process improvement and component learning to feed into the new deposition tool design. This paper will also highlight the defect reduction resulting from process improvements and the restrictions inherent in the current tool geometry and components that are an impediment to meeting HVM quality EUV mask blanks will be outlined.

Techniques for intense-proton-beam profile measurements

International Nuclear Information System (INIS)

Gilpatrick, J.D.

1998-01-01

In a collaborative effort with industry and several national laboratories, the Accelerator Production of Tritium (APT) facility and the Spallation Neutron Source (SNS) linac are presently being designed and developed at Los Alamos National Laboratory (LANL). The APT facility is planned to accelerate a 100-mA H + cw beam to 1.7 GeV and the SNS linac is planned to accelerate a 1- to 4-mA-average, H - , pulsed-beam to 1 GeV. With typical rms beam widths of 1- to 3-mm throughout much of these accelerators, the maximum average-power densities of these beams are expected to be approximately 30- and 1-MW-per-square millimeter, respectively. Such power densities are too large to use standard interceptive techniques typically used for acquisition of beam profile information. This paper summarizes the specific requirements for the beam profile measurements to be used in the APT, SNS, and the Low Energy Development Accelerator (LEDA)--a facility to verify the operation of the first 20-MeV section of APT. This paper also discusses the variety of profile measurement choices discussed at a recent high-average-current beam profile workshop held in Santa Fe, NM, and will present the present state of the design for the beam profile measurements planned for APT, SNS, and LEDA

Magnetic filtered plasma deposition and implantation technique

CERN Document Server

Zhang Hui Xing; Wu Xian Ying

2002-01-01

A high dense metal plasma can be produced by using cathodic vacuum arc discharge technique. The microparticles emitted from the cathode in the metal plasma can be removed when the metal plasma passes through the magnetic filter. It is a new technique for making high quality, fine and close thin films which have very widespread applications. The authors describe the applications of cathodic vacuum arc technique, and then a filtered plasma deposition and ion implantation system as well as its applications

Electronic properties of single Ge/Si quantum dot grown by ion beam sputtering deposition.

Science.gov (United States)

Wang, C; Ke, S Y; Yang, J; Hu, W D; Qiu, F; Wang, R F; Yang, Y

2015-03-13

The dependence of the electronic properties of a single Ge/Si quantum dot (QD) grown by the ion-beam sputtering deposition technique on growth temperature and QD diameter is investigated by conductive atomic force microscopy (CAFM). The Si-Ge intermixing effect is demonstrated to be important for the current distribution of single QDs. The current staircase induced by the Coulomb blockade effect is observed at higher growth temperatures (>700 °C) due to the formation of an additional barrier between dislocated QDs and Si substrate for the resonant tunneling of holes. According to the proposed single-hole-tunneling model, the fact that the intermixing effect is observed to increase as the incoherent QD size decreases may explain the increase in the starting voltage of the current staircase and the decrease in the current step width.

Understanding the electron-stimulated surface reactions of organometallic complexes to enable design of precursors for electron beam-induced deposition

Energy Technology Data Exchange (ETDEWEB)

Spencer, Julie A.; Rosenberg, Samantha G.; Barclay, Michael; Fairbrother, D. Howard [Johns Hopkins University, Department of Chemistry, Baltimore, MD (United States); Wu, Yung-Chien; McElwee-White, Lisa [University of Florida, Department of Chemistry, Gainesville, FL (United States)

2014-12-15

Standard practice in electron beam-induced deposition (EBID) is to use precursors designed for thermal processes, such as chemical vapor deposition (CVD). However, organometallic precursors that yield pure metal deposits in CVD often create EBID deposits with high levels of organic contamination. This contamination negatively impacts the deposit's properties (e.g., by increasing resistivity or decreasing catalytic activity) and severely limits the range of potential applications for metal-containing EBID nanostructures. To provide the information needed for the rational design of precursors specifically for EBID, we have employed an ultra-high vacuum (UHV) surface science approach to identify the elementary reactions of organometallic precursors during EBID. These UHV studies have demonstrated that the initial electron-induced deposition of the surface-bound organometallic precursors proceeds through desorption of one or more of the ligands present in the parent compound. In specific cases, this deposition step has been shown to proceed via dissociative electron attachment, involving low-energy secondary electrons generated by the interaction of the primary beam with the substrate. Electron beam processing of the surface-bound species produced in the initial deposition event usually causes decomposition of the residual ligands, creating nonvolatile fragments. This process is believed to be responsible for a significant fraction of the organic contaminants typically observed in EBID nanostructures. A few ligands (e.g., halogens) can, however, desorb during electron beam processing while other ligands (e.g., PF{sub 3}, CO) can thermally desorb if elevated substrate temperatures are used during deposition. Using these general guidelines for reactivity, we propose some design strategies for EBID precursors. The ultimate goal is to minimize organic contamination and thus overcome the key bottleneck for fabrication of relatively pure EBID nanostructures. (orig.)

Progress on channel spark development and application of pulsed electron beam deposition (PED) in the field of medical coating work

International Nuclear Information System (INIS)

Schultheiss, Christoph; Buth, Lothar-H.-O.; Frey, Wolfgang; Bluhm, Hansjoachim; Mayer, Hanns-G.

2002-01-01

A promising source for Pulsed Electron Beam Deposition (PED) is the channel spark. Recent improvements helped to reduce beam instabilities which up to now have limited the life time of the system. The beam power could be increased and because of better beam quality the transport length of the beam is increased from 1 to several centimeters (up to 10 cm). Together with other improvements on the triggering system and beam transport in dielectric tubes, the channel spark approaches industrial standards. An overview of actual applications in research and industry will be presented. An attractive feature of the pulsed electron beam thin film deposition is the conservation of stoichiometry even during deposition of multi-component earth-alkali and alkali glasses. Specially developed glasses like BIOGLAS registered have the ability to anchor soft living tissue at the surface. In form of a bulk material bio active glasses are brittle limiting its applications. Contrary to brittle bulk material a thin layers on medical implants exhibits reliable bio-functionality. Coating of implants with this category of materials is subject of the European INCOMED project (Innovative Coating of Medical Implants with Soft Tissue Anchoring Ability) which just has started

Energy deposition, heat flow, and rapid solidification during laser and electron beam irradiation of materials

Energy Technology Data Exchange (ETDEWEB)

White, C.W.; Aziz, M.J.

1985-10-01

The fundamentals of energy deposition, heat flow, and rapid solidification during energy deposition from lasers and electron beams is reviewed. Emphasis is placed on the deposition of energy from pulsed sources (10 to 100 ns pulse duration time) in order to achieve high heating and cooling rates (10/sup 8/ to 10/sup 10/ /sup 0/C/s) in the near surface region. The response of both metals and semiconductors to pulsed energy deposition is considered. Guidelines are presented for the choice of energy source, wavelength, and pulse duration time.

Biosensor Applications of MAPLE Deposited Lipase

Directory of Open Access Journals (Sweden)

Valeria Califano

2014-10-01

Full Text Available Matrix Assisted Pulsed Laser Evaporation (MAPLE is a thin film deposition technique derived from Pulsed Laser Deposition (PLD for deposition of delicate (polymers, complex biological molecules, etc. materials in undamaged form. The main difference of MAPLE technique with respect to PLD is the target: it is a frozen solution or suspension of the (guest molecules to be deposited in a volatile substance (matrix. Since laser beam energy is mainly absorbed by the matrix, damages to the delicate guest molecules are avoided, or at least reduced. Lipase, an enzyme catalyzing reactions borne by triglycerides, has been used in biosensors for detection of β-hydroxyacid esters and triglycerides in blood serum. Enzymes immobilization on a substrate is therefore required. In this paper we show that it is possible, using MAPLE technique, to deposit lipase on a substrate, as shown by AFM observation, preserving its conformational structure, as shown by FTIR analysis.

XPS study of the ultrathin a-C:H films deposited onto ion beam nitrided AISI 316 steel

International Nuclear Information System (INIS)

Meskinis, S.; Andrulevicius, M.; Kopustinskas, V.; Tamulevicius, S.

2005-01-01

Effects of the steel surface treatment by nitrogen ion beam and subsequent deposition of the diamond-like carbon (hydrogenated amorphous carbon (a-C:H) and nitrogen doped hydrogenated amorphous carbon (a-CN x :H)) films were investigated by means of the X-ray photoelectron spectroscopy (XPS). Experimental results show that nitrogen ion beam treatment of the AISI 316 steel surface even at room temperature results in the formation of the Cr and Fe nitrides. Replacement of the respective metal oxides by the nitrides takes place. Formation of the C-N bonds was observed for both ultrathin a-C:H and ultrathin a-CN x :H layers deposited onto the nitrided steel. Some Fe and/or Cr nitrides still were presented at the interface after the film deposition, too. Increased adhesion between the steel substrate and hydrogenated amorphous carbon layer after the ion beam nitridation was explained by three main factors. The first two is steel surface deoxidisation/passivation by nitrogen as a result of the ion beam treatment. The third one is carbon nitride formation at the nitrided steel-hydrogenated amorphous carbon (or a-CN x :H) film interface

Pulsed ion-beam assisted deposition of Ge nanocrystals on SiO2 for non-volatile memory device

International Nuclear Information System (INIS)

Stepina, N.P.; Dvurechenskii, A.V.; Armbrister, V.A.; Kirienko, V.V.; Novikov, P.L.; Kesler, V.G.; Gutakovskii, A.K.; Smagina, Z.V.; Spesivtzev, E.V.

2008-01-01

A floating gate memory structure, utilizing Ge nanocrystals (NCs) deposited on tunnel SiO 2 , have been fabricated using pulsed low energy ion-beam induced molecular-beam deposition (MBD) in ultra-high vacuum. The ion-beam action is shown to stimulate the nucleation of Ge NCs when being applied after thin Ge layer deposition. Growth conditions for independent change of NCs size and array density were established allowing to optimize the structure parameters required for memory device. Activation energy E = 0.25 eV was determined from the temperature dependence of NCs array density. Monte Carlo simulation has shown that the process, determining NCs array density, is the surface diffusion. Embedding of the crystalline Ge dots into silicon oxide was carried out by selective oxidation of Si(100)/SiO 2 /Ge(NCs)/poly-Si structure. MOS-capacitor obtained after oxidation showed a hysteresis in its C-V curves attributed to charge retention in the Ge dots

Characterization and in situ fluorescence diagnostic of the deposition of YBa2Cu3O7-x thin films by pseudo-spark electron beam ablation

International Nuclear Information System (INIS)

Jiang, Q.D.; Matacotta, F.C.; Masciarelli, G.; Fuso, F.; Arimondo, E.; Sandrin, G.

1992-12-01

The pseudo-spark electron beam ablation (PSA) technique is a comparatively simple and inexpensive method to deposit thin films of oxide materials. The effect of the electron beam power density on the efficiency of the PSA is studied. Results concerning the optimization of the deposition process of high quality superconducting YBa 2 Cu 3 O 7-x thin films on single crystal SrTiO 3 substrates are reported. Correlation between processing parameters and superconducting properties of the thin films are presented: in particular, the effects of the break-down voltage of the pseudo-spark and geometrical arrangement of the target-substrate-beam system on the T c of the resulting films. In situ spectral analysis of the radiative emission from the plasma plume has been performed at different distances from the surface of the target and at different break-down voltages of the pseudo-spark. The role of the oxygen pressure in the PSA process, which could be one order of magnitude less than that for a typical laser ablation system, is discussed. (author). 17 refs, 7 figs, 1 tab

Oxidation of nanostructured Ti films produced by low energy cluster beam deposition: An X-ray Photoelectron Spectroscopy characterization

International Nuclear Information System (INIS)

Simone, Monica de; Snidero, Elena; Coreno, Marcello; Bongiorno, Gero; Giorgetti, Luca; Amati, Matteo; Cepek, Cinzia

2012-01-01

We used in-situ X-ray Photoelectron Spectroscopy (XPS) to study the oxidation process of a cluster-assembled metallic titanium film exposed to molecular oxygen at room temperature. The nanostructured film has been grown on a Si(111) substrate, in ultra high vacuum conditions, by coupling a supersonic cluster beam deposition system with an XPS experimental chamber. Our results show that upon in-situ oxygen exposure Ti 3+ is the first oxidation state observed, followed by Ti 4+ , whereas Ti 2+ is practically absent during the whole process. Our results compare well with the existing literature on Ti films produced using other techniques.

Transport Properties of LCMO Granular Films Deposited by the Pulsed Electron Deposition Technique

Institute of Scientific and Technical Information of China (English)

CHEN Leiming; XU Bin; ZHANG Yan; CHEN Zhenping

2011-01-01

By finely controlling the deposition parameters in the pulsed electron deposition process,granular La2/3Ca1/3MnO3 (LCMO) film was grown on silicon substrates.The substrate temperature,ambient pressure in the deposition chamber and acceleration potential for the electron beam were all found to affect the grain size of the film,resulting in different morphologies of the samples.Transport properties of the obtained granular films,especially the magnetoresistance (MR),were studied.Prominent low-field MR was observed in all samples,indicating the forming of grain boundaries in the sample.The low-field MR show great sensitive to the morphology evolution,which reaches the highest value of about 40％ for the sample with the grain size of about 250 nm.More interestingly,positive-MR (p-MR) was also detected above 300 K when low magnetic field applying,whereas it disappeared with higher magnetic field applied up to 1.5 and 2 Tesla.Instead of the spinpolarized tunneling process being commonly regarded as a responsible reason,lattice mismatch between LCMO film and silicon substrate appears to be the origin of the p-MR

Radial electron beam laser excitation: the REBLE report

International Nuclear Information System (INIS)

Ramirez, J.J.; Prestwich, K.R.

1978-10-01

The results of an investigation of techniques to generate high-power radially converging electron beams and the application of these beams to gas lasers is discussed. The design and performance of the REBLE accelerator that was developed for this program is presented. Reliable operation of the radial diode has been obtained at levels up to 1 MV, 200 kA, and 20 ns. It has been demonstrated that the anode current density can be made uniform to better than 15% over 1000 cm 2 areas with 100 to 250 A/cm 2 intensities. The measured total and spatially resolved energy deposition of this radial electron beam in various gases is compared with Monte Carlo calculations. In most cases, these codes give an accurate description of the beam transport and energy deposition. With the electron beam pumping xenon gas, the amplitude of xenon excimer radiation (1720 A 0 ) was radially uniform to within the experimental uncertainty. The efficiency of converting deposited electron beam energy to xenon excimer radiation was 20%

Thermal barrier coatings of rare earth materials deposited by electron beam-physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Xu Zhenhua [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); He Limin, E-mail: he_limin@yahoo.co [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Chen Xiaolong; Zhao Yu [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Cao Xueqiang, E-mail: xcao@ciac.jl.c [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2010-10-15

Thermal barrier coatings (TBCs) have very important applications in gas turbines for higher thermal efficiency and protection of components at high temperature. TBCs of rare earth materials such as lanthanum zirconate (La{sub 2}Zr{sub 2}O{sub 7}, LZ), lanthanum cerate (La{sub 2}Ce{sub 2}O{sub 7}, LC), lanthanum cerium zirconate (La{sub 2}(Zr{sub 0.7}Ce{sub 0.3}){sub 2}O{sub 7}, LZ7C3) were prepared by electron beam-physical vapor deposition (EB-PVD). The composition, crystal structure, cross-sectional morphology and cyclic oxidation behavior of these coatings were studied. These coatings have partially deviated from their original compositions due to the different evaporation rates of oxides, and the deviation could be reduced by properly controlling the deposition condition. A double ceramic layer-thermal barrier coatings (DCL-TBCs) of LZ7C3 and LC could also be deposited with a single LZ7C3 ingot by properly controlling the deposition energy. LaAlO{sub 3} is formed due to the chemical reaction between LC and Al{sub 2}O{sub 3} in the thermally grown oxide (TGO) layer. The failure of DCL-TBCs is a result of the sintering-induced of LZ7C3 coating and the chemical incompatibility of LC and TGO. Since no single material that has been studied so far satisfies all the requirements for high temperature applications, DCL-TBCs are an important development direction of TBCs.

Electropolymerization of pyrrole on oxidizable metal under high frequency ultrasound irradiation. Application of focused beam to a selective masking technique

Energy Technology Data Exchange (ETDEWEB)

Et Taouil, A. [Institut UTINAM, UMR 6213 CNRS, Universite de Franche-Comte, 30 Avenue de l' observatoire, 25009 Besancon Cedex (France); Lallemand, F., E-mail: fabrice.lallemand@univ-fcomte.f [Institut UTINAM, UMR 6213 CNRS, Universite de Franche-Comte, 30 Avenue de l' observatoire, 25009 Besancon Cedex (France); Hallez, L.; Hihn, J-Y. [Institut UTINAM, UMR 6213 CNRS, Universite de Franche-Comte, 30 Avenue de l' observatoire, 25009 Besancon Cedex (France)

2010-12-01

A novel masking technique against polymer deposition based on High Intensity Focused Ultrasound (HIFU) irradiation was developed for the first time. With this in mind, a variety of background salts were tested. Sodium salicylate was found to be the most effective electrolytic medium for pyrrole sonoelectropolymerization on copper as it leads to a very efficient passivating oxide layer preventing copper dissolution while enabling polymer formation independently from sonication. In such a medium, high frequency ultrasound greatly refines surface structure, and a slight increase in doping level is observed. Finally, it was proved that focused ultrasound increases copper dissolution in sodium oxalate electrolyte while preventing polypyrrole deposition. A selected zone on the copper substrate was thus irradiated by the focused ultrasound beam to protect it from polymerization. In a second stage, a self-assembled monolayer was deposited on this polymer-free area to create a surface biphased substrate. This type of masking technique can be proposed as an interesting alternative to lithography as it is easier to carry out and allows chemical waste reduction.

Dose calculation methods in photon beam therapy using energy deposition kernels

International Nuclear Information System (INIS)

Ahnesjoe, A.

1991-01-01

The problem of calculating accurate dose distributions in treatment planning of megavoltage photon radiation therapy has been studied. New dose calculation algorithms using energy deposition kernels have been developed. The kernels describe the transfer of energy by secondary particles from a primary photon interaction site to its surroundings. Monte Carlo simulations of particle transport have been used for derivation of kernels for primary photon energies form 0.1 MeV to 50 MeV. The trade off between accuracy and calculational speed has been addressed by the development of two algorithms; one point oriented with low computional overhead for interactive use and one for fast and accurate calculation of dose distributions in a 3-dimensional lattice. The latter algorithm models secondary particle transport in heterogeneous tissue by scaling energy deposition kernels with the electron density of the tissue. The accuracy of the methods has been tested using full Monte Carlo simulations for different geometries, and found to be superior to conventional algorithms based on scaling of broad beam dose distributions. Methods have also been developed for characterization of clinical photon beams in entities appropriate for kernel based calculation models. By approximating the spectrum as laterally invariant, an effective spectrum and dose distribution for contaminating charge particles are derived form depth dose distributions measured in water, using analytical constraints. The spectrum is used to calculate kernels by superposition of monoenergetic kernels. The lateral energy fluence distribution is determined by deconvolving measured lateral dose distributions by a corresponding pencil beam kernel. Dose distributions for contaminating photons are described using two different methods, one for estimation of the dose outside of the collimated beam, and the other for calibration of output factors derived from kernel based dose calculations. (au)

Growth of group III nitride films by pulsed electron beam deposition

International Nuclear Information System (INIS)

Ohta, J.; Sakurada, K.; Shih, F.-Y.; Kobayashi, A.; Fujioka, H.

2009-01-01

We have grown group III nitride films on Al 2 O 3 (0 0 0 1), 6H-SiC (0 0 0 1), and ZnO (0001-bar) substrates by pulsed electron beam deposition (PED) for the first time and investigated their characteristics. We found that c-plane AlN and GaN grow epitaxially on these substrates. It has been revealed that the growth of GaN on atomically flat 6H-SiC substrates starts with the three-dimensional mode and eventually changes into the two-dimensional mode. The GaN films exhibited strong near-band-edge emission in their room temperature photoluminescence spectra. We also found that the use of PED allows us to reduce the epitaxial growth temperature for GaN down to 200 deg. C. - Graphical abstract: We have grown group III nitride films by pulsed electron beam deposition (PED) and found that the films of group III nitrides grow epitaxially on 6H-SiC and Al 2 O 3 substrates. We also found that the use of PED allows us to reduce the epitaxial growth temperature for GaN down to 200 deg. C.

Electrical performance of phase change memory cells with Ge{sub 3}Sb{sub 2}Te{sub 6} deposited by molecular beam epitaxy

Energy Technology Data Exchange (ETDEWEB)

Boschker, Jos E.; Riechert, Henning; Calarco, Raffaella [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany); Boniardi, Mattia; Redaelli, Andrea [Micron Semiconductor Italia S.r.l., Via C. Olivetti, 2, 20864, Agrate Brianza, MB (Italy)

2015-01-12

Here, we report on the electrical characterization of phase change memory cells containing a Ge{sub 3}Sb{sub 2}Te{sub 6} (GST) alloy grown in its crystalline form by Molecular Beam Epitaxy (MBE). It is found that the high temperature growth on the amorphous substrate results in a polycrystalline film exhibiting a rough surface with a grain size of approximately 80–150 nm. A detailed electrical characterization has been performed, including I-V characteristic curves, programming curves, set operation performance, crystallization activation at low temperature, and resistance drift, in order to determine the material related parameters. The results indicate very good alignment of the electrical parameters with the current state-of-the-art GST, deposited by physical vapor deposition. Such alignment enables a possible employment of the MBE deposition technique for chalcogenide materials in the phase change memory technology, thus leading to future studies of as-deposited crystalline chalcogenides as integrated in electrical vehicles.

Biased Target Ion Beam Deposition and Nanoskiving for Fabricating NiTi Alloy Nanowires

Science.gov (United States)

Hou, Huilong; Horn, Mark W.; Hamilton, Reginald F.

2016-12-01

Nanoskiving is a novel nanofabrication technique to produce shape memory alloy nanowires. Our previous work was the first to successfully fabricate NiTi alloy nanowires using the top-down approach, which leverages thin film technology and ultramicrotomy for ultra-thin sectioning. For this work, we utilized biased target ion beam deposition technology to fabricate nanoscale (i.e., sub-micrometer) NiTi alloy thin films. In contrast to our previous work, rapid thermal annealing was employed for heat treatment, and the B2 austenite to R-phase martensitic transformation was confirmed using stress-temperature and diffraction measurements. The ultramicrotome was programmable and facilitated sectioning the films to produce nanowires with thickness-to-width ratios ranging from 4:1 to 16:1. Energy dispersive X-ray spectroscopy analysis confirmed the elemental Ni and Ti make-up of the wires. The findings exposed the nanowires exhibited a natural ribbon-like curvature, which depended on the thickness-to-width ratio. The results demonstrate nanoskiving is a potential nanofabrication technique for producing NiTi alloy nanowires that are continuous with an unprecedented length on the order of hundreds of micrometers.

The status and new trends of ion beam induced charge technique

International Nuclear Information System (INIS)

Lu Rongrong; Qiu Huiyuan; Zhu Dezhang

2002-01-01

Ion beam induced charge technique (IBIC) with low beam current (fA level) and high efficiency is a new development of nuclear microscopy. It has been widely applied to the fields of semiconductor and microelectronic materials. The principle and the experimental method of the IBIC technique were described and reviewed its status and new trends were reviewed

Development of a computerized tomographic system based on the FAN-BEAM technique

International Nuclear Information System (INIS)

Junqueira, M.M.; Santos, C.A.C.; Borges, J.C.

1986-01-01

The Nuclear Instrumentation Laboratory, at COPPE/UFRJ, concentrates its researches in the development of computerized tomographic systems, looking for applications in industrial and medical non destructive analysing techniques. In this work we have projected and constructed a tomographic prototype, based on the FAN-BEAM technique for irradiating the object under analysis. An algorithm previously developed to analyse parallel beams, was modified and adapted to the FAN-BEAM geometry. (Author) [pt

Introduction to analytical techniques of beam-target interactions and resolutions

International Nuclear Information System (INIS)

Ruste, J.

1995-08-01

For several years, new analysis and observation techniques have been developed, which have considerably improved material research. Almost all these techniques are based on the interaction of a beam of 'primary particles' (electrons, photons, ions, particles, etc) with target. Correct and appropriate use of these techniques requires a good knowledge of these interactions and their consequences (emissions of 'secondary particles', modifications of the primary beam and target, etc). The first part of this report deals with the radiation/material interactions according to the nature of the radiation and its energy. The nature and consequences of the interaction of an electromagnetic wave, a beam of electrons, ions and neutrons are examined over an extended range of energy from MeV to MeV. Certain notions such as the analysis area, spatial resolutions or limits of detection can also be defined. In the second part, some of the most important and widespread techniques of analysis and observation are compared in terms of properties and performance. In particular, there is a brief principle of the technique, nature of the data obtained, spatial resolution, and the limits of detection with today's methods permit. (author). 5 refs., 23 figs., 9 tabs

Application of a transverse phase-space measurement technique for high-brightness, H- beams to the GTA H- beam

International Nuclear Information System (INIS)

Johnson, K.F.; Garcia, R.C.; Rusthoi, D.P.; Sander, O.R.; Sandoval, D.P.; Shinas, M.A.; Smith, M.; Yuan, V.W.; Connolly, R.C.

1995-01-01

The Ground Test Accelerator (GTA) had the objective Of Producing a high-brightness, high-current H-beam. The major components were a 35 keV injector, a Radio Frequency Quadrupole (RFQ), an intertank matching section (IMS), and a drift tube linac (DTL), consisting of 10 modules. A technique for measuring the transverse phase-space of high-power density beams has been developed and tested. This diagnostic has been applied to the GTA H-beam. Experimental results are compared to the slit and collector technique for transverse phase-space measurements and to simulations

Annealing of TiO2 Films Deposited on Si by Irradiating Nitrogen Ion Beams

International Nuclear Information System (INIS)

Yokota, Katsuhiro; Yano, Yoshinori; Miyashita, Fumiyoshi

2006-01-01

Thin TiO2 films were deposited on Si at a temperature of 600 deg. C by an ion beam assisted deposition (IBAD) method. The TiO2 films were annealed for 30 min in Ar at temperatures below 700 deg. C. The as-deposited TiO2 films had high permittivities such 200 εo and consisted of crystallites that were not preferentially oriented to the c-axis but had an expanded c-axis. On the annealed TiO2 films, permittivities became lower with increasing annealing temperature, and crystallites were oriented preferentially to the (110) plane

Pulsed ion-beam assisted deposition of Ge nanocrystals on SiO{sub 2} for non-volatile memory device

Energy Technology Data Exchange (ETDEWEB)

Stepina, N.P. [Institute of Semiconductor Physics, Lavrenteva 13, 630090 Novosibirsk (Russian Federation)], E-mail: nstepina@mail.ru; Dvurechenskii, A.V.; Armbrister, V.A.; Kirienko, V.V.; Novikov, P.L.; Kesler, V.G.; Gutakovskii, A.K.; Smagina, Z.V.; Spesivtzev, E.V. [Institute of Semiconductor Physics, Lavrenteva 13, 630090 Novosibirsk (Russian Federation)

2008-11-03

A floating gate memory structure, utilizing Ge nanocrystals (NCs) deposited on tunnel SiO{sub 2}, have been fabricated using pulsed low energy ion-beam induced molecular-beam deposition (MBD) in ultra-high vacuum. The ion-beam action is shown to stimulate the nucleation of Ge NCs when being applied after thin Ge layer deposition. Growth conditions for independent change of NCs size and array density were established allowing to optimize the structure parameters required for memory device. Activation energy E = 0.25 eV was determined from the temperature dependence of NCs array density. Monte Carlo simulation has shown that the process, determining NCs array density, is the surface diffusion. Embedding of the crystalline Ge dots into silicon oxide was carried out by selective oxidation of Si(100)/SiO{sub 2} /Ge(NCs)/poly-Si structure. MOS-capacitor obtained after oxidation showed a hysteresis in its C-V curves attributed to charge retention in the Ge dots.

A feasibility study of H{sup -} beam extraction technique using YAG laser

Energy Technology Data Exchange (ETDEWEB)

Meigo, Shin-ichiro; Hasegawa, Kazuo; Ikeda, Yujiro; Oigawa, Hiroyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Aoki, Nobutada [Toshiba Power System Co., Ltd. (Japan); Nakagawa, Satoshi [Toshiba Co., Tokyo (Japan)

2002-12-01

Under a framework of JAERI-KEK joint project of high intensity proton accelerator, as for research and develop of the accelerator driven nuclear transmutation of the long lived radioactive nuclide, it is planed to built the Transmutation Physics Experiment Facility (TEF-P) and the Transmutation Engineering Experiment Facility (TEF-E). The TEF-P is used for the experiments for subcritical system coupled with a spallation neutron target bombarded with 600-MeV proton beam accelerated by the LINAC. To limit the maximum thermal power less than 500 W at the TEF-P, an incident beam power should be less than 10 W. On the contrary, at the TEF-E, high power beam of 200 kW is requested. Both high and low power beams are demanded for the transmutation facilities. It is difficult to deliver a low power beam to the TEF-P. Conventional beam extraction technique with a thin foil, is not desirable because the scattering of the beam at the foil requires the massive shield. Therefore, we study a new technique to extract a small portion of the beam precisely from the high intensity beam by using a laser beam. By a laser beam, H{sup -} in the beam from LINAC is partially changed to H{sup 0} beam so that a low current H{sup 0} beam can be obtained. As the cross section of the charge exchange reaction for H{sup -} ions has a peak around at a wave length of 1 {mu}m for photons, YAG laser is suitable for this charge exchange because of its 1.06 {mu}m wave length. It is derived that 10 W beam for 600-MeV proton can be extracted by the YAG laser with power of 2 J for each pulse of 25 Hz. By this technique, the pulse width for the extracted beam can be controlled by changing the time width of laser irradiation. When a charge exchanger having the beam collide point existing in straight section, a background beam current of projectile, however, will be increased due to the interaction with the residual gas in the beam duct. Thus, a charge exchanger is devised having the beam collide point in a

Analysis of sub-bandgap losses in TiO2 coating deposited via single and dual ion beam deposition

Czech Academy of Sciences Publication Activity Database

Žídek, Karel; Hlubuček, Jiří; Horodyská, Petra; Budasz, Jiří; Václavík, Jan

2017-01-01

Roč. 626, March (2017), s. 60-65 ISSN 0040-6090 R&D Projects: GA MŠk(CZ) LO1206 Institutional support: RVO:61389021 Keywords : Ion beam deposition * Titanium dioxide * Optical coating * Sub-bandgap losses * Urbach tail Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 1.879, year: 2016 http://www.sciencedirect.com/science/article/pii/S0040609017301256

Techniques for beam impedance measurements above cutoff

International Nuclear Information System (INIS)

Lambertson, G.R.; Jacob, A.F.; Rimmer, R.A.; Voelker, F.

1990-08-01

Methods for measuring beam impedance above cutoff have been very limited. For design work on the ALS we have developed two techniques that yield data in the frequency domain with high sensitivity. The first is an extension of the wire method; the second utilizes traveling TM waves to simulate the beam's fields at the wall, and thus avoids the mechanical difficulties of mounting the wire. It is also more sensitive than the other method but the interpretation is complicated by the presence of higher order modes. With either method we were able to detect resonant peaks smaller than 1 Ohm at 10 GHz

Atomic layer deposition of HfO2 on graphene through controlled ion beam treatment

International Nuclear Information System (INIS)

Kim, Ki Seok; Oh, Il-Kwon; Jung, Hanearl; Kim, Hyungjun; Yeom, Geun Young; Kim, Kyong Nam

2016-01-01

The polymer residue generated during the graphene transfer process to the substrate tends to cause problems (e.g., a decrease in electron mobility, unwanted doping, and non-uniform deposition of the dielectric material). In this study, by using a controllable low-energy Ar + ion beam, we cleaned the polymer residue without damaging the graphene network. HfO 2 grown by atomic layer deposition on graphene cleaned using an Ar + ion beam showed a dense uniform structure, whereas that grown on the transferred graphene (before Ar + ion cleaning) showed a non-uniform structure. A graphene–HfO 2 –metal capacitor fabricated by growing 20-nm thick HfO 2 on graphene exhibited a very low leakage current (<10 −11 A/cm 2 ) for Ar + ion-cleaned graphene, whereas a similar capacitor grown using the transferred graphene showed high leakage current.

The charge deposition in the numerical simulation of high-current beam

International Nuclear Information System (INIS)

Wang Shijun

1987-01-01

A new method of charge deposition of high-current beam, conservation-map method, is given. THe advantages of Neil's and other various methods are adopted. The mistake of Neil's method and the limitation of other various methods is discarded. So the method is accurate without additional assumption. The method not only applies to the case of steady laminar flow but also applies to the case of steady non-laminar flow

Five second helium neutral beam injection using argon-frost cryopumping techniques

International Nuclear Information System (INIS)

Phillips, J.C.; Kellman, D.H.; Hong, R.; Kim, J.; Laughon, G.M.

1995-01-01

High power helium neutral beams for the heating of tokamak discharges can now be provided for 5 s by using argon cryopumping (of the helium gas) in the beamlines. The DIII-D neutral beam system has routinely provided up to 20 MW of deuterium neutral beam heating in support of experiments on the DIII-D tokamak. Operation of neutral beams with helium has historically presented a problem in that pulse lengths have been limited to 500 ms due to reliance solely on volume pumping of the helium gas. Helium is not condensed on the cryopanels. A system has now been installed to deposit a layer of argon frost on the DIII-D neutral beam cryopanels, between tokamak injection pulses. The layer serves to trap helium on the cryopanels providing sufficient pumping speed for 5 s helium beam extraction. The argon frosting hardware is now present on two of four DIII-D neutral beamlines, allowing injection of up to 6 MW of helium neutral beams per discharge, with pulse lengths of up to 5 s. The argon frosting system is described, along with experimental results demonstrating its effectiveness as a method of economically extending the capabilities of cryogenic pumping panels to allow multi-second helium neutral beam injection

Compensation techniques in NIRS proton beam radiotherapy

International Nuclear Information System (INIS)

Akanuma, A.; Majima, H.; Furukawa, S.

1982-01-01

Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods

Compensation techniques in NIRS proton beam radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Akanuma, A. (Univ. of Tokyo, Japan); Majima, H.; Furukawa, S.

1982-09-01

Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods.

Ion Beam Assisted Deposition of Thin Epitaxial GaN Films.

Science.gov (United States)

Rauschenbach, Bernd; Lotnyk, Andriy; Neumann, Lena; Poppitz, David; Gerlach, Jürgen W

2017-06-23

The assistance of thin film deposition with low-energy ion bombardment influences their final properties significantly. Especially, the application of so-called hyperthermal ions (energy GaN thin films on (0001)-oriented 6H-SiC substrates at 700 °C. The films are studied in situ by reflection high energy electron diffraction, ex situ by X-ray diffraction, scanning tunnelling microscopy, and high-resolution transmission electron microscopy. It is demonstrated that the film growth mode can be controlled by varying the ion to atom ratio, where 2D films are characterized by a smooth topography, a high crystalline quality, low biaxial stress, and low defect density. Typical structural defects in the GaN thin films were identified as basal plane stacking faults, low-angle grain boundaries forming between w-GaN and z-GaN and twin boundaries. The misfit strain between the GaN thin films and substrates is relieved by the generation of edge dislocations in the first and second monolayers of GaN thin films and of misfit interfacial dislocations. It can be demonstrated that the low-energy nitrogen ion assisted molecular beam epitaxy is a technique to produce thin GaN films of high crystalline quality.

Magnetically scanned proton therapy beams: rationales and techniques

International Nuclear Information System (INIS)

Jones, D.T.L.; Schreuder, A.N.

2000-01-01

Perhaps the most important advantages of beam scanning systems for proton therapy in comparison with conventional passive beam spreading systems are: (1) Intensity modulation and inverse planning are possible. (2) There is negligible reduction in the range of the beam. (3) Integral dose is reduced as dose conformation to the proximal edge of the lesion is possible. (4) In principle no field-specific modifying devices are required. (5) There is less activation of the surroundings. (6) Scanning systems axe almost infinitely flexible. The main disadvantages include: (1) Scanning systems are more complicated and therefore potentially less reliable and more dangerous. (2) The development of such systems is more demanding in terms of cost, time and manpower. (3) More stable beams are required. (4) Dose and beam position monitoring are more difficult. (5) The problems associated with patient and organ movement axe more severe. There are several techniques which can be used for scanning. For lateral beam spreading, circular scanning (wobbling) or linear scanning can be done. In the latter case the beam can be scanned continuously or in a discrete fashion (spot scanning). Another possibility is to undertake the fastest scan in one dimension (strip scanning) and translate the patient or the scanning magnet in the other dimension. Depth variation is achieved by interposing degraders in the beam (cyclotrons) or by changing the beam energy (synchrotrons). The aim of beam scanning is to deliver a predetermined dose at any point in the body. Special safety precautions must be taken because of the high instantaneous dose rates. The beam position and the dose delivered at each point must be accurately and redundantly determined. (author)

Fabrication of 100 A class, 1 m long coated conductor tapes by metal organic chemical vapor deposition and pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Selvamanickam, V.; Lee, H.G.; Li, Y.; Xiong, X.; Qiao, Y.; Reeves, J.; Xie, Y.; Knoll, A.; Lenseth, K

2003-10-15

SuperPower has been scaling up YBa{sub 2}Cu{sub 3}O{sub x}-based second-generation superconducting tapes by techniques such as pulsed laser deposition (PLD) using industrial laser and metal organic chemical vapor deposition (MOCVD). Both techniques offer advantage of high deposition rates, which is important for high throughput. Using highly-polished substrates produced in a reel-to-reel polishing facility and buffer layers deposited in a pilot ion beam assisted deposition facility, meter-long second-generation high temperature superconductor tapes have been produced. 100 A class, meter-long coated conductor tapes have been reproducibly demonstrated in this work by both MOCVD and PLD. The best results to date are 148 A over 1.06 m by MOCVD and 135 A over 1.1 m by PLD using industrial laser.

Modification of thin film properties by ion bombardment during deposition

International Nuclear Information System (INIS)

Harper, J.M.E.; Cuomo, J.J.; Gambino, R.J.; Kaufman, H.R.

1984-01-01

Many thin film deposition techniques involve some form of energetic particle bombardment of the growing film. The degree of bombardment greatly influences the film composition, structure and other properties. While in some techniques the degree of bombardment is secondary to the original process design, in recent years more deposition systems are being designed with the capability for controlled ion bombardment of thin films during deposition. The highest degree of control is obtained with ion beam sources which operate independently of the vapor source providing the thin film material. Other plasma techniques offer varying degrees of control of energetic particle bombardment. Deposition methods involving ion bombardment are described, and the basic processes with which film properties are modified by ion bombardment are summarized. (Auth.)

Diamond like carbon coatings deposited by microwave plasma CVD ...

Indian Academy of Sciences (India)

WINTEC

photoelectron spectroscopy (XPS) and spectroscopic ellipsometry techniques for estimating sp. 3. /sp. 2 ratio. ... ion beam deposition (Savvidas 1986), pulsed laser deposi- ... carrier gas (10 sccm) by passing 150 watts of microwave power.

Flexible, ionic liquid-based micro-supercapacitor produced by supersonic cluster beam deposition

International Nuclear Information System (INIS)

Bettini, L.G.; Piseri, P.; De Giorgio, F.; Arbizzani, C.; Milani, P.; Soavi, F.

2015-01-01

Highlights: • We exploited Supersonic Cluster Beam Deposition for the fabrication of a flexible, planar micro-supercapacitor featuring nanostructured carbon electrodes deposited on a plastic Mylar substrate and N-trimethyl-N-propyl-ammonium bis(trifluoromethanesulfonyl) imide (N 1113 TFSI) ionic liquid electrolyte. • The micro-supercapacitor operates at 3 V above RT up to 80 °C with a capacitance density approaching 10 F cm −3 and delivering maximum specific energy and power densities of 10 mWh cm −3 and 8-10 W cm −3 . • The micro-supercapacitor features long cycling stability over 2x10 4 cycle on flat and bent configuration. -- Graphical abstract: Display Omitted -- Abstract: Power generation and storage in electronics require flexible, thin micro-electrochemical energy storage/conversion systems. Micro-supercapacitors (μSCs) with double-layer capacitance carbon electrodes are attracting much attention for their capability of delivering short power pulses with high stability over repeated charge/discharge cycling. Supersonic Cluster Beam Deposition (SCBD) is an effective strategy for the development of nanostructured, binder-free porous carbon electrodes on temperature sensitive substrates including polymers. We exploited SCBD for the development of a flexible, planar μSC featuring nanostructured carbon (ns-C) electrodes deposited on a plastic Mylar substrate and N-trimethyl-N-propyl-ammonium bis(trifluoromethanesulfonyl) imide (N 1113 TFSI) ionic liquid electrolyte. The electrochemical performance at different temperatures of the μSC which operates at 3 V above RT up to 80 °C with a capacitance density approaching 10 F cm −3 and delivering maximum specific energy and power densities of 10 mWh cm −3 and 8-10 W cm −3 with long cycling stability over 2 × 10 4 cycles is here reported and discussed

Cumulative percent energy deposition of photon beam incident on different targets, simulated by Monte Carlo

International Nuclear Information System (INIS)

Kandic, A.; Jevremovic, T.; Boreli, F.

1989-01-01

Monte Carlo simulation (without secondary radiation) of the standard photon interactions (Compton scattering, photoelectric absorption and pair protection) for the complex slab's geometry is used in numerical code ACCA. A typical ACCA run will yield: (a) transmission of primary photon radiation differential in energy, (b) the spectrum of energy deposited in the target as a function of position and (c) the cumulative percent energy deposition as a function of position. A cumulative percent energy deposition of photon monoenergetic beam incident on simplest and complexity tissue slab and Fe slab are presented in this paper. (author). 5 refs.; 2 figs

New diagnostic technique for Zeeman-compensated atomic beam slowing: technique and results

NARCIS (Netherlands)

Molenaar, P.A.; Straten, P. van der; Heideman, H.G.M.; Metcalf, H.

1997-01-01

We have developed a new diagnostic tool for the study of Zeeman-compensated slowing of an alkali atomic beam. Our time-of-flight technique measures the longitudinal veloc- ity distribution of the slowed atoms with a resolution below the Doppler limit of 30 cm/s. Furthermore, it can map

New diagnostic technique for Zeeman-compensated atomic beam slowing: technique and results

OpenAIRE

Molenaar, P.A.; Straten, P. van der; Heideman, H.G.M.; Metcalf, H.

1997-01-01

We have developed a new diagnostic tool for the study of Zeeman-compensated slowing of an alkali atomic beam. Our time-of-flight technique measures the longitudinal veloc- ity distribution of the slowed atoms with a resolution below the Doppler limit of 30 cm/s. Furthermore, it can map the position and velocity distribution of atoms in either ground hyperfine level inside the solenoid without any devices inside the solenoid. The technique reveals the optical pumping ef- fects, and shows in de...

Mechanical characteristics of a tool steel layer deposited by using direct energy deposition

Science.gov (United States)

Baek, Gyeong Yun; Shin, Gwang Yong; Lee, Eun Mi; Shim, Do Sik; Lee, Ki Yong; Yoon, Hi-Seak; Kim, Myoung Ho

2017-07-01

This study focuses on the mechanical characteristics of layered tool steel deposited using direct energy deposition (DED) technology. In the DED technique, a laser beam bonds injected metal powder and a thin layer of substrate via melting. In this study, AISI D2 substrate was hardfaced with AISI H13 and M2 metal powders for mechanical testing. The mechanical and metallurgical characteristics of each specimen were investigated via microstructure observation and hardness, wear, and impact tests. The obtained characteristics were compared with those of heat-treated tool steel. The microstructures of the H13- and M2-deposited specimens show fine cellular-dendrite solidification structures due to melting and subsequent rapid cooling. Moreover, the cellular grains of the deposited M2 layer were smaller than those of the H13 structure. The hardness and wear resistance were most improved in the M2-deposited specimen, yet the H13-deposited specimen had higher fracture toughness than the M2-deposited specimen and heat-treated D2.

The beam based alignment technique for the measurements of beam position monitors offsets and beam offsets from quadrupoles in the Pohang Light Source

International Nuclear Information System (INIS)

Kim, K.H.; Huang, J.Y.; Ko, I.S.

1999-01-01

The beam based alignment (BBA) technique is applied to the 2-GeV storage ring of the Pohang Light Source to measure the offsets of beam position monitors. This measurement is particularly necessary for beam position monitors (BPMs) plugged into a long (∼10 m) aluminum chamber, since the mechanical deformation of the vacuum chamber is experienced after repeated heating for the outgassing process, and the BPM positions are changed accordingly. A part of the excitation current of each quadrupole magnet is shunted through an electronic shunt circuit. Then, the closed orbit receives a perturbation due to the current reduction. Using two quadrupole magnets, we can measure the offset of each BPM. Also, the BBA technique is applied to measure the beam offsets from the center of quadrupole magnets, and gives information to the survey team about which quadrupole magnets should be aligned mostly. In this process, we introduce the merit function to reduce various errors such as BPM characteristic changes and the lattice imperfection. By minimizing the merit function, we can get the beam offset as the maximized expectation value. This paper presents the BBA technique used and experimental results taken from the 2-GeV Pohang Light Source (PLS) storage ring. When the BPM offset is measured, it is observed that a 3% of the shunt current is suitable. (author)

Mechanical properties of micro-sized copper bending beams machined by the focused ion beam technique

International Nuclear Information System (INIS)

Motz, C.; Schoeberl, T.; Pippan, R.

2005-01-01

Micro-sized bending beams with thicknesses, t, from 7.5 down to 1.0 μm were fabricated with the focused ion beam technique from a copper single crystal with an {1 1 1} orientation. The beams were loaded with a nano-indenter and the force vs. displacement curves were recorded. A strong size effect was found where the flow stress reaches almost 1 GPa for the thinnest beams. A common strain gradient plasticity approach was used to explain the size effect. However, the strong t -1.14 dependence of the flow stress could not be explained by this model. Additionally, the combination of two other dislocation mechanisms is discussed: the limitation of available dislocation sources and a dislocation pile-up at the beam centre. The contribution of the pile-up stress to the flow stress gives a t -1 dependence, which is in good agreement with the experimental results

An analytical simulation technique for cone-beam CT and pinhole SPECT

International Nuclear Information System (INIS)

Zhang Xuezhu; Qi Yujin

2011-01-01

This study was aimed at developing an efficient simulation technique with an ordinary PC. The work involved derivation of mathematical operators, analytic phantom generations, and effective analytical projectors developing for cone-beam CT and pinhole SPECT imaging. The computer simulations based on the analytical projectors were developed by ray-tracing method for cone-beam CT and voxel-driven method for pinhole SPECT of degrading blurring. The 3D Shepp-Logan, Jaszczak and Defrise phantoms were used for simulation evaluations and image reconstructions. The reconstructed phantom images were of good accuracy with the phantoms. The results showed that the analytical simulation technique is an efficient tool for studying cone-beam CT and pinhole SPECT imaging. (authors)

Radiation therapy for retinoblastoma: comparison of results with lens-sparing versus lateral beam techniques

International Nuclear Information System (INIS)

McCormick, B.; Ellsworth, R.; Abramson, D.; Haik, B.; Tome, M.; Grabowski, E.; LoSasso, T.

1988-01-01

From 1979 through 1986, 170 children were seen at our institution diagnosed with retinoblastoma. Sixty-six of the children with involvement of 121 eyes, were referred for definitive external beam radiation to one or both eyes. During the study period, two distinct radiation techniques were used. From 1980 through mid-1984, a lens-sparing technique included an anterior electron beam with a contact lens mounted lead shield, combined with a lateral field, was used. Since mid-1984, a modified lateral beam technique has been used, mixing lateral electrons and superior and inferior lateral oblique split beam wedged photons. Doses prescribed were similar for both techniques, ranging from 3,850 to 5,000 cGy in 4 to 5 weeks. The lens-sparing and the modified lateral techniques are compared for local control. For eyes with Group I through III disease, the lens-sparing technique resulted in local control in 33% of the eyes treated, where the modified lateral technique controlled 83% of the eyes treated (p = .006). Mean time to relapse was identical in both groups, that is 24 and 26 months respectively. Most relapses were successfully treated with further local therapy, including laser or cryosurgery, or 60Co plaques. Five eyes required enucleation following initial treatment with the lens-sparing technique, but none thus far with the lateral beam technique. For eyes with Group IV and V disease, no significant differences were found between the two techniques in terms of local control or eventual need for enucleation. With a mean follow-up time of 33 months for the entire group, the 4-year survival is 93%. Two of the 4 deaths are due to second primary tumor, and all 4 have occurred in the lens-sparing group. Because follow-up time is more limited in the lateral beam group, this is not statistically significant and direct survival comparisons are premature

Improved beam-energy calibration technique for heavy ion accelerators

International Nuclear Information System (INIS)

Ferrero, A.M.J.; Garcia, A.; Gil, Salvador

1989-01-01

A simple technique for beam energy calibration of heavy-ion accelerators is presented. A thin hydrogenous target was bombarded with 12 C and 19 F, and the energies of the protons knocked out, elastically were measured at several angles using two detectors placed at equal angles on opposite sides of the beam. The use of these two detectors cancels the largest errors due to uncertainties in the angle and position at which the beam hits the target. An application of this energy calibration method to an electrostatic accelerator is described and the calibration constant of the analyzing magnet was obtained with an estimated error of 0.4 (Author) [es

New patterning paradigm? : selective deposition may be the way forward to the far reaches of device scaling after 7nm.

NARCIS (Netherlands)

Lapedus, M.; Kessels, W.M.M.

2015-01-01

The Eindhoven University of Technology, for one, is working on another approach—direct-write ALD. This is based on an area-selective ALD by an area-activation technique. This makes use of electron-beam induced deposition (EBID) or ion-beam induced deposition (IBID). "We combine the advantages of

Erosion behaviour of physically vapour-deposited and chemically vapour-deposited SiC films coated on molybdenum during oxygenated argon beam thinning

International Nuclear Information System (INIS)

Shikama, T.; Kitajima, M.; Fukutomi, M.; Okada, M.

1984-01-01

The erosion behaviour during bombardment with a 5 keV argon beam at room temperature was studied for silicon carbide (SiC) films of thickness of about 10 μm coated on molybdenum by physical vapour deposition (PVD) and chemical vapour deposition (CVD). The PVD SiC (plasma-assisted ion plating) exhibited a greater thinning rate than the CVD SiC film. Electron probe X-ray microanalysis revealed that the chemical composition of PVD SiC was changed to a composition enriched in silicon by the bombardment, and there was a notable change in its surface morphology. The CVD SiC retained its initial chemical composition with only a small change in its surface morphology. Auger electron spectroscopy indicated that silicon oxide was formed on the surface of PVD SiC by the bombardment. The greater thinning rate and easier change in chemical composition in PVD SiC could be attributed to its readier chemical reaction with oxygen due to its more non-uniform structure and weaker chemical bonding. Oxygen was present as one of the impurities in the argon beam. (Auth.)

Chemical vapor deposition: A technique for applying protective coatings

Energy Technology Data Exchange (ETDEWEB)

Wallace, T.C. Sr.; Bowman, M.G.

1979-01-01

Chemical vapor deposition is discussed as a technique for applying coatings for materials protection in energy systems. The fundamentals of the process are emphasized in order to establish a basis for understanding the relative advantages and limitations of the technique. Several examples of the successful application of CVD coating are described. 31 refs., and 18 figs.

An evaluation testing technique of single event effect using Beam Blanking SEM

Energy Technology Data Exchange (ETDEWEB)

Aoki, J; Hada, T; Pesce, A; Akutsu, T; Matsuda, S [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Igarashi, T; Baba, S

1997-03-01

Beam Blanking SEM (Scanning Electron Microscope) testing technique has been applied to CMOS SRAM devices to evaluate the occurence of soft errors on memory cells. Cross-section versus beam current and LET curves derived from BBSEM and heavy ion testing technique, respectively, have been compared. A linear relation between BBSEM current and heavy ion LET has been found. The purpose of this study was to demonstrate that the application of focused pulsed electron beam could be a reliable, convenient and inexpensive tool to investigate the effects of heavy ions and high energy particles on memory devices for space application. (author)

Positron deposition in plasmas by positronium beam ionization and transport of positrons in tokamak plasmas

International Nuclear Information System (INIS)

Murphy, T.J.

1986-11-01

In a recently proposed positron transport experiment, positrons would be deposited in a fusion plasma by forming a positronium (Ps) beam and passing it through the plasma. Positrons would be deposited as the beam is ionized by plasma ions and electrons. Radial transport of the positrons to the limiter could then be measured by detecting the gamma radiation produced by annihilation of positrons with electrons in the limiter. This would allow measurements of the transport of electron-mass particles and might shed some light on the mechanisms of electron transport in fusion plasmas. In this paper, the deposition and transport of positrons in a tokamak are simulated and the annihilation signal determined for several transport models. Calculations of the expected signals are necessary for the optimal design of a positron transport experiment. There are several mechanisms for the loss of positrons besides transport to the limiter. Annihilation with plasma electrons and reformation of positronium in positron-hydrogen collisions are two such processes. These processes can alter the signal and place restrictions ons on the plasma conditions in which positron transport experiments can be effectively performed

Electrochemical evaluation of under-deposit corrosion and its inhibition using the wire beam electrode method

Energy Technology Data Exchange (ETDEWEB)

Tan Yongjun, E-mail: yj.tan@curtin.edu.a [Western Australian Corrosion Research Group, Department of Chemistry, Curtin University, GPO Box U1987, Perth (Australia); Fwu, Young; Bhardwaj, Kriti [Western Australian Corrosion Research Group, Department of Chemistry, Curtin University, GPO Box U1987, Perth (Australia)

2011-04-15

Research highlights: A new experiment method for evaluating under-deposit corrosion and its inhibitors. Under-deposit corrosion did not occur in a CO{sub 2} saturated pure brine solution. Inhibitor imidazoline addition and O{sub 2} contamination initiated under-deposit corrosion. Inhibitor imidazoline reduced general corrosion but enhanced localised corrosion. - Abstract: A new experimental method has been applied to evaluate under-deposit corrosion and its inhibition by means of an electrochemically integrated multi-electrode array, namely the wire beam electrode (WBE). Maps showing galvanic current and corrosion potential distributions were measured from a WBE surface that was partially covered by sand. Under-deposit corrosion did not occur during the exposure of the WBE to carbon dioxide saturated brine under ambient temperature. The introduction of corrosion inhibitor imidazoline and oxygen into the brine was found to significantly affect the patterns and rates of corrosion, leading to the initiation of under-deposit corrosion over the WBE.

Modification of thin film properties by ion bombardment during deposition

International Nuclear Information System (INIS)

Harper, J.M.E.; Cuomo, J.J.; Gambino, R.J.; Kaufman, H.R.

1984-01-01

Deposition methods involving ion bombardment are described, and the basic processes with which film properties are modified by ion bombardment are summarized. Examples of thin film property modification by ion bombardment during deposition, including effects which are primarily compositional as well as those which are primarily structural are presented. The examples demonstrate the usefulness of ion beam techniques in identifying and controlling the fundamental deposition parameters. 68 refs.; 15 figs.; 1 table

Structural and magnetic properties of ion-beam bombarded Co/Pt multilayers

Energy Technology Data Exchange (ETDEWEB)

Lin, K.W.; Guo, J.Y.; Lin, S.R.; Ouyang, H. [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402 (China); Tsai, C.J. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300 (China); Van Lierop, J. [Department of Physics and Astronomy, University of Manitoba, Winnipeg (Canada); Phuoc, N.N.; Suzuki, T. [Information Storage Materials Laboratory, Toyota Technological Institute, Nagoya 468-8511 (Japan)

2007-12-15

A series of [Pt(2 nm)/Co(2 nm)]{sub 10}/Pt(30 nm) multilayers were deposited by using an ion-beam technique. X-ray diffraction and transmission electron microscopy results have shown that as-deposited samples consist of h.c.p. Co and f.c.c. Pt phases. Disordered CoPt{sub 3} phases were developed with increasing End-Hall voltage (V{sub EH}) that induces greater ion-beam bombardment energy during deposition. This indicates that intermixing of Co and Pt increases with ion-beam bombardment. The coercivities (ranging from 100 Oe to 300 Oe) of Co/Pt multilayers decreased with increasing V{sub EH}. After annealing, the formation of CoPt{sub 3} was observed in these ion-beam bombarded samples, resulting in lower coercivities (H{sub c}{proportional_to} 50 Oe). The depressed transition temperature of CoPt{sub 3} for films deposited with the largest V{sub EH} was attributed to distorted CoPt{sub 3} structures that appeared with annealing. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Minimal interference beam size/profile measurement techniques applicable to the Collider

International Nuclear Information System (INIS)

Nexsen, W.; Dutt, S.; Kauffmann, S.; Lebedev, V.; Maschke, A.; Mokhov, N.; Richardson, R.; Tsyganov, E.; Zinchenko, A.

1993-05-01

The imaging of synchrotron radiation (SR) has been suggested as a technique for providing a continuous, non-interfering monitor of the beam profile in the Collider rings at the Superconducting Super Collider. A closer examination has raised questions concerning the applicability of SR imaging in this case because of the diffraction broadening of the image, the requirements for axial space and location in the lattice, and the complexity of the system. We have surveyed the known, alternative, minimal interference techniques for measuring beam size and have evaluated them for possible Collider usage. We conclude that of the approaches that appear feasible, all require at least some development for our usage and that the development of an electron beam probe offers the best promise. We recommend that flying wires be used for cross-checking and calibrating the electron beam probe diagnostic and for luminosity measurements when the highest accuracy is required, but flying wires should not be used as the primary diagnostic because of their limited lifetime

A beam-based alignment technique for correction of accelerator structure misalignments

International Nuclear Information System (INIS)

Kubo, K.; Raubenheimer, T.O.

1994-08-01

This paper describes a method of reducing the transverse emittance dilution in linear colliders due to transverse wakefields arising-from misaligned accelerator structures. The technique is a generalization of the Wake-Free correction algorithm. The structure alignment errors are measured locally by varying the bunch charge and/or bunch length and measuring the change in the beam trajectory. The misalignments can then be corrected by varying the beam trajectory or moving structures. The results of simulations are presented demonstrating the viability of the technique

Beam-based alignment technique for the SLC [Stanford Linear Collider] linac

International Nuclear Information System (INIS)

Adolphsen, C.E.; Lavine, T.L.; Atwood, W.B.

1989-03-01

Misalignment of quadrupole magnets and beam position monitors (BPMs) in the linac of the SLAC Linear Collider (SLC) cause the electron and positron beams to be steered off-center in the disk-loaded waveguide accelerator structures. Off-center beams produce wakefields which limit the SLC performance at high beam intensities by causing emittance growth. Here, we present a general method for simultaneously determining quadrupole magnet and BPM offsets using beam trajectory measurements. Results from the application of the method to the SLC linac are described. The alignment precision achieved is approximately 100 μm, which is significantly better than that obtained using optical surveying techniques. 2 refs., 4 figs

A technique for aligning sextupole systems using beam optics

International Nuclear Information System (INIS)

Chao, Yu-Chiu.

1992-03-01

A technique for beam based alignment of sextupole system is developed exploiting the enhancement effect of orbit differences by the sextupoles. This technique can in principle be applied to sextupole or sextupole strings with controlled orbit pattern and BPM configurations. This paper will discuss the theoretical basis, special optimization considerations and expected accuracy. Application to the SLC final focus is also discussed

Atomic layer deposition of HfO{sub 2} on graphene through controlled ion beam treatment

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki Seok [School of Advanced Materials Science and Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419 (Korea, Republic of); Oh, Il-Kwon; Jung, Hanearl; Kim, Hyungjun [School of Electrical and Electronics Engineering, Yonsei University, 50 Yonsei Ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Yeom, Geun Young, E-mail: knam1004@dju.kr, E-mail: gyyeom@skku.edu [School of Advanced Materials Science and Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419 (Korea, Republic of); Kim, Kyong Nam, E-mail: knam1004@dju.kr, E-mail: gyyeom@skku.edu [School of Advanced Materials Science and Engineering, Daejeon University, Yongun-dong, Dong-gu, Daejeon 34520 (Korea, Republic of)

2016-05-23

The polymer residue generated during the graphene transfer process to the substrate tends to cause problems (e.g., a decrease in electron mobility, unwanted doping, and non-uniform deposition of the dielectric material). In this study, by using a controllable low-energy Ar{sup +} ion beam, we cleaned the polymer residue without damaging the graphene network. HfO{sub 2} grown by atomic layer deposition on graphene cleaned using an Ar{sup +} ion beam showed a dense uniform structure, whereas that grown on the transferred graphene (before Ar{sup +} ion cleaning) showed a non-uniform structure. A graphene–HfO{sub 2}–metal capacitor fabricated by growing 20-nm thick HfO{sub 2} on graphene exhibited a very low leakage current (<10{sup −11} A/cm{sup 2}) for Ar{sup +} ion-cleaned graphene, whereas a similar capacitor grown using the transferred graphene showed high leakage current.

Fabrication of highly oriented β-FeSi2 by ion beam sputter deposition

International Nuclear Information System (INIS)

Nakanoya, Takamitsu; Sasase, Masato; Yamamoto, Hiroyuki; Saito, Takeru; Hojou, Kiichi

2002-01-01

We have prepared the 'environmentally friendly' semiconductor, β-FeSi 2 thin films by ion beam sputter deposition method. The temperature of Si (100) substrate during the deposition and total amount of deposited Fe have been changed in order to find the optimum condition of the film formation. The crystallinity and surface morphology of the formed silicides were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. It is understood that the domain of the epitaxially grown β-FeSi 2 increases with the substrate temperature up to 700degC at the fixed amount of deposited Fe (33 nm) by XRD spectra. On the other hand, α-FeSi 2 is appeared and increased with the temperature above 700degC. Granulation of the surface is also observed by SEM images at this temperature region. At the fixed temperature condition (700degC), formation of α phase, which is obtained at the higher temperature compared with β phase, is observed for the fewer deposited samples. These results suggest the possibility of the epitaxially grown β-FeSi 2 formation at the lower (< 700degC) temperature region. (author)

ZrN coatings deposited by high power impulse magnetron sputtering and cathodic arc techniques

Energy Technology Data Exchange (ETDEWEB)

Purandare, Yashodhan, E-mail: Y.Purandare@shu.ac.uk; Ehiasarian, Arutiun; Hovsepian, Papken [Nanotechnology Centre for PVD Research, Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom); Santana, Antonio [Ionbond AG Olten, Industriestrasse 211, CH-4600 Olten (Switzerland)

2014-05-15

Zirconium nitride (ZrN) coatings were deposited on 1 μm finish high speed steel and 316L stainless steel test coupons. Cathodic Arc (CA) and High Power Impulse Magnetron Sputtering (HIPIMS) + Unbalanced Magnetron Sputtering (UBM) techniques were utilized to deposit coatings. CA plasmas are known to be rich in metal and gas ions of the depositing species as well as macroparticles (droplets) emitted from the arc sports. Combining HIPIMS technique with UBM in the same deposition process facilitated increased ion bombardment on the depositing species during coating growth maintaining high deposition rate. Prior to coating deposition, substrates were pretreated with Zr{sup +} rich plasma, for both arc deposited and HIPIMS deposited coatings, which led to a very high scratch adhesion value (L{sub C2}) of 100 N. Characterization results revealed the overall thickness of the coatings in the range of 2.5 μm with hardness in the range of 30–40 GPa depending on the deposition technique. Cross-sectional transmission electron microscopy and tribological experiments such as dry sliding wear tests and corrosion studies have been utilized to study the effects of ion bombardment on the structure and properties of these coatings. In all the cases, HIPIMS assisted UBM deposited coating fared equal or better than the arc deposited coatings, the reasons being discussed in this paper. Thus H+U coatings provide a good alternative to arc deposited where smooth, dense coatings are required and macrodroplets cannot be tolerated.

Multi-beam backscatter image data processing techniques employed to EM 1002 system

Digital Repository Service at National Institute of Oceanography (India)

Fernandes, W.A.; Chakraborty, B.

to compensate outer-beam backscatter strength data in such a way that the effect of angular backscatter strength is removed. In this work we have developed backscatter data processing techniques for EM1002 multi-beam system...

Beam shaping optics to enhance performance of interferometry techniques in grating manufacture

Science.gov (United States)

Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei

2018-02-01

Improving of industrial holographic and interferometry techniques is of great importance in interference lithography, computer-generated holography, holographic data storage, interferometry recording of Bragg gratings as well as gratings of various types in semiconductor industry. Performance of mentioned techniques is essentially enhanced by providing a light beam with flat phase front and flat-top irradiance distribution. Therefore, transformation of Gaussian distribution of a TEM00 laser to flat-top (top hat, uniform) distribution is an important optical task. There are different refractive and diffractive beam shaping approaches used in laser industrial and scientific applications, but only few of them are capable to fulfil the optimum conditions for beam quality demanding holography and interferometry. As a solution it is suggested to apply refractive field mapping beam shaping optics πShaper, which operational principle presumes almost lossless transformation of Gaussian to flat-top beam with flatness of output wavefront, conserving of beam consistency, providing collimated low divergent output beam, high transmittance, extended depth of field, negligible wave aberration, and achromatic design provides capability to work with several lasers with different wavelengths simultaneously. High optical quality of resulting flat-top beam allows applying additional optical components to build various imaging optical systems for variation of beam size and shape to fulfil requirements of a particular application. This paper will describe design basics of refractive beam shapers and optical layouts of their applying in holography and laser interference lithography. Examples of real implementations and experimental results will be presented as well.

In situ analysis of thin film deposition processes using time-of-flight (TOF) ion beam analysis methods

International Nuclear Information System (INIS)

Im, J.; Lin, Y.; Schultz, J.A.; Auciello, O.H.; Chang, R.P.H.

1995-05-01

Non-destructive, in situ methods for characterization of thin film growth phenomena is key to understand thin film growth processes and to develop more reliable deposition procedures, especially for complex layered structures involving multi-phase materials. However, surface characterization methods that use either electrons (e.g. AES or XPS) or low energy ions (SIMS) require an UHV environment and utilize instrumentation which obstructs line of sight access to the substrate and are therefore incompatible with line of sight deposition methods and thin film deposition processes which introduce gas, either part of the deposition or in order to produce the desired phase. We have developed a means of differentially pumping both the ion beam source and detectors of a TOF ion beam surface analysis spectrometer that does not interfere with the deposition process and permits compositional and structural analysis of the growing film in the present system, at pressures up to several mTorr. Higher pressures are feasible with modified source-detector geometry. In order to quantify the sensitivity of Ion Scattering Spectroscopy (ISS) and Direct Recoil Spectroscopy (DRS), we have measured the signal intensity for stabilized clean metals in a variety of gas environments as a function of the ambient gas species and pressure, and ion beam species and kinetic energy. Results are interpreted in terms of collision cross sections which are compared with known gas phase scattering data and provide an apriori basis for the evaluation of time-of-flight ion scattering and recoil spectroscopies (ToF-ISARS) for various industrial processing environments which involve both inert and reactive cases. The cross section data for primary ion-gas molecule and recoiled atom-gas molecule interactions are also provided. from which the maximum operating pressure in any experimental configuration can be obtained

Energy Deposition in Adjacent LHC Superconducting Magnets from Beam Loss at LHC Transfer Line Collimators

CERN Document Server

Beavan, S; Kain, V

2006-01-01

Injection intensities for the LHC are over an order of magnitude above the damage threshold. The collimation system in the two transfer lines is designed to dilute the beam sufficiently to avoid damage in case of accidental beam loss or mis-steered beam. To maximise the protection for the LHC most of the collimators are located in the last 300 m upstream of the injection point where the transfer lines approach the LHC machine. To study the issue of possible quenches following beam loss at the collimators part of the collimation section in one of the lines, TI 8, together with the adjacent part of the LHC has been modeled in FLUKA. The simulated energy deposition in the LHC for worst-case accidental losses and as well as for losses expected during a normal filling is presented.

Physical Vapor Deposition of Thin Films

Science.gov (United States)

Mahan, John E.

2000-01-01

A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

Growth modes and epitaxy of FeAl thin films on a-cut sapphire prepared by pulsed laser and ion beam assisted deposition

Energy Technology Data Exchange (ETDEWEB)

Yao, Xiang; Trautvetter, Moritz; Ziemann, Paul [Institut für Festkörperphysik, Universität Ulm, Albert-Einstein-Allee 11, 89069 Ulm (Germany); Wiedwald, Ulf [Institut für Festkörperphysik, Universität Ulm, Albert-Einstein-Allee 11, 89069 Ulm (Germany); Fakultät für Physik, Universität Duisburg-Essen, Lotharstraße 1, 47057 Duisburg (Germany)

2014-01-14

FeAl films around equiatomic composition are grown on a-cut (112{sup ¯}0) sapphire substrates by ion beam assisted deposition (IBAD) and pulsed laser deposition (PLD) at ambient temperature. Subsequent successive annealing is used to establish chemical order and crystallographic orientation of the films with respect to the substrate. We find a strongly [110]-textured growth for both deposition techniques. Pole figures prove the successful preparation of high quality epitaxial films by PLD with a single in-plane orientation. IBAD-grown films, however, exhibit three in-plane orientations, all of them with broad angular distributions. The difference of the two growth modes is attributed to the existence of a metastable intermediate crystalline orientation as concluded from nonassisted sputter depositions at different substrate temperatures. The formation of the chemically ordered crystalline B2 phase is accompanied by the expected transition from ferromagnetic to paramagnetic behavior of the films. In accordance with the different thermally induced structural recovery, we find a step-like magnetic transition to paramagnetic behavior after annealing for 1 h at T{sub A} = 300 °C for IBAD deposition, while PLD-grown films show a gradual decrease of ferromagnetic signals with rising annealing temperatures.

Energy deposition studies for the LBNE beam absorber

International Nuclear Information System (INIS)

Rakhno, Igor L.; Mokhov, Nikolai V.; Tropin, Igor S.

2015-01-01

Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system - all with corresponding radiation shielding - was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options. (authors)

Thermal conductivity and nanocrystalline structure of platinum deposited by focused ion beam

KAUST Repository

Alaie, Seyedhamidreza

2015-02-04

Pt deposited by focused ion beam (FIB) is a common material used for attachment of nanosamples, repair of integrated circuits, and synthesis of nanostructures. Despite its common use little information is available on its thermal properties. In this work, Pt deposited by FIB is characterized thermally, structurally, and chemically. Its thermal conductivity is found to be substantially lower than the bulk value of Pt, 7.2 W m-1 K-1 versus 71.6 W m-1 K-1 at room temperature. The low thermal conductivity is attributed to the nanostructure of the material and its chemical composition. Pt deposited by FIB is shown, via aberration corrected TEM, to be a segregated mix of nanocrystalline Pt and amorphous C with Ga and O impurities. Ga impurities mainly reside in the Pt while O is homogeneously distributed throughout. The Ga impurity, small grain size of the Pt, and the amorphous carbon between grains are the cause for the low thermal conductivity of this material. Since Pt deposited by FIB is a common material for affixing samples, this information can be used to assess systematic errors in thermal characterization of different nanosamples. This application is also demonstrated by thermal characterization of two carbon nanofibers and a correction using the reported thermal properties of the Pt deposited by FIB.

The role of electron-stimulated desorption in focused electron beam induced deposition

DEFF Research Database (Denmark)

van Dorp, Willem F.; Hansen, Thomas Willum; Wagner, Jakob Birkedal

2013-01-01

We present the results of our study about the deposition rate of focused electron beam induced processing (FEBIP) as a function of the substrate temperature with the substrate being an electron-transparent amorphous carbon membrane. When W(CO)6 is used as a precursor it is observed that the growt......, the majority desorbs from the surface rather than dissociates to contribute to the deposit. It is important to take this into account during FEBIP experiments, for instance when determining fundamental process parameters such as the activation energy for desorption....... experiments compared to literature values is consistent with earlier findings by other authors. The discrepancy is attributed to electron-stimulated desorption, which is known to occur during electron irradiation. The data suggest that, of the W(CO)6 molecules that are affected by the electron irradiation...

Large flexibility of high aspect ratio carbon nanostructures fabricated by electron-beam-induced deposition

Energy Technology Data Exchange (ETDEWEB)

Beard, J D; Gordeev, S N, E-mail: jdb28@bath.ac.uk [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)

2010-11-26

The mechanical properties of free-standing electron beam deposited amorphous carbon structures have been studied using atomic force microscopy. The fabricated carbon blades are found to be extraordinarily flexible, capable of undergoing vertical deflection up to {approx} 75% of their total length without inelastic deformation. The elastic bending modulus of these structures was calculated to be 28 {+-} 10 GPa.

Verification and application of beam steering Phased Array UT technique for complex structures

International Nuclear Information System (INIS)

Yamamoto, Setsu; Miura, Takahiro; Semboshi, Jun; Ochiai, Makoto; Mitsuhashi, Tadahiro; Adachi, Hiroyuki; Yamamoto, Satoshi

2013-01-01

Phased Array Ultrasonic Testing (PAUT) techniques for complex geometries are greatly progressing. We developed an immersion PAUT which is suitable for complex surface profiles such as nozzles and deformed welded areas. Furthermore, we have developed a shape adaptive beam steering technique for 3D complex surface structures with conventional array probe and flexible coupling gel which makes the immersion beam forming technique usable under dry conditions. This system consists of 3 steps. Step1 is surface profile measurement which based on 3D Synthesis Aperture Focusing Technique (SAFT), Step2 is delay law calculation which could take into account the measured 3D surface profiles and steer a shape adjusted ultrasonic beam, Step3 is shape adjusted B-scope construction. In this paper, verification results of property of this PAUT system using R60 curved specimen and nozzle shaped specimen which simulated actual BWR structure. (author)

Electron beam instrumentation techniques using coherent radiation

International Nuclear Information System (INIS)

Wang, D.X.

1997-01-01

Much progress has been made on coherent radiation research since coherent synchrotron radiation was first observed in 1989. The use of coherent radiation as a bunch length diagnostic tool has been studied by several groups. In this paper, brief introductions to coherent radiation and far-infrared measurement are given, the progress and status of their beam diagnostic application are reviewed, different techniques are described, and their advantages and limitations are discussed

Visible light active TiO2 films prepared by electron beam deposition of noble metals

International Nuclear Information System (INIS)

Hou Xinggang; Ma Jun; Liu Andong; Li Dejun; Huang Meidong; Deng Xiangyun

2010-01-01

TiO 2 films prepared by sol-gel method were modified by electron beam deposition of noble metals (Pt, Pd, and Ag). Effects of noble metals on the chemical and surface characteristics of the films were studied using XPS, TEM and UV-Vis spectroscopy techniques. Photocatalytic activity of modified TiO 2 films was evaluated by studying the degradation of methyl orange dye solution under visible light UV irradiation. The result of TEM reveals that most of the surface area of TiO 2 is covered by tiny particles of noble metals with diameter less than 1 nm. Broad red shift of UV-Visible absorption band of modified photocatalysts was observed. The catalytic degradation of methyl orange in aqueous solutions under visible light illumination demonstrates a significant enhancement of photocatalytic activity of these films compared with the un-loaded films. The photocatalytic efficiency of modified TiO 2 films by this method is affected by the concentration of impregnating solution.

Comparison of the Al back contact deposited by sputtering, e-beam, or thermal evaporation for inverted perovskite solar cells

Science.gov (United States)

Wahl, Tina; Hanisch, Jonas; Ahlswede, Erik

2018-04-01

In this work, we present inverted perovskite solar cells with Al top electrodes, which were deposited by three different methods. Besides the widely used thermal evaporation of Al, we also used the industrially important high deposition rate processes sputtering and electron beam evaporation for aluminium electrodes and examined the influence of the deposition method on the solar cell performance. The current-voltage characteristics of as grown solar cells with sputtered and e-beam Al electrode show an s-shape due to damage done to the organic electronic transport layers (ETL) during Al deposition. It can be cured by a short annealing step at a moderate temperature so that fill factors  >60% and power conversion efficiencies of almost 12% with negligible hysteresis can be achieved. While solar cells with thermally evaporated Al electrode do not show an s-shape, they also exhibit a clear improvement after a short annealing step. In addition, we varied the thickness of the ETL consisting of a double layer ([6,6]-Phenyl-C61-butyric acid methyl ester and bathocuproine) and investigated the influence on the solar cell parameters for the three different Al deposition methods, which showed distinct dependencies on ETL thickness.

Results of the studies on energy deposition in IR6 superconducting magnets from continuous beam loss on the TCDQ system

CERN Document Server

Bracco, C; Presland, A; Redaelli, S; Sarchiapone, L; Weiler, T

2007-01-01

A single sided mobile graphite diluter block TCDQ, in combination with a two-sided secondary collimator TCS and an iron shield TCDQM, will be installed in front of the superconducting quadrupole Q4 magnets in IR6, in order to protect it and other downstream LHC machine elements from destruction in the event of a beam dump that is not synchronised with the abort gap. The TCDQ will be positioned close to the beam, and will intercept the particles from the secondary halo during low beam lifetime. Previous studies (1-4) have shown that the energy deposited in the Q4 magnet coils can be close to or above the quench limit. In this note the results of the latest FLUKA energy deposition simulations for Beam 2 are described, including an upgrade possibility for the TCDQ system with an additional shielding device. The results are discussed in the context of the expected performance levels for the different phases of LHC operation.

Adhesion-enhanced thick copper film deposition on aluminum oxide by an ion-beam-mixed Al seed layer

International Nuclear Information System (INIS)

Kim, Hyung-Jin; Park, Jae-Won

2012-01-01

We report a highly-adherent 30-μm Cu conductive-path coating on an aluminum-oxide layer anodized on an aluminum-alloy substrate for a metal-printed circuit-board application. A 50-nm Al layer was first coated with an e-beam evaporative deposition method on the anodized oxide, followed by ion bombardment to mix the interfacial region. Subsequently, a Cu coating was deposited onto the mixed seed layer to the designed thickness. Adhesions of the interface were tested by using tape adhesion test, and pull-off tests and showed commercially acceptable adhesions for such thick coating layers. The ion beam mixing (IBM) plays the role of fastening the thin seed coating layer to the substrate and enhancing the adhesion of the Cu conductive path on the anodized aluminum surface.

All-optical optoacoustic microscopy based on probe beam deflection technique

OpenAIRE

Maswadi, Saher M.; Ibey, Bennett L.; Roth, Caleb C.; Tsyboulski, Dmitri A.; Beier, Hope T.; Glickman, Randolph D.; Oraevsky, Alexander A.

2016-01-01

Optoacoustic (OA) microscopy using an all-optical system based on the probe beam deflection technique (PBDT) for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i) efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii) undistorted coupling of acoustic waves to the detector without the need for separa...

Electrochemical impedance spectroscopy on nanostructured carbon electrodes grown by supersonic cluster beam deposition

International Nuclear Information System (INIS)

Bettini, Luca Giacomo; Bardizza, Giorgio; Podestà, Alessandro; Milani, Paolo; Piseri, Paolo

2013-01-01

Nanostructured porous films of carbon with density of about 0.5 g/cm 3 and 200 nm thickness were deposited at room temperature by supersonic cluster beam deposition (SCBD) from carbon clusters formed in the gas phase. Carbon film surface topography, determined by atomic force microscopy, reveals a surface roughness of 16 nm and a granular morphology arising from the low kinetic energy ballistic deposition regime. The material is characterized by a highly disordered carbon structure with predominant sp2 hybridization as evidenced by Raman spectroscopy. The interface properties of nanostructured carbon electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy employing KOH 1 M solution as aqueous electrolyte. An increase of the double layer capacitance is observed when the electrodes are heat treated in air or when a nanostructured nickel layer deposited by SCBD on top of a sputter deposited film of the same metal is employed as a current collector instead of a plain metallic film. This enhancement is consistent with an improved charge injection in the active material and is ascribed to the modification of the electrical contact at the interface between the carbon and the metal current collector. Specific capacitance values up to 120 F/g have been measured for the electrodes with nanostructured metal/carbon interface.

Electrochemical impedance spectroscopy on nanostructured carbon electrodes grown by supersonic cluster beam deposition

Energy Technology Data Exchange (ETDEWEB)

Bettini, Luca Giacomo; Bardizza, Giorgio; Podesta, Alessandro; Milani, Paolo; Piseri, Paolo, E-mail: piseri@mi.infn.it [Universita degli Studi di Milano, Dipartimento di Fisica and CIMaINa (Italy)

2013-02-15

Nanostructured porous films of carbon with density of about 0.5 g/cm{sup 3} and 200 nm thickness were deposited at room temperature by supersonic cluster beam deposition (SCBD) from carbon clusters formed in the gas phase. Carbon film surface topography, determined by atomic force microscopy, reveals a surface roughness of 16 nm and a granular morphology arising from the low kinetic energy ballistic deposition regime. The material is characterized by a highly disordered carbon structure with predominant sp2 hybridization as evidenced by Raman spectroscopy. The interface properties of nanostructured carbon electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy employing KOH 1 M solution as aqueous electrolyte. An increase of the double layer capacitance is observed when the electrodes are heat treated in air or when a nanostructured nickel layer deposited by SCBD on top of a sputter deposited film of the same metal is employed as a current collector instead of a plain metallic film. This enhancement is consistent with an improved charge injection in the active material and is ascribed to the modification of the electrical contact at the interface between the carbon and the metal current collector. Specific capacitance values up to 120 F/g have been measured for the electrodes with nanostructured metal/carbon interface.

Electrochemical impedance spectroscopy on nanostructured carbon electrodes grown by supersonic cluster beam deposition

Science.gov (United States)

Bettini, Luca Giacomo; Bardizza, Giorgio; Podestà, Alessandro; Milani, Paolo; Piseri, Paolo

2013-02-01

Nanostructured porous films of carbon with density of about 0.5 g/cm3 and 200 nm thickness were deposited at room temperature by supersonic cluster beam deposition (SCBD) from carbon clusters formed in the gas phase. Carbon film surface topography, determined by atomic force microscopy, reveals a surface roughness of 16 nm and a granular morphology arising from the low kinetic energy ballistic deposition regime. The material is characterized by a highly disordered carbon structure with predominant sp2 hybridization as evidenced by Raman spectroscopy. The interface properties of nanostructured carbon electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy employing KOH 1 M solution as aqueous electrolyte. An increase of the double layer capacitance is observed when the electrodes are heat treated in air or when a nanostructured nickel layer deposited by SCBD on top of a sputter deposited film of the same metal is employed as a current collector instead of a plain metallic film. This enhancement is consistent with an improved charge injection in the active material and is ascribed to the modification of the electrical contact at the interface between the carbon and the metal current collector. Specific capacitance values up to 120 F/g have been measured for the electrodes with nanostructured metal/carbon interface.

Obtention of thin depositions by the vacuum evaporation technique

International Nuclear Information System (INIS)

Gonzalez Mateu, D.; Labrada, A.; Voronin, A.

1991-01-01

The vacuum evaporating technique used to prepare thin depositions, and the technical characteristics of the constructed installation are described. 235 U y 238 U nuclear target for the fission researches were obtained. Aluminium and gold self-supporting foils were obtained too

Study on the electrical and optical properties of Ag/Al-doped ZnO coatings deposited by electron beam evaporation

International Nuclear Information System (INIS)

Sahu, D.R.; Lin, S.-Y.; Huang, J.-L.

2007-01-01

A layer of silver was deposited onto the surface of glass substrates, coated with AZO (Al-doped ZnO), to form Ag/AZO film structures, using e-beam evaporation techniques. The electrical and optical properties of AZO, Ag and Ag/AZO film structures were studied. The deposition of Ag layer on the surface of AZO films resulted in lowering the effective electrical resistivity with a slight reduction of their optical transmittance. Ag (11 nm)/AZO (25 nm) film structure, with an accuracy of ±0.5 nm for the thickness shows a sheet resistance as low as 5.6 ± 0.5 Ω/sq and a transmittance of about 66 ± 2%. A coating consisting of AZO (25 nm)/Ag (11 nm)/AZO (25 nm) trilayer structure, exhibits a resistance of 7.7 ± 0.5 Ω/sq and a high transmittance of 85 ± 2%. The coatings have satisfactory properties of low resistance, high transmittance and highest figure of merit for application in optoelectronics devices including flat displays, thin films transistors and solar cells as transparent conductive electrodes

Mechanical and tribological properties of carbon thin film with tungsten interlayer prepared by Ion beam assisted deposition

Czech Academy of Sciences Publication Activity Database

Vlčák, P.; Černý, F.; Tolde, Z.; Sepitka, J.; Gregora, Ivan; Daniš, S.

2013-01-01

Roč. 2013, FEB (2013) ISSN 2314-4874 Institutional support: RVO:68378271 Keywords : carbon coatings * ion beam deposition * XRD * nanoindentation Subject RIV: BM - Solid Matter Physics ; Magnetism http://dx.doi.org/10.1155/2013/630156

Improved stability of organic light-emitting diode with aluminum cathodes prepared by ion beam assisted deposition

Directory of Open Access Journals (Sweden)

Soon Moon Jeong, Deuk Yeon Lee, Won Hoe Koo, Sang Hun Choi, Hong Koo Baik, Se-Jong Lee and Kie Moon Song

2005-01-01

Full Text Available We have fabricated highly stable organic electroluminescent devices based on spin-coated poly-p-phenylene-vynylene (PPV thin films. The electrical properties of aluminum cathode, prepared by ion beam assisted deposition, on PPV have been investigated and compared to those by thermal evaporation. Although energetic particles of Al assisted by Ar+ ion may damage the organic material, I–V–L characteristics are improved by applying thin Al buffer layer. In addition, a dense Al cathode inhibits the permeation of H2O and O2 into PPV film through pinhole defects, and thus retards dark spot growth. It may be deduced from highly packed structure of Al cathode with an increase in the contact area between Al and PPV that reduce the contact resistance. In conclusion, the lifetime of organic light-emitting device (OLED has been extended effectively by dense Al film through ion beam assisted deposition process.

Properties of amorphous silicon thin films synthesized by reactive particle beam assisted chemical vapor deposition

International Nuclear Information System (INIS)

Choi, Sun Gyu; Wang, Seok-Joo; Park, Hyeong-Ho; Jang, Jin-Nyoung; Hong, MunPyo; Kwon, Kwang-Ho; Park, Hyung-Ho

2010-01-01

Amorphous silicon thin films were formed by chemical vapor deposition of reactive particle beam assisted inductively coupled plasma type with various reflector bias voltages. During the deposition, the substrate was heated at 150 o C. The effects of reflector bias voltage on the physical and chemical properties of the films were systematically studied. X-ray diffraction and Raman spectroscopy results showed that the deposited films were amorphous and the films under higher reflector voltage had higher internal energy to be easily crystallized. The chemical state of amorphous silicon films was revealed as metallic bonding of Si atoms by using X-ray photoelectron spectroscopy. An increase in reflector voltage induced an increase of surface morphology of films and optical bandgap and a decrease of photoconductivity.

ITO/InP solar cells: A comparison of devices fabricated by ion beam and RF sputtering of the ITO

Science.gov (United States)

Coutts, T. J.

1987-01-01

This work was performed with the view of elucidating the behavior of indium tin oxide/indium phosphide (ITO/InP) solar cells prepared by RF and ion beam sputtering. It was found that using RF sputter deposition of the ITO always leads to more efficient devices than ion beam sputter deposition. An important aspect of the former technique is the exposure of the single crystal p-InP substrates to a very low plasma power prior to deposition. Substrates treated in this manner have also been used for ion beam deposition of ITO. In this case the cells behave very similarly to the RF deposited cells, thus suggesting that the lower power plasma exposure (LPPE) is the crucial process step.

A comparative study of CdS thin films deposited by different techniques

Energy Technology Data Exchange (ETDEWEB)

Pérez-Hernández, G., E-mail: german.perez@ujat.mx [Universidad Juárez Autónoma de Tabasco, Avenida Universidad s/n, Col. Magisterial, Villahermosa, Tabasco 86040 (Mexico); Pantoja-Enríquez, J. [Centro de Investigación y Desarrollo Tecnológico en Energías Renovables, UNICACH, Libramiento Norte No 1150, Tuxtla Gutiérrez, Chiapas 29039 (Mexico); Escobar-Morales, B. [Instituto Tecnológico de Cancún, Avenida Kábah Km 3, Cancún, Quintana Roo 77500 (Mexico); Martinez-Hernández, D.; Díaz-Flores, L.L.; Ricardez-Jiménez, C. [Universidad Juárez Autónoma de Tabasco, Avenida Universidad s/n, Col. Magisterial, Villahermosa, Tabasco 86040 (Mexico); Mathews, N.R.; Mathew, X. [Centro de Investigación en Energía, Universidad Nacional Autónoma de México, Temixco, Morelos 62580 (Mexico)

2013-05-01

Cadmium sulfide thin-films were deposited on glass slides and SnO{sub 2}:F coated glass substrates by chemical bath deposition, sputtering and close-spaced sublimation techniques. The films were studied for the structural and opto-electronic properties after annealing in an ambient identical to that employed in the fabrication of CdTe/CdS devices. Quantum efficiency of the CdTe/CdS solar cells fabricated with CdS buffer films prepared by the three methods were investigated to understand the role of CdS film preparation method on the blue response of the devices. The higher blue response observed for the devices fabricated with chemical bath deposited CdS film is discussed. - Highlights: ► CdS films were prepared by different techniques. ► Role of CdS on the blue response of device was studied. ► Structural and optical properties of CdS were analyzed. ► Chemically deposited CdS has high blue transmittance. ► CdS deposition method influences diffusion of S and Te.

Optical band gap of ZnO thin films deposited by electron beam evaporation

International Nuclear Information System (INIS)

Nadeem, M. Y.; Ali, S. L.; Wasiq, M. F.; Rana, A. M.

2006-01-01

Optical band gap of ZnO thin films deposited by electron beam evaporation at evaporation rates ranging 5 As/sup -1/ to 15 As /sup -1/ and thickness ranging 1000A to 3000A is presented. Deposited films were annealed at 573K for one and half hour. The variations in the optical band gap were observed and showed decreasing behavior from 3.15 eV, 3.05 eV, from 3.18 eV to 3.10 eV and from 3.19 eV to 3.18 eV for films with respective thickness 1000A, 2000 A, 3000 A on increasing the evaporation rate from 5 As/sup-1/ to As/sup -1/ by keeping thickness constant. (author)

Crystal structure of TiNi nanoparticles obtained by Ar ion beam deposition

International Nuclear Information System (INIS)

Castro, A. Torres; Cuellar, E. Lopez; Mendez, U. Ortiz; Yacaman, M. Jose

2008-01-01

Nanoparticles are a state of matter that have properties different from either molecules or bulk solids, turning them into a very interesting class of materials to study. In the present work, the crystal structure of TiNi nanoparticles obtained by ion beam deposition is characterized. TiNi nanoparticles were obtained from TiNi wire samples by sputtering with Ar ions using a Gatan precision ion polishing system. The TiNi nanoparticles were deposited on a Lacey carbon film that was used for characterization by transmission electron microscopy. The nanoparticles were characterized by high-resolution transmission electron microscopy, high-angle annular dark-field imaging, electron diffraction, scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy. Results of nanodiffraction seem to indicate that the nanoparticles keep the same B2 crystal structure as the bulk material but with a decreased lattice parameter

TOF technique for laser-driven proton beam diagnostics for the ELIMED beamline

International Nuclear Information System (INIS)

Milluzzo, G.; Scuderi, V.; Amico, A.G.; Cirrone, G.A.P.; Cuttone, G.; Larosa, G.; Leanza, R.; Petringa, G.; Pipek, J.; Romano, F.; Napoli, M. De; Dostal, J.; Margarone, D.; Schillaci, F.; Velyhan, A.

2017-01-01

The Time of Flight (TOF) method for laser-driven ion beam diagnostics has been extensively investigated so far for low energy ion diagnostics and several works, reported in literature [1,2], have shown its efficiency in the measurement of particle beam characteristics such as ion species, energy spectrum and current. Moreover, such technique allows obtaining a shot-to-shot on-line monitoring of optically accelerated particles, necessary to control the reproducibility of the accelerated beam and to deliver a beam suitable for any kind of applications. For this reason, the ELIMED beamline [3,4], which will be entirely developed at INFN-LNS and installed in 2017 within the ion beamline ELIMAIA (ELI Multidisciplinary Applications of laser-Ion Acceleration) experimental hall at ELI-Beamlines in Prague, will be equipped with an on-line diagnostics system composed by silicon carbide and diamond detectors, using the TOF technique. In this contribution, the procedure developed for TOF signal analysis will be briefly reported.

A review of hydroxyapatite-based coating techniques: Sol-gel and electrochemical depositions on biocompatible metals.

Science.gov (United States)

Asri, R I M; Harun, W S W; Hassan, M A; Ghani, S A C; Buyong, Z

2016-04-01

New promising techniques for depositing biocompatible hydroxyapatite-based coatings on biocompatible metal substrates for biomedical applications have continuously been exploited for more than two decades. Currently, various experimental deposition processes have been employed. In this review, the two most frequently used deposition processes will be discussed: a sol-gel dip coating and an electrochemical deposition. This study deliberates the surface morphologies and chemical composition, mechanical performance and biological responses of sol-gel dip coating as well as the electrochemical deposition for two different sample conditions, with and without coating. The review shows that sol-gel dip coatings and electrochemical deposition were able to obtain the uniform and homogeneous coating thickness and high adherent biocompatible coatings even in complex shapes. It has been accepted that both coating techniques improve bone strength and initial osseointegration rate. The main advantages and limitations of those techniques of hydroxyapatite-based coatings are presented. Furthermore, the most significant challenges and critical issues are also highlighted. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structural characterization of the nickel thin film deposited by glad technique

Directory of Open Access Journals (Sweden)

Potočnik J.

2013-01-01

Full Text Available In this work, a columnar structure of nickel thin film has been obtained using an advanced deposition technique known as Glancing Angle Deposition. Nickel thin film was deposited on glass sample at the constant emission current of 100 mA. Glass sample was positioned 15 degrees with respect to the nickel vapor flux. The obtained nickel thin film was characterized by Force Modulation Atomic Force Microscopy and by Scanning Electron Microscopy. Analysis indicated that the formation of the columnar structure occurred at the film thickness of 1 μm, which was achieved for the deposition time of 3 hours. [Projekat Ministarstva nauke Republike Srbije, br. III45005

Effect of deposition distance on thickness and microstructure of silicon thin film produced by electron beam evaporation; Efeito da distancia de deposicao na espessura e microestrutura de filme fino obtido por evaporacao por feixe de eletrons

Energy Technology Data Exchange (ETDEWEB)

Toledo, T.F.; Ramanery, F.P.; Branco, J.R.T. [Fundacao Centro Tecnologico de Minas Gerais, Belo Horizonte, MG (Brazil)], e-mail: thalitaqui@yahoo.com.br; Cunha, M.A. [Acos Especiais Itabira S.A. (Acesita), Belo Horizonte, MG (Brazil)

2006-07-01

The interest for materials with new characteristics and properties made thin films an area of highest research interest. Silicon thin films have been widely used in solar cells, being the main active layer. In this work, the effect of deposition distance on thickness and microstructure of silicon films was investigated. The electron beam evaporation technique with argon plasma assistance was used to obtain films on stainless steel 304, Fe-Si alloy and soda lime glass. The experiments were made varying electron beam current and deposition pressure. The results are discussed based on Hertz-Knudsen's law and thin films microstructure evolution models. The samples were characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction and profilometer. (author)

Automation of neutral beam source conditioning with artificial intelligence techniques

International Nuclear Information System (INIS)

Johnson, R.R.; Canales, T.W.; Lager, D.L.

1985-01-01

This paper describes a system that automates neutral beam source conditioning. The system achieves this with artificial intelligence techniques. The architecture of the system is presented followed by a description of its performance

Automation of neutral beam source conditioning with artificial intelligence techniques

International Nuclear Information System (INIS)

Johnson, R.R.; Canales, T.; Lager, D.

1986-01-01

This paper describes a system that automates neutral beam source conditioning. The system achieves this with artificial intelligence techniques. The architecture of the system is presented followed by a description of its performance

Effect of deposition rate on the microstructure of electron beam evaporated nanocrystalline palladium thin films

Energy Technology Data Exchange (ETDEWEB)

Amin-Ahmadi, B., E-mail: behnam.amin-ahmadi@ua.ac.be [Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Idrissi, H. [Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Galceran, M. [Université Libre de Bruxelles, Matters and Materials Department, 50 Av. FD Roosevelt CP194/03, 1050 Brussels (Belgium); Colla, M.S. [Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-la-Neuve (Belgium); Raskin, J.P. [Information and Communications Technologies, Electronics and Applied Mathematics (ICTEAM), Microwave Laboratory, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Pardoen, T. [Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-la-Neuve (Belgium); Godet, S. [Université Libre de Bruxelles, Matters and Materials Department, 50 Av. FD Roosevelt CP194/03, 1050 Brussels (Belgium); Schryvers, D. [Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

2013-07-31

The influence of the deposition rate on the formation of growth twins in nanocrystalline Pd films deposited by electron beam evaporation is investigated using transmission electron microscopy. Statistical measurements prove that twin boundary (TB) density and volume fraction of grains containing twins increase with increasing deposition rate. A clear increase of the dislocation density was observed for the highest deposition rate of 5 Å/s, caused by the increase of the internal stress building up during deposition. Based on crystallographic orientation indexation using transmission electron microscopy, it can be concluded that a {111} crystallographic texture increases with increasing deposition rate even though the {101} crystallographic texture remains dominant. Most of the TBs are fully coherent without any residual dislocations. However, for the highest deposition rate (5 Å/s), the coherency of the TBs decreases significantly as a result of the interaction of lattice dislocations emitted during deposition with the growth TBs. The analysis of the grain boundary character of different Pd films shows that an increasing fraction of high angle grain boundaries with misorientation angles around 55–65° leads to a higher potential for twin formation. - Highlights: • Fraction of twinned grains and twin boundary density increase with deposition rate. • Clear increase of dislocation density was observed for the highest deposition rate. • A moderate increase of the mean grain size with increase of deposition rate is found. • For the highest deposition rate, the twin boundaries lose their coherency. • Fraction of high angle grain boundary (55–65) increases with deposition rate.

Smooth silk fibroin nanofilm deposited by 1064-nm pulsed laser beam from an opaque target

International Nuclear Information System (INIS)

Nozaki, R.; Nakayama, S.; Senna, M.

2013-01-01

In an attempt to prepare smooth nanostructured thin films of silk fibroin (SF) by near-infrared (NIR) pulsed laser deposition, an opaque target was prepared from an emulsified aqueous solution of SF. Upon irradiation of 1064-nm pulsed laser beam at its fluence 5 J/cm 2 , a thin film of SF was deposited on the Si(100) substrate with its root-mean-square surface roughness, 0.37 nm, smoother than those obtained from a compressed target of SF powders by approximately an order of magnitude. The attainment of an extra-smooth film from the opaque target was discussed in terms of multiple Mie scattering of the incident NIR beam, leading to an increase in the plasma density, intensified optical breakdown, ablation of better dispersed SF molecular units, and a film with more intensive intermolecular cross-linking. - Highlights: • Thin film of silk fibroin with its RMS surface roughness, R rms , 0.37 nm was obtained. • The use of a target from an emulsified solution of SF was the key issue. • Mechanism involved was elucidated in terms of enhanced Mie scattering

Ion beam deposition of DLC and nitrogen doped DLC thin films for enhanced haemocompatibility on PTFE

International Nuclear Information System (INIS)

Srinivasan, S.; Tang, Y.; Li, Y.S.; Yang, Q.; Hirose, A.

2012-01-01

Diamond-like carbon (DLC) and N-doped DLC (DLC:N) thin films have been synthesized on polytetrafluroethylene (PTFE) and silicon wafers using ion beam deposition. Raman spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy and scanning electron microscopy were used to study the structural and morphological properties of the coated surface. The results show that the ion beam deposited DLC thin films exhibit high hardness and Young's modulus, low coefficient of friction and high adhesion to the substrate. Low concentration of nitrogen doping in DLC improves the mechanical properties and reduces the surface roughness. DLC coating decreases the surface energy and improves the wettability of PTFE. The platelet adhesion results show that the haemocompatibility of DLC coated PTFE, especially DLC:N coated PTFE, has been significantly enhanced as compared with uncoated PTFE. SEM observations show that the platelet reaction on the DLC and DLC:N coated PTFE was minimized as the platelets were much less aggregated and activated.

Molecular beam epitaxy for the future

International Nuclear Information System (INIS)

Takahashi, K.

1984-01-01

Molecular beam epitaxy (MBE) is most commonly used to fabricate super-lattices, high electron mobility transistors, multi-quantum well lasers and other new semiconductor devices by utilizing its excellent controlability. MBE for the future is presumed to include techniques such as metalorganic chemical vapor deposition, photochemical reaction process using gas sources and ion implantation. A report on the crystal growth of GaAs using metalorganics, trimethylgallium and triethylgallium, which are usually used in chemical vapor deposition, as gaseous sources of gallium in an MBE system is made. (Author) [pt

The effect of CFRP on retrofitting of damaged HSRC beams using AE technique

Science.gov (United States)

Soffian Noor, M. S.; Noorsuhada, M. N.

2017-12-01

This paper presents the effect of carbon fibre reinforced polymer (CFRP) on retrofitted high strength reinforced concrete (HSRC) beams using acoustic emission (AE) technique. Two RC beam parameters were prepared. The first was the control beam which was undamaged HSRC beam. The second was the damaged HSRC beam retrofitted with CFRP on the soffit. The main objective of this study is to assess the crack modes of HSRC beams using AE signal strength. The relationship between signal strength, load and time were analysed and discussed. The crack pattern observed from the visual observation was also investigated. HSRC beam retrofitted with CFRP produced high signal strength compared to control beam. It demonstrates the effect of the AE signal strength for interpretation and prediction of failure modes that might occur in the beam specimens.

New technique for levitating solid particles using a proton beam

International Nuclear Information System (INIS)

Misconi, N.Y.

1996-01-01

A new technique for levitating solid particles inside a vacuum chamber is developed using a proton beam. This new technique differs from the classical laser-levitation technique invented by Ashkin in that it does not heat up light-absorbing levitated particles to vaporization. This unique property of the method will make it possible to levitate real interplanetary dust particles in a vacuum chamber and study their spin-up dynamics in a ground-based laboratory. It is found that a flux of protons from a proton gun of ∼ 10 15 cm -2 sec -1 is needed to levitate a 10-mm particle. Confinement of the levitated particle can be achieved by a Z or θ pinch to create a gravity well, or by making the beam profile doughnut in shape. In levitating real interplanetary particles, two spin-up mechanisms can be investigated using this technique: one is the Paddack Effect and the other is a spin-up mechanism by the interaction of F-coronal dust with CMEs (Coronal Mass Ejections). The real interplanetary particles were collected by Brownie and associates (also known as the Brownie Particles) from the earth's upper atmosphere. (author)

Comparative analysis of electrophysical properties of ceramic tantalum pentoxide coatings, deposited by electron beam evaporation and magnetron sputtering methods

Science.gov (United States)

Donkov, N.; Mateev, E.; Safonov, V.; Zykova, A.; Yakovin, S.; Kolesnikov, D.; Sudzhanskaya, I.; Goncharov, I.; Georgieva, V.

2014-12-01

Ta2O5 ceramic coatings have been deposited on glass substrates by e-beam evaporation and magnetron sputtering methods. For the magnetron sputtering process Ta target was used. X-ray diffraction measurements show that these coatings are amorphous. XPS survey spectra of the ceramic Ta2O5 coatings were obtained. All spectra consist of well-defined XPS lines of Ta 4f, 4d, 4p and 4s; O 1s; C 1s. Ta 4f doublets are typical for Ta2O5 coatings with two main peaks. Scanning electron microscopy and atomic force microscopy images of the e-beam evaporated and magnetron sputtered Ta2O5 ceramic coatings have revealed a relatively flat surface with no cracks. The dielectric properties of the tantalum pentoxide coatings have been investigated in the frequency range of 100 Hz to 1 MHz. The electrical behaviour of e-beam evaporated and magnetron sputtered Ta2O5 ceramic coatings have also been compared. The deposition process conditions principally effect the structure parameters and electrical properties of Ta2O5 ceramic coatings. The coatings deposited by different methods demonstrate the range of dielectric parameters due to the structural and stoichiometric composition changes

Effect of e-beam irradiation on graphene layer grown by chemical vapor deposition

International Nuclear Information System (INIS)

Iqbal, M. Z.; Kumar Singh, Arun; Iqbal, M. W.; Seo, Sunae; Eom, Jonghwa

2012-01-01

We have grown graphene by chemical vapor deposition (CVD) and transferred it onto Si/SiO 2 substrates to make tens of micron scale devices for Raman spectroscopy study. The effect of electron beam (e-beam) irradiation of various doses (600 to 12 000 μC/cm 2 ) on CVD grown graphene has been examined by using Raman spectroscopy. It is found that the radiation exposures result in the appearance of the strong disorder D band attributed the damage to the lattice. The evolution of peak frequencies, intensities, and widths of the main Raman bands of CVD graphene is analyzed as a function of defect created by e-beam irradiation. Especially, the D and G peak evolution with increasing radiation dose follows the amorphization trajectory, which suggests transformation of graphene to the nanocrystalline and then to amorphous form. We have also estimated the strain induced by e-beam irradiation in CVD graphene. These results obtained for CVD graphene are in line with previous findings reported for the mechanically exfoliated graphene [D. Teweldebrhan and A. A. Balandin, Appl. Phys. Lett. 94, 013101 (2009)]. The results have important implications for CVD graphene characterization and device fabrication, which rely on the electron microscopy.

Molecular dynamics and experimental studies on deposition mechanisms of ion beam sputtering

International Nuclear Information System (INIS)

Fang, T.-H.; Chang, W.-J.; Lin, C.-M.; Lien, W.-C.

2008-01-01

Molecular dynamics (MD) simulation and experimental methods are used to study the deposition mechanism of ionic beam sputtering (IBS), including the effects of incident energy, incident angle and deposition temperature on the growth process of nickel nanofilms. According to the simulation, the results showed that increasing the temperature of substrate decreases the surface roughness, average grain size and density. Increasing the incident angle increases the surface roughness and the average grain size of thin film, while decreasing its density. In addition, increasing the incident energy decreases the surface roughness and the average grain size of thin film, while increasing its density. For the cases of simulation, with the substrate temperature of 500 K, normal incident angle and 14.6 x 10 -17 J are appropriate, in order to obtain a smoother surface, a small grain size and a higher density of thin film. From the experimental results, the surface roughness of thin film deposited on the substrates of Si(1 0 0) and indium tin oxide (ITO) decreases with the increasing sputtering power, while the thickness of thin film shows an approximately linear increase with the increase of sputtering power

Visible light active TiO{sub 2} films prepared by electron beam deposition of noble metals

Energy Technology Data Exchange (ETDEWEB)

Hou Xinggang, E-mail: hou226@163.co [Department of Physics, Tianjin Normal University, Tianjin 300387 (China); Ma Jun [Department of Physics, Tianjin Normal University, Tianjin 300387 (China); Liu Andong [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China); Li Dejun; Huang Meidong; Deng Xiangyun [Department of Physics, Tianjin Normal University, Tianjin 300387 (China)

2010-03-15

TiO{sub 2} films prepared by sol-gel method were modified by electron beam deposition of noble metals (Pt, Pd, and Ag). Effects of noble metals on the chemical and surface characteristics of the films were studied using XPS, TEM and UV-Vis spectroscopy techniques. Photocatalytic activity of modified TiO{sub 2} films was evaluated by studying the degradation of methyl orange dye solution under visible light UV irradiation. The result of TEM reveals that most of the surface area of TiO{sub 2} is covered by tiny particles of noble metals with diameter less than 1 nm. Broad red shift of UV-Visible absorption band of modified photocatalysts was observed. The catalytic degradation of methyl orange in aqueous solutions under visible light illumination demonstrates a significant enhancement of photocatalytic activity of these films compared with the un-loaded films. The photocatalytic efficiency of modified TiO{sub 2} films by this method is affected by the concentration of impregnating solution.

MODELLING THE DELAMINATION FAILURE ALONG THE CFRP-CFST BEAM INTERACTION SURFACE USING DIFFERENT FINITE ELEMENT TECHNIQUES

Directory of Open Access Journals (Sweden)

AHMED W. AL-ZAND

2017-01-01

Full Text Available Nonlinear finite element (FE models are prepared to investigate the behaviour of concrete-filled steel tube (CFST beams strengthened by carbon fibre reinforced polymer (CFRP sheets. The beams are strengthened from the bottom side only by varied sheet lengths (full and partial beam lengths and then subjected to ultimate flexural loads. Three surface interaction techniques are used to implement the bonding behaviour between the steel tube and the CFRP sheet, namely, full tie interaction (TI, cohesive element (CE and cohesive behaviour (CB techniques using ABAQUS software. Results of the comparison between the FE analysis and existing experimental study confirm that the FE models with the TI technique could be applicable for beams strengthened by CFRP sheets with a full wrapping length; the technique could not accurately implement the CFRP delamination failure, which occurred for beams with a partial wrapping length. Meanwhile, the FE models with the CE and CB techniques are applicable in the implementation of both CFRP failures (rapture and delamination for both full and partial wrapping lengths, respectively. Where, the ultimate loads' ratios achieved by the FE models using TI, CE and CB techniques about 1.122, 1.047 and 1.045, respectively, comparing to the results of existing experimental tests.

Ion beam analysis techniques applied to large scale pollution studies

Energy Technology Data Exchange (ETDEWEB)

Cohen, D D; Bailey, G; Martin, J; Garton, D; Noorman, H; Stelcer, E; Johnson, P [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1994-12-31

Ion Beam Analysis (IBA) techniques are ideally suited to analyse the thousands of filter papers a year that may originate from a large scale aerosol sampling network. They are fast multi-elemental and, for the most part, non-destructive so other analytical methods such as neutron activation and ion chromatography can be performed afterwards. ANSTO in collaboration with the NSW EPA, Pacific Power and the Universities of NSW and Macquarie has established a large area fine aerosol sampling network covering nearly 80,000 square kilometres of NSW with 25 fine particle samplers. This network known as ASP was funded by the Energy Research and Development Corporation (ERDC) and commenced sampling on 1 July 1991. The cyclone sampler at each site has a 2.5 {mu}m particle diameter cut off and runs for 24 hours every Sunday and Wednesday using one Gillman 25mm diameter stretched Teflon filter for each day. These filters are ideal targets for ion beam analysis work. Currently ANSTO receives 300 filters per month from this network for analysis using its accelerator based ion beam techniques on the 3 MV Van de Graaff accelerator. One week a month of accelerator time is dedicated to this analysis. Four simultaneous accelerator based IBA techniques are used at ANSTO, to analyse for the following 24 elements: H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Co, Zn, Br and Pb. The IBA techniques were proved invaluable in identifying sources of fine particles and their spatial and seasonal variations accross the large area sampled by the ASP network. 3 figs.

Ion beam analysis techniques applied to large scale pollution studies

Energy Technology Data Exchange (ETDEWEB)

Cohen, D.D.; Bailey, G.; Martin, J.; Garton, D.; Noorman, H.; Stelcer, E.; Johnson, P. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1993-12-31

Ion Beam Analysis (IBA) techniques are ideally suited to analyse the thousands of filter papers a year that may originate from a large scale aerosol sampling network. They are fast multi-elemental and, for the most part, non-destructive so other analytical methods such as neutron activation and ion chromatography can be performed afterwards. ANSTO in collaboration with the NSW EPA, Pacific Power and the Universities of NSW and Macquarie has established a large area fine aerosol sampling network covering nearly 80,000 square kilometres of NSW with 25 fine particle samplers. This network known as ASP was funded by the Energy Research and Development Corporation (ERDC) and commenced sampling on 1 July 1991. The cyclone sampler at each site has a 2.5 {mu}m particle diameter cut off and runs for 24 hours every Sunday and Wednesday using one Gillman 25mm diameter stretched Teflon filter for each day. These filters are ideal targets for ion beam analysis work. Currently ANSTO receives 300 filters per month from this network for analysis using its accelerator based ion beam techniques on the 3 MV Van de Graaff accelerator. One week a month of accelerator time is dedicated to this analysis. Four simultaneous accelerator based IBA techniques are used at ANSTO, to analyse for the following 24 elements: H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Co, Zn, Br and Pb. The IBA techniques were proved invaluable in identifying sources of fine particles and their spatial and seasonal variations accross the large area sampled by the ASP network. 3 figs.

Influence of ion beam and geometrical parameters on properties of Si thin films grown by Ar ion beam sputtering

Energy Technology Data Exchange (ETDEWEB)

Bundesmann, Carsten; Feder, Rene; Neumann, Horst [Leibniz-Institut fuer Oberflaechenmodifizierung e.V., Leipzig (Germany)

2012-07-01

Ion beam sputtering (IBS) offers, in contrast to other physical vapour deposition techniques, such as magnetron sputtering or electron beam evaporation, the opportunity to change the properties of the layer forming particles (sputtered and scattered particles) by varying ion beam parameters (ion species, ion energy) and geometrical parameters (ion incidence angle, emission angle). Consequently, these effects can be utilized to tailor thin film properties [1]. The goal is to study systematically the correlations between the primary and secondary parameters and, at last, the effects on the properties of Si thin films, such as optical properties, stress, surface topography and composition. First experimental results are presented for Ar-ion sputtering of Si.

Proceedings of the national symposium on vacuum science and technology and power beams. Volume 2

International Nuclear Information System (INIS)

Venkatramani, N.; Ray, A.K.

1997-11-01

This volume contains the proceedings of the national symposium on vacuum science and technology and power beams. The main topics dealt with are: accelerators and vacuum systems, thin films deposition techniques, lasers and electron power beams and their applications in nuclear facilities. Papers relevant to INIS are indexed separately

Closed-Loop Process Control for Electron Beam Freeform Fabrication and Deposition Processes

Science.gov (United States)

Taminger, Karen M. (Inventor); Hafley, Robert A. (Inventor); Martin, Richard E. (Inventor); Hofmeister, William H. (Inventor)

2013-01-01

A closed-loop control method for an electron beam freeform fabrication (EBF(sup 3)) process includes detecting a feature of interest during the process using a sensor(s), continuously evaluating the feature of interest to determine, in real time, a change occurring therein, and automatically modifying control parameters to control the EBF(sup 3) process. An apparatus provides closed-loop control method of the process, and includes an electron gun for generating an electron beam, a wire feeder for feeding a wire toward a substrate, wherein the wire is melted and progressively deposited in layers onto the substrate, a sensor(s), and a host machine. The sensor(s) measure the feature of interest during the process, and the host machine continuously evaluates the feature of interest to determine, in real time, a change occurring therein. The host machine automatically modifies control parameters to the EBF(sup 3) apparatus to control the EBF(sup 3) process in a closed-loop manner.

A new technique for ion beam tritium labelling

International Nuclear Information System (INIS)

Zhang Nianbao; Sheng Shugang; Yao Fuzeng

1990-06-01

An advanced technique, the ion beam tritium labelling method (IBTL), used for labelling proteins, peptides and other nonvolatile organic compounds is introduced. In this method the excited tritium ion beam is accelerated and then bombs a solid sample target in which tritium exchanging for hydrogen is taken place. The IBTL has been used for preparation of tritiated soybean trypsin inhibitor, ribonuclease A, elastin and pachyman etc. After purifing by dialysis, ion exchange chromatography and gel filtration, the tritiated proteins and polysaccharide were obtained with the specific activity over 37 GBq/mmol, the function of tritiated decomposition products was not found. The product was shown to have native biological activity. Amino acid analysis of tritiated protein showed that the relative specific radioactivities were higher for His., Tyr. and Phe. but lower for Val., Ile. and Ser

Dynamic energy spectrum and energy deposition in solid target by intense pulsed ion beams

Institute of Scientific and Technical Information of China (English)

Xiao Yu; Xiao-Yun Le; Zheng Liu; Jie Shen; Yu I.Isakova; Hao-Wen Zhong; Jie Zhang; Sha Yan; Gao-Long Zhang; Xiao-Fu Zhang

2017-01-01

A method for analyzing the dynamic energy spectrum of intense pulsed ion beam (IPIB) was proposed.Its influence on beam energy deposition in metal target was studied with IPIB produced by two types of magnetically insulated diodes (MID).The emission of IPIB was described with space charge limitation model,and the dynamic energy spectrum was further analyzed with time-of-flight method.IPIBs generated by pulsed accelerators of BIPPAB-450 (active MID) and TEMP-4M (passive MID) were studied.The dynamic energy spectrum was used to deduce the power density distribution of IPIB in the target with Monte Carlo simulation and infrared imaging diagnostics.The effect on the distribution and evolution of thermal field induced by the characteristics of IPIB dynamic energy spectrum was discussed.

Investigation of industrial-scale carbon dioxide reduction using pulsed electron beams

Energy Technology Data Exchange (ETDEWEB)

Petrov, G. M.; Apruzese, J. P.; Petrova, Tz. B.; Wolford, M. F. [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375-5346 (United States)

2016-03-14

Carbon dioxide is the most important greenhouse gas contributing to global warming. To help mitigate increasing CO{sub 2} concentrations, we investigate a method of carbon dioxide reduction using high-power electron beams, which can be used on an industrial scale. A series of experiments are conducted in which the reduction of CO{sub 2} is measured for different gas compositions and power deposition rates. An electron beam deposition model is applied to compute reduction rates of CO{sub 2} and energy cost for breaking a CO{sub 2} molecule in flue gas and pure carbon dioxide at atmospheric pressure. For flue gas consisting of 82% N{sub 2}, 6% O{sub 2}, and 12% CO{sub 2}, the calculated energy cost is 85 eV per molecule. In order to dissociate 50% of the CO{sub 2} molecules, beam energy density deposition on the order of 20 J/cm{sup 3} is required. Electron beam irradiation of 12.6 liter gas volume containing 90% CO{sub 2} and 10% CH{sub 4} at beam energy density deposition of 4.2 J/cm{sup 3}, accumulated over 43 shots in a 20 min interval, reduced the CO{sub 2} concentration to 78%. Analogous experiments with a gas mixture containing 11.5% CO{sub 2}, 11.5% CH{sub 4}, and balance of Ar, reduced the CO{sub 2} concentration to below 11% with energy deposition 0.71 J/cm{sup 3}, accumulated over 10 shots in a 5 min interval. The experimental data and the theoretical predictions of CO{sub 2} reduction using pulsed electron beams are in agreement within the experimental error. Other techniques to enhance the removal of CO{sub 2} with pulsed electron beams are also explored, yielding new possible avenues of research.

Importance of dewetting in organic molecular-beam deposition: Pentacene on gold

International Nuclear Information System (INIS)

Beernink, G.; Strunskus, T.; Witte, G.; Woell, Ch.

2004-01-01

Organic molecular-beam deposition of pentacene on gold substrates has been investigated using a multitechnique approach. The morphology of the organic thin films depends strongly on the substrate temperature. Pronounced dewetting and island formation are observed at room temperature. Whereas pentacene molecules adopt a planar monolayer structure, they continue to grow in an upright orientation in multilayer films as inferred from x-ray absorption spectroscopy and atomic force microscopy. These results are in pronounced contrast to a recent scanning tunneling microscopy (STM) study by Kang and Zhu [Appl. Phys. Lett. 82, 3248 (2003)] and indicate fundamental problems in the interpretation of STM measurements for organic thin films

Carbon nitride films synthesized by NH3-ion-beam-assisted deposition

International Nuclear Information System (INIS)

Song, H.W.; Cui, F.Z.; He, X.M.; Li, W.Z.; Li, H.D.

1994-01-01

Carbon nitride thin film films have been prepared by NH 3 -ion-beam-assisted deposition with bombardment energies of 200-800 eV at room temperature. These films have been characterized by transmission electron microscopy. Auger electron spectroscopy and x-ray photoelectron spectroscopy for chemical analysis. It was found that the structure of the films varied with the bombardment energy. In the case of 400 eV bombardment, the tiny crystallites immersed on an amorphous matrix were identified to be β-C 3 N 4 . X-ray photoelectron spectroscopy indicated that some carbon atoms and nitrogen atoms form unpolarized covalent bonds in these films. (Author)

Source reconstruction using phase space beam summation technique

International Nuclear Information System (INIS)

Graubart, Gideon.

1990-10-01

In this work, the phase-space beam summation technique (PSBS), is applied to back propagation and inverse source problems. The PSBS expresses the field as a superposition of shifted and tilted beams. This phase space spectrum of beams is matched to the source distribution via an amplitude function which expresses the local spectrum of the source function in terms of a local Fourier transform. In this work, the emphasis is on the phase space processing of the data, on the information content of this data and on the back propagation scheme. More work is still required to combine this back propagation approach in a full, multi experiment inverse scattering scheme. It is shown that the phase space distribution of the data, computed via the local spectrum transform, is localized along lines that define the local arrival direction of the wave data. We explore how the choice of the beam width affects the compactification of this distribution, and derive criteria for choosing a window that optimizes this distribution. It should be emphasized that compact distribution implies fewer beams in the back propagation scheme and therefore higher numerical efficiency and better physical insight. Furthermore it is shown how the local information property of the phase space representation can be used to improve the performance of this simple back propagation problem, in particular with regard to axial resolution; the distance to the source can be determined by back propagating only the large angle phase space beams that focus on the source. The information concerning transverse distribution of the source, on the other hand, is contained in the axial phase space region and can therefore be determined by the corresponding back propagating beams. Because of the global nature of the plane waves propagators the conventional plane wave back propagation scheme does not have the same 'focusing' property, and therefore suffers from lack of information localization and axial resolution. The

Suspended tungsten-based nanowires with enhanced mechanical properties grown by focused ion beam induced deposition

Science.gov (United States)

Córdoba, Rosa; Lorenzoni, Matteo; Pablo-Navarro, Javier; Magén, César; Pérez-Murano, Francesc; María De Teresa, José

2017-11-01

The implementation of three-dimensional (3D) nano-objects as building blocks for the next generation of electro-mechanical, memory and sensing nano-devices is at the forefront of technology. The direct writing of functional 3D nanostructures is made feasible by using a method based on focused ion beam induced deposition (FIBID). We use this technique to grow horizontally suspended tungsten nanowires and then study their nano-mechanical properties by three-point bending method with atomic force microscopy. These measurements reveal that these nanowires exhibit a yield strength up to 12 times higher than that of the bulk tungsten, and near the theoretical value of 0.1 times the Young’s modulus (E). We find a size dependence of E that is adequately described by a core-shell model, which has been confirmed by transmission electron microscopy and compositional analysis at the nanoscale. Additionally, we show that experimental resonance frequencies of suspended nanowires (in the MHz range) are in good agreement with theoretical values. These extraordinary mechanical properties are key to designing electro-mechanically robust nanodevices based on FIBID tungsten nanowires.

Radioactive ion beams produced by neutron-induced fission at ISOLDE

CERN Document Server

Catherall, R; Gilardoni, S S; Köster, U

2003-01-01

The production rates of neutron-rich fission products for the next-generation radioactive beam facility EURISOL are mainly limited by the maximum amount of power deposited by protons in the target. An alternative approach is to use neutron beams to induce fission in actinide targets. This has the advantage of reducing: the energy deposited by the proton beam in the target; contamination from neutron-deficient isobars that would be produced by spallation; and mechanical stress on the target. At ISOLDE CERN, tests have been made on standard ISOLDE actinide targets using fast neutron bunches produced by bombarding thick, high-Z metal converters with 1 and 1.4 GeV proton pulses. This paper reviews the first applications of converters used at ISOLDE. It highlights the different geometries and the techniques used to compare fission yields produced by the proton beam directly on the target with neutron-induced fission. Results from the six targets already tested, namely UC2/graphite and ThO2 targets with tungsten an...

Growth of CdTe on Si(100) surface by ionized cluster beam technique: Experimental and molecular dynamics simulation

Energy Technology Data Exchange (ETDEWEB)

Araghi, Houshang, E-mail: araghi@aut.ac.ir [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Zabihi, Zabiholah [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Nayebi, Payman [Department of Physics, College of Technical and Engineering, Saveh Branch, Islamic Azad University, Saveh (Iran, Islamic Republic of); Ehsani, Mohammad Mahdi [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

2016-10-15

II–VI semiconductor CdTe was grown on the Si(100) substrate surface by the ionized cluster beam (ICB) technique. In the ICB method, when vapors of solid materials such as CdTe were ejected through a nozzle of a heated crucible into a vacuum region, nanoclusters were created by an adiabatic expansion phenomenon. The clusters thus obtained were partially ionized by electron bombardment and then accelerated onto the silicon substrate at 473 K by high potentials. The cluster size was determined using a retarding field energy analyzer. The results of X-ray diffraction measurements indicate the cubic zinc blende (ZB) crystalline structure of the CdTe thin film on the silicon substrate. The CdTe thin film prepared by the ICB method had high crystalline quality. The microscopic processes involved in the ICB deposition technique, such as impact and coalescence processes, have been studied in detail by molecular dynamics (MD) simulation.

3D assembly of carbon nanotubes for fabrication of field-effect transistors through nanomanipulation and electron-beam-induced deposition

International Nuclear Information System (INIS)

Yu, Ning; Shi, Qing; Wang, Huaping; Huang, Qiang; Fukuda, Toshio; Nakajima, Masahiro; Yang, Zhan; Sun, Lining

2017-01-01

Three-dimensional carbon nanotube field-effect transistors (3D CNTFETs) possess predictable characteristics that rival those of planar CNTFETs and Si-based MOSFETs. However, due to the lack of a reliable assembly technology, they are rarely reported on, despite the amount of attention they receive. To address this problem, we propose the novel concept of a 3D CNTFET and develop its assembly strategy based on nanomanipulation and the electron-beam-induced deposition (EBID) technique inside a scanning electron microscope (SEM). In particular, the electrodes in our transistor design are three metallic cuboids of the same size, and their front, top and back surfaces are all wrapped up in CNTs. The assembly strategy is employed to build the structure through a repeated basic process of pick-up, placement, fixing and cutting of CNTs. The pick-up and placement is performed through one nanomanipulator with four degrees of freedom. Fixing is carried out through the EBID technique so as to improve the mechanical and electrical characteristics of the CNT/electrodes connection. CNT cutting is undertaken using the typical method of electrical breakdown. Experimental results showed that two CNTs were successfully assembled on the front sides of the cubic electrodes. This validates our assembly method for the 3D CNTFET. Also, when contact resistance was measured, tens of kilohms of resistance was observed at the CNT-EBID deposition-FET electrodes junction.. This manifests the electrical reliability of our assembly strategy. (paper)

Surface Resistance Measurements and Estimate of the Beam-Induced Resistive Wall Heating of the LHC Dipole Beam Screen

CERN Document Server

Caspers, Friedhelm; Ruggiero, F; Tan, J

1999-01-01

An estimate of the resistive losses in the LHC beam screen is given from cold surface resistance measurements using the shielded pair technique, with particular emphasis on the effect of a high magnetic field. Two different copper coating methods, namely electro-deposition and co-lamination, have been evaluated. Experimental data are compared with theories including the anomalous skin effect and the magneto-resistance effect. It is shown whether the theory underestimates or not the losses depends strongly on the RRR value, on the magnetic field and on the surface characteristics. In the pessimistic case and for nominal machine parameters, the estimated beam-induced resistive wall heating can be as large as 260 mW/m for two circulating beams.

Electrical characterization of defects introduced in n-Si during electron beam deposition of Pt

Energy Technology Data Exchange (ETDEWEB)

Auret, F.D.; Coelho, S.M.M.; Nel, J.M.; Meyer, W.E. [Physics Department, University of Pretoria, Pretoria (South Africa)

2012-10-15

We have used deep level transient spectroscopy (DLTS) and high resolution DLTS to characterize the defects introduced in epitaxially grown n-type, P-doped, Si during electron beam deposition (EBD) of Pt for Schottky contact formation. The identity of some of these defects could be established by comparing their properties to those of well-known defects introduced by high energy electron irradiation of the same material. The most prominent EBD-induced defects thus identified were the E-center (VP center), the A-center (VO center), interstitial carbon (C{sub i}), and the interstitial carbon-substitutional carbon (C{sub i}C{sub s}) pair. EBD also introduced some defects that were not observed after high energy electron irradiation. DLTS depth profiling revealed that the main defects, VO and VP, could be detected up to 0.5 {mu}m below the metal-Si interface. Shielding the sample from particles originating in the region of the electron beam significantly reduced defect introduction and resulted in Schottky contacts with improved rectification properties. Finally, we have found that exposing the sample to EBD conditions, without actually depositing metal, introduced a different set of electron traps, not introduced by the EBD process. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Auger electron spectroscopy analysis of high metal content micro-structures grown by electron beam induced deposition

International Nuclear Information System (INIS)

Cicoira, F.; Hoffmann, P.; Olsson, C.O.A.; Xanthopoulos, N.; Mathieu, H.J.; Doppelt, P.

2005-01-01

An auger electron spectroscopy study was carried out on Rh-containing micro-structures grown by electron beam induced deposition (EBID) of the iso-structural and iso-electronic precursors [RhCl(PF 3 ) 2 ] 2 and [RhCl(CO) 2 ] 2 . A material containing between 55 and 60 at.% Rh was obtained from both precursors. The chemical composition of structures grown from the two different precursors indicates a similar decomposition mechanism. Deposits grown from [RhCl(PF 3 ) 2 ] 2 showed a chemical composition independent of electron energy and electron dose in the investigated range of conditions

A calculation technique of passing of a powerful relativistic beam through substance

International Nuclear Information System (INIS)

Pobitko, A.I.; Sal'nikov, L.I.; Sukhovitskij, E.Sh.

1995-01-01

The calculation algorithm of passing powerful relativistic beam through substance is developed. Algorithm of calculation is separated on the following problems: 1) a trial charge movement in electromagnetic field of the cylindrical geometry; 2) a computing of own electromagnetic field arising at movement of a particle heavy-current beam in a target; 3) accounting of an interaction of a beam with target atoms; 4) accounting of change of the target properties in a time; 5) geometry and construction of an iterative procedure of calculation. The calculation of passing heavy-current beams of charged particles for transient case is carried out by Monte Carlo method. A conclusion of equations of movement trial charge and technique of calculation own electromagnetic field of the powerful relativistic beam at passing through substance are resulted. 6 refs

New technique of skin embedded wire double-sided laser beam welding

Science.gov (United States)

Han, Bing; Tao, Wang; Chen, Yanbin

2017-06-01

In the aircraft industry, double-sided laser beam welding is an approved method for producing skin-stringer T-joints on aircraft fuselage panels. As for the welding of new generation aluminum-lithium alloys, however, this technique is limited because of high hot cracking susceptibility and strengthening elements' uneven distributions within weld. In the present study, a new technique of skin embedded wire double-sided laser beam welding (LBW) has been developed to fabricate T-joints consisting of 2.0 mm thick 2060-T8/2099-T83 aluminum-lithium alloys using eutectic alloy AA4047 filler wire. Necessary dimension parameters of the novel groove were reasonably designed for achieving crack-free welds. Comparisons were made between the new technique welded T-joint and conventional T-joint mainly on microstructure, hot crack, elements distribution features and mechanical properties within weld. Excellent crack-free microstructure, uniform distribution of silicon and superior tensile properties within weld were found in the new skin embedded wire double-sided LBW T-joints.

Energy deposition profile for modification proposal of ISOLDE’s HRS Beam Dump, from FLUKA simulations

CERN Document Server

Vlachoudis, V

2014-01-01

The current ISOLDE HRS beam dump has been found to be unsuitable on previous simulations, due to thermomechanical stresses. In this paper a proposal for modifying HRS dump is studied using FLUKA. The energy deposited in this modified beam dump and the amount of neutrons streaming to the tunnel area are scored and compared with the simulation of current dump. Two versions of the modification have been assessed, determining which of them is more desirable in terms of influence of radiation on ISOLDE’s tunnel. Finally, a rough estimate of temperature raise in the modified dump is shown. Further conclusions on the adequacy of these modifications need to include the thermomechanical calculations’ results, based on those presented here.

RF photo-injector beam energy distribution studies by slicing technique

Science.gov (United States)

Filippetto, D.; Bellaveglia, M.; Musumeci, P.; Ronsivalle, C.

2009-07-01

The SPARC photo-injector is an R&D facility dedicated to the production of high brightness electron beams for radiation generation via FEL or Thomson scattering processes. It is the prototype injector for the recently approved SPARX project, aiming at the construction in the Frascati/University of Rome Tor Vergata area of a new high brightness electron linac for the generation of SASE-FEL radiation in the 1-10 nm wavelength range. The first phase of the SPARC project has been dedicated to the e-beam source characterization; the beam transverse and longitudinal parameters at the exit of the gun have been measured, and the photo-injector settings optimized to achieve best performance. Several beam dynamics topics have been experimentally studied in this first phase of operation, as, for example, the effect of photocathode driver laser beam shaping and the evolution of the beam transverse emittance. These studies have been made possible by the use of a novel diagnostic tool, the " emittance-meter" which enables the measurement of the transverse beam parameters at different positions along the propagation axis in the very interesting region at the exit of the RF gun. The new idea of extending the e-meter capabilities came out more recently. Information on the beam longitudinal phase space and correlations with the transverse planes can be retrieved by the slicing technique. In this paper, we illustrate the basic concept of the measurement together with simulations that theoretically validate the methodology. Some preliminary results are discussed and explained with the aid of code simulations.

Power deposition by neutral beam injected fast ions in field-reversed configurations

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasaka, Naotaka

2004-04-01

Effects of Coulomb collisions on neutral beam (NB) injected fast ions into Field-Reversed Configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing down and pitch angle collisions. The Monte-Carlo method is used for the pitch angle scattering, and the friction term is added to the equation of motion to show effects of slowing down collision such as the deposited power profile. Calculation parameters used are relevant to the NB injection on the FRC Injection Experiment (FIX) device. It is found that the dominant local power deposition occurs in the open field region between the X-point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found negligible. The loss mechanism due to non-adiabatic fast ion motion, which is intrinsic in non-uniform FRC plasmas, affects much greater than the pitch angle scattering by Coulomb collision. (author)

Effect of ion beam bombardment on the carbide in M2 steel modified by ion-beam-assisted deposition

Energy Technology Data Exchange (ETDEWEB)

Li, X.Y.; Wang, F.J.; Wang, Y.K. (Dept. of Materials Engineering, Dalian Univ. of Technology (China)); Ma, T.C. (National Lab. of Materials Modification by Beam Three, Dalian (China))

1991-10-30

Transmission electron microscopy was used to study the effect of nitrogen ion bombardment with different doses on the carbides in M2 high speed steel as the nitrogen ions penetrated into the nitride films during ion-beam-assisted deposition. With different doses of nitrogen, alterations in the morphological characteristics of the carbide M6C at the interface were observed. With lower doses, knitting-like contrast within the carbide showed subboundary structure defects in M6C. With increasing dose, the substructure defects were broken up into small fragments owing to heavy bombardment. The microstructures of carbides at the interface damaged by nitrogen ions are discussed in detail. (orig.).

The deposition of thin metal films at the high-intensity pulsed-ion-beam influence on the metals

International Nuclear Information System (INIS)

Remnev, G.E.; Zakoutaev, A.N.; Grushin, I.I.; Matvenko, V.M.; Potemkin, A.V.; Ryzhkov, V.A.; Chernikov, E.V.

1996-01-01

A high-intensity pulsed ion beam with parameters: ion energy 350-500 keV, ion current density at a target > 200 A/cm 2 , pulse duration 60 ns, was used for metal deposition. The film deposition rate was 0.6-4.0 mm/s. Transmission electron microscopy/transmission electron diffraction investigations of the copper target-film system were performed. The impurity content in the film was determined by x-ray fluorescence analysis and secondary ion mass spectrometry. The angular distributions of the ablated plasma were measured. (author). 2 figs., 7 refs

The deposition of thin metal films at the high-intensity pulsed-ion-beam influence on the metals

Energy Technology Data Exchange (ETDEWEB)

Remnev, G E; Zakoutaev, A N; Grushin, I I; Matvenko, V M; Potemkin, A V; Ryzhkov, V A [Tomsk Polytechnic Univ. (Russian Federation). Nuclear Physics Inst.; Ivanov, Yu F [Construction Academy, Tomsk (Russian Federation); Chernikov, E V [Siberian Physical Technical Institute, Tomsk (Russian Federation)

1997-12-31

A high-intensity pulsed ion beam with parameters: ion energy 350-500 keV, ion current density at a target > 200 A/cm{sup 2}, pulse duration 60 ns, was used for metal deposition. The film deposition rate was 0.6-4.0 mm/s. Transmission electron microscopy/transmission electron diffraction investigations of the copper target-film system were performed. The impurity content in the film was determined by x-ray fluorescence analysis and secondary ion mass spectrometry. The angular distributions of the ablated plasma were measured. (author). 2 figs., 7 refs.

Phase aberrations and beam cleanup techniques in carbon-dioxide laser fusion systems

International Nuclear Information System (INIS)

Viswanathan, V.K.

1981-01-01

This paper describes the various carbon dioxide laser fusion systems at Los Alamos from the point of view of an optical designer. The types of phase aberrations present in these systems, as well as the beam cleanup techniques that can be used to improve the beam optical quality, are discussed. As this is a review article, some previously published results are also used where relevant

Beam profile measurements on the advanced test accelerator using optical techniques

International Nuclear Information System (INIS)

Chong, Y.P.; Kalibjian, R.; Cornish, J.P.; Kallman, J.S.; Donnelly, D.

1986-01-01

Beam current density profiles of ATA have been measured both spatially and temporally using a number of diagnostics. An extremely important technique involves measuring optical emissions from either a target foil inserted into the beam path or gas atoms and molecules excited by beam electrons. This paper describes the detection of the optical emission. A 2-D gated television camera with a single or dual micro-channel-plate (MCP) detector for high gain provides excellent spatial and temporal resolution. Measurements are routinely made with resolutions of 1 mm and 5 ns respectively. The optical line of sight allows splitting part of the signal to a streak camera or photometer for even higher time resolution

Dosimetric evaluations and comparisons between different techniques (Fan beam, Cone beam, OPT) in the dental industry and not

International Nuclear Information System (INIS)

Rampado, O.

2014-01-01

In recent years there has been an impressive evolution and spread of cone beam tomographic equipment, in particular in the dental and maxillofacial surgery. These devices exhibit unique characteristics both from the point of view of the geometric parameters of exposure than the quality of the beams radiating employed. In parallel to this technological development it was dealt with the quantification of the dose to the patient, with a discussion between experts to define what are the variables most appropriate to use and the appropriate ways of measuring. And it is of interest also the discussion on the comparison of the risks associated with the use of this method as an alternative to traditional techniques or other tomographic techniques, both on the criteria of optimization in the realization of the tests.

Thermoelectric Properties of Nanograined Si-Ge-Au Thin Films Grown by Molecular Beam Deposition

Science.gov (United States)

Nishino, Shunsuke; Ekino, Satoshi; Inukai, Manabu; Omprakash, Muthusamy; Adachi, Masahiro; Kiyama, Makoto; Yamamoto, Yoshiyuki; Takeuchi, Tsunehiro

2018-06-01

Conditions to achieve extremely large Seebeck coefficient and extremely small thermal conductivity in Si-Ge-Au thin films formed of nanosized grains precipitated in amorphous matrix have been investigated. We employed molecular beam deposition to prepare Si1- x Ge x Au y thin films on sapphire substrate. The deposited films were annealed under nitrogen gas atmosphere at 300°C to 500°C for 15 min to 30 min. Nanocrystals dispersed in amorphous matrix were clearly observed by transmission electron microscopy. We did not observe anomalously large Seebeck coefficient, but very low thermal conductivity of nearly 1.0 W K-1 m-1 was found at around 0.2 Si-Ge bulk material for which dimensionless figure of merit of ZT ≈ 1 was reported at high temperature.

Optical and Electrical Properties of Tin-Doped Cadmium Oxide Films Prepared by Electron Beam Technique

Science.gov (United States)

Ali, H. M.; Mohamed, H. A.; Wakkad, M. M.; Hasaneen, M. F.

2009-04-01

Tin-doped cadmium oxide films were deposited by electron beam evaporation technique. The structural, optical and electrical properties of the films were characterized. The X-ray diffraction (XRD) study reveals that the films are polycrystalline in nature. As composition and structure change due to the dopant ratio and annealing temperature, the carrier concentration was varied around 1020 cm-3, and the mobility increased from less than 10 to 45 cm2 V-1 s-1. A transmittance value of ˜83% and a resistivity value of 4.4 ×10-4 Ω cm were achieved for (CdO)0.88(SnO2)0.12 film annealed at 350 °C for 15 min., whereas the maximum value of transmittance ˜93% and a resistivity value of 2.4 ×10-3 Ω cm were obtained at 350 °C for 30 min. The films exhibited direct band-to-band transitions, which corresponded to optical band gaps of 3.1-3.3 eV.

Hydrodynamic calculations of 20-TeV beam interactions with the SSC beam dump

International Nuclear Information System (INIS)

Wilson, D.C.; Wingate, C.A.; Goldstein, J.C.; Godwin, R.P.; Mokhov, N.V.

1993-01-01

The 300μs, 400 MJ SSC proton beam must be contained when extracted to the external beam dump. The current design for the SSC beam dump can tolerate the beat load produced if the beam is deflected into a raster scan over the face of the dump. If the high frequency deflecting magnet were to fail, the beam would scan a single strip across the dump face resulting in higher local energy deposition. This could vaporize some material and lead to high pressures. Since the beam duration is comparable to the characteristic time of expected hydrodynamic motions, we have combined the static energy deposition capability of the MARS computer code with the two- and three-dimensional hydrodynamics of the MBA and SPHINX codes. EOS data suggest an energy deposition threshold of 15 kJ/g, below which hydrodynamic effects are minimal. Above this our 2D calculations show a hole boring rate of 7 cm/μs for the nominal beam, and pressures of a few kbar. Scanning the nominal beam faster than 0.08 cm/μs should minimize hydrodynamic effects. 3D calculations support this

Moving strip technique of electron beam therapy

Energy Technology Data Exchange (ETDEWEB)

Matsushima, Kishio; Wakasa, Hiroyuki; Oguri, Nobuhiro; Kitayama, Takuichi; Nakagiri, Yoshitada; Mikami, Yasutaka; Hashimoto, Keiji; Hiraki, Yoshio; Aono, Kaname

1984-12-01

The fieldsize in electron beam therapy is determined by the cone size. In case of skin metastasis of a malignant tumor and so on, which need a large field size and whose area is much larger than the size of the cone, a large field size is usually produced by dividing the portals. However, the dose distribution at the border of the field becomes unequal, and hot and cold dose areas are produced according to the distance between portals. We tried the strip field technique in a large field along the long axis of the body in order to flatten the dose of the border employing the moving strip used for whole abdominal irradiation in ovarian cancer. We set the film in Mix-DP and used the strip field technique with 2.5cm steps. We discussed the relationship between the interval (distance between portals) and the flattening of the dose within the field. Skin movement due to breathing and influences on the flattening of the dose were considered. The proper flatness was obtained at depths of 0,1,2, and 3cm by setting the interval at 0.5cm. When skin movement was produced by breathing in +-1.5mm, the proper flaness was obtained also at a 0.5-cm interval. It seems that smoothing is increased by breathing. An ''electron beam moving strip'' with a 2.5-cm step and 0.5-cm interval was clinically effective in the treatment of patients with skin metastasis of colon cancer. (author).

Production of BiPbSrCaCuO thin films on MgO and Ag/MgO substrates by electron beam deposition techniques

CERN Document Server

Varilci, A; Gorur, O; Celebi, S; Karaca, I

2002-01-01

Superconducting BiPbSrCaCuO thin films were prepared on MgO(001) and Ag/MgO substrates using an electron beam (e-beam) evaporation technique. The effects of annealing temperature and Ag diffusion on the crystalline structure and some superconducting properties, respectively, were investigated by X-ray diffraction, atomic force microscopy, and by measurements of the critical temperature and the critical current density. It was shown that an annealing of both types of films at 845 or 860 C resulted in the formation of mixed Bi-2223 and Bi-2212 phases with a high degree of preferential orientation with the c-axis perpendicular to the substrates. The slight increase of the critical temperature from 103 K to 105 K, the enhancement of the critical current density from 2 x 10 sup 3 to 6 x 10 sup 4 A/cm sup 2 , and the improved surface smoothness are due to a possible silver doping from the substrate. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

X-ray-ultraviolet beam splitters for the Michelson interferometer

International Nuclear Information System (INIS)

Delmotte, Franck; Ravet, Marie-Francoise; Bridou, Francoise; Varniere, Francoise; Zeitoun, Philippe; Hubert, Sebastien; Vanbostal, Laurent; Soullie, Gerard

2002-01-01

With the aim of realizing a Michelson interferometer working at 13.9 nm, we have developed a symmetrical beam splitter with multilayers deposited on the front and back sides of a silicon nitride membrane. On the basis of the experimental optical properties of the membrane, simulations have been performed to define the multilayer structure that provides the highest reflectivity-transmission product. Optimized Mo-Si multilayers have been successfully deposited on both sides of the membrane by use of the ion-beam sputtering technique, with a thickness-period reproducibility of 0.1 nm. Measurements by means of synchrotron radiation at 13.9 nm and at an angle of 45 deg. provide a reflectivity of 14.2% and a transmission of 15.2% for a 60% s-polarized light, close to the simulated values. Such a beam splitter has been used for x-ray laser Michelson interferometry at 13.9 nm. The first interferogram is discussed

X-ray-ultraviolet beam splitters for the Michelson interferometer.

Science.gov (United States)

Delmotte, Franck; Ravet, Marie-Françoise; Bridou, Françoise; Varnière, Françoise; Zeitoun, Philippe; Hubert, Sébastien; Vanbostal, Laurent; Soullie, Gérard

2002-10-01

With the aim of realizing a Michelson interferometer working at 13.9 nm, we have developed a symmetrical beam splitter with multilayers deposited on the front and back sides of a silicon nitride membrane. On the basis of the experimental optical properties of the membrane, simulations have been performed to define the multilayer structure that provides the highest reflectivity-transmission product. Optimized Mo-Si multilayers have been successfully deposited on both sides of t he membrane by use of the ion-beam sputtering technique, with a thickness-period reproducibility of 0.1 nm. Measurements by means of synchrotron radiation at 13.9 nm and at an angle of 45 degrees provide a reflectivity of 14.2% and a transmission of 15.2% for a 60% s-polarized light, close to the simulated values. Such a beam splitter has been used for x-ray laser Michelson interferometry at 13.9 nm. The first interferogram is discussed.

Characteristics of OTFTs based on α-ω- Dihexyl-sexithiophene(DH6T) using Organic Molecular Beam Deposition

International Nuclear Information System (INIS)

Han, Dae Hee; Park, Byung Eun

2011-01-01

We fabricated an organic thin film transistor using organic semiconductor material α-ω- Dihexyl-sexithiophene (DH6T). The organic semiconductor was deposited using organic molecular beam deposition (OMBD). The deposition rate was 0.3A/s and the final thickness was 100 nm. After deposition, we annealed at 40 deg. C, 60 deg. C, 80 deg. C. In present, DH6T was used as a p-type semiconductor, so we measured 0V∼-40V. We measured drain current versus drain voltage, drain current versus gate voltage, calculated mobility and On/Off ratio at 40 deg. C, 60 deg. C, 80 deg. C. The field-effect mobility was 8x10- 3 , 9x10- 3 , 1.2x10- 2 , and on/off ratio was 1.75x10- 2 , 1.85x10- 2 , 2.17x10- 2 , respectively.

Synthesis of conductive semi-transparent silver films deposited by a Pneumatically-Assisted Ultrasonic Spray Pyrolysis Technique

Energy Technology Data Exchange (ETDEWEB)

Zaleta-Alejandre, E.; Balderas-Xicoténcatl, R. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico); Arrieta, M.L. Pérez [Universidad Autónoma de Zacatecas, Unidad Académica de Física, Calzada Solidaridad esq. Paseo, La Bufa s/n, C.P. 98060, Zacatecas, México (Mexico); Meza-Rocha, A.N.; Rivera-Álvarez, Z. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico); Falcony, C., E-mail: cfalcony@fis.cinvestav.mx [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico)

2013-10-01

Highlights: • We deposited metallic silver films without post-deposition annealing. • The spray pyrolysis technique is of low cost and scalable for industrial applications. • We obtained deposition rate of 60 nm min{sup −1} at 300 °C. • The average resistivity was 1E−7 Ω m. • Semi-transparent silver films were obtained at 350 °C and deposition time of 45 s. -- Abstract: The synthesis and characterization of nanostructured silver films deposited on corning glass by a deposition technique called Pneumatically-Assisted Ultrasonic Spray Pyrolysis are reported. Silver nitrate and triethanolamine were used as silver precursor and reducer agent, respectively. The substrate temperatures during deposition were in the range of 300–450 °C and the deposition times from 30 to 240 s. The deposited films are polycrystalline with cubic face-centered structure, and crystalline grain size less than 30 nm. Deposition rates up to 600 Å min{sup −1} were obtained at substrate temperature as low as 300 °C. The electrical, optical, and morphological properties of these films are also reported. Semi-transparent conductive silver films were obtained at 350 °C with a deposition time of 45 s.

Synthesis of conductive semi-transparent silver films deposited by a Pneumatically-Assisted Ultrasonic Spray Pyrolysis Technique

International Nuclear Information System (INIS)

Zaleta-Alejandre, E.; Balderas-Xicoténcatl, R.; Arrieta, M.L. Pérez; Meza-Rocha, A.N.; Rivera-Álvarez, Z.; Falcony, C.

2013-01-01

Highlights: • We deposited metallic silver films without post-deposition annealing. • The spray pyrolysis technique is of low cost and scalable for industrial applications. • We obtained deposition rate of 60 nm min −1 at 300 °C. • The average resistivity was 1E−7 Ω m. • Semi-transparent silver films were obtained at 350 °C and deposition time of 45 s. -- Abstract: The synthesis and characterization of nanostructured silver films deposited on corning glass by a deposition technique called Pneumatically-Assisted Ultrasonic Spray Pyrolysis are reported. Silver nitrate and triethanolamine were used as silver precursor and reducer agent, respectively. The substrate temperatures during deposition were in the range of 300–450 °C and the deposition times from 30 to 240 s. The deposited films are polycrystalline with cubic face-centered structure, and crystalline grain size less than 30 nm. Deposition rates up to 600 Å min −1 were obtained at substrate temperature as low as 300 °C. The electrical, optical, and morphological properties of these films are also reported. Semi-transparent conductive silver films were obtained at 350 °C with a deposition time of 45 s

Ion-beam texturing of uniaxially textured Ni films

International Nuclear Information System (INIS)

Park, S.J.; Norton, D.P.; Selvamanickam, Venkat

2005-01-01

The formation of biaxial texture in uniaxially textured Ni thin films via Ar-ion irradiation is reported. The ion-beam irradiation was not simultaneous with deposition. Instead, the ion beam irradiates the uniaxially textured film surface with no impinging deposition flux, which differs from conventional ion-beam-assisted deposition. The uniaxial texture is established via a nonion beam process, with the in-plane texture imposed on the uniaxial film via ion beam bombardment. Within this sequential ion beam texturing method, grain alignment is driven by selective etching and grain overgrowth

A comparative study of two advanced spraying techniques for the deposition of biologically active enzyme coatings onto bone-substituting implants

International Nuclear Information System (INIS)

Jonge, Lise T. de; Ju, J.; Leeuwenburgh, S.C.G.; Yamagata, Y.; Higuchi, T.; Wolke, J.G.C.; Inoue, K.; Jansen, J.A.

2010-01-01

Surface modification of implant materials with biomolecule coatings is of high importance to improve implant fixation in bone tissue. In the current study, we present two techniques for the deposition of biologically active enzyme coatings onto implant materials. The well-established thin film ElectroSpray Deposition (ESD) technique was compared with the SAW-ED technique that combines high-frequency Surface Acoustic Wave atomization with Electrostatic Deposition. By immobilizing the enzyme alkaline phosphatase (ALP) onto implant surfaces, the influence of both SAW-ED and ESD deposition parameters on ALP deposition efficiency and ALP biological activity was investigated. ALP coatings with preserved enzyme activity were deposited by means of both the SAW-ED and ESD technique. The advantages of SAW-ED over ESD include the possibility to spray highly conductive protein solutions, and the 60-times faster deposition rate. Furthermore, significantly higher deposition efficiencies were observed for the SAW-ED technique compared to ESD. Generally, it was shown that protein inactivation is highly dependent on both droplet dehydration and the applied electrical field strength. The current study shows that SAW-ED is a versatile and flexible technique for the fabrication of functionally active biomolecule coatings.

Matrix shaped pulsed laser deposition: New approach to large area and homogeneous deposition

Energy Technology Data Exchange (ETDEWEB)

Akkan, C.K.; May, A. [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany); Hammadeh, M. [Department for Obstetrics, Gynecology and Reproductive Medicine, IVF Laboratory, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Abdul-Khaliq, H. [Clinic for Pediatric Cardiology, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Aktas, O.C., E-mail: cenk.aktas@inm-gmbh.de [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany)

2014-05-01

Pulsed laser deposition (PLD) is one of the well-established physical vapor deposition methods used for synthesis of ultra-thin layers. Especially PLD is suitable for the preparation of thin films of complex alloys and ceramics where the conservation of the stoichiometry is critical. Beside several advantages of PLD, inhomogeneity in thickness limits use of PLD in some applications. There are several approaches such as rotation of the substrate or scanning of the laser beam over the target to achieve homogenous layers. On the other hand movement and transition create further complexity in process parameters. Here we present a new approach which we call Matrix Shaped PLD to control the thickness and homogeneity of deposited layers precisely. This new approach is based on shaping of the incoming laser beam by a microlens array and a Fourier lens. The beam is split into much smaller multi-beam array over the target and this leads to a homogenous plasma formation. The uniform intensity distribution over the target yields a very uniform deposit on the substrate. This approach is used to deposit carbide and oxide thin films for biomedical applications. As a case study coating of a stent which has a complex geometry is presented briefly.

Beam synchronous detection techniques for X-Ray spectroscopy

International Nuclear Information System (INIS)

Goujon, Gérard; Rogalev, Andreï; Goulon, José; Feite, Serge; Wilhelm, Fabrice

2013-01-01

The Photo diode detectors combine a set of properties that make them most appropriate, in particular, for X-ray Magnetic Circular Dichroism (XMCD) experiments. Under standard operating conditions, the detection bandwidth is primarily limited by the transimpedance preamplifier that converts the very low ac photocurrent into a voltage. On the other hand, when the photodiode is reverse biased, its finite shunt resistance will cause an undesirable, temperature dependent DC dark current. The best strategy to get rid of it is to use synchronous detection techniques. A classical implementation is based on the use of a chopper modulating the X-ray beam intensity at rather low frequencies (typically below 1 kHz). Here we report on the recent development of a fast Xray detection which has the capability to fully exploit the frequency structure of the ESRF X-ray beam (355 KHz and its harmonics). The availability of new wide band preamplifiers allowed us to extend the working frequency range up to a few MHz. A beam synchronous data processing was implemented in large FPGAs. Performances of the new detection system implemented at the ESRF beamline ID12 are illustrated with detection of the Fe K-edge XMCD spectra in garnets, using 4 bunches operation mode with modulation frequency of 1.4 MHz.

Impact of post deposition annealing in the electrically active traps at the interface between Ge(001) substrates and LaGeO{sub x} films grown by molecular beam deposition

Energy Technology Data Exchange (ETDEWEB)

Molle, Alessandro [Laboratorio MDM, CNR-IMM, via C. Olivetti 2, Agrate Brianza (MB) I-20864 (Italy); Baldovino, Silvia; Fanciulli, Marco [Laboratorio MDM, CNR-IMM, via C. Olivetti 2, Agrate Brianza (MB) I-20864 (Italy); Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano Bicocca, Milano (Italy); Tsoutsou, Dimitra; Golias, Evangelos; Dimoulas, Athanasios [MBE Laboratory, Institute of Materials Science, NCSR DEMOKRITOS, Athens 153 10 (Greece)

2011-10-15

Changes in the electron trapping at the interface between Ge substrates and LaGeO{sub x} films grown by atomic O assisted molecular beam deposition are inferred upon post deposition annealing treatment on the as-deposited films from electrically detected magnetic resonance (EDMR) spectroscopy and from the electrical response of Pt/LaGeO{sub x}/Ge metal oxide semiconductor (MOS) capacitors. The improved electrical performance of the MOS capacitors upon annealing is consistent with the EDMR detected reduction of oxide defects which are associated with GeO species in the LaGeO{sub x} layer as evidenced by x-ray photoelectron spectroscopy.

Optimization of ion assist beam deposition of magnesium oxide template films during initial nucleation and growth

Energy Technology Data Exchange (ETDEWEB)

Groves, James R [Los Alamos National Laboratory; Matias, Vladimir [Los Alamos National Laboratory; Stan, Liliana [Los Alamos National Laboratory; De Paula, Raymond F [Los Alamos National Laboratory; Hammond, Robert H [STANFORD UNIV.; Clemens, Bruce M [STANFOED UNIV.

2010-01-01

Recent efforts in investigating the mechanism of ion beam assisted deposition (IBAD) of biaxially textured thin films of magnesium oxide (MgO) template layers have shown that the texture develops suddenly during the initial 2 nm of deposition. To help understand and tune the behavior during this initial stage, we pre-deposited thin layers of MgO with no ion assist prior to IBAD growth of MgO. We found that biaxial texture develops for pre-deposited thicknesses < 2 nm, and that the thinnest layer tested, at 1 nm, resulted in the best qualitative RHEED image, indicative of good biaxial texture development. The texture developed during IBAD growth on the 1.5 nm pre-deposited layer is slightly worse and IBAD growth on the 2 nm pre-deposited layer produces a fiber texture. Application of these layers on an Al{sub 2}O{sub 3} starting surface, which has been shown to impede texture development, improves the overall quality of the IBAD MgO and has some of the characteristics of a biaxially texture RHEED pattern. It is suggested that the use of thin (<2 nm) pre-deposited layers may eliminate the need for bed layers like Si{sub 3}N{sub 4} and Y{sub 2}O{sub 3} that are currently thought to be required for proper biaxial texture development in IBAD MgO.

Power deposition by neutral beam injected fast ions in field-reversed configurations

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasawa, Naotaka

2004-01-01

The effects of Coulomb collisions on neutral beam (NB) injected fast ions into field-reversed configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing-down and pitch-angle collisions. The Monte Carlo method is used for the pitch-angle scattering, and the friction term is added to the equation of motion to show the effects of the slowing-down collision, such as the deposited power profile. The calculation parameters used are relevant to the NB injection on the FRC injection experiment device [T. Asai, Y. Suzuki, T. Yoneda, F. Kodera, M. Okubo, and S. Goto, Phys. Plasmas 7, 2294 (2000)]. It is found that the dominant local power deposition occurs in the open field region between the X point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch-angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found to be negligible. The loss mechanism due to nonadiabatic fast ion motion, which is intrinsic in nonuniform FRC plasmas, has a much greater effect than the pitch-angle scattering by Coulomb collision

Measurements of absorbed energy distributions in water from pulsed electron beams

International Nuclear Information System (INIS)

Devanney, J.A.

1974-01-01

An evaluation of the use of a holographic interferometer to measure the energy deposition as a function of depth in water from pulsed electron beams, together with a brief description of the interferometer and the technique of generating a hologram are presented. The holographic interferometer is used to measure the energy deposition as a function of depth in water from various pulsed beams of monoenergetic electrons in the energy range from 1.0 to 2.5 MeV. These results are compared to those computed by using a Monte Carlo radiation transport code, ETRAN-15, for the same electron energies. After the discrepancies between the measured and computed results are evaluated, reasonable agreement is found between the measured and computed absorbed energy distributions as a function of depth in water. An evalutation of the response of the interferometer as a function of electron intensities is performed. A comparison among four energy deposition curves that result from the irradiation of water with pulsed electron beams from a Febetron accelerator, model 705, is presented. These pulsed beams were produced by the same vacuum diode with the same charging voltage. The results indicate that the energy distribution of the electrons in the pulsed beam is not always constant. A comparison of the energy deposition curves that result from the irradiation of water with electron pulses from different vacuum diodes but the same charging voltage is presented. These results indicate again that the energy distribution of the electrons in the pulsed beam may vary between vacuum diodes. These differences would not be realized by using a totally absorbing metal calorimeter and Faraday Cup

Implementation of intra-cavity beam shaping technique to enhance pump efficiency

CSIR Research Space (South Africa)

Litvin, IA

2012-02-01

Full Text Available In this work the author proposes an implementation of a new intra-cavity beam shaping technique to vary the intensity distribution of the fundamental mode in a resonator cavity while maintaining a constant intensity distribution at the output...

Uranium solution mining cost estimating technique: means for rapid comparative analysis of deposits

International Nuclear Information System (INIS)

Anon.

1978-01-01

Twelve graphs provide a technique for determining relative cost ranges for uranium solution mining projects. The use of the technique can provide a consistent framework for rapid comparative analysis of various properties of mining situations. The technique is also useful to determine the sensitivities of cost figures to incremental changes in mining factors or deposit characteristics

Impact of high temperature and short period annealing on SnS films deposited by E-beam evaporation

International Nuclear Information System (INIS)

Gedi, Sreedevi; Reddy, Vasudeva Reddy Minnam; Kang, Jeong-yoon; Jeon, Chan-Wook

2017-01-01

Highlights: • Preparation SnS films using electron beam evaporation at room temperature. • SnS films were annealed at a high temperaure for different short period of times. • The films showed highly oriented (111) planes with orthorhombic crystal structure. • Surface morphology showed bigger and faceted grains embedded in orthorombic. • The TEM confirmed that big orthorombic slabs had single-crystalline nature. - Abstract: Thin films of SnS were deposited on Mo-substrate using electron beam evaporation at room temperature. As-deposited SnS films were annealed at a constant high temperaure of 860 K for different short period of times, 1 min, 3 min, and 5 min. The impact of heat treatment period on the physical properties of SnS films was investigated using appropriate characterization tools. XRD analysis revealed that the films were highly oriented along (111) plane with orthorhombic crystal structure. Surface morphology of as-deposited SnS films showed an identical leaf texture where as the annealed films showed large orthorombic slab shape grains in adidition to the leaf shape grains, which indicates the significance of short period annealing at high temperature. The transmission electron microscopy confirmed that those large orthorombic slabs had single-crystalline nature. The results emphasized that the short period annealing treatment at high temperature stimulated the growth of film towards the single crystallinity.

Impact of high temperature and short period annealing on SnS films deposited by E-beam evaporation

Energy Technology Data Exchange (ETDEWEB)

Gedi, Sreedevi; Reddy, Vasudeva Reddy Minnam; Kang, Jeong-yoon; Jeon, Chan-Wook, E-mail: cwjeon@ynu.ac.kr

2017-04-30

Highlights: • Preparation SnS films using electron beam evaporation at room temperature. • SnS films were annealed at a high temperaure for different short period of times. • The films showed highly oriented (111) planes with orthorhombic crystal structure. • Surface morphology showed bigger and faceted grains embedded in orthorombic. • The TEM confirmed that big orthorombic slabs had single-crystalline nature. - Abstract: Thin films of SnS were deposited on Mo-substrate using electron beam evaporation at room temperature. As-deposited SnS films were annealed at a constant high temperaure of 860 K for different short period of times, 1 min, 3 min, and 5 min. The impact of heat treatment period on the physical properties of SnS films was investigated using appropriate characterization tools. XRD analysis revealed that the films were highly oriented along (111) plane with orthorhombic crystal structure. Surface morphology of as-deposited SnS films showed an identical leaf texture where as the annealed films showed large orthorombic slab shape grains in adidition to the leaf shape grains, which indicates the significance of short period annealing at high temperature. The transmission electron microscopy confirmed that those large orthorombic slabs had single-crystalline nature. The results emphasized that the short period annealing treatment at high temperature stimulated the growth of film towards the single crystallinity.

Nanoscale Soldering of Positioned Carbon Nanotubes using Highly Conductive Electron Beam Induced Gold Deposition

DEFF Research Database (Denmark)

Madsen, Dorte Nørgaard; Mølhave, Kristian; Mateiu, Ramona Valentina

2003-01-01

We have developed an in-situ method for controlled positioning of carbon nanotubes followed by highly conductive contacting of the nanotubes, using electron beam assisted deposition of gold. The positioning and soldering process takes place inside an Environmental Scanning Electron Microscope (E...... in a carbon matrix. Nanoscale soldering of multi-walled carbon nanotubes (MWNT) onto microelectrodes was achieved by deposition of a conducting gold line across a contact point between nanotube and electrode. The solderings were found to be mechanically stronger than the carbon nanotubes. We have positioned...... MWNTs to bridge the gap between two electrodes, and formed soldering bonds between the tube and each of the electrodes. All nanotube bridges showed ohmic resistances in the range 10-30 kΩ. We observed no increase in resistance after exposing the MWNT bridge to air for days....

Deposition of high Tc superconductor thin films by pulsed excimer laser ablation and their post-synthesis processing

International Nuclear Information System (INIS)

Ogale, S.B.

1992-01-01

This paper describes the use of pulsed excimer laser ablation technique for deposition of high quality superconductor thin films on different substrate materials such as Y stabilized ZrO 2 , SrTiO 3 , LiNbO 3 , Silicon and Stainless Steels, and dopant incorporation during the film depositions. Processing of deposited films using ion and laser beams for realisation of device features are presented. 28 refs., 16 figs

Geochemical Exploration Techniques Applicable in the Search for Copper Deposits

Science.gov (United States)

Chaffee, Maurice A.

1975-01-01

Geochemical exploration is an important part of copper-resource evaluation. A large number of geochemical exploration techniques, both proved and untried, are available to the geochemist to use in the search for new copper deposits. Analyses of whole-rock samples have been used in both regional and local geochemical exploration surveys in the search for copper. Analyses of mineral separates, such as biotite, magnetite, and sulfides, have also been used. Analyses of soil samples are widely used in geochemical exploration, especially for localized surveys. It is important to distinguish between residual and transported soil types. Orientation studies should always be conducted prior to a geochemical investigation in a given area in order to determine the best soil horizon and the best size of soil material for sampling in that area. Silty frost boils, caliche, and desert varnish are specialized types of soil samples that might be useful sampling media. Soil gas is a new and potentially valuable geochemical sampling medium, especially in exploring for buried mineral deposits in arid regions. Gaseous products in samples of soil may be related to base-metal deposits and include mercury vapor, sulfur dioxide, hydrogen sulfide, carbon oxysulfide, carbon dioxide, hydrogen, oxygen, nitrogen, the noble gases, the halogens, and many hydrocarbon compounds. Transported materials that have been used in geochemical sampling programs include glacial float boulders, glacial till, esker gravels, stream sediments, stream-sediment concentrates, and lake sediments. Stream-sediment sampling is probably the most widely used and most successful geochemical exploration technique. Hydrogeochemical exploration programs have utilized hot- and cold-spring waters and their precipitates as well as waters from lakes, streams, and wells. Organic gel found in lakes and at stream mouths is an unproved sampling medium. Suspended material and dissolved gases in any type of water may also be useful

Techniques for fabricating an infrared optical pyrometry system for pulsed electron beam diagnostics

International Nuclear Information System (INIS)

Ouellette, A.L.

1976-01-01

A description is given of an infrared optical pyrometry system which was designed to make fast time resolved temperature measurements. The purpose of this equipment is to determine the amount of energy from an electron beam or some other type of pulsed energy deposition that is absorbed in a target. The system is capable of measuring energy deposition levels up to 4000 J/g in carbon, which corresponds to a graphite target temperature of 2200 0 C. Methods of fabrication, alignment, and calibration are presented. The measurement of absorbed energy in a target as a function of position and depth is discussed as a possible application, and several measurements are described which permit a comparison of results from this system with those taken by other methods

A new crossed molecular beam apparatus using time-sliced ion velocity imaging technique

International Nuclear Information System (INIS)

Wu Guorong; Zhang Weiqing; Pan Huilin; Shuai Quan; Jiang Bo; Dai Dongxu; Yang Xueming

2008-01-01

A new crossed molecular beam apparatus has been constructed for investigating polyatomic chemical reactions using the time-sliced ion velocity map imaging technique. A unique design is adopted for one of the two beam sources and allows us to set up the molecular beam source either horizontally or vertically. This can be conveniently used to produce versatile atomic or radical beams from photodissociation and as well as electric discharge. Intensive H-atom beam source with high speed ratio was produced by photodissociation of the HI molecule and was reacted with the CD 4 molecule. Vibrational-state resolved HD product distribution was measured by detecting the CD 3 product. Preliminary results were also reported on the F+SiH 4 reaction using the discharged F atom beam. These results demonstrate that this new instrument is a powerful tool for investigating chemical dynamics of polyatomic reactions.

Annealing dependence of residual stress and optical properties of TiO2 thin film deposited by different deposition methods.

Science.gov (United States)

Chen, Hsi-Chao; Lee, Kuan-Shiang; Lee, Cheng-Chung

2008-05-01

Titanium oxide (TiO(2)) thin films were prepared by different deposition methods. The methods were E-gun evaporation with ion-assisted deposition (IAD), radio-frequency (RF) ion-beam sputtering, and direct current (DC) magnetron sputtering. Residual stress was released after annealing the films deposited by RF ion-beam or DC magnetron sputtering but not evaporation, and the extinction coefficient varied significantly. The surface roughness of the evaporated films exceeded that of both sputtered films. At the annealing temperature of 300 degrees C, anatase crystallization occurred in evaporated film but not in the RF ion-beam or DC magnetron-sputtered films. TiO(2) films deposited by sputtering were generally more stable during annealing than those deposited by evaporation.

Challenges of fabricating plasmonic and photonic structures with Neon ion beam milling

DEFF Research Database (Denmark)

Leißner, Till; Fiutowski, Jacek; Bozhevolnyi, Sergey I.

-established electron beam lithography and focussed ion beam milling (FIB) using Gallium ions. These techniques, however, are to some extend limited in their resolution, and in addition Gallium and Carbon are implanted and deposited into the plasmonic structures during FIB process, potentially changing plasmonic...... properties. We are currently studying the capabilities of focussed Helium and Neon ion beam milling for the fabricating of plasmonic and photonic devices. We found that Neon ion beam milling enables us to prepare plasmonic structures, such as trenches (see Fig. 1) and V-grooves without doping and alloying...... effects specific to Galium FIB. Neon FIB milling is superior to Helium FIB milling in terms of the processing speed and smaller levels of implanted ions. From our perspective it is the most promising technique for the fabrication of individual plasmonic devices with a few nanometers precision. The main...

The application of Lie algebra techniques to beam transport design

International Nuclear Information System (INIS)

Irwin, J.

1990-01-01

Using a final focus system for high-energy linear colliders as an example of a beam transport system, we illustrate for each element, and for the interplay of elements, the connection of Lie algebra techniques with usual optical analysis methods. Our analysis describes, through fourth order, the calculation and compensation of all important aberrations. (orig.)

Electron beam physical vapor deposition of thin ruby films for remote temperature sensing

International Nuclear Information System (INIS)

Li Wei; Coppens, Zachary J.; Greg Walker, D.; Valentine, Jason G.

2013-01-01

Thermographic phosphors (TGPs) possessing temperature-dependent photoluminescence properties have a wide range of uses in thermometry due to their remote access and large temperature sensitivity range. However, in most cases, phosphors are synthesized in powder form, which prevents their use in high resolution micro and nanoscale thermal microscopy. In the present study, we investigate the use of electron beam physical vapor deposition to fabricate thin films of chromium-doped aluminum oxide (Cr-Al 2 O 3 , ruby) thermographic phosphors. Although as-deposited films were amorphous and exhibited weak photoluminescence, the films regained the stoichiometry and α-Al 2 O 3 crystal structure of the combustion synthesized source powder after thermal annealing. As a consequence, the annealed films exhibit both strong photoluminescence and a temperature-dependent lifetime that decreases from 2.9 ms at 298 K to 2.1 ms at 370 K. Ruby films were also deposited on multiple substrates. To ensure a continuous film with smooth surface morphology and strong photoluminescence, we use a sapphire substrate, which is thermal expansion coefficient and lattice matched to the film. These thin ruby films can potentially be used as remote temperature sensors for probing the local temperatures of micro and nanoscale structures.

Synthesis and analysis of gold nanoclusters on silicon substrates by ion beams

International Nuclear Information System (INIS)

Sood, D.K.; Venkatachalam, D.K.; Bhargava, S.K.; Evans, P.J.

2005-01-01

To facilitate the growth of silica nanowires on silicon substrates, two different seeding techniques: 1) ion implantation and 2) chemical deposition of as-synthesised gold colloids have been compared for the formation of catalysing gold nanoclusters. The prepared substrates of both types were analysed using Rutherford backscattering spectrometry at ANSTO to determine the amount of gold and its depth distribution. The topography of the substrates deposited with chemically synthesised gold nanoparticles were studied under SEM. The preliminary ion beam (RBS) analysis has shown ion implantation as a novel technique for seeding Au nanoclusters on silicon substrates facilitating growth of nanowires. This method holds a great potential for using any metal across the periodic table that can act as catalysing seed nanoclusters for nanowire growth. The use of chemical deposition as a seeding technique to deposit as-synthesised gold nanoparticles requires further investigations. RBS results show significant difference in the depth distribution of the gold nanoparticles on silicon substrates seeded by two different techniques. (author). 6 refs., 4 figs

Influence of substrate temperature and annealing on structural and optical properties of TiO{sub 2} films deposited by reactive e-beam evaporation

Energy Technology Data Exchange (ETDEWEB)

Pjević, D., E-mail: dejanp@vinca.rs [VINČA Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001 Belgrade (Serbia); Marinković, T.; Savić, J.; Bundaleski, N.; Obradović, M.; Milosavljević, M. [VINČA Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001 Belgrade (Serbia); Kulik, M. [Frank Laboratory of Neutron Physics, JINR, Joliot-Curie St. 6, Dubna 141980, Moscow Region (Russian Federation)

2015-09-30

The influence of deposition and post-deposition annealing parameters on the structure and optical properties of TiO{sub 2} thin films synthesized by reactive e-beam evaporation is reported. Pure Ti (99.9%) was evaporated in oxygen atmosphere to form thin films on Si (100) and glass substrates. Depositions were conducted on substrates held at room temperature and at 200–400 °C heated substrates. Post-deposition annealing was done for 3 h at 500 °C in air. Compositional and structural studies were performed by Rutherford backscattering spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy, and optical properties were studied by ultraviolet–visible spectroscopy and analytically by pointwise unconstrained minimization approach method. It was found that both the structure and optical properties of the films are strongly influenced by the deposition and processing parameters. All deposited samples showed good stoichiometry of Ti:O ~ 1:2. Depending on the substrate temperature and oxygen pressure in the chamber during the deposition, anatase–rutile mixed films were obtained, and in some cases TiO and Ti{sub 2}O{sub 3} phases were observed. Substrate deposition temperature appears to play the major role on the final structure of the films, while post-deposition annealing adds up for the lack of oxygen in some cases and invokes crystal grain growth of already initiated phases. The results can be interesting towards the development of TiO{sub 2} thin films with defined structure and optical properties. - Highlights: • TiO{sub 2} films were deposited by reactive e-beam evaporation. • Structure and properties were studied as a function of deposition temperature. • Stoichiometry of as-deposited films was Ti:O ~ 1:2, containing different Ti-O phases. • Post-deposition annealing yielded phase transformation, affecting the properties. • Refractive index increases with the substrate deposition temperature.

Tracing the plasma interactions for pulsed reactive crossed-beam laser ablation

Science.gov (United States)

Chen, Jikun; Stender, Dieter; Pichler, Markus; Döbeli, Max; Pergolesi, Daniele; Schneider, Christof W.; Wokaun, Alexander; Lippert, Thomas

2015-10-01

Pulsed reactive crossed-beam laser ablation is an effective technique to govern the chemical activity of plasma species and background molecules during pulsed laser deposition. Instead of using a constant background pressure, a gas pulse with a reactive gas, synchronized with the laser beam, is injected into vacuum or a low background pressure near the ablated area of the target. It intercepts the initially generated plasma plume, thereby enhancing the physicochemical interactions between the gaseous environment and the plasma species. For this study, kinetic energy resolved mass-spectrometry and time-resolved plasma imaging were used to study the physicochemical processes occurring during the reactive crossed beam laser ablation of a partially 18O substituted La0.6Sr0.4MnO3 target using oxygen as gas pulse. The characteristics of the ablated plasma are compared with those observed during pulsed laser deposition in different oxygen background pressures.

Epitaxial GaN films by hyperthermal ion-beam nitridation of Ga droplets

Energy Technology Data Exchange (ETDEWEB)

Gerlach, J. W.; Ivanov, T.; Neumann, L.; Hoeche, Th.; Hirsch, D.; Rauschenbach, B. [Leibniz-Institut fuer Oberflaechenmodifizierung (IOM), D-04318 Leipzig (Germany)

2012-06-01

Epitaxial GaN film formation on bare 6H-SiC(0001) substrates via the process of transformation of Ga droplets into a thin GaN film by applying hyperthermal nitrogen ions is investigated. Pre-deposited Ga atoms in well defined amounts form large droplets on the substrate surface which are subsequently nitridated at a substrate temperature of 630 Degree-Sign C by a low-energy nitrogen ion beam from a constricted glow-discharge ion source. The Ga deposition and ion-beam nitridation process steps are monitored in situ by reflection high-energy electron diffraction. Ex situ characterization by x-ray diffraction and reflectivity techniques, Rutherford backscattering spectrometry, and electron microscopy shows that the thickness of the resulting GaN films depends on the various amounts of pre-deposited gallium. The films are epitaxial to the substrate, exhibit a mosaic like, smooth surface topography and consist of coalesced large domains of low defect density. Possible transport mechanisms of reactive nitrogen species during hyperthermal nitridation are discussed and the formation of GaN films by an ion-beam assisted process is explained.

Techniques to sort Bessel beams

CSIR Research Space (South Africa)

Dudley, Angela L

2013-09-01

Full Text Available -polar coordinate transformation, translating helically phased beams into a transverse phase gradient. By introducing two cylindrical lenses we can focus each of the azimuthal modes associated with each Bessel beam to a different lateral position in the Fourier...

Broadband infrared beam splitter for spaceborne interferometric infrared sounder.

Science.gov (United States)

Yu, Tianyan; Liu, Dingquan; Qin, Yang

2014-10-01

A broadband infrared beam splitter (BS) on ZnSe substrate used for the spaceborne interferometric infrared sounder (SIIRS) is studied in the spectral range of 4.44-15 μm. Both broadband antireflection coating and broadband beam-splitter coating in this BS are designed and tested. To optimize the optical properties and the stability of the BS, suitable infrared materials were selected, and improved deposition techniques were applied. The designed structures matched experimental data well, and the properties of the BS met the application specification of SIIRS.

Neutral atom beam technique enhances bioactivity of PEEK

International Nuclear Information System (INIS)

Khoury, Joseph; Kirkpatrick, Sean R.; Maxwell, Melissa; Cherian, Raymond E.; Kirkpatrick, Allen; Svrluga, Richard C.

2013-01-01

Polyetheretherketone (PEEK) is currently gaining popularity in orthopedic and spinal applications but has potential drawbacks in use. PEEK is biocompatible, similar in elasticity to bone, and radiolucent; however, it has been shown to be inert and does not integrate well with bone. Recent efforts have focused on increasing the bioactivity of PEEK by modifying the surface to improve the bone-implant interface. We have employed a novel Accelerated Neutral Atom Beam technique (ANAB) to enhance the bioactivity of PEEK. ANAB employs an intense beam of cluster-like packets of accelerated unbonded neutral argon (Ar) gas atoms. These beams are created by first producing a highly energetic Gas Cluster Ion Beam (GCIB) comprised of van der Waals bonded Ar atoms, then transferring energy to the clusters so as to cause release of most of the interatomic bonds, and finally deflecting away the remaining electrically charged cluster cores of still bonded atoms. We identified that ANAB treatment of PEEK results in nanometer scale surface modifications as well as increased surface hydrophilicity. Human osteoblasts seeded onto the surface of ANAB-treated PEEK exhibited enhanced growth as compared to control PEEK as evidenced by cell proliferation assays and microscopy. This increase in bioactivity resulted in cell proliferation levels comparable to native titanium. An in vivo study using a rat calvarial critical size defect model revealed enhanced osseointegration where bone tissue formation was evident only on the ANAB treated PEEK. Taken together, these data suggest that ANAB treatment of PEEK has the potential to enhance its bioactivity, resulting in bone formation and significantly decreasing osseointegration time of orthopedic and spinal implants

Corrosion-resistant titanium nitride coatings formed on stainless steel by ion-beam-assisted deposition

International Nuclear Information System (INIS)

Baba, K.; Hatada, R.

1994-01-01

Titanium films 70nm thick were deposited on austenitic type 316L stainless steel substrates, and these specimens were irradiated with titanium ions of energy 70kV at a fluence of 1x10 17 ioncm -2 , using a metal vapor vacuum arc (MEVVA) IV metallic ion source at room temperature. After irradiation, titanium nitride (TiN) films were deposited by titanium evaporation and simultaneous irradiation by a nitrogen ion beam, with transport ratios of Ti to N atoms from 0.5 to 10.0 and an ion acceleration voltage of 2kV. The preferred orientation of the TiN films varied from left angle 200 right angle to left angle 111 right angle normal to the surface when the transport ratio was increased. With the help of Auger electron spectroscopy, interfacial mixing was verified. Nitrogen atoms were present in the state of titanium nitride for all transport ratios from 0.5 up to 10.0. However, the chemical bonding state of titanium changed from titanium nitride to the metallic state with increasing transport ratio Ti/N. The corrosion behavior was evaluated in an aqueous solution of sulfuric acid saturated with oxygen, using multisweep cyclic voltammetry measurements. Thin film deposition of pure titanium and titanium implantation prior to TiN deposition have beneficial effects on the suppression of transpassive chromium dissolution. ((orig.))

Effects of beam, target and substrate potentials in ion beam processing

International Nuclear Information System (INIS)

Harper, J.M.E.

1982-01-01

Ion beam etching and deposition are normally carried out with beam, target and substrate potentials near ground potential. In this paper, the effects of intentional or unintentional changes in these potentials are described. Examples include beam neutralization, a single extraction grid, substrate bias, and target bias. Each example is described in terms of beam plasma parameters. (Auth.)

Energy deposition evaluation for ultra-low energy electron beam irradiation systems using calibrated thin radiochromic film and Monte Carlo simulations

Energy Technology Data Exchange (ETDEWEB)

Matsui, S., E-mail: smatsui@gpi.ac.jp; Mori, Y. [The Graduate School for the Creation of New Photonics Industries, 1955-1 Kurematsucho, Nishiku, Hamamatsu, Shizuoka 431-1202 (Japan); Nonaka, T.; Hattori, T.; Kasamatsu, Y.; Haraguchi, D.; Watanabe, Y.; Uchiyama, K.; Ishikawa, M. [Hamamatsu Photonics K.K. Electron Tube Division, 314-5 Shimokanzo, Iwata, Shizuoka 438-0193 (Japan)

2016-05-15

For evaluation of on-site dosimetry and process design in industrial use of ultra-low energy electron beam (ULEB) processes, we evaluate the energy deposition using a thin radiochromic film and a Monte Carlo simulation. The response of film dosimeter was calibrated using a high energy electron beam with an acceleration voltage of 2 MV and alanine dosimeters with uncertainty of 11% at coverage factor 2. Using this response function, the results of absorbed dose measurements for ULEB were evaluated from 10 kGy to 100 kGy as a relative dose. The deviation between the responses of deposit energy on the films and Monte Carlo simulations was within 15%. As far as this limitation, relative dose estimation using thin film dosimeters with response function obtained by high energy electron irradiation and simulation results is effective for ULEB irradiation processes management.

An x-ray technique for precision laser beam synchronization

International Nuclear Information System (INIS)

Landen, O.L.; Lerche, R.A.; Hay, R.G.; Hammel, B.A.; Kalantar, D.; Cable, M.D.

1994-01-01

A new x-ray technique for recording the relative arrival times of multiple laser beams at a common target with better than ± 10 ps accuracy has been implemented at the Nova laser facility. 100 ps, 3ω Nova beam are focused to separate locations on a gold ribbon target viewed from the side. The measurement consists of using well characterized re-entrant x-ray streak cameras for 1-dimensional streaked imaging of the > 3 keV x-rays emanating from these isolated laser plasmas. After making the necessary correction for the differential laser, x-ray and electron transit times involved, timing offsets as low as ± 7 ps are resolved, and on subsequent shots, corrected for, verified and independently checked. This level of synchronization proved critical in meeting the power balance requirements for indirectly-driven pulse-shaped Nova implosions

A layer correlation technique for pion energy calibration at the 2004 ATLAS Combined Beam Test

International Nuclear Information System (INIS)

Abat, E; Arik, E; Abdallah, J M; Addy, T N; Adragna, P; Aharrouche, M; Ahmad, A; Akesson, T P A; Aleksa, M; Anghinolfi, F; Baron, S; Alexa, C; Anderson, K; Andreazza, A; Banfi, D; Antonaki, A; Arabidze, G; Atkinson, T; Baines, J; Baker, O K

2011-01-01

A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of energy deposits in the calorimeter layers, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Geant4 Monte Carlo events and used to reconstruct the energy of pions impinging on the calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. For pion beams with energies between 20GeV and 180GeV, the particle energy is reconstructed within 3% and the energy resolution is improved by between 11% and 25% compared to the resolution at the electromagnetic scale.

A layer correlation technique for pion energy calibration at the 2004 ATLAS Combined Beam Test

Energy Technology Data Exchange (ETDEWEB)

Abat, E; Arik, E [Bogazici University, Faculty of Sciences, Department of Physics, TR - 80815 Bebek-Istanbul (Turkey); Abdallah, J M [Institut de Fisica d' Altes Energies, IFAE, Universitat Autonoma de Barcelona, Edifici Cn, ES - 08193 Bellaterra (Barcelona) Spain (Spain); Addy, T N [Hampton University, Department of Physics, Hampton, VA 23668 (United States); Adragna, P [Queen Mary, University of London, Mile End Road, E1 4NS, London (United Kingdom); Aharrouche, M [Universitaet Mainz, Institut fuer Physik, Staudinger Weg 7, DE 55099 (Germany); Ahmad, A [Insitute of Physics, Academia Sinica, TW - Taipei 11529, Taiwan (China); Akesson, T P A [Lunds universitet, Naturvetenskapliga fakulteten, Fysiska institutionen, Box 118, SE - 221 00, Lund (Sweden); Aleksa, M; Anghinolfi, F; Baron, S [European Laboratory for Particle Physics CERN, CH-1211 Geneva 23 (Switzerland); Alexa, C [National Institute of Physics and Nuclear Engineering (Bucharest -IFIN-HH), P.O. Box MG-6, R-077125 Bucharest (Romania); Anderson, K [University of Chicago, Enrico Fermi Institute, 5640 S. Ellis Avenue, Chicago, IL 60637 (United States); Andreazza, A; Banfi, D [INFN Sezione di Milano, via Celoria 16, IT - 20133 Milano (Italy); Antonaki, A; Arabidze, G [University of Athens, Nuclear and Particle Physics Department of Physics, Panepistimiopouli Zografou, GR 15771 Athens (Greece); Atkinson, T [School of Physics, University of Melbourne, AU - Parkvill, Victoria 3010 (Australia); Baines, J [Rutherford Appleton Laboratory, Science and Technology Facilities Council, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Baker, O K, E-mail: kjg@particle.kth.se [Yale University, Department of Physics , PO Box 208121, New Haven, CT06520-8121 (United States)

2011-06-15

A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of energy deposits in the calorimeter layers, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Geant4 Monte Carlo events and used to reconstruct the energy of pions impinging on the calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. For pion beams with energies between 20GeV and 180GeV, the particle energy is reconstructed within 3% and the energy resolution is improved by between 11% and 25% compared to the resolution at the electromagnetic scale.

Thin film deposition and characterization of pure and iron-doped electron-beam evaporated tungsten oxide for gas sensors

Energy Technology Data Exchange (ETDEWEB)

Tesfamichael, Tuquabo, E-mail: t.tesfamichael@qut.edu.a [Faculty of Built Environment and Engineering, School of Engineering Systems, Queensland University of Technology, 2 George Street, Brisbane, QLD 4000 (Australia); Arita, Masashi [Graduate School of Information Science and Technology, Hokkaido University, Kita-14, Nishi-9, Kita-ku, Sapporo, 060-0814 (Japan); Bostrom, Thor [Faculty of Science and Technology, School of Physical and Chemical Sciences, Queensland University of Technology, 2 George Street, Brisbane, QLD 4000 (Australia); Bell, John [Centre for Built Environment and Engineering Research, Queensland University of Technology, 2 George Street, Brisbane, QLD 4000 (Australia)

2010-06-30

Pure tungsten oxide (WO{sub 3}) and iron-doped (10 at.%) tungsten oxide (WO{sub 3}:Fe) nanostructured thin films were prepared using a dual crucible Electron Beam Evaporation (EBE) technique. The films were deposited at room temperature under high vacuum onto glass as well as alumina substrates and post-heat treated at 300 {sup o}C for 1 h. Using Raman spectroscopy the as-deposited WO{sub 3} and WO{sub 3}:Fe films were found to be amorphous, however their crystallinity increased after annealing. The estimated surface roughness of the films was similar (of the order of 3 nm) to that determined using Atomic Force Microscopy (AFM). As observed by AFM, the WO{sub 3}:Fe film appeared to have a more compact surface as compared to the more porous WO{sub 3} film. X-ray photoelectron spectroscopy analysis showed that the elemental stoichiometry of the tungsten oxide films was consistent with WO{sub 3}. A slight difference in optical band gap energies was found between the as-deposited WO{sub 3} (3.22 eV) and WO{sub 3}:Fe (3.12 eV) films. The differences in the band gap energies of the annealed films were significantly higher, having values of 3.12 eV and 2.61 eV for the WO{sub 3} and WO{sub 3}:Fe films respectively. The heat treated films were investigated for gas sensing applications using noise spectroscopy. It was found that doping of Fe to WO{sub 3} produced gas selectivity but a reduced gas sensitivity as compared to the WO{sub 3} sensor.

Deposition of porous cathodes using plasma spray technique for reduced-temperature SOFCs

Energy Technology Data Exchange (ETDEWEB)

Jankovic, J.; Hui, S.; Roller, J.; Kesler, O.; Xie, Y.; Maric, R.; Ghosh, D. [National Research Council of Canada, Vancouver, BC (Canada). Inst. for Fuel Cell Innovation

2005-07-01

Current techniques for Solid Oxide Fuel Cell (SOFC) materials deposition are often expensive and time-consuming. Plasma-spraying techniques provide higher deposition rates, short processing times and control over porosity and composition during deposition. Optimum plasma spraying for lanthanum based cathode materials were discussed. Plasma-spraying was used to deposit cathode materials onto ceramic and stainless steel substrates to obtain highly porous structures. Lanthanum cathode materials with composition of La{sub 0.6}Sr{sub 0.4}C{sub 0.2}Fe{sub 0.8}O{sub 3} were employed in the powder form. The powder was prepared from powder precursors with different power formers and binder levels, or from produced single-phase lanthanum powders. The (La{sub 0.8}Sr{sub 0.2}){sub 0.98}MnO{sub 3} cathode material was also processed for comparison purposes. The deposition process was developed to obtain coatings with good bond strength, porosity, film thickness and residual stresses. The phase and microstructure of deposited materials were characterized using X-Ray Diffraction and Scanning Electron Microscopy (SEM). It was concluded that good flow of the powder precursors is achieved by spraying 50-100 um particle size powders and using vibrating feeders. Further processing of the spraying powders was recommended. It was noted that oxide precursors showed greater reactivity among the precursors. The best precursor reactivity and coating morphology was obtained using 40 volume per cent of graphite pore former, incorporated into the precursor mixture during wet ball milling. It was concluded that higher power levels and larger distances between the plasma gun and the substrate result in coatings with the highest porosities and best phase compositions. 5 refs., 1 tab., 6 figs.

An apparatus for sequential pulsed plasma beam treatment in combination with Arc PVD deposition

International Nuclear Information System (INIS)

Stanislawski, J.; Werner, Z.; Piekoszewski, J.; Richter, E.

2002-01-01

A hybrid type of apparatus is described which enables one to form a thin multi-layer film on the surface of any kind of solid substrate. In one process, the surface is treated with a high intensity pulse plasma beam which introduces the chosen kind of atoms into the near-surface layer of the substrate. In the second process, following the first without breaking the vacuum, the coating is formed by arc PVD (physics vapour deposition) process. Two examples of coatings formed on metallic and ceramic substrates are presented. (author)

Numerical simulations of energy deposition caused by 50 MeV—50 TeV proton beams in copper and graphite targets

CERN Document Server

Nie, Y; Chetvertkova, V; Rosell-Tarrago, G; Burkart, F; Wollmann, D

2017-01-01

The conceptual design of the Future Circular Collider (FCC) is being carried out actively in an international collaboration hosted by CERN, for the post–Large Hadron Collider (LHC) era. The target center-of-mass energy of proton-proton collisions for the FCC is 100 TeV, nearly an order of magnitude higher than for LHC. The existing CERN accelerators will be used to prepare the beams for FCC. Concerning beam-related machine protection of the whole accelerator chain, it is critical to assess the consequences of beam impact on various accelerator components in the cases of controlled and uncontrolled beam losses. In this paper, we study the energy deposition of protons in solid copper and graphite targets, since the two materials are widely used in magnets, beam screens, collimators, and beam absorbers. Nominal injection and extraction energies in the hadron accelerator complex at CERN were selected in the range of 50 MeV–50 TeV. Three beam sizes were studied for each energy, corresponding to typical values ...

The edge transient-current technique (E-TCT) with high energy hadron beam

Energy Technology Data Exchange (ETDEWEB)

Gorišek, Andrej; Cindro, Vladimir; Kramberger, Gregor; Mandić, Igor [J. Stefan Institute, Ljubljana (Slovenia); Mikuž, Marko [J. Stefan Institute, Ljubljana (Slovenia); University of Ljubljana (Slovenia); Muškinja, Miha; Zavrtanik, Marko [J. Stefan Institute, Ljubljana (Slovenia)

2016-09-21

We propose a novel way to investigate the properties of silicon and CVD diamond detectors for High Energy Physics experiments complementary to the already well-established E-TCT technique using laser beam. In the proposed setup the beam of high energy hadrons (MIPs) is used instead of laser beam. MIPs incident on the detector in the direction parallel to the readout electrode plane and perpendicular to the edge of the detector. Such experiment could prove very useful to study CVD diamond detectors that are almost inaccessible for the E-TCT measurements with laser due to large band-gap as well as to verify and complement the E-TCT measurements of silicon. The method proposed is being tested at CERN in a beam of 120 GeV hadrons using a reference telescope with track resolution at the DUT of few μm. The preliminary results of the measurements are presented.

A technique for measuring an electron beam close-quote s longitudinal phase space with sub-picosecond resolution

International Nuclear Information System (INIS)

Crosson, E.R.; Berryman, K.W.; Richman, B.A.; Smith, T.I.; Swent, R.L.

1996-01-01

We have developed a technique for measuring the longitudinal phase space distribution of the Stanford Superconducting Accelerator close-quote s (SCA) electron beam which involves applying tomographic techniques to energy spectra taken as a function of the relative phase between the beam and the accelerating field, and optionally, as a function of the strength of a variable dispersion section in the system. The temporal profile of the beam obtained by projecting the inferred distribution onto the time axis is compared with that obtained from interferometric transition radiation measurements. copyright 1996 American Institute of Physics

Optical fiber sensors fabricated by the focused ion beam technique

DEFF Research Database (Denmark)

Yuan, Scott Wu; Wang, Fei; Bang, Ole

2012-01-01

crystal fiber (PCF). Using this technique we fabricate a highly compact fiber-optic Fabry-Pérot (FP) refractive index sensor near the tip of fiber taper, and a highly sensitive in-line temperature sensor in PCF. We also demonstrate the potential of using FIB to selectively fill functional fluid......Focused ion beam (FIB) is a highly versatile technique which helps to enable next generation of lab-on-fiber sensor technologies. In this paper, we demonstrate the use application of FIB to precisely mill the fiber taper and end facet of both conventional single mode fiber (SMF) and photonic...

Ion beam induced luminescence characterisation of CVD diamond films

Energy Technology Data Exchange (ETDEWEB)

Bettiol, A.A.; Gonon, P.; Jamieson, D.N. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

1996-12-31

The characterisation of the band structure properties of materials and devices by ion microprobe techniques has been made possible at the Melbourne MeV ion microprobe facility with the development of Ion Beam Induced Luminescence (IBIL). A number of diamond films grown by Microwave Plasma Chemical Vapour Deposition (MPCVD) on silicon substrates are analysed. A preliminary study of the luminescence properties of these samples has revealed information not previously obtainable via traditional microprobe techniques. The optical effects of incorporating dopants during the deposition process is determined using IBIL. The presence of trace element impurities introduced during growth is examined by Particle Induced X-ray Emission (PIXE), and a measurement of the film thickness is made using Rutherford Backscattering Spectrometry (RBS). 7 refs., 2 figs.

Ion beam induced luminescence characterisation of CVD diamond films

Energy Technology Data Exchange (ETDEWEB)

Bettiol, A A; Gonon, P; Jamieson, D N [Melbourne Univ., Parkville, VIC (Australia). School of Physics

1997-12-31

The characterisation of the band structure properties of materials and devices by ion microprobe techniques has been made possible at the Melbourne MeV ion microprobe facility with the development of Ion Beam Induced Luminescence (IBIL). A number of diamond films grown by Microwave Plasma Chemical Vapour Deposition (MPCVD) on silicon substrates are analysed. A preliminary study of the luminescence properties of these samples has revealed information not previously obtainable via traditional microprobe techniques. The optical effects of incorporating dopants during the deposition process is determined using IBIL. The presence of trace element impurities introduced during growth is examined by Particle Induced X-ray Emission (PIXE), and a measurement of the film thickness is made using Rutherford Backscattering Spectrometry (RBS). 7 refs., 2 figs.

Effect of nitrogen environment on NdFeB thin films grown by radio frequency plasma beam assisted pulsed laser deposition

International Nuclear Information System (INIS)

Constantinescu, C.; Patroi, E.; Codescu, M.; Dinescu, M.

2013-01-01

Highlights: ► NdFeB thin films grown by PLD, in vacuum and in nitrogen, are presented. ► Nitrogen inclusion in thin film structures is related to improved coercitivity. ► Magnetical, optical and morphological properties of the thin films are discussed. - Abstract: NdFeB is a very attractive material for applications in electrical engineering and in electronics, for high-tech devices where high coercive field and high remanence are needed. In this paper we demonstrate that the deposition of nitrogen doped NdFeB thin films by pulsed laser deposition, in the presence of a nitrogen radiofrequency plasma beam, exhibit improved magnetic properties and surface morphology, when compared to vacuum deposited NdFeB layers. A Nd:YAG pulsed laser (3ω and 4ω) was focused on a NdFeB target, in vacuum, or in the presence of a nitrogen plasma beam. Substrate temperature (RT-850 °C), nitrogen gas pressure, and radiofrequency power (75–150 W), were particularly varied. The thin films were investigated by means of X-ray diffraction, atomic force microscopy, scanning electron microscopy, spectroscopic-ellipsometry, and vibrating sample magnetometry.

Effect of nitrogen environment on NdFeB thin films grown by radio frequency plasma beam assisted pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Constantinescu, C., E-mail: catalin.constantinescu@inflpr.ro [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor bd., Magurele, RO-077125, Bucharest (Romania); Patroi, E.; Codescu, M. [National Institute for Research and Development in Electrical Engineering - Advanced Research, 313 Spl. Unirii, Sector 3, RO-030138, Bucharest (Romania); Dinescu, M. [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor bd., Magurele, RO-077125, Bucharest (Romania)

2013-03-01

Highlights: Black-Right-Pointing-Pointer NdFeB thin films grown by PLD, in vacuum and in nitrogen, are presented. Black-Right-Pointing-Pointer Nitrogen inclusion in thin film structures is related to improved coercitivity. Black-Right-Pointing-Pointer Magnetical, optical and morphological properties of the thin films are discussed. - Abstract: NdFeB is a very attractive material for applications in electrical engineering and in electronics, for high-tech devices where high coercive field and high remanence are needed. In this paper we demonstrate that the deposition of nitrogen doped NdFeB thin films by pulsed laser deposition, in the presence of a nitrogen radiofrequency plasma beam, exhibit improved magnetic properties and surface morphology, when compared to vacuum deposited NdFeB layers. A Nd:YAG pulsed laser (3{omega} and 4{omega}) was focused on a NdFeB target, in vacuum, or in the presence of a nitrogen plasma beam. Substrate temperature (RT-850 Degree-Sign C), nitrogen gas pressure, and radiofrequency power (75-150 W), were particularly varied. The thin films were investigated by means of X-ray diffraction, atomic force microscopy, scanning electron microscopy, spectroscopic-ellipsometry, and vibrating sample magnetometry.

High-throughput shadow mask printing of passive electrical components on paper by supersonic cluster beam deposition

Energy Technology Data Exchange (ETDEWEB)

Caruso, Francesco; Bellacicca, Andrea; Milani, Paolo, E-mail: pmilani@mi.infn.it [CIMaINa and Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy)

2016-04-18

We report the rapid prototyping of passive electrical components (resistors and capacitors) on plain paper by an additive and parallel technology consisting of supersonic cluster beam deposition (SCBD) coupled with shadow mask printing. Cluster-assembled films have a growth mechanism substantially different from that of atom-assembled ones providing the possibility of a fine tuning of their electrical conduction properties around the percolative conduction threshold. Exploiting the precise control on cluster beam intensity and shape typical of SCBD, we produced, in a one-step process, batches of resistors with resistance values spanning a range of two orders of magnitude. Parallel plate capacitors with paper as the dielectric medium were also produced with capacitance in the range of tens of picofarads. Compared to standard deposition technologies, SCBD allows for a very efficient use of raw materials and the rapid production of components with different shape and dimensions while controlling independently the electrical characteristics. Discrete electrical components produced by SCBD are very robust against deformation and bending, and they can be easily assembled to build circuits with desired characteristics. The availability of large batches of these components enables the rapid and cheap prototyping and integration of electrical components on paper as building blocks of more complex systems.

Tailoring properties of lossy-mode resonance optical fiber sensors with atomic layer deposition technique

Science.gov (United States)

Kosiel, Kamil; Koba, Marcin; Masiewicz, Marcin; Śmietana, Mateusz

2018-06-01

The paper shows application of atomic layer deposition (ALD) technique as a tool for tailoring sensorial properties of lossy-mode-resonance (LMR)-based optical fiber sensors. Hafnium dioxide (HfO2), zirconium dioxide (ZrO2), and tantalum oxide (TaxOy), as high-refractive-index dielectrics that are particularly convenient for LMR-sensor fabrication, were deposited by low-temperature (100 °C) ALD ensuring safe conditions for thermally vulnerable fibers. Applicability of HfO2 and ZrO2 overlays, deposited with ALD-related atomic level thickness accuracy for fabrication of LMR-sensors with controlled sensorial properties was presented. Additionally, for the first time according to our best knowledge, the double-layer overlay composed of two different materials - silicon nitride (SixNy) and TaxOy - is presented for the LMR fiber sensors. The thin films of such overlay were deposited by two different techniques - PECVD (the SixNy) and ALD (the TaxOy). Such approach ensures fast overlay fabrication and at the same time facility for resonant wavelength tuning, yielding devices with satisfactory sensorial properties.

Tracing the plasma interactions for pulsed reactive crossed-beam laser ablation

Energy Technology Data Exchange (ETDEWEB)

Chen, Jikun; Stender, Dieter; Pichler, Markus; Pergolesi, Daniele; Schneider, Christof W.; Wokaun, Alexander; Lippert, Thomas, E-mail: thomas.lippert@psi.ch [General Energy Research Department, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Döbeli, Max [Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland)

2015-10-28

Pulsed reactive crossed-beam laser ablation is an effective technique to govern the chemical activity of plasma species and background molecules during pulsed laser deposition. Instead of using a constant background pressure, a gas pulse with a reactive gas, synchronized with the laser beam, is injected into vacuum or a low background pressure near the ablated area of the target. It intercepts the initially generated plasma plume, thereby enhancing the physicochemical interactions between the gaseous environment and the plasma species. For this study, kinetic energy resolved mass-spectrometry and time-resolved plasma imaging were used to study the physicochemical processes occurring during the reactive crossed beam laser ablation of a partially {sup 18}O substituted La{sub 0.6}Sr{sub 0.4}MnO{sub 3} target using oxygen as gas pulse. The characteristics of the ablated plasma are compared with those observed during pulsed laser deposition in different oxygen background pressures.

Neutron Spectroscopy for pulsed beams with frame overlap using a double time-of-flight technique

Science.gov (United States)

Harrig, K. P.; Goldblum, B. L.; Brown, J. A.; Bleuel, D. L.; Bernstein, L. A.; Bevins, J.; Harasty, M.; Laplace, T. A.; Matthews, E. F.

2018-01-01

A new double time-of-flight (dTOF) neutron spectroscopy technique has been developed for pulsed broad spectrum sources with a duty cycle that results in frame overlap, where fast neutrons from a given pulse overtake slower neutrons from previous pulses. Using a tunable beam at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory, neutrons were produced via thick-target breakup of 16 MeV deuterons on a beryllium target in the cyclotron vault. The breakup spectral shape was deduced from a dTOF measurement using an array of EJ-309 organic liquid scintillators. Simulation of the neutron detection efficiency of the scintillator array was performed using both GEANT4 and MCNP6. The efficiency-corrected spectral shape was normalized using a foil activation technique to obtain the energy-dependent flux of the neutron beam at zero degrees with respect to the incoming deuteron beam. The dTOF neutron spectrum was compared to spectra obtained using HEPROW and GRAVEL pulse height spectrum unfolding techniques. While the unfolding and dTOF results exhibit some discrepancies in shape, the integrated flux values agree within two standard deviations. This method obviates neutron time-of-flight spectroscopy challenges posed by pulsed beams with frame overlap and opens new opportunities for pulsed white neutron source facilities.

Geometry modeling of single track cladding deposited by high power diode laser with rectangular beam spot

Science.gov (United States)

Liu, Huaming; Qin, Xunpeng; Huang, Song; Hu, Zeqi; Ni, Mao

2018-01-01

This paper presents an investigation on the relationship between the process parameters and geometrical characteristics of the sectional profile for the single track cladding (STC) deposited by High Power Diode Laser (HPDL) with rectangle beam spot (RBS). To obtain the geometry parameters, namely cladding width Wc and height Hc of the sectional profile, a full factorial design (FFD) of experiment was used to conduct the experiments with a total of 27. The pre-placed powder technique has been employed during laser cladding. The influence of the process parameters including laser power, powder thickness and scanning speed on the Wc and Hc was analyzed in detail. A nonlinear fitting model was used to fit the relationship between the process parameters and geometry parameters. And a circular arc was adopted to describe the geometry profile of the cross-section of STC. The above models were confirmed by all the experiments. The results indicated that the geometrical characteristics of the sectional profile of STC can be described as the circular arc, and the other geometry parameters of the sectional profile can be calculated only using Wc and Hc. Meanwhile, the Wc and Hc can be predicted through the process parameters.

Reducing beam shaper alignment complexity: diagnostic techniques for alignment and tuning

Science.gov (United States)

Lizotte, Todd E.

2011-10-01

Safe and efficient optical alignment is a critical requirement for industrial laser systems used in a high volume manufacturing environment. Of specific interest is the development of techniques to align beam shaping optics within a beam line; having the ability to instantly verify by a qualitative means that each element is in its proper position as the beam shaper module is being aligned. There is a need to reduce these types of alignment techniques down to a level where even a newbie to optical alignment will be able to complete the task. Couple this alignment need with the fact that most laser system manufacturers ship their products worldwide and the introduction of a new set of variables including cultural and language barriers, makes this a top priority for manufacturers. Tools and methodologies for alignment of complex optical systems need to be able to cross these barriers to ensure the highest degree of up time and reduce the cost of maintenance on the production floor. Customers worldwide, who purchase production laser equipment, understand that the majority of costs to a manufacturing facility is spent on system maintenance and is typically the largest single controllable expenditure in a production plant. This desire to reduce costs is driving the trend these days towards predictive and proactive, not reactive maintenance of laser based optical beam delivery systems [10]. With proper diagnostic tools, laser system developers can develop proactive approaches to reduce system down time, safe guard operational performance and reduce premature or catastrophic optics failures. Obviously analytical data will provide quantifiable performance standards which are more precise than qualitative standards, but each have a role in determining overall optical system performance [10]. This paper will discuss the use of film and fluorescent mirror devices as diagnostic tools for beam shaper module alignment off line or in-situ. The paper will also provide an overview

New approaches for investigating paintings by ion beam techniques

International Nuclear Information System (INIS)

Beck, L.; Viguerie, L. de; Walter, Ph.; Pichon, L.; Gutierrez, P.C.; Salomon, J.; Menu, M.; Sorieul, S.

2010-01-01

Up to now, among the IBA techniques, only PIXE has been used for analyzing paintings. However, quantitative PIXE analysis is sometimes difficult to interpret due to the layered structure, the presence of varnish and organic binder and, in some cases, discoloration of the pigments has been observed due to the interaction of the ion beam with the compounds. In order to improve the characterization of paintings, we propose some alternative experimental procedures. First of all, backscattering spectrometry (BS) and PIXE are simultaneously combined in order to collect complementary information such as layer thickness and organic compound quantification. The simultaneous PIXE and BS experiments also have the advantage of being able to analyze the same area in one experiment. This combination, implemented with an external beam, was directly applied on paintings and on painting cross-sections for the study of Italian Renaissance masterpieces. We have obtained valuable results not only on the pigment itself but also, for the first time, on the binder to pigment proportion which is not well documented in the ancient recipes. Moreover, in order to restrain beam damages due to the ion stopping power, we propose to analyze very thin painting cross-sections by a combination of PIXE-RBS and Scanning Transmission Ion Microscopy (STIM).

New approaches for investigating paintings by ion beam techniques

Science.gov (United States)

Beck, L.; de Viguerie, L.; Walter, Ph.; Pichon, L.; Gutiérrez, P. C.; Salomon, J.; Menu, M.; Sorieul, S.

2010-06-01

Up to now, among the IBA techniques, only PIXE has been used for analyzing paintings. However, quantitative PIXE analysis is sometimes difficult to interpret due to the layered structure, the presence of varnish and organic binder and, in some cases, discoloration of the pigments has been observed due to the interaction of the ion beam with the compounds. In order to improve the characterization of paintings, we propose some alternative experimental procedures. First of all, backscattering spectrometry (BS) and PIXE are simultaneously combined in order to collect complementary information such as layer thickness and organic compound quantification. The simultaneous PIXE and BS experiments also have the advantage of being able to analyze the same area in one experiment. This combination, implemented with an external beam, was directly applied on paintings and on painting cross-sections for the study of Italian Renaissance masterpieces. We have obtained valuable results not only on the pigment itself but also, for the first time, on the binder to pigment proportion which is not well documented in the ancient recipes. Moreover, in order to restrain beam damages due to the ion stopping power, we propose to analyze very thin painting cross-sections by a combination of PIXE-RBS and Scanning Transmission Ion Microscopy (STIM).

New approaches for investigating paintings by ion beam techniques

Energy Technology Data Exchange (ETDEWEB)

Beck, L., E-mail: Lucile.beck@cea.f [Centre de Recherche et de Restauration des Musees de France (C2RMF), CNRS-UMR 171, Palais du Louvre - Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Viguerie, L. de; Walter, Ph.; Pichon, L. [Centre de Recherche et de Restauration des Musees de France (C2RMF), CNRS-UMR 171, Palais du Louvre - Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Gutierrez, P.C. [Centro de Micro-Analisis de Materiales (CMAM), Universidad Autonoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Salomon, J.; Menu, M. [Centre de Recherche et de Restauration des Musees de France (C2RMF), CNRS-UMR 171, Palais du Louvre - Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Sorieul, S. [Centre d' Etudes Nucleaires de Bordeaux-Gradignan, IN2P3, UMR 5797, Universite de Bordeaux 1, Chemin du Solarium BP120, 33175 Gradignan Cedex (France)

2010-06-15

Up to now, among the IBA techniques, only PIXE has been used for analyzing paintings. However, quantitative PIXE analysis is sometimes difficult to interpret due to the layered structure, the presence of varnish and organic binder and, in some cases, discoloration of the pigments has been observed due to the interaction of the ion beam with the compounds. In order to improve the characterization of paintings, we propose some alternative experimental procedures. First of all, backscattering spectrometry (BS) and PIXE are simultaneously combined in order to collect complementary information such as layer thickness and organic compound quantification. The simultaneous PIXE and BS experiments also have the advantage of being able to analyze the same area in one experiment. This combination, implemented with an external beam, was directly applied on paintings and on painting cross-sections for the study of Italian Renaissance masterpieces. We have obtained valuable results not only on the pigment itself but also, for the first time, on the binder to pigment proportion which is not well documented in the ancient recipes. Moreover, in order to restrain beam damages due to the ion stopping power, we propose to analyze very thin painting cross-sections by a combination of PIXE-RBS and Scanning Transmission Ion Microscopy (STIM).

Study of nanocluster-assembled ZnO thin films by nanocluster-beam deposition

Energy Technology Data Exchange (ETDEWEB)

Zhao, Zhiwei; Lei, Wei; Zhang, Xiaobing [School of Electronic Science and Engieering, Southeast University, Nanjing (China); Tay, Beng Kang [School of Electronical and Electronic Engineering, Nanyang Technological University, Nanyang (Singapore)

2012-01-15

Nanocluster-assembled ZnO thin films were obtained by nanocluster-beam deposition, in which nanoclusters were produced by a magnetron sputtering gas aggregation source. Two kinds of ZnO thin films were obtained using this method with the one grown under the on-line heating temperature of 700 C, and the other grown without on-line heating. Film microstructure and optical properties are investigated by various diagnostic techniques. It was found that both of film microstructure of ZnO thin films keep wurtzite structure as that of ZnO bulk materials. The averaged particle size for the film grown without on-line heating is around 6 nm, which is a little lower than that grown with the on-line heating. It was also found that as increasing the wavelength, both of the absorbance spectra for the films decrease sharply near ultra-visible to extend slowly to the visible and infrared wavelength range. For the film grown without on-line heating, the bandgap energy was estimated to 3.77 eV, while for the film grown with on-line heating, the bandgap energy was redshift to 3.71 eV. Similar behavior was also found for PL spectra analysis, where PL spectrum exhibited a peak centered at 3.31 eV without on-line heating, while it redshift to 3.20 eV with on-line heating. The mechanisms behind these behaviors were presented in this article. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Environmental sensing with optical fiber sensors processed with focused ion beam and atomic layer deposition

Science.gov (United States)

Flores, Raquel; Janeiro, Ricardo; Dahlem, Marcus; Viegas, Jaime

2015-03-01

We report an optical fiber chemical sensor based on a focused ion beam processed optical fiber. The demonstrated sensor is based on a cavity formed onto a standard 1550 nm single-mode fiber by either chemical etching, focused ion beam milling (FIB) or femtosecond laser ablation, on which side channels are drilled by either ion beam milling or femtosecond laser irradiation. The encapsulation of the cavity is achieved by optimized fusion splicing onto a standard single or multimode fiber. The empty cavity can be used as semi-curved Fabry-Pérot resonator for gas or liquid sensing. Increased reflectivity of the formed cavity mirrors can be achieved with atomic layer deposition (ALD) of alternating metal oxides. For chemical selective optical sensors, we demonstrate the same FIB-formed cavity concept, but filled with different materials, such as polydimethylsiloxane (PDMS), poly(methyl methacrylate) (PMMA) which show selective swelling when immersed in different solvents. Finally, a reducing agent sensor based on a FIB formed cavity partially sealed by fusion splicing and coated with a thin ZnO layer by ALD is presented and the results discussed. Sensor interrogation is achieved with spectral or multi-channel intensity measurements.

Evaluation of Temporal Diagnostic Techniques for Two-Bunch Facet Beam

Energy Technology Data Exchange (ETDEWEB)

Litos, M.D.; Bionta, M.R.; Dolgashev, V.A.; England, R.J.; Fritz, D.; Gilevich, S.; Hering, Ph.; Hogan, M.J.; /SLAC

2011-08-19

Three temporal diagnostic techniques are considered for use in the FACET facility at SLAC, which will incorporate a unique two-bunch beam for plasma wakefield acceleration experiments. The results of these experiments will depend strongly on the the inter-bunch spacing as well as the longitudinal profiles of the two bunches. A reliable, singleshot, high resolution measurement of the beam's temporal profile is necessary to fully quantify the physical mechanisms underlying the beam driven plasma wakefield acceleration. In this study we show that a transverse deflecting cavity is the diagnostic which best meets our criteria. Based on our laboratory testing, numerical calculations, and simulations of the three single-shot temporal diagnostic devices, the X-band TCAV system is the best candidate for resolving FACET's two-bunch beam, with an estimated resolution of 7 {micro}m. Both the S-band TCAV system and the EO system could resolve the peak-to-peak separation of the two bunches in the FACET beam with estimated resolutions of 25 {micro}m and 30 {micro}m, respectively, but would be unable to resolve the temporal profiles of the individual bunches themselves. Because the TCAV signal is more easily interpreted and because the reliability of the EO system is less well known, however, the S-band TCAV system would be the next preferred option after the X-band TCAV system. The Fesca-200 streak camera, though simple, compact, and reliable, is unable to achieve a resolution that would be of use to FACET.

Spatial dose and microdose distribution in tissues. Ionization, nuclear reactions, multiple scattering simulation of beam transport

International Nuclear Information System (INIS)

Jacquot, C.

1976-01-01

Computer simulation and nuclear emulsion and gelatin techniques enabled to give the total elastic and inelastic cross sections and to forecast the spatial microdose distributions in cells, nuclei and molecules. For this purpose, the transport of a beam into tissues having a given composition is calculated, the nuclear reactions are generated and the energy depositions in standard planes perpendicular to the beam are recorded

Molecular beam and pulsed laser deposition of ZnS:Cr for intermediate band solar cells

OpenAIRE

Nematollahi, Mohammadreza; Yang, Xiaodong; Aas, Lars Martin Sandvik; Ghadyani, Zahra; Kildemo, Morten; Gibson, Ursula; Reenaas, Turid Worren

2015-01-01

We have investigated the structural and optical properties of Cr-doped ZnS (ZnS:Cr) thin films (0–7.5 at.% Cr) for use in intermediate band solar cells. The films were grown on Si(100) in molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) equipments. Introducing Cr into ZnS resulted in Cr related subbandgap absorption, but also reduced the grain size. The sub-bandgap absorption increased with increasing Cr content, and with increasing growth temperature, but did not depend on the ...

Comparative study of CdTe sources used for deposition of CdTe thin films by close spaced sublimation technique

Directory of Open Access Journals (Sweden)

Wagner Anacleto Pinheiro

2006-03-01

Full Text Available Unlike other thin film deposition techniques, close spaced sublimation (CSS requires a short source-substrate distance. The kind of source used in this technique strongly affects the control of the deposition parameters, especially the deposition rate. When depositing CdTe thin films by CSS, the most common CdTe sources are: single-crystal or polycrystalline wafers, powders, pellets or pieces, a thick CdTe film deposited onto glass or molybdenum substrate (CdTe source-plate and a sintered CdTe powder. In this work, CdTe thin films were deposited by CSS technique from different CdTe sources: particles, powder, compact powder, a paste made of CdTe and propylene glycol and source-plates (CdTe/Mo and CdTe/glass. The largest deposition rate was achieved when a paste made of CdTe and propylene glycol was used as the source. CdTe source-plates led to lower rates, probably due to the poor heat transmission, caused by the introduction of the plate substrate. The results also showed that compacting the powder the deposition rate increases due to the better thermal contact between powder particles.

Potential ceramics processing applications with high-energy electron beams

International Nuclear Information System (INIS)

Struve, K.W.; Turman, B.N.

1993-01-01

High-energy, high-current electron beams may offer unique features for processing of ceramics that are not available with any other heat source. These include the capability to instantaneously heat to several centimeters in depth, to preferentially deposit energy in dense, high-z materials, to process at atmospheric pressures in air or other gases, to have large control over heating volume and heating rate, and to have efficient energy conversion. At a recent workshop organized by the authors to explore opportunities for electron beam processing of ceramics, several applications were identified for further development. These were ceramic joining, fabrication of ceramic powders, and surface processing of ceramics. It may be possible to join ceramics by either electron-beam brazing or welding. Brazing with refractory metals might also be feasible. The primary concern for brazing is whether the braze material can wet to the ceramic when rapidly heated by an electron beam. Raw ceramic powders, such as silicon nitride and aluminum nitride, which are difficult to produce by conventional techniques, could possibly be produced by vaporizing metals in a nitrogen atmosphere. Experiments need to be done to verify that the vaporized metal can fully react with the nitrogen. By adjusting beam parameters, high-energy beams can be used to remove surface flaws which are often sites of fracture initiation. They can also be used for surface cleaning. The advantage of electron beams rather than ion beams for this application is that the heat deposition can be graded into the material. The authors will discuss the capabilities of beams from existing machines for these applications and discuss planned experiments

Arc-based smoothing of ion beam intensity on targets

International Nuclear Information System (INIS)

Friedman, Alex

2012-01-01

By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy (“heavy-ion fusion”). Here, we consider an approach to such smoothing that is based on rapidly “wobbling” each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

Metal-insulator transition in Pt-C nanowires grown by focused-ion-beam-induced deposition

International Nuclear Information System (INIS)

Fernandez-Pacheco, A.; Ibarra, M. R.; De Teresa, J. M.; Cordoba, R.

2009-01-01

We present a study of the transport properties of Pt-C nanowires created by focused-ion-beam (FIB)-induced deposition. By means of the measurement of the resistance while the deposit is being performed, we observe a progressive decrease in the nanowire resistivity with thickness, changing from 10 8 μΩ cm for thickness ∼20 nm to a lowest saturated value of 700 μΩ cm for thickness >150 nm. Spectroscopy analysis indicates that this dependence on thickness is caused by a gradient in the metal-carbon ratio as the deposit is grown. We have fabricated nanowires in different ranges of resistivity and studied their conduction mechanism as a function of temperature. A metal-insulator transition as a function of the nanowire thickness is observed. The results will be discussed in terms of the Mott-Anderson theory for noncrystalline materials. An exponential decrease in the conductance with the electric field is found for the most resistive samples, a phenomenon understood by the theory of hopping in lightly doped semiconductors under strong electric fields. This work explains the important discrepancies found in the literature for Pt-C nanostructures grown by FIB and opens the possibility to tune the transport properties of this material by an appropriate selection of the growth parameters.

Accuracy of image-guided radiotherapy of prostate cancer based on the BeamCath urethral catheter technique

DEFF Research Database (Denmark)

Poulsen, Per Rugaard; Fokdal, Lars; Petersen, Jørgen B.B.

2007-01-01

BACKGROUND AND PURPOSE: To examine the accuracy of the BeamCath urethral catheter technique for prostate localization during radiotherapy. MATERIALS AND METHODS: Sixty-four patients were CT scanned twice with the BeamCath catheter, and once without the catheter. The catheter contains radiopaque...

Novel geochemical techniques integrated in exploration for uranium deposits at depth

International Nuclear Information System (INIS)

Kyser, K.

2014-01-01

Mineral deposits are in fact geochemical anomalies, and as such their detection and assessment of their impact on the environment should be facilitated using geochemical techniques. Although geochemistry has been used directly in the discovery of uranium deposits and more indirectly in shaping deposit models, the novel applications of geochemistry and integration with other data can be more effective in formulating exploration and remediation strategies. Recent research on the use of geochemistry in detecting uranium deposits at depth include: (1) more effective integration of geochemical with geophysical data to refine targets, (2) revealing element distributions in and around deposits to adequately assess the total chemical environment associated with the deposit, (3) the use of element tracing using elemental concentrations and isotopic compositions in the near surface environment to detect specific components that have migrated to the surface from uranium deposits at depth, (4) understand the effects of both macro- and micro-environments on element mobility across the geosphere-biosphere interface to enhance exploration using select media for uranium at depth. Geophysical data used in exploration can identify areas of conductors where redox contrasts may host mineralization, structures that act to focus fluids during formation of the deposits and act as conduits for element migration to the surface, and contrasts in geology that are required for the deposits. However, precision of these data is greatly diminished with depth, but geochemical data from drill core or surface media can enhance target identification when integrated with geophysical data. Geochemical orientation surveys over known unconformity-related deposits at depth clearly identify mineralization 900m deep. Drill core near the deposit, clay-size fractions separated from soil horizons and vegetation over and far from the deposit record element migration from the deposit as radiogenic He, Rn and Pb

A Effect discussion of transient electromagnetic sounding technique in paleochannel-type sandstone-hosted uranium deposit

International Nuclear Information System (INIS)

Yang Jianchun; Fang Genxian; Yang Yaxin

2003-01-01

On the base of the application of transient electromagnetic technique of paleochannel-type sandstone-hosted uranium deposits in Tengchong region of Yunan Province, this paper analyses the detect example. It discusses the theory foundation of TEM, fieldwork means, data processing and interpret. By contrast with routine electricity farad, the transient electromagnetic technique have the special merit and favorable space resolve gender under conditions of intricacy terrain. This means can get good effect in detecting paleochannel-type sandstone-hosted uranium deposits space position. It is a good reference for other prospecting and exploration work

Modification of PMMA/graphite nanocomposites through ion beam technique

Science.gov (United States)

Singhal, Prachi; Rattan, Sunita; Avasthi, Devesh Kumar; Tripathi, Ambuj

2013-08-01

Swift heavy ion (SHI) irradiation is a special technique for inducing physical and chemical modifications in bulk materials. In the present work, the SHI hs been used to prepare nanocomposites with homogeneously dispersed nanoparticles. The nanographite was synthesized from graphite using the intercalation-exfoliation method. PMMA Poly(methyl methacrylate)/graphite nanocomposites have been synthesized by in situ polymerization. The prepared PMMA/graphite nanocomposite films were irradiated with SHI irradiation (Ni ion beam, 80 MeV and C ion beam, 50 MeV) at a fluence of 1×1010 to 3×1012 ions/cm2. The nanocomposite films were characterized by scanning electron microscope (SEM) and were evaluated for their electrical and sensor properties. After irradiation, significant changes in surface morphology of nanocomposites were observed as evident from the SEM images, which show the presence of well-distributed nanographite platelets. The irradiated nanocomposites exhibit better electrical and sensor properties for the detection of nitroaromatics with marked improvement in sensitivity as compared with unirradiated nanocomposites.

Techniques for freeing deposited canisters. Final report

International Nuclear Information System (INIS)

Kalbantner, P.; Sjoeblom, R.

2000-06-01

Four different techniques for removal of the bentonite buffer around a deposited canister have been identified, studied and evaluated: mechanical, hydrodynamical, thermal, and electrical techniques. Different techniques to determine the position of the canister in the buffer have also been studied: mechanical, electromagnetic, thermal and acoustic techniques. The mechanical techniques studied are full-face boring, milling and core-drilling. It is expected that the bentonite can be machined relatively easily. It is assessed that cooling by means of flushing water over the outer surfaces of the tools is not feasible in view of the tendency of bentonite to form a gel. The mechanical techniques are characterized by the potential of damaging the canister, a high degree of complexity, and high requirements of energy/power input. The generated byproduct is solid and cannot be removed by means of flushing. Removal is assessed to be simplest in conjunction with full-face boring and most difficult when coredrilling is applied. The hydrodynamical techniques comprise high-pressure hydrodynamic techniques, where pressures above and below 100 bar, and low pressure hydrodynamical techniques (< 10 bar) are separated. At pressures above 100 bar, a water jet with a diameter of approximately a millimetre cuts through the material. If desired, sand can be added to the jet. At pressures below 100 bar the jet has a diameter of one or a few centimetres. The liquid contains a few percent of salt, which is essential for the efficiency of the process. The flushing is important not only because it removes the modified bentonite but also because it frees previously unaffected bentonite and thereby makes it accessible to chemical modification. All of the hydrodynamical techniques are applicable for freeing the end surface as well as the mantle surface. The degree of complexity and the requirement on energy/power decrease with a decrease in pressure. A significant potential for damaging the

Influence of ion/atom arrival ratio on structure and optical properties of AlN films by ion beam assisted deposition

Energy Technology Data Exchange (ETDEWEB)

Meng, Jian-ping [Department of Energy Material and Technology, General Research Institute for Nonferrous Metals, Beijing 100088 (China); School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China); Fu, Zhi-qiang, E-mail: fuzq@cugb.edu.cn [School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China); Liu, Xiao-peng [Department of Energy Material and Technology, General Research Institute for Nonferrous Metals, Beijing 100088 (China); Yue, Wen; Wang, Cheng-biao [School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China)

2014-10-30

Highlights: • AlN films were fabricated by dual ion beam sputtering. • Chemical bond status and phase composition of the films were studied by XPS and XRD. • Optical constants were measured by spectroscopic ellipsometry. • Influence of ion/atom arrival ratio on the films was studied. - Abstract: In order to improve the optical properties of AlN films, the influence of the ion/atom arrival ratio on the structure and optical characteristics of AlN films deposited by dual ion beam sputtering was studied by using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, spectroscopic ellipsometry and UV–vis spectroscopy. The films prepared at the ion/atom arrival ratio of 1.4 are amorphous while the crystalline quality is improved with the increase of the ion/atom arrival ratio. The films deposited at the ion/atom arrival ratio of no less than 1.8 have an approximately stoichiometric ratio and mainly consist of aluminum nitride with little aluminum oxynitride, while metallic aluminum component appears in the films deposited at the ion/atom arrival ratio of 1.4. When the ion/atom arrival ratio is not less than 1.8, films are smooth, high transmitting and dense. The films prepared with high ion/atom arrival ratio (≥1.8) display the characteristic of a dielectric. The films deposited at the ion/atom arrival ratio of 1.4 are coarse, opaque and show characteristic of cermet.

Probe beam deflection technique as acoustic emission directionality sensor with photoacoustic emission source.

Science.gov (United States)

Barnes, Ronald A; Maswadi, Saher; Glickman, Randolph; Shadaram, Mehdi

2014-01-20

The goal of this paper is to demonstrate the unique capability of measuring the vector or angular information of propagating acoustic waves using an optical sensor. Acoustic waves were generated using photoacoustic interaction and detected by the probe beam deflection technique. Experiments and simulations were performed to study the interaction of acoustic emissions with an optical sensor in a coupling medium. The simulated results predict the probe beam and wavefront interaction and produced simulated signals that are verified by experiment.

Thickness Dependence of Optoelectrical Properties of Mo-Doped In2O3 Films Deposited on Polyethersulfone Substrates by Ion-Beam-Assisted Evaporation

Directory of Open Access Journals (Sweden)

Chin-Chiuan Kuo

2010-01-01

Full Text Available Indium molybdenum oxide (IMO films were deposited onto the polyethersulfone (PES substrates by ion-beam-assisted evaporation (IBAE deposition at low temperature in this study. The effects of film thickness on their optical and electrical properties were investigated. The results show that the deposited IMO films exhibit a preferred orientation of B(222. The electrical resistivity of the deposited film initially reduces then subsequently increases with film thickness. The IMO film with the lowest resistivity of 7.61 × 10−4 ohm-cm has been achieved when the film thickness is 120 nm. It exhibits a satisfactory surface roughness pv of 8.75 nm and an average visible transmittance of 78.7%.

Beams of mass-selected clusters: realization and first experiments

International Nuclear Information System (INIS)

Kamalou, O.

2007-04-01

The main objective of this work concerns the production of beams of mass-selected clusters of metallic and semiconductor materials. Clusters are produced in magnetron sputtering source combined with a gas aggregation chamber, cooled by liquid nitrogen circulation. Downstream of the cluster source, a Wiley-McLaren time-of-flight setup allows to select a given cluster size or a narrow size range. The pulsed mass-selected cluster ion beam is separated from the continuous neutral one by an electrostatic 90-quadrupole deflector. After the deflector, the density of the pulsed beam amounts to about 10 3 particles/cm 3 . Preliminary deposition experiments of mass-selected copper clusters with a deposition energy of about 0.5 eV/atom have ben performed on highly oriented pyrolytic graphite (HOPG) substrates, indicating that copper clusters are evidently mobile on the HOPG-surface until they reach cleavage steps, dislocation lines or other surface defects. In order to lower the cluster mobility on the HOPG-surface, we have first irradiated HOPG samples with slow highly charged ions (high dose) in order to create superficial defects. In a second step we have deposited mass-selected copper clusters on these pre-irradiated samples. The first analysis by AFM (Atomic Force Microscopy) techniques showed that the copper clusters are trapped on the defects produced by the highly charged ions. (author)

A combined molecular dynamics and Monte Carlo simulation of the spatial distribution of energy deposition by proton beams in liquid water

Energy Technology Data Exchange (ETDEWEB)

Garcia-Molina, Rafael [Departamento de Fisica, Centro de Investigacion en Optica y Nanofisica (CIOyN), Universidad de Murcia, E-30100 Murcia (Spain); Abril, Isabel [Departament de Fisica Aplicada, Universitat d' Alacant, E-03080 Alacant (Spain); Heredia-Avalos, Santiago [Departament de Fisica, Enginyeria de Sistemes i Teoria del Senyal, Universitat d' Alacant, E-03080 Alacant (Spain); Kyriakou, Ioanna; Emfietzoglou, Dimitris, E-mail: rgm@um.es [Medical Physics Laboratory, University of Ioannina Medical School, GR-45110 Ioannina (Greece)

2011-10-07

We have evaluated the spatial distribution of energy deposition by proton beams in liquid water using the simulation code SEICS (Simulation of Energetic Ions and Clusters through Solids), which combines molecular dynamics and Monte Carlo techniques and includes the main interaction phenomena between the projectile and the target constituents: (i) the electronic stopping force due to energy loss to target electronic excitations, including fluctuations due to the energy-loss straggling, (ii) the elastic scattering with the target nuclei, with their corresponding energy loss and (iii) the dynamical changes in projectile charge state due to electronic capture and loss processes. An important feature of SEICS is the accurate account of the excitation spectrum of liquid water, based on a consistent solid-state description of its energy-loss-function over the whole energy and momentum space. We analyse how the above-mentioned interactions affect the depth distribution of the energy delivered in liquid water by proton beams with incident energies of the order of several MeV. Our simulations show that the position of the Bragg peak is determined mainly by the stopping power, whereas its width can be attributed to the energy-loss straggling. Multiple elastic scattering processes contribute slightly only at the distal part of the Bragg peak. The charge state of the projectiles only changes when approaching the end of their trajectories, i.e. near the Bragg peak. We have also simulated the proton-beam energy distribution at several depths in the liquid water target, and found that it is determined mainly by the fluctuation in the energy loss of the projectile, evaluated through the energy-loss straggling. We conclude that a proper description of the target excitation spectrum as well as the inclusion of the energy-loss straggling is essential in the calculation of the proton beam depth-dose distribution.

A combined molecular dynamics and Monte Carlo simulation of the spatial distribution of energy deposition by proton beams in liquid water

International Nuclear Information System (INIS)

Garcia-Molina, Rafael; Abril, Isabel; Heredia-Avalos, Santiago; Kyriakou, Ioanna; Emfietzoglou, Dimitris

2011-01-01

We have evaluated the spatial distribution of energy deposition by proton beams in liquid water using the simulation code SEICS (Simulation of Energetic Ions and Clusters through Solids), which combines molecular dynamics and Monte Carlo techniques and includes the main interaction phenomena between the projectile and the target constituents: (i) the electronic stopping force due to energy loss to target electronic excitations, including fluctuations due to the energy-loss straggling, (ii) the elastic scattering with the target nuclei, with their corresponding energy loss and (iii) the dynamical changes in projectile charge state due to electronic capture and loss processes. An important feature of SEICS is the accurate account of the excitation spectrum of liquid water, based on a consistent solid-state description of its energy-loss-function over the whole energy and momentum space. We analyse how the above-mentioned interactions affect the depth distribution of the energy delivered in liquid water by proton beams with incident energies of the order of several MeV. Our simulations show that the position of the Bragg peak is determined mainly by the stopping power, whereas its width can be attributed to the energy-loss straggling. Multiple elastic scattering processes contribute slightly only at the distal part of the Bragg peak. The charge state of the projectiles only changes when approaching the end of their trajectories, i.e. near the Bragg peak. We have also simulated the proton-beam energy distribution at several depths in the liquid water target, and found that it is determined mainly by the fluctuation in the energy loss of the projectile, evaluated through the energy-loss straggling. We conclude that a proper description of the target excitation spectrum as well as the inclusion of the energy-loss straggling is essential in the calculation of the proton beam depth-dose distribution.

Ion-beam technologies

Energy Technology Data Exchange (ETDEWEB)

Fenske, G.R. [Argonne National Lab., IL (United States)

1993-01-01

This compilation of figures and diagrams reviews processes for depositing diamond/diamond-like carbon films. Processes addressed are chemical vapor deposition (HFCVD, PACVD, etc.), plasma vapor deposition (plasma sputtering, ion beam sputtering, evaporation, etc.), low-energy ion implantation, and hybrid processes (biased sputtering, IBAD, biased HFCVD, etc.). The tribological performance of coatings produced by different means is discussed.

14th International Workshop on Slow Positron Beam Techniques and Applications

International Nuclear Information System (INIS)

2017-01-01

These proceedings arose from the 14th International Workshop on Slow Positron Beam Techniques (SLOPOS14), which was held at Kunibiki Messe, Matsue, Shimane prefecture, Japan, from the 22nd—27th May 2016. Meetings in the SLOPOS series are held every three years. The SLOPOS workshop series has traditionally been devoted to investigations on the production of positron and positronium beams, their fundamental physics and chemistry, and their applications to materials such as metals, semiconductors and soft matter. During the workshop numerous applications using positron and positronium beams were also presented, clearly demonstrating the usefulness of such beams to the determination of surface structure, defect characterization as well as to fundamental scientific studies. For SLOPOS14 the main subjects of the workshop included the following: • Positron transport and beam technology • Pulsed positron beams and positron traps • Defect profiling in bulk and layered structures • Nano structures, porous materials and thin films • Surface and interface analysis • Positronium formation, emission and beams • Positron and positronium interactions with atoms and molecules • Many positrons and anti-hydrogen • Improvement of experimental techniques 106 delegates from 14 countries participated in the SLOPOS14, including 31 student delegates, which was a most encouraging sign for the future. The scientific program comprised 5 plenary talks, 22 invited talks, 32 contributed talks and 46 posters presented during two poster sessions. Student prizes were awarded for the best presented scientific contributions by 4 students from University of College London, Universität der Bundeswehr München and The University of Tokyo. On a sad note, delegates paid tribute to the contributions of our recently deceased colleagues, Prof. A. Seeger, Prof. R.N. West, Prof. T.C. Griffith, and Prof. Z. Tang. Memorial talks were given and a one minute silence was observed before the

External-beam PIXE characterization of volcanic material used in ancient Roman mortars

International Nuclear Information System (INIS)

Sonck-Koota, P.; Lindroos, A.; Lill, J.-O.; Rajander, J.; Viitanen, E.-M.; Marra, F.; Pehkonen, M.H.; Suksi, J.; Heselius, S.-J.

2008-01-01

Volcanic deposits from two volcanic districts, Monti Sabatini (MSVD) and Colli Albani (CAVD), NW and SE of Rome, were analyzed using the particle-induced X-ray emission (PIXE) technique, in order to obtain chemical fingerprints that can be used for provenance studies of filler materials in ancient Roman mortars. The rock samples were mounted on an X-Y stage enabling scanning over the sample surface and irradiated in air with a collimated 3 MeV proton beam. The samples were either analyzed by scanning the beam over a polished surface or they were crushed, ground and homogenized prior to the irradiation. However, scanning over polished sample surfaces avoiding heterogeneities gave quite similar results as scanning over pellet surfaces, especially for the minor and trace elements. This study shows that the deposits of MSVD and CAVD can be distinguished from each other. Several elements or elemental ratios can be used to characterize the districts. Even the individual volcanic deposits of CAVD can be identified

The influence of inhalation technique on Technegas particle deposition and image appearance in normal volunteers

International Nuclear Information System (INIS)

Lloyd, J.J.; James, J.M.; Shields, R.A.; Testa, H.J.

1994-01-01

The aim of this work was to investigate the influence of inhalation technique on Technegas image quality and on fractional particle deposition. This was investigated in six normal volunteers using three different types of breathing pattern. Fractional deposition was determined by analysis of dynamic gamma camera images acquired during Technegas administration. Static lung images were subsequently acquired and assessed independently by three experienced observers. High-quality images were obtained in all cases although slight differences were noted. The images produced using a slow deep inspiration with a breath hold (i.e. the standard method) were of more uniform texture and also had the least gradient in activity from apex to base. The converse was true for a rapid inhalation technique. The average fractional deposition per breath was 55%, but this varied between individuals and with breathing pattern, being most influenced by the total duration of a breath. We conclude that for patient studies the standard inhalation technique is best, although variation to suit individual patients would be acceptable. (orig./MG)

Dosimetric characterization of BeO samples in alpha, beta and X radiation beams using luminescent techniques

International Nuclear Information System (INIS)

Groppo, Daniela Piai

2013-01-01

In the medical field, the ionizing radiation is used both for therapeutic and diagnostic purposes, in a wide range of radiation doses. In order to ensure that the objective is achieved in practice, detailed studies of detectors and devices in different types of radiations beams are necessary. In this work a dosimetric characterization of BeO samples was performed using the techniques of thermoluminescence (TL) and optically stimulated luminescence (OSL) by a comparison of their response for alpha, beta and X radiations and the establishment of an appropriated system for use in monitoring of these radiations beams. The main results are: the high sensitivity to beta radiation for both techniques, good reproducibility of TL and OSL response (coefficients of variation lower than 5%), maximum energy dependence of the X radiation of 28% for the TL technique, and only 7% for the OSL technique, within the studied energy range. The dosimetric characteristics obtained in this work show the possibility of applying BeO samples to dosimetry of alpha, beta and X radiations, considering the studied dose ranges, using the TL and OSL techniques. From the results obtained, the samples of BeO showed their potential use for beam dosimetry in diagnostic radiology and radiotherapy. (author)

Fatigue Life of Titanium Alloys Fabricated by Additive Layer Manufacturing Techniques for Dental Implants

Science.gov (United States)

Chan, Kwai S.; Koike, Marie; Mason, Robert L.; Okabe, Toru

2013-02-01

Additive layer deposition techniques such as electron beam melting (EBM) and laser beam melting (LBM) have been utilized to fabricate rectangular plates of Ti-6Al-4V with extra low interstitial (ELI) contents. The layer-by-layer deposition techniques resulted in plates that have different surface finishes which can impact significantly on the fatigue life by providing potential sites for fatigue cracks to initiate. The fatigue life of Ti-6Al-4V ELI alloys fabricated by EBM and LBM deposition techniques was investigated by three-point testing of rectangular beams of as-fabricated and electro-discharge machined surfaces under stress-controlled conditions at 10 Hz until complete fracture. Fatigue life tests were also performed on rolled plates of Ti-6Al-4V ELI, regular Ti-6Al-4V, and CP Ti as controls. Fatigue surfaces were characterized by scanning electron microscopy to identify the crack initiation site in the various types of specimen surfaces. The fatigue life data were analyzed statistically using both analysis of variance techniques and the Kaplan-Meier survival analysis method with the Gehan-Breslow test. The results indicate that the LBM Ti-6Al-4V ELI material exhibits a longer fatigue life than the EBM counterpart and CP Ti, but a shorter fatigue life compared to rolled Ti-6Al-4V ELI. The difference in the fatigue life behavior may be largely attributed to the presence of rough surface features that act as fatigue crack initiation sites in the EBM material.

Microdosimetry of high LET therapeutic beams

International Nuclear Information System (INIS)

Ito, Akira

1980-01-01

Experimental microdosimetry of high LET therapeutic beams were presented. The cyclotron produced fast neutron beams at IMS, TAMVEC and NRL, a reactor fast neutron at YAYOI, a proctor beam at Harvard and a pion beam at TRIUMF are included. Measurements were performed with a conventional tissue equivalent spherical proportional counter with a logarithmic amplifier which made the recording and analysis quite simple. All the energy deposition spectra were analysed in the conventional manner and anti y F, anti y D as well as anti y D* were calculated. The spectra and their mean lineal energies showed wide variations, depending on the particle type, energy, position in phantom. Fractional contribution of elemental particles ( electron, muon, pion, proton, alpha and so on) to the total dose were analysed. For fast neutron beams, the y spectra stayed almost constant at any depth along the central axis in the phantom. The y spectra of proton beam changed slightly along the depth. On the other side, the y spectra of pion beam change drastically in the phantom between plateau and dose peak region. A novel technique of time-of-flight microdosimetry was employed, which made it possible to separate the fractional contribution of contaminant electrons and muons out of pions. Finally, a map of the radiation quality for all the beams is presented and its significances are discussed. (author)

Vietnam Project For Production Of Radioactive Beam Based On ISOL Technique With The Dalat Reactor

International Nuclear Information System (INIS)

Le Hong Khiem; Phan Viet Cuong; Fadi Ibrahim

2011-01-01

The presence in Vietnam of Dalat nuclear reactor dedicated to fundamental studies is a unique opportunity to produce Radioactive Ion (RI) Beams with the fission of a 235 U induced by the thermal neutrons produced by the reactor. We propose to produce RI beams at the Dalat nuclear reactor using ISOL (Isotope Separation On-Line) technique. This project should be a unique opportunity for Vietnamese nuclear physics community to use its own facilities to produce RI beams for studying nuclear physics at an international level. (author)

A technique for simultaneous detection of individual vortex states of Laguerre-Gaussian beams transmitted through an aqueous suspension of microparticles

Science.gov (United States)

Khonina, S. N.; Karpeev, S. V.; Paranin, V. D.

2018-06-01

A technique for simultaneous detection of individual vortex states of the beams propagating in a randomly inhomogeneous medium is proposed. The developed optical system relies on the correlation method that is invariant to the beam wandering. The intensity distribution formed at the optical system output does not require digital processing. The proposed technique based on a multi-order phase diffractive optical element (DOE) is studied numerically and experimentally. The developed detection technique is used for the analysis of Laguerre-Gaussian vortex beams propagating under conditions of intense absorption, reflection, and scattering in transparent and opaque microparticles in aqueous suspensions. The performed experimental studies confirm the relevance of the vortex phase dependence of a laser beam under conditions of significant absorption, reflection, and scattering of the light.

Hydrogen ratios and profiles in deposited amorphous and polycrystalline films and in metals using nuclear techniques

International Nuclear Information System (INIS)

Benenson, R.E.; Feldman, L.C.; Bagley, B.G.

1980-01-01

Plasma- and chemical vapor deposited films containing hydrogen, Si, B and O, but of unknown thickness and stoichiometry have been assigned concentration ratios through a combination of H-profiling using the 1 H( 15 N,αγ) 12 C(4.43 MeV) reaction and RBS analysis. Relatively intense 15 N ++ beams exceeding the 6.38 MeV resonance energy have been obtained from a 3.75 MeV accelerator with a commercial ion source and terminal analysis. A discussion is given of the method of obtaining film concentration ratios in some representative cases. A search was made for H at the SiO 2 -Si interface. Some preliminary investigations have been made on the H concentration in several metals as supplied: Nb, V, Ta, Al, Ni, OFHC Cu, Ti, Mo and steel and on the effect of acid dips in loading H. Hydrogen in acid-loaded steel migrated under the influence of the probing 15 N beam, but relaxed back when the beam was removed. (orig.)

On the deposition parameters of indium oxide (IO) and tin oxide (TO) by reactive evaporation technique

International Nuclear Information System (INIS)

Hassan, F.; Abdullah, A.H.; Salam, R.

1990-01-01

Thin films of tin oxide (TO) and indium oxide (IO) are prepared by the reactive evaporation technique, where indium or tin sources are evaporated and made to react with oxygen gas injected close to the substrate. In both depositions a substrate temperature of 380 0 C and a chamber pressure of 2x10 -5 mbar are utilized, but however different oxygen flow rates has been maintained. For TO, the deposition rate is found to be constant up to about 55 minutes of deposition time with a deposition rate of about 0.10 A/s, but for longer deposition time the deposition rate increases rapidly up to about 0.30 A/s. The IO displays a higher deposition rate of about 0.80 A/s over a deposition time 30 minutes, beyond which the deposition rate increases gradually

Pure high dose metal ion implantation using the plasma immersion technique

International Nuclear Information System (INIS)

Zhang, T.; Tang, B.Y.; Zeng, Z.M.; Kwok, T.K.; Chu, P.K.; Monteiro, O.R.; Brown, I.G.

1999-01-01

High energy implantation of metal ions can be carried out using conventional ion implantation with a mass-selected ion beam in scanned-spot mode by employing a broad-beam approach such as with a vacuum arc ion source, or by utilizing plasma immersion ion implantation with a metal plasma. For many high dose applications, the use of plasma immersion techniques offers a high-rate process, but the formation of a surface film along with the subsurface implanted layer is sometimes a severe or even fatal detriment. We describe here an operating mode of the metal plasma immersion approach by which pure implantation can be obtained. We have demonstrated the technique by carrying out Ti and Ta implantations at energies of about 80 and 120 keV for Ti and Ta, respectively, and doses on the order of 1x10 17 ions/cm 2 . Our experiments show that virtually pure implantation without simultaneous surface deposition can be accomplished. Using proper synchronization of the metal arc and sample voltage pulse, the applied dose that deposits as a film versus the part that is energetically implanted (the deposition-to-implantation ratio) can be precisely controlled.copyright 1999 American Institute of Physics

X-ray photoelectron spectroscopy investigation of ion beam sputtered indium tin oxide films as a function of oxygen pressure during deposition

International Nuclear Information System (INIS)

Nelson, A.J.; Aharoni, H.

1987-01-01

X-ray photoelectron spectroscopy analysis was performed on ion beam sputter deposited films of indium tin oxide as a function of O 2 partial pressure during deposition. The oxygen partial pressure was varied over the range of 2.5 x 10 -6 --4.0 x 10 -5 Torr. Changes in composition as well as in the deconvoluted In 3d 5 /sub // 2 , Sn 3d 5 /sub // 2 , and O 1s core level spectra were observed and correlated with the variation of the oxygen partial pressure during deposition. Results show that the films become increasingly stoichiometric as P/sub =/ is increased and that the excess oxygen introduced during deposition is bound predominantly to the Sn and has little or no effect on the In--O bonding

Cluster ion beam facilities

International Nuclear Information System (INIS)

Popok, V.N.; Prasalovich, S.V.; Odzhaev, V.B.; Campbell, E.E.B.

2001-01-01

A brief state-of-the-art review in the field of cluster-surface interactions is presented. Ionised cluster beams could become a powerful and versatile tool for the modification and processing of surfaces as an alternative to ion implantation and ion assisted deposition. The main effects of cluster-surface collisions and possible applications of cluster ion beams are discussed. The outlooks of the Cluster Implantation and Deposition Apparatus (CIDA) being developed in Guteborg University are shown

Progress in ETA-II magnetic field alignment using stretched wire and low energy electron beam techniques

International Nuclear Information System (INIS)

Griffith, L.V.; Deadrick, F.J.

1991-01-01

Flux line alignment of the solenoidal focus magnets used on the ETA-II linear induction accelerator is a key element leading to a reduction of beam corkscrew motion. Two techniques have been used on the ETA-II accelerator to measure and establish magnet alignment. A low energy electron beam has been used to directly map magnetic field lines, and recent work has utilized a pulsed stretched wire technique to measure magnet tilts and offsets with respect to a reference axis. This paper reports on the techniques used in the ETA-II accelerator alignment, and presents results from those measurements which show that accelerator is magnetically aligned to within ∼ ± 200 microns

Improvements in technique for determining the surfactant penetration in hair fibres using scanning ion beam analyses

International Nuclear Information System (INIS)

Hollands, R.; Clough, A.S.; Meredith, P.

1999-01-01

The penetration abilities of surfactants need to be known by companies manufacturing hair-care products. In this work three complementary techniques were used simultaneously - PIXE, NRA and RBS - to measure the penetration of a surfactant, which had been deuterated, into permed hair fibres. Using a scanning micro-beam of 2 MeV 3 He ions 2-dimensional concentration maps were obtained which showed whether the surfactant penetrated the fibre or just stayed on the surface. This is the first report of the use of three simultaneous scattering techniques with a scanning micro-beam. (author)

Measurement of g factors of excited states in radioactive beams by the transient field technique: 132Te

International Nuclear Information System (INIS)

Benczer-Koller, N.; Kumbartzki, G.; Gurdal, G; Gross, Carl J; Krieger, B; Hatarik, Robert; O'Malley, Patrick; Pain, S. D.; Segen, L.; Baktash, Cyrus; Bingham, C. R.; Danchev, M.; Grzywacz, R.; Mazzocchi, C.

2008-01-01

The g factor of the 2 1 + state in 52 132 Te, E(2 1 + ) = 0.9739 MeV, r = 2.6 ps, was measured by the transient field technique applied to a radioactive beam. The development of an experimental approach necessary for work in radioactive beam environments is described. The result g = 0.28(15) agrees with the previous measurement by the recoil-in-vacuum technique, but here the sign of the g factor is measured as well

High current density ion beam measurement techniques

International Nuclear Information System (INIS)

Ko, W.C.; Sawatzky, E.

1976-01-01

High ion beam current measurements are difficult due to the presence of the secondary particles and beam neutralization. For long Faraday cages, true current can be obtained only by negative bias on the target and by summing the cage wall and target currents; otherwise, the beam will be greatly distorted. For short Faraday cages, a combination of small magnetic field and the negative target bias results in correct beam current. Either component alone does not give true current

Metaoptics for Spectral and Spatial Beam Manipulation

Science.gov (United States)

Raghu Srimathi, Indumathi

Laser beam combining and beam shaping are two important areas with applications in optical communications, high power lasers, and atmospheric propagation studies. In this dissertation, metaoptical elements have been developed for spectral and spatial beam shaping, and multiplexing. Beams carrying orbital angular momentum (OAM), referred to as optical vortices, have unique propagation properties. Optical vortex beams carrying different topological charges are orthogonal to each other and have low inter-modal crosstalk which allows for them to be (de)multiplexed. Efficient spatial (de)multiplexing of these beams have been carried out by using diffractive optical geometrical coordinate transformation elements. The spatial beam combining technique shown here is advantageous because the efficiency of the system is not dependent on the number of OAM states being combined. The system is capable of generating coaxially propagating beams in the far-field and the beams generated can either be incoherently or coherently multiplexed with applications in power scaling and dynamic intensity profile manipulations. Spectral beam combining can also be achieved with the coordinate transformation elements. The different wavelengths emitted by fiber sources can be spatially overlapped in the far-field plane and the generated beams are Bessel-Gauss in nature with enhanced depth of focus properties. Unique system responses and beam shapes in the far-field can be realized by controlling amplitude, phase, and polarization at the micro-scale. This has been achieved by spatially varying the structural parameters at the subwavelength scale and is analogous to local modification of material properties. With advancements in fabrication technology, it is possible to control not just the lithographic process, but also the deposition process. In this work, a unique combination of spatial structure variations in conjunction with the conformal coating properties of an atomic layer deposition tool

Nanomanufacturing of titania interfaces with controlled structural and functional properties by supersonic cluster beam deposition

International Nuclear Information System (INIS)

Podestà, Alessandro; Borghi, Francesca; Indrieri, Marco; Bovio, Simone; Piazzoni, Claudio; Milani, Paolo

2015-01-01

Great emphasis is placed on the development of integrated approaches for the synthesis and the characterization of ad hoc nanostructured platforms, to be used as templates with controlled morphology and chemical properties for the investigation of specific phenomena of great relevance in interdisciplinary fields such as biotechnology, medicine, and advanced materials. Here, we discuss the crucial role and the advantages of thin film deposition strategies based on cluster-assembling from supersonic cluster beams. We select cluster-assembled nanostructured titania (ns-TiO 2 ) as a case study to demonstrate that accurate control over morphological parameters can be routinely achieved, and consequently, over several relevant interfacial properties and phenomena, like surface charging in a liquid electrolyte, and proteins and nanoparticles adsorption. In particular, we show that the very good control of nanoscale morphology is obtained by taking advantage of simple scaling laws governing the ballistic deposition regime of low-energy, mass-dispersed clusters with reduced surface mobility

Nanomanufacturing of titania interfaces with controlled structural and functional properties by supersonic cluster beam deposition

Energy Technology Data Exchange (ETDEWEB)

Podestà, Alessandro, E-mail: alessandro.podesta@mi.infn.it, E-mail: pmilani@mi.infn.it; Borghi, Francesca; Indrieri, Marco; Bovio, Simone; Piazzoni, Claudio; Milani, Paolo, E-mail: alessandro.podesta@mi.infn.it, E-mail: pmilani@mi.infn.it [Centro Interdisciplinare Materiali e Interfacce Nanostrutturati (C.I.Ma.I.Na.), Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)

2015-12-21

Great emphasis is placed on the development of integrated approaches for the synthesis and the characterization of ad hoc nanostructured platforms, to be used as templates with controlled morphology and chemical properties for the investigation of specific phenomena of great relevance in interdisciplinary fields such as biotechnology, medicine, and advanced materials. Here, we discuss the crucial role and the advantages of thin film deposition strategies based on cluster-assembling from supersonic cluster beams. We select cluster-assembled nanostructured titania (ns-TiO{sub 2}) as a case study to demonstrate that accurate control over morphological parameters can be routinely achieved, and consequently, over several relevant interfacial properties and phenomena, like surface charging in a liquid electrolyte, and proteins and nanoparticles adsorption. In particular, we show that the very good control of nanoscale morphology is obtained by taking advantage of simple scaling laws governing the ballistic deposition regime of low-energy, mass-dispersed clusters with reduced surface mobility.

Mechanical properties of silicon oxynitride thin films prepared by low energy ion beam assisted deposition

International Nuclear Information System (INIS)

Shima, Yukari; Hasuyama, Hiroki; Kondoh, Toshiharu; Imaoka, Yasuo; Watari, Takanori; Baba, Koumei; Hatada, Ruriko

1999-01-01

Silicon oxynitride (SiO x N y ) films (0.1-0.7 μm) were produced on Si (1 0 0), glass and 316L stainless steel substrates by ion beam assisted deposition (IBAD) using Si evaporation and the concurrent bombardment with a mixture of 200 eV N 2 and Ar, or O 2 and Ar ions. Adhesion was evaluated by pull-off tests. Film hardness was measured by a nanoindentation system with AFM. The measurement of internal stress in the films was carried out by the Stoney method. The film structure was examined by GXRD. XPS was employed to measure the composition of films and to analyze the chemical bonds. The dependence of mechanical properties on the film thickness and the processing temperature during deposition was studied. Finally, the relations between the mechanical properties of the films and the correlation with corrosion-protection ability of films are discussed and summarized

Nanomanufacturing of titania interfaces with controlled structural and functional properties by supersonic cluster beam deposition

Science.gov (United States)

Podestà, Alessandro; Borghi, Francesca; Indrieri, Marco; Bovio, Simone; Piazzoni, Claudio; Milani, Paolo

2015-12-01

Great emphasis is placed on the development of integrated approaches for the synthesis and the characterization of ad hoc nanostructured platforms, to be used as templates with controlled morphology and chemical properties for the investigation of specific phenomena of great relevance in interdisciplinary fields such as biotechnology, medicine, and advanced materials. Here, we discuss the crucial role and the advantages of thin film deposition strategies based on cluster-assembling from supersonic cluster beams. We select cluster-assembled nanostructured titania (ns-TiO2) as a case study to demonstrate that accurate control over morphological parameters can be routinely achieved, and consequently, over several relevant interfacial properties and phenomena, like surface charging in a liquid electrolyte, and proteins and nanoparticles adsorption. In particular, we show that the very good control of nanoscale morphology is obtained by taking advantage of simple scaling laws governing the ballistic deposition regime of low-energy, mass-dispersed clusters with reduced surface mobility.

Verification of high efficient broad beam cold cathode ion source

Energy Technology Data Exchange (ETDEWEB)

Abdel Reheem, A. M., E-mail: amreheem2009@yahoo.com [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.N.13759, Cairo (Egypt); Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), Cairo (Egypt); Ahmed, M. M. [Physics Department, Faculty of Science, Helwan University, Cairo (Egypt); Abdelhamid, M. M.; Ashour, A. H. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), Cairo (Egypt)

2016-08-15

An improved form of cold cathode ion source has been designed and constructed. It consists of stainless steel hollow cylinder anode and stainless steel cathode disc, which are separated by a Teflon flange. The electrical discharge and output characteristics have been measured at different pressures using argon, nitrogen, and oxygen gases. The ion exit aperture shape and optimum distance between ion collector plate and cathode disc are studied. The stable discharge current and maximum output ion beam current have been obtained using grid exit aperture. It was found that the optimum distance between ion collector plate and ion exit aperture is equal to 6.25 cm. The cold cathode ion source is used to deposit aluminum coating layer on AZ31 magnesium alloy using argon ion beam current which equals 600 μA. Scanning electron microscope and X-ray diffraction techniques used for characterizing samples before and after aluminum deposition.

A novel technique for tuning of co-axial cavity of multi-beam klystron

Energy Technology Data Exchange (ETDEWEB)

Saha, Sukalyan, E-mail: sstechno18@gmail.com; Bandyopadhyay, Ayan Kumar; Pal, Debashis; Kant, Deepender; Joshi, Lalit Mohan; Kumar, Bijendra; Meena, Rakesh; Rawat, Vikram [Microwave Tubes Division, CSIR-CEERI, Pilani, Rajasthan-333031 (India)

2016-03-09

Multi-beam Klystrons (MBKs) have gained wide acceptances in the research sector for its inherent advantages. But developing a robust tuning technique for an MBK cavity of coaxial type has still remained a challenge as these designs are very prone to suffer from asymmetric field distribution with inductive tuning of the cavity. Such asymmetry leads to inhomogeneous beam-wave interaction, an undesirable phenomenon. Described herein is a new type of coaxial cavity that has the ability to suppress the asymmetry, thereby allowing tuning of the cavity with a single tuning post.

Synthesis of carbon-13 labelled carbonaceous deposits and their evaluation for potential use as surrogates to better understand the behaviour of the carbon-14-containing deposit present in irradiated PGA graphite

Energy Technology Data Exchange (ETDEWEB)

Payne, L., E-mail: liam.payne@bristol.ac.uk [Interface Analysis Centre, HH Wills Physics Laboratory, University of Bristol, BS8 1TL (United Kingdom); Walker, S.; Bond, G. [Centre for Materials Science, University of Central Lancashire, PR1 2HE (United Kingdom); Eccles, H. [John Tyndall Institute for Nuclear Research, School of Computing, Engineering and Physical Sciences, University of Central Lancashire, PR1 2HE (United Kingdom); Heard, P.J.; Scott, T.B. [Interface Analysis Centre, HH Wills Physics Laboratory, University of Bristol, BS8 1TL (United Kingdom); Williams, S.J. [Radioactive Waste Management, B587, Curie Avenue, Harwell Oxford, Didcot, OX11 0RH (United Kingdom)

2016-03-15

The present work has used microwave plasma chemical vapour deposition to generate suitable isotopically labelled carbonaceous deposits on the surface of Pile Grade A graphite for use as surrogates for studying the behaviour of the deposits observed on irradiated graphite extracted from UK Magnox reactors. These deposits have been shown elsewhere to contain an enhanced concentration of {sup 14}C compared to the bulk graphite. A combination of Raman spectroscopy, ion beam milling with scanning electron microscopy and secondary ion mass spectrometry were used to determine topography and internal morphology in the formed deposits. Direct comparison was made against deposits found on irradiated graphite samples trepanned from a Magnox reactor core and showed a good similarity in appearance. This work suggests that the microwave plasma chemical vapour deposition technique is of value in producing simulant carbon deposits, being of sufficiently representative morphology for use in non-radioactive surrogate studies of post-disposal behaviour of {sup 14}C-containing deposits on some irradiated Magnox reactor graphite.

The Development of a Differential Deposition Technique for Figure Correction in Grazing Incidence Optics