WorldWideScience

Sample records for beam physical vapor

  1. Nanostructured component fabrication by electron beam-physical vapor deposition

    Science.gov (United States)

    Singh, Jogender; Wolfe, Douglas E.

    2005-08-01

    Fabrication of cost-effective, nano-grained net-shaped components has brought considerable interest to Department of Defense, National Aeronautics and Space Administration, and Department of Energy. The objective of this paper is to demonstrate the versatility of electron beam-physical vapor deposition (EB-PVD) technology in engineering new nanostructured materials with controlled microstructure and microchemistry in the form of coatings and net-shaped components for many applications including the space, turbine, optical, biomedical, and auto industries. Coatings are often applied on components to extent their performance and life under severe environmental conditions including thermal, corrosion, wear, and oxidation. Performance and properties of the coatings depend upon their composition, microstructure, and deposition condition. Simultaneous co-evaporation of multiple ingots of different compositions in the high energy EB-PVD chamber has brought considerable interest in the architecture of functional graded coatings, nano-laminated coatings, and design of new structural materials that could not be produced economically by conventional methods. In addition, high evaporation and condensate rates allowed fabricating precision net-shaped components with nanograined microstructure for various applications. Using EB-PVD, nano-grained rhenium (Re) coatings and net-shaped components with tailored microstructure and properties were fabricated in the form of tubes, plates, and Re-coated spherical graphite cores. This paper will also present the results of various metallic and ceramic coatings including chromium, titanium carbide (TiC), titanium diboride (TiB2), hafnium nitride (HfN), titanium-boron-carbonitride (TiBCN), and partially yttria stabilized zirconia (YSZ) TBC coatings deposited by EB-PVD for various applications.

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

    International Nuclear Information System (INIS)

    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.

  3. Electron beam-physical vapor deposition of SiC/SiO 2 high emissivity thin film

    Science.gov (United States)

    Yi, Jian; He, XiaoDong; Sun, Yue; Li, Yao

    2007-02-01

    When heated by high-energy electron beam (EB), SiC can decompose into C and Si vapor. Subsequently, Si vapor reacts with metal oxide thin film on substrate surface and formats dense SiO 2 thin film at high substrate temperature. By means of the two reactions, SiC/SiO 2 composite thin film was prepared on the pre-oxidized 316 stainless steel (SS) substrate by electron beam-physical vapor deposition (EB-PVD) only using β-SiC target at 1000 °C. The thin film was examined by energy dispersive spectroscopy (EDS), grazing incidence X-ray asymmetry diffraction (GIAXD), scanning electron microscopy (SEM), atomic force microscopy (AFM), backscattered electron image (BSE), electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS) and Fourier transformed infra-red (FT-IR) spectroscopy. The analysis results show that the thin film is mainly composed of imperfect nano-crystalline phases of 3C-SiC and SiO 2, especially, SiO 2 phase is nearly amorphous. Moreover, the smooth and dense thin film surface consists of nano-sized particles, and the interface between SiC/SiO 2 composite thin film and SS substrate is perfect. At last, the emissivity of SS substrate is improved by the SiC/SiO 2 composite thin film.

  4. Evolution of microstructure during the growth of thermal barrier coatings by electron-beam physical vapor deposition

    Science.gov (United States)

    Terry, Scott Gregory

    2001-12-01

    The mechanisms responsible for the formation of porosity and crystallographic orientation (texture) in the microstructure of thermal barrier coatings (TBCs) grown by electron-beam physical vapor deposition (EB-PVD) are investigated. A matrix of 7 wt.% Y2O3-ZrO2 TBC specimens was generated by independently varying two processing parameters: substrate temperature (Ts) and pattern of vapor incidence. TBCs deposited on stationary substrates oriented normal to the vapor source yielded columnar microstructures possessing fiber textures. Growth directions changed from to + to + as Ts increased from 900-1100°C. Increasing the angle of vapor incidence to 45° favored biaxially aligned columnar growth in the direction, while rotating the substrates produced biaxially aligned columns. The texture orientation is correlated with the observed column tip morphologies by considering the growth directions defined by symmetric arrangements of {111} preferred growth planes about a column axis. The change in texture orientation with increasing Ts under normal incidence on stationary substrates is linked to changes in the mechanism of crystal growth. The pattern of vapor incidence on stationary oblique and rotated substrates has a stronger influence on texture than Ts. Here, the requirement that faces composing a column tip receive equal amounts of vapor flux determines the outcome of a competitive growth process yielding the observed biaxial orientations. The formation of porosity is in general attributed to shadowing of the incident vapor by geometric features of the TBC surface. These features are crystallographic in nature such that the formation of porosity is intimately tied to the crystallographic texture of the coating. Intercolumnar gaps are generated by the interaction between the pattern of vapor incidence and the column tip morphology, whereas the feather-like shape of the open intracolumnar porosity evolves from shadows cast by steps on the column tip faces. Closed

  5. Microstructure and thermal cycling behavior of CeO2 coatings deposited by the electron beam physical vapor technique

    International Nuclear Information System (INIS)

    Excellent thermal shock resistance is required for thermal protection coatings experiencing high/low temperature cycles. In this paper, the pure ceria oxide coatings were deposited by electron beam physical vapor technique at different power densities. The grain orientation, morphology, hardness and thermal cycling oxidation behavior of CeO2 coatings were systematically studied. The deposition power density has remarkable influence on the preferred crystal orientation and morphology of the coatings. The heating–cooling test cycles from 1000 °C to room temperature indicate that the CeO2 coatings with the columnar structure show excellent thermal shock resistance. The hardness of the CeO2 coating varies with thermal cycling. - Highlights: • Electron-beam physical vapor deposited CeO2 coatings show preferred orientation. • Surface morphology of CeO2 coatings is deeply influenced by the deposition power. • CeO2 coatings with columnar structure exhibit excellent thermal shock resistance. • The hardness increases initially and then decreases during thermal cycling

  6. Thickness and component distributions of yttrium-titanium alloy films in electron-beam physical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    LI ShuaiHui; SHU YongHua; FAN Jing

    2008-01-01

    Thickness and component distributions of large-area thin films are an issue of in-ternational concern in the field of material processing. The present wor0k employs experiments and direct simulation Monte Carlo (DSMC) method to investigate three-dimensional low-density, non-equilibrium jets of yttrium and titanium vapor atoms in an electron-beams physical vapor deposition (EBPVD) system furnished with two or three electron-beams, and obtains their deposition thickness and component distributions onto 4-inch and 6-inch mono-crystal silicon wafers. The DSMC results are found in excellent agreement with our measurements, such as evaporation rates of yttrium and titanium measured in-situ by quartz crystal reso-nators, deposited film thickness distribution measured by Rutherford backscat-tering spectrometer (RBS) and surface profilometer and deposited film molar ratio distribution measured by RBS and inductively coupled plasma atomic emission spectrometer (ICP-AES). This can be taken as an indication that a combination of DSMC method with elaborate measurements may be satisfactory for predicting and designing accurately the transport process of EBPVD at the atomic level.

  7. Structural and growth aspects of electron beam physical vapor deposited NiO-CeO2 nanocomposite films

    International Nuclear Information System (INIS)

    Deposition of composite materials as thin film by electron beam physical vapor deposition technique (EB-PVD) still remains as a challenge. Here, the authors report the deposition of NiO-CeO2 (30/70 wt. %) composites on quartz substrate by EB-PVD. Two NiO-CeO2 nanocomposite targets—one as green compact and the other after sintering at 1250 °C—were used for the deposition. Though the targets varied with respect to physical properties such as crystallite size (11–45 nm) and relative density (44% and 96%), the resultant thin films exhibited a mean crystallite size in the range of 20–25 nm underlining the role of physical nature of deposition. In spite of the crystalline nature of the targets and similar elemental concentration, a transformation from amorphous to crystalline structure was observed in thin films on using sintered target. Postannealing of the as deposited film at 800 °C resulted in a polycrystalline structure consisting of CeO2 and NiO. Deposition using pure CeO2 or NiO as target resulted in the preferential orientation toward (111) and (200) planes, respectively, showing the influence of adatoms on the evaporation and growth process of NiO-CeO2 composite. The results demonstrate the influence of electron beam gun power on the adatom energy for the growth process of composite oxide thin films

  8. Electron Beam-Physical Vapor Deposited TiAl-based Laminated Composite Sheet with Nb Layer Toughening

    Institute of Scientific and Technical Information of China (English)

    ZHANG De-ming; CHEN Gui-qing; HAN Jie-cai; MENG Song-he

    2006-01-01

    The TiAl-based laminated composite sheet of 150 mm × 100 mm × 0.2 mm, with 24 TiAl layers and 23 Nb layers laid alternately one on another, was successfully fabricated using the electron beam-physical vapor deposition (EB-PVD) method. The microstructure and properties of the sheet were investigated on an atomic force microscope (AFM), a scanning electron microscope (SEM) and a tensile testing machine. The results indicate that the evenly distributed Nb layers are well joined with the TiAl layers, and the interfaces between layers are transparent, and every interlayer spacing is of about 8 μm. The fractures appear to be a mixture of intergranular fractures and somewhat ductile quasi-cleavage ones. Despite its slight influence on ultimate tensile strength, the inserts of Nb layers efficiently increase the room temperature ductility of TiAl-based alloys due to the crack deflection effect.

  9. Hydroxyapatite coating on the Ti-35Nb-xZr alloy by electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the hydroxyapatite coating on the Ti-35Nb-xZr alloy by electron beam-physical vapor deposition. The Ti-35Nb-xZr ternary alloys contained from 3 wt.% to 10 wt.% Zr content were manufactured by arc melting furnace. Hydroxyapatite (HA) coatings were prepared by electron-beam physical vapor deposition (EB-PVD) method, and crystallization treatment was performed in Ar atmosphere at 300 and 500 deg. C for 1 h. The coated surface morphology of Ti-35Nb-xZr alloy was examined by FE-SEM, EDX and XRD, respectively. In order to evaluate the corrosion behavior, the tests were performed by potentiodynamic, cyclic polarization and AC impedance test. All the electrochemical data were obtained using a potentiostat. The Ti-35Nb-xZr alloys exhibited equiaxed structure with β phase, the peak of β phase increased with Zr contents. The hardness and elastic modulus of Ti-35Nb-xZr alloys decreased as Zr content increased. The HA coated layer was approximately 150 nm and Ca/P ratio of HA coated surface after heat treatment at 500 deg. C was around 1.67. The HA thin film consisted of small droplets with spherical shape by crystallization. From the anodic polarization curves, HA coated and heat treated Ti-35Nb-10Zr alloy showed higher corrosion potential than other samples. HA coated film on the Ti-35Nb-10Zr alloy can be shown high polarization resistance by crystallization.

  10. Hydroxyapatite coating on the Ti-35Nb-xZr alloy by electron beam-physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong-Hoon [Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave. Columbus, OH (United States); Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials and Research Center for Oral Disease Regulation of the Aged, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials and Research Center for Oral Disease Regulation of the Aged, Chosun University, Gwangju (Korea, Republic of); Eun, Sang-Won [Department of Applied Advanced Materials, Korea Polytechnic V Colleges (Korea, Republic of)

    2011-08-01

    The aim of this study was to investigate the hydroxyapatite coating on the Ti-35Nb-xZr alloy by electron beam-physical vapor deposition. The Ti-35Nb-xZr ternary alloys contained from 3 wt.% to 10 wt.% Zr content were manufactured by arc melting furnace. Hydroxyapatite (HA) coatings were prepared by electron-beam physical vapor deposition (EB-PVD) method, and crystallization treatment was performed in Ar atmosphere at 300 and 500 deg. C for 1 h. The coated surface morphology of Ti-35Nb-xZr alloy was examined by FE-SEM, EDX and XRD, respectively. In order to evaluate the corrosion behavior, the tests were performed by potentiodynamic, cyclic polarization and AC impedance test. All the electrochemical data were obtained using a potentiostat. The Ti-35Nb-xZr alloys exhibited equiaxed structure with {beta} phase, the peak of {beta} phase increased with Zr contents. The hardness and elastic modulus of Ti-35Nb-xZr alloys decreased as Zr content increased. The HA coated layer was approximately 150 nm and Ca/P ratio of HA coated surface after heat treatment at 500 deg. C was around 1.67. The HA thin film consisted of small droplets with spherical shape by crystallization. From the anodic polarization curves, HA coated and heat treated Ti-35Nb-10Zr alloy showed higher corrosion potential than other samples. HA coated film on the Ti-35Nb-10Zr alloy can be shown high polarization resistance by crystallization.

  11. Composition, structure and properties of gradient thermal barrier coatings (TBCs) produced by electron beam physical vapor deposition (EB-PVD)

    International Nuclear Information System (INIS)

    Gradient thermal barrier coatings (TBCs) along with the bond coat were produced by one and the same technological cycle using electron beam physical vapor deposition (EB-PVD) of an MCrAlY ingot, then of an Al-Al2O3-ZrO2(Y2O3) tablet (pressed multicomponent powder mixture) and finally of a ZrO2-7 wt.% Y2O3 ceramic ingot. At the evaporation temperature used, vapor pressures of the tablet components decrease in the direction: AlapproachesAl2O3approachesZrO2(Y2O3). The evaporation of these constituents also proceeds in the same order. As a result, a transition zone [with composition and structure gradients - transition gradient zone (TGZ)] - forms between the bond coat and outer ZrO2-7 wt.% Y2O3 ceramic layer during deposition. The TGZ constitution and structure are primarily determined by the aluminum, Al2O3 and ZrO2 contents of the tablet. As a consequence of liquid aluminum participation in the coating deposition process, a thin layer of β-phase (NiAl), smoothly transitions to an Al2O3 layer and then to ZrO2-7 wt.% Y2O3. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. Structural and growth aspects of electron beam physical vapor deposited NiO-CeO{sub 2} nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Kuanr, Sushil Kumar; K, Suresh Babu, E-mail: sureshbabu.nst@pondiuni.edu.in [Centre for Nanoscience and Technology, Madanjeet School of Green Energy Technologies, Pondicherry University, Puducherry 605 014 (India)

    2016-03-15

    Deposition of composite materials as thin film by electron beam physical vapor deposition technique (EB-PVD) still remains as a challenge. Here, the authors report the deposition of NiO-CeO{sub 2} (30/70 wt. %) composites on quartz substrate by EB-PVD. Two NiO-CeO{sub 2} nanocomposite targets—one as green compact and the other after sintering at 1250 °C—were used for the deposition. Though the targets varied with respect to physical properties such as crystallite size (11–45 nm) and relative density (44% and 96%), the resultant thin films exhibited a mean crystallite size in the range of 20–25 nm underlining the role of physical nature of deposition. In spite of the crystalline nature of the targets and similar elemental concentration, a transformation from amorphous to crystalline structure was observed in thin films on using sintered target. Postannealing of the as deposited film at 800 °C resulted in a polycrystalline structure consisting of CeO{sub 2} and NiO. Deposition using pure CeO{sub 2} or NiO as target resulted in the preferential orientation toward (111) and (200) planes, respectively, showing the influence of adatoms on the evaporation and growth process of NiO-CeO{sub 2} composite. The results demonstrate the influence of electron beam gun power on the adatom energy for the growth process of composite oxide thin films.

  13. A Comparison of the Effects of RF Plasma Discharge and Ion Beam Supply on the Growth of Cubic Boron Nitride Films Formed by Laser Physical Vapor Deposition

    Science.gov (United States)

    Kaneda, Kayo; Shibata, Kimihiro

    1994-01-01

    This paper presents a comparison of the effects of RF plasma discharge and ion beam supply on the growth of cubic boron nitride films formed by excimer laser physical vapor deposition (laser PVD). The film structure was analyzed by fourier transformation infrared region (FT-IR) spectroscopy and thin-film X-ray diffraction analysis. The structure of the film deposited with an RF plasma discharge provided between the substrate and target was hexagonal BN. On the other hand, that of the film deposited by irradiating the substrate directly with an ion beam was hexagonal BN (hBN) and cubic BN (cBN). It is thought that direct irradiation of the vapor generated from the target by accelerated ions increased the activation energy of the vapor, with the result that the film structure was changed. Besides irradiating the substrate directly with the ion beam resulted primarily in the etching of hBN while cBN remained.

  14. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    International Nuclear Information System (INIS)

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y2O3-stabilized-ZrO2 (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs

  15. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhenhua, E-mail: zhxuciac@163.com [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Dai, Jianwei [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Niu, Jing [Shenyang Liming Aero-engine (Group) Corporation Ltd., Institute of Metallurgical Technology, Technical Center, Shengyang 110043 (China); Li, Na; Huang, Guanghong; He, Limin [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China)

    2014-12-25

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs.

  16. Thermal barrier coating of lanthanum-zirconium-cerium composite oxide made by electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    Lanthanum-zirconium-cerium composite oxide (La2(Zr0.7Ce0.3)2O7, LZ7C3) as a candidate material for thermal barrier coatings (TBCs) was prepared by electron beam-physical vapor deposition (EB-PVD). The composition, crystal structure, thermophysical properties, surface and cross-sectional morphologies and cyclic oxidation behavior of the LZ7C3 coating were studied. The results indicated that LZ7C3 has a high phase stability between 298 K and 1573 K, and its linear thermal expansion coefficient (TEC) is similar to that of zirconia containing 8 wt% yttria (8YSZ). The thermal conductivity of LZ7C3 is 0.87 W m-1 K-1 at 1273 K, which is almost 60% lower than that of 8YSZ. The deviation of coating composition from the ingot can be overcome by the addition of excess CeO2 and ZrO2 during ingot preparation or by adjusting the process parameters. The failure of the LZ7C3 coating is mainly a result of the occurrence of micro-cracks inside ceramic topcoat, which cause the abnormal oxidation of bond coat.

  17. Failure mechanisms of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Science.gov (United States)

    Vaidyanathan, Krishnakumar

    Thermal barrier coatings (TBCs) allow operation of structural components, such as turbine blades and vanes in industrial and aircraft gas engines, at temperatures close to the substrate melting temperatures. They consist of four different layers; a high strength creep-resistant nickel-based superalloy substrate, an oxidation resistant bond coat (BC), a low thermal conductivity ceramic topcoat and a thermally grown oxide (TGO), that is predominantly alpha-Al 2O3, that forms between the BC and the TBC. Compressive stresses (3--5 GPa) that are generated in the thin TGO (0.25--8 mum) due to the mismatch in thermal coefficient of expansion between the TGO and BC play a critical role in the failure of these coatings. In this study, the failure mechanisms of a commercial yttria-stabilized zirconia (7YSZ) electron beam-physical vapor deposited (EB-PVD) coating on platinum aluminide (beta-(Ni,Pt)Al) bond coat have been identified. Two distinct mechanisms have been found responsible for the observed damage initiation and progression at the TGO/bond coat interface. The first mechanism leads to localized debonding at TGO/bond coat interface due to increased out-of-plane tensile stress, along bond coat features that manifest themselves as ridges. The second mechanism causes cavity formation at the TGO/bond coat interface, driven by cyclic plasticity of the bond coat. It has been found that the debonding at the TGO/bond coat interface due to the first mechanism is solely life determining. The final failure occurs by crack extension along either the TGO/bond coat interface or the TGO/YSZ interface or a combination of both, leading to large scale buckling. Based on these mechanisms, it is demonstrated that the bond coat grain size and the aspect ratio of the ridges have a profound influence on spallation lives of the coating. The removal of these ridges by fine polishing prior to TBC deposition led to a four-fold improvement in life. The failure mechanism identified for the

  18. Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO2 anatase, TiO2 rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower Icorr than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO2, HA, and Ca5(PO4)2SiO4. • Polarization resistance of the coating was increased by Si substitution in HA

  19. Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong-Hoon [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States); Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States)

    2013-11-01

    The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO{sub 2} anatase, TiO{sub 2} rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower I{sub corr} than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO{sub 2}, HA, and Ca{sub 5}(PO{sub 4}){sub 2}SiO{sub 4}. • Polarization resistance of the coating was increased by Si substitution in HA.

  20. Focusing Light Beams To Improve Atomic-Vapor Optical Buffers

    Science.gov (United States)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatoliy

    2010-01-01

    Specially designed focusing of light beams has been proposed as a means of improving the performances of optical buffers based on cells containing hot atomic vapors (e.g., rubidium vapor). There is also a companion proposal to improve performance by use of incoherent optical pumping under suitable conditions. Regarding the proposal to use focusing: The utility of atomic-vapor optical buffers as optical storage and processing devices has been severely limited by nonuniform spatial distributions of intensity in optical beams, arising from absorption of the beams as they propagate in atomic-vapor cells. Such nonuniformity makes it impossible to optimize the physical conditions throughout a cell, thereby making it impossible to optimize the performance of the cell as an optical buffer. In practical terms simplified for the sake of brevity, "to optimize" as used here means to design the cell so as to maximize the group delay of an optical pulse while keeping the absorption and distortion of the pulse reasonably small. Regarding the proposal to use incoherent optical pumping: For reasons too complex to describe here, residual absorption of light is one of the main impediments to achievement of desirably long group delays in hot atomic vapors. The present proposal is directed toward suppressing residual absorption of light. The idea of improving the performance of slow-light optical buffers by use of incoherent pumping overlaps somewhat with the basic idea of Raman-based slow-light systems. However, prior studies of those systems did not quantitatively answer the question of whether the performance of an atomic vapor or other medium that exhibits electromagnetically induced transparency (EIT) with Raman gain is superior to that of a medium that exhibits EIT without Raman gain.

  1. Nuclear physics with radioactive beams

    International Nuclear Information System (INIS)

    Radioactive beam production through two different mechanisms: acceleration of radioactive nuclei, and production of secondary beams from projectile fragmentation is overviewed. Some topics of the applications of radioactive beams in nuclear physics, such as identification and study of exotic nuclei, neutron halos, nuclear astrophysics and medical applications are discussed. (K.A.). 24 refs., 8 figs

  2. Physical vapor deposition and patterning of calcium fluoride films

    International Nuclear Information System (INIS)

    Physical vapor deposition of calcium fluoride (CaF2) thin films was performed via electron beam evaporation, resistive/thermal evaporation, and nonreactive radio frequency sputtering. Patterning of the resultant ''usable'' thin films was then also attempted in several ways, including by shadow mask deposition, liftoff, and direct chemical etching. Resistive evaporation produced the most stable films, having polycrystalline morphology with a moderately strong preference to the 331 orientation. The cleanest patterning results were obtained via a polymer/metal liftoff. The results and implications of each of the various deposition and patterning techniques are discussed.

  3. Center for Beam Physics, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-06-01

    This report contains the following information on the center for beam physics: Facilities; Organizational Chart; Roster; Profiles of Staff; Affiliates; Center Publications (1991--1993); and 1992 Summary of Activities.

  4. Center for Beam Physics, 1992

    International Nuclear Information System (INIS)

    This report contains the following information on the center for beam physics: Facilities; Organizational Chart; Roster; Profiles of Staff; Affiliates; Center Publications (1991--1993); and 1992 Summary of Activities

  5. Melt and vapor characteristics in an electron beam evaporator

    International Nuclear Information System (INIS)

    Two different approaches have been compared for the calculation of the free surface temperature Ts in cerium or copper evaporation experiments: the first method considers properties of the melt: an empirical law is used to take into account turbulent thermal convection, instabilities and characterization of the free surface. The second method considers the vapor flow expansion and connects Ts to the measured terminal temperature and terminal mean parallel velocity of the vapor jet, by direct simulation Monte Carlo calculations including an atom-atom inelastic collision algorithm. The agreement between the two approaches is better for cerium than for copper in the high characterization case. The analysis, from the point of view of the properties of the melt, of the terminal parameters of the vapor jet for the high beam powers shows that Ts and the Knudsen number at the vapour source reach a threshold when the beam power increases. (author). 12 figs., 1 tab., 21 refs

  6. External photon beams: Physical aspects

    International Nuclear Information System (INIS)

    Radiotherapy procedures fall into two main categories: external beam radiotherapy and brachytherapy. In external beam radiotherapy the radiation source is at a certain distance from the patient and the target within the patient is irradiated with an external radiation beam. In brachytherapy (see Chapter 13) radiation sources are placed directly into the target volume (intracavitary or interstitial brachytherapy) or on to a target (surface mould or intraoperative radiotherapy). Most external beam radiotherapy is carried out with photon beams, some with electron beams and a very small fraction with more exotic particles such as protons, heavier ions or neutrons. This chapter deals with external photon beam radiotherapy. Photon external beams are all characterized by the same physical parameters, but fall into various categories depending on their origin, means of production and energy. There are two origins of photon beams: g rays, which originate from radioactive nuclei, and X rays, which originate in a target bombarded with energetic electrons. The X rays from a target consist of bremsstrahlung photons and characteristic photons. X rays are produced either in an X ray tube (superficial or orthovoltage X rays) or in a linac (megavoltage X rays)

  7. Double-ceramic-layer thermal barrier coatings based on La2(Zr0.7Ce0.3)2O7/La2Ce2O7 deposited by electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    Double-ceramic-layer (DCL) thermal barrier coatings (TBCs) of La2(Zr0.7Ce0.3)2O7 (LZ7C3) and La2Ce2O7 (LC) were deposited by electron beam-physical vapor deposition (EB-PVD). The composition, interdiffusion, surface and cross-sectional morphologies, cyclic oxidation behavior of DCL coating were studied. Energy dispersive spectroscopy and X-ray diffraction analyses indicate that both LZ7C3 and LC coatings are effectively fabricated by a single LZ7C3 ingot with properly controlling the deposition energy. The chemical compatibility of LC coating and thermally grown oxide (TGO) layer is unstable. LaAlO3 is formed due to the chemical reaction between LC and Al2O3 which is the main composition of TGO layer. Additionally, the thermal cycling behavior of DCL coating is influenced by the interdiffusion of Zr and Ce between LZ7C3 and LC coatings. The failure of DCL coating is a result of the sintering of LZ7C3 coating surface, the chemical incompatibility of LC coating and TGO layer and the abnormal oxidation of bond coat. Since no single material that has been studied so far satisfies all the requirements for high temperature applications, DCL coating is an important development direction of TBCs.

  8. Compact electron-beam source for formation of neutral beams of very low vapor pressure materials

    International Nuclear Information System (INIS)

    An electron-beam heater and associated power supply have been developed for use in formation of metal vapors for neutral beam studies. The device is small with relatively low power (250 W). It is easily constructed and designed such that the target surface is normal to the direction of propagation of the neutral beam. Beams of tantalum atoms and carbon particles have been formed using the device

  9. Compact electron-beam source for formation of neutral beams of very low vapor pressure materials

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, J.A.; Vroom, D.A.

    1978-07-01

    An electron-beam heater and associated power supply have been developed for use in formation of metal vapors for neutral beam studies. The device is small with relatively low power (250 W). It is easily constructed and designed such that the target surface is normal to the direction of propagation of the neutral beam. Beams of tantalum atoms and carbon particles have been formed using the device.

  10. Physics opportunities with meson beams

    Energy Technology Data Exchange (ETDEWEB)

    Briscoe, William J.; Doering, Michael; Haberzettl, Helmut; Strakovsky, Igor I. [The George Washington University, Washington, DC (United States); Manley, D.M. [Kent State University, Kent, OH (United States); Naruki, Megumi [Kyoto University, Kyoto (Japan); Swanson, Eric S. [University of Pittsburgh, Pittsburgh, PA (United States)

    2015-10-15

    Over the past two decades, meson photo- and electroproduction data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even non-existent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledge in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a state-of-the-art meson-beam facility needs to be constructed. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility. (orig.)

  11. Physics Opportunities with Meson Beams

    CERN Document Server

    Briscoe, William J; Haberzettl, Helmut; Manley, D Mark; Naruki, Megumi; Strakovsky, Igor I; Swanson, Eric S

    2015-01-01

    Over the past two decades, meson photo- and electro-production data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even nonexistent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledge in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a state of-the-art meson-beam facility needs to be constructed. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility.

  12. Center for Beam Physics, 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-01

    The Center for Beam Physics is a multi-disciplinary research and development unit in the Accelerator and Fusion Research Division at Lawrence Berkeley Laboratory. At the heart of the Center`s mission is the fundamental quest for mechanisms of acceleration, radiation and focusing of energy. Dedicated to exploring the frontiers of the physics of (and with) particle and photon beams, its primary mission is to promote the science and technology of the production, manipulation, storage and control systems of charged particles and photons. The Center serves this mission via conceptual studies, theoretical and experimental research, design and development, institutional project involvement, external collaborations, association with industry and technology transfer. This roster provides a glimpse at the scientists, engineers, technical support, students, and administrative staff that make up this team and a flavor of their multifaceted activities during 1993.

  13. Center for Beam Physics, 1993

    International Nuclear Information System (INIS)

    The Center for Beam Physics is a multi-disciplinary research and development unit in the Accelerator and Fusion Research Division at Lawrence Berkeley Laboratory. At the heart of the Center's mission is the fundamental quest for mechanisms of acceleration, radiation and focusing of energy. Dedicated to exploring the frontiers of the physics of (and with) particle and photon beams, its primary mission is to promote the science and technology of the production, manipulation, storage and control systems of charged particles and photons. The Center serves this mission via conceptual studies, theoretical and experimental research, design and development, institutional project involvement, external collaborations, association with industry and technology transfer. This roster provides a glimpse at the scientists, engineers, technical support, students, and administrative staff that make up this team and a flavor of their multifaceted activities during 1993

  14. Physics with polarized electron beams

    International Nuclear Information System (INIS)

    As a distinct field, elementary particle physics is now approximately forty years old. In all that time, only a few of the thousands of experiments that have been performed have made use of spin polarized particle beams. There are two reasons for this lack of interest. The first is that spin polarized beams are difficult to produce, accelerate, and transport. The second reason is that any physical process that can occur during the collision of a polarized particle with another (polarized or not) can also occur during the collision of unpolarized particles. One might ask then, why has any effort been expended on the subject? The answer, at least in the case of polarized electron beams, is that electron accelerators and storage rings have in recent years achieved sufficient energy to begin to probe the weak interaction directly. The weak interaction distinguishes between left- and right-handed fermionic currents. Left-handed particles interact in a fundamentally different way than their right-handed counterparts. If the experimenter wishes to explore or exploit this difference, he (or she) must either prepare the spin state of the incident particles or analyze the spin state of outgoing particles. For reasons, of generality and improved statistical precision, the former is usually preferable to the latter. The first of these lectures will review some of the techniques necessary for the production, transport, and monitoring of polarized electron (or positron) beams. The second lecture will survey some of the physics possibilities of polarized electron--positron collisions. 33 refs., 26 figs., 5 tabs

  15. Physical vapor deposition of cubic boron nitride thin films

    International Nuclear Information System (INIS)

    Cubic boron nitride was successfully deposited using physical vapor-deposition methods. RF-sputtering, magnetron sputtering, dual-ion-beam deposition, and ion-beam-assisted evaporation were all used. The ion-assisted evaporation, using boron evaporation and bombardment by nitrogen and argon ions, led to successful cubic boron nitride growth over the widest and most controllable range of conditions. It was found that two factors were important for c-BN growth: bombardment of the growing film and the presence of argon. A systematic study of the deposition conditions was carried out. It was found that the value of momentum transferred into the growing from by the bombarding ions was critical. There was a very narrow transition range in which mixed cubic and hexagonal phase films were prepared. Momentum-per-atom value took into account all the variables involved in ion-assisted deposition: deposition rate, ion energy, ion flux, and ion species. No other factor led to the same control of the process. The role of temperature was also studied; it was found that at low temperatures only mixed cubic and hexagonal material are deposited

  16. A review-application of physical vapor deposition (PVD) and related methods in the textile industry

    Science.gov (United States)

    Shahidi, Sheila; Moazzenchi, Bahareh; Ghoranneviss, Mahmood

    2015-09-01

    Physical vapor deposition (PVD) is a coating process in which thin films are deposited by the condensation of a vaporized form of the desired film material onto the substrate. The PVD process is carried out in a vacuum. PVD processes include different types, such as: cathode arc deposition, electron beam physical vapor deposition, evaporative deposition, sputtering, ion plating and enhanced sputtering. In the PVD method, the solid coating material is evaporated by heat or by bombardment with ions (sputtering). At the same time, a reactive gas is also introduced; it forms a compound with the metal vapor and is deposited on the substrate as a thin film with highly adherent coating. Such coatings are used in a wide range of applications such as aerospace, automotive, surgical, medical, dyes and molds for all manner of material processing, cutting tools, firearms, optics, thin films and textiles. The objective of this work is to give a comprehensive description and review of the science and technology related to physical vapor deposition with particular emphasis on their potential use in the textile industry. Physical vapor deposition has opened up new possibilities in the modification of textile materials and is an exciting prospect for usage in textile design and technical textiles. The basic principle of PVD is explained and the major applications, particularly sputter coatings in the modification and functionalization of textiles, are introduced in this research.

  17. Silicidation of Niobium Deposited on Silicon by Physical Vapor Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Coumba Ndoye, Kandabara Tapily, Marius Orlowski, Helmut Baumgart, Diefeng Gu

    2011-07-01

    Niobium was deposited by physical vapor deposition (PVD) using e-beam evaporation on bare (100) silicon substrates and SiO2 surfaces. The formation of niobium silicide was investigated by annealing PVD Nb films in the temperatures range 400–1000°C. At all elevated annealing temperatures the resistivity of Nb silicide is substantially higher than that of Nb. The Nb silicidation as a function of temperature has been investigated and different NbXSiy compounds have been characterized. It has been observed that the annealing of the Nb film on Si is accompanied by a strong volume expansion of about 2.5 of the resulting reacted film. The films' structural properties were studied using X-Ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM), which was not previously presented in the context of the extant NbSi literature. The X-Ray diffraction characterization of the Nb on Si sample annealed at 1000°C, showed the presence of hexagonal Nb5Si3 phases, with a dominant peak at the (200) plane, and NbSi2 phases. Fractal dimension calculations indicate a distinct transition from Stranski-Krastanov to Volmer-Weber film growth for NbSi formation at the annealing temperature of 600°C and above.

  18. Low temperature laser physical vapor deposition of multilayered thin films

    International Nuclear Information System (INIS)

    The authors have investigated the formation of various multilayer thin films by the laser physical vapor deposition technique. A multi stage target holder was constructed to perform all process steps in-situ; target/substrate cleaning, deposition, and annealing. The laser physical vapor deposition technique offers many advantages over conventional physical vapor techniques, such as, lower substrate temperature, microstructural control, and very low contamination levels. Film thickness can be controlled from near atomic to micron dimensions. A layer-by-layer (two dimensional) growth can be achieved, resulting in nonequilibrium structures. The films were analyzed using cross-section and high resolution transmission electron microscopy (TEM). The significant reduction in substrate temperature for the formation of high quality multilayer and epitaxial films opens up many new areas of applications requiring reduced thermal-budget processing. The authors present results of sequential deposition of multilayered thin films of carbon and tungsten, titanium nitride and carbide, and high Tc superconductor compounds

  19. Compact electron-beam source for formation of neutral beams of very low vapor pressure materials

    Science.gov (United States)

    Rutherford, J. A.; Vroom, D. A.

    1978-01-01

    In order to form metal vapors for neutral beam studies, an electron-beam heater and a power supply have been designed. The source, which measures about 30 x 50 x 70 mm, consists of a filament, accelerating plate (defined by pole pieces), and a supported target. The electrons from the filament are focused by the field penetration through a 2 mm slit in the high-voltage cage. They are then accelerated to about 5 kV to a ground plate. The electrons then follow a path in the magnetic field and strike the sample to be heated on its front surface. The assembly is attached to a water-cooled base plate. The electron beam source has produced beams of Ta and C particles with densities of about 10 to the 8th power/cu cm.

  20. Ion beam induced conductivity in chemically vapor deposited diamond films

    International Nuclear Information System (INIS)

    Polycrystalline diamond films deposited by the microwave plasma chemical vapor deposition (CVD) technique onto quartz substrates have been irradiated with 100 keV C and 320 keV Xe ions at room temperature and at 200 degree C. The dose dependence of the electrical conductivity measured in situ exhibited complicated, nonmonotonic behavior. High doses were found to induce an increase of up to ten orders of magnitude in the electrical conductivity of the film. The dose dependence of the conductivity for the CVD films was found to be very similar to that measured for natural, type IIa, single-crystal diamonds irradiated under identical conditions. This result suggests that the conduction mechanism in ion beam irradiated polycrystalline CVD diamond films is not dominated by grain boundaries and graphitic impurities as one might have expected, but rather is determined by the intrinsic properties of diamond itself

  1. Theoretical and Experimental Beam Plasma Physics (TEBPP)

    Science.gov (United States)

    Roberts, B.

    1986-01-01

    The theoretical and experimental beam plasma physics (TEBPP) consists of a package of five instruments to measure electric and magnetic fields, plasma density and temperature, neutral density, photometric emissions, and energetic particle spectra during firings of the particle injector (SEPAC) electron beam. The package is developed on a maneuverable boom (or RMS) and is used to measure beam characteristics and induced perturbations field ( 10 m) and mid field ( 10 m to 100 m) along the electron beam. The TEBPP package will be designed to investigate induced oscillations and induced electromagnetic mode waves, neutral and ion density and temperature effects, and beam characteristics as a function of axial distance.

  2. Physics with colliding hadron beams

    CERN Document Server

    Wetherell, Alan M

    1972-01-01

    The results on p-p collisions obtained with the CERN ISR will be reviewed and the current experimental programme described. Future possibilities for colliding hadron beams, other than proton-proton, will be briefly discussed. (0 refs).

  3. Group velocity delay spectroscopy technique for industrial monitoring of electron beam induced vapors

    Energy Technology Data Exchange (ETDEWEB)

    Benterou, J J; Berzins, L V; Sharma, M N

    1998-09-24

    Spectroscopic techniques are ideal for characterization and process control of electron beam generated vapor plumes. Absorption based techniques work well for a wide variety of applications, but are difficult to apply to optically dense or opaque vapor plumes. We describe an approach for monitoring optically dense vapor plumes that is based on measuring the group velocity delay of a laser beam near an optical transition to determine the vapor density. This technique has a larger dynamic range than absorption spectroscopy. We describe our progress towards a robust system to monitor aluminum vaporization in an industrial environment. Aluminum was chosen because of its prevalence in high performance aircraft alloys. In these applications, composition control of the alloy constituents is critical to the deposition process. Data is presented demonstrating the superior dynamic range of the measurement. In addition, preliminary data demonstrating aluminum vapor rate control in an electron beam evaporator is presented. Alternative applications where this technique could be useful are discussed. Keywords: Group velocity delay spectroscopy, optical beat signal, optical heterodyne, index of refraction, laser absorption spectroscopy, external cavity diode laser (ECDL), electron beam vaporization, vapor density, vapor phase manufacturing, process control

  4. Analytical And Numerical Methods In Beam Physics

    CERN Document Server

    Andrianov, S

    2004-01-01

    This report is devoted to discussion of numerical and symbolic computing ratio beam physics. We tray to draw attention on basic conceptual and computational problems first of all. It is known that the main problem in modern computational beam physics connected with high performance computing realization. The most of used approaches are not appropriate for computing using multiprocessing systems. Here we give some possible solutions, which based on symbolic presentation of necessary information and modern information technologies.

  5. Reactive ionized physical vapor deposition of thin films

    OpenAIRE

    Konstantinidis, S.; Snyders, R.

    2011-01-01

    Abstract In this article, the experimental results obtained in our laboratory for the last 10 years and related to the reactive Ionized Physical Vapor Deposition (IPVD) processes are reviewed. Titanium oxide and titanium nitride thin films were chosen as case studies. The titanium-based thin films were synthesized from a pure titanium target sputtered in a mixture of argon and reactive gas (oxygen or nitrogen). Two IPVD processes were investigated namely (i) reactive magnetron sput...

  6. Plasma Spray-Physical Vapor Deposition (PS-PVD) of Ceramics for Protective Coatings

    Science.gov (United States)

    Harder, Bryan J.; Zhu, Dongming

    2011-01-01

    In order to generate advanced multilayer thermal and environmental protection systems, a new deposition process is needed to bridge the gap between conventional plasma spray, which produces relatively thick coatings on the order of 125-250 microns, and conventional vapor phase processes such as electron beam physical vapor deposition (EB-PVD) which are limited by relatively slow deposition rates, high investment costs, and coating material vapor pressure requirements. The use of Plasma Spray - Physical Vapor Deposition (PS-PVD) processing fills this gap and allows thin (< 10 microns) single layers to be deposited and multilayer coatings of less than 100 microns to be generated with the flexibility to tailor microstructures by changing processing conditions. Coatings of yttria-stabilized zirconia (YSZ) were applied to NiCrAlY bond coated superalloy substrates using the PS-PVD coater at NASA Glenn Research Center. A design-of-experiments was used to examine the effects of process variables (Ar/He plasma gas ratio, the total plasma gas flow, and the torch current) on chamber pressure and torch power. Coating thickness, phase and microstructure were evaluated for each set of deposition conditions. Low chamber pressures and high power were shown to increase coating thickness and create columnar-like structures. Likewise, high chamber pressures and low power had lower growth rates, but resulted in flatter, more homogeneous layers

  7. Center for Beam Physics papers

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, A.M. [ed.

    1996-06-01

    Six papers are included in this collection. They cover: a second interaction region for gamma-gamma, gamma-electron and electron- electron collisions; constraints on laser-driven accelerators for a high-energy linear collider; progress on the design of a high luminosity muon-muon collider; RF power source development at the RTA test facility; sensitivity studies of crystalline beams; and single bunch collective effects in muon colliders.

  8. Description of a laser vaporization source and a supersonic cluster beam apparatus

    International Nuclear Information System (INIS)

    Laser vaporization of an appropriate target and recent developments in molecular beam technology have now made it possible to produce supersonic cluster beams of virtually any element in the periodic table. This paper describes the design and principles of a cluster source combined with a time of flight mass spectrometer built for reaction experiments and spectroscopic investigations at Stockholm University

  9. Center for beam physics 1996-1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The Center for Beam Physics (CBP) is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Ernest Orlando Lawrence Berkeley National Laboratory of the University of California. At the heart of the Center`s mission is the fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Special features of the Center`s program include addressing R&D issues needing long development time and providing a platform for conception, initiation, and support of institutional projects based on beams. The Center brings to bear a significant amount of diverse, complementary, and self-sufficient expertise in accelerator physics, synchrotron radiation, advanced microwave techniques, plasma physics, optics, and lasers on the forefront R&D issues in particle and photon beam research. In addition to functioning as a clearinghouse for novel ideas and concepts and related R&D (e.g., various theoretical and experimental studies in beam physics such as nonlinear dynamics, phase space control, laser-beam-plasma interaction, free-electron lasers, optics, and instrumentation), the Center provides significant support to Laboratory facilities and initiatives. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP`s outstanding team and gives a flavor of their multifaceted activities during 1996 and 1997.

  10. Center for beam physics 1996-1997

    International Nuclear Information System (INIS)

    The Center for Beam Physics (CBP) is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Ernest Orlando Lawrence Berkeley National Laboratory of the University of California. At the heart of the Center's mission is the fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Special features of the Center's program include addressing R ampersand D issues needing long development time and providing a platform for conception, initiation, and support of institutional projects based on beams. The Center brings to bear a significant amount of diverse, complementary, and self-sufficient expertise in accelerator physics, synchrotron radiation, advanced microwave techniques, plasma physics, optics, and lasers on the forefront R ampersand D issues in particle and photon beam research. In addition to functioning as a clearinghouse for novel ideas and concepts and related R ampersand D (e.g., various theoretical and experimental studies in beam physics such as nonlinear dynamics, phase space control, laser-beam-plasma interaction, free-electron lasers, optics, and instrumentation), the Center provides significant support to Laboratory facilities and initiatives. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP's outstanding team and gives a flavor of their multifaceted activities during 1996 and 1997

  11. Physics with Rare Isotope Beams

    Energy Technology Data Exchange (ETDEWEB)

    Segel, Ralph E. [Northwestern University

    2013-11-08

    Using stable and radioactive beams provided by ATLAS nuclear reactions of special interest in astrophysics have been studied with emphasis on breakout from the hot CNO cycle to the rp-process. The masses of nuclear fragments provided by a strong fission source have been measured in order to help trace the path of the r process. 8Li ions produced by the d(7Li,8Li)n reaction have been trapped and the electrons and alphas emitted in the ensuing beta-decay measured. The neutrino directions were therefore determined, which leads to a measurement of the electron-neutrino correlation. The energies and kinematics are such that a sensitive search for any tensor admixture could be performed and an upper limit of 0.6% was placed on any such admixture. Earlier work on the electromagnetic form factors of the proton was extended. Graduate students were active participants in all of these eperiments, which formed the basis for six PhD theses.

  12. Center for Beam Physics: 1994--95

    International Nuclear Information System (INIS)

    The Center for Beam Physics is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Lawrence Berkeley Laboratory of the University of California. At the heart of the Center's mission is a fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Dedicated to exploring the frontiers of particle and photon beam physics, its primary mission is to promote the science and technology of the production, manipulation, storage, and control of systems of charged particles and photons. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP's team and gives a brief review of the multifaceted activities during 1994 and 1995

  13. Center for Beam Physics: 1994--95

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    The Center for Beam Physics is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Lawrence Berkeley Laboratory of the University of California. At the heart of the Center`s mission is a fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Dedicated to exploring the frontiers of particle and photon beam physics, its primary mission is to promote the science and technology of the production, manipulation, storage, and control of systems of charged particles and photons. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP`s team and gives a brief review of the multifaceted activities during 1994 and 1995.

  14. Collimated Blue and Infrared Beams Generated by Two-Photon Excitation in Rubidium Vapor

    Science.gov (United States)

    Gearba, Alina; Sell, Jerry; Olesen, Robert; Knize, Randy

    2016-05-01

    Utilizing nonlinear optical processes in Rb vapor we describe the generation of optical fields at 420 nm, 1.32 μm, and 1.37 μm. Input laser beams at 780 nm and 776 nm enter a heated Rb vapor cell collinear and circularly polarized. Rubidium atoms are excited to the 5D5 / 2 state, with blue light generated by four-wave mixing through the 6P3 / 2 --> 5S1 / 2 states, while infrared beams at 1.37 μm and 1.32 μm are generated by cascading decays through the 6S1 / 2 --> 5P3 / 2 and 6S1 / 2 --> 5P1 / 2 states, respectively. While the blue beam emission from four-wave mixing has been studied in detail, the mechanisms responsible for generating the infrared beams are still under investigation. We will present our results for the conditions which give rise to infrared beam generation by two-photon excitation in rubidium vapor.

  15. Plasma-based physical vapor deposition surface engineering processes

    International Nuclear Information System (INIS)

    Plasma-based physical vapor deposition (PVD) process developments occurring over the past few decades now allow the production of tribological coatings with properties which were previously unachievable. These new coatings will be critical in the creation of new products with improved functionality and performance, which will have a dramatic impact on, for example, their operating efficiency and lifetime. The key pioneers behind these PVD developments are discussed here, together with some significant process innovations. The latter include ionization-enhancing systems, such as thermionic assistance and arc evaporation, as well as unbalanced magnetron sputtering and magnetic plasma confinement. These developments have provided the impetus behind the recent growth in the technology field which we now know as surface engineering, and the recognition that surfaces provide the functionality and durability for almost all engineered products. Vacuum plasma technologies can thus be regarded as critical, not only for functional devices and thin film applications (for which their importance was previously most recognized), but also for structural product applications; they will thus underpin the entire spectrum of manufacturing industry

  16. Quantum physics and the beam splitter mystery

    Science.gov (United States)

    Hénault, François

    2015-09-01

    Optical lossless beam splitters are frequently encountered in fundamental physics experiments regarding the nature of light, including "which-way" determination or the EPR paradox and their measurement apparatus. Although they look as common optical components at first glance, their behaviour remains somewhat mysterious since they apparently exhibit stand-alone particle-like features, and then wave-like characteristics when inserted into a Mach-Zehnder interferometer. In this communication are examined and discussed some basic properties of these beamssplitters, both from a classical optics and quantum physics point of view. Herein the most evident convergences and contradictions are highlighted, and the results of a few emblematic experiments demonstrating photon existence are discussed. Alternative empirical models are also proposed in order to shed light on some remaining issues.

  17. Collimated Blue and Infrared Beams Generated by Two-Photon Excitation in Rb Vapor

    CERN Document Server

    Sell, J F; DePaola, B D; Knize, R J

    2013-01-01

    Utilizing two-photon excitation in hot Rb vapor we demonstrate the generation of collimated optical fields at 420 nm and 1324 nm. Input laser beams at 780 nm and 776 nm enter a heated Rb vapor cell collinear and circularly polarized, driving Rb atoms to the $5D_{5/2}$ state. Under phase-matching conditions coherence among the $5S_{1/2}\\rightarrow 5P_{3/2}\\rightarrow 5D_{5/2} \\rightarrow 6P_{3/2}$ transitions produces a blue (420 nm) beam by four-wave mixing. We also observe a forward and backward propagating IR (1324 nm) beam, due to cascading decays through the $6S_{1/2}\\rightarrow 5P_{1/2}$ states. Power saturation of the generated beams is investigated by scaling the input powers to greater than 200 mW, resulting in a coherent blue beam of 9.1 mW power, almost an order of magnitude larger than previously achieved. We measure the dependences of both beams in relation to the Rb density, the frequency detuning between Rb ground state hyperfine levels, and the input laser intensities.

  18. Important atomic physics issues for ion beam fusion

    International Nuclear Information System (INIS)

    This paper suggests several current atomic physics questions important to ion beam fusion. Among the topics discussed are beam transport, beam-target interaction, and reactor design. The major part of the report is discussion concerning areas of research necessary to better understand beam-target interactions

  19. Electron-beam-directed vapor deposition of multifunctional structures for electrochemical storage

    Science.gov (United States)

    Queheillalt, Douglas T.; Hass, Derek D.; Wadley, Haydn N. G.

    2002-07-01

    Multifunctional structures are those, which combine load- bearing support in addition to additional functions such as mechanical actuation, distributed power supply or thermal management. Electron beam - directed vapor deposition technology has been used to investigate deposition methodologies for two multifunctional battery concepts: a linear/truss base nickel - metal hydride and a fiber based solid-state Li+ ion multifunctional battery. Porous nickel coatings for the cathodes and porous rare earth metal coatings based on La and Ni or Ti and Zr for the anodes are being investigated for the nickel - metal hydride system; where LiV2O5, LiPON, and Sn3N4 are being investigated for the Li+ ion based system. Electron beam - directed vapor deposition is being used for deposition of all cathode/anode structures to provide an economical method for the development of these novel multifunctional structures.

  20. Single-beam water vapor detection system with automatic photoelectric conversion gain control

    Science.gov (United States)

    Zhu, C. G.; Chang, J.; Wang, P. P.; Wang, Q.; Wei, W.; Liu, Z.; Zhang, S. S.

    2014-11-01

    A single-beam optical sensor system with automatic photoelectric conversion gain control is proposed for doing high reliability water vapor detection under relatively rough environmental conditions. Comparing to a dual-beam system, it can distinguish the finer photocurrent variations caused by the optical power drift and provide timely compensation by automatically adjusting the photoelectric conversion gain. This system can be rarely affected by the optical power drift caused by fluctuating ambient temperature or variation of fiber bending loss. The deviation of the single-beam system is below 1.11% when photocurrent decays due to fiber bending loss for bending radius of 5 mm, which is obviously lower than the dual-beam system (8.82%). We also demonstrate the long-term stability of the single-beam system by monitoring a 660 ppm by volume (ppmv) water vapor sample continuously for 24 h. The maximum deviation of the measured concentration during the whole testing period does not exceed 10 ppmv. Experiments have shown that the new system features better reliability and is more apt for remote sensing application which is often subject to light transmission loss.

  1. Physics of zinc vaporization and plasma absorption during CO2 laser welding

    International Nuclear Information System (INIS)

    A number of mathematical models have been developed earlier for single-material laser welding processes considering one-, two-, and three-dimensional heat and mass transfers. However, modeling of laser welding of materials with multiple compositions has been a difficult problem. This paper addresses a specific case of this problem where CO2 laser welding of zinc-coated steel, commonly used in automobile body manufacturing, is mathematically modeled. The physics of a low boiling point material, zinc, is combined with a single-material (steel) welding model, considering multiple physical phenomena such as keyhole formation, capillary and thermocapillary forces, recoil and vapor pressures, etc. The physics of laser beam-plasma interaction is modeled to understand the effect on the quality of laser processing. Also, an adaptive meshing scheme is incorporated in the model for improving the overall computational efficiency. The model, whose results are found to be in close agreement with the experimental observations, can be easily extended for studying zinc-coated steel welding using other high power, continuous wave lasers such as Nd:YAG and Yb:YAG

  2. Vapor chambers for an atmospheric cloud physics laboratory

    Science.gov (United States)

    Fleischman, G. L.; Scollon, T. R., Jr.; Loose, J. D.

    1980-01-01

    The methanol/stainless steel vapor chambers (flat-plate heat pipes) discussed in this paper were developed for use in spaceborne atmospheric cloud chambers. This application imposed stringent thermal and mechanical requirements on the design. Flatness, low thermal mass, vibration, and structural integrity requirements were achieved in addition to precision temperature uniformity and thermal transport. Heat transfer coefficients on the order of 0.34 to 0.40 W/sq cm -C were measured. The vapor chambers are capable of transporting 170 W-cm per cm of width in either the axial or side-to-side direction.

  3. Study of solid oxide fuel cell interconnects, protective coatings and advanced physical vapor deposition techniques

    Science.gov (United States)

    Gannon, Paul Edward

    High energy conversion efficiency, decreased environmentally-sensitive emissions and fuel flexibility have attracted increasing attention toward solid oxide fuel cell (SOFC) systems for stationary, transportation and portable power generation. Critical durability and cost issues, however, continue to impede wide-spread deployment. Many intermediate temperature (600-800°C) planar SOFC systems employ metallic alloy interconnect components, which physically connect individual fuel cells into electric series, facilitate gas distribution to appropriate SOFC electrode chambers (fuel/anode and oxidant[air]/cathode) and provide SOFC stack mechanical support. These demanding multifunctional requirements challenge commercially-available and inexpensive metallic alloys due to corrosion and related effects. Many ongoing investigations are aimed at enabling inexpensive metallic alloys (via bulk and/or surface modifications) as SOFC interconnects (SOFC(IC)s). In this study, two advanced physical vapor deposition (PVD) techniques: large area filtered vacuum arc deposition (LAFAD), and filtered arc plasma-assisted electron beam PVD (FA-EBPVD) were used to deposit a wide-variety of protective nanocomposite (amorphous/nanocrystalline) ceramic thin-film (1,000 hours); and, dramatically reduced Cr volatility (>30-fold). Analyses and discussions of SOFC(IC) corrosion, advanced PVD processes and protective coating behavior are intended to advance understanding and accelerate the development of durable and commercially-viable SOFC systems.

  4. Beam Polarization at the ILC: Physics Case and Realization

    Science.gov (United States)

    Vauth, Annika; List, Jenny

    2016-02-01

    The International Linear Collider (ILC) is a proposed e+e‑ collider, focused on precision measurement of the Standard Model and new physics beyond. Polarized beams are a key element of the ILC physics program. The physics studies are accompanied by an extensive R&D program for the creation of the polarized beams and the measurement of their polarization. This contribution will review the advantages of using beam polarization and its technical aspects and realization, such as the creation of polarized beams and the measurement of the polarization.

  5. Proposal of physics with exotic beams at Oak Ridge

    International Nuclear Information System (INIS)

    A facility to produce proton-rich radioactive beams for nuclear structure and astrophysics experiments is proposed. This Oak Ridge Exotic Beam (OREB) facility is based on two existing accelerators. Beams of mass up to 80 can be accelerated to energies of about 5 MeV/nucleon. It will provide opportunities to study new areas in nuclear physics and astrophysics that are not available with the use of stable beams. 3 figs

  6. Diode Pumped Alkali Vapor Lasers - A New Pathway to High Beam Quality at High Average Power

    Energy Technology Data Exchange (ETDEWEB)

    Page, R H; Boley, C D; Rubenchik, A M; Beach, R J

    2005-05-06

    Resonance-transition alkali-vapor lasers have only recently been demonstrated [1] but are already attracting considerable attention. Alkali-atom-vapor gain media are among the simplest possible systems known, so there is much laboratory data upon which to base performance predictions. Therefore, accurate modeling is possible, as shown by the zero- free-parameter fits [2] to experimental data on alkali-vapor lasers pumped with Ti:sapphire lasers. The practical advantages of two of the alkali systems--Rb and Cs--are enormous, since they are amenable to diode-pumping [3,4]. Even without circulating the gas mixture, these lasers can have adequate cooling built-in owing to the presence of He in their vapor cells. The high predicted (up to 70%) optical-to-optical efficiency of the alkali laser, the superb (potentially 70% or better) wall-plug efficiency of the diode pumps, and the ability to exhaust heat at high temperature (100 C) combine to give a power-scalable architecture that is lightweight. A recent design exercise [5] at LLNL estimated that the system ''weight-to-power ratio'' figure of merit could be on the order of 7 kg/kW, an unprecedented value for a laser of the 100 kW class. Beam quality is expected to be excellent, owing to the small dn/dT value of the gain medium. There is obviously a long way to go, to get from a small laser pumped with a Ti:sapphire or injection-seeded diode system (of near-perfect beam quality, and narrow linewidth) [1, 4] to a large system pumped with broadband, multimode diode- laser arrays. We have a vision for this technology-development program, and have already built diode-array-pumped Rb lasers at the 1 Watt level. A setup for demonstrating Diode-array-Pumped Alkali vapor Lasers (DPALs) is shown in Figure 1. In general, use of a highly-multimode, broadband pump source renders diode-array-based experiments much more difficult than the previous ones done with Ti:sapphire pumping. High-NA optics, short focal

  7. Hybrid Physical-Chemical Vapor Deposition of Bi2Se3 Thin films on Sapphire

    Science.gov (United States)

    Brom, Joseph; Ke, Yue; Du, Renzhong; Gagnon, Jarod; Li, Qi; Redwing, Joan

    2012-02-01

    High quality thin films of topological insulators continue to garner much interest. We report on the growth of highly-oriented thin films of Bi2Se3 on c-plane sapphire using hybrid physical-chemical vapor deposition (HPCVD). The HPCVD process utilizes the thermal decomposition of trimethyl bismuth (TMBi) and evaporation of elemental selenium in a hydrogen ambient to deposit Bi2Se3. Growth parameters including TMBi flow rate and decomposition temperature and selenium evaporation temperature were optimized, effectively changing the Bi:Se ratio, to produce high quality films. Glancing angle x- ray diffraction measurements revealed that the films were c-axis oriented on sapphire. Trigonal crystal planes were observed in atomic force microscopy images with an RMS surface roughness of 1.24 nm over an area of 2μmx2μm. Variable temperature Hall effect measurements were also carried out on films that were nominally 50-70 nm thick. Over the temperature range from 300K down to 4.2K, the carrier concentration remained constant at approximately 6x10^18 cm-3 while the mobility increased from 480 cm^2/Vs to 900 cm^2/Vs. These results demonstrate that the HPCVD technique can be used to deposit Bi2Se3 films with structural and electrical properties comparable to films produced by molecular beam epitaxy.

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

    International Nuclear Information System (INIS)

    We have grown graphene by chemical vapor deposition (CVD) and transferred it onto Si/SiO2 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/cm2) 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.

  9. Electron beams: Physical and clinical aspects

    International Nuclear Information System (INIS)

    Megavoltage electron beams represent an important treatment modality in modern radiotherapy, often providing a unique option in the treatment of superficial tumours (less than 5 cm deep). Electrons have been used in radiotherapy since the early 1950s, first produced by betatrons and then by microtrons and linacs. Modern high energy linacs typically provide, in addition to two megavoltage photon energies, several electron beam energies in the range from 4 to 22 MeV

  10. Plasma and Ion Assistance in Physical Vapor Deposition: AHistorical Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2007-02-28

    Deposition of films using plasma or plasma-assist can betraced back surprisingly far, namely to the 18th century for arcs and tothe 19th century for sputtering. However, only since the 1960s thecoatings community considered other processes than evaporation for largescale commercial use. Ion Plating was perhaps the first importantprocess, introducing vapor ionization and substrate bias to generate abeam of ions arriving on the surface of the growing film. Ratherindependently, cathodic arc deposition was established as an energeticcondensation process, first in the former Soviet Union in the 1970s, andin the 1980s in the Western Hemisphere. About a dozen various ion-basedcoating technologies evolved in the last decades, all characterized byspecific plasma or ion generation processes. Gridded and gridless ionsources were taken from space propulsion and applied to thin filmdeposition. Modeling and simulation have helped to make plasma and ionseffects to be reasonably well understood. Yet--due to the complex, oftennon-linear and non-equilibrium nature of plasma and surfaceinteractions--there is still a place for the experience plasma"sourcerer."

  11. Effect of melt surface depression on the vaporization rate of a metal heated by an electron beam

    International Nuclear Information System (INIS)

    In order to produce high density vapor, a metal confined in a water cooled crucible is heated by an electron beam (eb). The energy transfer to the metal causes partial melting, forming a pool where the flow is driven by temperature induced buoyancy and capillary forces. Furthermore, when the vaporization rate is high, the free surface is depressed by the thrust of the vapor. The main objective of this paper is to analyse the combined effects of liquid flow and vapor condensation back on the liquid surface. This is done with TRIO-EF, a general purpose fluid mechanics finite element code. A suitable iterative scheme is used to calculate the free surface flow and the temperature field. The numerical simulation gives an insight about the influence of the free surface in heat transfer. The depression of the free surface induces strong effects on both liquid and vapor. As liquid is concerned, buoyancy convection in the pool is enhanced, the energy flux from electron beam is spread and constriction of heat flux under the eb spot is weakened. It results that heat transfer towards the crucible is reinforced. As vapor is concerned, its fraction that condenses back on the liquid surface is increased. These phenomena lead to a saturation of the net vaporization rate as the eb spot radius is reduced, at constant eb power. (author). 8 refs., 13 figs., 2 tabs

  12. Ion-beam-induced epitaxial crystallization of implanted and chemical vapor deposited amorphous silicon

    Science.gov (United States)

    La Ferla, A.; Priolo, F.; Spinella, C.; Rimini, E.; Baroetto, F.; Ferla, G.

    1989-03-01

    The dependence of ion-beam enhanced epitaxial growth of amorphous Si layers on impurities either dissolved in the film or present at the film-substrate interface is considered. In the case of ion implanted layers, electrically active dopants, like B, P, As at concentrations above 1 × 10 20/cm 3, enhance the rate by a factor of 2 with respect to the undoped layer. The enhancement shows also a weak dependence on the dopant concentration. Inert impurities, like Ar, which prevent pure thermal regrowth, do not show any appreciable influence on the ion-beam-induced growth rate. Chemical vapor deposited Si layers with a thin native interfacial oxide layer can also be epitaxially regrown under ion irradiation. A critical fluence is needed before the interfacial oxide breaks down and broadens, allowing the epitaxial crystallization to take place. This process is characterized by an activation energy of 0.44 eV. The complex phenomenon of ion-beam-induced crystallization involves a dynamical interaction between production and annealing of point defects. The presence of electrically active dopants probably influences the lifetime of point defects. Impurities which prevent thermal regrowth are instead dissolved by ballistic effects and/or radiation-enhanced mixing.

  13. Plasma and Ion Assistance in Physical Vapor Deposition: A Historical Perspective

    OpenAIRE

    Anders, Andre

    2007-01-01

    Deposition of films using plasma or plasma-assist can be traced back surprisingly far, namely to the 18th century for arcs and to the 19th century for sputtering. However, only since the 1960s the coatings community considered other processes than evaporation for large scale commercial use. Ion Plating was perhaps the first important process, introducing vapor ionization and substrate bias to generate a beam of ions arriving on the surface of the growing film. Rather independently, catho...

  14. PHYSICAL VAPOR DEPOSITION OF TANTALUM ON GUN BARREL STEEL (SYSTEMS ANLAYSIS BRANCH, SUSTAINABLE TECHNOLOGY DIVISION, NRMRL)

    Science.gov (United States)

    This project entails the development of an alternative technology for plating gun barrel steel to replace the process electroplating of chrome (Cr-electroplate) with physical vapor deposition of tantalum (Ta-PVD). Developed by Benet Laboratory at Watervliet Arsenal, this project'...

  15. Relationship between 578-nm (copper vapor) laser beam geometry and heat distribution within biological tissues

    Science.gov (United States)

    Ilyasov, Ildar K.; Prikhodko, Constantin V.; Nevorotin, Alexey J.

    1995-01-01

    Monte Carlo (MC) simulation model and the thermoindicative tissue phantom were applied for evaluation of a depth of tissue necrosis (DTN) as a result of quasi-cw copper vapor laser (578 nm) irradiation. It has been shown that incident light focusing angle is essential for DTN. In particular, there was a significant rise in DTN parallel to elevation of this angle up to +20 degree(s)C and +5 degree(s)C for both the MC simulation and tissue phantom models, respectively, with no further increase in the necrosis depth above these angles. It is to be noted that the relationship between focusing angles and DTN values was apparently stronger for the real target compared to the MC-derived hypothetical one. To what extent these date are applicable for medical practice can be evaluated in animal models which would simulate laser-assisted therapy for PWS or related dermatologic lesions with converged 578 nm laser beams.

  16. Essay: Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    International Nuclear Information System (INIS)

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  17. Physics with polarized beams: experimental review

    International Nuclear Information System (INIS)

    In high energy physics, discussion of spin effects generally involves proton--proton scattering, that being the area where the best experiments could be performed. Several such experiments are reviewed

  18. Precision atomic physics techniques for nuclear physics with radioactive beams

    OpenAIRE

    Blaum, Klaus; Dilling, Jens; Nörtershäuser, Wilfried

    2013-01-01

    Atomic physics techniques for the determination of ground-state properties of radioactive isotopes are very sensitive and provide accurate masses, binding energies, Q-values, charge radii, spins, and electromagnetic moments. Many fields in nuclear physics benefit from these highly accurate numbers. They give insight into details of the nuclear structure for a better understanding of the underlying effective interactions, provide important input for studies of fundamental symmetries in physics...

  19. Realistic physics perspectives using radioactive beams from SPIRAL at GANIL

    International Nuclear Information System (INIS)

    The majority of the large international community in nuclear physics is looking towards the use of radioactive ion beams to broaden the horizon of our understanding of the physics of the nucleus. In theory, the use of radioactive beams will open a new era in nuclear physics by allowing access to new isotopes and by increasing the production rates of nuclei which can presently only be populated with extremely low cross-sections or not at all. However the beam intensities as well as the rather low variety of accelerated species will be constraints at least at the start up of the new facilities. A realistic physics program at SPIRAL is described as well as the necessary experimental tools. These essentially consist in two major devices built in the framework of large european collaborations: the VAMOS spectrometer and the EXOGAM γ-ray array. (author)

  20. The Physics of Beams: The Andrew Sessler Symposium

    International Nuclear Information System (INIS)

    These proceedings represent papers presented at the Andrew Sessler Symposium held at the Lawrence Berkeley National Laboratory in honor of Andrew Sessler close-quote s over forty years of major scientific contributions to accelerator and beam physics as well as in celebration of his 65th birthday. The symposium was sponsored by the United States Department of Energy. The topics discussed include linear colliders, past history and future speculations, ELOISATRON at 100 TeV beam, manipulating charged particle beams by means of plasma and collective instabilities in accelerator and storage rings. There were 10 papers presented and 8 have been abstracted for the Energy Science and Technology database

  1. Physical meaning of supersonic molecular beams

    International Nuclear Information System (INIS)

    In this report a generic steady isentropic flow is firstly considered and the flow variables are expressed as functions of the Mach number and of the stagnation parameters. Then, the physical meaning of the characteristic lines is pointed out and the compression, shock and expansion waves are analysed in terms of such lines. The concept of characteristic is also introduced from a purely mathematical point of view. Furthermore, the cases of a uniform planar flow with a small perturbation and of a planar flow near curved walls are analysed

  2. Workshop on Physics with Neutral Kaon Beam at JLab

    CERN Document Server

    Chudakov, E.; Meyer, C.; Pennington, M.; Ritman, J.; Strakovsky, I.; KL2016

    2016-01-01

    The KL2016 Workshop is following the Letter of Intent LoI12-15-001 "Physics Opportunities with Secondary KL beam at JLab" submitted to PAC43 with the main focus on the physics of excited hyperons produced by the Kaon beam on unpolarized and polarized targets with GlueX setup in Hall D. Such studies will broaden a physics program of hadron spectroscopy extending it to the strange sector. The Workshop was organized to get a feedback from the community to strengthen physics motivation of the LoI and prepare a full proposal. Further details about the Workshop can be found on the web page of the conference: http://www.jlab.org/conferences/kl2016/index.html .

  3. Two Types of Mass Abundance Distributions for Anionic Carbon Clusters Investigated by Laser Vaporization and Pulsed Molecular Beam Techniques

    Institute of Scientific and Technical Information of China (English)

    ZHAI Hua-Jin; LIU Bing-Chen; NI Guo-Quan; XUZhi-Zhan

    2000-01-01

    Two types of mass spectra for anionic carbon clusters Cn- have been revealed using laser vaporization and pulsed molecular beam techniques. The less structured mass spectrum characteristic of the magic-numbers at n = 5, 8,11, 15, and 17 is established at the early stage of the cluster formation process, namely, in the laser vaporization process. The more structured one is featured for a regular odd-even alternation and the magic numbers at n =10, 12, 16, 18, 22, and 28, and has been developed only after extensive clustering and qnenching processes, where low-energy electron attachment plays a vital role. Transition between these two types of mass spectra can be realized by controlling either the strength of the pulsed gas flow or the synchronism between the gas flow and the laser vaporization.

  4. Advances in beam physics and technology: Colliders of the future

    International Nuclear Information System (INIS)

    Beams may be viewed as directed and focussed flow of energy and information, carried by particles and electromagnetic radiation fields (ie, photons). Often, they interact with each other (eg, in high energy colliders) or with other forms of matter (eg, in fixed targets, sychrotron radiation, neutron scattering, laser chemistry/physics, medical therapy, etc.). The whole art and science of beams revolve around the fundamental quest for, and ultimate implementation of, mechanisms of production, storage, control and observation of beams -- always directed towards studies of the basic structures and processes of the natural world and various practical applications. Tremendous progress has been made in all aspects of beam physics and technology in the last decades -- nonlinear dynamics, superconducting magnets and rf cavities, beam instrumentation and control, novel concepts and collider praradigms, to name a few. We illustrate this progress with a few examples and remark on the emergence of new collider scenarios where some of these progress might come to use -- the Gamma-Gamma Collider, the Muon Collider, laser acceleration, etc. We close with an outline of future oppotunities and outlook

  5. Proceedings of workshop on physics with polarized beam

    International Nuclear Information System (INIS)

    The small meeting on the construction of the 12 GeV polarized proton beam facility was held at National Laboratory for High Energy Physics on December 7, 1984. At this meeting, the present status of the construction of the polarized beam facility, the feasibility of some experiments by the polarized proton and the topical suggestions from the theoretical aspect were reported and discussed. Moreover, the advanced study on the polarized photon and electron sources, and the activities at the foreign institutes, such as Los Alamos National Laboratory, were also introduced. (Nogami, K.)

  6. Intense Ion Beam for Warm Dense Matter Physics

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Joshua Eugene

    2008-05-23

    The Neutralized Drift Compression Experiment (NDCX) at Lawrence Berkeley National Laboratory is exploring the physical limits of compression and focusing of ion beams for heating material to warm dense matter (WDM) and fusion ignition conditions. The NDCX is a beam transport experiment with several components at a scale comparable to an inertial fusion energy driver. The NDCX is an accelerator which consists of a low-emittance ion source, high-current injector, solenoid matching section, induction bunching module, beam neutralization section, and final focusing system. The principal objectives of the experiment are to control the beam envelope, demonstrate effective neutralization of the beam space-charge, control the velocity tilt on the beam, and understand defocusing effects, field imperfections, and limitations on peak intensity such as emittance and aberrations. Target heating experiments with space-charge dominated ion beams require simultaneous longitudinal bunching and transverse focusing. A four-solenoid lattice is used to tune the beam envelope to the necessary focusing conditions before entering the induction bunching module. The induction bunching module provides a head-to-tail velocity ramp necessary to achieve peak axial compression at the desired focal plane. Downstream of the induction gap a plasma column neutralizes the beam space charge so only emittance limits the focused beam intensity. We present results of beam transport through a solenoid matching section and simultaneous focusing of a singly charged K{sup +} ion bunch at an ion energy of 0.3 MeV. The results include a qualitative comparison of experimental and calculated results after the solenoid matching section, which include time resolved current density, transverse distributions, and phase-space of the beam at different diagnostic planes. Electron cloud and gas measurements in the solenoid lattice and in the vicinity of intercepting diagnostics are also presented. Finally, comparisons

  7. Intense Ion Beams for Warm Dense Matter Physics

    International Nuclear Information System (INIS)

    The Neutralized Drift Compression Experiment (NDCX) at Lawrence Berkeley National Laboratory is exploring the physical limits of compression and focusing of ion beams for heating material to warm dense matter (WDM) and fusion ignition conditions. The NDCX is a beam transport experiment with several components at a scale comparable to an inertial fusion energy driver. The NDCX is an accelerator which consists of a low-emittance ion source, high-current injector, solenoid matching section, induction bunching module, beam neutralization section, and final focusing system. The principal objectives of the experiment are to control the beam envelope, demonstrate effective neutralization of the beam space-charge, control the velocity tilt on the beam, and understand defocusing effects, field imperfections, and limitations on peak intensity such as emittance and aberrations. Target heating experiments with space-charge dominated ion beams require simultaneous longitudinal bunching and transverse focusing. A four-solenoid lattice is used to tune the beam envelope to the necessary focusing conditions before entering the induction bunching module. The induction bunching module provides a head-to-tail velocity ramp necessary to achieve peak axial compression at the desired focal plane. Downstream of the induction gap a plasma column neutralizes the beam space charge so only emittance limits the focused beam intensity. We present results of beam transport through a solenoid matching section and simultaneous focusing of a singly charged K+ ion bunch at an ion energy of 0.3 MeV. The results include a qualitative comparison of experimental and calculated results after the solenoid matching section, which include time resolved current density, transverse distributions, and phase-space of the beam at different diagnostic planes. Electron cloud and gas measurements in the solenoid lattice and in the vicinity of intercepting diagnostics are also presented. Finally, comparisons of

  8. Effects of buoyancy-driven flow and thermal boundary conditions on physical vapor transport

    Science.gov (United States)

    Nadarajah, Arunan; Rosenberger, Franz; Alexander, J. I. D.

    1992-01-01

    A 2D numerical model was developed in order to ascertain if reduced gravity conditions are beneficial to physical vapor transport (PVT) and to determine its tolerance limits to residual accelerations. This was solved using the PHOENICS finite-volume code. Reduction of gravitational accelerations to less than 0.1 g0 was found to be sufficient to suppress buoyancy-driven convection to an extent that diffusion was the dominant transport mode, whence a greater uniformity in the growth rate could be obtained. It is shown that a uniform temperature gradient on the ampoule walls causes the vapor to be supersaturated throughout the ampoule, potentially resulting in undesirable nucleation at the walls. A 'hump' in the wall temperature profile can be used to avoid this. The prevailing transport conditions determine the size of the hump needed.

  9. MgB{sub 2} thin films by hybrid physical-chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xi, X.X. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]. E-mail: xxx4@psu.edu; Pogrebnyakov, A.V. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Xu, S.Y.; Chen, K.; Cui, Y.; Maertz, E.C. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Zhuang, C.G. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Physics, Peking University, Beijing 100871 (China); Li, Qi [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Lamborn, D.R. [Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Redwing, J.M. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Liu, Z.K.; Soukiassian, A.; Schlom, D.G.; Weng, X.J.; Dickey, E.C. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Chen, Y.B.; Tian, W.; Pan, X.Q. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Cybart, S.A. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Dynes, R.C. [Department of Physics, University of California, Berkeley, CA 94720 (United States)

    2007-06-01

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB{sub 2} thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB{sub 2} films. The epitaxial pure MgB{sub 2} films grown by HPCVD show higher-than-bulk T {sub c} due to tensile strain in the films. The HPCVD films are the cleanest MgB{sub 2} materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB{sub 2}. The carbon-alloyed HPCVD films demonstrate record-high H {sub c2} values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB{sub 2} Josephson junctions.

  10. MgB 2 thin films by hybrid physical-chemical vapor deposition

    Science.gov (United States)

    Xi, X. X.; Pogrebnyakov, A. V.; Xu, S. Y.; Chen, K.; Cui, Y.; Maertz, E. C.; Zhuang, C. G.; Li, Qi; Lamborn, D. R.; Redwing, J. M.; Liu, Z. K.; Soukiassian, A.; Schlom, D. G.; Weng, X. J.; Dickey, E. C.; Chen, Y. B.; Tian, W.; Pan, X. Q.; Cybart, S. A.; Dynes, R. C.

    2007-06-01

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB 2 thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB 2 films. The epitaxial pure MgB 2 films grown by HPCVD show higher-than-bulk Tc due to tensile strain in the films. The HPCVD films are the cleanest MgB 2 materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB 2. The carbon-alloyed HPCVD films demonstrate record-high Hc2 values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB 2 Josephson junctions.

  11. MgB2 thin films by hybrid physical-chemical vapor deposition

    International Nuclear Information System (INIS)

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB2 thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB2 films. The epitaxial pure MgB2 films grown by HPCVD show higher-than-bulk T c due to tensile strain in the films. The HPCVD films are the cleanest MgB2 materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB2. The carbon-alloyed HPCVD films demonstrate record-high H c2 values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB2 Josephson junctions

  12. Investigation of physical vapor deposition techniques of conformal shell coating for core/shell structures by Monte Carlo simulations

    International Nuclear Information System (INIS)

    Vertically aligned core/shell nanowire (nanorod) arrays are favorable candidates in many nano-scale devices such as solar cells, detectors, and integrated circuits. The quality of the shell coating around nanowire arrays is as crucial as the quality of the nanowires in device applications. For this reason, we worked on different physical vapor deposition (PVD) techniques and conducted Monte Carlo simulations to estimate the best deposition technique for a conformal shell coating. Our results show that a small angle (≤ 45°) between incoming flux of particles and the substrate surface normal is necessary for PVD techniques with a directional incoming flux (e.g. thermal or e-beam evaporation) for a reasonable conformal coating. On the other hand, PVD techniques with an angular flux distribution (e.g. sputtering) can provide a fairly conformal shell coating around nanowire arrays without a need of small angle deposition. We also studied the shape effect of the arrays on the conformality of the coating and discovered that arrays of the tapered-top nanorods and the pyramids can be coated with a more conformal and thicker coating compared to the coating on the arrays of flat-top nanowires due to their larger openings in between structures. Our results indicate that conventional PVD techniques, which offer low cost and large scale thin film fabrication, can be utilized for highly conformal and uniform shell coating formation in core/shell nanowire device applications. - Highlights: • We examined the shell coating growth in core/shell nanostructures. • We investigated the effect of physical vapor deposition method on the conformality of the shell. • We used Monte Carlo simulations to simulate the shell growth on nanowire templates. • Angular atomic flux (i.e., sputtering at high pressure) leads to conformal and uniform coatings. • A small angle (< 45°) to the directional flux needs to be introduced for conformal coatings

  13. Investigation of physical vapor deposition techniques of conformal shell coating for core/shell structures by Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Cansizoglu, H., E-mail: hxis@ualr.edu; Yurukcu, M.; Cansizoglu, M.F.; Karabacak, T.

    2015-05-29

    Vertically aligned core/shell nanowire (nanorod) arrays are favorable candidates in many nano-scale devices such as solar cells, detectors, and integrated circuits. The quality of the shell coating around nanowire arrays is as crucial as the quality of the nanowires in device applications. For this reason, we worked on different physical vapor deposition (PVD) techniques and conducted Monte Carlo simulations to estimate the best deposition technique for a conformal shell coating. Our results show that a small angle (≤ 45°) between incoming flux of particles and the substrate surface normal is necessary for PVD techniques with a directional incoming flux (e.g. thermal or e-beam evaporation) for a reasonable conformal coating. On the other hand, PVD techniques with an angular flux distribution (e.g. sputtering) can provide a fairly conformal shell coating around nanowire arrays without a need of small angle deposition. We also studied the shape effect of the arrays on the conformality of the coating and discovered that arrays of the tapered-top nanorods and the pyramids can be coated with a more conformal and thicker coating compared to the coating on the arrays of flat-top nanowires due to their larger openings in between structures. Our results indicate that conventional PVD techniques, which offer low cost and large scale thin film fabrication, can be utilized for highly conformal and uniform shell coating formation in core/shell nanowire device applications. - Highlights: • We examined the shell coating growth in core/shell nanostructures. • We investigated the effect of physical vapor deposition method on the conformality of the shell. • We used Monte Carlo simulations to simulate the shell growth on nanowire templates. • Angular atomic flux (i.e., sputtering at high pressure) leads to conformal and uniform coatings. • A small angle (< 45°) to the directional flux needs to be introduced for conformal coatings.

  14. A comparison of the physics of Gas Tungsten Arc Welding (GTAW), Electron Beam Welding (EBW), and Laser Beam Welding (LBW)

    Science.gov (United States)

    Nunes, A. C., Jr.

    1985-01-01

    The physics governing the applicability and limitations of gas tungsten arc (GTA), electron beam (EB), and laser beam (LB) welding are compared. An appendix on the selection of laser welding systems is included.

  15. Physics with primary beams of the KEK-PS

    International Nuclear Information System (INIS)

    The 12-GeV Proton Synchrotron (PS) at the National Laboratory for High Energy Physics (KEK) has provided great opportunities to high-energy-physics and related communities as a unique high-energy hadron machine, since its operation in 1976. Activities of the KEK-PS are indispensable for the rapid development in the field. Six experimental subjects are proposed in this Report; (1) media effects in φ meson decay, (2) multifragmentation in high-energy reactions, (3) mechanism of high-energy reactions by means of radio-chemical methods, (4) physics with polarized high-energy neutrons, (5) physics with polarized high-energy deuterons, and (6) hypernucleus with high-energy heavy-ion beams. As a summary, new facilities (a new injector, a new beamline and a new experimental area) and physics programs with primary beams, proposed in this Report are themselves unique and valuable. Moreover, technical developments and physics outcomes stimulated with those new facilities are indispensable for future plans of the KEK-PS. (J.P.N.)

  16. The COMPASS Setup for Physics with Hadron Beams

    CERN Document Server

    Abbon, Ph.; Akhunzyanov, R.; Alexandrov, Yu.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Burtin, E.; Capozza, L.; Ciliberti, P.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Cotte, D.; Crespo, M.L.; Curiel, Q.; Dafni, T.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Desforge, D.; Dinkelbach, A.M.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Durand, D.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Gatignon, L.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Geyer, R.; Giganon, A.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Gregori, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F.H.; Herrmann, F.; Hinterberger, F.; Hoppner, Ch.; Horikawa, N.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jorg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.; Kramer, M.; Kroumchtein, Z.V.; Kuchinski, N.; Kuhn, R.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G.K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Menon, G.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Moinester, M.A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nunes, Ana Sofia; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pesaro, G.; Pesaro, V.; Peshekhonov, D.V.; Pires, C.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Reymond, J-M.; Rocco, E.; Rossiyskaya, N.S.; Rousse, J.Y.; Ryabchikov, D.I.; Rychter, A.; Samartsev, A.; Samoylenko, V.D.; Sandacz, A.; Sarkar, S.; Savin, I.A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schluter, T.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Schott, M.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Weitzel, Q.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-01-01

    The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This article describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup.

  17. The COMPASS setup for physics with hadron beams

    Science.gov (United States)

    Abbon, P.; Adolph, C.; Akhunzyanov, R.; Alexandrov, Yu.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badełek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Ciliberti, P.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Colantoni, M.; Cotte, D.; Crespo, M. L.; Curiel, Q.; Dafni, T.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Desforge, D.; Dinkelbach, A. M.; Donskov, S. V.; Doshita, N.; Duic, V.; Dünnweber, W.; Durand, D.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Gatignon, L.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giganon, A.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Gregori, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, F.; Hinterberger, F.; Höppner, Ch.; Horikawa, N.; d`Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jörg, P.; Joosten, R.; Kabuß, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kroumchtein, Z. V.; Kuchinski, N.; Kuhn, R.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G. K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Menon, G.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Moinester, M. A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V. I.; Novy, J.; Nowak, W.-D.; Nunes, A. S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pesaro, G.; Pesaro, V.; Peshekhonov, D. V.; Pires, C.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Reymond, J.-M.; Rocco, E.; Rossiyskaya, N. S.; Rousse, J.-Y.; Ryabchikov, D. I.; Rychter, A.; Samartsev, A.; Samoylenko, V. D.; Sandacz, A.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlüter, T.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Terça, G.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Weitzel, Q.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-04-01

    The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This paper describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup.

  18. RIKEN RI beam facility and its physics programme

    International Nuclear Information System (INIS)

    A construction of the radioactive ion beam facility has been started at RIKEN, which is a project to construct a four-sector ring cyclotron (IRC-4) and a six-sector superconducting ring cyclotron (SRC-6), experimental storage rings (MUSES) and an experimental facility. Heavy ions are to be accelerated to energies of up to 400A MeV for light nuclei and 150A MeV for the heaviest nuclei by the SRC-6 and up to 1400A MeV in the MUSES. Wide varieties of radioactive nuclear beams are to be supplied as secondary beams. Electrons, stable nuclei, and highly charged ions in addition to radioactive nuclei can be stored in the storage rings. The MUSES provides various collision methods, such as colliding, merging and internal target modes. A few of the new nuclear-physics opportunities are discussed briefly. (author)

  19. The COMPASS setup for physics with hadron beams

    International Nuclear Information System (INIS)

    The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This paper describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup

  20. Consistency check of photon beam physical data after recommissioning process

    Science.gov (United States)

    Kadman, B.; Chawapun, N.; Ua-apisitwong, S.; Asakit, T.; Chumpu, N.; Rueansri, J.

    2016-03-01

    In radiotherapy, medical linear accelerator (Linac) is the key system used for radiation treatments delivery. Although, recommissioning was recommended after major modification of the machine by AAPM TG53, but it might not be practical in radiotherapy center with heavy workloads. The main purpose of this study was to compare photon beam physical data between initial commissioning and recommissioning of 6 MV Elekta Precise linac. The parameters for comparing were the percentage depth dose (PDD) and beam profiles. The clinical commissioning test cases followed IAEA-TECDOC-1583 were planned on REF 91230 IMRT Dose Verification Phantom by Philips’ Pinnacle treatment planning system. The Delta4PT was used for dose distribution verification with 90% passing criteria of the gamma index (3%/3mm). Our results revealed that the PDDs and beam profiles agreed within a tolerance limit recommended by TRS430. Most of the point doses and dose distribution verification passed the acceptance criteria. This study showed the consistency of photon beam physical data after recommissioning process. There was a good agreement between initial commissioning and recommissioning within a tolerance limit, demonstrated that the full recommissioning process might not be required. However, in the complex treatment planning geometry, the initial data should be applied with great caution.

  1. Some Key Problems Related to Radioactive Ion Beam Physics

    Institute of Scientific and Technical Information of China (English)

    叶沿林; 吕林辉

    2012-01-01

    The latest progress made in the field of radioactive ion beam physics is outlined and the key problems still under investigation are indicated. The focal points are the limit of nuclear existence, shell evolution and new magic numbers, halo and cluster structures, new excitation modes, and strong coupling between reaction channels. This field is still at a starting phase and much more new outcomes are foreseen.

  2. Beam Physics of Integrable Optics Test Accelerator at Fermilab

    OpenAIRE

    Nagaitsev, S.; Valishev, A.; Danilov, V. V.; Shatilov, D. N.

    2013-01-01

    Fermilab's Integrable Optics Test Accelerator is an electron storage ring designed for testing advanced accelerator physics concepts, including implementation of nonlinear integrable beam optics and experiments on optical stochastic cooling. The machine is currently under construction at the Advanced Superconducting Test Accelerator facility. In this report we present the goals and the current status of the project, and describe the details of machine design. In particular, we concentrate on ...

  3. Production of heavy ion beams for atomic physics studies

    International Nuclear Information System (INIS)

    A laboratory for research in atomic physics of ions has been set up around a 2 MV tandem Van de Graaff accelerator designed and built indegenously. Mass analysed negatively charged heavy ion beams from a directly extracted duoplasmatron ion source are injected through various ion-optical elements into the accelerating tube. A gas stripper at the high voltage dome changes the negative ions into positive ions which are subsequently accelerated. The high energy end of the accelerator consists of quadrupole focussing magnets and an analysing magnet. A pair of insulated tantalum slits provide corona feedback and stabilize the energy of the accelerator. A beam resolution of 5 keV at 1 MeV proton energy has been measured. A number of experiments are presently being planned to utilize the accelerator in the field of basic research in atomic physics. These include beam-foil spectroscopic measurements involving detection of decay photon/electrons, ion-induced X-ray emission, analytical applications and radiation damage studies. Electron spectrometers which are in the stage of testing include cylindrical mirror analyser and parallel plate analyser. On the accelerator front, efforts are underway to develop a new sputter ion source and computer automation for improving stability and reliability. The salient features of the accelerator and the instrumentation developed for carrying out experiments in atomic physics are reported. (author). 14 refs., 17 figs

  4. Green synthesis of carbon-supported nanoparticle catalysts by physical vapor deposition on soluble powder substrates

    OpenAIRE

    Hee-Young Park; Injoon Jang; Namgee Jung; Young-Hoon Chung; Jae Yoon Ryu; In Young Cha; Hyung Juhn Kim; Jong Hyung Jang; Sung Jong Yoo

    2015-01-01

    Metal and metal oxide nanoparticles (NPs) supported on high surface area carbon (NP/Cs) were prepared by the physical vapor deposition of bulk materials on an α-D-glucose (Glu) substrate, followed by the deposition of the NPs on carbon supports. Using Glu as a carrier for the transport of NPs from the bulk materials to the carbon support surfaces, ultrafine NPs were obtained, exhibiting a stabilizing effect through OH moieties on the Glu surfaces. This stabilizing effect was strong enough to ...

  5. Thermoelastic stresses in SiC single crystals grown by the physical vapor transport method

    Institute of Scientific and Technical Information of China (English)

    Zibing Zhang; Jing Lu; Qisheng Chen; V.Prasad

    2006-01-01

    A finite element-based thermoelastic anisotropic stress model for hexagonal silicon carbide polytype is developed for the calculation of thermal stresses in SiC crystals grown by the physical vapor transport method.The composite structure of the growing SiC crystal and graphite lid is considered in the model.The thermal expansion match between the crucible lid and SiC crystal is studied for the first time.The influence of thermal stress on the dislocation density and crystal quality iS discussed.

  6. MgB2 ultrathin films fabricated by hybrid physical chemical vapor deposition and ion milling

    Directory of Open Access Journals (Sweden)

    Narendra Acharya

    2016-08-01

    Full Text Available In this letter, we report on the structural and transport measurements of ultrathin MgB2 films grown by hybrid physical-chemical vapor deposition followed by low incident angle Ar ion milling. The ultrathin films as thin as 1.8 nm, or 6 unit cells, exhibit excellent superconducting properties such as high critical temperature (Tc and high critical current density (Jc. The results show the great potential of these ultrathin films for superconducting devices and present a possibility to explore superconductivity in MgB2 at the 2D limit.

  7. Single-crystalline AlN growth on sapphire using physical vapor deposition

    International Nuclear Information System (INIS)

    A novel technique for growing single crystalline aluminum nitride (AlN) films is presented. The novelty of the technique, specifically, comes from the use of an innovative physical vapor deposition magnetron sputtering tool, which embeds magnets into the target material. A relatively high deposition rates is achieved (∼0.2 μm/min), at temperatures between 860 and 940 oC. The AlN, grown onto sapphire, is single-crystalline as evidenced by observation using transmission electron microscopy. Tool configuration and growth conditions are discussed, as well as a first set of other analytical results, namely, x-ray diffraction and ultraviolet-visible transmission spectrophotometry.

  8. α-alumina coatings on WC/Co substrates by physical vapor deposition

    OpenAIRE

    Selinder, T.I.; Coronel, E.; Wallin, Erik; Helmersson, Ulf

    2009-01-01

    Physical vapor deposition coatings for cutting tools may be deposited by, e.g. reactive magnetron sputtering. Alumina growth in Ar/O2 gas mixtures gives rise to problems due to insulating layers on targets, and hysteresis effects with respect to oxygen gas flow. In this paper is described a technology for the deposition of crystalline alumina: reactive high power impulse magnetron sputtering. Pure Al was used as target material, and the cemented carbide (WC/Co) substrates were kept at 500-650...

  9. High energy density physics with intense ion and laser beams. Annual report 2003

    International Nuclear Information System (INIS)

    The following topics are dealt with: Laser plasma physics, plasma spectroscopy, beam interaction experiments, atomic and radiation physics, pulsed power applications, beam transport and accelerator research and development, properties of dense plasma, instabilities in beam-plasma interaction, beam transport in dense plasmas, short-pulse laser-matter interaction. (HSI)

  10. High energy density physics with intense ion and laser beams. Annual report 2003

    Energy Technology Data Exchange (ETDEWEB)

    Weyrich, K. (comp.)

    2004-07-01

    The following topics are dealt with: Laser plasma physics, plasma spectroscopy, beam interaction experiments, atomic and radiation physics, pulsed power applications, beam transport and accelerator research and development, properties of dense plasma, instabilities in beam-plasma interaction, beam transport in dense plasmas, short-pulse laser-matter interaction. (HSI)

  11. A physical palette for ion-beam cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Surdutovich, E.; Solov' yov, A.V. [Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Surdutovich, E. [Oakland Univ., Rochester, MI (United States)

    2009-07-01

    Ion-beam cancer therapy and proton-beam therapy have been used successfully. Despite apparent experimental and clinical successes, a comprehensive theoretical description of a physical scenario is missing. One reason is that the phenomena initiated by an energetic ion incident on tissue happen on many scales in time, distance and energy. DNA is disrupted as a result of energy deposition by incident ions, mainly due to the ionization of the medium. The secondary electrons formed in this process are considered to be mostly responsible for DNA damage through either direct breaking of DNA strands, or reacting with water molecules producing more active secondaries, or through the heating of the medium. Our calculations show that the seemingly insurmountable complexity of the geometry of DNA in different states may be overcome, because the geometrical differences are found to be insignificant. (A.C.)

  12. Accelerator Physics Experiments with Beam Loss Monitors at BESSY

    CERN Document Server

    Kuske, P

    2001-01-01

    The extended use of beam loss monitoring has led to a better understanding of the linear and non-linear physics involved in the single and multiple particle dynamics at BESSY. This knowledge has been used for improving the performance of the light source in terms of lifetime, beam stability, and stability of the energy. The key to these experiments are loss monitors placed at strategic locations of the ring with high sensitivity to Touschek or Coulomb scattered particles. Coulomb-scattering depends strongly on the transverse dynamics which is determined by the magnetic guiding fields. Losses occur primarily at the vertical aperture restrictions imposed by the flat insertion device vacuum chambers. Tune scan measurements clearly show resonances produced by the lattice magnets and by some of the insertion devices. Touschek scattering depends on the 3-dimensional electron density and the spins of the colliding particles. In transfer function type experiments these dependencies have been used to observe the effec...

  13. Physics Potential of Very Intense Conventional Neutrino Beams

    CERN Document Server

    Gómez-Cadenas, J J; Burguet-Castell, J; Casper, David William; DOnega, M; Gilardoni, S S; Hernández, Pilar; Mezzetto, Mauro

    2001-01-01

    The physics potential of high intensity conventional beams is explored. We consider a low energy super beam which could be produced by a proposed new accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve our current knowledge of the atmospheric parameters and measure or severely constrain the parameter connecting the atmospheric and solar realms. It is also shown that a very large water detector could eventually observe leptonic CP violation. The reach of such an experiment to the neutrino mixing parameters would lie in-between the next generation of neutrino experiments (MINOS, OPERA, etc) and a future neutrino factory.

  14. Laser physical and laser chemical vapor deposition of TiN and TiNxOy films

    International Nuclear Information System (INIS)

    The authors have investigated the formation of polycrystalline TiN and amorphous TiNxOy films using laser physical (LPVD) and laser chemical (LCVD) vapor deposition techniques. The LPVD method involved the ablation of a TiN hot pressed pellet and Ti in the presence of nitrogen plasma using nanosecond XeCl excimer laser pulses (wavelength 308nm, pulse duration 45 x 10-9 seconds, and energy density ∼ 4-5 Jcm-2). The films were polycrystalline (average grain size ∼ 100 angstrom) with face-centered-cubic structure and lattice constant of 4.25 angstrom. The average grain size remained constant as the substrate temperature ranged from 25 to 550 degrees C. In the LCVD method, a pulsed CO2 laser beam was used to crack TiCl4 and NH3 and from TiN films. Amorphous TiNxOy films were formed under poor vacuum conditions in the LPVD techniques. These amorphous TiNxOy films often exhibited explosive recrystallization with characteristic star patterns. Resistivity and microhardness measurements were made on these films and these results have been correlated with microstructure and chemical composition

  15. Medical applications of nuclear physics and heavy-ion beams

    International Nuclear Information System (INIS)

    Isotopes and accelerators, hallmarks of nuclear physics, are finding increasingly sophisticated and effective applications in the medical field. Diagnostic and therapeutic uses of radioisotopes are now a $10B/yr business worldwide, with over 10 million procedures and patient studies performed every year. This paper will discuss the use of isotopes for these applications. In addition, beams of protons and heavy ions are being more and more widely used clinically for treatment of malignancies. To be discussed here as well will be the rationale and techniques associated with charged-particle therapy, and the progress in implementation and optimization of these technologies for clinical use

  16. Medical applications of nuclear physics and heavy-ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Jose R.

    2000-08-01

    Isotopes and accelerators, hallmarks of nuclear physics, are finding increasingly sophisticated and effective applications in the medical field. Diagnostic and therapeutic uses of radioisotopes are now a $10B/yr business worldwide, with over 10 million procedures and patient studies performed every year. This paper will discuss the use of isotopes for these applications. In addition, beams of protons and heavy ions are being more and more widely used clinically for treatment of malignancies. To be discussed here as well will be the rationale and techniques associated with charged-particle therapy, and the progress in implementation and optimization of these technologies for clinical use.

  17. Lua(Jit) for computing accelerator beam physics

    CERN Document Server

    CERN. Geneva

    2016-01-01

    As mentioned in the 2nd developers meeting, I would like to open the debate with a special presentation on another language - Lua, and a tremendous technology - LuaJit. Lua is much less known at CERN, but it is very simple, much smaller than Python and its JIT is extremely performant. The language is a dynamic scripting language easy to learn and easy to embedded in applications. I will show how we use it in HPC for accelerator beam physics as a replacement for C, C++, Fortran and Python, with some benchmarks versus Python, PyPy4 and C/C++.

  18. Enhanced synthesis of Sn nanowires with aid of Se atom via physical vapor transport

    Science.gov (United States)

    Cai, Huacheng; Wang, Wendong; Liu, Peiwen; Wang, Guangming; Liu, Ankang; He, Zhe; Cheng, Zhaofang; Zhang, Shengli; Xia, Minggang

    2015-06-01

    We demonstrate tin (Sn) nanowires growth enhanced by Selenium (Se) atoms via physical vapor transport (PVT) method. The Raman spectroscopy, X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy show that Sn nanowires are synthesized with a large quantity, good quality and high purity of Sn. The growth of Sn nanowires is attributed to Solid-Vapor-Liquid mechanism. The effects of gold nanoparticles catalyst, Si substrate, and Se atoms on Sn nanowires growth are discussed in detail. We find that Se atom plays a key role in the growth of Sn nanowires. The gaseous Sn atoms are absorbed by the eutectic alloy droplets of Se-Au at first. Then Sn atoms precipitate at the liquid-solid phase interface due to a supersaturated solution and form a one-dimensional nanostructure. In all, this PVT method could provide a simple and quick way to synthesize monocrystalline Sn nanowires with an advantage in both quality and quantity. The optical transmittance of Sn nanowires thin film with 2 μm2 density approaches 85-90% in visible wavelength. Therefore, the Sn nanowires thin film can be applied to transparent electrode along with their metallic property.

  19. High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

    Science.gov (United States)

    Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

    2014-01-01

    Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

  20. Green synthesis of carbon-supported nanoparticle catalysts by physical vapor deposition on soluble powder substrates

    Science.gov (United States)

    Park, Hee-Young; Jang, Injoon; Jung, Namgee; Chung, Young-Hoon; Ryu, Jae Yoon; Cha, In Young; Kim, Hyung Juhn; Jang, Jong Hyung; Yoo, Sung Jong

    2015-09-01

    Metal and metal oxide nanoparticles (NPs) supported on high surface area carbon (NP/Cs) were prepared by the physical vapor deposition of bulk materials on an α-D-glucose (Glu) substrate, followed by the deposition of the NPs on carbon supports. Using Glu as a carrier for the transport of NPs from the bulk materials to the carbon support surfaces, ultrafine NPs were obtained, exhibiting a stabilizing effect through OH moieties on the Glu surfaces. This stabilizing effect was strong enough to stabilize the NPs, but weak enough to not significantly block the metal surfaces. As only the target materials and Glu are required in our procedure, it can be considered environmentally friendly, with the NPs being devoid of hazardous chemicals. Furthermore, the resulting NP/Cs exhibited an improvement in activity for various electrochemical reactions, mainly attributed to their high surface area.

  1. Thermal recrystallization of physical vapor deposition based germanium thin films on bulk silicon (100)

    KAUST Repository

    Hussain, Aftab M.

    2013-08-16

    We demonstrate a simple, low-cost, and scalable process for obtaining uniform, smooth surfaced, high quality mono-crystalline germanium (100) thin films on silicon (100). The germanium thin films were deposited on a silicon substrate using plasma-assisted sputtering based physical vapor deposition. They were crystallized by annealing at various temperatures ranging from 700 °C to 1100 °C. We report that the best quality germanium thin films are obtained above the melting point of germanium (937 °C), thus offering a method for in-situ Czochralski process. We show well-behaved high-κ /metal gate metal-oxide-semiconductor capacitors (MOSCAPs) using this film. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Microstructure and field emission characteristics of ZnO nanoneedles grown by physical vapor deposition

    International Nuclear Information System (INIS)

    Single crystalline zinc oxide (ZnO) nanoneedles have been grown on Au coated Si (1 0 0) substrates in an inert gas atmosphere by physical vapor deposition (PVD) process. A mixture of ZnO and graphite powder was used as precursor for the production of nanoneedles. Their structure has been assessed by a range of techniques including scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The synthesized ZnO nanoneedles have tip diameter around 30 nm and average length of ∼5 μm. The XRD patterns and HRTEM measurements revealed the highly crystalline phase of wurtzite single crystalline structure, with a preferred growth direction. Field emission from these nanoneedles was investigated and a low turn on voltage of 5.07 V μm-1 at a current density of 10 μA cm-2 was observed.

  3. Fabrication of CdTe solar cells by laser-driven physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.; Bhat, A.; Tabory, C.; Liu, S.; Nguyen, M.; Aydinli, A.; Tsien, L.H.; Bohn, R.G. (Toledo Univ., OH (USA). Dept. of Physics and Astronomy)

    1991-05-01

    Polycrystalline cadmium sulfide-cadmium telluride heterojunction solar cells were fabricated for the first time using a laser-driven physical vapor deposition method. An XeCl excimer laser was used to deposit both of the II-VI semiconductor layers in a single vacuum chamber from pressed powder targets. Results are presented from optical absorption. Raman scattering, X-ray diffraction, and electrical characterization of the films. Solar cells were fabricated by deposition onto SnO{sub 2}-coated glass with top contacts produced by gold evaporation. Device performance was evaluated from the spectral quantum efficiency and current-voltage measurements in the dark and with air mass 1.5 solar illumination. (orig.).

  4. Physical vapor deposition synthesis of tungsten monocarbide (WC) thin films on different carbon substrates

    International Nuclear Information System (INIS)

    The synthesis of tungsten monocarbide (WC) thin films has been performed by physical vapor deposition on various substrates including glassy carbon, carbon fiber sheet, carbon foam, and carbon cloth. The WC and W2C phase contents of these films have been evaluated with bulk and surface analysis techniques such as x-ray diffraction, x-ray photoelectron spectroscopy, and scanning electron microscopy. These characterization techniques were also used to determine the effects of synthesis by nonreactive and reactive sputtering. The synthesis of WC particles supported on the carbon fiber substrate has also been accomplished using the temperature programmed reaction method. Overall, the results demonstrate that the phase purity of tungsten carbides can be controlled by the deposition environment and annealing temperatures

  5. Photoluminescence of CdTe Crystals Grown by Physical Vapor Transport

    Science.gov (United States)

    Palosz, W.; Grasza, K.; Boyd, P. R.; Cui, Y.; Wright, G.; Roy, U. N.; Burger, A.

    2002-01-01

    High quality CdTe crystals with resistivities higher than 10(exp 8) omega cm were grown by the physical vapor transport technique. Indium, Aluminum, and the transition metal Scandium were introduced at the nominal level of about 6 ppm to the source material. Low-temperature photoluminescence (PL) has been employed to identify the origins of PL emissions of the crystals. The emission peaks at 1.584 eV and 1.581 eV were found only in the In-doped crystal. The result suggests that the luminescence line at 1.584 eV is associated with Cd-vacancy/indium complex. The intensity of the broadband centered at 1.43 eV decreases strongly with introduction of Sc.

  6. Photoluminescence of CdTe Crystals Grown by Physical-Vapor Transport

    Science.gov (United States)

    Palosz, W.; Grasza, K.; Boyd, P. R.; Cui, Y.; Wright, G.; Roy, U. N.; Burger, A.

    2003-01-01

    High-quality CdTe crystals with resistivities higher than 10(exp 8) omega cm were grown by the physical-vapor transport (PVT) technique. Indium, aluminum, and the transition-metal scandium were introduced at the nominal level of about 6 ppm to the source material. Low-temperature photoluminescence (PL) has been employed to identify the origins of PL emissions of the crystals. The emission peaks at 1.584 eV and 1.581 eV were found only in the In-doped crystal. The result suggests that the luminescence line at 1.584 eV is associated with Cd-vacancy/In complex. The intensity of the broadband centered at 1.43 eV decreases strongly with introduction of Sc.

  7. Comparison between chemical vapor deposited and physical vapor deposited WSi2 metal gate for InGaAs n-metal-oxide-semiconductor field-effect transistors

    International Nuclear Information System (INIS)

    We compare chemical vapor deposition (CVD) and physical vapor deposition (PVD) WSi2 metal gate process for In0.53Ga0.47As n-metal-oxide-semiconductor field-effect transistors using 10 and 6.5 nm Al2O3 as dielectric layer. The CVD-processed metal gate device with 6.5 nm Al2O3 shows enhanced transistor performance such as drive current, maximum transconductance and maximum effective mobility. These values are relatively better than the PVD-processed counterpart device with improvement of 51.8%, 46.4%, and 47.8%, respectively. The improvement for the performance of the CVD-processed metal gate device is due to the fluorine passivation at the oxide/semiconductor interface and a nondestructive deposition process.

  8. Comparison between chemical vapor deposited and physical vapor deposited WSi2 metal gate for InGaAs n-metal-oxide-semiconductor field-effect transistors

    Science.gov (United States)

    Ong, B. S.; Pey, K. L.; Ong, C. Y.; Tan, C. S.; Antoniadis, D. A.; Fitzgerald, E. A.

    2011-05-01

    We compare chemical vapor deposition (CVD) and physical vapor deposition (PVD) WSi2 metal gate process for In0.53Ga0.47As n-metal-oxide-semiconductor field-effect transistors using 10 and 6.5 nm Al2O3 as dielectric layer. The CVD-processed metal gate device with 6.5 nm Al2O3 shows enhanced transistor performance such as drive current, maximum transconductance and maximum effective mobility. These values are relatively better than the PVD-processed counterpart device with improvement of 51.8%, 46.4%, and 47.8%, respectively. The improvement for the performance of the CVD-processed metal gate device is due to the fluorine passivation at the oxide/semiconductor interface and a nondestructive deposition process.

  9. Physical vapor deposition synthesis of amorphous silicate layers and nanostructures as cosmic dust analogs

    Science.gov (United States)

    De Sio, A.; Tozzetti, L.; Wu, Ziyu; Marcelli, A.; Cestelli Guidi, M.; Della Ventura, G.; Zhao, Haifeng; Pan, Zhiyun; Li, Wenjie; Guan, Yong; Pace, E.

    2016-05-01

    Cosmic dust grains (CD) are part of the evolution of stars and planetary systems and pervade the interstellar medium. Thus, their spectral signature may be used to deduce the physical features of the observed astronomical objects or to study many physical and chemical processes in the interstellar medium. However, CD samples are available only from sample-and-return space missions. Thus, they are rare and not sufficient to be used to perform laboratory experiments of astrophysical interest, such as to produce reference spectra. In this contribution, we describe a new physical vapor deposition (PVD) technique that allows the production of amorphous samples with controlled chemical and morphological characteristics. In particular, this technique was developed to grow uniform or microstructured layers of Mg-Fe amorphous silicates (olivine or pyroxene) that are materials of wide interest for laboratory experiments. We discuss the first results that were achieved by applying this new synthesis method. The layers were studied by combining infrared spectroscopy, scanning electron microscopy, and X-ray spectroscopy. The X-ray microscopy was used for the first time to characterize the internal structure of the grains in these synthetic samples. Finally, future improvements of the technique and foreseen applications are discussed.

  10. Ground-based research of crystal growth of II-VI compound semiconductors by physical vapor transport

    Science.gov (United States)

    Volz, M. P.; Gillies, D. C.; Szofran, F. R.; Lehoczky, S. L.; Su, Ching-Hua; Sha, Yi-Gao; Zhou, W.; Dudley, M.; Liu, Hao-Chieh; Brebrick, R. F.; Wang, J. C.

    1994-01-01

    Ground-based investigation of the crystal growth of II-VI semiconductor compounds, including CdTe, CdS, ZnTe, and ZnSe, by physical vapor transport in closed ampoules was performed. The crystal growth experimental process and supporting activities--preparation and heat treatment of starting materials, vapor partial pressure measurements, and transport rate measurements are reported. The results of crystal characterization, including microscopy, microstructure, optical transmission photoluminescence, synchrotron radiation topography, and chemical analysis by spark source mass spectrography, are also discussed.

  11. Friction and Wear of Ion-Beam-Deposited Diamondlike Carbon on Chemical-Vapor-Deposited, Fine-Grain Diamond

    Science.gov (United States)

    Miyoshi, Kazuhisa; Wu, Richard L. C.; Lanter, William C.

    1996-01-01

    Friction and wear behavior of ion-beam-deposited diamondlike carbon (DLC) films coated on chemical-vapor-deposited (CVD), fine-grain diamond coatings were examined in ultrahigh vacuum, dry nitrogen, and humid air environments. The DLC films were produced by the direct impact of an ion beam (composed of a 3:17 mixture of Ar and CH4) at ion energies of 1500 and 700 eV and an RF power of 99 W. Sliding friction experiments were conducted with hemispherical CVD diamond pins sliding on four different carbon-base coating systems: DLC films on CVD diamond; DLC films on silicon; as-deposited, fine-grain CVD diamond; and carbon-ion-implanted, fine-grain CVD diamond on silicon. Results indicate that in ultrahigh vacuum the ion-beam-deposited DLC films on fine-grain CVD diamond (similar to the ion-implanted CVD diamond) greatly decrease both the friction and wear of fine-grain CVD diamond films and provide solid lubrication. In dry nitrogen and in humid air, ion-beam-deposited DLC films on fine-grain CVD diamond films also had a low steady-state coefficient of friction and a low wear rate. These tribological performance benefits, coupled with a wider range of coating thicknesses, led to longer endurance life and improved wear resistance for the DLC deposited on fine-grain CVD diamond in comparison to the ion-implanted diamond films. Thus, DLC deposited on fine-grain CVD diamond films can be an effective wear-resistant, lubricating coating regardless of environment.

  12. Etching characteristics and application of physical-vapor-deposited amorphous carbon for multilevel resist

    International Nuclear Information System (INIS)

    For the fabrication of a multilevel resist (MLR) based on a very thin, physical-vapor-deposited (PVD) amorphous carbon (a-C) layer, the etching characteristics of the PVD a-C layer with a SiOx hard mask were investigated in a dual-frequency superimposed capacitively coupled plasma etcher by varying the following process parameters in O2/N2/Ar plasmas: high-frequency/low-frequency combination (fHF/fLF), HF/LF power ratio (PHF/PLF), and O2 and N2 flow rates. The very thin nature of the a-C layer helps to keep the aspect ratio of the etched features low. The etch rate of the PVD a-C layer increased with decreasing fHF/fLF combination and increasing PLF and was initially increased but then decreased with increasing N2 flow rate in O2/N2/Ar plasmas. The application of a 30 nm PVD a-C layer in the MLR structure of ArF PR/BARC/SiOx/PVD a-C/TEOS oxide supported the possibility of using a very thin PVD a-C layer as an etch-mask layer for the TEOS-oxide layer

  13. Transport Properties of MgB2 Films Grown by Hybrid Physical Chemical Vapor Deposition Method

    International Nuclear Information System (INIS)

    We prepared four different MgB2 films on Al2O3 by hybrid physical chemical vapor deposition method with thicknesses ranging from 0.65 μm to 1.2 μm X-ray diffraction patterns confirm that all the MgB2 films are c-axis oriented perpendicular to Al2O3 substrates. The superconducting onset temperature of MgB2 films were between 39.39K and 40.72K. The residual resistivity ratio of the MgB2 films was in the range between 3.13 and 37.3. We measured the angle dependence of critical current density (Jc) and resistivity, and determined the upper critical field (Hc2 ) from the temperature dependence of the resistivity curves. The anisotropy ratios defined as the ratio of the (Hc2 ) parallel to the ab-plane to that perpendicular to the ab-plane were in the range of 2.13 to 4.5 and were increased as the temperature was decreased. Some samples showed increase of Jc and decrease of resistivity when a magnetic field in applied parallel to the c-axis. We interpret this angle dependence in terms of enhanced flux pinning due to columnar growth of MgB2 along the c-axis.

  14. Growth of cubic SiC single crystals by the physical vapor transport technique

    Science.gov (United States)

    Semmelroth, K.; Krieger, M.; Pensl, G.; Nagasawa, H.; Püsche, R.; Hundhausen, M.; Ley, L.; Nerding, M.; Strunk, H. P.

    2007-10-01

    Suitable process parameters for the growth of cubic 3C-SiC single crystals via the seeded physical vapor transport (PVT) technique, also known as the modified Lely method, have been determined. Free-standing, 200 μm thick 3C-SiC epilayers with (0 0 1)- or (0 0 1¯)-face grown on undulant Si (0 0 1) as well as 3C-SiC platelets with [1 1 1]- or [1¯ 1¯ 1¯]-orientation grown by thermal decomposition of methyl trichlorosilane in hydrogen were employed as seed crystals. The source material consisted of stoichiometric SiC; in addition, a separate Si source was deposited in the furnace at a temperature of about 1500 °C. The temperature of the seed crystals was kept at about 1900 °C. Stable growth of 3C-SiC bulk material of high crystalline quality was reached on 3C-SiC seed crystals with (0 0 1)-face providing a low density of planar defects and at near-thermal-equilibrium conditions resulting in a reduction of internal stress and as a consequence in avoiding the generation of new extended crystal defects. The growth rate achieved under these conditions was approximately 0.05 mm/h. The nitrogen donor concentration in the grown 3C-SiC crystals was determined to be equal to (2-6)×10 18 cm -3.

  15. Optical and electrical properties of SnS semiconductor crystals grown by physical vapor deposition technique

    International Nuclear Information System (INIS)

    Tin sulfide (SnS) is a material of interest for use as an absorber in low cost solar cells. Single crystals of SnS were grown by the physical vapor deposition technique. The grown crystals were characterized to evaluate the composition, structure, morphology, electrical and optical properties using appropriate techniques. The composition analysis indicated that the crystals were nearly stoichiometric with Sn-to-S atomic percent ratio of 1.02. Study of their morphology revealed the layered type growth mechanism with low surface roughness. The grown crystals had orthorhombic structure with (0 4 0) orientation. They exhibited an indirect optical band gap of 1.06 eV and direct band gap of 1.21 eV with high absorption coefficient (up to 103 cm-1) above the fundamental absorption edge. The grown crystals were of p-type with an electrical resistivity of 120 Ω cm and carrier concentration 1.52x1015 cm-3. Analysis of optical absorption and diffuse reflectance spectra showed the presence of a wide absorption band in the wavelength range 300-1200 nm, which closely matches with a significant part of solar radiation spectrum. The obtained results were discussed to assess the suitability of the SnS crystal for the fabrication of optoelectronic devices.

  16. Solar physical vapor deposition: A new approach for preparing magnesium titanate nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Apostol, Irina [S.C. IPEE Amiral Trading Impex S.A., 115300 Curtea de Arges (Romania); Saravanan, K. Venkata, E-mail: vsk@ua.pt [Department of Materials and Ceramic Engineering, Centre for Research in Ceramics and Composite Materials, CICECO, University of Aveiro, 3810-093 Aveiro (Portugal); Monty, Claude J.A. [CNRS-PROMES Laboratory, Odeillo 66120, Font Romeu (France); Vilarinho, Paula M. [Department of Materials and Ceramic Engineering, Centre for Research in Ceramics and Composite Materials, CICECO, University of Aveiro, 3810-093 Aveiro (Portugal)

    2013-11-15

    Solar energy is a major factor in the equation of energy, because of the unlimited potential of the sun that eclipses all other renewable sources of energy. Solar physical vapor deposition (SPVD) is a core innovative, original and environmentally friendly process to prepare nanocrystalline materials in a powder form. The principle of this process is to melt the material under concentrated solar radiation, which evaporates and condenses as nanopowders on a cold surface. We synthesized nanopowders of magnesium titanate by the SPVD process at PROMES Laboratory in Odeillo-Font Romeu, France. The SPVD system consists of a parabolic mirror concentrator, a mobile plane mirror (“heliostat”) tracking the sun and a solar reactor “heliotron”. The synthesized nanopowders were analyzed by X-ray diffraction (XRD) to know their crystalline structure and scanning electron microscopy (SEM) was used for determining the surface morphology. We have shown that the characteristics of obtained nanotitanates were determined by the targets’ composition and SPVD process parameters such as the working pressure inside the solar reactor and evaporation duration (process time).

  17. Hybrid Physical Chemical Vapor Deposition of Superconducting Magnesium Diboride Coatings for Large Scale Radio Frequency Cavities

    Science.gov (United States)

    Lee, Namhoon; Withanage, Wenura; Tan, Teng; Wolak, Matthaeus; Xi, Xiaoxing

    2016-03-01

    Magnesium diboride (MgB2) is considered to be a great candidate for next generation superconducting radio frequency (SRF) cavities due to its higher critical temperature Tc (40 K) and increased thermodynamic critical field Hc compared to other conventional superconductors. These properties significantly reduce the BCS surface resistance (RsBCS)and residual resistance (Rres) according to theoretical studies and suggest the possibility of an enhanced accelerating field (Eacc) . We have investigated the possibility of coating the inner surface of a 3 GHz SRF cavity with MgB2 by using a hybrid physical-vapor deposition (HPCVD) system which was modified for this purpose. To simulate a real 3 GHz SRF cavity, a stainless steel mock cavity has been employed for the study. The film quality was characterized on small substrates that were placed at selected locations within the cavity. MgB2 films on stainless steel foils, niobium pieces and SiC substrates showed transition temperatures of above 36 K. Dielectric resonance measurements resulted in promising Q values as obtained for the MgB2 films grown on the various substrates. By employing the HPCVD technique, a uniform film was achieved across the cavity interior, demonstrating the feasibility of HPCVD for MgB2 coatings for SRF cavities.

  18. Engineering the Crystalline Morphology of Polymer Thin Films via Physical Vapor Deposition

    Science.gov (United States)

    Jeong, Hyuncheol; Arnold, Craig; Priestley, Rodney

    Thin-film growth via physical vapor deposition (PVD) has been successfully exploited for the delicate control of film structure for molecular and atomic systems. The application of such a high-energetic process to polymeric film growth has been challenged by chemical degradation. However, recent development of Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique opened up a way to deposit a variety of macromolecules in a PVD manner. Here, employing MAPLE technique to the growth of semicrystalline polymer thin films, we show the engineering of crystalline film morphology can be achieved via manipulation of substrate temperature. This is accomplished by exploiting temperature effect on crystallization kinetics of polymers. During the slow film growth crystallization can either be permitted or suppressed, and crystal thickness can be tuned via temperature modulation. In addition, we report that the crystallinity of polymer thin films may be significantly altered with deposition temperature in MAPLE processing. We expect that this ability to manipulate crystallization kinetics during polymeric film growth will open the possibility to engineer structure in thin film polymeric-based devices in ways that are difficult by other means.

  19. New Pulsed Cold Neutron Beam Line for Fundamental Nuclear Physics at LANSCE

    Science.gov (United States)

    Seo, P.-N.; Bowman, J. D.; Gericke, M.; Gillis, R. C.; Greene, G. L.; Leuschner, M. B.; Long, J.; Mahurin, R.; Mitchell, G. S.; Penttila, S. I.; Peralta, G.; Sharapov, E. I.; Wilburn, W. S.

    2005-01-01

    The NPDGamma collaboration has completed the construction of a pulsed cold neutron beam line on flight path12 at the Los Alamos Neutron Science Center (LANSCE). We describe the new beam line and characteristics of the beam. We report results of the moderator brightness and the guide performance measurements. FP12 has the highest pulsed cold neutron intensity for nuclear physics in the world.

  20. Very high temperature chemical vapor deposition of new carbon thin films using organic semiconductor molecular beam sources

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, Takuya [Department of Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Shimada, Toshihiro, E-mail: shimada@chem.s.u-tokyo.ac.j [Department of Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Hanzawa, Akinori; Hasegawa, Tetsuya [Department of Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan)

    2009-11-30

    We carried out the preparation and characterization of new carbon films deposited using an organic molecular beam deposition apparatus with very high substrate temperature (from room temperature to 2670 K), which we newly developed. When we irradiated molecular beam of organic semiconductor perylene tetracarboxylic acid dianhydride (PTCDA) on Y{sub 0.07}Zr{sub 0.93}O{sub 2} (111) at 2170 K, a new carbon material was formed via decomposition and fusing of the molecules. The films were characterized with an atomic force microscope (AFM), Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Zirconium carbide (ZrC) films were identified beneath the topmost carbon layer by XRD and XPS analyses, which results from chemical reactions of the substrate and the molecules. Partially graphitized aromatic rings of PTCDA were observed from Raman spectroscopy. The present technique - very high temperature chemical vapor deposition using organic semiconductor sources - will be useful to study a vast unexplored field of covalent carbon solids.

  1. TEBPP: Theoretical and Experimental study of Beam-Plasma-Physics

    Science.gov (United States)

    Anderson, H. R.; Bernstein, W.; Linson, L. M.; Papadopoulos, K.; Kellogg, P. J.; Szuszczewicz, E. P.; Hallinan, T. J.; Leinbach, H.

    1980-01-01

    The interaction of an electron beam (0 to 10 keV, 0 to 1.5 Amp) with the plasma and neutral atmospheres at 200 to 400 km altitude is studied with emphasis on applications to near Earth and cosmical plasmas. The interaction occurs in four space time regions: (1) near electron gun, beam coming into equilibrium with medium; (2) equilibrium propagation in ionosphere; (3) ahead of beam pulse, temporal and spatial precursors; (4) behind a beam pulse. While region 2 is of the greatest interest, it is essential to study Region 1 because it determines the characteristics of the beam as it enters 2 through 4.

  2. Probing space-time structure of new physics with polarized beams at the international linear collider

    Indian Academy of Sciences (India)

    B Ananthanarayan

    2007-11-01

    At the international linear collider large beam polarization of both the electron and positron beams will enhance the signature of physics due to interactions that are beyond the standard model. Here we review our recently obtained results on a general model-independent method of determining for an arbitary one-particle inclusive state the space-time structure of such new physics through the beam polarization dependence and angular distribution of the final state particle.

  3. Characterization of Plasma Enhanced Chemical Vapor Deposition-Physical Vapor Deposition transparent deposits on textiles to trigger various antimicrobial properties to food industry textiles

    International Nuclear Information System (INIS)

    Textiles for the food industry were treated with an original deposition technique based on a combination of Plasma Enhanced Chemical Vapor Deposition and Physical Vapor Deposition to obtain nanometer size silver clusters incorporated into a SiOCH matrix. The optimization of plasma deposition parameters (gas mixture, pressure, and power) was focused on textile transparency and antimicrobial properties and was based on the study of both surface and depth composition (X-ray Photoelectron Spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), as well as Transmission Electron Microscopy, Atomic Force Microscopy, SIMS depth profiling and XPS depth profiling on treated glass slides). Deposition conditions were identified in order to obtain a variable and controlled quantity of ∼ 10 nm size silver particles at the surface and inside of coatings exhibiting acceptable transparency properties. Microbiological characterization indicated that the surface variable silver content as calculated from XPS and ToF-SIMS data directly influences the level of antimicrobial activity.

  4. Continuous ultra-thin MoS{sub 2} films grown by low-temperature physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Muratore, C. [Department of Chemical and Materials Engineering, University of Dayton, Dayton, Ohio 45469 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Hu, J. J.; Bultman, J. E.; Jespersen, M. L. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); University of Dayton Research Institute, Dayton, Ohio 45469 (United States); Wang, B.; Haque, M. A. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, College Park, Pennsylvania 16802 (United States); Shamberger, P. J.; McConney, M. E.; Naguy, R. D.; Voevodin, A. A. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States)

    2014-06-30

    Uniform growth of pristine two dimensional (2D) materials over large areas at lower temperatures without sacrifice of their unique physical properties is a critical pre-requisite for seamless integration of next-generation van der Waals heterostructures into functional devices. This Letter describes a vapor phase growth technique for precisely controlled synthesis of continuous, uniform molecular layers of MoS{sub 2} on silicon dioxide and highly oriented pyrolitic graphite substrates of over several square centimeters at 350 °C. Synthesis of few-layer MoS{sub 2} in this ultra-high vacuum physical vapor deposition process yields materials with key optical and electronic properties identical to exfoliated layers. The films are composed of nano-scale domains with strong chemical binding between domain boundaries, allowing lift-off from the substrate and electronic transport measurements from contacts with separation on the order of centimeters.

  5. Synthesis of nanocrystalline Cu1-xTax composites using physical vapor deposition

    International Nuclear Information System (INIS)

    Physical vapor deposition (PVD) processes provide the capability for creating new types of metallic, ceramic, and polymeric composites by allowing atomic-scale engineering of structure and chemistry. Because PVD processes provide the capacity for circumventing thermodynamic factors, such as solubility limits, it is possible to produce nonequilibrium alloys and materials with unique mixtures of phases. The ease by which PVD produces materials with nanocrystalline microstructures is an added benefit of these processes. This paper describes ion plating, a plasma-assisted PVD process, and its application for the development of a new class of nanoscale dispersion-strengthened Cu1-xTax alloys. Copper-tantalum was selected as a model system because the extensive liquid miscibility gap and nearly zero mutual solid solubilities prevent creation of Cu-Ta alloys by conventional or rapid solidification processes. Microchemical analyses of the family of Cu1-xTax alloys indicate that PVD can produce materials with any desired level of Ta. X-ray diffraction and transmission electron microscopy analyses show that the as-deposited microstructures consist generally of a Cu matrix supersaturated with Ta and containing a uniform dispersion of Ta particles with diameters below 10 nm. The Ta particles are face centered cubic (exceptionally large Ta particles, larger than ∼100 nm, are body centered cubic) and are oriented identically with the Cu matrix. Particle coarsening studies, at temperatures up to 900C and for times as long as 100 hours, indicate an extreme degree of microstructural stability. The Ta particles also appear highly effective at maintaining a submicron Cu matrix grain size even after annealing at 900C

  6. Dynamic and temperature dependent response of physical vapor deposited Se in freely standing nanometric thin films

    Science.gov (United States)

    Yoon, Heedong; McKenna, Gregory B.

    2016-05-01

    Here, we report results from an investigation of nano-scale size or confinement effects on the glass transition and viscoelastic properties of physical vapor deposited selenium films. The viscoelastic response of freely standing Se films was determined using a biaxial membrane inflation or bubble inflation method [P. A. O'Connell and G. B. McKenna, Science 307, 1760-1763 (2005)] on films having thicknesses from 60 to 267 nm and over temperatures ranging from Tg, macroscopic - 15 °C to Tg, macroscopic + 21 °C. Time-temperature superposition and time-thickness superposition were found to hold for the films in the segmental dispersion. The responses are compared with macroscopic creep and recoverable creep compliance data for selenium [K. M. Bernatz et al., J. Non-Cryst. Solids 307, 790-801 (2002)]. The time-temperature shift factors for the thin films show weaker temperature dependence than seen in the macroscopic behavior, being near to Arrhenius-like in their temperature dependence. Furthermore, the Se films exhibit a "rubbery-like" stiffening that increases as film thickness decreases similar to prior observations [P. A. O'Connell et al., Macromolecules 45(5), 2453-2459 (2012)] for organic polymers. In spite of the differences from the macroscopic behavior in the temperature dependence of the viscoelastic response, virtually no change in Tg as determined from the thickness dependence of the retardation time defining Tg was observed in the bubble inflation creep experiments to thicknesses as small as 60 nm. We also find that the observed rubbery stiffening is consistent with the postulate of K. L. Ngai et al. [J. Polym. Sci., Part B: Polym. Phys. 51(3), 214-224 (2013)] that it should correlate with the change of the macroscopic segmental relaxation.

  7. Deposition of nanoscale multilayer CrN/NbN physical vapor deposition coatings by high power impulse magnetron sputtering

    OpenAIRE

    Purandare, Y. P.; Ehiasarian, A.P.; Hovsepian, P. E.

    2008-01-01

    Nanoscale multilayer CrN/NbN physical vapor deposition (PVD) coatings are gaining reputation for their high corrosion and wear resistance. However, the CrN/NbN films deposited by ABS(TM) (are bond sputtering) technology have some limitations such as macrodroplets, porosity, and less dense structures. The novel HIPIMS (high power impulse magnetron sputtering) technique produces macroparticle-free, highly ionized metal plasma, which brings advantages in both surface pretreatment and coating dep...

  8. Growth of thick MgB2 films by impinging-jet hybrid physical-chemical vapor deposition

    International Nuclear Information System (INIS)

    Thick MgB2 films are grown using a novel impinging-jet hybrid physical-chemical vapor deposition process. An increased amount of the boron source gas generates high growth rates. Superconducting properties of the thick films are comparable to previous results from other processes, which indicate that this is a promising new process for MgB2 deposition for coated conductor applications, such as wires and tapes for MRI magnets. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  9. Growth of thick MgB{sub 2} films by impinging-jet hybrid physical-chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lamborn, D.R. [Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Wilke, R.H.T.; Li, Q. [Department of Physics, The Pennsylvania State University, University Park, PA 16802 (United States); Xi, X. [Department of Physics, Department of Materials Science and Engineering, Materials Research Institute, The Pennsylvania State University, University Park, PA 16801 (United States); Snyder, D.W. [Applied Research Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Redwing, J.M. [Department of Materials Science and Engineering, Materials Research Institute, The Pennsylvania State University, University Park, PA 16801 (United States)

    2008-01-18

    Thick MgB{sub 2} films are grown using a novel impinging-jet hybrid physical-chemical vapor deposition process. An increased amount of the boron source gas generates high growth rates. Superconducting properties of the thick films are comparable to previous results from other processes, which indicate that this is a promising new process for MgB{sub 2} deposition for coated conductor applications, such as wires and tapes for MRI magnets. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  10. The Physics and Applications of High Brightness Beams: Working Group A Summary on High Brightness Beam Production

    International Nuclear Information System (INIS)

    Working group A was devoted to high brightness beam production and characterization. The presentations and discussions could be categorized as cathode physics, new photoinjector designs, computational modeling of high brightness beams, and new experimental methods and results. Several novel injector and cathode designs were presented. However, a standard 1.5 cell rf photoinjector is still the most common source for high brightness beams. New experimental results and techniques were presented and thoroughly discussed. The brightest beam produced in a rf photoinjector published at the time of the workshop is approximately 2 1014 A/(m-rad)2 at Sumitomo Heavy Industries in Japan with 1 nC of charge, a 9 ps FWHM long laser pulse and a normalized transverse emittance of 1.2 pm. The emittance was achieved by utilizing a temporally flat laser pulse which decreased the emittance by an estimated factor of 2 from the beam produced with a Gaussian pulse shape with an identical pulse length

  11. A Physical Description of the Response of Coupled Beams

    DEFF Research Database (Denmark)

    Hugin, Claus Thomas

    1997-01-01

    An analytical method is presented for computing the vibrational response and the net transmitted power of bending wave fields in system consisting of coupled finite beams. The method is based on a wave approach that utilises the reflection and transmission coefficients of the different beam joints...

  12. Nonlinear plasma and beam physics in plasma wake-fields

    International Nuclear Information System (INIS)

    In experimental studies of the Plasma Wake-field Accelerator performed to date at the Argonne Advanced Accelerator Test Facility, significant nonlinearities in both plasma and beam behavior have been observed. The plasma waves driven in the wake of the intense driving beam in these experiments exhibit three-dimensional nonlinear behavior which has as yet no quantitative theoretical explanation. This nonlinearity is due in part to the self-pinching of the driving beam in the plasma, as the denser self-focused beam can excite larger amplitude plasma waves. The self-pinching is a process with interesting nonlinear aspects: the initial evolution of the beam envelope and the subsequent approach to Bennett equilibrium through phase mixing. 35 refs., 10 figs

  13. Correlation between ion beam parameters and physical characteristics of nanostructures fabricated by focused ion beam

    International Nuclear Information System (INIS)

    We report a study of the physical characteristics of the pillars of C, Pt and W grown by 10-30 keV Ga focused ion beam (FIB) as a function of Ga ion flux, and present a quantitative analysis of the elements using energy-dispersive analysis of X-rays (EDAX). All the FIB grown pillars exhibit a rough morphology with whisker like protrusions on the cylindrical surface and broadening of the base as compared to the nominal size. For a constant fluence, the height of the pillar initially increases and then reduces after going through a maximum as a function of ion flux in all the cases. The compositional analysis shows good metallic quality for Pt structures but reveals significant contamination of Ga in C and Ga and C in W structures at higher ion fluxes. Explanation to all these observations has been sought in the light of secondary ion and electron effects and the different processes involved which lead to the FIB induced deposition

  14. Several atomic-physics issues connected with the use of neutral beams in fusion experiments

    International Nuclear Information System (INIS)

    Energetic neutral beams are used for heating and diagnostics in present magnetic fusion experiments. They are also being considered for use in future large experiments. Atomic physics issues are important for both the production of the neutral beams and the interaction of the beams and the plasma. Interest in neutral beams based on negative hydrogen ions is growing, largely based on advances in producing high current ion sources. An extension of the negative ion approach has been the suggestion to use negative ions of Z > 1 elements, such as carbon and oxygen, to form high power neutral beams for plasma heating

  15. Physics Opportunities with Polarized e- and e+ Beams at TESLA

    CERN Document Server

    Moortgat-Pick, G; Moortgat-Pick, Gudrid; Steiner, Herbert M.

    2001-01-01

    Beam polarization at e+ e- linear colliders will be a powerful tool for high precision analyses. Often it is assumed that the full information from polarization effects is provided by polarization of the electron beam and no further information can be obtained by the simultaneous polarization of the positrons. In this paper we point out the advantages of polarizing both beams, and summarize the polarization-related results of the Higgs, Electroweak, QCD, SUSY and Alternative Theories working groups of the ECFA/DESY workshop for a planned linear collider operating in the energy range sqrt{s}= 500-800 GeV.

  16. Detection of slow atoms confined in a Cesium vapor cell by spatially separated pump and probe laser beams

    CERN Document Server

    Todorov, Petko; Maurin, Isabelle; Saltiel, Solomon; Bloch, Daniel

    2013-01-01

    The velocity distribution of atoms in a thermal gas is usually described through a Maxwell-Boltzman distribution of energy, and assumes isotropy. As a consequence, the probability for an atom to leave the surface under an azimuth angle {\\theta} should evolve as cos {\\theta}, in spite of the fact that there is no microscopic basis to justify such a law. The contribution of atoms moving at a grazing incidence towards or from the surface, i.e. atoms with a small normal velocity, here called "slow" atoms, reveals essential in the development of spectroscopic methods probing a dilute atomic vapor in the vicinity of a surface, enabling a sub-Doppler resolution under a normal incidence irradiation. The probability for such "slow" atoms may be reduced by surface roughness and atom-surface interaction. Here, we describe a method to observe and to count these slow atoms relying on a mechanical discrimination, through spatially separated pump and probe beams. We also report on our experimental progresses toward such a g...

  17. Physics of beam self-modulation in plasma wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Lotov, K. V. [Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation)

    2015-10-15

    The self-modulation instability is a key effect that makes possible the usage of nowadays proton beams as drivers for plasma wakefield acceleration. Development of the instability in uniform plasmas and in plasmas with a small density up-step is numerically studied with the focus at nonlinear stages of beam evolution. The step parameters providing the strongest established wakefield are found, and the mechanism of stable bunch train formation is identified.

  18. Colliding beam physics at Fermilab: interaction regions, beam storage, antiproton cooling, production, and colliding

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.K. (ed.)

    1977-01-01

    The purpose of the colliding beams experment department at Fermilab was to bring about collisions of the stored beams in the energy doubler/saver and main ring, and construct experimental areas with appropriate detectors. To explore the feasibility of using the main ring as a storage device, several studies were carried out to investigate beam growth, loss, and the backgrounds in detectors at possible intersection regions. This range of developments constituted the major topics at the 1977 Summer Study reported here. Emphasis in part one is on interaction regions, beam storage, antiproton cooling, production, and colliding. 40 papers from this part are included in the data base. (GHT)

  19. The epithermal neutron beam for BNCT under construction at TAPIRO: Physics

    International Nuclear Information System (INIS)

    A column to provide an epithermal neutron beam suitable for experimental and clinical BNCT is nearing completion at the TAPIRO reactor (ENEA Casaccia, Rome). TAPIRO is a compact, low power (5 kW), helium-cooled, fast reactor. It has a hard neutron spectrum relative even to other fast reactors. In this paper some of the basic physics aspects of designing an epithermal neutron beam are considered, with reference to the TAPIRO beam

  20. A Study of the Beam Physics in the CLIC Drive Beam Decelerator

    CERN Document Server

    Adli, Erik; Stapnes, Steinar

    2009-01-01

    CLIC is a study for a Multi-TeV e+e- linear collider, in which the rf power for the main linacs is extracted from 100 ampere electron drive beams, by the use of specially designed power extraction structures. Up to 90% of the beam energy is extracted from the drive beams along one kilometer long decelerator sectors, rendering the beam transport challenging. We have identified two major challenges for robust beam transport: the significant transverse wakes in the power extraction structures, and the large energy spread induced by the power extraction process. By beam dynamics studies we have qualified power extraction structure designs, leading to the present CLIC baseline structure in which the transverse wakes are sufficiently mitigated. We have further shown that the beam energy spread induced by the deceleration implies that standard 1-to-1 correction might not ensure satisfactory drive beam transport. As alternative, we propose a decelerator orbit correction scheme based on dispersion-free steering and ex...

  1. Physical characterization of energetic heavy-ion beams

    International Nuclear Information System (INIS)

    The maximum energy deposition of high-energy heavy ion beams used for biomedical research and clinical trials is determined by the amount of material in the target volume (e.g., tissue in radiation therapy) and the amount of various materials required for beam control and modification (water columns, ridge filters, collimators, and beam flattening foils). A significant fraction of the incident heavy ion beam will undergo a nuclear reaction in these materials. The products of these nuclear interactions will, in general, have different biological effectiveness, or quality, in the target volume. In the case of radiation therapy and the irradiation of animals, these nuclear interaction products constitute the distal dose as well as the dose to nontarget tissues. This project is concerned with the measurement and prediction of the components of the radiation field, their fluence, and their velocity spectra, all of which are required to predict their biological action. To identify every particle in the radiation field and measure its velocity, a multidetector particle indetification spectrometer has been designed and built, consisting of a channel plate time-of-flight telescope, pulse ionization chambers, and a 10-element silicon detector telescope, as well as scintillation counters and multiwire proportional chamber for beam definition

  2. Forschungszentrum Rossendorf, Institute of Ion Beam Physics and Materials Research. Annual Report 1994

    International Nuclear Information System (INIS)

    This volume contains the 1994 annual report describing the scientific activity of the Institute of Ion Beam Physics and Material Research (Forschungszentrum Rossendorf, FZR). This institute is devoted to the application of ion beams for the modification and analysis of near-surface layers of solids. (MSA)

  3. Physics at a future Neutrino Factory and super-beam facility

    NARCIS (Netherlands)

    Bandyopadhyay, A.; Choubey, S.; Gandhi, R.; Goswami, S.; Roberts, B. L.; Bouchez, J.; Antoniadis, I.; Ellis, J.; Giudice, G. F.; Schwetz, T.; Umasankar, S.; Karagiorgi, G.; Aguilar-Arevalo, A.; Conrad, J. M.; Shaevitz, M. H.; Pascoli, S.; Geer, S.; Campagne, J. E.; Rolinec, M.; Blondel, A.; Campanelli, M.; Kopp, J.; Lindner, M.; Peltoniemi, J.; Dornan, P. J.; Long, K.; Matsushita, T.; Rogers, C.; Uchida, Y.; Dracos, M.; Whisnant, K.; Casper, D.; Chen, Mu-Chun; Popov, B.; Aysto, J.; Marfatia, D.; Okada, Y.; Sugiyama, H.; Jungmann, K.; Lesgourgues, J.; Zisman, M.; Tortola, M. A.; Friedland, A.; Davidson, S.; Antusch, S.; Biggio, C.; Donini, A.; Fernandez-Martinez, E.; Gavela, B.; Maltoni, M.; Lopez-Pavon, J.; Rigolin, S.; Mondal, N.; Palladino, V.; Filthaut, F.; Albright, C.; de Gouvea, A.; Kuno, Y.; Nagashima, Y.; Mezzetto, M.; Lola, S.; Langacker, P.; Baldini, A.; Nunokawa, H.; Meloni, D.; Diaz, M.; King, S. F.; Zuber, K.; Akeroyd, A. G.; Grossman, Y.; Farzan, Y.; Tobe, K.; Aoki, Mayumi; Murayama, H.; Kitazawa, N.; Yasuda, O.; Petcov, S.; Romanino, A.; Chimenti, P.; Vacchi, A.; Smirnov, A. Yu; Couce, E.; Gomez-Cadenas, J. J.; Hernandez, P.; Sorel, M.; Valle, J. W. F.; Harrison, P. F.; Lunardini, C.; Nelson, J. K.; Barger, V.; Everett, L.; Huber, P.; Winter, W.; Fetscher, W.; van der Schaaf, A.

    2009-01-01

    The conclusions of the Physics Working Group of the International Scoping Study of a future Neutrino Factory and super-beam facility (the ISS) are presented. The ISS was carried out by the international community between NuFact05, (the 7th International Workshop on Neutrino Factories and Super-beams

  4. Physics Design Considerations of Diagnostic X Beam Transport System

    CERN Document Server

    Chen, Y J; Chen, Yu-Jiuan; Paul, Arthur C.

    2000-01-01

    Diagnostic X (D-X) transport system would extract the beam from the downstream transport line of the second- axis of the Dual Axis Radiographic Hydrodynamic Test facility (DARHT-II) and transport this beam to the D-X firing point via four branches of the beamline in order to provide four lines of sight for x-ray radiography. The design goal is to generate four DARHT-II-like x-ray pulses on each line of sight. In this paper, we discuss several potential beam quality degradation processes in the passive magnet lattice beamline and indicate how they constrain the D-X beamline design parameters, such as the background pressure, the pipe size, and the pipe material

  5. Physics studies with brilliant narrow-width -beams at the new ELI-NP Facility

    Indian Academy of Sciences (India)

    Dimiter L Balabanski; ELI-NP Science Team

    2014-11-01

    The Extreme Light Infrastructure Nuclear Physics (ELI-NP) Facility in Magurele is a European research centre for ultrahigh intensity lasers, laser–matter interaction, nuclear science and material science using laser-driven radiation beams. It is the first project within the European Strategic Forum for Research Infrastructure (ESFRI) agenda financed by the European Regional Development Fund. The nuclear physics research programme of the facility is focussed on studies with brilliant narrow-width -beams and experiments in extreme laser fields.

  6. Workshop on Physics with Neutral Kaon Beam at JLab (KL2016) Mini-Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Strakovsky, Igor I. [George Washington Univ., Washington, DC (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Amaryan, Moskov [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Chudakov, Eugene A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Meyer, Curtis A. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pennington, Michael R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Ritman, James L. [Forschungszentrum Juelich Institut fuer Kernphysik

    2016-05-01

    The KL2016 Workshop is following the Letter of Intent LoI12-15-001 "Physics Opportunities with Secondary KL beam at JLab" submitted to PAC43 with the main focus on the physics of excited hyperons produced by the Kaon beam on unpolarized and polarized targets with GlueX setup in Hall D. Such studies will broaden a physics program of hadron spectroscopy extending it to the strange sector. The Workshop was organized to get a feedback from the community to strengthen physics motivation of the LoI and prepare a full proposal.

  7. Proceedings of the workshop on atomic physics with fast heavy-ion beams

    International Nuclear Information System (INIS)

    The Workshop on Atomic Physics with Fast Heavy-Ion Beams was held in the Physics Division, Argonne National Laboratory on January 20 and 21, 1983. The meeting brought together approx. 50 practitioners in the field of accelerator-based atomic physics. The workshop was held to focus attention on possible areas of atomic physics research which would benefit from use of the newest generation of accelerators designed to produce intense high-quality beams of fast heavy ions. Abstracts of individual paper were prepared separately for the data base

  8. Porous AlN with a Low Dielectric Constant Synthesized Based on the Physical Vapor Transport Principle

    Science.gov (United States)

    Wang, Hua-Jie; Liu, Xue-Chao; Kong, Hai-Kuan; Xin, Jun; Gao, Pan; Shi, Er-Wei

    2016-07-01

    Porous AlN with low dielectric constant has been synthesized by the sacrificial template method based on the physical vapor transport principle. It is quite different from the traditional method that mixes the matrix with a pore-forming agent and utilizes liquid-phase sintering. The method consists of two parts. Firstly, AlN powder is placed in a graphite crucible. C/AlN composite can be formed by mixing decomposed AlN vapor and volatile carbon originated from a crucible at high temperature. Secondly, pores are formed after removing carbon from the C/AlN composite by an annealing process. The structure, morphology, porosity and properties of porous AlN are characterized. It is shown the obtained porous AlN has a thermal conductivity of 37.3 W/(m K) and a reduced dielectric constant of 5.5-6.1 (at 1 MHz). The porosity measured by a mercury porosimeter is 24.09%. It has been experimentally proved that porous AlN with a sufficiently porous structure and properties can be synthesized based on the vapor-phase principle.

  9. Sixth Summer School on Exotic Beam Physics. Technical Report

    International Nuclear Information System (INIS)

    The aim of the summer school is to nurture the next generation of scientists so that the community will have sufficient manpower to realize the next generation facility for rare-isotope beams (FRIB) and effectively use it when FRIB comes online. A special emphasis will be made to train Ph.D. students from US universities and young post-docs starting to work in one of the fields related to rare-isotope beams. The format of the school is morning lectures, given by prominent researchers in the field, followed by hands-on training sessions in the afternoon. The students will be instructed in how to produce a radioactive ion beam using the National Superconducting Cyclotron Laboratory Coupled Cyclotron Facility. On the last day of the school they will have the opportunity to produce a beam. The School is an annual event and is jointly organized by the 88-Inch Cyclotron, ATLAS, HRIBF, N-Division/LLNL and NSCL, and with the exception of LLNL is rotating among these laboratories. This proposal is for subsistence support for graduate students and post-docs attending the school.

  10. High energy physics with polarized beams and targets. [65 papers

    Energy Technology Data Exchange (ETDEWEB)

    Marshak, M L [ed.

    1976-01-01

    Sixty-six papers are presented as a report on conference sessions held from August 23-27, 1976, at Argonne National Laboratory. Topics covered include: (1) strong interactions; (2) weak and electromagnetic interactions; (3) polarized beams; and (4) polarized targets. A separate abstract was prepared for each paper for ERDA Energy Research Abstracts (ERA) and for the INIS Atomindex. (PMA)

  11. A hybrid CFD-DSMC model designed to simulate rapidly rarefying flow fields and its application to physical vapor deposition

    Science.gov (United States)

    Gott, Kevin

    This research endeavors to better understand the physical vapor deposition (PVD) vapor transport process by determining the most appropriate fluidic model to design PVD coating manufacturing. An initial analysis was completed based on the calculation of Knudsen number from titanium vapor properties. The results show a dense Navier-Stokes solver best describes flow near the evaporative source, but the material properties suggest expansion into the chamber may result in a strong drop in density and a rarefied flow close to the substrate. A hybrid CFD-DSMC solver is constructed in OpenFOAM for rapidly rarefying flow fields such as PVD vapor transport. The models are patched together combined using a new patching methodology designed to take advantage of the one-way motion of vapor from the CFD region to the DSMC region. Particles do not return to the dense CFD region, therefore the temperature and velocity can be solved independently in each domain. This novel technique allows a hybrid method to be applied to rapidly rarefying PVD flow fields in a stable manner. Parameter studies are performed on a CFD, Navier-Stokes continuum based compressible solver, a Direct Simulation Monte Carlo (DSMC) rarefied particle solver, a collisionless free molecular solver and the hybrid CFD-DSMC solver. The radial momentum at the inlet and radial diffusion characteristics in the flow field are shown to be the most important to achieve an accurate deposition profile. The hybrid model also shows sensitivity to the shape of the CFD region and rarefied regions shows sensitivity to the Knudsen number. The models are also compared to each other and appropriate experimental data to determine which model is most likely to accurately describe PVD coating deposition processes. The Navier-Stokes solvers are expected to yield backflow across the majority of realistic inlet conditions, making their physics unrealistic for PVD flow fields. A DSMC with improved collision model may yield an accurate

  12. High energy backward-Compton scattering γ beam for particle and nuclear physics

    International Nuclear Information System (INIS)

    The GeV photon beam at SPring-8 is produced by backward-Compton scattering of laser photons from 8 GeV electrons. The maximum energy of the photon will be above 3 GeV, and the beam intensity will be 107 photons/sec. Polarization of the photon beam will be 100% at the maximum energy with fully polarized laser photons. We report the outline of the quark nuclear physics project with this high-quality high-intensity beam. (author)

  13. Nuclear physics with advanced brilliant gamma beams at ELI–NP

    Directory of Open Access Journals (Sweden)

    Ur Călin A.

    2016-01-01

    Full Text Available The Extreme Light Infrastructure - Nuclear Physics facility is dedicated to nuclear physics studies with the use of extreme electromagnetic radiation. One of the main research system to be installed and operated in the facility is an outstanding high brilliance gamma beam system. The Gamma Beam System of ELI–NP will produce intense, quasi–monochromatic gamma beams via inverse Compton scattering of short laser pulses on relativistic electron beam pulses. The gamma beams available at ELI–NP will allow for the performance of photo-nuclear reactions aiming to reveal the intimate structure of the atomic nucleus. Nuclear Resonance Fluorescence, photo-fission, photo-disintegration reactions above the particle threshold will be used to study the dipole response of nuclei, the structure of the Pygmy resonances, nuclear processes relevant for astrophysics, production and study of exotic neutron–rich nuclei.

  14. Beta Beams: an accelerator based facility to explore Neutrino oscillation physics

    CERN Document Server

    Wildner, E; Hansen, C; De Melo Mendonca, T; Stora, T; Payet, J; Chance, A; Zorin, V; Izotov, I; Rasin, S; Sidorov, A; Skalyga, V; De Angelis, G; Prete, G; Cinausero, M; Kravchuk, VL; Gramegna, F; Marchi, T; Collazuol, G; De Rosa, G; Delbar, T; Loiselet, M; Keutgen, T; Mitrofanov, S; Lamy, T; Latrasse, L; Marie-Jeanne, M; Sortais, P; Thuillier, T; Debray, F; Trophime, C; Hass, M; Hirsh, T; Berkovits, D; Stahl, A

    2011-01-01

    The discovery that the neutrino changes flavor as it travels through space has implications for the Standard Model of particle physics (SM)[1]. To know the contribution of neutrinos to the SM, needs precise measurements of the parameters governing the neutrino oscillations. This will require a high intensity beam-based neutrino oscillation facility. The EURONu Design Study will review three currently accepted methods of realizing this facility (the so-called Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make a decision on the layout and construction of the future European neutrino oscillation facility. ”Beta Beams” produce collimated pure electron neutrino and antineutrino beams by accelerating beta active ions to high energies and letting them decay in a race-track shaped storage ring. EURONu Beta Beams are based on CERNs infrastructure and the fact that some of the already ...

  15. Development of a high pulse rate intense ion beam diode and investigations of the physics of beam formation

    International Nuclear Information System (INIS)

    Virtually all practical applications for intense ion beams require that the beam pulses be generated at high repetition rates. Until the work presented in this thesis, intense ion beam diodes have been able to pulse only a few times per hour at best. A magnetically insulated ion diode capable of producing intense ion beams at high pulse rates has been developed. This diode employs a magnetically confined anode plasma ion source. The high repetition rate pulsed power systems are based upon saturable magnetic switching. Proton beams of 75keV, 10-25A/cm2 and with 100 ns duration have been generated at 90 Hz in four pulse bursts. This diode can also operate at one pulse per minute indefinitely. This capability has been exploited to measure the relative density profile of electrons in the acceleration gap. The diode was backfilled with about 10-2 Torr of He, which was collisionally excited by energetic in the acceleration gap. When the excited He atoms radiatively decayed, the emitted light was measured with 2 ns time resolution and submillimeter space resolution and used to deduce the relative electron density profile. The diode was configured to produce 100 keV Ar+ beams at up to 4 A/cm2. The electron density profile peaked toward the center of the gap and dropped off significantly toward the anode and cathode. The absence of electron density near the physical cathode is evidence for diamagnetic drift of the virtual cathode. Several stages leading to the formation of the diodes virtual cathode and the ion beam were observed. The electron current takes many tens of nanoseconds from when the initial cathode emission to when their Child-Langmuir current is reached. The extent to which this limit is exceeded depends strongly on the configuration of the insulating magnetic field. The delay between when electrons are first observed in the gap spectroscopically and when the beam is formed is independent of the magnetic field configuration

  16. Physics at the new CERN neutron beam line

    CERN Document Server

    Guerrero, C

    2014-01-01

    A new neutron beam line (n_TOF EAR - 2) is being built at CERN within the n_TOF facility. Compared to the existing 185 meters long time - of - flight beam line, the new one (which will operate in parallel) will feature a shorter flight of 20 meters, providing a 2 7 times more intense neutron flux extending from thermal to 300 MeV. The scientific program is now bein g discussed and the first detailed proposals will be refereed by February 2014. This contribution is devoted to present and discuss the expected performance of the facility, briefly, and the details of some of the first measureme nts foreseen for 2014 and 2015.

  17. Molecular dynamics simulation of fabrication of Cu mono-component metallic glass by physical vapor deposition on Zr substrate

    CERN Document Server

    Yu, Yang; Cui, Fenping

    2016-01-01

    In this work, the single-component Cu metallic glass was fabricated by the physical vapor deposition on the Zr (0001) crystal substrate at 100 K using the classical molecular dynamic simulation. The same deposition process was performed on the Cu (1 0 0) and Ni (1 0 0) crystal substrate for comparison, only the Cu crystal deposited layer with the fcc structure can be obtained. When depositing the Cu atoms on the Zr substrate at 300 K, the crystal structure was formed, which indicates that except the suitable substrate, low temperature is also a key factor for the amorphous structure formation. The Cu liquid quenching from 2000 K to 100 K were also simulated with the cooling rate 1012 K/s to form the Cu glass film in this work. The Cu metallic glass from the two different processes (physical vapor deposition and rapid thermal quenching from liquid) revealed the same radial distribution function and X-ray diffraction pattern, but the different microstructure from the coordination number and Voronoi tessellation...

  18. New development of hadron physics at new laser electron beam line (LEP2) of SPring-8

    International Nuclear Information System (INIS)

    This paper introduces the outline of LEPS2 beam line and two types of large detectors (electromagnetic calorimeter BGOegg and solenoid spectrometer), LEPS2/BGOegg experiment, and the target physics using LEPS2 solenoid spectrometer. In LEPS2 beam line, experiments are performed with the improvement of beam intensity by nearly one digit due to the simultaneous incidence of multiple lasers of high output, as well as with the installation of a large solid angle high-resolution detector. In LEPS2/BGOegg experiment, direct observation with a large solid angle of mesons such as π0, η, η', and ω has become possible, which has given expectation for new physics. As one of the physics at the core of BGOegg experiments, there is the systematic examination of interaction between η' and nucleus/nucleon. In the physics using a solenoid spectrometer, the first target is the measurement of penta-quark particle Θ+. (A.O.)

  19. Genomic Physics. Multiple Laser Beam Treatment of Alzheimer's Disease

    Science.gov (United States)

    Stefan, V. Alexander

    2014-03-01

    The synapses affected by Alzheimer's disease can be rejuvenated by the multiple ultrashort wavelength laser beams.[2] The guiding lasers scan the whole area to detect the amyloid plaques based on the laser scattering technique. The scanning lasers pinpoint the areas with plaques and eliminate them. Laser interaction is highly efficient, because of the focusing capabilities and possibility for the identification of the damaging proteins by matching the protein oscillation eigen-frequency with laser frequency.[3] Supported by Nikola Tesla Labs, La Jolla, California, USA.

  20. Physical aspects of electron-beam arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Khan, F.M.; Fullerton, G.D.; Lee, J.M.F.; Moore, V.C.; Levitt, S.H.

    1977-08-01

    The effect of different parameters on dose distribution in electron-beam arc therapy was studied in order to develop a technique for routine clinical use. A special diaphragm was designed to facilitate telecentric rotation. Dosimetry was performed with an ion chamber, film, and LiF powder in cylindrical polystyrene phantoms and an Alderson Rando phantom. Dose distributions were evaluated with regard to dose homogeneity, and a method of sharpening the dose fall-off near the ends of the arc was proposed. Criteria for selection of isocenter depth and field size were developed. Methods of dose calculation, calibration, and treatment planning are discussed.

  1. Course Notes: United States Particle Accelerator School Beam Physics with Intense Space-Charge

    International Nuclear Information System (INIS)

    The purpose of this course is to provide a comprehensive introduction to the physics of beams with intense space charge. This course is suitable for graduate students and researchers interested in accelerator systems that require sufficient high intensity where mutual particle interactions in the beam can no longer be neglected. This course is intended to give the student a broad overview of the dynamics of beams with strong space charge. The emphasis is on theoretical and analytical methods of describing the acceleration and transport of beams. Some aspects of numerical and experimental methods will also be covered. Students will become familiar with standard methods employed to understand the transverse and longitudinal evolution of beams with strong space charge. The material covered will provide a foundation to design practical architectures. In this course, we will introduce you to the physics of intense charged particle beams, focusing on the role of space charge. The topics include: particle equations of motion, the paraxial ray equation, and the Vlasov equation; 4-D and 2-D equilibrium distribution functions (such as the Kapchinskij-Vladimirskij, thermal equilibrium, and Neuffer distributions), reduced moment and envelope equation formulations of beam evolution; transport limits and focusing methods; the concept of emittance and the calculation of its growth from mismatches in beam envelope and from space-charge non-uniformities using system conservation constraints; the role of space-charge in producing beam halos; longitudinal space-charge effects including small amplitude and rarefaction waves; stable and unstable oscillation modes of beams (including envelope and kinetic modes); the role of space charge in the injector; and algorithms to calculate space-charge effects in particle codes. Examples of intense beams will be given primarily from the ion and proton accelerator communities with applications from, for example, heavy-ion fusion, spallation

  2. Fundamental physics research using a low energy muon beam

    International Nuclear Information System (INIS)

    A process is proposed for the production of true muonium, in which the simultaneous generation of positive and negative muons is utilized in the discovery of new and more compact leptonic atoms. The proposed method, which is based on the use of a low energy muon apparatus, has certain advantages and could lead to the long-awaited appearance of positive and negative muons in the bound state, a goal that has been pursued for a half century. In this apparatus, the formation of true muonium is obtained by frictional cooling with an electron cyclotron resonance plasma,followed by the detection of high energy gamma rays. Simulation studies using the GEANT4 code were applied to the development of this low energy beam apparatus in order to provide evidence for the validity of the frictional cooling principle. (author)

  3. Intense Electron Beams from GaAs Photocathodes as a Tool for Molecular and Atomic Physics

    OpenAIRE

    Krantz, C.

    2009-01-01

    We present cesium-coated GaAs photocathodes as reliable sources of intense, quasi-monoenergetic electron beams in atomic and molecular physics experiments. In long-time operation of the Electron Target of the ion storage ring TSR in Heidelberg, cold electron beams could be realised at steadily improving intensity and reliability. Minimisation of processes degrading the quantum efficiency allowed to increase the extractable current to more than 1mA at stable cathode lifetimes of 24 h or more. ...

  4. Beam Size Estimation from Luminosity Scans at the LHC During 2015 Proton Physics Operation

    CERN Document Server

    Hostettler, Michael

    2016-01-01

    As a complementary method for measuring the beam size for high-intensity beams at 6.5 TeV flat-top energy, beam separation scans were done regularly at the CERN Large Hadron Collider (LHC) during 2015 proton physics operation. The luminosities measured by the CMS experiment during the scans were used to derive the convoluted beam size and orbit offset bunch-by-bunch. This contribution will elaborate on the method used to derive plane-by-plane, bunch-by-bunch emittances from the scan data, including uncertainties and corrections. The measurements are then compared to beam size estimations from absolute luminosity, synchrotron light telescopes, and wire scanners. In particular, the evolution of the emittance over the course of several hours in collisions is studied and bunch-by-bunch differences are highlighted.

  5. Physical studies of beam delivery system for proton and heavy ion treatment

    International Nuclear Information System (INIS)

    We report design and optimization of beam delivery system for proton and heavy ion particles, which will be constructed in charged particle therapy facility in Hyogo Prefecture. Penumbra sizes were calculated for different systems to optimize device parameters under considering effects of multiple scattering and energy loss of beam. It was found that penumbra size of carbon ion beam was about three times smaller than that of proton, and that devices which affect physically in particle delivery system should be placed as upstream as possible to reduce penumbra size. (author)

  6. Accelerator and detector physics at the Bern medical cyclotron and its beam transport line

    Directory of Open Access Journals (Sweden)

    Auger Martin

    2016-03-01

    Full Text Available The cyclotron laboratory for radioisotope production and multi-disciplinary research at the Bern University Hospital (Inselspital is based on an 18-MeV proton accelerator, equipped with a specifically conceived 6-m long external beam line, ending in a separate bunker. This facility allows performing daily positron emission tomography (PET radioisotope production and research activities running in parallel. Some of the latest developments on accelerator and detector physics are reported. They encompass novel detectors for beam monitoring and studies of low current beams.

  7. Developing an expert system to control a beam line at the Los Alamos Meson Physics Facility

    International Nuclear Information System (INIS)

    High energy particle experiments require an accelerator as a source of high energy particles. To increase the productivity of an accelerator facility, we wish to develop an expert system to control beam lines. Expert Systems are a branch of Artificial Intelligence where a computer program performs tasks requiring human expertise. Unlike most expert systems we have a physical model underlying our beam line and this model can be used with the expert system to improve performance. The development of the expert system will lead to an increased understanding of the beam line as well as the possibility of state-of-the-art expert system building

  8. Effects of physical guidance on short-term learning of walking on a narrow beam

    OpenAIRE

    Domingo, Antoinette; Ferris, Daniel P.

    2009-01-01

    Physical guidance is often used in rehabilitation when teaching patients to re-learn movements. However, the effects of guidance on motor learning of complex skills, such as walking balance, are not clear. We tested four groups of healthy subjects that practiced walking on a narrow (1.27 cm) or wide (2.5 cm) treadmill-mounted balance beam, with or without physical guidance. Assistance was given by springs attached to a hip belt that applied restoring forces towards beam center. Subjects were ...

  9. Regularly arranged indium islands on glass/molybdenum substrates upon femtosecond laser and physical vapor deposition processing

    Science.gov (United States)

    Ringleb, F.; Eylers, K.; Teubner, Th.; Boeck, T.; Symietz, C.; Bonse, J.; Andree, S.; Krüger, J.; Heidmann, B.; Schmid, M.; Lux-Steiner, M.

    2016-03-01

    A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass, which can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide used in photovoltaics. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD.

  10. Quantum correlations by four-wave mixing in an atomic vapor in a non-amplifying regime: a quantum beam splitter for photons

    CERN Document Server

    Glorieux, Quentin; Guibal, Samuel; Likforman, Jean-Pierre; Coudreau, Thomas; 10.1103/PhysRevA.84.053826

    2011-01-01

    We study the generation of intensity quantum correlations using four-wave mixing in a rubidium vapor. The absence of cavity in these experiments allows to deal with several spatial modes simultaneously. In the standard, amplifying, configuration, we measure relative intensity squeezing up to 9.2 dB below the standard quantum limit. We also theoretically identify and experimentally demonstrate an original regime where, despite no overall amplification, quantum correlations are generated. In this regime a four-wave mixing set-up can therefore play the role of a photonic beam splitter with non--classical properties, i.e. a device that splits a coherent state input into two quantum correlated beams.

  11. Ion-assisted doping of 2-6 compounds during physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bube, R H [Stanford Univ., CA (USA). Dept. of Materials Science and Engineering

    1990-07-01

    This report describes a research program to (1) investigate ion-assisted doping during chemical vapor deposition of CdTe and (2) determine the influence of co-depositing ionized dopant atoms in the growth and structural and photoelectronic properties of the deposited films. In p-CdTe homo-epitaxial films, we controlled doping up to about 6 {times} 10{sup 16} cm{sup {minus}3} and 2 {times} 10{sup 17} cm{sub {minus}3} or ion-assisted depositions with As and P ions, respectively. At a growth rate of approximately 0.1 {mu}m/min, a substrate temperature of 400{degree}C, and ion energy of 60 eV, a maximum doping density was found near an ion current of 0.6{mu}A/cm{sup 2}. Related studies included elucidating the role of low-energy ion damage in the ion-assisted doping process, and investigating the decrease in carrier density near the surface of p-CdTe upon heating in vacuum, H{sub 2}, or Ar. We demonstrate the ability to make carrier density profiles and to grade junctions, and we present preliminary results from polycrystalline p-CdTe films grown on graphite and alumina substrates. We also present solar cells prepared using the p-CdTe as the collector area and n-CdS as the window layer, and we examine their photovoltaic parameters for different carrier densities and configurations in p-CdTe. 91 refs., 44 figs., 5 tabs.

  12. Radio-frequency quadrupole trap as a tool for experimental beam physics

    International Nuclear Information System (INIS)

    In recent papers [Okamoto, Hiroshima University Preprint HUBP-01/98 (1998); Okamoto and Tanaka, Nucl. Instr. Meth. A 437 (1999) 178], we proposed a novel experimental approach to investigate various collective effects in space-charge-dominated beams. It was demonstrated that either a radio-frequency quadrupole trap or a solenoidal trap could reproduce non-linear processes equivalent to those in a beam transport channel. In the present work, we study the former trap configuration in more detail, specifying a typical parameter range for beam-physics applications. A three-dimensional Maxwell-equation solver is employed to show the basic characteristics of the plasma confinement field. After deriving several useful formulae, we discuss possible trap experiments that greatly deepen our current understandings of collective beam instabilities including coherent resonances, halo formation, etc

  13. Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P.; Friedman, A.

    2010-04-28

    background plasma. If controlled, this physical effect can be used for optimized beam transport over long distances.

  14. Physics of Neutralization of Intense Charged Particle Beam Pulses by a Background Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kaganovich, I.D.; Davidson, R.C.; Dorf, M.A.; Startsev, E.A.; Sefkow, A.B; Friedman, A.F.; Lee, E.P.

    2009-09-03

    through the background plasma. If controlled, this physical effect can be used for optimized beam transport over long distances.

  15. Physics of Neutralization of Intense Charged Particle Beam Pulses by a Background Plasma

    International Nuclear Information System (INIS)

    through the background plasma. If controlled, this physical effect can be used for optimized beam transport over long distances.

  16. Physics of intense light ion beams and production of high energy density in matter. Annual report 1994

    International Nuclear Information System (INIS)

    This report presents the results obtained in 1994 within the FZK-program on 'Physics of intense ion beams and pulsed plasmas'. It describes the present status of the 6 MW, 2 TW pulsed generator KALIF-HELIA, the production and focussing of high power ion beams and numerical simulations and experiments related to the hydrodynamics of beam matter interaction. (orig.)

  17. Highly ionized physical vapor deposition plasma source working at very low pressure

    Czech Academy of Sciences Publication Activity Database

    Straňák, V.; Herrendorf, A.-P.; Drache, S.; Čada, Martin; Hubička, Zdeněk; Tichý, M.; Hippler, R.

    2012-01-01

    Roč. 100, č. 14 (2012), "141604-1"-"141604-3". ISSN 0003-6951 R&D Projects: GA TA ČR TA01010517; GA ČR(CZ) GAP205/11/0386; GA ČR GAP108/12/1941 Institutional research plan: CEZ:AV0Z10100522 Keywords : magnetron * ECWR * low-pressure * sputtering * plasma diagnostics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.794, year: 2012 http://dx.doi.org/10.1063/1.3699229

  18. Physical parameters and biological effects of the LVR-15 epithermal neutron beam

    International Nuclear Information System (INIS)

    Monitoring of the physical and biological properties of the epithermal neutron beam constructed at the multipurpose LVR-15 nuclear reactor for NCT therapy of brain tumors showed that its physical and biological properties are stable in time and independent on an ad hoc reconfiguration of the reactor core before its therapeutic use. Physical parameters were monitored by measurement of the neutron spectrum, neutron profile, fast neutron kerma rate in tissue and photon absorbed dose, the gel dosimetry was used with the group of standard measurement methods. The RBE of the beam, as evaluated by 3 different biological models, including mouse intestine crypt regeneration assay, germinative zones of the immature rat brain and C6 glioma cells in culture, ranged from 1.70 to 1.99. (author)

  19. Induction-accelerator heavy-ion fusion: Status and beam physics issues

    International Nuclear Information System (INIS)

    Inertial confinement fusion driven by beams of heavy ions is an attractive route to controlled fusion. In the U.S., induction accelerators are being developed as open-quotes driversclose quotes for this process. This paper is divided into two main sections. In the first section, the concept of induction-accelerator driven heavy-ion fusion is briefly reviewed, and the U.S. program of experiments and theoretical investigations is described. In the second, a open-quotes taxonomyclose quotes of space-charge-dominated beam physics issues is presented, accompanied by a brief discussion of each area

  20. Thickness dependence of grain growth orientation in MgB2 films fabricated by hybrid physical-chemical vapor deposition

    International Nuclear Information System (INIS)

    We have investigated the effect of thickness of the MgB2 film on the grain growth direction as well as on their superconducting properties. MgB2 films of various thicknesses were fabricated on c-cut Al2O3 substrates at a temperature of 540 degree by using hybrid physical-chemical vapor deposition (HPCVD) technique. The superconducting transition temperature (Tc) was found to increase with increase in the thickness of the MgB2 film. X-ray diffraction analysis revealed that the orientation of grains changed from c-axis to a-axis upon increasing the thickness of the MgB2 film from 0.6 to 2.0 μm. MgB2 grains of various orientations were observed in the microstructures of the films examined by scanning electron microscopy. It is observed that at high magnetic fields the 2.0-μm-thick film exhibit considerably larger critical current density (Jc) as compared to 0.6-μm-thick film. The results are discussed in terms of an intrinsic-pinning in MgB2 similarly as intrinsic-pinning occurring in high-Tc cuprate superconductors with layered structure.

  1. Growth of high quality mercurous halide single crystals by physical vapor transport method for AOM and radiation detection applications

    Science.gov (United States)

    Amarasinghe, Priyanthi M.; Kim, Joo-Soo; Chen, Henry; Trivedi, Sudhir; Qadri, Syed B.; Soos, Jolanta; Diestler, Mark; Zhang, Dajie; Gupta, Neelam; Jensen, Janet L.; Jensen, James

    2016-09-01

    Single crystals of mercurous halide were grown by physical vapor transport method (PVT). The orientation and the crystalline quality of the grown crystals were determined using high resolution x-ray diffraction (HRXRD) technique. The full width at half maximum (FWHM) of the grown mercurous bromide crystals was measured to be 0.13 degrees for (004) reflection, which is the best that has been achieved so far for PVT grown mercurous halide single crystals. The extended defects of the crystals were also analyzed using high resolution x-ray diffraction topography. Preliminary studies were carried out to evaluate the performance of the crystals on acousto-optic modulator (AOM) and gamma-ray detector applications. The results indicate the grown mercurous halide crystals are excellent materials for acousto-optic modulator device fabrication. The diffraction efficiencies of the fabricated AOM device with 1152 and 1523 nm wavelength lasers polarizing parallel to the acoustic wave were found to be 35% and 28%, respectively. The results also indicate the grown crystals are a promising material for gamma-ray detector application with a very high energy resolution of 1.86% FWHM.

  2. Beam Polarization at the ILC: the Physics Impact and the Accelerator Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Aurand, B.; /Bonn U.; Bailey, I.; /Liverpool U.; Bartels, C.; /DESY /DESY, Zeuthen; Brachmann, A.; /SLAC; Clarke, J.; /Daresbury; Hartin, A.; /DESY /DESY, Zeuthen /Oxford U., JAI; Hauptman, J.; /Iowa State U.; Helebrant, C.; /DESY /DESY, Zeuthen; Hesselbach, S.; /Durham U., IPPP; Kafer, D.; List, J.; /DESY /DESY, Zeuthen; Lorenzon, W.; /Michigan U.; Marchesini, I.; Monig, Klaus; /DESY /DESY, Zeuthen; Moffeit, K.C.; /SLAC; Moortgat-Pick, G.; /Durham U., IPPP; Riemann, S.; Schalicke, A.; Schuler, P.; /DESY /DESY, Zeuthen; Starovoitov, P.; /Minsk, NCPHEP; Ushakov, A.; /DESY /DESY, Zeuthen /Bonn U. /SLAC

    2011-11-23

    In this contribution accelerator solutions for polarized beams and their impact on physics measurements are discussed. Focus are physics requirements for precision polarimetry near the interaction point and their realization with polarized sources. Based on the ILC baseline programme as described in the Reference Design Report (RDR), recent developments are discussed and evaluated taking into account physics runs at beam energies between 100 GeV and 250 GeV, as well as calibration runs on the Z-pole and options as the 1TeV upgrade and GigaZ. The studies, talks and discussions presented at this conference demonstrated that beam polarization and its measurement are crucial for the physics success of any future linear collider. To achieve the required precision it is absolutely decisive to employ multiple devices for testing and controlling the systematic uncertainties of each polarimeter. The polarimetry methods for the ILC are complementary: with the upstream polarimeter the measurements are performed in a clean environment, they are fast and allow to monitor time-dependent variations of polarization. The polarimeter downstream the IP will measure the disrupted beam resulting in high background and much lower statistics, but it allows access to the depolarization at the IP. Cross checks between the polarimeter results give redundancy and inter-calibration which is essential for high precision measurements. Current plans and issues for polarimeters and also energy spectrometers in the Beam Delivery System of the ILC are summarized in reference [28]. The ILC baseline design allows already from the beginning the operation with polarized electrons and polarized positrons provided the spin rotation and the fast helicity reversal for positrons will be implemented. A reversal of the positron helicity significantly slower than that of electrons is not recommended to not compromise the precision and hence the success of the ILC. Recently to use calibration data at the Z

  3. Preconcentration, speciation and determination of ultra trace amounts of mercury by modified octadecyl silica membrane disk/electron beam irradiation and cold vapor atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Mercury (II) and methyl mercury cations at the Sub-ppb level were adsorbed quantitatively from aqueous solution onto an octadecyl-bonded silica membrane disk modified by 2-[(2-mercaptophyenylimino)methyl] phenol (MPMP). The trapped mercury was then eluted with 3 ml ethanol and Hg2+ ion was directly measured by cold vapor atomic absorption spectrometry, utilizing tin (II) chloride. Total mercury (Hgt) was determined after conversion of MeHg+ into Hg2+ ion by electron beam irradiation. A sample volume of 1500 ml resulted in a preconcentration factor of 500 and the precision for a sampling volume of 500 ml at a concentration of 2.5 μg l-1 (n = 7) was 3.1%. The limit of detection of the proposed method is 3.8 ng l-1. The method was successfully applied to analysis of water samples, and the accuracy was assessed via recovery experiment

  4. Induction-accelerator heavy-ion fusion: Status and beam physics issues

    International Nuclear Information System (INIS)

    Inertial confinement fusion driven by beams of heavy ions is an attractive route to controlled fusion. In the U.S., induction accelerators are being developed as open-quote open-quote drivers close-quote close-quote for this process. This paper is divided into two main sections. In the first section, the concept of induction-accelerator driven heavy-ion fusion is briefly reviewed, and the U.S. program of experiments and theoretical investigations is described. In the second, a open-quote open-quote taxonomy close-quote close-quote of space-charge-dominated beam physics issues is presented, accompanied by a brief discussion of each area. copyright 1996 American Institute of Physics

  5. Ion-beam inertial fusion: the requirements posed by target and deposition physics

    International Nuclear Information System (INIS)

    The demonstration of ICF scientific feasibility requires success in target design, driver development and target fabrication. Since these are interrelated, we present here some results of ion beam target studies and relate them to parameters of interest to ion accelerators. Ion deposition physics have long been a well known subject apart from high beam currents. Recent NRL experiments at up to 250 kA/cm2 ions confirm the classical deposition physics now at current densities which are comparable to most ion targets. On the other hand, GSI data at low current density but 1 to 10 MeV/nucleon are continually being accumulated. They have yet to find anomalous results. Relying on target concepts outlined briefly, we report on the energy gain of ion-driven fusion targets as a function of input energy, ion ranges and focal spot radius. We also comment on some consequences of target gain versus driver and reactor requirements

  6. Commissioning experience and beam physics measurements at the SwissFEL Injector Test Facility

    CERN Document Server

    Schietinger, T; Aiba, M; Arsov, V; Bettoni, S; Beutner, B; Calvi, M; Craievich, P; Dehler, M; Frei, F; Ganter, R; Hauri, C P; Ischebeck, R; Ivanisenko, Y; Janousch, M; Kaiser, M; Keil, B; Löhl, F; Orlandi, G L; Loch, C Ozkan; Peier, P; Prat, E; Raguin, J -Y; Reiche, S; Schilcher, T; Wiegand, P; Zimoch, E; Anicic, D; Armstrong, D; Baldinger, M; Baldinger, R; Bertrand, A; Bitterli, K; Bopp, M; Brands, H; Braun, H H; Brönnimann, M; Brunnenkant, I; Chevtsov, P; Chrin, J; Citterio, A; Divall, M Csatari; Dach, M; Dax, A; Ditter, R; Divall, E; Falone, A; Fitze, H; Geiselhart, C; Guetg, M W; Hämmerli, F; Hauff, A; Heiniger, M; Higgs, C; Hugentobler, W; Hunziker, S; Janser, G; Kalantari, B; Kalt, R; Kim, Y; Koprek, W; Korhonen, T; Krempaska, R; Laznovsky, M; Lehner, S; Pimpec, F Le; Lippuner, T; Lutz, H; Mair, S; Marcellini, F; Marinkovic, G; Menzel, R; Milas, N; Pal, T; Pollet, P; Portmann, W; Rezaeizadeh, A; Ritt, S; Rohrer, M; Schär, M; Schebacher, L; Scherrer, St; Schmidt, V Schlott T; Schulz, L; Smit, B; Stadler, M; Steffen, B; Stingelin, L; Sturzenegger, W; Treyer, D M; Trisorio, A; Tron, W; Vicario, C; Zennaro, R; Zimoch, D

    2016-01-01

    The SwissFEL Injector Test Facility operated at the Paul Scherrer Institute between 2010 and 2014, serving as a pilot plant and testbed for the development and realization of SwissFEL, the X-ray Free-Electron Laser facility under construction at the same institute. The test facility consisted of a laser-driven rf electron gun followed by an S-band booster linac, a magnetic bunch compression chicane and a diagnostic section including a transverse deflecting rf cavity. It delivered electron bunches of up to 200 pC charge and up to 250 MeV beam energy at a repetition rate of 10 Hz. The measurements performed at the test facility not only demonstrated the beam parameters required to drive the first stage of an FEL facility, but also led to significant advances in instrumentation technologies, beam characterization methods and the generation, transport and compression of ultra-low-emittance beams. We give a comprehensive overview of the commissioning experience of the principal subsystems and the beam physics meas...

  7. Investigation on polarized proton and deuteron beams at the Kharkov institute of physics and technology

    International Nuclear Information System (INIS)

    The short review concerning the investigations of the structure of light nuclei and mechanisms of nuclear reactions on accelerated polarized ion beams performed in the Kharkov Institute of Physics and Technology is presented. The short analysis of works for the past 30 years has been fulfilled. It is shown that the polarization investigations are very necessary for obtaining the information on the nuclear structure and nuclear reaction mechanism. (author). 92 refs

  8. Physical characterization of single convergent beam device for teletherapy: theoretical and Monte Carlo approach.

    Science.gov (United States)

    Figueroa, R G; Valente, M

    2015-09-21

    The main purpose of this work is to determine the feasibility and physical characteristics of a new teletherapy device of radiation therapy based on the application of a convergent x-ray beam of energies like those used in radiotherapy providing highly concentrated dose delivery to the target. We have denominated it Convergent Beam Radio Therapy (CBRT). Analytical methods are developed first in order to determine the dosimetry characteristic of an ideal convergent photon beam in a hypothetical water phantom. Then, using the PENELOPE Monte Carlo code, a similar convergent beam that is applied to the water phantom is compared with that of the analytical method. The CBRT device (Converay(®)) is designed to adapt to the head of LINACs. The converging beam photon effect is achieved thanks to the perpendicular impact of LINAC electrons on a large thin spherical cap target where Bremsstrahlung is generated (high-energy x-rays). This way, the electrons impact upon various points of the cap (CBRT condition), aimed at the focal point. With the X radiation (Bremsstrahlung) directed forward, a system of movable collimators emits many beams from the output that make a virtually definitive convergent beam. Other Monte Carlo simulations are performed using realistic conditions. The simulations are performed for a thin target in the shape of a large, thin, spherical cap, with an r radius of around 10-30 cm and a curvature radius of approximately 70 to 100 cm, and a cubed water phantom centered in the focal point of the cap. All the interaction mechanisms of the Bremsstrahlung radiation with the phantom are taken into consideration for different energies and cap thicknesses. Also, the magnitudes of the electric and/or magnetic fields, which are necessary to divert clinical-use electron beams (0.1 to 20 MeV), are determined using electromagnetism equations with relativistic corrections. This way the above-mentioned beam is manipulated and guided for its perpendicular impact

  9. Physical characterization of single convergent beam device for teletherapy: theoretical and Monte Carlo approach

    International Nuclear Information System (INIS)

    The main purpose of this work is to determine the feasibility and physical characteristics of a new teletherapy device of radiation therapy based on the application of a convergent x-ray beam of energies like those used in radiotherapy providing highly concentrated dose delivery to the target. We have denominated it Convergent Beam Radio Therapy (CBRT). Analytical methods are developed first in order to determine the dosimetry characteristic of an ideal convergent photon beam in a hypothetical water phantom. Then, using the PENELOPE Monte Carlo code, a similar convergent beam that is applied to the water phantom is compared with that of the analytical method.The CBRT device (Converay®) is designed to adapt to the head of LINACs. The converging beam photon effect is achieved thanks to the perpendicular impact of LINAC electrons on a large thin spherical cap target where Bremsstrahlung is generated (high-energy x-rays). This way, the electrons impact upon various points of the cap (CBRT condition), aimed at the focal point. With the X radiation (Bremsstrahlung) directed forward, a system of movable collimators emits many beams from the output that make a virtually definitive convergent beam.Other Monte Carlo simulations are performed using realistic conditions. The simulations are performed for a thin target in the shape of a large, thin, spherical cap, with an r radius of around 10–30 cm and a curvature radius of approximately 70 to 100 cm, and a cubed water phantom centered in the focal point of the cap. All the interaction mechanisms of the Bremsstrahlung radiation with the phantom are taken into consideration for different energies and cap thicknesses.Also, the magnitudes of the electric and/or magnetic fields, which are necessary to divert clinical-use electron beams (0.1 to 20 MeV), are determined using electromagnetism equations with relativistic corrections. This way the above-mentioned beam is manipulated and guided for its perpendicular impact upon

  10. The physical chemistry of nucleation of sub-micrometer non-oxide ceramic powders via sub-oxide vapor-phase reduction reaction

    International Nuclear Information System (INIS)

    Fine ceramic powders (< 500 nm) exhibit exceptional physical and mechanical properties in engineered structural ceramics. The production of fine powders, in particular the non-oxide ceramics, via a cheaper route than the organic solvent route has been rather elusive. This paper examines the physical chemistry of sub-oxide vapor-phase reduction reaction for the nucleation of non-oxide ceramic phase. Well known vapor species eg SiO and BO in the production of technical ceramic powders (SiC, BN) are particularly discussed for understanding the nucleation process of SiC and BN ceramic phases respectively. The regimes of partial pressures and temperatures are particularly identified. The calculated nucleation rate as a function of the temperature is compared with the experimental results on powder morphology. The production of amorphous and nanocrystalline h-BN powders is discussed in the context of substrate structure and thermodynamic parameters

  11. Effects of deposition conditions on gas-barrier performance of SiOxNy thin films formed via ion-beam-assisted vapor deposition

    International Nuclear Information System (INIS)

    SiOxNy thin films were synthesized via ion-beam-assisted vapor deposition (IVD) where deposition of SiOx was irradiated by nitrogen ions. Firstly, reasonable-cost evaporation materials showing less splashing for the SiOx films were investigated by selecting appropriate sintering condition regimes of Si and SiO2 mixed powders. The SiOxNy thin films on a polyethylene terephtalate film substrate obtained via IVD showed a low oxygen transmission rate (OTR) of less than 1 cm3/m2 day. Effective nitrogen ion irradiation energy per atom was 8 eV/at. or greater, which is consistent with regimes where densification of thin films is reported to occur. Higher N2 partial pressure yielded a lower OTR and a higher nitrogen atomic ratio of the films obtained. It is suggested that the improvement in gas-barrier performance resulted from densification and chemical change of the films due to energy addition and nitrification produced by nitrogen ion-beam irradiation

  12. Amorphous silicon carbonitride diaphragm for environmental-cell transmission electron microscope fabricated by low-energy ion beam induced chemical vapor deposition

    Science.gov (United States)

    Matsutani, Takaomi; Yamasaki, Kayo; Imaeda, Norihiro; Kawasaki, Tadahiro

    2015-12-01

    An amorphous silicon carbonitride (a-SiCN) diaphragm for an environmental-cell transmission electron microscope (E-TEM) was fabricated by low-energy ion beam induced chemical vapor deposition (LEIBICVD) with hexamethyldisilazane (HMDSN). The films were prepared by using gaseous HMDSN and N2+ ions with energies ranging from 300 to 600 eV. The diaphragms were applied to Si (1 0 0) and a Cu grid with 100-μm-diameter holes. With increasing ion energy, these diaphragms became perfectly smooth surfaces (RMS = 0.43 nm at 600 eV), as confirmed by atomic force microscopy and TEM. The diaphragms were amorphous and transparent to 200 kV electrons, and no charge-up was observed. Fourier transform infrared spectra and X-ray photoelectron spectra revealed that the elimination of organic compounds and formation of Si-N and C-N bonds can be promoted in diaphragms by increasing the ion impact energy. The resistance to electron beams and reaction gases in the E-cell was improved when the diaphragm was formed with high ion energy.

  13. Deposition of nanoscale multilayer CrN/NbN physical vapor deposition coatings by high power impulse magnetron sputtering

    International Nuclear Information System (INIS)

    Nanoscale multilayer CrN/NbN physical vapor deposition (PVD) coatings are gaining reputation for their high corrosion and wear resistance. However, the CrN/NbN films deposited by ABS (arc bond sputtering) technology have some limitations such as macrodroplets, porosity, and less dense structures. The novel HIPIMS (high power impulse magnetron sputtering) technique produces macroparticle-free, highly ionized metal plasma, which brings advantages in both surface pretreatment and coating deposition stages of the PVD process. In this study, nanoscale multilayer CrN/NbN PVD coatings were pretreated and deposited with HIPIMS technology and compared with those deposited by HIPIMS-UBM (unbalanced magnetron) and by the ABS technique. In all cases Cr+ etching was utilized to enhance adhesion by low energy ion implantation. The coatings were deposited at 400 deg. C with substrate biased (Ub) at -75 V. During coating deposition, HIPIMS produced significantly high activation of nitrogen compared to the UBM as observed with mass spectroscopy. HIPIMS-deposited coatings revealed a bilayer period of 4.1 nm (total thickness: 2.9 μm) and hardness of 3025 HK0.025. TEM results revealed droplet free, denser microstructure with (200) preferred orientation for the HIPIMS coating owing to the increased ionization as compared to the more porous structure with random orientation observed in UBM coating. The dry sliding wear coefficient (Kc) of the coating was 1.8x10-15 m3 N-1 m-1, whereas the steady state coefficient of friction was 0.32. Potentiodynamic polarization tests revealed higher Ecorr values, higher pitting resistance (around potentials +400 to +600 mV), and lower corrosion current densities for HIPIMS deposited coatings as compared to the coatings deposited by ABS or HIPIMS-UBM. The corrosion behavior of the coatings qualitatively improved with the progressive use of HIPIMS from pretreatment stage to the coating deposition step

  14. Integrating atomic layer deposition and ultra-high vacuum physical vapor deposition for in situ fabrication of tunnel junctions

    International Nuclear Information System (INIS)

    Atomic Layer Deposition (ALD) is a promising technique for growing ultrathin, pristine dielectrics on metal substrates, which is essential to many electronic devices. Tunnel junctions are an excellent example which require a leak-free, ultrathin dielectric tunnel barrier of typical thickness around 1 nm between two metal electrodes. A challenge in the development of ultrathin dielectric tunnel barriers using ALD is controlling the nucleation of dielectrics on metals with minimal formation of native oxides at the metal surface for high-quality interfaces between the tunnel barrier and metal electrodes. This poses a critical need for integrating ALD with ultra-high vacuum (UHV) physical vapor deposition. In order to address these challenges, a viscous-flow ALD chamber was designed and interfaced to an UHV magnetron sputtering chamber via a load lock. A sample transportation system was implemented for in situ sample transfer between the ALD, load lock, and sputtering chambers. Using this integrated ALD-UHV sputtering system, superconductor-insulator-superconductor (SIS) Nb-Al/Al2O2/Nb Josephson tunnel junctions were fabricated with tunnel barriers of thickness varied from sub-nm to ∼1 nm. The suitability of using an Al wetting layer for initiation of the ALD Al2O3 tunnel barrier was investigated with ellipsometry, atomic force microscopy, and electrical transport measurements. With optimized processing conditions, leak-free SIS tunnel junctions were obtained, demonstrating the viability of this integrated ALD-UHV sputtering system for the fabrication of tunnel junctions and devices comprised of metal-dielectric-metal multilayers

  15. Physical vapor deposited titanium thin films for biomedical applications: Reproducibility of nanoscale surface roughness and microbial adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Lüdecke, Claudia [Chair of Materials Science (CMS), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, D-07743, Jena (Germany); Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Bio Pilot Plant, Beutenbergstraße 11a, D-07745, Jena (Germany); Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Jena (Germany); Bossert, Jörg [Chair of Materials Science (CMS), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, D-07743, Jena (Germany); Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Jena (Germany); Roth, Martin [Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Bio Pilot Plant, Beutenbergstraße 11a, D-07745, Jena (Germany); Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Jena (Germany); Jandt, Klaus D., E-mail: k.jandt@uni-jena.de [Chair of Materials Science (CMS), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, D-07743, Jena (Germany); Jena Center for Soft Mater, Friedrich Schiller University Jena, Jena (Germany); Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Jena (Germany)

    2013-09-01

    The surface topography is of great importance for the biological performance of titanium based implants since it may influence the initial adsorption of proteins, cell response, as well as microbial adhesion. A recently described technique for the preparation of titanium thin films with an adjustable surface roughness on the nanometer scale is the physical vapor deposition (PVD). The aims of this study were to statistically evaluate the reproducibility of nanorough titanium thin films prepared by PVD using an atomic force microscopy (AFM) based approach, to test the microbial adhesion in dependence of the nanoscale surface roughness and to critically discuss the parameters used for the characterization of the titanium surfaces with respect to AFM microscope settings. No statistically significant differences were found between the surface nanoroughnesses of the PVD prepared titanium thin films. With increasing surface nanoroughness, the coverage by Escherichia coli decreased and the microbial cells were increasingly patchy distributed. The calculated roughness values significantly increased with increasing AFM scan size, while image resolution and pixel density had no influence on this effect. Our study shows that PVD is a suitable tool to reproducibly prepare titanium thin films with a well-defined surface topography on the nanometer scale. These surfaces are, thus, a suitable 2D model system for studies addressing the interaction between surface nanoroughness and the biological system. First results show that surface roughness even on the very low nanometer scale has an influence on bacterial adhesion behavior. These findings give new momentum to biomaterials research and will support the development of biomaterials surfaces with anti-infectious surface properties.

  16. Intense electron beams from GaAs photocathodes as a tool for molecular and atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, Claude

    2009-10-28

    We present cesium-coated GaAs photocathodes as reliable sources of intense, quasi-monoenergetic electron beams in atomic and molecular physics experiments. In long-time operation of the Electron Target of the ion storage ring TSR in Heidelberg, cold electron beams could be realised at steadily improving intensity and reliability. Minimisation of processes degrading the quantum efficiency allowed to increase the extractable current to more than 1mA at usable cathode lifetimes of 24 h or more. The benefits of the cold electron beam with respect to its application to electron cooling and electron-ion recombination experiments are discussed. Benchmark experiments demonstrate the superior cooling force and energy resolution of the photoelectron beam compared to its thermionic counterparts. The long period of operation allowed to study the long-time behaviour of the GaAs samples during multiple usage cycles at the Electron Target and repeated in-vacuum surface cleaning by atomic hydrogen exposure. An electron emission spectroscopy setup has been implemented at the photocathode preparation chamber of the Electron Target. Among others, this new facility opened the way to a novel application of GaAs (Cs) photocathodes as robust, ultraviolet-driven electron emitters. Based on this principle, a prototype of an electron gun, designed for implementation at the HITRAP setup at GSI, has been built and taken into operation successfully. (orig.)

  17. Intense electron beams from GaAs photocathodes as a tool for molecular and atomic physics

    International Nuclear Information System (INIS)

    We present cesium-coated GaAs photocathodes as reliable sources of intense, quasi-monoenergetic electron beams in atomic and molecular physics experiments. In long-time operation of the Electron Target of the ion storage ring TSR in Heidelberg, cold electron beams could be realised at steadily improving intensity and reliability. Minimisation of processes degrading the quantum efficiency allowed to increase the extractable current to more than 1mA at usable cathode lifetimes of 24 h or more. The benefits of the cold electron beam with respect to its application to electron cooling and electron-ion recombination experiments are discussed. Benchmark experiments demonstrate the superior cooling force and energy resolution of the photoelectron beam compared to its thermionic counterparts. The long period of operation allowed to study the long-time behaviour of the GaAs samples during multiple usage cycles at the Electron Target and repeated in-vacuum surface cleaning by atomic hydrogen exposure. An electron emission spectroscopy setup has been implemented at the photocathode preparation chamber of the Electron Target. Among others, this new facility opened the way to a novel application of GaAs (Cs) photocathodes as robust, ultraviolet-driven electron emitters. Based on this principle, a prototype of an electron gun, designed for implementation at the HITRAP setup at GSI, has been built and taken into operation successfully. (orig.)

  18. Physical approach to depth dose distributions in a water phantom irradiated by a teleisotope photon beam

    International Nuclear Information System (INIS)

    The physical basis of deposition of radiation dose within a homogeneous phantom irradiated by a monoenergetic photon beam has been studied in terms of photon attenuation and energy-absorption properties of the phantom material. A semi-empirical model based on the Klein--Nishina formula for Compton scattering, and the ratio of multiply scattered to singly scattered photon fluences, has been developed for the scatter dose component within a realistic phantom to determine the central-axial percent depth dose (PDD) and off-central-axis ratios (OCR). Differences between the predicted and measured values of PDD and OCR for cobalt-60 and cesium-137 beams are less than 3% for fields of equivalent-square-side less than 20 cm, and less than 5% for larger fields. Beam profiles of all field sizes can be well simulated by this model and reasonable agreement has been found between the predicted and tabulated values of scatter functions and the backscatter factor for cobalt-60 beams. This formulation involves no variable parameters, and is valid for all values of the source-to-surface distance, field length and width, and field shape. However, the algorithm developed is not suitable for routine multiple-field treatment planning because it requires large computer memory size

  19. Physics design of the injector source for ITER neutral beam injector (invited).

    Science.gov (United States)

    Antoni, V; Agostinetti, P; Aprile, D; Cavenago, M; Chitarin, G; Fonnesu, N; Marconato, N; Pilan, N; Sartori, E; Serianni, G; Veltri, P

    2014-02-01

    Two Neutral Beam Injectors (NBI) are foreseen to provide a substantial fraction of the heating power necessary to ignite thermonuclear fusion reactions in ITER. The development of the NBI system at unprecedented parameters (40 A of negative ion current accelerated up to 1 MV) requires the realization of a full scale prototype, to be tested and optimized at the Test Facility under construction in Padova (Italy). The beam source is the key component of the system and the design of the multi-grid accelerator is the goal of a multi-national collaborative effort. In particular, beam steering is a challenging aspect, being a tradeoff between requirements of the optics and real grids with finite thickness and thermo-mechanical constraints due to the cooling needs and the presence of permanent magnets. In the paper, a review of the accelerator physics and an overview of the whole R&D physics program aimed to the development of the injector source are presented. PMID:24593568

  20. Physics at a future Neutrino Factory and super-beam facility

    CERN Document Server

    Bandyopadhyay, A; Gandhi, R; Goswami, S; Roberts, B L; Bouchez, J; Antoniadis, I; Ellis, J; Giudice, G F; Schwetz, T; Umansankar, S; Karagiorgi, G; Aguilar-Arevalo, A; Conrad, J M; Shaevitz, M H; Pascoli, Silvia; Geer, S; Rolinec, M; Blondel, A; Campanelli, M; Kopp, J; Lindner, M; Peltoniemi, J; Dornan, P J; Long, K; Matsushita, T; Rogers, C; Uchida, Y; Dracos, M; Whisnant, K; Casper, D; Chen, Mu-Chun; Popov, B; Aysto, J; Marfatia, D; Okada, Y; Sugiyama, H; Jungmann, K; Lesgourgues, J; Murayama, France H; Zisman, M; Tortola, M A; Friedland, A; Antusch, S; Biggio, C; Donini, A; Fernandez-Martinez, E; Gavela, B; Maltoni, M; Lopez-Pavon, J; Rigolin, S; Mondal, N; Palladino, V; Filthaut, F; Albright, C; de Gouvea, A; Kuno, Y; Nagashima, Y; Mezzetoo, M; Lola, S; Langacker, P; Baldini, A; Nunokawa, H; Meloni, D; Diaz, M; King, S F; Zuber, K; Akeroyd, A G; Grossman, Y; Farzan, Y; Tobe, K; Aoki, Mayumi; Kitazawa, N; Yasuda, O; Petcov, S; Romanino, A; Chimenti, P; Vacchi, A; Smirnov, A Yu; Couce, Italy E; Gomez-Cadenas, J J; Hernandez, P; Sorel, M; Valle, J W F; Harrison, P F; Lundardini, C; Nelson, J K; Barger, V; Everett, L; Huber, P; Winter, W; Fetscher, W; van der Schaaf, A

    2009-01-01

    The conclusions of the Physics Working Group of the international scoping study of a future Neutrino Factory and super-beam facility (the ISS) are presented. The ISS was carried by the international community between NuFact05, (the 7th International Workshop on Neutrino Factories and Superbeams, Laboratori Nazionali di Frascati, Rome, June 21-26, 2005) and NuFact06 (Ivine, California, 24{30 August 2006). The physics case for an extensive experimental programme to understand the properties of the neutrino is presented and the role of high-precision measurements of neutrino oscillations within this programme is discussed in detail. The performance of second generation super-beam experiments, beta-beam facilities, and the Neutrino Factory are evaluated and a quantitative comparison of the discovery potential of the three classes of facility is presented. High-precision studies of the properties of the muon are complementary to the study of neutrino oscillations. The Neutrino Factory has the potential to provide ...

  1. Accelerators and Beams, multimedia computer-based training in accelerator physics

    International Nuclear Information System (INIS)

    We are developing a set of computer-based tutorials on accelerators and charged-particle beams under an SBIR grant from the DOE. These self-paced, interactive tutorials, available for Macintosh and Windows platforms, use multimedia techniques to enhance the user close-quote s rate of learning and length of retention of the material. They integrate interactive On-Screen Laboratories, hypertext, line drawings, photographs, two- and three-dimensional animations, video, and sound. They target a broad audience, from undergraduates or technicians to professionals. Presently, three modules have been published (Vectors, Forces, and Motion), a fourth (Dipole Magnets) has been submitted for review, and three more exist in prototype form (Quadrupoles, Matrix Transport, and Properties of Charged-Particle Beams). Participants in the poster session will have the opportunity to try out these modules on a laptop computer. copyright 1999 American Institute of Physics

  2. Treatment of cancer of the pancreas by intraoperative electron beam therapy: physical and biological aspects

    Energy Technology Data Exchange (ETDEWEB)

    Bagne, F.R.; Dobelbower, R.R. Jr.; Milligan, A.J.; Bronn, D.G.

    1989-01-01

    Radiation therapy has had a significant and an expanded role in the management of cancer of the pancreas during the last decade. In particular, for locally advanced disease, radiation therapy has improved the median survival of patients to 1 year. Intraoperative electron beam therapy has been applied to unresectable and resectable pancreatic cancer in an attempt to enhance local control of disease and to improve patient survival. This paper presents a survey of the role of radiation therapy in treatment of cancer of the pancreas, provides information on the radiobiological aspects of this treatment modality and details the physical and dosimetric characteristics of intraoperative radiation therapy with electrons. Presented are the design specifics of an applicator system, central axis beam data, applicator parameters, dose distribution data, shielding, treatment planning and means of verification. Emphasis is placed on the collaboration and cooperation necessary for all members of the intraoperative radiation therapy team including surgeons, radiation therapists, medical physicists, anesthesiologists, technologists, and nurses.29 references.

  3. Evaporation temperature-tuned physical vapor deposition growth engineering of one-dimensional non-Fermi liquid tetrathiofulvalene tetracyanoquinodimethane thin films

    DEFF Research Database (Denmark)

    Sarkar, I.; Laux, M.; Demokritova, J.;

    2010-01-01

    We describe the growth of high quality tetrathiofulvalene tetracyanoquinodimethane (TTF-TCNQ) organic charge-transfer thin films which show a clear non-Fermi liquid behavior. Temperature dependent angle resolved photoemission spectroscopy and electronic structure calculations show that the growth...... of TTF-TCNQ films is accompanied by the unfavorable presence of neutral TTF and TCNQ molecules. The quality of the films can be controlled by tuning the evaporation temperature of the precursor in physical vapor deposition method. © 2010 American Institute of Physics....

  4. CdTe-based solar cells prepared by physical vapor deposition and close-spaced sublimation methods

    International Nuclear Information System (INIS)

    Full text : In the photovoltaic material family, cadmium telluride is regarded as one of the most promising material for fabrication of high efficiency polycrystalline CdTe/CdS thin film solar cells because of its near-optimum band gap of about 1.46 eV and high optical absorption coefficient in visible range. The maximum efficiency of about 16.5 percent of the laboratory samples of polycrystalline CdTe based thin film solar cells was achieved by using nanostructured CdS:O window layer and the modified device structure. In spite of the large lattice mismatch between cubic CdTe and hexagonal CdS (nearly 9.7 percent) the CdTe/CdS solar cells are characterized by essentially high efficiencies caused by interdiffusion at the junction interface removing the lattice mismatch. To identify the structural mechanisms leading to the solar cell efficiency increase we have studied the effect of CdCl2 treatment on the output parameters of CdS/CdTe-based solar cells and crystal structure of the base layers deposited on glass substrates by different ways. In the first way both of CdS and CdTe layers were deposited by physical vapor deposition (PVD) method meanwhile in the second way the chemical bath deposition (CBD) and close-spaced sublimation (CSS) methods were used for CdS and CdTe films deposition, respectively. For the PVD structures. The average grain size of the film increases from 1 μm to 4 μm due to the lattice strain caused by macrodeformations and stacking faults. The maximum efficiency (ηA=10.3 percent) of solar cells on the basis of cadmium telluride layers deposited by PVD method corresponds to 0,35 μm CdRl2 thickness at CdCl2 treatment. CBD/CSS samples were exposed to CdCl2 vapor at 400 degrees Celsium for 5-7 min in vacuum chamber in the presence of 100 torr oxygen and 400 torr helium. As-grown CdTe films were characterized by clearly faceted surface morphology and an average grain size of about 3-4 μm. Unlike the thermally evaporated CdTe films, no

  5. Transverse Beam Polarizationas an Alternate View into New Physics at CLIC

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, Thomas G.; /SLAC

    2011-08-12

    In e{sup +}e{sup -} collisions, transverse beam polarization can be a useful tool in studying the properties of particles associated with new physics beyond the Standard Model(SM). However, unlike in the case of measurements associated with longitudinal polarization, the formation of azimuthal asymmetries used to probe this physics in the case of transverse polarization requires both e{sup {+-}} beams to be simultaneously polarized. In this paper we discuss the further use of transverse polarization as a probe of new physics models at a high energy, {radical}s = 3 TeV version of CLIC. In particular, we show (i) how measurements of the sign of these asymmetries is sufficient to discriminate the production of spin-0 supersymmetric states from the spin-1/2 Kaluza-Klein excitations of Universal Extra Dimensions. Simultaneously, the contribution to this asymmetry arising from the potentially large SM W{sup +}W{sup -} background can be made negligibly small. We then show (ii) how measurements of such asymmetries and their associated angular distributions on the peak of a new resonant Z{prime}-like state can be used to extract precision information on the Z{prime} couplings to the SM fermions.

  6. New frontiers in nuclear physics with high-power lasers and brilliant monochromatic gamma beams

    Science.gov (United States)

    Gales, S.; Balabanski, D. L.; Negoita, F.; Tesileanu, O.; Ur, C. A.; Ursescu, D.; Zamfir, N. V.

    2016-09-01

    The development of high power lasers and the combination of such novel devices with accelerator technology has enlarged the science reach of many research fields, in particular particle and nuclear physics, astrophysics as well as societal applications in material science, nuclear energy and applications for medicine. The European Strategic Forum for Research Infrastructures has selected a proposal based on these new premises called the Extreme Light Infrastructure (ELI). The ELI will be built as a network of three complementary pillars at the frontier of laser technologies. The ELI-NP pillar (NP for nuclear physics) is under construction near Bucharest (Romania) and will develop a scientific program using two 10 PW lasers and a Compton back-scattering high-brilliance and intense low-energy gamma beam, a combination of laser and accelerator technology at the frontier of knowledge. This unique combination of beams that are unique worldwide allows us to develop an experimental program in nuclear physics at the frontiers of present-day knowledge as well as society driven applications. In the present paper, the technical description of the facility as well as the new perspectives in nuclear structure, nuclear reactions and nuclear astrophysics will be presented.

  7. A nuclear physics program at the Rare Isotope Beams Accelerator Facility in Korea

    Directory of Open Access Journals (Sweden)

    Chang-Bum Moon

    2014-02-01

    Full Text Available This paper outlines the new physics possibilities that fall within the field of nuclear structure and astrophysics based on experiments with radioactive ion beams at the future Rare Isotope Beams Accelerator facility in Korea. This ambitious multi-beam facility has both an Isotope Separation On Line (ISOL and fragmentation capability to produce rare isotopes beams (RIBs and will be capable of producing and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. The large dynamic range of reaccelerated RIBs will allow the optimization in each nuclear reaction case with respect to cross section and channel opening. The low energy RIBs around Coulomb barrier offer nuclear reactions such as elastic resonance scatterings, one or two particle transfers, Coulomb multiple-excitations, fusion-evaporations, and direct capture reactions for the study of the very neutron-rich and proton-rich nuclides. In contrast, the high energy RIBs produced by in-flight fragmentation with reaccelerated ions from the ISOL enable to explore the study of neutron drip lines in intermediate mass regions. The proposed studies aim at investigating the exotic nuclei near and beyond the nucleon drip lines, and to explore how nuclear many-body systems change in such extreme regions by addressing the following topics: the evolution of shell structure in areas of extreme proton to neutron imbalance; the study of the weak interaction in exotic decay schemes such as beta-delayed two-neutron or two-proton emission; the change of isospin symmetry in isobaric mirror nuclei at the drip lines; two protons or two neutrons radioactivity beyond the drip lines; the role of the continuum states including resonant states above the particle-decay threshold in exotic nuclei; and the effects of nuclear reaction rates triggered by the unbound proton-rich nuclei on nuclear astrophysical processes.

  8. A multi-scale approach to the physics of ion beam cancer therapy

    CERN Document Server

    Solov'yov, A V; Scifoni, E; Mishustin, I; Greiner, W

    2008-01-01

    We propose a multi-scale approach to understanding physics related to the ion/proton-beam cancer therapy and calculation of the probability of the DNA damage as a result of irradiation of patients with energetic (up to 430 MeV/u) ions. This approach is inclusive with respect to different scales starting from the long scale defined by the ion stopping followed by a smaller scale defined by secondary electrons and radicals ending with the shortest scale defined by interactions of secondaries with the DNA. We present calculations of the probabilities of single and double strand breaks of the DNA and suggest a way of further elaboration of such calculations.

  9. Physical properties of LDPE/ethylene-1-butene copolymer film irradiated by electron beam

    International Nuclear Information System (INIS)

    In this study, ethylene-1-butene copolymer (EBP) was blended with LDPE to improve the mechanical properties as the packaging materials. After they were irradiated by electron beam, their physical properties such as tensile strength, elongation, modulus, peel strength, DSC, DMA were examined. The results showed that the addition of EBP to LDPE exerted significant effects on the mechanical properties such as the tensile strength and peel strength. The addition of EBP led to a maximum increase in peel strength of ∼430%. The addition of 10 - 25 w% EBP in LDPE was sufficient to enhance the peel strength significantly. (author)

  10. The preparation of particle beams for experiments of hadron physics: Slow extraction at ELFE rate at DESY and ELSA, as well as beam cooling at HERA

    International Nuclear Information System (INIS)

    Various complementary experimental approaches are possible to study hadron physics, all of which require dedicated accelerator facilities. One approach, known as the ELFE rate at DESY project, makes use of a continuous electron beam with an energy of 15 to 25 GeV, a current of at least 30 μA and very small emittance, for fixed target experiments. The formation of such a beam by stretching a pulsed LINAC beam with the help of the HERA electron ring has been studied. At lower beam energies and currents this concept is already being used at the ELSA facility of Bonn University. Here the extraction process has been studied intensively and has been compared with measurements. Another approach to study hadron physics is the use of an electron - ion collider. To achieve high integrated luminosities cooling of the ion beam is necessary, especially in the case of heavy ions. For HERA high energy beam cooling with the help of an electron storage ring has been studied. (orig.)

  11. Elementary reaction schemes for physical and chemical vapor deposition of transition metal oxides on silicon for high-k gate dielectric applications

    Science.gov (United States)

    Niu, D.; Ashcraft, R. W.; Kelly, M. J.; Chambers, J. J.; Klein, T. M.; Parsons, G. N.

    2002-05-01

    This article describes the kinetics of reactions that result in substrate consumption during formation of ultrathin transition metal oxides on silicon. Yttrium silicate films (˜40 Å) with an equivalent silicon dioxide thickness of ˜11 Å are demonstrated by physical vapor deposition (PVD) routes. Interface reactions that occur during deposition and during postdeposition treatment are observed and compared for PVD and chemical vapor deposition (CVD) yttrium oxides and CVD aluminum-oxide systems. Silicon diffusion, metal-silicon bond formation, and reactions involving hydroxides are proposed as critical processes in interface layer formation. For PVD of yttrium silicate, oxidation is thermally activated with an effective barrier of 0.3 eV, consistent with the oxidation of silicide being the rate-limited step. For CVD aluminum oxide, interface oxidation is consistent with a process limited by silicon diffusion into the deposited oxide layer.

  12. Laser and electron beams physical analyses applied to the comparison between two silver tetradrachm greek coins

    Science.gov (United States)

    Torrisi, L.; Mondio, G.; Mezzasalma, A. M.; Margarone, D.; Caridi, F.; Serafino, T.; Torrisi, A.

    2009-08-01

    Physical analyses by laser ablation coupled to mass quadrupole spectrometry (LAMQS), energy dispersive X-ray fluorescence (EDX) induced by electron beam, scanning electron microscopy (SEM) and surface profilometry analysis (SPA) are applied to the investigation of two silver tetradrachms from Messana, in order to compare their elemental composition and structure. Quantitative analysis of the elemental composition and of the silver isotopic ratios have been carried out analyzing the surface patina of the two samples. Significant differences in the sulfur, chlorine and copper content, in the isotopic ratios and in the morphological aspects have been measured. The obtained results are presented and discussed from the point of view of the physical techniques useful to establish the differences between apparently true and false coins.

  13. Physical meaning of the radial index of Laguerre-Gauss beams

    Science.gov (United States)

    Plick, William N.; Krenn, Mario

    2015-12-01

    The Laguerre-Gauss modes are a class of fundamental and well-studied optical fields. These stable shape-invariant photons, exhibiting circular-cylindrical symmetry, are familiar from laser optics, micromechanical manipulation, quantum optics, communication, and foundational studies in both classical optics and quantum physics. They are characterized, chiefly, by two mode numbers: the azimuthal index indicating the orbital angular momentum of the beam, which itself has spawned a burgeoning and vibrant subfield, and the radial index, which up until recently has largely been ignored. In this paper we develop a differential operator formalism for dealing with the radial modes in both the position and momentum representations and, more importantly, give the meaning of this quantum number in terms of a well-defined physical parameter: the intrinsic hyperbolic momentum charge.

  14. Physical meaning of the radial index of Laguerre-Gauss beams

    CERN Document Server

    Plick, William N

    2016-01-01

    The Laguerre-Gauss modes are a class of fundamental and well-studied optical fields. These stable, shape-invariant photons - exhibiting circular-cylindrical symmetry - are familiar from laser optics, micro-mechanical manipulation, quantum optics, communication, and foundational studies in both classical optics and quantum physics. They are characterized, chiefly, by two modes numbers: the azimuthal index indicating the orbital angular momentum of the beam - which itself has spawned a burgeoning and vibrant sub-field - and the radial index, which up until recently, has largely been ignored. In this manuscript we develop a differential operator formalism for dealing with the radial modes in both the position and momentum representations, and - more importantly - give for the first time the meaning of this quantum number in terms of a well-defined physical parameter: the "intrinsic hyperbolic momentum charge".

  15. EBIT - Electronic Beam Ion Trap: N Divison experimental physics annual report 1995

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, D. [ed.

    1996-10-01

    The multi-faceted research effort of the EBIT (Electron Beam Ion Trap) program in N-Division of the Physics and Space Technology Department at Lawrence Livermore National Laboratory (LLNL) continues to contribute significant results to the physical sciences from studies with low energy very highly charged heavy ions. The EBIT program attracts a number of collaborators from the US and abroad for the different projects. The collaborations are partly carried out through participating graduate students demonstrating the excellent educational capabilities at the LLNL EBIT facilities. Moreover, participants from Historically Black Colleges and Universities are engaged in the EBIT project. This report describes EBIT work for 1995 in atomic structure measurements and radiative transition probabilities, spectral diagnostics for laboratory and astrophysical plasmas, ion/surface interaction studies, electron-ion interactions studies, retrap and ion collisions, and instrumental development.

  16. High Power Molten Targets for Radioactive Ion Beam Production: from Particle Physics to Medical Applications

    CERN Document Server

    De Melo Mendonca, T M

    2014-01-01

    Megawatt-class molten targets, combining high material densities and good heat transfer properties are being considered for neutron spallation sources, neutrino physics facilities and radioactive ion beam production. For this last category of facilities, in order to cope with the limitation of long diffusion times affecting the extraction of short-lived isotopes, a lead-bismuth eutectic (LBE) target loop equipped with a diffusion chamber has been proposed and tested offline during the EURISOL design study. To validate the concept, a molten LBE loop is now in the design phase and will be prototyped and tested on-line at CERN-ISOLDE. This concept was further extended to an alternative route to produce 1013 18Ne/s for the Beta Beams, where a molten salt loop would be irradiated with 7 mA, 160 MeV proton beam. Some elements of the concept have been tested by using a molten fluoride salt static unit at CERNISOLDE. The investigation of the release and production of neon isotopes allowed the measurement of the diffu...

  17. Nuclear Physics Programs for the Future Rare Isotope Beams Accelerator Facility in Korea

    CERN Document Server

    Moon, Chang-Bum

    2016-01-01

    We present nuclear physics programs based on the planned experiments using rare isotope beams (RIBs) for the future Korean Rare Isotope Beams Accelerator facility; RAON. This ambitious facility has both an Isotope Separation On Line (ISOL) and fragmentation capability for producing RIBs and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. Low energy RIBs at Elab = 5 to 20 MeV per nucleon are for the study of nuclear structure and nuclear astrophysics toward and beyond the drip lines while higher energy RIBs produced by in-flight fragmentation with the re-accelerated ions from the ISOL enable to explore the neutron drip lines in intermediate mass regions. The planned programs have goals for investigating nuclear structures of the exotic nuclei toward and beyond the nucleon drip lines by addressing the following issues: how the shell structure evolves in areas of extreme proton to neutron imbalance; whether the isospin symmetry maintains in isobaric mirror nu...

  18. Physics Potential of SPS Upgrade in regard to Beta/EC Beams

    CERN Document Server

    Bernabeu, J; Bernabéu, José; Espinoza, Catalina

    2007-01-01

    The goal for future neutrino facilities is the determination of the $[U_{e3}]$ mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source. With this objective the creation of neutrino beams from the radioactive decay of boosted ions by the SPS of CERN from either beta or electron capture transitions has been propossed. We discuss the capabilities of such facilities as a function of the energy of the boost and the baseline for the detector. We conclude that the SPS upgrade to 1000 GeV is crucial to have a better sensitivity to CP violation if it is accompanied by a longer baseline. We compare the physics potential for two different configurations. In the case of beta beams, with the same boost for both $\\beta^+$ (neutrinos) and $\\beta^-$ (antineutrinos), the two setups are: I) $\\gamma=120$, L=130 Km (Frejus); II) $\\gamma=330$, L=650 Km (Canfranc). In the case of monochromatic EC beams we exploit the energy dependence of neutrino oscillations to...

  19. Dosimetric study of RapidArc plans with flattened beam (FB and flattening filter-free (FFF beam for localized prostate cancer based on physical indices

    Directory of Open Access Journals (Sweden)

    Birendra Kumar Rout

    2014-12-01

    Full Text Available Purpose: To identify the continual diversity between flattening photon beam (FB and Flattening Filter Free (FFF photon beams for localized prostate cancer; and to determine potential benefits and drawbacks of using unflattened beam for this type of treatment.Methods: Eight prostate cases including seminal vesicles selected for this study. The primary planning target volume (PTVP and boost planning target volume (PTVB were contoured. The total prescription dose was 78 Gy (56 Gy to PTVP and an additional 22 Gy to PTVB. For all cases, treatment plans using 6MV with FB and FFF beams with identical dose-volume constraints, arc angles and number of arcs were developed. The dose volume histograms for both techniques were compared for primary target volume and critical structures.Results: A low Sigma index (FFF: 1.65 + 0.361; FB: 1.725 + 0.39 indicating improved dose homogeneity in FFF beam. Conformity index (FFF: 0.994 + 0.01; FB: 0.993 + 0.01 is comparable for both techniques. Minimal difference of Organ at risk mean dose was observed. Normal tissue integral dose in FB plan resulted 1.5% lower than FFF plan. All the plans displayed significant increase (1.18 times for PTVP and 1.11 for PTBB in the average number of necessary MU with FFF beam.Conclusion: Diversity between FB and FFF beam plans were found. FFF beam accelerator has been utilized to develop clinically acceptable Rapid Arc treatment plans for prostate cancer with 6 MV.---------------------------------Cite this article as: Rout BK, Muralidhar KR, Ali M, Shekar MC, Kumar A. Dosimetric study of RapidArc plans with flattened beam (FB and flattening filter-free (FFF beam for localized prostate cancer based on physical indices. Int J Cancer Ther Oncol 2014; 2(4:02046.  DOI: 10.14319/ijcto.0204.6

  20. Two-photon physics and online beam monitoring using the DELPHI detector at LEP

    International Nuclear Information System (INIS)

    This thesis is based on work done during 1989-1993 using the DELPHI detector at LEP, which is summarized in five articles. It consists of three main parts. The first part describes the Very Small Angle Tagger (VSAT), which is a sub-detector of the DELPHI detector at LEP. It consists of four silicon-tungsten electromagnetic calorimeter modules having a silicon strip planes for position determination. The modules are placed adjacent to the beam pipe, at ±7.7 m from the interaction point and after superconducting quadrupole magnets, allowing the detection of electrons in a polar angle range of 4 to 13 mrad. The second part is devoted to two-photon physics at DELPHI, with strong emphasis on a VSAT single-tagged event analysis. Here is shown, for the first time, evidence of hard scattering processes in single-tagged two-photon collisions. A QCD Resolved Photon Contribution (QCD-RPC) model is introduced. Data is then seen to be well described by a full VDM+(QCD-RPC) model. Different parton density functions are compared with data. The third part first describes the system for online monitoring of LEP beam background and luminosity at the DELPHI interaction point. Details are given of contributing sub-detector signals and program structure. Then follows a description of the VSAT online monitoring program (VSAT-MONITOR). A good agreement is found between the VSAT-MONITOR estimates of luminosity and beam spot and those of other detectors. Finally, results are presented of VSAT measurements of a LEP beam separation scan. 75 refs, figs

  1. Studying wedge factors and beam profiles for physical and enhanced dynamic wedges

    Directory of Open Access Journals (Sweden)

    Ahmad Misbah

    2010-01-01

    Full Text Available This study was designed to investigate variation in Varian′s Physical and Enhanced Dynamic Wedge Factors (WF as a function of depth and field size. The profiles for physical wedges (PWs and enhanced dynamic wedges (EDWs were also measured using LDA-99 array and compared for confirmation of EDW angles at different depths and field sizes. WF measurements were performed in water phantom using cylindrical 0.66 cc ionization chamber. WF was measured by taking the ratio of wedge and open field ionization data. A normalized wedge factor (NWF was introduced to circumvent large differences between wedge factors for different wedge angles. A strong linear dependence of PW Factor (PWF with depth was observed. Maximum variation of 8.9% and 4.1% was observed for 60° PW with depth at 6 and 15 MV beams respectively. The variation in EDW Factor (EDWF with depth was almost negligible and less than two per cent. The highest variation in PWF as a function of field size was 4.1% and 3.4% for thicker wedge (60° at 6 and 15 MV beams respectively and decreases with decreasing wedge angle. EDWF shows strong field size dependence and significant variation was observed for all wedges at both photon energies. Differences in profiles between PW and EDW were observed on toe and heel sides. These differences were dominant for larger fields, shallow depths, thicker wedges and low energy beam. The study indicated that ignoring depth and field size dependence of WF may result in under/over dose to the patient especially doing manual point dose calculation.

  2. Optical and structural properties of microcrystalline GaN on an amorphous substrate prepared by a combination of molecular beam epitaxy and metal–organic chemical vapor deposition

    Science.gov (United States)

    Min, Jung-Wook; Hwang, Hyeong-Yong; Kang, Eun-Kyu; Park, Kwangwook; Kim, Ci-Hyun; Lee, Dong-Seon; Jho, Young-Dahl; Bae, Si-Young; Lee, Yong-Tak

    2016-05-01

    Microscale platelet-shaped GaN grains were grown on amorphous substrates by a combined epitaxial growth method of molecular beam epitaxy (MBE) and metal–organic chemical vapor deposition (MOCVD). First, MBE GaN was grown on an amorphous substrate as a pre-orienting layer and its structural properties were investigated. Second, MOCVD grown GaN samples using the different growth techniques of planar and selective area growth (SAG) were comparatively investigated by transmission electron microscopy (TEM), cathodoluminescence (CL), and photoluminescence (PL). In MOCVD planar GaN, strong bound exciton peaks dominated despite the high density of the threading dislocations (TDs). In MOCVD SAG GaN, on the other hand, TDs were clearly reduced with bending, but basal stacking fault (BSF) PL peaks were observed at 3.42 eV. The combined epitaxial method not only provides a deep understanding of the growth behavior but also suggests an alternative approach for the growth of GaN on amorphous substances.

  3. Preconcentration, speciation and determination of ultra trace amounts of mercury by modified octadecyl silica membrane disk/electron beam irradiation and cold vapor atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ashkenani, Hamid [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of); Dadfarnia, Shayessteh [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of)], E-mail: sdadfarnia@yazduni.ac.ir; Shabani, Ali Mohammad Haji; Jaffari, Abbas Ali [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of); Behjat, Abbas [Department of physics, Yazd University, Yazd (Iran, Islamic Republic of)

    2009-01-15

    Mercury (II) and methyl mercury cations at the Sub-ppb level were adsorbed quantitatively from aqueous solution onto an octadecyl-bonded silica membrane disk modified by 2-[(2-mercaptophyenylimino)methyl] phenol (MPMP). The trapped mercury was then eluted with 3 ml ethanol and Hg{sup 2+} ion was directly measured by cold vapor atomic absorption spectrometry, utilizing tin (II) chloride. Total mercury (Hgt) was determined after conversion of MeHg{sup +} into Hg{sup 2+} ion by electron beam irradiation. A sample volume of 1500 ml resulted in a preconcentration factor of 500 and the precision for a sampling volume of 500 ml at a concentration of 2.5 {mu}g l{sup -1} (n = 7) was 3.1%. The limit of detection of the proposed method is 3.8 ng l{sup -1}. The method was successfully applied to analysis of water samples, and the accuracy was assessed via recovery experiment.

  4. A photoluminescence comparison of CdTe thin films grown by molecular-beam epitaxy, metalorganic chemical vapor deposition, and sputtering in ultrahigh vacuum

    Science.gov (United States)

    Feng, Z. C.; Bevan, M. J.; Krishnaswamy, S. V.; Choyke, W. J.

    1988-09-01

    High perfection CdTe thin films have been grown on (001) InSb and CdTe substrates by molecular-beam epitaxy, metalorganic chemical vapor deposition (MOCVD), and sputtering in ultrahigh vacuum techniques. The quality of the as-grown CdTe films are characterized by 2-K photoluminescence. The spectra show strong and sharp exciton transitions and weak 1.40-1.50-eV defect-related bands. Radiative defect densities of lower than 0.002 are realized. High-resolution spectroscopy shows that the full width at half maximum of the principal bound exciton lines is about 0.1 meV. Such small ρ values and narrow photoluminescence lines have not been previously reported. The largest luminescence efficiency is observed for MOCVD-CdTe films grown on CdTe substrates. A variety of impurities appear to be responsible for the observed radiative transitions in these three kinds of CdTe films. We attempt to assign the observed impurity related lines by a comparison with ``known'' impurities in bulk CdTe spectra given in the literature.

  5. Effects of a high magnetic field on structure evolution and properties of the molecular beam vapor deposited Fe60Ni40 nanoparticles thin films

    International Nuclear Information System (INIS)

    The Fe60Ni40 (in atomic %) nanoparticles (NPs) thin films with 90 nm thickness were prepared on 25 and 400 °C quartz substrates by using the molecular beam vapor deposition (MBVD) method under a 6 T high magnetic field (HMF). The effects of a HMF on the structure evolution and properties of Fe–Ni thin films were studied by using X-ray diffraction, atomic force microscopy, transmission electron microscopy, vibrating sample magnetometer and four-point probe method. The results show that the crystallinity of thin films is enhanced by a 6 T HMF, and a 6 T HMF changes phase composition of thin films on 25 °C substrate. It is found that the nanoparticle size decreases; the nanoparticle size distribution becomes narrow, and the root mean square (rms) roughness of thin films decreases under a 6 T HMF relative to that without HMF. These lead to the decrease of coercive force, and the increase of in-plane remanence ratio under a 6 T HMF

  6. Optical and Structural Properties of Microcrystalline GaN on an Amorphous Substrate Prepared by a Combination of Molecular Beam Epitaxy and Metal-Organic Chemical Vapor Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jung-Wook; Hwang, Hyeong-Yong; Kang, Eun-Kyu; Park, Kwangwook; Kim, Ci-Hyun; Lee, Dong-Seon; Jho, Young-Dahl; Bae, Si-Young; Lee, Yong-Tak

    2016-05-01

    Microscale platelet-shaped GaN grains were grown on amorphous substrates by a combined epitaxial growth method of molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). First, MBE GaN was grown on an amorphous substrate as a pre-orienting layer and its structural properties were investigated. Second, MOCVD grown GaN samples using the different growth techniques of planar and selective area growth (SAG) were comparatively investigated by transmission electron microscopy (TEM), cathodoluminescence (CL), and photoluminescence (PL). In MOCVD planar GaN, strong bound exciton peaks dominated despite the high density of the threading dislocations (TDs). In MOCVD SAG GaN, on the other hand, TDs were clearly reduced with bending, but basal stacking fault (BSF) PL peaks were observed at 3.42 eV. The combined epitaxial method not only provides a deep understanding of the growth behavior but also suggests an alternative approach for the growth of GaN on amorphous substances.

  7. Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University

    International Nuclear Information System (INIS)

    Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free Electron Laser for Peking University. It is the upgrade of PKU facility, which is under construction. With ERL, this facility can work in CW mode, so it can operate high average beam current without RF power constraint in main linac and generate high average FEL power. Moreover, it provides a test facility to study the key technology in ERL. System parameters are optimized for PKU ERL-FEL. The oscillation FEL output power is studied with different bunch charge, transverse emittance, bunch length and energy spread. The theory of optimal RF power and Qext with ERL and without ERL is analyzed and applied to PKU injector and linac including microphonic effect. pace charge effect in the injector and merger is studied for beam energy

  8. Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guimei [Peking Univ., Beijing (China)

    2011-12-31

    Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free Electron Laser for Peking University. It is the upgrade of PKU facility, which is under construction. With ERL, this facility can work in CW mode, so it can operate high average beam current without RF power constraint in main linac and generate high average FEL power. Moreover, it provides a test facility to study the key technology in ERL. System parameters are optimized for PKU ERL-FEL. The oscillation FEL output power is studied with different bunch charge, transverse emittance, bunch length and energy spread. The theory of optimal RF power and Q{sub ext} with ERL and without ERL is analyzed and applied to PKU injector and linac including microphonic effect. pace charge effect in the injector and merger is studied for beam

  9. Experimental and modeling studies of the hybrid physical-chemical vapor deposition of superconducting magnesium diboride thin films

    Science.gov (United States)

    Lamborn, Daniel Ray

    MgB2, with a Tc of 39 K, is a promising material for superconducting electronics and high field magnet applications. The development of deposition processes for MgB2 has been hampered by the unusually high Mg overpressure required for phase stability at elevated temperatures. Hybrid physical-chemical vapor deposition (HPCVD), a process developed at Penn State, combines thermal decomposition of B2H6 gas with an evaporative Mg flux to deposit MgB2 and is able to provide sufficient Mg overpressure for high temperature MgB2 growth. The HPCVD process does, however, have limitations arising from the original reactor configuration. The substrate and Mg supply are heated on the same inductively heated susceptor, which prevents independent temperature control and limits both the size of substrates and the amount of Mg available for growth. This in turn limits the usable range of deposition parameters such as substrate temperature and restricts the growth time which is problematic for thick films and coatings. The goals of this study were to develop an improved understanding of the HPCVD deposition process and design a new HPCVD reactor that addresses and improves upon the limitations of the original configuration. A combination of computational fluid dynamics simulations and growth experiments were used to study the HPCVD process in the original reactor. A transport and chemistry model for the growth of boron films from B2H6 was developed and used to evaluate new reactor configurations. The simple chemistry model consists of the gas-phase decomposition of B2H6 to BH 3, the adsorption of BH3 onto an activated site to form a BH2-Site complex and the transformation of the complex into a boron film and the growth rates from this model were in quantitative agreement with experimental data. A vertical dual-heater reactor configuration which was interchangeable with the original configuration was then developed to provide independent temperature control of the substrate and Mg

  10. Effect of solid-state polymerization on crystal morphology of a type of polydiacetylene single crystal obtained by physical vapor transport technique

    International Nuclear Information System (INIS)

    The effect of solid-state polymerization on the crystal morphology of a type of polydiacetylene single crystal grown by the physical vapor transport technique was experimentally investigated by optical microscopy and atomic force microscopy. The formation of backbone chains along the [001] direction was unequivocally confirmed by our experimental results. The specific cleavage characteristics of the polydiacetylene single crystal were confirmed to be strongly affected by a morphological change due to solid-state polymerization. - Highlights: • Anisotropic cleavage character • Surface roughness due to irradiation of ultra-violet rays • Verification of backbone chain direction

  11. Annual report 2011. Institute of Ion Beam Physics and Materials Research

    International Nuclear Information System (INIS)

    The first year of membership of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) in the Helmholtz Association of German Research Centers (HGF) was a year of many changes also for the Institute of Ion Beam Physics and Materials Research (IIM). The transition period, however, is not yet over, since the full integration of the Center into the HGF will only be completed in the next period of the so-called program-oriented funding (POF). This funding scheme addresses the six core research fields identified by the Helmholtz Association (Energy; Earth and Environment; Health; Key Technologies; Structure of Matter; Aeronautics, Space and Transport) to deal with the grand challenges faced by society, science and industry. Since the Institute has strong contributions to both core fields ''Key Technologies'' and ''Structure of Matter'', intense discussions were held amongst the leading scientists of the Institute, across the Institutes of the HZDR, and finally with leading scientists of other Helmholtz centers, to determine the most appropriate classification of the Institute's research. At the end we decided to establish ourselves in Structure of Matter, the core field in which most of the large-scale photon, neutron and ion facilities in Germany are located. As a consequence, the Ion Beam Center (IBC) of the Institute submitted an application to become a HGF recognized large-scale facility, providing more than 50% of its available beam time to external users. This application perfectly reflects the development of the IBC over more than a decade as a European Union funded infrastructure in the framework of the projects ''Center for Application of Ion Beams in Materials Research (AIM)'' (1998-2000, 2000-2003, 2006-2010) and subsequently as the coordinator of the integrated infrastructure initiative (I3) ''Support of Public and Industrial Research using Ion Beam Technology (SPIRIT)'' (2009-2013). Another part of the Institute's activities is dedicated to exploit the infrared

  12. Annual report 2011. Institute of Ion Beam Physics and Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, A.L.; Fassbender, J.; Heera, V.; Helm, M. (eds.)

    2012-08-22

    The first year of membership of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) in the Helmholtz Association of German Research Centers (HGF) was a year of many changes also for the Institute of Ion Beam Physics and Materials Research (IIM). The transition period, however, is not yet over, since the full integration of the Center into the HGF will only be completed in the next period of the so-called program-oriented funding (POF). This funding scheme addresses the six core research fields identified by the Helmholtz Association (Energy; Earth and Environment; Health; Key Technologies; Structure of Matter; Aeronautics, Space and Transport) to deal with the grand challenges faced by society, science and industry. Since the Institute has strong contributions to both core fields ''Key Technologies'' and ''Structure of Matter'', intense discussions were held amongst the leading scientists of the Institute, across the Institutes of the HZDR, and finally with leading scientists of other Helmholtz centers, to determine the most appropriate classification of the Institute's research. At the end we decided to establish ourselves in Structure of Matter, the core field in which most of the large-scale photon, neutron and ion facilities in Germany are located. As a consequence, the Ion Beam Center (IBC) of the Institute submitted an application to become a HGF recognized large-scale facility, providing more than 50% of its available beam time to external users. This application perfectly reflects the development of the IBC over more than a decade as a European Union funded infrastructure in the framework of the projects ''Center for Application of Ion Beams in Materials Research (AIM)'' (1998-2000, 2000-2003, 2006-2010) and subsequently as the coordinator of the integrated infrastructure initiative (I3) ''Support of Public and Industrial Research using Ion Beam Technology (SPIRIT)'' (2009

  13. Physics with fast molecular-ion beams. Proceedings of workshop held at Argonne National Laboratory, August 20-21, 1979

    International Nuclear Information System (INIS)

    The Workshop on Physics with Fast Molecular-Ion Beams was held in the Physics Division, Argonne National Laboratory on August 20 and 21, 1979. The meeting brought together representatives from several groups studying the interactions of fast (MeV) molecular-ion beams with matter. By keeping the Workshop program sharply focussed on current work related to the interactions of fast molecular ions, it was made possible for the participants to engage in vigorous and detailed discussions concerning such specialized topics as molecular-ion dissociation and transmission, wake effects, ionic charge states, cluster stopping powers, beam-foil spectroscopy, electron-emissions studies with molecular-ion beams, and molecular-ion structure determinations

  14. Analysis of a Beam Made of Physical Nonlinear Material on Nonlinear Elastic Foundation under a Moving Concentrated Load

    Directory of Open Access Journals (Sweden)

    E. Mardani

    2008-01-01

    Full Text Available A prismatic beam made of a behaviorally nonlinear material was analyzed under a concentrated load moving with a known velocity on a nonlinear elastic foundation with a reaction the vibration equation of motion was derived using Hamilton principle and Euler Lagrange equation. The amplitude of vibration, circular frequency, bending moment, stress and deflection of the beam can be calculated by the presented solution. Considering the response of the beam, in the sense of its resonance, it was found that there is no critical velocity when the behavior of the beam and foundation material is assumed to be physically nonlinear and there are finite values for the deflection, stress and bending moment of the beam when

  15. Study on application of the physical detection methods for electron beam-irradiated agricultural products

    International Nuclear Information System (INIS)

    Physical detection methods, photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) were applied to detect electron beam-irradiated agricultural products, such as red pepper, black pepper, raisin, walnut, beef seasoning and pistachio. The absorbed irradiation doses for representative samples were controlled at 0, 1, 3, 5 and 10 kGy. PSL values for non-irradiated samples were 1) except beef seasoning, whereas those of irradiated samples were more than 5,000 photon counts, upper threshold (T2) in black pepper, raisin, and beef seasoning and intermediates values of T1-T2 in red pepper, walnut, and pistachio. Minerals separated from the samples for TL measurement showed that non-irradiated samples except pistachio (TL ratio, 0.12) were characterized by no glow curves situated at temperature range of 50 ∼ 400 .deg. C with TL ratio (0.01 ∼ 0.08), while irradiated samples except pistachio at only 1 kGy (TL ratio, 0.08) indicated glow curve at about 150 ∼ 250 .deg. C with TL ratio (0.28 ∼ 3.10). ESR measurements of irradiated samples any specific signals to irradiation. The samples of both red pepper ad pistachio were produced specific signals derived from cellulose radicals as well as single line signals for black pepper and walnut, and multiple signals derived from crystalline sugar radicals for raisin and beef seasoning. In conclusion, The ESR methods can apply for detection of pistachio exposed to electron beam but PSL and TL are not suitable methods. Furthermore, TL and ESR suggested that both techniques were more useful detection method than PSL to confirm whether red pepper, walnut and beef seasoning samples have been exposed to electron beam

  16. Distinguishing new physics scenarios at a linear collider with polarized beams

    International Nuclear Information System (INIS)

    Numerous non-standard dynamics are described by contact-like effective interactions that can manifest themselves only through deviations of the cross sections from the Standard Model predictions. If one such deviation were observed, it should be important to definitely identify, to a given confidence level, the actual source among the possible non-standard interactions that in principle can explain it. We here estimate the 'identification' reach on different New Physics effective interactions obtainable from angular distributions of lepton pair production processes at the planned International Linear Collider with polarized beams. The models for which we discuss the range in the relevant high mass scales where they can be 'identified' as sources of corrections from the Standard Model predictions, are the interactions based on gravity in large and in TeV-1 extra dimensions and the compositeness-inspired four-fermion contact interactions. The availability of both beams polarized in many cases plays an essential role in enhancing the identification sensitivity. (author)

  17. Physics and Beam Monitoring with Forward Shower Counters (FSC) in CMS

    CERN Document Server

    Bell, Alan James; Hall-Wilton, Richard; Veres, Gabor Istvan; Khoze, Valery; Albrow, Michael; Mokhov, Nikolai; Rakhno, Igor; Brucken, Erik; Lamsa, Jerry; Lauhakangas, Rauno; Orava, Risto; Debbins, Paul; Norbeck, Edwin; Onel, Yasar; Schmidt, Ianos; Grachov, Oleg; Murray, Michael; Gronberg, Jeffrey; Hollar, Jonathan; Snow, Gregory R; Sobol, Andrei; Samoylenko, Vladimir; Penzo, Aldo

    2010-01-01

    We propose to add forward shower counters, FSC, to CMS along the beam pipes, with 59 m $\\lesssim z \\lesssim$ 140 m. These will detect showers from very forward particles with $7 \\lesssim \\eta \\lesssim 11$ interacting in the beam pipe and surrounding material. They increase the total rapidity coverage of CMS to nearly $\\Delta\\Omega = 4\\pi$, thus detecting most of the inelastic cross section $\\sigma_{inel}$, including low mass diffraction. They will help increase our understanding of all high cross section processes, which is important for understanding the ``underlying event'' backgrounds to most physics searches. To the extent that the luminosity is well known, they may (together with all of CMS) provide the best measurement of $\\sigma_{inel}$ at the LHC. They are most useful when the luminosity per bunch crossing is still low enough to provide single (no pile-up) collisions. They will allow measurements of single diffraction: $p+p\\rightarrow p \\oplus X$ (where $\\oplus$ means a rapidity gap) for lower mass...

  18. U.S. Heavy Ion Beam Research for High Energy Density Physics Applications and Fusion

    International Nuclear Information System (INIS)

    Key scientific results from recent experiments, modeling tools, and heavy ion accelerator research are summarized that explore ways to investigate the properties of high energy density matter in heavy-ion-driven targets, in particular, strongly-coupled plasmas at 0.01 to 0.1 times solid density for studies of warm dense matter, which is a frontier area in high energy density physics. Pursuit of these near-term objectives has resulted in many innovations that will ultimately benefit heavy ion inertial fusion energy. These include: neutralized ion beam compression and focusing, which hold the promise of greatly improving the stage between the accelerator and the target chamber in a fusion power plant; and the Pulse Line Ion Accelerator (PLIA), which may lead to compact, low-cost modular linac drivers

  19. In Bern high-energy physics shares proton beams with the hospital

    CERN Document Server

    CERN Bulletin

    2011-01-01

    A joint venture bringing together public institutions and private companies is building a new facility on the campus of Inselspital, Bern’s university hospital. The facility will host a cyclotron for the production of radiopharmaceuticals for use in PET as well as in multidisciplinary research laboratories for the development of new products for medical imaging. The Laboratory for High Energy Physics (LHEP) of Bern University, which is deeply involved in the project, will have access to a dedicated beam line and specialized labs.     Construction of the new facility is ongoing at Bern's University Hospital, where the cyclotron will be installed.   The first Bern Cyclotron symposium will take place on 6 and 7 June this year. The event is being organised by LHEP in collaboration with Bern’s Inselspital and will bring together experts – including several from CERN – to promote research activities at the new Bern Cyclotron Laboratory. &ld...

  20. Physics of ion beam cancer therapy: a multi-scale approach

    CERN Document Server

    Solov'yov, Andrey V; Scifoni, Emanuele; Mishustin, Igor; Grainer, Walter

    2008-01-01

    We propose a multi-scale approach to understand the physics related to ion-beam cancer therapy. It allows the calculation of the probability of DNA damage as a result of irradiation of tissues with energetic ions, up to 430 MeV/u. This approach covers different scales, starting from the large scale, defined by the ion stopping, followed by a smaller scale, defined by secondary electrons and radicals, and ending with the shortest scale, defined by interactions of secondaries with the DNA. We present calculations of the probabilities of single and double strand breaks of DNA, suggest a way to further expand such calculations, and also make some estimates for glial cells exposed to radiation.

  1. US heavy ion beam research for high energy density physics applications and fusion

    International Nuclear Information System (INIS)

    Key scientific results from recent experiments, modeling tools, and heavy ion accelerator research are summarized that explore ways to investigate the properties of high energy density matter in heavy-ion-driven targets, in particular, strongly-coupled plasmas at 0.01 to 0.1 times solid density for studies of warm dense matter, which is a frontier area in high energy density physics. Pursuit of these near-term objectives has resulted in many innovations that will ultimately benefit heavy ion inertial fusion energy. These include: neutralized ion beam compression and focusing, which hold the promise of greatly improving the stage between the accelerator and the target chamber in a fusion power plant; and the Pulse Line Ion Accelerator (PLIA), which may lead to compact, low-cost modular linac drivers. (authors)

  2. Synthesis of in-plane and stacked graphene/hexagonal boron nitride heterostructures by combining with ion beam sputtering deposition and chemical vapor deposition

    Science.gov (United States)

    Meng, Jun Hua; Zhang, Xing Wang; Wang, Hao Lin; Ren, Xi Biao; Jin, Chuan Hong; Yin, Zhi Gang; Liu, Xin; Liu, Heng

    2015-09-01

    Graphene/hexagonal boron nitride (h-BN) heterostructures have attracted a great deal of attention in recent years due to their unique and complementary properties for use in a wide range of potential applications. However, it still remains a challenge to synthesize large-area high quality samples by a scalable growth method. In this work, we present the synthesis of both in-plane and stacked graphene/h-BN heterostructures on Cu foils by sequentially depositing h-BN via ion beam sputtering deposition (IBSD) and graphene with chemical vapor deposition (CVD). Due to a significant difference in the growth rate of graphene on h-BN and Cu, the in-plane graphene/h-BN heterostructures were rapidly formed on h-BN domain/Cu substrates. The large-area vertically stacked graphene/h-BN heterostructures were obtained by using the continuous h-BN film as a substrate. Furthermore, the well-designed sub-bilayered h-BN substrates provide direct evidence that the monolayered h-BN on Cu exhibits higher catalytic activity than the bilayered h-BN on Cu. The growth method applied here may have great potential in the scalable preparation of large-area high-quality graphene/h-BN heterostructures.Graphene/hexagonal boron nitride (h-BN) heterostructures have attracted a great deal of attention in recent years due to their unique and complementary properties for use in a wide range of potential applications. However, it still remains a challenge to synthesize large-area high quality samples by a scalable growth method. In this work, we present the synthesis of both in-plane and stacked graphene/h-BN heterostructures on Cu foils by sequentially depositing h-BN via ion beam sputtering deposition (IBSD) and graphene with chemical vapor deposition (CVD). Due to a significant difference in the growth rate of graphene on h-BN and Cu, the in-plane graphene/h-BN heterostructures were rapidly formed on h-BN domain/Cu substrates. The large-area vertically stacked graphene/h-BN heterostructures were

  3. Annual report 2012. Institute of Ion Beam Physics and Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, A.L.; Fassbender, J.; Heera, V.; Helm, M. (eds.)

    2013-09-01

    In 2012 the HZDR, and in consequence also the Institute of Ion Beam Physics and Materials Research (IIM) including its Ion Beam Center (IBC), has undergone a scientific evaluation. The evaluation committee composed of the Scientific Advisory Board and numerous external experts in our field of research concluded that ''the overall quality of the scientific work is excellent'', that ''there are an impressive number of young scientists working enthusiastically on a variety of high-level projects'' and that ''the choice of these projects represents a clear underlying strategy and vision''. We feel honored and are proud that the external view on our scientific achievements is that extraordinary. In view of this outstanding result we would like to express our gratitude to all our staff members for their commitment and efforts. In the past year, we continued our integration into the Helmholtz Association of German Research Centers (HGF) with our Institute mostly active in the research area ''Matter'', but also involved in a number of activities in the research area ''Energy''. In this respect, many consultations were held with the Helmholtz centers contributing to common research areas to precisely define the role we will play in the newly established HGF program ''From Matter to Materials and Life''. Our IBC has been recognized as a large-scale user facility for ion beam analysis and modification of materials, i.e., specializing on materials science. In particular, the IBC plays a prominent role in the recently approved Helmholtz Energy Materials Characterization Platform (HEMCP), which mainly concentrates on the development of dedicated analytical tools for the characterization of materials required for future energy technologies. The successes achieved by the IBC allows us to invest 7200 kEuro to further improve and strengthen the ion beam

  4. Technical Challenges and Scientific Payoffs of Muon Beam Accelerators for Particle Physics

    International Nuclear Information System (INIS)

    Historically, progress in particle physics has largely been determined by development of more capable particle accelerators. This trend continues today with the recent advent of high-luminosity electron-positron colliders at KEK and SLAC operating as 'B factories', the imminent commissioning of the Large Hadron Collider at CERN, and the worldwide development effort toward the International Linear Collider. Looking to the future, one of the most promising approaches is the development of muon-beam accelerators. Such machines have very high scientific potential, and would substantially advance the state-of-the-art in accelerator design. A 20-50 GeV muon storage ring could serve as a copious source of well-characterized electron neutrinos or antineutrinos (a Neutrino Factory), providing beams aimed at detectors located 3000-7500 km from the ring. Such long baseline experiments are expected to be able to observe and characterize the phenomenon of charge-conjugation-parity (CP) violation in the lepton sector, and thus provide an answer to one of the most fundamental questions in science, namely, why the matter-dominated universe in which we reside exists at all. By accelerating muons to even higher energies of several TeV, we can envision a Muon Collider. In contrast with composite particles like protons, muons are point particles. This means that the full collision energy is available to create new particles. A Muon Collider has roughly ten times the energy reach of a proton collider at the same collision energy, and has a much smaller footprint. Indeed, an energy frontier Muon Collider could fit on the site of an existing laboratory, such as Fermilab or BNL. The challenges of muon-beam accelerators are related to the facts that (1) muons are produced as a tertiary beam, with very large 6D phase space, and (2) muons are unstable, with a lifetime at rest of only 2 microseconds. How these challenges are accommodated in the accelerator design will be described. Both a

  5. Annual report 2012. Institute of Ion Beam Physics and Materials Research

    International Nuclear Information System (INIS)

    In 2012 the HZDR, and in consequence also the Institute of Ion Beam Physics and Materials Research (IIM) including its Ion Beam Center (IBC), has undergone a scientific evaluation. The evaluation committee composed of the Scientific Advisory Board and numerous external experts in our field of research concluded that ''the overall quality of the scientific work is excellent'', that ''there are an impressive number of young scientists working enthusiastically on a variety of high-level projects'' and that ''the choice of these projects represents a clear underlying strategy and vision''. We feel honored and are proud that the external view on our scientific achievements is that extraordinary. In view of this outstanding result we would like to express our gratitude to all our staff members for their commitment and efforts. In the past year, we continued our integration into the Helmholtz Association of German Research Centers (HGF) with our Institute mostly active in the research area ''Matter'', but also involved in a number of activities in the research area ''Energy''. In this respect, many consultations were held with the Helmholtz centers contributing to common research areas to precisely define the role we will play in the newly established HGF program ''From Matter to Materials and Life''. Our IBC has been recognized as a large-scale user facility for ion beam analysis and modification of materials, i.e., specializing on materials science. In particular, the IBC plays a prominent role in the recently approved Helmholtz Energy Materials Characterization Platform (HEMCP), which mainly concentrates on the development of dedicated analytical tools for the characterization of materials required for future energy technologies. The successes achieved by the IBC allows us to invest 7200 kEuro to further improve and strengthen the ion beam capabilities at the Institute. In addition to this infrastructure-related grant, we were also successful in our funding application

  6. Physics opportunities of a fixed-target experiment using LHC beams

    Science.gov (United States)

    Brodsky, S. J.; Fleuret, F.; Hadjidakis, C.; Lansberg, J. P.

    2013-01-01

    We outline the many physics opportunities offered by a multi-purpose fixed-target experiment using the proton and lead-ion beams of the LHC extracted by a bent crystal. In a proton run with the LHC 7 TeV beam, one can analyze pp, pd and pA collisions at center-of-mass energy √{s}≃115 GeV and even higher using the Fermi motion of the nucleons in a nuclear target. In a lead run with a 2.76 TeV-per-nucleon beam, √{s} is as high as 72 GeV. Bent crystals can be used to extract about 5×108 protons/s; the integrated luminosity over a year reaches 0.5 fb-1 on a typical 1 cm long target without nuclear species limitation. We emphasize that such an extraction mode does not alter the performance of the collider experiments at the LHC. By instrumenting the target-rapidity region, gluon and heavy-quark distributions of the proton and the neutron can be accessed at large x and even at x larger than unity in the nuclear case. Single diffractive physics and, for the first time, the large negative-xF domain can be accessed. The nuclear target-species versatility provides a unique opportunity to study nuclear matter versus the features of the hot and dense matter formed in heavy-ion collisions, including the formation of the quark-gluon plasma, which can be studied in PbA collisions over the full range of target-rapidity domain with a large variety of nuclei. The polarization of hydrogen and nuclear targets allows an ambitious spin program, including measurements of the QCD lensing effects which underlie the Sivers single-spin asymmetry, the study of transversity distributions and possibly of polarized parton distributions. We also emphasize the potential offered by pA ultra-peripheral collisions where the nucleus target A is used as a coherent photon source, mimicking photoproduction processes in ep collisions. Finally, we note that W and Z bosons can be produced and detected in a fixed-target experiment and in their threshold domain for the first time, providing new ways to

  7. Plasma-Enhanced Chemical Vapor Deposition (PE-CVD) yields better Hydrolytical Stability of Biocompatible SiOx Thin Films on Implant Alumina Ceramics compared to Rapid Thermal Evaporation Physical Vapor Deposition (PVD).

    Science.gov (United States)

    Böke, Frederik; Giner, Ignacio; Keller, Adrian; Grundmeier, Guido; Fischer, Horst

    2016-07-20

    Densely sintered aluminum oxide (α-Al2O3) is chemically and biologically inert. To improve the interaction with biomolecules and cells, its surface has to be modified prior to use in biomedical applications. In this study, we compared two deposition techniques for adhesion promoting SiOx films to facilitate the coupling of stable organosilane monolayers on monolithic α-alumina; physical vapor deposition (PVD) by thermal evaporation and plasma enhanced chemical vapor deposition (PE-CVD). We also investigated the influence of etching on the formation of silanol surface groups using hydrogen peroxide and sulfuric acid solutions. The film characteristics, that is, surface morphology and surface chemistry, as well as the film stability and its adhesion properties under accelerated aging conditions were characterized by means of X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and tensile strength tests. Differences in surface functionalization were investigated via two model organosilanes as well as the cell-cytotoxicity and viability on murine fibroblasts and human mesenchymal stromal cells (hMSC). We found that both SiOx interfaces did not affect the cell viability of both cell types. No significant differences between both films with regard to their interfacial tensile strength were detected, although failure mode analyses revealed a higher interfacial stability of the PE-CVD films compared to the PVD films. Twenty-eight day exposure to simulated body fluid (SBF) at 37 °C revealed a partial delamination of the thermally deposited PVD films whereas the PE-CVD films stayed largely intact. SiOx layers deposited by both PVD and PE-CVD may thus serve as viable adhesion-promoters for subsequent organosilane coupling agent binding to α-alumina. However, PE-CVD appears to be favorable for long-term direct film exposure to aqueous

  8. Effect of basic physical parameters to control plasma meniscus and beam halo formation in negative ion sources

    International Nuclear Information System (INIS)

    Our previous study shows that the curvature of the plasma meniscus causes the beam halo in the negative ion sources: the negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. In this article, the detail physics of the plasma meniscus and beam halo formation is investigated with two-dimensional particle-in-cell simulation. It is shown that the basic physical parameters such as the H− extraction voltage and the effective electron confinement time significantly affect the formation of the plasma meniscus and the resultant beam halo since the penetration of electric field for negative ion extraction depends on these physical parameters. Especially, the electron confinement time depends on the characteristic time of electron escape along the magnetic field as well as the characteristic time of electron diffusion across the magnetic field. The plasma meniscus penetrates deeply into the source plasma region when the effective electron confinement time is short. In this case, the curvature of the plasma meniscus becomes large, and consequently the fraction of the beam halo increases

  9. Development and Application of High Energy Ion Beam Methods in Tandetron Laboratory of Nuclear Physics Institute of ASCR

    Czech Academy of Sciences Publication Activity Database

    Macková, Anna; Malinský, Petr; Havránek, Vladimír

    Bucharest: EuNPC, 2012, s. 97-97. [2nd European Nuclear Physics Conference - EuNPC 2012. Bucharest (RO), 16.09.2012-21.09.2012] R&D Projects: GA MŠk LM2011019; GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : ion beam analytical metods * RBS * ERDA Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  10. First implementation of transversely split proton beams in the CERN Proton Synchrotron for the fixed-target physics programme

    CERN Document Server

    Borburgh, J; Gilardoni, S; Giovannozzi, M; Hernalsteens, C; Hourican, M; Huschauer, A; Kahle, K; Le Godec, G; Michels, O; Sterbini, G

    2016-01-01

    A new extraction technique has been studied at the CERN Proton Synchrotron with a view of using it for the fixed-target physics programme at the Super Proton Synchrotron. The extraction scheme is based on advanced concepts of non-linear beam dynamics: prior to extraction a particle beam is split into several beamlets in a transverse plane by crossing a stable resonance, which allows extracting the beamlets over multiple turns. The principle of the extraction, the detail of its implementation, and the progress of the beam commissioning over the years are discussed here. More importantly, the results obtained during the first period of successful use for the physics programme are presented, focusing on the performance analysis of the novel extraction.

  11. Metallic impurity-activated crystal growth of boron phosphide by chemical vapor deposition and its physical properties

    International Nuclear Information System (INIS)

    Needle single crystals of boron monophosphide as large as 5 - 100 μm in diameter and 4 mm in length were obtained by chemical vapor deposition on an impurity painted zone of quartz substrate at 1060 - 1120 0C. The impurities such as Mn, Ni, Pt, Ag or Au were painted on the substrate in a form of aqueous solution of their salts and decomposed or reduced to the respective metal in hydrogen atmosphere at 10000C. Needle crystals with the homo p-n junction were also prepared using Ni impurity. The colors of grown crystals varied with the change of gas composition. Differences of electrical resistivity and thermoelectric power were found between the crystals of different colors. (auth.)

  12. High throughput production of nanocomposite SiO x powders by plasma spray physical vapor deposition for negative electrode of lithium ion batteries

    Directory of Open Access Journals (Sweden)

    Keiichiro Homma

    2014-04-01

    Full Text Available Nanocomposite Si/SiO x powders were produced by plasma spray physical vapor deposition (PS-PVD at a material throughput of 480 g h−1. The powders are fundamentally an aggregate of primary ~20 nm particles, which are composed of a crystalline Si core and SiO x shell structure. This is made possible by complete evaporation of raw SiO powders and subsequent rapid condensation of high temperature SiO x vapors, followed by disproportionation reaction of nucleated SiO x nanoparticles. When CH4 was additionally introduced to the PS-PVD, the volume of the core Si increases while reducing potentially the SiO x shell thickness as a result of the enhanced SiO reduction, although an unfavorable SiC phase emerges when the C/Si molar ratio is greater than 1. As a result of the increased amount of Si active material and reduced source for irreversible capacity, half-cell batteries made of PS-PVD powders with C/Si = 0.25 have exhibited improved initial efficiency and maintenance of capacity as high as 1000 mAh g−1 after 100 cycles at the same time.

  13. High throughput production of nanocomposite SiO x powders by plasma spray physical vapor deposition for negative electrode of lithium ion batteries

    International Nuclear Information System (INIS)

    Nanocomposite Si/SiO x powders were produced by plasma spray physical vapor deposition (PS-PVD) at a material throughput of 480 g h−1. The powders are fundamentally an aggregate of primary ∼20 nm particles, which are composed of a crystalline Si core and SiO x shell structure. This is made possible by complete evaporation of raw SiO powders and subsequent rapid condensation of high temperature SiO x vapors, followed by disproportionation reaction of nucleated SiO x nanoparticles. When CH4 was additionally introduced to the PS-PVD, the volume of the core Si increases while reducing potentially the SiO x shell thickness as a result of the enhanced SiO reduction, although an unfavorable SiC phase emerges when the C/Si molar ratio is greater than 1. As a result of the increased amount of Si active material and reduced source for irreversible capacity, half-cell batteries made of PS-PVD powders with C/Si = 0.25 have exhibited improved initial efficiency and maintenance of capacity as high as 1000 mAh g−1 after 100 cycles at the same time. (papers)

  14. Physical performance and image optimization of megavoltage cone-beam CT

    International Nuclear Information System (INIS)

    Megavoltage cone-beam CT (MVCBCT) is the most recent addition to the in-room CT systems developed for image-guided radiation therapy. The first generation MVCBCT system consists of a 6 MV treatment x-ray beam produced by a conventional linear accelerator equipped with a flat panel amorphous silicon detector. The objective of this study was to evaluate the physical performance of MVCBCT in order to optimize the system acquisition and reconstruction parameters for image quality. MVCBCT acquisitions were performed with the clinical system but images were reconstructed and analyzed with a separate research workstation. The geometrical stability and the positioning accuracy of the system were evaluated by comparing geometrical calibrations routinely performed over a period of 12 months. The beam output and detector intensity stability during MVCBCT acquisition were also evaluated by analyzing in-air acquisitions acquired at different exposure levels. Several system parameters were varied to quantify their impact on image quality including the exposure (2.7, 4.5, 9.0, 18.0, and 54.0 MU), the craniocaudal imaging length (2, 5, 15, and 27.4 cm), the voxel size (0.5, 1, and 2 mm), the slice thickness (1, 3, and 5 mm), and the phantom size. For the reconstruction algorithm, the study investigated the effect of binning, averaging and diffusion filtering of raw projections as well as three different projection filters. A head-sized water cylinder was used to measure and improve the uniformity of MVCBCT images. Inserts of different electron densities were placed in a water cylinder to measure the contrast-to-noise ratio (CNR). The spatial resolution was obtained by measuring the point-spread function of the system using an iterative edge blurring technique. Our results showed that the geometric stability and accuracy of MVCBCT were better than 1 mm over a period of 12 months. Beam intensity variations per projection of up to 35.4% were observed for a 2.7 MU MVCBCT acquisition

  15. From neutrino physics to beam polarisation. A high precision story at the ILC

    International Nuclear Information System (INIS)

    In this thesis, we investigate the experimental prospects of studying a supersymmetric model with bilinearly broken R parity at the International Linear Collider. In this model, neutrinos mix with the supersymmetric neutralinos such that neutrino properties can be probed by examining neutralino decays, which incorporate usually a lepton and a W/Z boson. As a study case, we focus on the determination of the atmospheric neutrino mixing angle θ23, which is accessible via the ratio of the neutralino branching ratios BR(χ01→Wμ)/BR(χ01→Wτ). A detailed simulation of the International Large Detector has been performed for all Standard Model backgrounds and for χ01-pair production within a simplified model. The study is based on ILC beam parameters according to the Technical Design Report for a center-of-mass energy of √(s)=500 GeV. From muonic χ01 decays, we find that the χ01 mass can be reconstructed with an uncertainty of δ(mχ01)=(40(stat.)+35(syst.)) MeV for an integrated luminosity of ∫Ldt=500 fb-1. The ratio of branching ratios can be determined to a precision of δ(BR(χ01→Wμ)/BR(χ01→Wτ))=2.9%. Due to this, the atmospheric neutrino mixing angle can be deduced with a precision comparable to modern neutrino experiments. Thus, the ILC is capable to test whether bRPV SUSY is the mechanism of neutrino mass generation. As also shown in the bRPV SUSY study of this thesis, beam polarisation is an important parameter in physics analyses at the ILC. The beam polarisation is measured with two Compton polarimeters per electron/positron beam. In order to achieve the design goal of an envisaged precision of 0.25%, the detector nonlinearity of the used Cherenkov detectors has to be determined very precisely. Herein, the main source of nonlinearity is expected to originate from the involved photomultipliers. For this reason, a differential nonlinearity measurement as well as a linearisation method is developed. The working principle is demonstrated in a

  16. Physical performance and image optimization of megavoltage cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Morin, Olivier; Aubry, Jean-Francois; Aubin, Michele; Chen, Josephine; Descovich, Martina; Hashemi, Ali-Bani; Pouliot, Jean [Department of Radiation Oncology, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California 94143 and UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158 (United States); Department of Radiation Oncology, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California 94143 (United States); Siemens Oncology Care Systems, Concord, California 94520 (United States); Department of Radiation Oncology, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, California 94143 and UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158 (United States)

    2009-04-15

    Megavoltage cone-beam CT (MVCBCT) is the most recent addition to the in-room CT systems developed for image-guided radiation therapy. The first generation MVCBCT system consists of a 6 MV treatment x-ray beam produced by a conventional linear accelerator equipped with a flat panel amorphous silicon detector. The objective of this study was to evaluate the physical performance of MVCBCT in order to optimize the system acquisition and reconstruction parameters for image quality. MVCBCT acquisitions were performed with the clinical system but images were reconstructed and analyzed with a separate research workstation. The geometrical stability and the positioning accuracy of the system were evaluated by comparing geometrical calibrations routinely performed over a period of 12 months. The beam output and detector intensity stability during MVCBCT acquisition were also evaluated by analyzing in-air acquisitions acquired at different exposure levels. Several system parameters were varied to quantify their impact on image quality including the exposure (2.7, 4.5, 9.0, 18.0, and 54.0 MU), the craniocaudal imaging length (2, 5, 15, and 27.4 cm), the voxel size (0.5, 1, and 2 mm), the slice thickness (1, 3, and 5 mm), and the phantom size. For the reconstruction algorithm, the study investigated the effect of binning, averaging and diffusion filtering of raw projections as well as three different projection filters. A head-sized water cylinder was used to measure and improve the uniformity of MVCBCT images. Inserts of different electron densities were placed in a water cylinder to measure the contrast-to-noise ratio (CNR). The spatial resolution was obtained by measuring the point-spread function of the system using an iterative edge blurring technique. Our results showed that the geometric stability and accuracy of MVCBCT were better than 1 mm over a period of 12 months. Beam intensity variations per projection of up to 35.4% were observed for a 2.7 MU MVCBCT acquisition

  17. From neutrino physics to beam polarisation. A high precision story at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Vormwald, Benedikt

    2014-03-15

    In this thesis, we investigate the experimental prospects of studying a supersymmetric model with bilinearly broken R parity at the International Linear Collider. In this model, neutrinos mix with the supersymmetric neutralinos such that neutrino properties can be probed by examining neutralino decays, which incorporate usually a lepton and a W/Z boson. As a study case, we focus on the determination of the atmospheric neutrino mixing angle θ{sub 23}, which is accessible via the ratio of the neutralino branching ratios BR(χ{sup 0}{sub 1}→Wμ)/BR(χ{sup 0}{sub 1}→Wτ). A detailed simulation of the International Large Detector has been performed for all Standard Model backgrounds and for χ{sup 0}{sub 1}-pair production within a simplified model. The study is based on ILC beam parameters according to the Technical Design Report for a center-of-mass energy of √(s)=500 GeV. From muonic χ{sup 0}{sub 1} decays, we find that the χ{sup 0}{sub 1} mass can be reconstructed with an uncertainty of δ(m{sub χ{sup 0}{sub 1}})=(40(stat.)+35(syst.)) MeV for an integrated luminosity of ∫Ldt=500 fb{sup -1}. The ratio of branching ratios can be determined to a precision of δ(BR(χ{sup 0}{sub 1}→Wμ)/BR(χ{sup 0}{sub 1}→Wτ))=2.9%. Due to this, the atmospheric neutrino mixing angle can be deduced with a precision comparable to modern neutrino experiments. Thus, the ILC is capable to test whether bRPV SUSY is the mechanism of neutrino mass generation. As also shown in the bRPV SUSY study of this thesis, beam polarisation is an important parameter in physics analyses at the ILC. The beam polarisation is measured with two Compton polarimeters per electron/positron beam. In order to achieve the design goal of an envisaged precision of 0.25%, the detector nonlinearity of the used Cherenkov detectors has to be determined very precisely. Herein, the main source of nonlinearity is expected to originate from the involved photomultipliers. For this reason, a differential

  18. High quality MgB2 thick films and large-area films fabricated by hybrid physical chemical vapor deposition with a pocket heater

    Science.gov (United States)

    Wang, S. F.; Chen, Ke; Lee, C.-H.; Soukiassian, A.; Lamborn, D. R.; DeFrain, R.; Redwing, J. M.; Li, Qi; Schlom, D. G.; Xi, X. X.

    2008-08-01

    A hybrid physical-chemical vapor deposition process using a pocket heater was developed for the growth of high quality epitaxial large-area MgB2 thin films and c-axis textured MgB2 thick films. This technique is able to independently control the substrate and Mg source temperatures and maintain sufficient Mg overpressure to ensure phase stability. The two-inch large-area MgB2 thin films showed uniform superconducting properties with the superconducting transition temperature Tc of about 40 K, residual resistivity ratio (RRR) of about 10, and critical current density Jc of about 107 A cm-2 (0 T, 5 K). The thick films (~10 µm) on sapphire substrates showed a maximum Tc of 40 K and RRR of 15, and a Jc of 1.6 × 106 A cm-2 at low applied magnetic fields even at 20 K. High quality thick films also have been obtained on metal substrates.

  19. Physics with gamma-beams and charged particle detectors: I) Nuclear structure II) Nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Gai, Moshe [LNS at Avery Point, University of Connecticut, Groton, CT 06340-6097, USA and Wright Lab, Dept. of Physics, Yale University, New Haven, CT 06520-8124 and the Charged Particle Working Group (CPWG) of the Technical Design Report (TDR) (United States)

    2015-02-24

    The Charged Particle Working Group (CPWG) is proposing to construct large area Silicon Strip Detector (SSD), a gas Time Projection Chamber detector read by an electronic readout system (eTPC) and a Bubble Chamber (BC) containing superheated high purity water to be used in measurements utilizing intense gamma-ray beams from the newly constructed ELI-NP facility at Magurele, Bucharest in Romania. We intend to use the SSD and eTPC detectors to address essential problems in nuclear structure physics, such as clustering and the many alpha-decay of light nuclei such as {sup 12}C and {sup 16}O. All three detectors (SSD, eTPC and BC) will be used to address central problems in nuclear astrophysics such as the astrophysical cross section factor of the {sup 12}C(α,γ) reaction and other processes central to stellar evolution. The CPWG intends to submit to the ELI-NP facility a Technical Design Report (TDR) for the proposed detectors.

  20. Quarkonium Physics at a Fixed-Target Experiment using the LHC Beams

    CERN Document Server

    Lansberg, J P; Fleuret, F; Hadjidakis, C

    2012-01-01

    We outline the many quarkonium-physics opportunities offered by a multi-purpose fixed-target experiment using the p and Pb LHC beams extracted by a bent crystal. This provides an integrated luminosity of 0.5 fb-1 per year on a typical 1cm-long target. Such an extraction mode does not alter the performance of the collider experiments at the LHC. With such a high luminosity, one can analyse quarkonium production in great details in pp, pd and pA collisions at sqrt(sNN)~115 GeV and at sqrt(sNN)~72 GeV in PbA collisions. In a typical pp (pA) run, the obtained quarkonium yields per unit of rapidity are 2-3 orders of magnitude larger than those expected at RHIC and about respectively 10 (70) times larger than for ALICE. In PbA, they are comparable. By instrumenting the target-rapidity region, the large negative-xF domain can be accessed for the first time, greatly extending previous measurements by Hera-B and E866. Such analyses should help resolving the quarkonium-production controversies and clear the way for glu...

  1. Future directions in particle and nuclear physics at multi-GeV hadron beam facilities

    Energy Technology Data Exchange (ETDEWEB)

    Geesaman, D.F. [Argonne National Lab., IL (United States)] [ed.

    1993-11-01

    This report contains papers on the following topics in particle and nuclear physics: hadron dynamics; lepton physics; spin physics; hadron and nuclear spectroscopy; hadronic weak interactions; and Eta physics. These papers have been indexed separately elsewhere.

  2. Future directions in particle and nuclear physics at multi-GeV hadron beam facilities

    International Nuclear Information System (INIS)

    This report contains papers on the following topics in particle and nuclear physics: hadron dynamics; lepton physics; spin physics; hadron and nuclear spectroscopy; hadronic weak interactions; and Eta physics. These papers have been indexed separately elsewhere

  3. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71

    International Nuclear Information System (INIS)

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D0′, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D0′ = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D0′ ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of dm, with D0′ = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism

  4. Physical properties of nitrogen-doped diamond-like amorphous carbon films deposited by supermagnetron plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Diamond-like amorphous carbon films doped with nitrogen (DAC:N) were deposited on Si and glass wafers intermittently using i-C4H10/N2 repetitive supermagnetron plasma chemical vapor deposition. Deposition duration, which is equal to a plasma heating time of wafer, was selected to be 40 or 60 s, and several layers were deposited repetitively to form one thick film. DAC:N films were deposited at a lower-electrode temperature of 100 deg. C as a function of upper- and lower-electrode rf powers (200 W/200 W-1 kW/1 kW) and N2 concentration (0%-80%). With an increase in N2 concentration and rf power, the resistivity and the optical band gap decreased monotonously. With increase of the deposition duration from 40 to 60 s, resistivity decreased to 0.03Ω cm and optical band gap decreased to 0.02 eV (substantially equal to 0 eV within the range of experimental error), at an N2 concentration of 80% and rf power of 1 kW(/1 kW)

  5. Physical and Electrical Characteristics of Carbon Nanotube Network Field-Effect Transistors Synthesized by Alcohol Catalytic Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Chin-Lung Cheng

    2011-01-01

    Full Text Available Carbon nanotubes (CNTs have been explored in nanoelectronics to realize desirable device performances. Thus, carbon nanotube network field-effect transistors (CNTNFETs have been developed directly by means of alcohol catalytic chemical vapor deposition (ACCVD method using Co-Mo catalysts in this work. Various treated temperatures, growth time, and Co/Mo catalysts were employed to explore various surface morphologies of carbon nanotube networks (CNTNs formed on the SiO2/n-type Si(100 stacked substrate. Experimental results show that most semiconducting single-walled carbon nanotube networks with 5–7 nm in diameter and low disorder-induced mode (D-band were grown. A bipolar property of CNTNFETs synthesized by ACCVD and using HfO2 as top-gate dielectric was demonstrated. Various electrical characteristics, including drain current versus drain voltage (Id-Vd, drain current versus gate voltage (Id-Vg, mobility, subthreshold slope (SS, and transconductance (Gm, were obtained.

  6. Accelerator physics studies on the effects from an asynchronous beam dump onto the LHC experimental region collimators

    CERN Document Server

    Lari, L; Boccone, V; Bruce, R; Cerutti, F; Rossi, A; Vlachoudis, V; Mereghetti, A; Faus-Golfe, A

    2012-01-01

    Asynchronous beam aborts at the LHC are estimated to occur on average once per year. Accelerator physics studies of asynchronous dumps have been performed at different beam energies and beta-stars. The loss patterns are analyzed in order to identify the losses in particular on the Phase 1 Tertiary Collimators (TCT), since their tungsten-based active jaw insert has a lower damage threshold than the carbon-based other LHC collimators. Settings of the tilt angle of the TCTs are discussed with the aim of reducing the thermal loads on the TCT themselves.

  7. Theory and Simulation of the Physics of Space Charge Dominated Beams

    International Nuclear Information System (INIS)

    This report describes modeling of intense electron and ion beams in the space charge dominated regime. Space charge collective modes play an important role in the transport of intense beams over long distances. These modes were first observed in particle-in-cell simulations. The work presented here is closely tied to the University of Maryland Electron Ring (UMER) experiment and has application to accelerators for heavy ion beam fusion

  8. Review of neutral beam heating on JET for physics experiments and the production of high fusion performance plasmas

    International Nuclear Information System (INIS)

    The JET neutral beam injection system has proved to be both effective and reliable as a plasma heating device. The ion heating and plasma fuelling characteristics of the system are ideally suited to the production of high fusion performance plasmas while the flexibility in the choice of beam species (H, D, T, 3He or 4He) and the ability to inject into almost any JET plasma configuration allows a wide variety of related physics experiments to be carried out. The capability to inject (for the first time) tritium beams was essential to the successful execution of the first tritium experiments in which 1.7MW of power from D-T fusion reactions was generated. ((orig.))

  9. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.  Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish how ready we are to do physics with the early collisions at the LHC. The agenda of the week was thus pac...

  10. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.   Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish (we hoped) the readiness of CMS to do physics with the early collisions at the LHC. The agenda of the...

  11. Quarkonium Physics at a Fixed-Target Experiment using the LHC Beams

    International Nuclear Information System (INIS)

    We outline the many quarkonium-physics opportunities offered by a multi-purpose fixed-target experiment using the p and Pb Large Hadron Collider (LHC) beams extracted by a bent crystal. This provides an integrated luminosity of 0. 5 fb-1 per year on a typical 1 cm-long target. Such an extraction mode does not alter the performance of the collider experiments at the LHC. With such a high luminosity, one can analyse quarkonium production in great details in pp, pd and pA collisions at √sNN≅115 GeV and at √sNN≅72 GeV in PbA collisions. In a typical pp (pA) run, the obtained quarkonium yields per unit of rapidity are 2-3 orders of magnitude larger than those expected at RHIC and about, respectively, 10(70) times larger than for ALICE. In PbA, they are comparable. By instrumenting the target-rapidity region, the large negative-x F domain can be accessed for the first time, greatly extending previous measurements by Hera-B and E866. Such analyses should help resolving the quarkonium-production controversies and clear the way for gluon PDF extraction via quarkonium studies. The nuclear target-species versatility provides a unique opportunity to study nuclear matter and the features of the hot and dense matter formed in PbA collisions. A polarised proton target allows the study of transverse-spin asymmetries in J/ψ and Y production, providing access to the gluon and charm Sivers functions. (author)

  12. Physical properties of electron beam evaporated CdTe and CdTe:Cu thin films

    International Nuclear Information System (INIS)

    In this paper, we report on physical properties of pure and Cu doped cadmium telluride (CdTe) films deposited onto corning 7059 microscopic glass substrates by electron beam evaporation technique. X-ray diffraction study showed that all the deposited films belong to amorphous nature. The average transmittance of the films is varied between 77% and 90%. The optical energy band gap of pure CdTe film is 1.57 eV and it decreased to 1.47 eV upon 4 wt. % of Cu addition, which may be due to the extension of localized states in the band structure. The refractive index of the films was calculated using Swanepoel method. It was observed that the dispersion data obeyed the single oscillator of the Wemple-Didomenico model, from which the dispersion energy (Ed) parameters, dielectric constants, plasma frequency, and oscillator energy (Eo) of CdTe and CdTe:Cu films were calculated and discussed in detail with the light of possible mechanisms underlying the phenomena. The variation in intensity of photoluminescence band edge emission peak observed at 820 nm with Cu dopant is due to the change in surface state density. The observed trigonal lattice of Te peaks in the micro-Raman spectra confirms the p-type conductive nature of films, which was further corroborated by the Hall effect measurement. The lowest resistivity of 6.61 × 104 Ω cm was obtained for the CdTe:Cu (3 wt. %) film

  13. Quarkonium Physics at a Fixed-Target Experiment Using the LHC Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lansberg, J.P.; /Orsay, IPN; Brodsky, S.J.; /SLAC; Fleuret, F.; /Ecole Polytechnique; Hadjidakis, C.; /Orsay, IPN

    2012-04-09

    We outline the many quarkonium-physics opportunities offered by a multi-purpose fixed-target experiment using the p and Pb LHC beams extracted by a bent crystal. This provides an integrated luminosity of 0.5 fb{sup -1} per year on a typical 1cm-long target. Such an extraction mode does not alter the performance of the collider experiments at the LHC. With such a high luminosity, one can analyse quarkonium production in great details in pp, pd and pA collisions at {radical}s{sub NN} {approx_equal} 115 GeV and at {radical}s{sub NN} {approx_equal} 72 GeV in PbA collisions. In a typical pp (pA) run, the obtained quarkonium yields per unit of rapidity are 2-3 orders of magnitude larger than those expected at RHIC and about respectively 10 (70) times larger than for ALICE. In PbA, they are comparable. By instrumenting the target-rapidity region, the large negative-x{sub F} domain can be accessed for the first time, greatly extending previous measurements by Hera-B and E866. Such analyses should help resolving the quarkonium-production controversies and clear the way for gluon PDF extraction via quarkonium studies. The nuclear target-species versatility provides a unique opportunity to study nuclear matter and the features of the hot and dense matter formed in PbA collisions. A polarised proton target allows the study of transverse-spin asymmetries in J/{Psi} and {Upsilon} production, providing access to the gluon and charm Sivers functions.

  14. Forschungszentrum Rossendorf, Institute of Ion Beam Physics and Materials Research. Annual report 2004

    International Nuclear Information System (INIS)

    The following topics are dealt with: Silicon based electrically driven microcavity LED, ultraviolet electroluminescence from a Gd-implanted Si-metal-oxide-semiconductor device, semiconductor quantum-cascade lasers, ion beam synthesis and morphology of semiconductor memories, ion implantation, films, sputtering, ion-beam induced destabilization of nanoparticles. (HSI)

  15. Forschungszentrum Rossendorf, Institute of Ion Beam Physics and Materials Research. Annual report 2004

    Energy Technology Data Exchange (ETDEWEB)

    Borany, J. von; Heera, V.; Helm, M.; Jaeger, H.U.; Moeller, W. (eds.)

    2005-07-01

    The following topics are dealt with: Silicon based electrically driven microcavity LED, ultraviolet electroluminescence from a Gd-implanted Si-metal-oxide-semiconductor device, semiconductor quantum-cascade lasers, ion beam synthesis and morphology of semiconductor memories, ion implantation, films, sputtering, ion-beam induced destabilization of nanoparticles. (HSI)

  16. Physical and electrochemical characterization of amorphous lithium lanthanum titanate solid electrolyte thin-film fabricated by e-beam evaporation

    International Nuclear Information System (INIS)

    Amorphous lithium lanthanum titanate (LLTO) solid electrolyte thin-films have been fabricated by e-beam evaporation. The effect of different e-beam power on the physical properties and electrical performance of LLTO thin-film is investigated. Higher e-beam power is a key factor to obtain good quality LLTO thin-film which has higher ionic conductivity. X-ray diffraction patterns, X-ray photoelectron spectra, scanning electron microscopy and impedance spectroscopy are used to characterize their physical and electrical properties. An all-solid-state of Li/LiPON/LLTO/LiCoO2 cell using LLTO thin-film as solid electrolyte exhibits the first discharge capacity of about 50 μA h/cm2-μm and the capacity fading is about 0.5% per cycles after 100 discharge-charge cycles at discharge current of 7 μA/cm2, demonstrating the promise of e-beam evaporation deposition for the fabrication of LLTO thin-film for all-solid-state thin-film rechargeable lithium batteries

  17. Physical and electrochemical characterization of amorphous lithium lanthanum titanate solid electrolyte thin-film fabricated by e-beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Li Chilin [Department of Chemistry and Laser Chemistry Institute, Shanghai Key laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433 (China); Zhang Bin [Department of Chemistry and Laser Chemistry Institute, Shanghai Key laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433 (China); Fu Zhengwen [Department of Chemistry and Laser Chemistry Institute, Shanghai Key laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433 (China)]. E-mail: zhengwen@sh163.net

    2006-12-05

    Amorphous lithium lanthanum titanate (LLTO) solid electrolyte thin-films have been fabricated by e-beam evaporation. The effect of different e-beam power on the physical properties and electrical performance of LLTO thin-film is investigated. Higher e-beam power is a key factor to obtain good quality LLTO thin-film which has higher ionic conductivity. X-ray diffraction patterns, X-ray photoelectron spectra, scanning electron microscopy and impedance spectroscopy are used to characterize their physical and electrical properties. An all-solid-state of Li/LiPON/LLTO/LiCoO{sub 2} cell using LLTO thin-film as solid electrolyte exhibits the first discharge capacity of about 50 {mu}A h/cm{sup 2}-{mu}m and the capacity fading is about 0.5% per cycles after 100 discharge-charge cycles at discharge current of 7 {mu}A/cm{sup 2}, demonstrating the promise of e-beam evaporation deposition for the fabrication of LLTO thin-film for all-solid-state thin-film rechargeable lithium batteries.

  18. A geometrical and physical nonlinear finite element model for spatial thin-walled beams with arbitrary section

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the theories of Bernoulli-Euler beams and Vlasov’s thin-walled members,a new geometrical and physical nonlinear beam element model is developed by applying an interior node in the element and independent interpolations on bending angles and warp,in which factors such as traverse shear deformation,torsional shear deformation and their coupling,coupling of flexure and torsion,and second shear stress are all considered.Thereafter,geometrical nonlinear strain in total Lagarange(TL) and the corresponding stiffness matrix are formulated.Ideal plastic model is applied to physical nonlinearity to comply with the yield rule of Von Mises and incremental relationship of Prandtle-Reuss.Elastoplastic stiffness matrix is derived by numerical integration on the basis of the finite segment method.Examples show that the developed model is feasible in analysis of thin-walled structures with high accuracy.

  19. Physical principles of the surface plasma method for producing beams of negative ions

    International Nuclear Information System (INIS)

    The processes which are important for the production of intense beams of negative ions from surface plasma sources (SPS) are examined. The formation of negative ions when atomic particles interact with a surface is analyzed on the basis of both experimental results obtained when a surface was bombarded with beams and recently developed theoretical considerations of reflection, scattering, and electron exchange. The characteristic features of these processes in SPS, when a surface is bombarded with intense fluxes of plasma particles, are revealed in special experiments. The characteristics of generation and acceleration of the bombarding particles in a gas discharge SPS plasma, the characteristics of transportation of negative ions through the plasma toward the beam forming system, the role of cesium in SPS, and the characteristics of formation of the intense negative ion beams as well as the removal of parasite electrons from the beam

  20. Physics Potential of a Long Baseline Neutrino Oscillation Experiment Using J-PARC Neutrino Beam and Hyper-Kamiokande

    CERN Document Server

    Abe, K; Andreopoulos, C; Anghel, I; Ariga, A; Ariga, T; Asfandiyarov, R; Askins, M; Back, J J; Ballett, P; Barbi, M; Barker, G J; Barr, G; Bay, F; Beltrame, P; Berardi, V; Bergevin, M; Berkman, S; Berry, T; Bhadra, S; Blaszczyk, F d M; Blondel, A; Bolognesi, S; Boyd, S B; Bravar, A; Bronner, C; Cafagna, F S; Carminati, G; Cartwright, S L; Catanesi, M G; Choi, K; Choi, J H; Collazuol, G; Cowan, G; Cremonesi, L; Davies, G; De Rosa, G; Densham, C; Detwiler, J; Dewhurst, D; Di Lodovico, F; Di Luise, S; Drapier, O; Emery, S; Ereditato, A; Fernández, P; Feusels, T; Finch, A; Fitton, M; Friend, M; Fujii, Y; Fukuda, Y; Fukuda, D; Galymov, V; Ganezer, K; Gonin, M; Gumplinger, P; Hadley, D R; Haegel, L; Haesler, A; Haga, Y; Hartfiel, B; Hartz, M; Hayato, Y; Hierholzer, M; Hill, J; Himmel, A; Hirota, S; Horiuchi, S; Huang, K; Ichikawa, A K; Iijima, T; Ikeda, M; Imber, J; Inoue, K; Insler, J; Intonti, R A; Irvine, T; Ishida, T; Ishino, H; Ishitsuka, M; Itow, Y; Izmaylov, A; Jamieson, B; Jang, H I; Jiang, M; Joo, K K; Jung, C K; Kaboth, A; Kajita, T; Kameda, J; Karadhzov, Y; Katori, T; Kearns, E; Khabibullin, M; Khotjantsev, A; Kim, J Y; Kim, S B; Kishimoto, Y; Kobayashi, T; Koga, M; Konaka, A; Kormos, L L; Korzenev, A; Koshio, Y; Kropp, W R; Kudenko, Y; Kutter, T; Kuze, M; Labarga, L; Lagoda, J; Laveder, M; Lawe, M; Learned, J G; Lim, I T; Lindner, T; Longhin, A; Ludovici, L; Ma, W; Magaletti, L; Mahn, K; Malek, M; Mariani, C; Marti, L; Martin, J F; Martin, C; Martins, P P J; Mazzucato, E; McCauley, N; McFarland, K S; McGrew, C; Mezzetto, M; Minakata, H; Minamino, A; Mine, S; Mineev, O; Miura, M; Monroe, J; Mori, T; Moriyama, S; Mueller, T; Muheim, F; Nakahata, M; Nakamura, K; Nakaya, T; Nakayama, S; Needham, M; Nicholls, T; Nirkko, M; Nishimura, Y; Noah, E; Nowak, J; Nunokawa, H; O'Keeffe, H M; Okajima, Y; Okumura, K; Oser, S M; O'Sullivan, E; Ovsiannikova, T; Owen, R A; Oyama, Y; Pérez, J; Pac, M Y; Palladino, V; Palomino, J L; Paolone, V; Payne, D; Perevozchikov, O; Perkin, J D; Pistillo, C; Playfer, S; Posiadala-Zezula, M; Poutissou, J -M; Quilain, B; Quinto, M; Radicioni, E; Ratoff, P N; Ravonel, M; Rayner, M A; Redij, A; Retiere, F; Riccio, C; Richard, E; Rondio, E; Rose, H J; Ross-Lonergan, M; Rott, C; Rountree, S D; Rubbia, A; Sacco, R; Sakuda, M; Sanchez, M C; Scantamburlo, E; Scholberg, K; Scott, M; Seiya, Y; Sekiguchi, T; Sekiya, H; Shaikhiev, A; Shimizu, I; Shiozawa, M; Short, S; Sinnis, G; Smy, M B; Sobczyk, J; Sobel, H W; Stewart, T; Stone, J L; Suda, Y; Suzuki, Y; Suzuki, A T; Svoboda, R; Tacik, R; Takeda, A; Taketa, A; Takeuchi, Y; Tanaka, H A; Tanaka, H K M; Tanaka, H; Terri, R; Thompson, L F; Thorpe, M; Tobayama, S; Tolich, N; Tomura, T; Touramanis, C; Tsukamoto, T; Tzanov, M; Uchida, Y; Vagins, M R; Vasseur, G; Vogelaar, R B; Walter, C W; Wark, D; Wascko, M O; Weber, A; Wendell, R; Wilkes, R J; Wilking, M J; Wilson, J R; Xin, T; Yamamoto, K; Yanagisawa, C; Yano, T; Yen, S; Yershov, N; Yokoyama, M; Zito, M

    2015-01-01

    Hyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of $CP$ asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this paper, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis uses the framework and systematic uncertainties derived from the ongoing T2K experiment. With a total exposure of 7.5 MW $\\times$ 10$^7$ sec integrated proton beam power (corresponding to $1.56\\times10^{22}$ protons on target with a 30 GeV proton beam) to a $2.5$-degree off-axis neutrino beam, it is expected that the leptonic $CP$ phase $\\delta_{CP}$ can be determined to better than 19 degrees for all possible values of $\\delta_{CP}$, and $CP$ violation can be establis...

  1. The development of an interdepartmental audit as part of a physics quality assurance programme for external beam therapy

    International Nuclear Information System (INIS)

    A cost-effective audit system has been developed that will both detect systematic error in data and procedures, and evaluate the quality assurance programme provided by a physics department for radiotherapy. The audit has been developed for external beam radiotherapy and assesses one modality and one treatment machine per year. The method of assessing the quality assurance programme and the schedule of measurements are described. The process is illustrated using the results of trial audits between the medical physics department at Coventry and Leicester. (author)

  2. The physical characteristics of the 15 MV Varian Clinac 2100C unflattened beam

    Science.gov (United States)

    Najem, M. A.; Spyrou, N. M.; Podolyák, Z.; Abolaban, F. A.

    2014-02-01

    A 15 MV photon beam of a Varian Clinac 2100C medical linear accelerator operating with and without a flattening filter was simulated using the Monte Carlo code 'FLUKA' in order to calculate differences in their dosimetric properties. These include: the dose rate, the percentage depth dose on the central axis, the beam profile, the out-of-field dose, the surface dose on a 40×40×40 cm3 water phantom and the neutron contamination. The results obtained showed that the unflattened beam has a dose rate 4.86 times higher than the flattened one. The average out-of-field dose from the edge of the field to the edge of the phantom was reduced by 44%, the neutron fluence at the isocentre was reduced by 77% and the surface neutron dose-equivalent was reduced from 2.11±0.05 to 0.40±0.01 mSv(n) Gy-1(X) after normalising both beams to give the same dose at dmax (the depth of maximum dose). However, the photon surface dose of the unflattened beam increased by 13%. From this information, it can be concluded that the unflattened beam can lead to better treatment outcome and may reduce the beam-on time which may be required for specific cases.

  3. The physical characteristics of the 15 MV Varian Clinac 2100C unflattened beam

    International Nuclear Information System (INIS)

    A 15 MV photon beam of a Varian Clinac 2100C medical linear accelerator operating with and without a flattening filter was simulated using the Monte Carlo code ‘FLUKA’ in order to calculate differences in their dosimetric properties. These include: the dose rate, the percentage depth dose on the central axis, the beam profile, the out-of-field dose, the surface dose on a 40×40×40 cm3 water phantom and the neutron contamination. The results obtained showed that the unflattened beam has a dose rate 4.86 times higher than the flattened one. The average out-of-field dose from the edge of the field to the edge of the phantom was reduced by 44%, the neutron fluence at the isocentre was reduced by 77% and the surface neutron dose-equivalent was reduced from 2.11±0.05 to 0.40±0.01 mSv(n) Gy−1(X) after normalising both beams to give the same dose at dmax (the depth of maximum dose). However, the photon surface dose of the unflattened beam increased by 13%. From this information, it can be concluded that the unflattened beam can lead to better treatment outcome and may reduce the beam-on time which may be required for specific cases. - Highlights: • We made a Monte Carlo simulation to study the dosimetric properties of the unflattened beam of the 15 MV Varian Clinac 2100C. • Removing the flattening filter increase the dose rate of the beam. • Removing the flattening filter decrease the out-of-field dose. • Removing the flattening filter decrease the photoneutron production. • The surface dose to the patient is increased by removing the flattening filter

  4. Nonlinear physics and energetic particle transport features of the beam-plasma instability

    CERN Document Server

    Carlevaro, Nakia; Montani, Giovanni; Zonca, Fulvio

    2015-01-01

    In this paper, we study transport features of a one-dimensional beam-plasma system in the presence of multiple resonances. As a model description of the general problem of a warm energetic particle beam, we assume $n$ cold supra-thermal beams and investigate the self-consistent evolution in the presence of the complete spectrum of nearly degenerate Langmuir modes. A qualitative transport estimation is obtained by computing the Lagrangian Coherent Structures of the system on given temporal scales. This leads to the splitting of the phase space into regions where the local transport processes are relatively faster. The general theoretical framework is applied to the case of the nonlinear dynamics of two cold beams, for which numerical simulation results are illustrated and analyzed.

  5. Nonlinear physics and energetic particle transport features of the beam-plasma instability

    Science.gov (United States)

    Carlevaro, Nakia; Falessi, Matteo V.; Montani, Giovanni; Zonca, Fulvio

    2015-10-01

    > In this paper we study transport features of a one-dimensional beam-plasma system in the presence of multiple resonances. As a model description of the general problem of a warm energetic particle beam, we assume cold supra-thermal beams and investigate the self-consistent evolution in the presence of the complete spectrum of nearly degenerate Langmuir modes. A qualitative transport estimation is obtained by computing the Lagrangian Coherent Structures of the system on given temporal scales. This leads to the splitting of the phase space into regions where the local transport processes are relatively faster. The general theoretical framework is applied to the case of the nonlinear dynamics of two cold beams, for which numerical simulation results are illustrated and analysed.

  6. Radiological physics of heavy charged-particle beams used for therapy

    International Nuclear Information System (INIS)

    The beams available for biological investigations at the Bevatron or at the Bevalac range from helium to iron ions. However, only carbon, neon, and argon beams have been used for therapy. The treatment techniques are arbitrarily divided into two categories: small field and large field irradiation. Examples of the small field treatments are pituitary irradiation, which generaly utilizes the plateau portion of the helium depth-dose curve, and treatment of ocular melanoma, which uses a modified Bragg peak of the helium beam. Large field treatments for cancer therapy generally requires a beam that has a large uniform transverse profile and a modified Bragg peak. Procedures and instrumentation for patient irradiations at the Bevatron/Bevalac have been based on the prior experience obtained at the 184-inch Synchrocyclotron, and for that reason both facilities are discussed

  7. High intensity X/γ photon beams for nuclear physics and photonics

    Science.gov (United States)

    Serafini, L.; Alesini, D.; Bacci, N.; Bliss, N.; Cassou, K.; Curatolo, C.; Drebot, I.; Dupraz, K.; Giribono, A.; Petrillo, V.; Palumbo, L.; Vaccarezza, C.; Variola, A.; Zomer, F.

    2016-05-01

    In this manuscript we review the challenges of Compton backscattering sources in advancing photon beam performances in the 1 - 20 MeV energy range, underlining the design criteria bringing to maximum spectral luminosity and briefly describing the main achievements in conceiving and developing new devices (multi-bunch RF cavities and Laser recirculators) for the case of ELI-NP Gamma Beam System (ELI-NP-GBS).

  8. High intensity X/γ photon beams for nuclear physics and photonics

    Directory of Open Access Journals (Sweden)

    Serafini L.

    2016-01-01

    Full Text Available In this manuscript we review the challenges of Compton backscattering sources in advancing photon beam performances in the 1 – 20 MeV energy range, underlining the design criteria bringing to maximum spectral luminosity and briefly describing the main achievements in conceiving and developing new devices (multi-bunch RF cavities and Laser recirculators for the case of ELI-NP Gamma Beam System (ELI-NP-GBS.

  9. Short-Baseline Neutrino Physics using the NOvA Near Detector and the Booster Neutrino Beam

    Science.gov (United States)

    Dharmapalan, Ranjan

    2016-03-01

    The NOvA Near Detector (ND) is a low Z, nearly-fully active tracking detector, capable of 3D reconstruction of neutrino-induced interactions, situated at Fermilab, about 1 km from the NuMI neutrino beam target. Due to its positioning 14.6 mrad off the beam axis, the detector samples a narrow-band neutrino beam peaked at 2 GeV. NOvA's ND L/E greatly overlaps with the L/E range of the recent MiniBooNE experiment on the Booster neutrino beamline at Fermilab, thus making the NOvA ND an ideal tool to test a sterile neutrino hypothesis in this L/E regime and to study the low-energy excess reported by MiniBooNE. Due to the large off-axis angle (160 mrad) with respect to the Booster neutrino beamline, the NOvA ND will also observe high energy (1.4 GeV) kaon decay-in-flight neutrinos from the Booster neutrino beamline, at about 800 meters from the target. In addition, this unique `two beams in one detector' setup enables a cross-check of the energy calibration and of the measurement of neutrino cross sections at different neutrino energies in the same detector. We discuss physics capabilities and present sensitivity studies within such an experimental setup.

  10. Highly selective etching of silicon nitride to physical-vapor-deposited a-C mask in dual-frequency capacitively coupled CH2F2/H2 plasmas

    International Nuclear Information System (INIS)

    A multilevel resist (MLR) structure can be fabricated based on a very thin amorphous carbon (a-C) layer ( congruent with 80 nm) and Si3N4 hard-mask layer ( congruent with 300 nm). The authors investigated the selective etching of the Si3N4 layer using a physical-vapor-deposited (PVD) a-C mask in a dual-frequency superimposed capacitively coupled plasma etcher by varying the process parameters in the CH2F2/H2/Ar plasmas, viz., the etch gas flow ratio, high-frequency source power (PHF), and low-frequency source power (PLF). They found that under certain etch conditions they obtain infinitely high etch selectivities of the Si3N4 layers to the PVD a-C on both the blanket and patterned wafers. The etch gas flow ratio played a critical role in determining the process window for infinitely high Si3N4/PVD a-C etch selectivity because of the change in the degree of polymerization. The etch results of a patterned ArF photoresisit/bottom antireflective coating/SiOx/PVD a-C/Si3N4 MLR structure supported the idea of using a very thin PVD a-C layer as an etch-mask layer for the Si3N4 hard-mask pattern with a pattern width of congruent with 80 nm and high aspect ratio of congruent with 5.

  11. Fabrication of superconducting MgB2 thin films on textured Cu(100) tape by hybrid physical-chemical vapor deposition

    International Nuclear Information System (INIS)

    We report on the fabrication of superconducting MgB2 thin films on textured Cu(100) tape under low pressure and temperature by using a hybrid physical-chemical vapor deposition (HPCVD) technique to explore the possible broad range of deposition. Thermodynamic calculations for the Mg-B system have been carried out and the pressure-temperature phase diagram was obtained. Our results demonstrate that the deposition of superconducting MgB2 films is possible beyond the theoretically calculated growth window, where the sublimation of Mg is taking place. The structural and microstructural investigations reveal that MgB2 films are c-axis-oriented normal to the substrate. The highest Jc of ∼1.34 x 105 A cm-2 at 5 K under 3 T is obtained for the film grown at 460 deg. C. The critical current density (Jc) and flux pinning force density (Fp) of MgB2 films are enhanced with decreasing growth temperature. This could be attributed to the high density of grain boundaries which may act as effective flux pinning centers. These findings suggest an alternative route to fabricate MgB2 tapes at low temperature for large scale applications.

  12. High quality MgB2 thick films and large-area films fabricated by hybrid physical-chemical vapor deposition with a pocket heater

    International Nuclear Information System (INIS)

    A hybrid physical-chemical vapor deposition process using a pocket heater was developed for the growth of high quality epitaxial large-area MgB2 thin films and c-axis textured MgB2 thick films. This technique is able to independently control the substrate and Mg source temperatures and maintain sufficient Mg overpressure to ensure phase stability. The two-inch large-area MgB2 thin films showed uniform superconducting properties with the superconducting transition temperature Tc of about 40 K, residual resistivity ratio (RRR) of about 10, and critical current density Jc of about 107 A cm-2 (0 T, 5 K). The thick films (∼10 μm) on sapphire substrates showed a maximum Tc of 40 K and RRR of 15, and a Jc of 1.6 x 106 A cm-2 at low applied magnetic fields even at 20 K. High quality thick films also have been obtained on metal substrates

  13. High quality MgB{sub 2} thick films and large-area films fabricated by hybrid physical-chemical vapor deposition with a pocket heater

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S F; Chen, Ke; Li, Qi; Xi, X X [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Lee, C-H; Soukiassian, A; DeFrain, R; Redwing, J M; Schlom, D G [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Lamborn, D R [Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802 (United States)], E-mail: suw16@psu.edu

    2008-08-15

    A hybrid physical-chemical vapor deposition process using a pocket heater was developed for the growth of high quality epitaxial large-area MgB{sub 2} thin films and c-axis textured MgB{sub 2} thick films. This technique is able to independently control the substrate and Mg source temperatures and maintain sufficient Mg overpressure to ensure phase stability. The two-inch large-area MgB{sub 2} thin films showed uniform superconducting properties with the superconducting transition temperature T{sub c} of about 40 K, residual resistivity ratio (RRR) of about 10, and critical current density J{sub c} of about 10{sup 7} A cm{sup -2} (0 T, 5 K). The thick films ({approx}10 {mu}m) on sapphire substrates showed a maximum T{sub c} of 40 K and RRR of 15, and a J{sub c} of 1.6 x 10{sup 6} A cm{sup -2} at low applied magnetic fields even at 20 K. High quality thick films also have been obtained on metal substrates.

  14. Modeling studies of an impinging jet reactor design for hybrid physical-chemical vapor deposition of superconducting MgB 2 films

    Science.gov (United States)

    Lamborn, Daniel R.; Wilke, Rudeger H. T.; Li, Qi; Xi, X. X.; Snyder, David W.; Redwing, Joan M.

    2009-03-01

    An impinging jet reactor was developed for the deposition of superconducting MgB 2 thin films by hybrid physical-chemical vapor deposition, a technique that combines Mg evaporation with the thermal decomposition of B 2H 6 gas. A transport and chemistry model for boron film deposition from B 2H 6 was initially used to investigate the effect of carrier gas, Mg crucible temperature and gas flow rates on boron film growth rate and uniformity. The modeling studies, which were validated experimentally, demonstrated a reduction in B 2H 6 gas-phase depletion and an increased boron film growth rate using an argon carrier gas compared to hydrogen. The results were used to identify a suitable set of process conditions for MgB 2 deposition in the impinging jet reactor. The deposition of polycrystalline MgB 2 thin films that exhibited a transition temperature of 39.5 K was demonstrated at growth rates up to ˜50 μm/h.

  15. Effect of electron cyclotron resonance ion source frequency tuning on ion beam intensity and quality at Department of Physics, University of Jyvaeskylae

    International Nuclear Information System (INIS)

    Ion beam intensity and quality have a crucial effect on the operation efficiency of the accelerator facilities. This paper presents the investigations on the ion beam intensity and quality after the mass separation performed with the Department of Physics, University of Jyvaeskylae 14 GHz electron cyclotron resonance ion source by sweeping the microwave in the 14.05-14.13 GHz range. In many cases a clear variation in the ion beam intensity and quality as a function of the frequency was observed. The effect of frequency tuning increased with the charge state. In addition, clear changes in the beam structure seen with the beam viewer were observed. The results confirmed that frequency tuning can have a remarkable effect on ion beam intensity and quality especially in the case of highly charged ion beams. The examples presented here represent the typical charge state behavior observed during the measurements.

  16. Effect of electron cyclotron resonance ion source frequency tuning on ion beam intensity and quality at Department of Physics, University of Jyväskylä.

    Science.gov (United States)

    Toivanen, V; Koivisto, H; Steczkiewicz, O; Celona, L; Tarvainen, O; Ropponen, T; Gammino, S; Mascali, D; Ciavola, G

    2010-02-01

    Ion beam intensity and quality have a crucial effect on the operation efficiency of the accelerator facilities. This paper presents the investigations on the ion beam intensity and quality after the mass separation performed with the Department of Physics, University of Jyväskylä 14 GHz electron cyclotron resonance ion source by sweeping the microwave in the 14.05-14.13 GHz range. In many cases a clear variation in the ion beam intensity and quality as a function of the frequency was observed. The effect of frequency tuning increased with the charge state. In addition, clear changes in the beam structure seen with the beam viewer were observed. The results confirmed that frequency tuning can have a remarkable effect on ion beam intensity and quality especially in the case of highly charged ion beams. The examples presented here represent the typical charge state behavior observed during the measurements. PMID:20192340

  17. The influence of physical wedges on penumbra and in-field dose uniformity in ocular proton beams.

    Science.gov (United States)

    Baker, Colin; Kacperek, Andrzej

    2016-04-01

    A physical wedge may be partially introduced into a proton beam when treating ocular tumours in order to improve dose conformity to the distal border of the tumour and spare the optic nerve. Two unwanted effects of this are observed: a predictable broadening of the beam penumbra on the wedged side of the field and, less predictably, an increase in dose within the field along a relatively narrow volume beneath the edge (toe) of the wedge, as a result of small-angle proton scatter. Monte Carlo simulations using MCNPX and direct measurements with radiochromic (GAFCHROMIC(®) EBT2) film were performed to quantify these effects for aluminium wedges in a 60 MeV proton beam as a function of wedge angle and position of the wedge relative to the patient. For extreme wedge angles (60° in eye tissue) and large wedge-to-patient distances (70 mm in this context), the 90-10% beam penumbra increased from 1.9 mm to 9.1 mm. In-field dose increases from small-angle proton scatter were found to contribute up to 21% additional dose, persisting along almost the full depth of the spread-out-Bragg peak. Profile broadening and in-field dose enhancement are both minimised by placing the wedge as close as possible to the patient. Use of lower atomic number wedge materials such as PMMA reduce the magnitude of both effects as a result of a reduced mean scattering angle per unit energy loss; however, their larger physical size and greater variation in density are undesirable. PMID:26988936

  18. Understanding Supernova Neutrino Physics using Low-Energy Beta-Beams

    OpenAIRE

    Jachowicz, N.; McLaughlin, G.C.

    2005-01-01

    We show that fitting linear combinations of low-energy beta-beam spectra to supernova-neutrino energy-distributions reconstructs the response of a nuclear target to a supernova flux in a very accurate way. This allows one to make direct predictions about the supernova-neutrino signal in a terrestrial neutrino detector.

  19. Wavefront-sensor-induced beam size error: physical mechanism, sensitivity-analysis and correction method

    NARCIS (Netherlands)

    Koek, W.D.; Zwet, E.J. van

    2015-01-01

    When using a commonly-used quadri-wave lateral shearing interferometer wavefront sensor (QWLSI WFS) for beam size measurements on a high power CO2 laser, artefacts have been observed in the measured irradiance distribution. The grating in the QWLSI WFS not only generates the diffracted first orders

  20. Nuclear physics with simple and multi-element detectors and with stable and radioactive beams

    Indian Academy of Sciences (India)

    Neil Rowley

    2001-07-01

    The phenomenon of fusion barrier distributions is discussed in the context of a problem already investigated in some detail with simple detection systems, but possessing avenues to studies with multi-detector arrays. The complementarity of research with simple and complex detectors, as well as with stable and radioactive beams, will be highlighted.

  1. VEPP-2M new electron-positron colliding beam facility of the Siberian Institute of Nuclear Physics

    International Nuclear Information System (INIS)

    A description and results of constructing the 670 MeV VEPP-2M strong-focusing storage ring are given. The VEPP-2 is a booster where electron and positron beams are accumulated in succession and then extracted into the VEPP-2M. The VEPP-2M comprises light sections of a magentic system, four short gaps and four long ones. Three gaps, each of 650 mm long, are intended to conduct experiments on high energy physics. Present status of the VEPP-2M of 1972 is described and the program of experiments planned is presented

  2. Mathematical modeling of kinetics of volume condensation of water and sulfuric acid vapors during electron-beam purification of power plant flue gases

    International Nuclear Information System (INIS)

    The kinetic equations system, describing the volume condensation process of water and purification of power plant flue gases is developed. The role of water and sulfuric acid vapors nucleation, the drops growth on the account of H2O and H2SO4 molecule condensation thereon and drops coagulation due to their Brownian movement in the summary process is analyzed. It is shown that dissolution of other gaseous compounds (SO2, NH3, etc.) in the molecule drops may be considered in the approximation of the gas-liquid quasi-equilibrium

  3. Ion beam driven high energy density physics studies at FAIR at darmstadt: the HEDgeHOB collaboration

    International Nuclear Information System (INIS)

    High Energy Density (HED) physics spans over numerous areas of basic and applied physics, for example, astrophysics, planetary physics, geophysics, inertial fusion and many others. Due to this reason, it has been a subject of very active research over the past many decades. Static as well as dynamic methods have been applied to generate samples of HED matter in the laboratory. The most commonly used tool in the static techniques is the diamond anvil cell while the dynamic methods involve shock compression of matter. During the past fifteen years, great progress has been made on the development of bunched intense particle beams that have emerged as an additional new tool for studying HED physics. In this paper we present two experiment designs that have been worked out for HED physics studies at the Facility for Antiprotons and Ion Research (FAIR) at Darmstadt. This facility has entered into construction phase and will provide one of the largest and most powerful particle accelerators in the world. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. High Energy Density Physics Research Using Intense Heavy Ion Beam at FAIR: The HEDgeHOB Program

    Science.gov (United States)

    Tahir, N. A.; Shutov, A.; Piriz, A. R.; Deutsch, C.; Stöhlker, Th.

    2016-03-01

    International project, Facility for Antiprotons and Ion Research (FAIR), has entered in its construction phase at Darmstadt. It is expected that the new powerful heavy ion synchrotron, SIS100 will deliver a strongly bunched intense beam of energetic uranium ions that will provide the scientists with an efficient and novel tool to research High Energy Density (HED) Physics in the laboratory. Over the past 15 years, substantial theoretical work has been done to design numerous experiments that can be done at this facility in this field. This work has resulted in an extensive scientific proposal named HEDgeHOB, that includes experiment proposals addressing various aspects of HED matter, for example, planetary physics, equation of state, hydrodynamic instabilities and others. In this paper we present a summary of this work.

  5. ''Accelerators and Beams,'' multimedia computer-based training in accelerator physics

    International Nuclear Information System (INIS)

    We are developing a set of computer-based tutorials on accelerators and charged-particle beams under an SBIR grant from the DOE. These self-paced, interactive tutorials, available for Macintosh and Windows platforms, use multimedia techniques to enhance the user's rate of learning and length of retention of the material. They integrate interactive ''On-Screen Laboratories,'' hypertext, line drawings, photographs, two- and three-dimensional animations, video, and sound. They target a broad audience, from undergraduates or technicians to professionals. Presently, three modules have been published (Vectors, Forces, and Motion), a fourth (Dipole Magnets) has been submitted for review, and three more exist in prototype form (Quadrupoles, Matrix Transport, and Properties of Charged-Particle Beams). Participants in the poster session will have the opportunity to try out these modules on a laptop computer

  6. Physical vapor deposition synthesis of two-dimensional orthorhombic SnS flakes with strong angle/temperature-dependent Raman responses

    Science.gov (United States)

    Xia, Jing; Li, Xuan-Ze; Huang, Xing; Mao, Nannan; Zhu, Dan-Dan; Wang, Lei; Xu, Hua; Meng, Xiang-Min

    2016-01-01

    Anisotropic layered semiconductors have attracted significant interest due to the huge possibility of bringing new functionalities to thermoelectric, electronic and optoelectronic devices. Currently, most reports on anisotropy have concentrated on black phosphorus and ReS2, less effort has been contributed to other layered materials. In this work, two-dimensional (2D) orthorhombic SnS flakes on a large scale have been successfully synthesized via a simple physical vapor deposition method. Angle-dependent Raman spectroscopy indicated that the orthorhombic SnS flakes possess a strong anisotropic Raman response. Under a parallel-polarization configuration, the peak intensity of Ag (190.7 cm-1) Raman mode reaches the maximum when incident light polarization is parallel to the armchair direction of the 2D SnS flakes, which strongly suggests that the Ag (190.7 cm-1) mode can be used to determine the crystallographic orientation of the 2D SnS. In addition, temperature-dependent Raman characterization confirmed that the 2D SnS flakes have a higher sensitivity to temperature than graphene, MoS2 and black phosphorus. These results are useful for the future studies of the optical and thermal properties of 2D orthorhombic SnS.Anisotropic layered semiconductors have attracted significant interest due to the huge possibility of bringing new functionalities to thermoelectric, electronic and optoelectronic devices. Currently, most reports on anisotropy have concentrated on black phosphorus and ReS2, less effort has been contributed to other layered materials. In this work, two-dimensional (2D) orthorhombic SnS flakes on a large scale have been successfully synthesized via a simple physical vapor deposition method. Angle-dependent Raman spectroscopy indicated that the orthorhombic SnS flakes possess a strong anisotropic Raman response. Under a parallel-polarization configuration, the peak intensity of Ag (190.7 cm-1) Raman mode reaches the maximum when incident light polarization

  7. Wavefront-sensor-induced beam size error: physical mechanism, sensitivity-analysis and correction method

    OpenAIRE

    Koek, W.D.; Zwet, E.J. van

    2015-01-01

    When using a commonly-used quadri-wave lateral shearing interferometer wavefront sensor (QWLSI WFS) for beam size measurements on a high power CO2 laser, artefacts have been observed in the measured irradiance distribution. The grating in the QWLSI WFS not only generates the diffracted first orders that are required for introducing the shear, but also diffracts significantly into higher orders. Consequently, in the few millimeters of free space propagation between the QWLSI WFS grating and it...

  8. Ion beams: from plasma physics to applications in analysis and irradiation fields

    International Nuclear Information System (INIS)

    In this HDR (Accreditation to supervise research) report, the author proposes an overview of his research activities. A first part comments a research which aimed at determining the distribution of ion populations in an electron cyclotron resonance (ECR) plasma. Then, after a brief recall of the principles and techniques of analysis based on ion beams, he presents some characteristics of the CEA/Saclay nuclear microprobe. He reports various works related to material science and to biology, and discusses the associated perspectives

  9. 1000 MeV Proton beam therapy facility at Petersburg Nuclear Physics Institute Synchrocyclotron

    Science.gov (United States)

    Abrosimov, N. K.; Gavrikov, Yu A.; Ivanov, E. M.; Karlin, D. L.; Khanzadeev, A. V.; Yalynych, N. N.; Riabov, G. A.; Seliverstov, D. M.; Vinogradov, V. M.

    2006-05-01

    Since 1975 proton beam of PNPI synchrocyclotron with fixed energy of 1000 MeV is used for the stereotaxic proton therapy of different head brain diseases. 1300 patients have been treated during this time. The advantage of high energy beam (1000 MeV) is low scattering of protons in the irradiated tissue. This factor allows to form the dose field with high edge gradients (20%/mm) that is especially important for the irradiation of the intra-cranium targets placed in immediate proximity to the life critical parts of the brain. Fixation of the 6 0mm diameter proton beam at the isodose centre with accuracy of ±1.0 mm, two-dimensional rotation technique of the irradiation provide a very high ratio of the dose in the irradiation zone to the dose at the object's surface equal to 200:1. The absorbed doses are: 120-150 Gy for normal hypophysis, 100-120 Gy for pituitary adenomas and 40-70 Gy for arterio-venous malformation at the rate of absorbed dose up to 50 Gy/min. In the paper the dynamics and the efficiency of 1000 MeV proton therapy treatment of the brain deceases are given. At present time the feasibility study is in progress with the goal to create a proton therapy on Bragg peak by means of the moderation of 1000 MeV proton beam in the absorber down to 200 MeV, energy required for radiotherapy of deep seated tumors.

  10. 1000 MeV Proton beam therapy facility at Petersburg Nuclear Physics Institute Synchrocyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Abrosimov, N K [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Gavrikov, Yu A [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Ivanov, E M [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Karlin, D L [Central Research Institute of Roentgenology and Radiology, 197758, St.Petersburg (Russian Federation); Khanzadeev, A V [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Yalynych, N N [Central Research Institute of Roentgenology and Radiology, 197758, St. Petersburg (Russian Federation); Riabov, G A [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Seliverstov, D M [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Vinogradov, V M [Central Research Institute of Roentgenology and Radiology, 197758, St.Petersburg (Russian Federation)

    2006-05-15

    Since 1975 proton beam of PNPI synchrocyclotron with fixed energy of 1000 MeV is used for the stereotaxic proton therapy of different head brain diseases. 1300 patients have been treated during this time. The advantage of high energy beam (1000 MeV) is low scattering of protons in the irradiated tissue. This factor allows to form the dose field with high edge gradients (20%/mm) that is especially important for the irradiation of the intra-cranium targets placed in immediate proximity to the life critical parts of the brain. Fixation of the 6 0mm diameter proton beam at the isodose centre with accuracy of {+-}1.0 mm, two-dimensional rotation technique of the irradiation provide a very high ratio of the dose in the irradiation zone to the dose at the object's surface equal to 200:1. The absorbed doses are: 120-150 Gy for normal hypophysis, 100-120 Gy for pituitary adenomas and 40-70 Gy for arterio-venous malformation at the rate of absorbed dose up to 50 Gy/min. In the paper the dynamics and the efficiency of 1000 MeV proton therapy treatment of the brain deceases are given. At present time the feasibility study is in progress with the goal to create a proton therapy on Bragg peak by means of the moderation of 1000 MeV proton beam in the absorber down to 200 MeV, energy required for radiotherapy of deep seated tumors.

  11. Effect of electron beam irradiation on physical, physicochemical, and functional properties of liquid egg yolk during frozen storage

    International Nuclear Information System (INIS)

    Raw yolk of 1-d-old eggs was either subjected to linear electron beam irradiation at approximately 2.5 kGy dosage or not processed. Both irradiated and nonprocessed egg yolk samples were stored at -15 C after irradiation. Testing was conducted on 0, 1, 7, 15, 30, and 60 d of storage. Development of storage modulus (G') was delayed in irradiated samples after 7 d, which suggests that less structure was developed in irradiated egg yolk than in nonprocessed egg yolk during storage. Irradiated samples retained more soluble protein within the first 7 d and showed slightly improved emulsion capacity over that from nonprocessed samples. However, irradiated egg yolk was less bright than nonprocessed samples. No differences were observed in SDS-PAGE patterns of soluble proteins and delipidized low density lipoprotein (LDL). The LDL isolated from irradiated liquid egg yolk showed no difference in N-terminal amino acids compared to that of nonprocessed egg yolk, indicating no detectable cleavage of LDL. However, the denaturation temperature of irradiated samples at Day 0 shifted about 1 C lower than that of the nonprocessed sample. Results indicated that electron beam irradiation did not cause significant physical, chemical or functional changes of egg yolk, or cleavage of egg yolk protein. Therefore, electron beam irradiation could serve as a preservation method for liquid egg yolk

  12. The large-area CdTe thin film for CdS/CdTe solar cell prepared by physical vapor deposition in medium pressure

    Science.gov (United States)

    Luo, Run; Liu, Bo; Yang, Xiaoyan; Bao, Zheng; Li, Bing; Zhang, Jingquan; Li, Wei; Wu, Lili; Feng, Lianghuan

    2016-01-01

    The Cadmium telluride (CdTe) thin film has been prepared by physical vapor deposition (PVD), the Ar + O2 pressure is about 0.9 kPa. This method is a newer technique to deposit CdTe thin film in large area, and the size of the film is 30 × 40 cm2. This method is much different from the close-spaced sublimation (CSS), as the relevance between the source temperature and the substrate temperature is weak, and the gas phase of CdTe is transferred to the substrate by Ar + O2 flow. Through this method, the compact and uniform CdTe film (30 × 40 cm2) has been achieved, and the performances of the CdTe thin film have been determined by transmission spectrum, SEM and XRD. The film is observed to be compact with a good crystallinity, the CdTe is polycrystalline with a cubic structure and a strongly preferred (1 1 1) orientation. Using the CdTe thin film (3 × 5 cm2) which is taken from the deposited large-area film, the 14.6% efficiency CdS/CdTe thin film solar cell has been prepared successfully. The structure of the cell is glass/FTO/CdS/CdTe/graphite slurry/Au, short circuit current density (Jsc) of the cell is 26.9 mA/cm2, open circuit voltage (Voc) is 823 mV, and filling factor (FF) is 66.05%. This technique can be a quite promising method to apply in the industrial production, as it has great prospects in the fabricating of large-area CdTe film.

  13. New Copper wide range nanosensor electrode prepared by physical vapor deposition at oblique angles for the non-enzimatic determination of glucose

    International Nuclear Information System (INIS)

    In this work a novel Cu nanostructured electrode is presented. Cu tilted nanocolumnar and porous thin films have been prepared by physical vapor deposition (PVD) in an oblique angle configuration and characterized by different techniques. Cyclic voltammetry and amperometry were used to study the sensing ability of the copper films deposited on ITO to quantitatively determine glucose and to optimize the experimental conditions of detection. Scanning electron microscopy data revealed that the film microstructure consists of tilted nanocolumns of around 70 nm of diameter and an inclination of 65° with respect to the surface normal that extend through the total thickness of the layer of ca. 300 nm. X ray photoelectron spectroscopy and Raman, used to determine the oxidation state of Cu, revealed that an oxy/hydroxide external layer formed around the nanocolumns is the active phase responsible for the electrocatalytic detection of glucose. Under optimized conditions, the CuO/Cu nanoporous/ITO electrode presented a sensitivity of 1.41 A mol dm−3 cm−2 (R2:0.999) with a limit of detection of 0.36 μmol dm−3 and a reproducibility of 3.42%.The selectivity of the proposed sensor was checked against various interferences, including physiological compounds, different sugars and ethanol, thereby showing excellent anti-interference properties. The CuO/Cu nanoporous/ITO electrode was also used successfully to determine glucose in blood samples showing a performance comparable to that of a commercial glucometer. An extended working range covering from 1 to 5 × 10−3 mol dm−3 was determined for these sensor films which, in this way, could be applied for different analytical purposes including agro industrial liquids

  14. THE EFFECT OF NITROGEN GAS FLOW RATE ON THE PROPERTIES OF TiN-COATED HIGH-SPEED STEEL (HSS) USING CATHODIC ARC EVAPORATION PHYSICAL VAPOR DEPOSITION (PVD) TECHNIQUE

    OpenAIRE

    ALI MUBARAK; ESAH BINTI HAMZAH; MOHD RADZI HJ. MOHD TOFF; ABDUL HAKIM BIN HASHIM

    2005-01-01

    Cathodic arc evaporation (CAE) is a widely-used technique for generating highly ionized plasma from which hard and wear resistant physical vapor deposition (PVD) coatings can be deposited. A major drawback of this technique is the emission of micrometer-sized droplets of cathode material from the arc spot, which are commonly referred to as "macroparticles." In present study, titanium nitride (TiN) coatings on high-speed steel (HSS) coupons were produced with a cathodic arc evaporation techniq...

  15. New development of laser ion source for highly charged ion beam production at Institute of Modern Physics (invited).

    Science.gov (United States)

    Zhao, H Y; Zhang, J J; Jin, Q Y; Liu, W; Wang, G C; Sun, L T; Zhang, X Z; Zhao, H W

    2016-02-01

    A laser ion source based on Nd:YAG laser has been being studied at the Institute of Modern Physics for the production of high intensity high charge state heavy ion beams in the past ten years, for possible applications both in a future accelerator complex and in heavy ion cancer therapy facilities. Based on the previous results for the production of multiple-charged ions from a wide range of heavy elements with a 3 J/8 ns Nd:YAG laser [Zhao et al., Rev. Sci. Instrum. 85, 02B910 (2014)], higher laser energy and intensity in the focal spot are necessary for the production of highly charged ions from the elements heavier than aluminum. Therefore, the laser ion source was upgraded with a new Nd:YAG laser, the maximum energy of which is 8 J and the pulse duration can be adjusted from 8 to 18 ns. Since then, the charge state distributions of ions from various elements generated by the 8 J Nd:YAG laser were investigated for different experimental conditions, such as laser energy, pulse duration, power density in the focal spot, and incidence angle. It was shown that the incidence angle is one of the most important parameters for the production of highly charged ions. The capability of producing highly charged ions from the elements lighter than silver was demonstrated with the incidence angle of 10° and laser power density of 8 × 10(13) W cm(-2) in the focal spot, which makes a laser ion source complementary to the superconducting electron cyclotron resonance ion source for the future accelerator complex especially in terms of the ion beam production from some refractory elements. Nevertheless, great efforts with regard to the extraction of intense ion beams, modification of the ion beam pulse duration, and reliability of the ion source still need to be made for practical applications. PMID:26931978

  16. New development of laser ion source for highly charged ion beam production at Institute of Modern Physics (invited)

    International Nuclear Information System (INIS)

    A laser ion source based on Nd:YAG laser has been being studied at the Institute of Modern Physics for the production of high intensity high charge state heavy ion beams in the past ten years, for possible applications both in a future accelerator complex and in heavy ion cancer therapy facilities. Based on the previous results for the production of multiple-charged ions from a wide range of heavy elements with a 3 J/8 ns Nd:YAG laser [Zhao et al., Rev. Sci. Instrum. 85, 02B910 (2014)], higher laser energy and intensity in the focal spot are necessary for the production of highly charged ions from the elements heavier than aluminum. Therefore, the laser ion source was upgraded with a new Nd:YAG laser, the maximum energy of which is 8 J and the pulse duration can be adjusted from 8 to 18 ns. Since then, the charge state distributions of ions from various elements generated by the 8 J Nd:YAG laser were investigated for different experimental conditions, such as laser energy, pulse duration, power density in the focal spot, and incidence angle. It was shown that the incidence angle is one of the most important parameters for the production of highly charged ions. The capability of producing highly charged ions from the elements lighter than silver was demonstrated with the incidence angle of 10° and laser power density of 8 × 1013 W cm−2 in the focal spot, which makes a laser ion source complementary to the superconducting electron cyclotron resonance ion source for the future accelerator complex especially in terms of the ion beam production from some refractory elements. Nevertheless, great efforts with regard to the extraction of intense ion beams, modification of the ion beam pulse duration, and reliability of the ion source still need to be made for practical applications

  17. New development of laser ion source for highly charged ion beam production at Institute of Modern Physics (invited)

    Science.gov (United States)

    Zhao, H. Y.; Zhang, J. J.; Jin, Q. Y.; Liu, W.; Wang, G. C.; Sun, L. T.; Zhang, X. Z.; Zhao, H. W.

    2016-02-01

    A laser ion source based on Nd:YAG laser has been being studied at the Institute of Modern Physics for the production of high intensity high charge state heavy ion beams in the past ten years, for possible applications both in a future accelerator complex and in heavy ion cancer therapy facilities. Based on the previous results for the production of multiple-charged ions from a wide range of heavy elements with a 3 J/8 ns Nd:YAG laser [Zhao et al., Rev. Sci. Instrum. 85, 02B910 (2014)], higher laser energy and intensity in the focal spot are necessary for the production of highly charged ions from the elements heavier than aluminum. Therefore, the laser ion source was upgraded with a new Nd:YAG laser, the maximum energy of which is 8 J and the pulse duration can be adjusted from 8 to 18 ns. Since then, the charge state distributions of ions from various elements generated by the 8 J Nd:YAG laser were investigated for different experimental conditions, such as laser energy, pulse duration, power density in the focal spot, and incidence angle. It was shown that the incidence angle is one of the most important parameters for the production of highly charged ions. The capability of producing highly charged ions from the elements lighter than silver was demonstrated with the incidence angle of 10° and laser power density of 8 × 1013 W cm-2 in the focal spot, which makes a laser ion source complementary to the superconducting electron cyclotron resonance ion source for the future accelerator complex especially in terms of the ion beam production from some refractory elements. Nevertheless, great efforts with regard to the extraction of intense ion beams, modification of the ion beam pulse duration, and reliability of the ion source still need to be made for practical applications.

  18. New development of laser ion source for highly charged ion beam production at Institute of Modern Physics (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, H. Y., E-mail: zhaohy@impcas.ac.cn; Zhang, J. J.; Jin, Q. Y.; Sun, L. T.; Zhang, X. Z.; Zhao, H. W. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, W.; Wang, G. C. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2016-02-15

    A laser ion source based on Nd:YAG laser has been being studied at the Institute of Modern Physics for the production of high intensity high charge state heavy ion beams in the past ten years, for possible applications both in a future accelerator complex and in heavy ion cancer therapy facilities. Based on the previous results for the production of multiple-charged ions from a wide range of heavy elements with a 3 J/8 ns Nd:YAG laser [Zhao et al., Rev. Sci. Instrum. 85, 02B910 (2014)], higher laser energy and intensity in the focal spot are necessary for the production of highly charged ions from the elements heavier than aluminum. Therefore, the laser ion source was upgraded with a new Nd:YAG laser, the maximum energy of which is 8 J and the pulse duration can be adjusted from 8 to 18 ns. Since then, the charge state distributions of ions from various elements generated by the 8 J Nd:YAG laser were investigated for different experimental conditions, such as laser energy, pulse duration, power density in the focal spot, and incidence angle. It was shown that the incidence angle is one of the most important parameters for the production of highly charged ions. The capability of producing highly charged ions from the elements lighter than silver was demonstrated with the incidence angle of 10° and laser power density of 8 × 10{sup 13} W cm{sup −2} in the focal spot, which makes a laser ion source complementary to the superconducting electron cyclotron resonance ion source for the future accelerator complex especially in terms of the ion beam production from some refractory elements. Nevertheless, great efforts with regard to the extraction of intense ion beams, modification of the ion beam pulse duration, and reliability of the ion source still need to be made for practical applications.

  19. Vapor deposition of tantalum and tantalum compounds

    International Nuclear Information System (INIS)

    Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

  20. Stem Cell Physics. Multiple-Laser-Beam Treatment of Parkinson's Disease

    Science.gov (United States)

    Stefan, V.

    2013-03-01

    A novel method for the treatment of Parkinson's disease is proposed. Pluripotent stem cells are laser cultured, using ultrashort wavelength, (around 0.1 micron-ultraviolet radiation-with intensities of a few mW/cm2) , multiple laser beams.[2] The multiple-energy laser photons[3] interact with the neuron DNA molecules to be cloned. The laser created dopaminergic substantia nigra neurons can be, (theoretically), laser transplanted, (a higher focusing precision as compared to a syringe method), into the striatum or substantia nigra regions of the brain, or both. Supported by Nikola Tesla Labs, Stefan University.

  1. Annual Report 2014 - Institute of Ion Beam Physics and Materials Research

    OpenAIRE

    2015-01-01

    This past year 2014 was the year when we finally completely arrived as a “full member” in the Helmholtz Association. This is related to the successfully passed research evaluation in the framework of the Program Oriented Funding (POF), which will give us a stable and predictable funding for the next five years (2015 – 2019). This is particularly true for our large-scale user facilities, like the Ion Beam Center (IBC) and the electron accelerator ELBE with the free-electron laser. Most of our ...

  2. Two-photon physics with ultrahigh-energy heavy-ion beams

    International Nuclear Information System (INIS)

    Relativistic heavy-ion collisions become interesting as a source of intense beams of photons, where the two-photon production of particles like the Higgs boson can be studied, when the nuclear charges act coherently. To exclude contributions from the strong interaction the nuclei are treated as two non-overlapping black discs in impact parameter space and the results are compared to calculations which account for the nuclear size by the elastic form factor. The cross sections for the production of an intermediate-mass Higgs boson and of pairs of heavy fermions, vector bosons and charge supersymmetric particles are shown for two hadron colliders. (author)

  3. SHOCK IMPACT OF HIGH ENERGY/INTENSITY BEAMS WITH MATTER AND HIGH ENERGY DENSITY PHYSICS

    OpenAIRE

    Blanco Sancho, Juan; Schmidt, Rudiger

    2010-01-01

    The purpose of this study is to assess the damage caused to the equipment (beamdump, collimators etc) in case of an accident involving full impact of the LHC beam. First, the FLUKA code [1] is used to calculate the proton energy loss in solid carbon and this energy loss data is used as input to a two–dimensional hydrodynamic computer code, BIG2 [2] to study the thermodynamic and hydrodynamic response of the target. The BIG2 code is run for 5 μs and the density distribution at the end of this ...

  4. The program in muon and neutrino physics: Superbeams, cold muon beams, neutrino factory and the muon collider

    Energy Technology Data Exchange (ETDEWEB)

    R. Raja et al.

    2001-08-08

    The concept of a Muon Collider was first proposed by Budker [10] and by Skrinsky [11] in the 60s and early 70s. However, there was little substance to the concept until the idea of ionization cooling was developed by Skrinsky and Parkhomchuk [12]. The ionization cooling approach was expanded by Neufer [13] and then by Palmer [14], whose work led to the formation of the Neutrino Factory and Muon Collider Collaboration (MC) [3] in 1995. The concept of a neutrino source based on a pion storage ring was originally considered by Koshkarev [18]. However, the intensity of the muons created within the ring from pion decay was too low to provide a useful neutrino source. The Muon Collider concept provided a way to produce a very intense muon source. The physics potential of neutrino beams produced by muon storage rings was investigated by Geer in 1997 at a Fermilab workshop [19, 20] where it became evident that the neutrino beams produced by muon storage rings needed for the muon collider were exciting on their own merit. The neutrino factory concept quickly captured the imagination of the particle physics community, driven in large part by the exciting atmospheric neutrino deficit results from the SuperKamiokande experiment. As a result, the MC realized that a Neutrino Factory could be an important first step toward a Muon Collider and the physics that could be addressed by a Neutrino Factory was interesting in its own right. With this in mind, the MC has shifted its primary emphasis toward the issues relevant to a Neutrino Factory. There is also considerable international activity on Neutrino Factories, with international conferences held at Lyon in 1999, Monterey in 2000 [21], Tsukuba in 2001 [22], and another planned for London in 2002.

  5. The Interaction of Photon Beams with the DNA Molecules: Genomic Medical Physics

    Science.gov (United States)

    Stefan, V. Alexander

    2009-03-01

    I propose a novel method for the modification of the corrupted human DNAootnotetextJ.D. Watson and F. H. C. Crick, Nature, 171, 737-738 (1953). code that causes particular genetic disease. The method is based on the nonlinear interaction between the DNA molecule and the ``modulation photons'' generated in beat wave driven free electron laser, BW-FEL.ootnotetextV. Alexander Stefan. Beat Wave Driven Free Electron Laser (S-U-Press, 2002, La Jolla, CA)[cf. V. Stefan, et al., Bull. Am. Phys. Soc. 32, No. 9, 1713 (1987)] The BW-FEL frequency is given by ν˜γ^2nφe (γ is the free electron beam relativistic factor, n is the harmonic number of the electron Bernstein plasma mode, and φe is the electron cyclotron frequency). The meV ``carrier photons'' are focused on the area of the brain, the source-center of a genetic disease. For the BW-FEL parameters: the free electron beam guiding d.c. magnetic field ˜ 1kG, γ˜10^3, and n=10, the keV ``modulation photons'' are generated, which are easily focused on the nucleotides. By modulating the frequency of the BW-FEL, the parametric resonance with the different DNA (sub-DNA) eigen molecular oscillation-modes are achieved, leading to the ``knock-on'' of the unwanted (corrupted) nucleotides.

  6. Radiation therapy with laser-driven accelerated particle beams: physical dosimetry and spatial dose distribution

    International Nuclear Information System (INIS)

    One of the main goals of the Munich Centre for Advanced Photonics (MAP) is the application of laser driven accelerated (LDA) particle beams for radiation therapy. Due to the unique acceleration process ultrashort particle pulses of high intensity (> 107 particles /cm2/ns) are generated, which makes online detection an ambitious task. So far, state of the art detection of laser accelerated ion pulses are non-electronic detectors like radiochromic films (RCF), imaging plates (IP) or nuclear track detectors (e.g. CR39). All these kind of detectors are offline detectors requiring several hours of processing time. For this reason they are not qualified for an application in radiation therapy where quantitative real time detection of the beam is an essential prerequisite. Therefore we are investigating pixel detectors for real time monitoring of LDA particle pulses. First tests of commercially available systems with 8-20 MeV protons are presented. For radiobiological experiments second generation Gafchromic films (EBT2) have been calibrated with protons of 12 and 20 MeV for a dose range of 0.3-10 Gy. Dose verification in proton irradiation of subcutaneous tumours in mice was successfully accomplished using these films.

  7. Radiation therapy with laser-driven accelerated particle beams: physical dosimetry and spatial dose distribution

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Sabine; Assmann, Walter [Ludwig-Maximilians Universitaet Muenchen (Germany); Kneschaurek, Peter; Wilkens, Jan [MRI, Technische Universitaet Muenchen (Germany)

    2011-07-01

    One of the main goals of the Munich Centre for Advanced Photonics (MAP) is the application of laser driven accelerated (LDA) particle beams for radiation therapy. Due to the unique acceleration process ultrashort particle pulses of high intensity (> 10{sup 7} particles /cm{sup 2}/ns) are generated, which makes online detection an ambitious task. So far, state of the art detection of laser accelerated ion pulses are non-electronic detectors like radiochromic films (RCF), imaging plates (IP) or nuclear track detectors (e.g. CR39). All these kind of detectors are offline detectors requiring several hours of processing time. For this reason they are not qualified for an application in radiation therapy where quantitative real time detection of the beam is an essential prerequisite. Therefore we are investigating pixel detectors for real time monitoring of LDA particle pulses. First tests of commercially available systems with 8-20 MeV protons are presented. For radiobiological experiments second generation Gafchromic films (EBT2) have been calibrated with protons of 12 and 20 MeV for a dose range of 0.3-10 Gy. Dose verification in proton irradiation of subcutaneous tumours in mice was successfully accomplished using these films.

  8. Vapor extractor

    Energy Technology Data Exchange (ETDEWEB)

    Bronder, G.A.; Bronder, L.R.

    1924-10-21

    A vapor extractor is described comprising a conveyer having compartments open at their top and bottom sides for a material to be conveyed, a plate forming a support for the conveyer and its compartments, means to move the conveyer over the plate with the material in the compartments, the movements of the conveyer forming ridges in the material that project above the walls of the compartments and means to remove the peaks of the ridges and thereby distribute the material composing the ridges into the bottom portion of the conveyer.

  9. 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.

  10. IBR-2 reactor power start-up and first physical experiments on its beams

    International Nuclear Information System (INIS)

    The design is described of the IBR-2 pulse fast reactor designated for investigations into nuclear physics, condensed medium physics, molecular biology, elementary particle physics (fundamental properties of the neutron) as well as for solving various applied problems. The IBR-2 core is loaded with plutonium dioxide fuel of about 90 kg total mass. The fuel elements are sodium, cooled with a 300 deg C inlet temperature. The cooling system is two-circuit, two-loop with the 100 m3/h sodium flow rate. The reactor is surrounded by water neutron moderators which are ''scanned'' by 14 horizontal channels. The power pulse is formed by the reactivity modulator in the form of two coaxially positioned mobile neutron reflectors - the basic one (BR) and additional one (AR). The BR rotation frequency equals 1500 min-1. The pulse frequency is varied discretely by the AR, being at rest or rotating at a lower rate. In 1982 the IBR-2 attained the average power 2 MW at a BR rotation frequency equal to 1500 mm-1 and a pulse frequency equal to 25 Hz, which corresponds to pulse reactor power of 270 MW. The reactor main frequency mode 5 Hz at 2 MW power was realized in 1984, the reactor peak power achieved 1350 MW. Results of first physical studies conducted during the reactor power start-up are presented

  11. The physical and chemical properties of polymerization reaction for contact lens irradiated by electron beam

    International Nuclear Information System (INIS)

    Can EB irradiation be possible the polymerization of HEMA without the cross-linker and initiator? The physical and chemical properties of the polymers are compared between the two polymerization methods Discuss the effects of the EB irradiation on the polymerization for having a good physical properties for the both hard and soft contact lens. EB irradiation can be used to the polymerization reaction and the EB polymerization take place at a very short period of time without any cross-linker and initiator and initiator above 100 kGy of EB dose. The polymer synthesized by EB irradiation can improve the physical properties of contact lens → increase of the OH group on the surface by EB irradiation, resulting in increase o the water content and oxygen permeability of the contact lens The contact lens synthesized by EB irradiation could improve the physical properties of the contact lens, and specially can apply to a disposable soft contact lens with high water content and oxygen permeability

  12. The physical and chemical properties of polymerization reaction for contact lens irradiated by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Sin, Junghyeok; Jun, Jin [Dongshin Univ., Naju (Korea, Republic of)

    2010-07-01

    Can EB irradiation be possible the polymerization of HEMA without the cross-linker and initiator? The physical and chemical properties of the polymers are compared between the two polymerization methods Discuss the effects of the EB irradiation on the polymerization for having a good physical properties for the both hard and soft contact lens. EB irradiation can be used to the polymerization reaction and the EB polymerization take place at a very short period of time without any cross-linker and initiator and initiator above 100 kGy of EB dose. The polymer synthesized by EB irradiation can improve the physical properties of contact lens {yields} increase of the OH group on the surface by EB irradiation, resulting in increase o the water content and oxygen permeability of the contact lens The contact lens synthesized by EB irradiation could improve the physical properties of the contact lens, and specially can apply to a disposable soft contact lens with high water content and oxygen permeability.

  13. Physical properties of ITO thin films prepared by ion-assisted electron beam evaporation

    Science.gov (United States)

    Qiu, Yang; Jin, Yangli; Zhao, Hua; Xu, Bo; Wang, Jiajia

    2014-12-01

    Tin doped indium oxide (ITO) thin films were prepared on IR glass substrates at different oxygen flow rate by ion-assisted electron beam evaporation method. Properties such as microstructure, morphology, sheet resistance and optical transmittance were investigated by X-ray diffractometer, SEM, four-point probe and UV-VIS-IR spectrophotometer, respectively. Lattice constant, inner stress level and energy band gap (Eg) of ITO thin films as-deposited were calculated and discussed. The mechanical properties of ITO thin films were studied by scratching method. The measurements were performed by scratch tester and the results were recorded as acoustic emission spectra and scratch track images taken by SEM. Relationship between inner stress level and mechanical performance was investigated in detail.

  14. R&D ERL: Beam dynamics, parameters, and physics to be learned

    Energy Technology Data Exchange (ETDEWEB)

    Kayran, D.

    2010-02-01

    The R&D ERL facility at BNL aims to demonstrate CW operation of ERL with average beam current in the range of 0.1-1 ampere, combined with very high efficiency of energy recovery. The ERL is being installed in one of the spacious bays in Bldg. 912 of the RHIC/AGS complex (Fig. 1). The bay is equipped with an overhead crane. The facility has a control room, two service rooms and a shielded ERL cave. The control room is located outside of the bay in a separate building. The single story house is used for a high voltage power supply for 1 MW klystron. The two-story unit houses a laser room, the CW 1 MW klystron with its accessories, most of the power supplies and electronics. The ERL R&D program has been started by the Collider Accelerator Department (C-AD) at BNL as an important stepping-stone for 10-fold increase of the luminosity of the Relativistic Heavy Ion Collider (RHIC) using relativistic electron cooling of gold ion beams with energy of 100 GeV per nucleon. Furthermore, the ERL R&D program extends toward a possibility of using 10-20 GeV ERL for future electron-hadron/heavy ion collider, MeRHIC/eRHIC. These projects are the driving force behind the development of ampere-class ERL technology, which will find many applications including light sources and FELs. The intensive R&D program geared towards the construction of the prototype ERL is under way: from development of high efficiency photo-cathodes to the development of new merging system compatible with emittance compensation.

  15. A simple and fast physics-based analytical method to calculate therapeutic and stray doses from external beam, megavoltage x-ray therapy

    OpenAIRE

    Wilson, Lydia J; Newhauser, Wayne D.

    2015-01-01

    State-of-the-art radiotherapy treatment planning systems provide reliable estimates of the therapeutic radiation but are known to underestimate or neglect the stray radiation exposures. Most commonly, stray radiation exposures are reconstructed using empirical formulas or lookup tables. The purpose of this study was to develop the basic physics of a model capable of calculating the total absorbed dose both inside and outside of the therapeutic radiation beam for external beam photon therapy. ...

  16. Material content of binary physical mixtures as measured with a dual-energy beam of γ rays

    International Nuclear Information System (INIS)

    The content of water and soil in physical intermixtures was measured simultaneously and nondestructively by the attenuation of a dual-energy beam of γ rays. The beam, 1 mm by about 3 cm in cross section, was devised by placing a 280-mCi source of 137Cs behind a 389-mCi source of 241Am, with lead collimators suitably aligned in front of each source and the scintillation probe. The probe was connected in parallel to two separate amplifier-analyzer-scaler systems, one being set in the integral mode to receive all pulses greater than 550 keV (for 137Cs, 662-keV peak), with the other being set in the differential mode to receive all pulses in a band 35 to 85 keV (for 241Am, 60-keV peak). When related to the count intensity in the high-energy range, the count intensity e caused by 137Cs in the low-energy band was empirically found to be independent of the material in the binary mixture (soil and/or water) placed in the beam for measurement. Also, e could be well expressed by a cubic polynomial that was then used along with a dead-time correction to determine the attenuated count intensity attributable to the 241Am source alone. Calibration of the system was then possible. Over-all measuring accuracy was on the order of plus-minus 0.01 cm3/cm3 in water content and plus-minus 0.02 g/cm3 in soil content (bulk density) for a counting period of 5 min; these changed to plus-minus 0.04 cm3/cm3 or g/cm3 for a counting period of 5 sec. (U.S.)

  17. Successfully Managing the Experimental Area of a Large Physics Experiment from Civil Engineering to the First Beams

    CERN Document Server

    Butin, F

    2010-01-01

    The role of "Experimental Area Manager" supported by a well organized, charismatic and motivated team is absolutely essential for managing the huge effort needed for a multi-cultural, multi-disciplinary installation of cathedral-size underground caverns housing a billion dollar physics experiment. Between the years 2002 and 2008, we supervised and coordinated the ATLAS work site at LHC, from the end of the civil engineering to the first circulating beams, culminating with 240 workers on the site, 24 hours a day, 7 days a week, with activities taking place simultaneously on the surface, in the 60 m shafts and in the 100 m underground experimental cavern. We depict the activities preparation scheme (including tasks ranging from the installation of 280 ton cranes to super-delicate silicon detectors), the work-site organization method, the safety management that was a top priority throughout the whole project, and the opencommunication strategy that required maintaining permanent public visits. The accumulation o...

  18. Beam test studies of 3D pixel sensors irradiated non-uniformly for the ATLAS forward physics detector

    International Nuclear Information System (INIS)

    Pixel detectors with cylindrical electrodes that penetrate the silicon substrate (so called 3D detectors) offer advantages over standard planar sensors in terms of radiation hardness, since the electrode distance is decoupled from the bulk thickness. In recent years significant progress has been made in the development of 3D sensors, which culminated in the sensor production for the ATLAS Insertable B-Layer (IBL) upgrade carried out at CNM (Barcelona, Spain) and FBK (Trento, Italy). Based on this success, the ATLAS Forward Physics (AFP) experiment has selected the 3D pixel sensor technology for the tracking detector. The AFP project presents a new challenge due to the need for a reduced dead area with respect to IBL, and the in-homogeneous nature of the radiation dose distribution in the sensor. Electrical characterization of the first AFP prototypes and beam test studies of 3D pixel devices irradiated non-uniformly are presented in this paper

  19. A survey of the Italian research in solid state physics by infrared spectroscopy with electron-beam sources

    International Nuclear Information System (INIS)

    Two beamlines for the use of InfraRed Synchrotron Radiation (IRSR) are presently working in Italy, at the ELETTRA storage ring in Trieste, and at the collider DAFNE in Frascati. A third facility, SPARC in Frascati, has been equipped for the extraction of Terahertz radiation with the aim to perform pump-probe time-domain experiments. Here we describe those apparata and we review the main results that the Italian groups have obtained therein, in recent years, in solid-state physics. We also describe the experiments performed in collaboration with the storage ring BESSY in Berlin, for the exploitation of Coherent Synchrotron Radiation, and the terahertz beam line recently implemented at SPARC, the Free Electron Laser of Laboratori Nazionali di Frascati

  20. Beam test studies of 3D pixel sensors irradiated non-uniformly for the ATLAS forward physics detector

    Energy Technology Data Exchange (ETDEWEB)

    Grinstein, S., E-mail: sgrinstein@ifae.es [ICREA and Institut de Física d' Altes Energies (IFAE), Barcelona (Spain); Baselga, M. [Centro Nacional de Microelectronica, CNM-IMB (CSIC), Barcelona (Spain); Boscardin, M. [Fondazione Bruno Kessler, FBK-CMM, Trento (Italy); Christophersen, M. [U.S. Naval Research Laboratory, Washington (United States); Da Via, C. [School of Physics and Astronomy, University of Manchester, Manchester (United Kingdom); Dalla Betta, G.-F. [Universita degli Studi di Trento and INFN, Trento (Italy); Darbo, G. [INFN Sezione di Genova, Genova (Italy); Fadeyev, V. [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz (United States); Fleta, C. [Centro Nacional de Microelectronica, CNM-IMB (CSIC), Barcelona (Spain); Gemme, C. [Universita degli Studi di Trento and INFN, Trento (Italy); Grenier, P. [SLAC National Accelerator Laboratory, Menlo Park (United States); Jimenez, A.; Lopez, I.; Micelli, A. [ICREA and Institut de Física d' Altes Energies (IFAE), Barcelona (Spain); Nelist, C. [INFN Sezione di Genova, Genova (Italy); Parker, S. [University of Hawaii, c/o Lawrence Berkeley Laboratory, Berkeley (United States); Pellegrini, G. [Centro Nacional de Microelectronica, CNM-IMB (CSIC), Barcelona (Spain); Phlips, B. [U.S. Naval Research Laboratory, Washington (United States); Pohl, D.-L. [University of Bonn, Bonn (Germany); Sadrozinski, H.F.-W. [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz (United States); and others

    2013-12-01

    Pixel detectors with cylindrical electrodes that penetrate the silicon substrate (so called 3D detectors) offer advantages over standard planar sensors in terms of radiation hardness, since the electrode distance is decoupled from the bulk thickness. In recent years significant progress has been made in the development of 3D sensors, which culminated in the sensor production for the ATLAS Insertable B-Layer (IBL) upgrade carried out at CNM (Barcelona, Spain) and FBK (Trento, Italy). Based on this success, the ATLAS Forward Physics (AFP) experiment has selected the 3D pixel sensor technology for the tracking detector. The AFP project presents a new challenge due to the need for a reduced dead area with respect to IBL, and the in-homogeneous nature of the radiation dose distribution in the sensor. Electrical characterization of the first AFP prototypes and beam test studies of 3D pixel devices irradiated non-uniformly are presented in this paper.

  1. Beam Test Studies of 3D Pixel Sensors Irradiated Non-Uniformly for the ATLAS Forward Physics Detector

    CERN Document Server

    Grinstein, S; Boscardin, M; Christophersen, M; Da Via, C; Betta, G -F Dalla; Darbo, G; Fadeyev, V; Fleta, C; Gemme, C; Grenier, P; Jimenez, A; Lopez, I; Micelli, A; Nelist, C; Parker, S; Pellegrini, G; Phlips, B; Pohl, D L; Sadrozinski, H F -W; Sicho, P; Tsiskaridze, S

    2013-01-01

    Pixel detectors with cylindrical electrodes that penetrate the silicon substrate (so called 3D detectors) offer advantages over standard planar sensors in terms of radiation hardness, since the electrode distance is decoupled from the bulk thickness. In recent years significant progress has been made in the development of 3D sensors, which culminated in the sensor production for the ATLAS Insertable B-Layer (IBL) upgrade carried out at CNM (Barcelona, Spain) and FBK (Trento, Italy). Based on this success, the ATLAS Forward Physics (AFP) experiment has selected the 3D pixel sensor technology for the tracking detector. The AFP project presents a new challenge due to the need for a reduced dead area with respect to IBL, and the in-homogeneous nature of the radiation dose distribution in the sensor. Electrical characterization of the first AFP prototypes and beam test studies of 3D pixel devices irradiated non-uniformly are presented in this paper.

  2. Physics of two-nucleon system by polarized beam and polarized targets

    International Nuclear Information System (INIS)

    Recent progress on the studies of dibaryons is reviewed. The pp resonances 1D2 and 3F3 have been almost established by the recent measurement of the difference of longitudinal polarization total cross sections at SIN and LAMPF and the difference of transverse polarization total cross sections at TRIUMF. The Argand diagram obtained by several groups also supported the presence of these resonances. Apart from these, 3P2 and 3F4 resonances were suggested by the Argand diagrams, and 3D2 and 1P1 were predicted at low energy theoretically. It is favorable to regard the dibaryons as the new state of hadrons. This was supported by the indication of the existence of the 1F3 resonance with the minus parity at M = 2.21 GeV, which was suggested by the partial wave analysis of np world data. This resonance was supported by the measurement of the difference of longitudinal polarization total cross sections (I=O) at ANL and np reaction cross section (I=O) by the Freiburg group. The measurement of the differential cross section of np scattering in the forward direction was recommended as a proposal at KEK. The perfect experiment of n-p scattering using polarized beam available in future is recommended. (Ito, K.)

  3. The Physics and Applications of High Brightness Beams: Working Group C Summary on Applications to FELS

    International Nuclear Information System (INIS)

    This is the summary of the activities in working group C, ''Application to FELs,'' which was based in the Bithia room at the Joint ICFA Advanced Accelerator and Beam Dynamics Workshop on July 1-6, 2002 in Chia Laguna, Sardinia, Italy. Working group C was small in relation to the other working groups at that workshop. Attendees include Enrica Chiadroni, University of Rome ape with an identical pulse length. ''La Sapienza'', Luca Giannessi, ENEA, Steve Lidia, LBNL, Vladimir Litvinenko, Duke University, Patrick Muggli, UCLA, Alex Murokh, UCLA, Heinz-Dieter Nuhn, SLAC, Sven Reiche, UCLA, Jamie Rosenzweig, UCLA, Claudio Pellegrini, UCLA, Susan Smith, Daresbury Laboratory, Matthew Thompson, UCLA, Alexander Varfolomeev, Russian Research Center, plus a small number of occasional visitors. The working group addressed a total of nine topics. Each topic was introduced by a presentation, which initiated a discussion of the topic during and after the presentation. The speaker of the introductory presentation facilitated the discussion. There were six topics that were treated in stand-alone sessions of working group C. In addition, there were two joint sessions, one with working group B, which included one topic, and one with working group C, which included two topics. The presentations that were given in the joint sessions are summarized in the working group summary reports for groups B and D, respectively. This summary will only discuss the topics that were addressed in the stand-alone sessions, including Start-To-End Simulations, SASE Experiment, PERSEO, ''Optics Free'' FEL Oscillators, and VISA II

  4. Multiscale Approach to the Physics of Ion-Beam Therapy:. Thermo-Mechanical Damage

    Science.gov (United States)

    Solov'yov, A. V.; Yakubovich, A. V.; Surdutovich, E.

    2012-01-01

    We present a brief overview of the multiscale approach towards the understanding of processes responsible for the radiation damage caused by energetic ions. This knowledge is important because it can be utilized in the ion-beam cancer therapy, which is one of the most advanced modern techniques to cure certain types of cancer. The central element of the multiscale approach is the theoretical evaluation and quantification of DNA damage within cell environment. We consider different pathways of DNA damage and focus on the the illustration of the thermo-mechanical effects caused by the propagation of ions through the biological environment and in particular on the possibility of the creation of the shock waves in the vicinity of the ion tracks. We demonstrate that at the initial stages after ion's passage the shock wave is so strong that it can contribute to the DNA damage due to large pressure gradients developed at the distances of a few nanometers from the ionic tracks. This novel mechanism of the DNA damage provides an important contribution to the cumulative bio-damage caused by low-energy secondary electrons, holes and free radicals.

  5. Physical model for photon beams used on the general electric target radiotherapy treatment planning system

    International Nuclear Information System (INIS)

    The tabulated measured data model for external photon beam planning used on the GE Target system is very powerful, allowing fast and accurate calculations and is extended to incorporate complex planning techniques. This approach is ideally suited for the incorporation of correction factors, defined at any point as the ratio of the dose in an inhomogeneous phantom to the dose in a homogeneous phantom. The correction factor can be determined using techniques such as a generalized Batho power law or the equivalent tissue air ratio method, and the dose in an homogeneous phantom is taken from the measured data tables. The use of tabulated data gives the benefits of very fast calculation times and, when required, the accuracy of sophisticated scatter corrections. The basic model and methods of correcting for inhomogeneities are described. The extension of the two-dimensional model to a three-dimensional model for non-coplanar treatment planning retains the basic principles of the 2D model. (orig./HP)

  6. Physical and mechanical characterization of hydrogels methyl-cellulose synthesized by electron beam irradiation

    International Nuclear Information System (INIS)

    Methylcellulose hydrogels from 5 kinds of molecular weight were synthesized by using electron beam irradiation with the dose range of 10 kGy up to 100 kGy. Hydrogels films with the size of 16cm x 1.2mm were characterized on the degree of swelling, gels content, tensile strength and elongation at break. Measurement by using ubbelohde viscometer, showed that the methyl cellulose's molecular weight (Mv) in the following rank of; SM-4

  7. Optimisation of numerical methods for plasma physics. Application to charged particle beams

    International Nuclear Information System (INIS)

    This thesis presents different numerical methods in order to simulate plasmas or charged particles beams with reduced cost. Movement of charged particles in an electromagnetic field is given by the Vlasov equation. This equation is coupled to the Maxwell equations for the electromagnetic field, or to the Poisson equation in a more simple case. Several models exist for solving this system. In kinetic models, particles are represented by a distribution function f(x,v,t) verifying the Vlasov equation. In the general 3-dimensional case, 7 variables appear in the system and computations become heavy. Fluid models consider macroscopic quantities linked to f, such as density, mean velocity and temperature. These quantities only depend on position x and time t. The cost, but also the precision, are reduced. In the first part of this thesis, a multi-fluid method is used for solving the 1-dimensional Vlasov-Poisson system. It is based on the 'a priori' knowledge of the shape of f. Two possibilities are studied: a sum of Dirac masses and the multi-water-bag model. This kind of methods is rather adapted to systems staying close to the equilibrium. The second part presents the decomposition of f between an equilibrium part and a perturbation. The equilibrium part is solved by a fluid method whereas we use a kinetic method for the perturbation. We construct an asymptotic preserving scheme for the Vlasov-Poisson-BGK system using such a decomposition. The third part deals with the Particle-In-Cell (PIC) method in 2D axisymmetric geometry. A work based on iso-geometric analysis is presented, and then a PIC - Discontinuous Galerkin program computed on graphic card (GPU). This architecture reduces significantly calculation time. (author)

  8. EBIT (Electron Beam Ion Trap), N-Division Experimental Physics. Annual report, 1994

    International Nuclear Information System (INIS)

    The experimental groups in the Electron Beam Ion Trap (EBIT) program continue to perform front-line research with trapped and extracted highly charged ions (HCI) in the areas of ion/surface interactions, atomic spectroscopy, electron-ion interaction and structure measurements, highly charged ion confinement, and EBIT development studies. The ion surface/interaction studies which were initiated five years ago have reached a stage where they an carry out routine investigations, as well as produce breakthrough results towards the development of novel nanotechnology. At EBIT and SuperEBIT studies of the x-ray emission from trapped ions continue to produce significant atomic structure data with high precision for few electron systems of high-Z ions. Furthermore, diagnostics development for magnetic and laser fusion, supporting research for the x-ray laser and weapons programs, and laboratory astrophysics experiments in support of NASA's astrophysics program are a continuing effort. The two-electron contributions to the binding energy of helium like ions were measured for the first time. The results are significant because their precision is an order of magnitude better than those of competing measurements at accelerators, and the novel technique isolates the energy corrections that are the most interesting. The RETRAP project which was initiated three years ago has reached a stage where trapping, confining and electronic cooling of HCI ions up to Th80+ can be performed routinely. Measurements of the rates and cross sections for electron transfer from H2 performed to determine the lifetime of HCI up to Xeq+ and Thq+ (35 ≤ q ≤ 80) have been studied at mean energies estimated to be ∼ 5 q eV. This combination of heavy ions with very high charges and very low energies is rare in nature, but may be encountered in planned fusion energy demonstration devices, in highly charged ion sources, or in certain astrophysical events

  9. EBIT (Electron Beam Ion Trap), N-Division Experimental Physics. Annual report, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, D. [ed.

    1995-10-01

    The experimental groups in the Electron Beam Ion Trap (EBIT) program continue to perform front-line research with trapped and extracted highly charged ions (HCI) in the areas of ion/surface interactions, atomic spectroscopy, electron-ion interaction and structure measurements, highly charged ion confinement, and EBIT development studies. The ion surface/interaction studies which were initiated five years ago have reached a stage where they an carry out routine investigations, as well as produce breakthrough results towards the development of novel nanotechnology. At EBIT and SuperEBIT studies of the x-ray emission from trapped ions continue to produce significant atomic structure data with high precision for few electron systems of high-Z ions. Furthermore, diagnostics development for magnetic and laser fusion, supporting research for the x-ray laser and weapons programs, and laboratory astrophysics experiments in support of NASA`s astrophysics program are a continuing effort. The two-electron contributions to the binding energy of helium like ions were measured for the first time. The results are significant because their precision is an order of magnitude better than those of competing measurements at accelerators, and the novel technique isolates the energy corrections that are the most interesting. The RETRAP project which was initiated three years ago has reached a stage where trapping, confining and electronic cooling of HCI ions up to Th{sup 80+} can be performed routinely. Measurements of the rates and cross sections for electron transfer from H{sub 2} performed to determine the lifetime of HCI up to Xe{sup q+} and Th{sup q+} (35 {le} q {le} 80) have been studied at mean energies estimated to be {approximately} 5 q eV. This combination of heavy ions with very high charges and very low energies is rare in nature, but may be encountered in planned fusion energy demonstration devices, in highly charged ion sources, or in certain astrophysical events.

  10. First year of Mark-J: physics with high energy electron-positron colliding beams. Report No. 107

    International Nuclear Information System (INIS)

    This report reviews the experimental investigation of high energy e+e- interactions by the MARK J collaboration at PETRA, the electron-positron colliding beam accelerator at DESY in Hamburg, West Germany. The physics objectives include studies of several purely electromagnetic processes and hadronic final states, which further our knowledge of the nature of the fundamental constituents and of their strong, electromagnetic and weak interactions. Before discussing the physics results, the main features and the principal components of the MARK J detector are discussed in terms of design, function, and performance. Several aspects of the online data collection and the offline analysis are also outlined. Results are presented on tests of quantum electrodynamics using e+e- → e+e-, μ+μ- and tau+tau-, on the measurement of R, the ratio of the hadronic to the point-like muon pair cross section, on the search for new quark flavors, on the discovery of three jet events arising from the radiation of hard noncollinear gluons as predicted by quantum chromodynamics, and on the determination of the strong coupling constant α/sub s/

  11. First year of Mark-J: physics with high energy electron-positron colliding beams. Report No. 107

    Energy Technology Data Exchange (ETDEWEB)

    Aachen DESY M.I.T. NIKHEF Peking Collaboration

    1980-04-01

    This report reviews the experimental investigation of high energy e/sup +/e/sup -/ interactions by the MARK J collaboration at PETRA, the electron-positron colliding beam accelerator at DESY in Hamburg, West Germany. The physics objectives include studies of several purely electromagnetic processes and hadronic final states, which further our knowledge of the nature of the fundamental constituents and of their strong, electromagnetic and weak interactions. Before discussing the physics results, the main features and the principal components of the MARK J detector are discussed in terms of design, function, and performance. Several aspects of the online data collection and the offline analysis are also outlined. Results are presented on tests of quantum electrodynamics using e/sup +/e/sup -/ ..-->.. e/sup +/e/sup -/, ..mu../sup +/..mu../sup -/ and tau/sup +/tau/sup -/, on the measurement of R, the ratio of the hadronic to the point-like muon pair cross section, on the search for new quark flavors, on the discovery of three jet events arising from the radiation of hard noncollinear gluons as predicted by quantum chromodynamics, and on the determination of the strong coupling constant ..cap alpha../sub s/.

  12. Beams of Particles and Papers. The Role of Preprint Archives in High Energy Physics

    CERN Document Server

    Delfanti, Alessandro

    2016-01-01

    In high energy physics scholarly papers circulate primarily through online preprint archives based on a centralized repository, arXiv.org, that physicists simply refer to as 'the archive.' This is not a tool for preservation and memory, but rather a space of flows where written objects are detected and then disappear, and their authors made available for scrutiny. In this work I analyse the reading and publishing practices of two subsets of particle physicists, theorists and experimentalists. In order to be recognized as legitimate and productive members of their community, physicists need to abide by the temporalities and authorial practices structured by the archive. Theorists live in a state of accelerated time that shapes their reading and publishing practices around a 24 hour cycle. Experimentalists resolve to tactics that allow them to circumvent the slowed-down time and invisibility they experience as members of large collaborations. As digital archives for the exchange of preprint articles emerge in o...

  13. The H line: a brand new beam line for fundamental physics at the J-PARC muon facility

    International Nuclear Information System (INIS)

    The muon facility, J-PARC (Muon Science Establishment; MUSE), has been operated since first beam in 2008. Starting with a 200 kW proton beam, the beam intensity has reached 3×106/ muons/s, the most intense pulsed muon beam in the world. A 2 cm thick graphite target permits the extraction of four secondary muon beams. A brand new beam line, the H line, is planned to be constructed. The new beam line is designed to have a large acceptance, will provide the ability to tune the momentum, and use a kicker magnet and/or Wien filter. This beam line will provide an intense beam for experiments that require high statistics and must occupy the experimental areas for a relatively long period.

  14. Electrical characteristics of mixed Zr-Si oxide thin films prepared by ion beam induced chemical vapor deposition at room temperature

    International Nuclear Information System (INIS)

    Mixed Zr-Si oxide thin films have been prepared at room temperature by ion beam decomposition of organometallic volatile precursors. The films were flat and amorphous. They did not present phase segregation of the pure single oxides. A significant amount of impurities (-C-, -CHx, -OH, and other radicals coming from partially decomposed precursors) remained incorporated in the films after the deposition process. This effect is minimized if the Ar content in the O2/Ar bombarding gas is maximized. Static permittivity and breakdown electrical field of the films were determined by capacitance-voltage and current-voltage electrical measurements. It is found that the static permittivity increases non-linearly from ∼ 4 for pure SiO2 to ∼ 15 for pure ZrO2. Most of the dielectric failures in the films were due to extrinsic breakdown failures. The maximum breakdown electrical field decreases from ∼ 10.5 MV/cm for pure SiO2 to ∼ 45 MV/cm for pure ZrO2. These characteristics are justified by high impurity content of the thin films. In addition, the analysis of the conduction mechanisms in the formed dielectrics is consistent to Schottky and Poole-Frenkel emission for low and high electric fields applied, respectively.

  15. Physical principles of ion-beam processing of polymeric materials and applications

    International Nuclear Information System (INIS)

    Irradiation of polymeric materials with energetic ions in the range of several hundreds of keV to several MeV causes drastic changes in physical, chemical, and mechanical properties. Studies indicate that irradiation produces many active radicals which then react with each other, transforming spaghetti-like tangled polymer chains into a highly cross-linked network structure. Analysis of experimental data shows that the most important parameter for cross-linking is the deposited energy density along the ion track, often expressed in terms of linear energy transfer (LET) in units of eV/nm. High LET produces a high number of free radicals over many neighboring molecular chains and thereby facilitates cross-linking. On the other hand, under low LET conditions, radicals are produced so sparsely that cross-linking efficiency decreases. Moreover, the deposited energy in the chain often leads to chain scission when there are no radicals in the neighboring chains for crosslinking. This paper reviews the current understanding of cross-linking mechanisms in terms of nuclear and electronic stopping and their impact on materials' properties

  16. Condensation of water vapor and carbon dioxide in the jet exhausts of rocket engines: 1. Model calculation of the physical conditions in a jet exhaust

    Science.gov (United States)

    Platov, Yu. V.; Alpatov, V. V.; Klyushnikov, V. Yu.

    2014-01-01

    Model calculations have been performed for the temperature and pressure of combustion products in the jet exhaust of rocket engines of last stages of Proton, Molniya, and Start launchers operating in the upper atmosphere at altitudes above 120 km. It has been shown that the condensation of water vapor and carbon dioxide can begin at distances of 100-150 and 450-650 m away from the engine nozzle, respectively.

  17. Vapor pressure of germanium precursors

    Czech Academy of Sciences Publication Activity Database

    Pangrác, Jiří; Fulem, Michal; Hulicius, Eduard; Melichar, Karel; Šimeček, Tomislav; Růžička, K.; Morávek, Pavel; Růžička, V.; Rushworth, S. A.

    2008-01-01

    Roč. 310, č. 23 (2008), s. 4720-4723. ISSN 0022-0248 R&D Projects: GA ČR GA203/08/0217 Institutional research plan: CEZ:AV0Z10100521 Keywords : characterization * phase equilibria * metalorganic vapor phase epitaxy * germanium compounds Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.757, year: 2008

  18. Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics

    Science.gov (United States)

    Yorita, T.; Hatanaka, K.; Fukuda, M.; Ueda, H.; Yasuda, Y.; Morinobu, S.; Tamii, A.; Kamakura, K.

    2014-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP.

  19. Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics

    International Nuclear Information System (INIS)

    An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP

  20. Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics.

    Science.gov (United States)

    Yorita, T; Hatanaka, K; Fukuda, M; Ueda, H; Yasuda, Y; Morinobu, S; Tamii, A; Kamakura, K

    2014-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP. PMID:24593475

  1. Systematic analysis of biological and physical limitations of proton beam range verification with offline PET/CT scans

    Science.gov (United States)

    Knopf, A.; Parodi, K.; Bortfeld, T.; Shih, H. A.; Paganetti, H.

    2009-07-01

    The clinical use of offline positron emission tomography/computed tomography (PET/CT) scans for proton range verification is currently under investigation at the Massachusetts General Hospital (MGH). Validation is achieved by comparing measured activity distributions, acquired in patients after receiving one fraction of proton irradiation, with corresponding Monte Carlo (MC) simulated distributions. Deviations between measured and simulated activity distributions can either reflect errors during the treatment chain from planning to delivery or they can be caused by various inherent challenges of the offline PET/CT verification method. We performed a systematic analysis to assess the impact of the following aspects on the feasibility and accuracy of the offline PET/CT method: (1) biological washout processes, (2) patient motion, (3) Hounsfield unit (HU) based tissue classification for the simulation of the activity distributions and (4) tumor site specific aspects. It was found that the spatial reproducibility of the measured activity distributions is within 1 mm. However, the feasibility of range verification is restricted to a limited amount of positions and tumor sites. Washout effects introduce discrepancies between the measured and simulated ranges of about 4 mm at positions where the proton beam stops in soft tissue. Motion causes spatial deviations of up to 3 cm between measured and simulated activity distributions in abdominopelvic tumor cases. In these later cases, the MC simulated activity distributions were found to be limited to about 35% accuracy in absolute values and about 2 mm in spatial accuracy depending on the correlativity of HU into the physical and biological parameters of the irradiated tissue. Besides, for further specific tumor locations, the beam arrangement, the limited accuracy of rigid co-registration and organ movements can prevent the success of PET/CT range verification. All the addressed factors explain why the proton beam range can

  2. Systematic analysis of biological and physical limitations of proton beam range verification with offline PET/CT scans

    International Nuclear Information System (INIS)

    The clinical use of offline positron emission tomography/computed tomography (PET/CT) scans for proton range verification is currently under investigation at the Massachusetts General Hospital (MGH). Validation is achieved by comparing measured activity distributions, acquired in patients after receiving one fraction of proton irradiation, with corresponding Monte Carlo (MC) simulated distributions. Deviations between measured and simulated activity distributions can either reflect errors during the treatment chain from planning to delivery or they can be caused by various inherent challenges of the offline PET/CT verification method. We performed a systematic analysis to assess the impact of the following aspects on the feasibility and accuracy of the offline PET/CT method: (1) biological washout processes, (2) patient motion, (3) Hounsfield unit (HU) based tissue classification for the simulation of the activity distributions and (4) tumor site specific aspects. It was found that the spatial reproducibility of the measured activity distributions is within 1 mm. However, the feasibility of range verification is restricted to a limited amount of positions and tumor sites. Washout effects introduce discrepancies between the measured and simulated ranges of about 4 mm at positions where the proton beam stops in soft tissue. Motion causes spatial deviations of up to 3 cm between measured and simulated activity distributions in abdominopelvic tumor cases. In these later cases, the MC simulated activity distributions were found to be limited to about 35% accuracy in absolute values and about 2 mm in spatial accuracy depending on the correlativity of HU into the physical and biological parameters of the irradiated tissue. Besides, for further specific tumor locations, the beam arrangement, the limited accuracy of rigid co-registration and organ movements can prevent the success of PET/CT range verification. All the addressed factors explain why the proton beam range can

  3. Master slave topology based, remotely operated, precision X-ray beam profiler and placement system for high pressure physics experiment at Indus-2 beam line

    International Nuclear Information System (INIS)

    RRCAT has commissioned a beam-line on Indus-2 synchrotron facility for carrying out Angle Dispersive X-ray Diffraction measurement. A typical high pressure measurement is carried out by placing the sample in the Diamond Anvil Cell (DAC) with the sample located in a region of beam diameter within 50-100μm. The X-Ray beam has to pass through the DAC to ensure maximum illumination of the sample with the X-Rays. An X-Y beam scanner/locater cum placement system is developed, which scans an area of 10 x 10 mm2 with resolution of 10 to 100 μm in rough scan mode and fine scans selected area with programmable resolution of 2.5 to 25 μm. The scanner acts as slave to the PC in which master GUI grabs the data on serial port and plots the image of X-ray beam. It also analyses and detects the coordinate with maximum intensity. Thus the DAC can be placed at the desired location with an accuracy of 2.5μm anywhere within 10x10 mm2, for performing experiment. Developed system takes only ∼5 minutes to search the beam and a few seconds to place DAC at any the desired location within the scanned area. (author)

  4. Vapor-barrier Vacuum Isolation System

    Science.gov (United States)

    Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

    2014-01-01

    A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

  5. Ribbon Reduces Spiking in Electron-Beam Welding

    Science.gov (United States)

    Olson, R. E.

    1984-01-01

    Spiking in electron-beam welding reduced by placing high-vapor-pressure substance along path of electron beam. Strip of metal having vapor pressure higher than base metal at same temperature placed in slot machined along weld line. Strip vaporizes as beam strikes it, and vapor pressure keeps surface tension from closing off top of channel. Technique used successfully on nickel alloys and aluminum alloys and effective on steel and titanium.

  6. Assessment of computerized treatment planning system accuracy in calculating wedge factors of physical wedged fields for 6 MV photon beams.

    Science.gov (United States)

    Muhammad, Wazir; Maqbool, Muhammad; Shahid, Muhammad; Hussain, Amjad; Tahir, Sajjad; Matiullah; Rooh, Gul; Ahmad, Tanveer; Lee, Sang Hoon

    2011-07-01

    Wedge filters are commonly used in external beam radiotherapy to achieve a uniform dose distribution within the target volume. The main objective of this study was to investigate the accuracy of the beam modifier algorithm of Theraplan plus (TPP version 3.8) treatment planning system and to confirm that either the beam hardening, beam softening and attenuation coefficients along with wedge geometry and measured wedge factor at single depth and multiple fields sizes can be the replacement of wedged profile and wedged cross-sectional data or not. In this regard the effect of beam hardening and beam softening was studied with physical wedges for 6 MV photons. The Normalized Wedge Factors (NWFs) were measured experimentally as well as calculated with the Theraplan plus, as a function of depth and field size in a water phantom for 15°, 30°, 45°, and 60° wedge filters. The beam hardening and softening was determined experimentally by deriving the required coefficients for all wedge angles. The TPP version 3.8 requires wedge transmission factor at single depth and multiple field sizes. Without incorporating the hardening and softening coefficients the percent difference between measured and calculated NFWs was as high as 7%. After the introduction of these parameters into the algorithm, the agreement between measured and TPP (V 3.8) calculated NWFs were improved to within 2 percent for various depths. Similar improvement was observed in TPP version 3.8 while calculating NWFs for various field sizes when the required coefficients were adjusted. In conclusion, the dose calculation algorithm of TPP version 3.8 showed good accuracy for a 6 MV photon beam provided beam hardening and softening parameters are taken into account. From the results, it is also concluded that, the beam hardening, beam softening and attenuation coefficients along with wedge geometry and measured wedge factor at single depth and multiple fields sizes can be the replacement of wedged profile and

  7. Impact of polarized e{sup -} and e{sup +} beams at a future linear collider and a Z-factory. Pt. II. Physics beyond the standard model

    Energy Technology Data Exchange (ETDEWEB)

    Moortgat-Pick, Gudrid [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-12-15

    Polarization of both beams at a future Linear Collider would be ideal for facing both expected and unforeseen challenges in searches for new physics: fixing the chirality of the couplings and enabling the higher precision for the polarization measurement itself as well as for polarization-dependent observables, it provides a powerful tool for studying new physics at the future Linear Collider, such as discovering new particles, analyzing signals model-independently and resolving precisely the underlying model. Techniques and engineering designs for a polarized-positron source are well advanced. Potential constraints concerning luminosity, commissioning and operating issues appear to be under control. This article mainly treats with the impact of polarized beams on physics beyond the Standard Model. (orig.)

  8. Physical insights on the CW on-resonance on-axis focusing in the purely absorptive CW optical beam propagation of intense laser beams in absorbers

    International Nuclear Information System (INIS)

    The saturable absorption, which varies from one concentric shell to another, (namely, the loss decreases with increasing intensity and attenuates the low-intensity 'wings' of the beam more than the high-intensity 'center', thus narrowing a beam propagating through), strips the beam edges which forms a shrinkage aperture. The inward intensity flow does not experience a nonlinear boosting amplification as in the unexpected but numerically predicted self-focusing in SIT since there is not any population inversion in shells closer to the axis. This fact must have been recognized by other investigators when they developed their model in which an aperture stop approximates the stripping of the beam encoding by the non-uniform absorption and then allowed for free space propagation. The stripping and the early stages of an inward flow of intensity can be described perturbatively, but such treatments only describe the onset of the enhancement; the perturbation must be followed by a free space propagation so that the same on-axis self-focusing, obtained by rigorous calculations, occurs. The propagation in free space of a parabolic beam is expressed analytically as an equivalence to the aperture model where absorption induced stripping is followed by a pure diffraction region

  9. Moving contact lines in a pure-vapor atmosphere: a singularity-free description in the sole framework of classical physics

    CERN Document Server

    Rednikov, Alexey

    2012-01-01

    We here show that, even in the absence of "regularizing" microscopic effects (viz. slip at the wall or the disjoining pressure/precursor films), no singularities in fact arise for a moving contact line surrounded by the pure vapor of the liquid considered. There are no evaporation-related singularities either even should the substrate be superheated. We consider, within the lubrication approximation and a classical one-sided model, a contact line advancing/receding at a constant velocity, or immobile, and starting abruptly at a (formally) bare solid surface with a zero or finite contact angle.

  10. Relative biological effectiveness of the 60-MeV therapeutic proton beam at the Institute of Nuclear Physics (IFJ PAN) in Kraków, Poland

    OpenAIRE

    Słonina, Dorota; Biesaga, Beata; Swakoń, Jan; Kabat, Damian; Grzanka, Leszek; Ptaszkiewicz, Marta; Sowa, Urszula

    2014-01-01

    Abstract The aim of the study was to determine the relative biological effectiveness (RBE) of a 60-MeV proton radiotherapy beam at the Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN) in Kraków, the first one to operate in Poland. RBE was assessed at the surviving fractions (SFs) of 0.01, 0.1, and 0.37, for normal human fibroblasts from three cancer patients. The cells were irradiated near the Bragg peak of the pristine beam and at three depths within a 28.4-mm spread-out Br...

  11. Physics potential of a long-baseline neutrino oscillation experiment using a J-PARC neutrino beam and Hyper-Kamiokande

    OpenAIRE

    Asfandiyarov, Ruslan; Blondel, Alain; Bravar, Alessandro; Haegel, Leïla; Haesler, Alexis; Karadzhov, Yordan Ivanov; Korzenev, Alexander; Martin Mari, Carlos; Noah Messomo, Etam Albert; Ravonel Salzgeber, Melody; Rayner, Mark; Scantamburlo, Enrico; Collaboration,, , CMS

    2015-01-01

    Hyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of $CP$ asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this paper, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the...

  12. A novel algorithm for the calculation of physical and biological irradiation quantities in scanned ion beam therapy: the beamlet superposition approach

    Science.gov (United States)

    Russo, G.; Attili, A.; Battistoni, G.; Bertrand, D.; Bourhaleb, F.; Cappucci, F.; Ciocca, M.; Mairani, A.; Milian, F. M.; Molinelli, S.; Morone, M. C.; Muraro, S.; Orts, T.; Patera, V.; Sala, P.; Schmitt, E.; Vivaldo, G.; Marchetto, F.

    2016-01-01

    The calculation algorithm of a modern treatment planning system for ion-beam radiotherapy should ideally be able to deal with different ion species (e.g. protons and carbon ions), to provide relative biological effectiveness (RBE) evaluations and to describe different beam lines. In this work we propose a new approach for ion irradiation outcomes computations, the beamlet superposition (BS) model, which satisfies these requirements. This model applies and extends the concepts of previous fluence-weighted pencil-beam algorithms to quantities of radiobiological interest other than dose, i.e. RBE- and LET-related quantities. It describes an ion beam through a beam-line specific, weighted superposition of universal beamlets. The universal physical and radiobiological irradiation effect of the beamlets on a representative set of water-like tissues is evaluated once, coupling the per-track information derived from FLUKA Monte Carlo simulations with the radiobiological effectiveness provided by the microdosimetric kinetic model and the local effect model. Thanks to an extension of the superposition concept, the beamlet irradiation action superposition is applicable for the evaluation of dose, RBE and LET distributions. The weight function for the beamlets superposition is derived from the beam phase space density at the patient entrance. A general beam model commissioning procedure is proposed, which has successfully been tested on the CNAO beam line. The BS model provides the evaluation of different irradiation quantities for different ions, the adaptability permitted by weight functions and the evaluation speed of analitical approaches. Benchmarking plans in simple geometries and clinical plans are shown to demonstrate the model capabilities.

  13. Effects of high magnetic field on the structure evolution, magnetic and electrical properties of the molecular beam vapor deposited FexNi1−x (0.3≤x<0.8) thin films

    International Nuclear Information System (INIS)

    Nanocrystalline FexNi1−x (in at%, x=0.74, 0.6, 0.55, and 0.3) thin films were prepared on a 25 °C quartz substrate by using a molecular beam vapor deposition method with and without a 6 T magnetic field. The microstructure of the thin films was characterized by energy dispersive x-ray spectroscopy, x-ray diffractometry and transmission electron microscopy. The magnetic and electrical properties of the thin films were examined by a vibrating sample magnetometer and four-point probe method. Results show that the thicknesses of these films with different compositions are 50, 90, 80, and 150 nm, correspondingly. The crystallinity of FexNi1−x (x=0.74 and 0.6) thin films is enhanced, and the γ 〈111〉 orientation degree of the FexNi1−x (x=0.55 and 0.3) thin films increases under a 6 T magnetic field. The grain refinement and defect decrease under 6 T magnetic field are affirmed by TEM. A 6 T magnetic field can help the thin films transform from anisotropy to isotropy. The soft magnetic properties of the FexNi1−x (x=0.74, 0.6, 0.55, and 0.3) thin films are enhanced, and their resistivities decrease under a 6 T magnetic field. - Highlights: ► Crystallinity of thin films increases under a 6 T magnetic field. ► Defects of thin films reduce under 6 T magnetic field. ► Grains are refined and size distribution is narrow under 6 T magnetic field. ► 6 T magnetic field helps thin films transform from anisotropy to isotropy. ► Soft magnetic properties of films are improved under 6 T magnetic field

  14. Analysis of a Beam Made of Physical Nonlinear Material on Nonlinear Elastic Foundation under a Moving Concentrated Load

    OpenAIRE

    E. Mardani

    2008-01-01

    A prismatic beam made of a behaviorally nonlinear material was analyzed under a concentrated load moving with a known velocity on a nonlinear elastic foundation with a reaction the vibration equation of motion was derived using Hamilton principle and Euler Lagrange equation. The amplitude of vibration, circular frequency, bending moment, stress and deflection of the beam can be calculated by the presented solution. Considering the response of the beam, in the sense of its resonance, it was fo...

  15. PHYSICS

    CERN Multimedia

    P. Sphicas

    There have been three physics meetings since the last CMS week: “physics days” on March 27-29, the Physics/ Trigger week on April 23-27 and the most recent physics days on May 22-24. The main purpose of the March physics days was to finalize the list of “2007 analyses”, i.e. the few topics that the physics groups will concentrate on for the rest of this calendar year. The idea is to carry out a full physics exercise, with CMSSW, for select physics channels which test key features of the physics objects, or represent potential “day 1” physics topics that need to be addressed in advance. The list of these analyses was indeed completed and presented in the plenary meetings. As always, a significant amount of time was also spent in reviewing the status of the physics objects (reconstruction) as well as their usage in the High-Level Trigger (HLT). The major event of the past three months was the first “Physics/Trigger week” in Apri...

  16. Computation of integral electron storage ring beam characteristics in the application package DeCA. Version 3.3. A physical model

    International Nuclear Information System (INIS)

    In calculations and optimization of electron storage ring lattices, aside from solving the problem of particle motion stability in the ring and calculating ring structure functions and betatron tune, it is of great importance to determine the integral characteristics such as momentum compaction factor, chromaticity of the lattice, emittance, energy spread, bunch size, beam lifetime, etc. Knowing them, one is able to determine all most important properties which the beam would have in the storage ring, as well as to work out requirements for physical equipment of the ring. In this respect it is of importance to have a possibility of calculating rapidly all the parameters required. This paper describes convenient algorithms for calculating integral beam characteristics in electron storage rings, which are employed in the application package DeCA

  17. Effects of APTEOS content and electron beam irradiation on physical and separation properties of hybrid nylon-66 membranes

    Energy Technology Data Exchange (ETDEWEB)

    Linggawati, A. [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Mohammad, A.W., E-mail: wahabm@eng.ukm.my [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Leo, C.P. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, S.P.S., Penang (Malaysia)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Hybrid nylon-66 membranes were prepared using APTEOS and modified by EB irradiation. Black-Right-Pointing-Pointer APTEOS increase the formation of cellular pores. Black-Right-Pointing-Pointer EB irradiation causes the growth of dense layer. Black-Right-Pointing-Pointer 10 wt% of APTEOS and irradiation at 70 kGy shows satisfactory separation of salt. - Abstract: Nylon-66 contains functional groups which form hydrogen bonds with inorganic silica networks and allow the creation of hybrid membranes. As a typical semicrystalline polymer, nylon-66 can be crosslinked through electron beam (EB) irradiation to form nanofiltration membranes. The effects of {gamma}-aminopropyltriethoxylsilane (APTEOS) and EB irradiation on the physical and separation properties of nylon-66 membranes were studied in this work. Hybrid nylon-66 membranes were prepared by adding an APTEOS solution (5 wt%, 10 wt% and 20 wt%) into nylon-66 which was dissolved in formic acid. Before air drying, membranes were irradiated at 60 kGy, 70 kGy and 80 kGy. More cellular pores were formed in nylon-66 membranes with the addition of APTEOS. However, increased irradiation dose caused the formation of a dense layer in nylon-66 membranes. Crosslinked silica in nylon-66 membranes was confirmed by FT-IR and DMA, while XRD results showed that there was a high degree of crystallinity in some membranes after irradiation. With improvements in membrane pore size and the ratio of membrane thickness to porosity, nylon-66 membrane with 10 wt% of APTEOS irradiated at 70 kGy exhibited satisfactory permeability, excellent removal of neutral solutes and improved rejection of divalent ions.

  18. Effects of APTEOS content and electron beam irradiation on physical and separation properties of hybrid nylon-66 membranes

    International Nuclear Information System (INIS)

    Highlights: ► Hybrid nylon-66 membranes were prepared using APTEOS and modified by EB irradiation. ► APTEOS increase the formation of cellular pores. ► EB irradiation causes the growth of dense layer. ► 10 wt% of APTEOS and irradiation at 70 kGy shows satisfactory separation of salt. - Abstract: Nylon-66 contains functional groups which form hydrogen bonds with inorganic silica networks and allow the creation of hybrid membranes. As a typical semicrystalline polymer, nylon-66 can be crosslinked through electron beam (EB) irradiation to form nanofiltration membranes. The effects of γ-aminopropyltriethoxylsilane (APTEOS) and EB irradiation on the physical and separation properties of nylon-66 membranes were studied in this work. Hybrid nylon-66 membranes were prepared by adding an APTEOS solution (5 wt%, 10 wt% and 20 wt%) into nylon-66 which was dissolved in formic acid. Before air drying, membranes were irradiated at 60 kGy, 70 kGy and 80 kGy. More cellular pores were formed in nylon-66 membranes with the addition of APTEOS. However, increased irradiation dose caused the formation of a dense layer in nylon-66 membranes. Crosslinked silica in nylon-66 membranes was confirmed by FT-IR and DMA, while XRD results showed that there was a high degree of crystallinity in some membranes after irradiation. With improvements in membrane pore size and the ratio of membrane thickness to porosity, nylon-66 membrane with 10 wt% of APTEOS irradiated at 70 kGy exhibited satisfactory permeability, excellent removal of neutral solutes and improved rejection of divalent ions.

  19. Effects of Solutally Dominant Convection on Physical Vapor Transport for a Mixture of Hg2Br2 and Br2 under Microgravity Environments

    International Nuclear Information System (INIS)

    The convective flow structures in the vapor phase on earth are shown to be single unicellular, indicating the solutally dominant convection is important. These findings reflect that the total molar fluxes show asymmetrical patterns in a viewpoint of interfacial distributions. With decreasing the gravitational level form 1 g0 down to 1.0x10-4 g0, the total molar fluxes decay first order exponentially. It is also found that the total molar fluxes decay first order exponentially with increasing the partial pressure of component B, PB (Torr) form 5 Torr up to 400 Torr.. Under microgravity environments less than 1 g0, a diffusive-convection mode is dominant and, results in much uniformity in front of the crystal regions in comparisons with a normal gravity acceleration of 1 g0

  20. SU-E-T-562: Scanned Percent Depth Dose Curve Discrepancy for Photon Beams with Physical Wedge in Place (Varian IX) Using Different Sensitive Volume Ion Chambers

    International Nuclear Information System (INIS)

    Purpose: To investigate and report the discrepancy of scanned percent depth dose (PDD) for photon beams with physical wedge in place when using ion chambers with different sensitive volumes. Methods/Materials: PDD curves of open fields and physical wedged fields (15, 30, 45, and 60 degree wedge) were scanned for photon beams (6MV and 10MV, Varian iX) with field size of 5x5 and 10x10 cm using three common scanning chambers with different sensitive volumes - PTW30013 (0.6cm3), PTW23323 (0.1cm3) and Exradin A16 (0.007cm3). The scanning system software used was OmniPro version 6.2, and the scanning water tank was the Scanditronix Wellhoffer RFA 300.The PDD curves from the three chambers were compared. Results: Scanned PDD curves of the same energy beams for open fields were almost identical between three chambers, but the wedged fields showed non-trivial differences. The largest differences were observed between chamber PTW30013 and Exradin A16. The differences increased as physical wedge angle increased. The differences also increased with depth, and were more pronounced for 6MV beam. Similar patterns were shown for both 5x5 and 10x10 cm field sizes. For open fields, all PDD values agreed with each other within 1% at 10cm depth and within 1.62% at 20 cm depth. For wedged fields, the difference of PDD values between PTW30013 and A16 reached 4.09% at 10cm depth, and 5.97% at 20 cm depth for 6MV with 60 degree physical wedge. Conclusion: We observed a significant difference in scanned PDD curves of photon beams with physical wedge in place obtained when using different sensitive volume ion chambers. The PDD curves scanned with the smallest sensitive volume ion chamber showed significant difference from larger chamber results, beyond 10cm depth. We believe this to be caused by varying response to beam hardening by the wedges

  1. Beam-Beam Effects

    OpenAIRE

    Herr, W; Pieloni, T.

    2016-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  2. Beam-Beam Effects

    CERN Document Server

    Herr, W

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  3. PHYSICS

    CERN Document Server

    D. Acosta

    2010-01-01

    A remarkable amount of progress has been made in Physics since the last CMS Week in June given the exponential growth in the delivered LHC luminosity. The first major milestone was the delivery of a variety of results to the ICHEP international conference held in Paris this July. For this conference, CMS prepared 15 Physics Analysis Summaries on physics objects and 22 Summaries on new and interesting physics measurements that exploited the luminosity recorded by the CMS detector. The challenge was incorporating the largest batch of luminosity that was delivered only days before the conference (300 nb-1 total). The physics covered from this initial running period spanned hadron production measurements, jet production and properties, electroweak vector boson production, and even glimpses of the top quark. Since then, the accumulated integrated luminosity has increased by a factor of more than 100, and all groups have been working tremendously hard on analysing this dataset. The September Physics Week was held ...

  4. Application of proton beam developed at the Institute of Theoretical and Experimental Physics in the treatment of patients with gynecological malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Kiseleva, V.N.; Ruderman, A.I.; Lebedev, A.I. (Akademiya Meditsinskikh Nauk SSSR, Moscow. Onkologicheskij Nauchnyj Tsentr)

    1983-01-01

    Untoward side-effects of exposure of normal tissues surrounding tumor in the course of radiation treatment were avoided due to the use of a proton beam developed at the Institute of Theoretical and Experimental Physics. As a result, no post-treatment complications were observed in the surrounding tissues of the urinary bladder and rectum in 175 cancer patients (tumors of the vulva - 39 and cervix uteri - 136) who received a course of complex radiation treatment and preoperative irradiation.

  5. Collider physics

    International Nuclear Information System (INIS)

    Generally, all experiments with particle physics using energetic beams is collider physics. Today technically collider is taken to mean a particle accelerator in which two beams travelling in opposite directions collide. Many important discoveries in the last 25 years are from collider physics

  6. PHYSICS

    CERN Multimedia

    J. Incandela

    There have been numerous developments in the physics area since the September CMS week. The biggest single event was the Physics/Trigger week in the end of Octo¬ber, whereas in terms of ongoing activities the “2007 analyses” went into high gear. This was in parallel with participation in CSA07 by the physics groups. On the or¬ganizational side, the new conveners of the physics groups have been selected, and a new database for man¬aging physics analyses has been deployed. Physics/Trigger week The second Physics-Trigger week of 2007 took place during the week of October 22-26. The first half of the week was dedicated to working group meetings. The ple¬nary Joint Physics-Trigger meeting took place on Wednesday afternoon and focused on the activities of the new Trigger Studies Group (TSG) and trigger monitoring. Both the Physics and Trigger organizations are now focused on readiness for early data-taking. Thus, early trigger tables and preparations for calibr...

  7. PHYSICS

    CERN Multimedia

    P. Sphicas

    The CPT project came to an end in December 2006 and its original scope is now shared among three new areas, namely Computing, Offline and Physics. In the physics area the basic change with respect to the previous system (where the PRS groups were charged with detector and physics object reconstruction and physics analysis) was the split of the detector PRS groups (the old ECAL-egamma, HCAL-jetMET, Tracker-btau and Muons) into two groups each: a Detector Performance Group (DPG) and a Physics Object Group. The DPGs are now led by the Commissioning and Run Coordinator deputy (Darin Acosta) and will appear in the correspond¬ing column in CMS bulletins. On the physics side, the physics object groups are charged with the reconstruction of physics objects, the tuning of the simulation (in collaboration with the DPGs) to reproduce the data, the provision of code for the High-Level Trigger, the optimization of the algorithms involved for the different physics analyses (in collaboration with the analysis gr...

  8. Significant improvements of the high-field properties of carbon-doped MgB2 films by hot-filament-assisted hybrid physical-chemical vapor deposition using methane as the doping source

    International Nuclear Information System (INIS)

    We report a significant enhancement in upper critical field Hc2 and irreversibility field Hirr in carbon-doped MgB2 films fabricated by hot-filament-assisted hybrid physical-chemical vapor deposition (HFA-HPCVD) using methane as the doping source. For the parallel field, a very large temperature derivative -dHc2parallelab/dT value of 3 T K-1 near Tc was achieved in a heavily doped film with Tc near 28 K. Carbon doping also enhanced flux pinning, resulting in a much higher critical current density in a magnetic field Jc(H) than in undoped samples. The result suggests a more effective doping of carbon into the MgB2 structure and a better connectivity between the carbon-doped MgB2 grains than in previous reports. A clear correlation between the decrease in grain size and the enhancement of Hc2 was observed. (rapid communication)

  9. The Role of Oxygen Partial Pressure in Controlling the Phase Composition of La1- x Sr x Co y Fe1- y O3- δ Oxygen Transport Membranes Manufactured by Means of Plasma Spray-Physical Vapor Deposition

    Science.gov (United States)

    Marcano, D.; Mauer, G.; Sohn, Y. J.; Vaßen, R.; Garcia-Fayos, J.; Serra, J. M.

    2016-04-01

    La0.58Sr0.4Co0.2Fe0.8O3 - δ (LSCF) deposited on a metallic porous support by plasma spray-physical vapor deposition is a promising candidate for oxygen-permeation membranes. Ionic transport properties are regarded to depend on the fraction of perovskite phase present in the membrane. However, during processing, the LSCF powder decomposes into perovskite and secondary phases. In order to improve the ionic transport properties of the membranes, spraying was carried out at different oxygen partial pressures p(O2). It was found that coatings deposited at lower and higher oxygen partial pressures consist of 70% cubic/26% rhombohedral and 61% cubic/35% rhombohedral perovskite phases, respectively. During annealing, the formation of non-perovskite phases is driven by oxygen non-stoichiometry. The amount of oxygen added during spraying can be used to increase the perovskite phase fraction and suppress the formation of non-perovskite phases.

  10. PHYSICS

    CERN Multimedia

    Submitted by

    Physics Week: plenary meeting on physics groups plans for startup (14–15 May 2008) The Physics Objects (POG) and Physics Analysis (PAG) Groups presented their latest developments at the plenary meeting during the Physics Week. In the presentations particular attention was given to startup plans and readiness for data-taking. Many results based on the recent cosmic run were shown. A special Workshop on SUSY, described in a separate section, took place the day before the plenary. At the meeting, we had also two special DPG presentations on “Tracker and Muon alignment with CRAFT” (Ernesto Migliore) and “Calorimeter studies with CRAFT” (Chiara Rovelli). We had also a report from Offline (Andrea Rizzi) and Computing (Markus Klute) on the San Diego Workshop, described elsewhere in this bulletin. Tracking group (Boris Mangano). The level of sophistication of the tracking software increased significantly over the last few months: V0 (K0 and Λ) reconstr...

  11. CaCu3Ti4O12 thin films on conductive oxide electrode: A comparative study between chemical and physical vapor deposition routes

    International Nuclear Information System (INIS)

    Highlights: ► Dielectrics growth and characterization is one of the most hot topics of materials science and microelectronics. ► CaCu3Ti4O12 perovskite, recently, demonstrated to possess peculiar dielectric properties (Science, 2001, 293, 673–676). ► To date no deep discussion on the growth processes, properties and perspective of CCTO thin films has been proposed. ► Our paper is an effective example of interdisciplinarity, since the comparison between PLD and MOCVD has been addressed. ► Great attention has been paid to CaCu3Ti4O12 film/substrate interfaces since dielectric properties are strongly affected. - Abstract: Metal Organic Chemical Vapor Deposition (MOCVD) and Pulsed Laser Deposition (PLD) techniques have been used for the growth of CaCu3Ti4O12 (CCTO) thin films on La0.9Sr1.1NiO4/LaAlO3 (LSNO/LAO) stack. (1 0 0) oriented CCTO films have been formed through both deposition routes and film complete structural and morphological characterizations have been carried out using several techniques (X-ray diffraction, scanning electron microscopy, energy-filtered transmission electron microscopy). The comparative study demonstrated some differences at the CCTO/LSNO interfaces depending on the adopted deposition technique. Chemical/structural modification of the LSNO electrode probably occurred as a function of the different oxygen partial pressure used in the PLD and MOCVD processes.

  12. Comparative study on the effect of electron beam irradiation on the physical properties of ethylene-vinyl acetate copolymer composites

    Science.gov (United States)

    Wang, Bibo; Hong, Ningning; Shi, Yongqian; Wang, Biao; Sheng, Haibo; Song, Lei; Tang, Qinbo; Hu, Yuan

    2014-04-01

    Ethylene-vinyl acetate copolymer (EVA) flame retarded by a combination of cellulose acetate butyrate (CAB) microencapsulated ammonium polyphosphate (MCAPP) and polyamide-6 (PA-6) have been crosslinked by high energy electron beam irradiation. The effect of high energy electron beam irradiation on the crosslinking degree, mechanical, electrical and thermal properties of EVA/MCAPP/PA-6 cable material was studied by gel content, heat extention test, mechanical test, dynamic mechanical analysis, high-insulation resistance meter and thermogravimetric analysis. The gel content and heat extention test results showed that the EVA/MCAPP/PA-6 composites can be easily crosslinked by electron beam irradiation. The tensile strength of EVA composites was drastically increased from 16.2 to maximum 26.2 MPa as the electron beam irradiation dose increases from 0 to 160 kGy. The volatilized products of EVA/MCAPP/PA-6 composites were analyzed and compared by thermogravimetric analysis/infrared spectrometry (TG-FTIR).

  13. Historical Account And Branching To Rarefied Gas Dynamics Of Atomic and Molecular Beams : A Continuing And Fascinating Odyssey Commemorated By Nobel Prizes Awarded To 23 Laureates In Physics And Chemistry

    Science.gov (United States)

    Campargue, Roger

    2005-05-01

    This Historical Account derived in part from D. R. Herschbach was presented as an opening lecture of the Molecular Beam Session organized at the 24th International Symposium on Rarefied Gas Dynamics held in Bari, Italy, in July 2004. The emphasis is on the impressive results due to the molecular beam techniques in the last century. The first section summarizes the historical beam experiments performed by 14 Nobel Prize laureates having used the thermally effusive sources to establish the basic principles of Modern Physics. The second section is on the branching of Molecular Beams to Rarefied Gas Dynamics having permitted to investigate the physics of supersonic free jets and transform the molecular beam techniques. Finally, the last section relates the spectacular molecular beam experiments in helium free jet ultracooling, molecular spectroscopy, chemical reaction dynamics, clustering and modification of low density matter, and biomolecule mass spectrometry, rewarded by nine Nobel Prizes in Chemistry from 1986 to 2002.

  14. Copper vapor laser system development

    International Nuclear Information System (INIS)

    High-power, high-quality, and long-life copper vapor laser (CVL) system has been developed and operated. The system is composed of a small sized CVL oscillator with high beam quality, several high-power CVL amplifiers and related sub-systems such as special resonator optics, beam shaping and propagating optics, and pulse timing controller. Further developments of high-power amplifiers are being conducted for the next R and D targets. In our latest tests, the maximum output power of 480W has been achieved by optimizing discharge circuit conditions. Major-components life-time of more than 2000 hours has been also ensured in long-term CVL amplifier operation tests. Accumulated operation time of more than 700 hours has been achieved without refilling copper source or any maintenance. (author)

  15. Cluster ion beam evaporation

    International Nuclear Information System (INIS)

    Cluster ions can be made by the supercooling due to adiabatic expansion of substances to be vaporized which are ejected from a nozzle. This paper is described on the recent progress of studies concerning the cluster beam. The technique of cluster ion beam has been applied for the studies of thermonuclear plasma, the fabrication of thin films, crystal growth and electronic devices. The density of cluster ion beam is larger than that of atomic ion beam, and the formation of thin films can be easily done in high vacuum. This method is also useful for epitaxial growth. Metallic vapour cluster beam was made by the help of jetting rare gas beam. Various beam sources were developed. The characteristics of these sources were measured and analyzed. (Kato, T.)

  16. PHYSICS

    CERN Document Server

    J. Incandela

    The all-plenary format of the CMS week in Cyprus gave the opportunity to the conveners of the physics groups to present the plans of each physics analysis group for tackling early physics analyses. The presentations were complete, so all are encouraged to browse through them on the Web. There is a wealth of information on what is going on, by whom and on what basis and priority. The CMS week was followed by two CMS “physics events”, the ICHEP08 days and the physics days in July. These were two weeks dedicated to either the approval of all the results that would be presented at ICHEP08, or to the review of all the other Monte-Carlo based analyses that were carried out in the context of our preparations for analysis with the early LHC data (the so-called “2008 analyses”). All this was planned in the context of the beginning of a ramp down of these Monte Carlo efforts, in anticipation of data.  The ICHEP days are described below (agenda and talks at: http://indic...

  17. PHYSICS

    CERN Multimedia

    Joe Incandela

    There have been two plenary physics meetings since the December CMS week. The year started with two workshops, one on the measurements of the Standard Model necessary for “discovery physics” as well as one on the Physics Analysis Toolkit (PAT). Meanwhile the tail of the “2007 analyses” is going through the last steps of approval. It is expected that by the end of January all analyses will have converted to using the data from CSA07 – which include the effects of miscalibration and misalignment. January Physics Days The first Physics Days of 2008 took place on January 22-24. The first two days were devoted to comprehensive re¬ports from the Detector Performance Groups (DPG) and Physics Objects Groups (POG) on their planning and readiness for early data-taking followed by approvals of several recent studies. Highlights of POG presentations are included below while the activities of the DPGs are covered elsewhere in this bulletin. January 24th was devo...

  18. Commissioning with low-intensity beams helps prepare CMS for this year’s physics run. This event is one of the first low-intensity collisions recorded in the CMS detector, during the early hours of 23 April 2016

    CERN Multimedia

    AUTHOR|(CDS)2068005

    2016-01-01

    Commissioning with low-intensity beams helps prepare CMS for this year’s physics run. This event is one of the first low-intensity collisions recorded in the CMS detector, during the early hours of 23 April 2016

  19. Physics

    CERN Document Server

    Cullen, Katherine

    2005-01-01

    Defined as the scientific study of matter and energy, physics explains how all matter behaves. Separated into modern and classical physics, the study attracts both experimental and theoretical physicists. From the discovery of the process of nuclear fission to an explanation of the nature of light, from the theory of special relativity to advancements made in particle physics, this volume profiles 10 pioneers who overcame tremendous odds to make significant breakthroughs in this heavily studied branch of science. Each chapter contains relevant information on the scientist''s childhood, research, discoveries, and lasting contributions to the field and concludes with a chronology and a list of print and Internet references specific to that individual.

  20. Mathematical modeling of copper vapor laser and using it as a pumping source of dye laser

    International Nuclear Information System (INIS)

    A simple 'zero-dimensional' self-consistent mathematical model describing the discharge kinetics and lasing characteristics of copper and copper bromide vapor lasers with neon and hydrogen additives has been developed. The suggested model offers simple mechanisms to explain discharge kinetics mechanisms, different physical processes and hydrogen additive effects on CVL and Cu Br lasers. The model estimates the temporal evolution of discharge voltage and current, population densities, laser beam density, electron temperature and radial distribution of pressure, buffer gas temperature and the influence of the skin effect. (author)

  1. Influence of physical and chemical parameters on the irradiation of aqueous solutions of phenol by electron beam

    International Nuclear Information System (INIS)

    The aim of this work was the study of the influence of different parameters by electron beam irradiation on the decomposition of phenol in aqueous solution. A simulation based on a simplified mechanism emphasized the importance of the oxygenation of the solutions in the removal of phenol by ionisation. A model of the reactor used was proposed from the study of the influence of the beam energy on the decomposition of phenol. Penetration depths of the electrons were determined. Phenol degradation was found to increase with the dose rate. The fraction of the dose into several passages under the electron beam improved the abatement of the phenol. The reoxygenation of the solutions between each passage and the kinetic expressions of irradiation could explain this effect. As expected, the first by-products identified were originated from the reaction of phenol with hydroxyl radicals.

  2. PHYSICS

    CERN Multimedia

    Chris Hill

    2012-01-01

    The months that have passed since the last CMS Bulletin have been a very busy and exciting time for CMS physics. We have gone from observing the very first 8TeV collisions produced by the LHC to collecting a dataset of the collisions that already exceeds that recorded in all of 2011. All in just a few months! Meanwhile, the analysis of the 2011 dataset and publication of the subsequent results has continued. These results come from all the PAGs in CMS, including searches for the Higgs boson and other new phenomena, that have set the most stringent limits on an ever increasing number of models of physics beyond the Standard Model including dark matter, Supersymmetry, and TeV-scale gravity scenarios, top-quark physics where CMS has overtaken the Tevatron in the precision of some measurements, and bottom-quark physics where CMS made its first discovery of a new particle, the Ξ*0b baryon (candidate event pictured below). Image 2:  A Ξ*0b candidate event At the same time POGs and PAGs...

  3. PHYSICS

    CERN Multimedia

    Guenther Dissertori

    The time period between the last CMS week and this June was one of intense activity with numerous get-together targeted at addressing specific issues on the road to data-taking. The two series of workshops, namely the “En route to discoveries” series and the “Vertical Integration” meetings continued.   The first meeting of the “En route to discoveries” sequence (end 2007) had covered the measurements of the Standard Model signals as necessary prerequisite to any claim of signals beyond the Standard Model. The second meeting took place during the Feb CMS week and concentrated on the commissioning of the Physics Objects, whereas the third occurred during the April Physics Week – and this time the theme was the strategy for key new physics signatures. Both of these workshops are summarized below. The vertical integration meetings also continued, with two DPG-physics get-togethers on jets and missing ET and on electrons and photons. ...

  4. PHYSICS

    CERN Multimedia

    D. Acosta

    2011-01-01

    Since the last CMS Week, all physics groups have been extremely active on analyses based on the full 2010 dataset, with most aiming for a preliminary measurement in time for the winter conferences. Nearly 50 analyses were approved in a “marathon” of approval meetings during the first two weeks of March, and the total number of approved analyses reached 90. The diversity of topics is very broad, including precision QCD, Top, and electroweak measurements, the first observation of single Top production at the LHC, the first limits on Higgs production at the LHC including the di-tau final state, and comprehensive searches for new physics in a wide range of topologies (so far all with null results unfortunately). Most of the results are based on the full 2010 pp data sample, which corresponds to 36 pb-1 at √s = 7 TeV. This report can only give a few of the highlights of a very rich physics program, which is listed below by physics group...

  5. Enhanced performance of dye-sensitized solar cells with TiO2 blocking layers and Pt counter electrodes prepared by physical vapor deposition (PVD)

    International Nuclear Information System (INIS)

    Titanium dioxide (TiO2) thin films as block layers are prepared by DC reactive magnetron sputtering. X-ray diffraction (XRD) and TEM-(SAED) analyses of the films reveal that they are polycrystalline in nature and have tetragonal structure with preferred orientation along the (101) direction. The surface morphological studies by FESEM and AFM reveal the uniform surface coverage of the grains on the surface of the films. An optical transmittance value of 80% in the visible light region with the optical band gap value of 3.2 eV is measured. This sputtered TiO2 thin film is used as a blocking layer over which a thick layer of TiO2 of about 10 μm was prepared using TiO2 paste and this stack is used as the photoanode of a DSSC cell. Electron beam evaporated platinum thin film on FTO coated glass substrate is used as counter electrode. The performance of the cell with a Voc of 0.698 V, a Jsc of 6.8 mAcm−2 and an efficiency of 4.2% was achieved

  6. Time average neutralized migma: A colliding beam/plasma hybrid physical state as aneutronic energy source — A review

    Science.gov (United States)

    Maglich, Bogdan C.

    1988-08-01

    A D + beam of kinetic energy Ti = 0.7 MeV was stored in a "simple mirror" magnetic field as self-colliding orbits or migma and neutralized by ambient, oscillating electrons whose bounce frequencies were externally controlled. Space charge density was exceeded by an order of magnitude without instabilities. Three nondestructive diagnostic methods allowed measurements of ion orbit distribution, ion storage times, ion energy distribution, nuclear reaction rate, and reaction product spectrum. Migma formed a disc 20 cm in diameter and 0.5 cm thick. Its ion density was sharply peaked in the center; the ion-to-electron temperature ratio was TiTe ˜ 10 3; ion-electron temperature equilibrium was never reached. The volume average and central D + density were n = 3.2 × 10 9 cm -3 and nc = 3 × 10 10 cm -3 respectively, compared to the space charge limit density nsc = 4 × 10 8 cm -3. The energy confinement time was τc = 20-30 s, limited by the change exchange reactions with the residual gas in the vacuum (5 × 10 -9 Torr). The ion energy loss rate was 1.4 keV/s. None of the instabilities that were observed in mirrors at several orders of magnitude lower density occurred. The proton energy spectrum for dd + d → T + p + 4 MeV shows that dd collided at an average crossing angle of 160°. Evidence for exponential density buildup has also been observed. Relative to Migma III results and measured in terms of the product of ion energy E, density n, and confinement time τ, device performance was improved by a factor of 500. Using the central fast ion density, we obtained the triple product: Tnτ ≅ 4 × 10 14 keV s cm -3, which is greater than that of the best fusion devices. The luminosity (collision rate per unit cross section) was ˜ 10 29 cm -2s -1, with o.7 A ion current through the migma center. The stabilizing features of migma are: (1) large Larmor radius; (2) small canonical angular momentum; (3) short axial length z (disc shape); (4) nonadiabatic motions in r and z

  7. Improve the physical and chemical properties of biocompatible polymer material by MeV He ion beam

    International Nuclear Information System (INIS)

    There is a high interest in improving the hydrophilicity of polymer surfaces due to their wide use for technological purposes. In this study Ultra High Molecular Weight Polyethylene (UHMWPE) as a biocompatible material was bombarded with 1 MeV He ions to the fluences ranging from 1×1013 to 5×1014 cm−2. The pristine and ion beam modified samples were investigated by photoluminescence (PL), ultraviolet–visible (UV–vis) spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The changes of wettability and surface free energy were determined by the contact angle measurements. The obtained results showed that the ion bombardment induced decrease in integrated luminescence intensity and decrease in the transmittance with increase of ion fluence as well. This is might be attributed to degradation of polymer surface and/or creation of new electronic levels in the forbidden gap. The FTIR spectral studies indicate that the ion beam induces chemical modifications within the bombarded UHMWPE. Formation of carbonyl groups (C=O) on the polymer surface was studied. Direct relationship of the wettability and surface free energy of the bombarded polymer with the ion fluences was observed. - Highlights: ► Effect of 1 MeV He-ion bombardment on the surface properties of UHMWPE was studied. ► Change in the surface layer composition of UHMWPE due ion beam has been investigated. ► Ion beam bombardment improves the surface free energy of UHMWPE.

  8. Real-time optical-fibre luminescence dosimetry for radiotherapy: physical characteristics and applications in photon beams

    DEFF Research Database (Denmark)

    Aznar, M.C.; Andersen, C.E.; Bøtter-Jensen, L.;

    2004-01-01

    A new optical-fibre radiation dosimeter system, based on radioluminescence and optically stimulated luminescence from carbon-doped aluminium oxide, was developed and tested in clinical photon beams. This prototype offers several features, such as a small detector (1 x 1 x 2 mm), high sensitivity,...

  9. Stratospheric water vapor feedback

    OpenAIRE

    Dessler, A. E.; Schoeberl, M. R.; Wang, T.; Davis, S M; K. H. Rosenlof

    2013-01-01

    We show observational evidence for a stratospheric water vapor feedback—a warmer climate increases stratospheric water vapor, and because stratospheric water vapor is itself a greenhouse gas, this leads to further warming. An estimate of its magnitude from a climate model yields a value of +0.3 W/(m2⋅K), suggesting that this feedback plays an important role in our climate system.

  10. PHYSICS

    CERN Multimedia

    the PAG conveners

    2011-01-01

    The delivered LHC integrated luminosity of more than 1 inverse femtobarn by summer and more than 5 by the end of 2011 has been a gold mine for the physics groups. With 2011 data, we have submitted or published 14 papers, 7 others are in collaboration-wide review, and 75 Physics Analysis Summaries have been approved already. They add to the 73 papers already published based on the 2010 and 2009 datasets. Highlights from each physics analysis group are described below. Heavy ions Many important results have been obtained from the first lead-ion collision run in 2010. The published measurements include the first ever indications of Υ excited state suppression (PRL synopsis), long-range correlation in PbPb, and track multiplicity over a wide η range. Preliminary results include the first ever measurement of isolated photons (showing no modification), J/ψ suppression including the separation of the non-prompt component, further study of jet fragmentation, nuclear modification factor...

  11. PHYSICS

    CERN Multimedia

    C. Hill

    2012-01-01

      The period since the last CMS Bulletin has been historic for CMS Physics. The pinnacle of our physics programme was an observation of a new particle – a strong candidate for a Higgs boson – which has captured worldwide interest and made a profound impact on the very field of particle physics. At the time of the discovery announcement on 4 July, 2012, prominent signals were observed in the high-resolution H→γγ and H→ZZ(4l) modes. Corroborating excess was observed in the H→W+W– mode as well. The fermionic channel analyses (H→bb, H→ττ), however, yielded less than the Standard Model (SM) expectation. Collectively, the five channels established the signal with a significance of five standard deviations. With the exception of the diphoton channel, these analyses have all been updated in the last months and several new channels have been added. With improved analyses and more than twice the i...

  12. PHYSICS

    CERN Document Server

    Darin Acosta

    2010-01-01

    The collisions last year at 900 GeV and 2.36 TeV provided the long anticipated collider data to the CMS physics groups. Quite a lot has been accomplished in a very short time. Although the delivered luminosity was small, CMS was able to publish its first physics paper (with several more in preparation), and commence the commissioning of physics objects for future analyses. Many new performance results have been approved in advance of this CMS Week. One remarkable outcome has been the amazing agreement between out-of-the-box data with simulation at these low energies so early in the commissioning of the experiment. All of this is testament to the hard work and preparation conducted beforehand by many people in CMS. These analyses could not have happened without the dedicated work of the full collaboration on building and commissioning the detector, computing, and software systems combined with the tireless work of many to collect, calibrate and understand the data and our detector. To facilitate the efficien...

  13. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    The Physics Groups are actively engaged on analyses of the first data from the LHC at 7 TeV, targeting many results for the ICHEP conference taking place in Paris this summer. The first large batch of physics approvals is scheduled for this CMS Week, to be followed by four more weeks of approvals and analysis updates leading to the start of the conference in July. Several high priority analysis areas were organized into task forces to ensure sufficient coverage from the relevant detector, object, and analysis groups in the preparation of these analyses. Already some results on charged particle correlations and multiplicities in 7 TeV minimum bias collisions have been approved. Only one small detail remains before ICHEP: further integrated luminosity delivered by the LHC! Beyond the Standard Model measurements that can be done with these data, the focus changes to the search for new physics at the TeV scale and for the Higgs boson in the period after ICHEP. Particle Flow The PFT group is focusing on the ...

  14. PHYSICS

    CERN Multimedia

    C. Hill

    2012-01-01

      2012 has started off as a very busy year for the CMS Physics Groups. Planning for the upcoming higher luminosity/higher energy (8 TeV) operation of the LHC and relatively early Rencontres de Moriond are the high-priority activities for the group at the moment. To be ready for the coming 8-TeV data, CMS has made a concerted effort to perform and publish analyses on the 5 fb−1 dataset recorded in 2011. This has resulted in the submission of 16 papers already, including nine on the search for the Higgs boson. In addition, a number of preliminary results on the 2011 dataset have been released to the public. The Exotica and SUSY groups approved several searches for new physics in January, such as searches for W′ and exotic highly ionising particles. These were highlighted at a CERN seminar given on 24th  January. Many more analyses, from all the PAGs, including the newly formed SMP (Standard Model Physics) and FSQ (Forward and Small-x QCD), were approved in February. The ...

  15. PHYSICS

    CERN Multimedia

    L. Demortier

    Physics-wise, the CMS week in December was dominated by discussions of the analyses that will be carried out in the “next six months”, i.e. while waiting for the first LHC collisions.  As presented in December, analysis approvals based on Monte Carlo simulation were re-opened, with the caveat that for this work to be helpful to the goals of CMS, it should be carried out using the new software (CMSSW_2_X) and associated samples.  By the end of the week, the goal for the physics groups was set to be the porting of our physics commissioning methods and plans, as well as the early analyses (based an integrated luminosity in the range 10-100pb-1) into this new software. Since December, the large data samples from CMSSW_2_1 were completed. A big effort by the production group gave a significant number of events over the end-of-year break – but also gave out the first samples with the fast simulation. Meanwhile, as mentioned in December, the arrival of 2_2 meant that ...

  16. Intense positron beams: linacs

    International Nuclear Information System (INIS)

    Beams of monoenergetic positrons with energies of a few eV to many keV have been used in experiments in atomic physics, solid-state physics and materials science. The production of positron beams from a new source, an electron linac, is described. Intense, pulsed beams of low-energy positrons were produced by a high-energy beam from an electron linac. The production efficiency, moderator geometry, beam spot size and other positron beam parameters were determined for electrons with energies from 60 to 120 MeV. Low-energy positron beams produced with a high-energy electron linac can be of much higher intensity than those beams currently derived from radioactive sources. These higher intensity beams will make possible positron experiments previously infeasible. 10 references, 1 figure

  17. Structural properties of In{sub 2}Se{sub 3} precursor layers deposited by spray pyrolysis and physical vapor deposition for CuInSe{sub 2} thin-film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Figueroa, P. [Department of Electrical Engineering (SEES), Cinvestav-Zacatenco, 2508 Av. IPN, 07360 Mexico City (Mexico); IMN, UMR 6502, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes Cedex 3 (France); Painchaud, T.; Lepetit, T.; Harel, S.; Arzel, L. [IMN, UMR 6502, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes Cedex 3 (France); Yi, Junsin, E-mail: yi@skku.ac.kr [School of Information and Communication Engineering, 2066 Seobu-ro, Jangan-gu, 440-746 Suwon (Korea, Republic of); Barreau, N. [IMN, UMR 6502, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes Cedex 3 (France); Velumani, S., E-mail: velu@cinvestav.mx [Department of Electrical Engineering (SEES), Cinvestav-Zacatenco, 2508 Av. IPN, 07360 Mexico City (Mexico); School of Information and Communication Engineering, 2066 Seobu-ro, Jangan-gu, 440-746 Suwon (Korea, Republic of)

    2015-07-31

    The structural properties of In{sub 2}Se{sub 3} precursor thin films grown by chemical spray pyrolysis (CSP) and physical vapor deposition (PVD) methods were compared. This is to investigate the feasibility to substitute PVD process of CuInSe{sub 2} (CISe) films by CSP films as precursor layer, thus decreasing the production cost by increasing material-utilization efficiency. Both films of 1 μm thickness were deposited at the same substrate temperature of 380 °C. X-ray diffraction and Raman spectra confirm the formation of γ-In{sub 2}Se{sub 3} crystalline phase for both films. The PVD and CSP films exhibited (110) and (006) preferred orientations, respectively. The PVD films showed a smaller full width at half maximum value (0.09°) compared with CSP layers (0.1°). Films with the same crystalline phase but with different orientations are normally used in the preparation of high quality CISe films by 3-stage process. Scanning electron microscope cross-section images showed an important difference in grain size with well-defined larger grains of size 1–2 μm in the PVD films as compared to CSP layers (600 nm). Another important characteristic that differentiates the two precursor films is the oxygen contamination. X-ray photoelectron spectroscopy showed the presence of oxygen in CSP films. The oxygen atoms could be bonded to indium by replacing Se vacancies, which are formed during CSP deposition. Taking account of the obtained results, such CSP films can be used as precursor layer in a PVD process in order to produce CISe absorber films. - Highlights: • To find the intricacies involved in spray pyrolysis (CSP) and physical vapor (PVD) deposition. • Comparison of CSP and PVD film formations — especially in structural properties. • Feasibility to substitute CSP (cheaper) films for PVD in the manufacturing process. • Decreasing the global production cost of Cu(In,Ga)Se{sub 2} devices in the 3-stage process.

  18. A simple and fast physics-based analytical method to calculate therapeutic and stray doses from external beam, megavoltage x-ray therapy

    Science.gov (United States)

    Jagetic, Lydia J.; Newhauser, Wayne D.

    2015-06-01

    State-of-the-art radiotherapy treatment planning systems provide reliable estimates of the therapeutic radiation but are known to underestimate or neglect the stray radiation exposures. Most commonly, stray radiation exposures are reconstructed using empirical formulas or lookup tables. The purpose of this study was to develop the basic physics of a model capable of calculating the total absorbed dose both inside and outside of the therapeutic radiation beam for external beam photon therapy. The model was developed using measurements of total absorbed dose in a water-box phantom from a 6 MV medical linear accelerator to calculate dose profiles in both the in-plane and cross-plane direction for a variety of square field sizes and depths in water. The water-box phantom facilitated development of the basic physical aspects of the model. RMS discrepancies between measured and calculated total absorbed dose values in water were less than 9.3% for all fields studied. Computation times for 10 million dose points within a homogeneous phantom were approximately 4 min. These results suggest that the basic physics of the model are sufficiently simple, fast, and accurate to serve as a foundation for a variety of clinical and research applications, some of which may require that the model be extended or simplified based on the needs of the user. A potentially important advantage of a physics-based approach is that the model is more readily adaptable to a wide variety of treatment units and treatment techniques than with empirical models.

  19. PHYSICS

    CERN Multimedia

    Christopher Hill

    2013-01-01

    Since the last CMS Bulletin, the CMS Physics Analysis Groups have completed more than 70 new analyses, many of which are based on the complete Run 1 dataset. In parallel the Snowmass whitepaper on projected discovery potential of CMS for HL-LHC has been completed, while the ECFA HL-LHC future physics studies has been summarised in a report and nine published benchmark analyses. Run 1 summary studies on b-tag and jet identification, quark-gluon discrimination and boosted topologies have been documented in BTV-13-001 and JME-13-002/005/006, respectively. The new tracking alignment and performance papers are being prepared for submission as well. The Higgs analysis group produced several new results including the search for ttH with H decaying to ZZ, WW, ττ+bb (HIG-13-019/020) where an excess of ~2.5σ is observed in the like-sign di-muon channel, and new searches for high-mass Higgs bosons (HIG-13-022). Search for invisible Higgs decays have also been performed both using the associ...

  20. PHYSICS

    CERN Document Server

    C. Hill

    2013-01-01

    In the period since the last CMS Bulletin, the LHC – and CMS – have entered LS1. During this time, CMS Physics Analysis Groups have performed more than 40 new analyses, many of which are based on the complete 8 TeV dataset delivered by the LHC in 2012 (and in some cases on the full Run 1 dataset). These results were shown at, and well received by, several high-profile conferences in the spring of 2013, including the inaugural meeting of the Large Hadron Collider    Physics Conference (LHCP) in Barcelona, and the 26th International Symposium on Lepton Photon Interactions at High Energies (LP) in San Francisco. In parallel, there have been significant developments in preparations for Run 2 of the LHC and on “future physics” studies for both Phase 1 and Phase 2 upgrades of the CMS detector. The Higgs analysis group produced five new results for LHCP including a new H-to-bb search in VBF production (HIG-13-011), ttH with H to γ&ga...

  1. PHYSICS

    CERN Multimedia

    C. Hill

    2013-01-01

    The period since the last CMS bulletin has seen the end of proton collisions at a centre-of-mass energy 8 TeV, a successful proton-lead collision run at 5 TeV/nucleon, as well as a “reference” proton run at 2.76 TeV. With these final LHC Run 1 datasets in hand, CMS Physics Analysis Groups have been busy analysing these data in preparation for the winter conferences. Moreover, despite the fact that the pp run only concluded in mid-December (and there was consequently less time to complete data analyses), CMS again made a strong showing at the Rencontres de Moriond in La Thuile (EW and QCD) where nearly 40 new results were presented. The highlight of these preliminary results was the eagerly anticipated updated studies of the properties of the Higgs boson discovered in July of last year. Meanwhile, preparations for Run 2 and physics performance studies for Phase 1 and Phase 2 upgrade scenarios are ongoing. The Higgs analysis group produced updated analyses on the full Run 1 dataset (~25 f...

  2. PHYSICS

    CERN Multimedia

    J. D'Hondt

    The Electroweak and Top Quark Workshop (16-17th of July) A Workshop on Electroweak and Top Quark Physics, dedicated on early measurements, took place on 16th-17th July. We had more than 40 presentations at the Workshop, which was an important milestone for 2007 physics analyses in the EWK and TOP areas. The Standard Model has been tested empirically by many previous experiments. Observables which are nowadays known with high precision will play a major role for data-based CMS calibrations. A typical example is the use of the Z to monitor electron and muon reconstruction in di-lepton inclusive samples. Another example is the use of the W mass as a constraint for di-jets in the kinematic fitting of top-quark events, providing information on the jet energy scale. The predictions of the Standard Model, for what concerns proton collisions at the LHC, are accurate to a level that the production of W/Z and top-quark events can be used as a powerful tool to commission our experiment. On the other hand the measure...

  3. Physics design of a 100 keV acceleration grid system for the diagnostic neutral beam for international tokamak experimental reactor

    International Nuclear Information System (INIS)

    This paper describes the physics design of a 100 keV, 60 A H- accelerator for the diagnostic neutral beam (DNB) for international tokamak experimental reactor (ITER). The accelerator is a three grid system comprising of 1280 apertures, grouped in 16 groups with 80 apertures per beam group. Several computer codes have been used to optimize the design which follows the same philosophy as the ITER Design Description Document (DDD) 5.3 and the 1 MeV heating and current drive beam line [R. Hemsworth, H. Decamps, J. Graceffa, B. Schunke, M. Tanaka, M. Dremel, A. Tanga, H. P. L. De Esch, F. Geli, J. Milnes, T. Inoue, D. Marcuzzi, P. Sonato, and P. Zaccaria, Nucl. Fusion 49, 045006 (2009)]. The aperture shapes, intergrid distances, and the extractor voltage have been optimized to minimize the beamlet divergence. To suppress the acceleration of coextracted electrons, permanent magnets have been incorporated in the extraction grid, downstream of the cooling water channels. The electron power loads on the extractor and the grounded grids have been calculated assuming 1 coextracted electron per ion. The beamlet divergence is calculated to be 4 mrad. At present the design for the filter field of the RF based ion sources for ITER is not fixed, therefore a few configurations of the same have been considered. Their effect on the transmission of the electrons and beams through the accelerator has been studied. The OPERA-3D code has been used to estimate the aperture offset steering constant of the grounded grid and the extraction grid, the space charge interaction between the beamlets and the kerb design required to compensate for this interaction. All beamlets in the DNB must be focused to a single point in the duct, 20.665 m from the grounded grid, and the required geometrical aimings and aperture offsets have been calculated.

  4. Realisation and characterization of organic photovoltaic cells obtained by physical vapor deposition; Realisation et caracterisation de cellules photovoltaiques organiques obtenues par depot physique

    Energy Technology Data Exchange (ETDEWEB)

    Brousse, B.

    2004-12-01

    This work deals with the synthesis and the characterization of low cost organic solar cells, contributing to the development of renewable energies, and able to feed devices as portable telephone...In particular, we have contributed to the development of an experimentation bench for the obtention of different structures (bilayers, interpenetrated and multilayers) of solar cells from different donor-acceptor couples of small molecules. After having presented a retrospective of the physical phenomena and of the mechanisms involved, as well as those of the photovoltaic principle in the organic materials, we describe the technological steps allowing to carry out the solar cells. The materials (organic and metallic) are deposited on thin films (of 30 to 100 nm) spin-coating (PEDOT-PSS) or by vacuum evaporation (small molecules and metallization of the cathode) on a glass substrate covered by a conducting and a semi-transparent ITO layer constituting the anode. The structures carried out have been characterized in air in obscurity and under illumination by curves I(V), by capacitive measurements and IPCE spectra (photocurrent spectra). Different donor-acceptor couples (phthalocyanine/C60, oligomer of thiophene/C60 and phthalocyanine/perylene derivative) have been tested by various configurations: p-n heterojunctions distributed or not in the volume. The obtained results are better for the bilayers structures on account of the granularity of the C60. This characteristics have allowed us to carry out an efficient multilayer structure (CuPc/C60). In order to resolve the problem of the deposit of the C60, we have tested another acceptor molecule: a derived compound of the perylene (PPTC). Complementary studies have been carried out by the ionic implantation of the active layers, allowing both a densification and a doping of these ones; the encapsulation of the compounds by polyimide VDP (gaseous phase polymerization) have been evaluated. With this technique, we have developed

  5. Petroleum Vapor - Field Technical

    Science.gov (United States)

    The screening approach being developed by EPA OUST to evaluate petroleum vapor intrusion (PVI) requires information that has not be routinely collected in the past at vapor intrusion sites. What is the best way to collect this data? What are the relevant data quality issues and ...

  6. Water vapor pressure calculation.

    Science.gov (United States)

    Hall, J R; Brouillard, R G

    1985-06-01

    Accurate calculation of water vapor pressure for systems saturated with water vapor can be performed using the Goff-Gratch equation. A form of the equation that can be adapted for computer programming and for use in electronic databases is provided. PMID:4008425

  7. The impact of new water vapor spectroscopy on satellite retrievals

    OpenAIRE

    Maurellis, A. N.; Lang, R.; Williams, J. E.; W. J. van der Zande; Smith, K; D. A. Newnham; Tennyson, J.; Tolchenov, R. N.

    2003-01-01

    Water vapor, arguably the most important trace gas constituent of Earth atmospheric physics, is also both a retrieval goal and a hindrance in the retrievals of other trace gases from nadir-measuring satellite spectrometers. This is because the atmospherically-attenuated solar spectrum in the visible and shortwave infrared is littered with water vapor bands. The recent plethora of water vapor spectroscopy databases in this spectral region has prompted us to study their utility in satellite ret...

  8. Plasma Spray Physical Vapor Deposition of La1- x Sr x Co y Fe1- y O3-δ Thin-Film Oxygen Transport Membrane on Porous Metallic Supports

    Science.gov (United States)

    Jarligo, Maria Ophelia; Mauer, Georg; Bram, Martin; Baumann, Stefan; Vaßen, Robert

    2014-01-01

    Plasma spray physical vapor deposition (PS-PVD) is a very promising route to manufacture ceramic coatings, combining the efficiency of thermal spray processes and characteristic features of thin PVD coatings. Recently, this technique has been investigated to effectively deposit dense thin films of perovskites particularly with the composition of La0.58Sr0.4Co0.2Fe0.8O3-δ (LSCF) for application in gas separation membranes. Furthermore, asymmetric type of membranes with porous metallic supports has also attracted research attention due to the advantage of good mechanical properties suitable for use at high temperatures and high permeation rates. In this work, both approaches are combined to manufacture oxygen transport membranes made of gastight LSCF thin film by PS-PVD on porous NiCoCrAlY metallic supports. The deposition of homogenous dense thin film is challenged by the tendency of LSCF to decompose during thermal spray processes, irregular surface profile of the porous metallic substrate and crack and pore-formation in typical ceramic thermal spray coatings. Microstructure formation and coating build-up during PS-PVD as well as the annealing behavior at different temperatures of LSCF thin films were investigated. Finally, measurements of leak rates and oxygen permeation rates at elevated temperatures show promising results for the optimized membranes.

  9. Beam-beam effects

    Energy Technology Data Exchange (ETDEWEB)

    Zholents, A.

    1994-12-01

    The term beam-beam effects is usually used to designate different phenomena associated with interactions of counter-rotating beams in storage rings. Typically, the authors speak about beam-beam effects when such interactions lead to an increase of the beam core size or to a reduction of the beam lifetime or to a growth of particle`s population in the beam halo and a correspondent increase of the background. Although observations of beam-beam effects are very similar in most storage rings, it is very likely that every particular case is largely unique and machine-dependent. This constitutes one of the problems in studying the beam-beam effects, because the experimental results are often obtained without characterizing a machine at the time of the experiment. Such machine parameters as a dynamic aperture, tune dependencies on amplitude of particle oscillations and energy, betatron phase advance between the interaction points and some others are not well known, thus making later analysis uncertain. The authors begin their discussion with demonstrations that beam-beam effects are closely related to non linear resonances. Then, they will show that a non linearity of the space charge field is responsible for the excitation of these resonances. After that, they will consider how beam-beam effects could be intensified by machine imperfections. Then, they will discuss a leading mechanism for the formation of the beam halo and will describe a new technique for beam tails and lifetime simulations. They will finish with a brief discussion of the coherent beam-beam effects.

  10. PHYSICS

    CERN Document Server

    V.Ciulli

    2011-01-01

    The main programme of the Physics Week held between 16th and 20th May was a series of topology-oriented workshops on di-leptons, di-photons, inclusive W, and all-hadronic final states. The goal of these workshops was to reach a common understanding for the set of objects (ID, cleaning...), the handling of pile-up, calibration, efficiency and purity determination, as well as to revisit critical common issues such as the trigger. Di-lepton workshop Most analysis groups use a di-lepton trigger or a combination of single and di-lepton triggers in 2011. Some groups need to collect leptons with as low PT as possible with strong isolation and identification requirements as for Higgs into WW at low mass, others with intermediate PT values as in Drell-Yan studies, or high PT as in the Exotica group. Electron and muon reconstruction, identification and isolation, was extensively described in the workshop. For electrons, VBTF selection cuts for low PT and HEEP cuts for high PT were discussed, as well as more complex d...

  11. A High-Pressure Polarized $^3$He Gas Target for Nuclear Physics Experiments Using A Polarized Photon Beam

    CERN Document Server

    Ye, Q; Chen, W; Gao, H; Zheng, W; Zong, X; Averett, T; Cates, G D; Tobias, W A

    2009-01-01

    Following the first experiment on three-body photodisintegration of polarized $^3$He utilizing circularly polarized photons from High Intensity Gamma Source (HI$\\gamma$S) at Duke Free Electron Laser Laboratory (DFELL), a new high-pressure polarized $^3$He target cell made of pyrex glass coated with a thin layer of sol-gel doped with aluminum nitrate nonahydrate has been built in order to reduce photon beam induced backgrounds. The target is based on the technique of spin-exchange optical pumping of hybrid rubidium and potassium and the highest polarization achieved is $\\sim$62\\% determined from both NMR-AFP and EPR polarimetry. The $X$ parameter is estimated to be $0.17\\pm0.06$ and the performance of the target is in good agreement with theoretical predictions. We also present beam test results from this new target cell and the comparison with the GE180 $^3$He target cell used previously at HI$\\gamma$S. This is the first time that sol-gel coating technique has been used in a polarized $^3$He target for nuclea...

  12. Improve the physical and chemical properties of biocompatible polymer material by MeV He ion beam

    Science.gov (United States)

    Abdul-Kader, A. M.; El-Gendy, Y. A.; Al-Rashdy, Awad A.

    2012-07-01

    There is a high interest in improving the hydrophilicity of polymer surfaces due to their wide use for technological purposes. In this study Ultra High Molecular Weight Polyethylene (UHMWPE) as a biocompatible material was bombarded with 1 MeV He ions to the fluences ranging from 1×1013 to 5×1014 cm-2. The pristine and ion beam modified samples were investigated by photoluminescence (PL), ultraviolet-visible (UV-vis) spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The changes of wettability and surface free energy were determined by the contact angle measurements. The obtained results showed that the ion bombardment induced decrease in integrated luminescence intensity and decrease in the transmittance with increase of ion fluence as well. This is might be attributed to degradation of polymer surface and/or creation of new electronic levels in the forbidden gap. The FTIR spectral studies indicate that the ion beam induces chemical modifications within the bombarded UHMWPE. Formation of carbonyl groups (C=O) on the polymer surface was studied. Direct relationship of the wettability and surface free energy of the bombarded polymer with the ion fluences was observed.

  13. Vapor pressures of dimethylcadmium, trimethylbismuth, and tris(dimethylamino)antimony

    Czech Academy of Sciences Publication Activity Database

    Morávek, Pavel; Fulem, Michal; Pangrác, Jiří; Hulicius, Eduard; Růžička, K.

    2013-01-01

    Roč. 360, Dec (2013), s. 106-110. ISSN 0378-3812 R&D Projects: GA ČR GA13-15286S; GA MŠk(CZ) LM2011026 Institutional support: RVO:68378271 Keywords : vapor pressure * dimethylcadmium * trimethylbismuth * tris(dimethylamino)antimony * sublimation and vaporization enthalpy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.241, year: 2013

  14. Investigation on the Influence of Different Laser Beam Intensity Distributions on Keyhole Geometry During Laser Welding

    Science.gov (United States)

    Volpp, J.

    An analytical quasi-static model of the keyhole during laser deep penetration welding is introduced. This model is used to calculate the keyhole geometry depending on spatial laser beam intensity. Keyhole shapes can be found solving the energy and pressure equations. All necessary physical effects like Fresnel and plasma absorption, heat conduction and vaporization are implemented in the model. For evaluation a Gaussian and a top hat beam profile were used. Experimental measurements of the keyhole shape using copper inlays in aluminum base material show good agreement with the results of the modeling.

  15. Spacelab 3 vapor crystal growth experiment

    Science.gov (United States)

    Schnepple, W.; Vandenberg, L.; Skinner, N.; Ortale, C.

    1987-01-01

    The Space Shuttle Challenger, with Spacelab 3 as its payload, was launched into orbit April 29, 1985. The mission, number 51-B, emphasized materials processing in space, although a wide variety of experiments in other disciplines were also carried onboard. One of the materials processing experiments on this flight is described, specifically the growth of single crystals of mercuric iodide by physical vapor transport.

  16. Effect of Anorganic Substance on Physical Properties of Poly (Butylene Succinate -co- Adipate) Irradiated by Electron Beam

    International Nuclear Information System (INIS)

    Poly(butylene succinate-co-adipate), PBSA were electron beam irradiated in the presence of inorganic materials. The samples gave high gel fraction by irradiation in the presence of 2% silicon dioxide and 2% carbon black. It was found that addition of carbon black (CB) was effective for improving the heat stability of the sample. This is because of three-dimensional carbon black- polymer networks. Irradiated PBSA sheets broke immediately at 110 oC with load 6.67 kgf/cm2, while irradiated the same sample mixed with 2% carbon black did not break at the same condition. Biodegradability of crosslinked PBSA by soil burial tests was accelerated by addition of carbon black. (author)

  17. Real-time optical-fibre luminescence dosimetry for radiotherapy: physical characteristics and applications in photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Aznar, Marianne C [Radiation Research Department, Risoe National Laboratory, Roskilde (Denmark); Andersen, Claus E [Radiation Research Department, Risoe National Laboratory, Roskilde (Denmark); Boetter-Jensen, Lars [Radiation Research Department, Risoe National Laboratory, Roskilde (Denmark); Baeck, Sven A J [Department of Medical Radiation Physics, Lund University, Malmoe University Hospital, Malmoe (Sweden); Mattsson, Soeren [Department of Medical Radiation Physics, Lund University, Malmoe University Hospital, Malmoe (Sweden); Kjaer-Kristoffersen, Flemming [Department of Radiation Physics, Rigshospitalet, National University Hospital, Copenhagen (Denmark); Medin, Joakim [Department of Medical Radiation Physics, Lund University, Malmoe University Hospital, Malmoe (Sweden)

    2004-05-07

    A new optical-fibre radiation dosimeter system, based on radioluminescence and optically stimulated luminescence from carbon-doped aluminium oxide, was developed and tested in clinical photon beams. This prototype offers several features, such as a small detector (1 x 1 x 2 mm{sup 3}), high sensitivity, real-time read-out and the ability to measure both dose rate and absorbed dose. The measurements describing reproducibility and output dependence on dose rate, field size and energy all had standard deviations smaller than 1%. The signal variation with the angle of incidence was smaller than 2% (1 SD). Measurements performed in clinical situations suggest the potential of using this real-time system for in vivo dosimetry in radiotherapy.

  18. Second Vapor-Level Sensor For Vapor Degreaser

    Science.gov (United States)

    Painter, Nance M.; Burley, Richard K.

    1990-01-01

    Second vapor-level sensor installed at lower level in vapor degreaser makes possible to maintain top of vapor at that lower level. Evaporation reduced during idle periods. Provides substantial benefit, without major capital cost of building new vapor degreaser with greater freeboard height.

  19. Literature in Focus Beta Beams: Neutrino Beams

    CERN Document Server

    2009-01-01

    By Mats Lindroos (CERN) and Mauro Mezzetto (INFN Padova, Italy) Imperial Press, 2009 The beta-beam concept for the generation of electron neutrino beams was first proposed by Piero Zucchelli in 2002. The idea created quite a stir, challenging the idea that intense neutrino beams only could be produced from the decay of pions or muons in classical neutrino beams facilities or in future neutrino factories. The concept initially struggled to make an impact but the hard work by many machine physicists, phenomenologists and theoreticians over the last five years has won the beta-beam a well-earned position as one of the frontrunners for a possible future world laboratory for high intensity neutrino oscillation physics. This is the first complete monograph on the beta-beam concept. The book describes both technical aspects and experimental aspects of the beta-beam, providing students and scientists with an insight into the possibilities o...

  20. Raman lidar measurements of tropospheric water vapor over Hefei

    Institute of Scientific and Technical Information of China (English)

    Yonghua Wu(吴永华); Huanling Hu(胡欢陵); Shunxing Hu(胡顺星); Jun Zhou(周军)

    2003-01-01

    L625 Raman lidar has been developed for water vapor measurements over Hefei, China since September2000. By transmitting laser beam of frequency-tripled Nd:YAG laser, Raman scattering signals of watervapor and nitrogen molecules are simultaneously detected by the cooled photomultipliers with photoncounting mode. Water vapor mixing ratios measured by Raman lidar show the good agreements withradiosonde observations, which indicates this Raman lidar is reliable. Many observation cases show thataerosol optical parameters have the good correlation with water vapor distribution in the lower troposphere.

  1. R-22 vapor explosions

    International Nuclear Information System (INIS)

    Previous experimental and theoretical studies of R-22 vapor explosions are reviewed. Results from two experimental investigations of vapor explosions in a medium scale R-22/water system are reported. Measurements following the drop of an unrestrained mass of R-22 into a water tank demonstrated the existence of two types of interaction behavior. Release of a constrained mass of R-22 beneath the surface of a water tank improved the visual resolution of the system thus allowing identification of two interaction mechansims: at low water temperatures, R-22/water contact would produce immediate violent boiling; at high water temperatures a vapor film formed around its R-22 as it was released, explosions were generated by a surface wave which initiated at a single location and propagated along the vapor film as a shock wave. A new vapor explosion model is proposed, it suggests explosions are the result of a sequence of three independent steps: an initial mixing phase, a trigger and growth phase, and a mature phase where a propagating shock wave accelerates the two liquids into a collapsing vapor layer causing a high velocity impact which finely fragments and intermixes the two liquids

  2. The Effect of Nitrogen Gas Flow Rate on the Properties of TiN-COATED High-Speed Steel (hss) Using Cathodic Arc Evaporation Physical Vapor Deposition (pvd) Technique

    Science.gov (United States)

    Mubarak, Ali; Hamzah, Esah Binti; Mohd Toff, Mohd Radzi Hj.; Hashim, Abdul Hakim Bin

    Cathodic arc evaporation (CAE) is a widely-used technique for generating highly ionized plasma from which hard and wear resistant physical vapor deposition (PVD) coatings can be deposited. A major drawback of this technique is the emission of micrometer-sized droplets of cathode material from the arc spot, which are commonly referred to as "macroparticles." In present study, titanium nitride (TiN) coatings on high-speed steel (HSS) coupons were produced with a cathodic arc evaporation technique. We studied and discussed the effect of various nitrogen gas flow rates on microstructural and mechanical properties of TiN-coated HSS coupons. The coating properties investigated in this work included the surface morphology, thickness of deposited coating, adhesion between the coating and substrate, coating composition, coating crystallography, hardness and surface characterization using a field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), X-ray diffraction (XRD) with glazing incidence angle (GIA) technique, scratch tester, hardness testing machine, surface roughness tester, and atomic force microscope (AFM). An increase in the nitrogen gas flow rate showed decrease in the formation of macro-droplets in CAE PVD technique. During XRD-GIA studies, it was observed that by increasing the nitrogen gas flow rate, the main peak [1,1,1] shifted toward the lower angular position. Surface roughness decreased with an increase in nitrogen gas flow rate but was higher than the uncoated polished sample. Microhardness of TiN-coated HSS coupons showed more than two times increase in hardness than the uncoated one. Scratch tester results showed good adhesion between the coating material and substrate. Considerable improvement in the properties of TiN-deposited thin films was achieved by the strict control of all operational steps.

  3. Condensation of water vapor in the gravitational field

    OpenAIRE

    Gorshkov, Victor G.; Makarieva, Anastassia M.; Nefiodov, Andrei V.

    2012-01-01

    Physical peculiarities of water vapor condensation under conditions of hydrostatic equilibrium are considered. The power of stationary dynamic air fluxes and the vertical temperature distribution caused by condensation on large horizontal scales are estimated.

  4. Epitaxy physical principles and technical implementation

    CERN Document Server

    Herman, Marian A; Sitter, Helmut

    2004-01-01

    Epitaxy provides readers with a comprehensive treatment of the modern models and modifications of epitaxy, together with the relevant experimental and technological framework. This advanced textbook describes all important aspects of the epitaxial growth processes of solid films on crystalline substrates, including a section on heteroepitaxy. It covers and discusses in details the most important epitaxial growth techniques, which are currently widely used in basic research as well as in manufacturing processes of devices, namely solid-phase epitaxy, liquid-phase epitaxy, vapor-phase epitaxy, including metal-organic vapor-phase epitaxy and molecular-beam epitaxy. Epitaxy’s coverage of science and texhnology thin-film is intended to fill the need for a comprehensive reference and text examining the variety of problems related to the physical foundations and technical implementation of epitaxial crystallization. It is intended for undergraduate students, PhD students, research scientists, lecturers and practic...

  5. Characterization of electron-beam-modified surface coated clay fillers and their influence on physical properties of rubbers

    International Nuclear Information System (INIS)

    A novel process of surface modification of clay filler has been developed by coating this with an acrylate monomer, trimethylol propane triacrylate (TMPTA) or a silane coupling agent, triethoxy vinyl silane (TEVS) followed by electron beam irradiation. Characterization of these surface modified fillers has been carried out by Fourier-transform infrared analysis (FTIR), electron spectroscopy for chemical analysis (ESCA), wettability by dynamic wicking method measuring the rise of a liquid through a filler-packed capillary tube and water flotation test, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Presence of the acrylate and the silane coupling agent on the modified fillers has been confirmed from FTIR, ESCA, and EDX studies, which has also been supported by TGA studies. The contact angle measurement by dynamic wicking method suggests improvement in hydrophobicity of the treated fillers, which is supported by water flotation test especially in the case of silanized clay. However, XRD studies demonstrate that the entire modification process does not affect the bulk properties of the fillers. Finally, both unmodified and modified clay fillers have been incorporated in styrene butadiene rubber (SBR) and nitrile rubber (NBR). Rheometric and mechanical properties reveal that there is a definite improvement using these modified fillers specially in the case of silanized clay compared to the control sample, probably due to successful enhancement in interaction between the treated clay and the base polymer

  6. Physical meaning of supersonic molecular beams; Fondamenti fisici dei fasci molecolari supersonici : parte terza : flusso isoentropico; linee caratteristiche

    Energy Technology Data Exchange (ETDEWEB)

    Tomassetti, G. [L`Aquila Univ. (Italy). Dip. di Fisica; Sanna, G.

    1996-11-01

    In this report a generic steady isentropic flow is firstly considered and the flow variables are expressed as functions of the Mach number and of the stagnation parameters. Then, the physical meaning of the characteristic lines is pointed out and the compression, shock and expansion waves are analysed in terms of such lines. The concept of characteristic is also introduced from a purely mathematical point of view. Furthermore, the cases of a uniform planar flow with a small perturbation and of a planar flow near curved walls are analysed.

  7. Space charge dominated beams

    International Nuclear Information System (INIS)

    After an introductory section on the relationship between emittance and beam Coulomb energy we discuss the properties of space charge dominated beams in progressive steps: from uniformly charged bunched beams to non-uniformly charged beams to correlation effects between particles (simulation beams or 'crystalline' beams). A practical application can be found in the beam dynamics of a high-current injector. The concept of correlation energy is of practical interest in computer simulation of high-brilliance beams, where one deals with an artificially enhanced two-particle Coulomb energy, if many real particles are combined into one simulation super-particle. This can be a source of non-physical emittance growth. (orig./HSI)

  8. Visible laser discharge studies. Quarterly progress report, June 1, 1977--August 31, 1977. [CdHg vapors

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, B N; Jacob, J H; Mangano, J A

    1977-01-01

    In order to facilitate the development of metal vapor excimer lasers for inertial fusion, a theoretical study has been undertaken to identify the dominant discharge physics and kinetics for metal vapor excimers like cadmium-mercury (CdHg). Interest in such lasers have been heightened since the reported observation of gain in CdHg. An efficient method of pumping the first excited state of metal vapors is by secondary electrons created in a discharge. By discharge pumping it is possible to create mainly the lowest excited state, thereby minimizing highly excited electronic states that could photoabsorb. E-beam pumping may have difficulty in pumping metal vapor excimers due to photoabsorption by excited species. To obtain high efficiencies for CdHg system by discharge pumping three technical issues must be addressed: (1) inefficiencies in discharge pumping due to energy flow into excited states; (2) discharge stability; and (3) efficient discharge enhancement. The present effort is directed to the above issues through the development of a kinetics code that models the dominant kinetics of CdHg laser system. The bulk of the report is devoted to identification of inefficiencies in discharge pumping due to energy flow into excited states. The analysis can also be used to predict discharge stability and discharge enhancement.

  9. Vapor pressures and enthalpies of vaporization of azides

    Energy Technology Data Exchange (ETDEWEB)

    Verevkin, Sergey P., E-mail: sergey.verevkin@uni-rostock.de [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059 Rostock (Germany); Emel' yanenko, Vladimir N. [Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059 Rostock (Germany); Algarra, Manuel [Centro de Geologia do Porto, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Manuel Lopez-Romero, J. [Department of Organic Chemistry, University of Malaga. Campus de Teatinos s/n, 29071 Malaga (Spain); Aguiar, Fabio; Enrique Rodriguez-Borges, J.; Esteves da Silva, Joaquim C.G. [Centro de Investigacao em Quimica (CIQ-UP), Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2011-11-15

    Highlights: > We prepared and measured vapor pressures and vaporization enthalpies of 7 azides. > We examined consistency of new and available in the literature data. > Data for geminal azides and azido-alkanes selected for thermochemical calculations. - Abstract: Vapor pressures of some azides have been determined by the transpiration method. The molar enthalpies of vaporization {Delta}{sub l}{sup g}H{sub m} of these compounds were derived from the temperature dependencies of vapor pressures. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of similarly structured compounds.

  10. Phase evolution, interdiffusion and failure of La2(Zr0.7Ce0.3)2O7/YSZ thermal barrier coatings prepared by electron beam–physical vapor deposition

    International Nuclear Information System (INIS)

    Highlights: • No interruption of column morphology from YSZ to LZ7C3 layer in TBCs. • A fluorite to pyrochlore ordering occurs for LZ7C3 during thermal shocking. • Some diffusion of Y from YSZ to LZ7C3 layer is occurred after thermal shocking. • Outward diffusion of Cr takes place due to the chemical reaction of LZ7C3 and Cr. • The delaminations occur at interface of LZ7C3/YSZ and inside the LZ7C3 coating. - Abstract: La2(Zr0.7Ce0.3)2O7 (LZ7C3) has attracted great interest for thermal barrier coatings (TBCs) because it presents extremely low thermal conductivity, high thermal stability and is more resistant to sintering than yttria stabilized zirconia (YSZ). In the present study, an LZ7C3/YSZ double-ceramic-layer (DCL) TBC was deposited by electron beam–physical vapor deposition (EB–PVD) and the TBC system was investigated for its phase evolution, interdiffusion and failure pattern though thermal shock test at 1373 K. X-ray diffraction and Raman spectra results indicate that the as-deposited LZ7C3 coating transforms from fluorite to pyrochlore structure upon thermal shocking between 373 K and 1373 K. It seems that this phase change may have affected the durability of the DCL TBCs. The EDS mapping analysis indicates that some diffusion of Y from YSZ to LZ7C3 layer is occurred after thermal shock test. Additionally, an obvious outward diffusion of Cr from bond coat into LZ7C3 layer takes place due to the chemical reaction of LZ7C3 and Cr. The phase transformation of LZ7C3, the abnormal oxidation of bond coat, and the outward diffusion of Y and Cr alloying element into LZ7C3 coating would be the primary factors for the spallation of LZ7C3/YSZ thermal barrier coating

  11. Cross sections of electron loss and capture for beams of O{sup +} in water vapor from the energy range of 0,2 to 1,2 MeV; Secoes de choque de perda e captura eletronica para feixes de O{sup +} em vapor de agua em uma faixa de energia entre 0,2 e 1,2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Vitor Jesus de

    2015-06-01

    The study of the interactions between atoms and molecules is important for the knowledge of the cross sections of the processes that contribute to the deposition of energy by charged particle beams used in radiotherapy planning and transport particle simulation codes. Heavy ions, such as oxygen, induce many cellular and molecular damages in human cells.as a result of interaction between the projectile and atoms and molecules. The use of proton and carbon as the projectile interacting with water molecules is well characterized, however there are few studies with oxygen ions. In this work we are interested in the study of electron loss (projectile ionization) and electron capture with charge state 1+. The Pelletron accelerator of 1.7 MeV from the Federal University of Rio de Janeiro housed in the Atomic and Molecular collisions Laboratory (LACAM) has been used, which can accelerate atomic and molecular ions up to speeds of the order of hundredths of light speed, and consists of the source of negative ions, the Wien filter, the accelerator itself and the magnet load selector. The detection device used to evaluate the processes of interaction (capture and loss) between the beam of the O{sup +} and the water molecule is a Microchannel Plate (MCP) at the position sensitive anode. The collisions of O{sup +} beans are being studied in the range of 0.2 to 1.2 MeV with water vapor (Z = 10). Were obtained the respective absolute cross sections for electron loss and electron capture and compared with the cross sections of the molecule methane (CH4 → Z = 10), the isoelectronic water molecule. The experimental results show an agreement between the measurements with water and methane. Comparisons were made with results of theoretical models for electron loss using the 'Free Collision Model' and for capture the Bohr and Lindhard model. The theoretical results for electron loss show an agreement of experimental data with the model used. The model of Bohr and Lindhard

  12. Beam-beam studies for the High-Energy LHC

    CERN Document Server

    Ohmi, K; Zimmermann, F

    2011-01-01

    LHC upgrades are being considered both towards higher luminosity (HL-LHC) and towards higher energy (HE-LHC). In this paper we report initial studies of the beam-beam effects in the HE-LHC [1]. The HE-LHC aims at beam energies of 16.5 TeV, where the transverse emittance decreases due to synchrotron radiation with a 2-hour damping time. As a result of this emittance, shrinkage the beam-beam parameter increases with time, during a physics store. The beam-beam limit in the HE-LHC is explored using computer simulations.

  13. Soil vapor extraction with dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, N.R. [Univ. of Waterloo, Ontario (Canada)

    1996-08-01

    The physical treatment technology of soil vapor extraction (SVE) is reliable, safe, robust, and able to remove significant amounts of mass at a relatively low cost. SVE combined with a pump-and-treat system to create a dewatered zone has the opportunity to remove more mass with the added cost of treating the extracted groundwater. Various limiting processes result in a significant reduction in the overall mass removal rates from a SVE system in porous media. Only pilot scale, limited duration SVE tests conducted in low permeability media have been reported in the literature. It is expected that the presence of a fracture network in low permeability media will add another complexity to the limiting conditions surrounding the SVE technology. 20 refs., 4 figs.

  14. Prediction of electron beam welding spiking tendency

    International Nuclear Information System (INIS)

    On the basis of measured temperature distributions in electron beam welding cavities it is shown that the vapor pressure force dominates in the lower region and the surface tension in the upper region. The region where these two forces are approximately equal is unstable and the surface tension force causes inward flow of liquid metal which tends to form a projection. For a specific material this projection location was found to depend on cavity depth. By postulating that the formation of liquid metal projections at this location results in cavity instabilities, a physical model for predicting when spiking would occur was purposed. A procedure then developed for determining the spiking tendency for a specified material and set of weld parameters is described

  15. Passive Vaporizing Heat Sink

    Science.gov (United States)

    Knowles, TImothy R.; Ashford, Victor A.; Carpenter, Michael G.; Bier, Thomas M.

    2011-01-01

    A passive vaporizing heat sink has been developed as a relatively lightweight, compact alternative to related prior heat sinks based, variously, on evaporation of sprayed liquids or on sublimation of solids. This heat sink is designed for short-term dissipation of a large amount of heat and was originally intended for use in regulating the temperature of spacecraft equipment during launch or re-entry. It could also be useful in a terrestrial setting in which there is a requirement for a lightweight, compact means of short-term cooling. This heat sink includes a hermetic package closed with a pressure-relief valve and containing an expendable and rechargeable coolant liquid (e.g., water) and a conductive carbon-fiber wick. The vapor of the liquid escapes when the temperature exceeds the boiling point corresponding to the vapor pressure determined by the setting of the pressure-relief valve. The great advantage of this heat sink over a melting-paraffin or similar phase-change heat sink of equal capacity is that by virtue of the =10x greater latent heat of vaporization, a coolant-liquid volume equal to =1/10 of the paraffin volume can suffice.

  16. Vapor liquid fraction determination

    International Nuclear Information System (INIS)

    This invention describes a method of measuring liquid and vapor fractions in a non-homogeneous fluid flowing through an elongate conduit, such as may be required with boiling water, non-boiling turbulent flows, fluidized bed experiments, water-gas mixing analysis, and nuclear plant cooling. (UK)

  17. A large liquid argon time projection chamber for long-baseline, off-axis neutrino oscillation physics with the NuMI beam

    International Nuclear Information System (INIS)

    Results from neutrino oscillation experiments in the last ten years have revolutionized the field of neutrino physics. While the overall oscillation picture for three neutrinos is now well established and precision measurements of the oscillation parameters are underway, crucial issues remain. In particular, the hierarchy of the neutrino masses, the structure of the neutrino mixing matrix, and, above all, CP violation in the neutrino sector are the primary experimental challenges in upcoming years. A program that utilizes the newly commissioned NuMI neutrino beamline, and its planned upgrades, together with a high-performance, large-mass detector will be in an excellent position to provide decisive answers to these key neutrino physics questions. A Liquid Argon time projection chamber (LArTPC), which combines fine-grained tracking, total absorption calorimetry, and scalability, is well matched for this physics program. The few-millimeter-scale spatial granularity of a LArTPC combined with dE/dx measurements make it a powerful detector for neutrino oscillation physics. Scans of simulated event samples, both directed and blind, have shown that electron identification in νe charged current interactions can be maintained at an efficiency of 80%. Backgrounds for νe appearance searches from neutral current events with a π0 are reduced well below the ∼ 0.5-1.0% νe contamination of the νμ beam. While the ICARUS collaboration has pioneered this technology and shown its feasibility with successful operation of the T600 (600-ton) LArTPC, a detector for off-axis, long-baseline neutrino physics must be many times more massive to compensate for the low event rates. We have a baseline concept based on the ICARUS wire plane structure and commercial methods of argon purification and housed in an industrial liquefied-natural-gas tank. Fifteen to fifty kton liquid argon capacity tanks have been considered. A very preliminary cost estimate for a 50-kton detector is $100M

  18. Muonium formation in vapors

    International Nuclear Information System (INIS)

    The fractions of positive muons thermalizing in vapors as either the muonium atom (fsub(M)) or in diamagnetic environments (fsub(D)) have been measured in water, methanol, hexane, c-hexane, the chlorinated methanes and in TMS, in the pressure range from approximately 0.1 to approximately 2.5 atm. There is a marked difference in every case in comparison with the corresponding fractions (Psub(M),Psub(D)) measured in condensed media, with approximately 80 percent of incident muons forming muonium in the vapor phase compared to approximately 20 percent in the corresponding condensed phases. CClsub(4) appears somewhat anomalous in that it shows an unusually small muonium fraction in the vapor (fsub(D) approximately fsub(M)=0.5) and an unusually large diamagnetic fraction in the liquid (Psub(D)=1.0); these results can be attributed to large hot atom cross sections extending to the thermal regime, manifest as a relatively fast thermal rate constant for Mu + CClsub(4) (ksub(MU)=(2.9+-0.8) x 10sup(8) Msup(-1) ssup(-1)). The vapor phase results can be understood in terms of a charge exchange/hot atom (ion) model, providing also a likely explanation for observed pressure dependent fsub(D)'s in hexane, c-hexane and TMS at low (<0.5 atm) pressures in terms of termolecular processes, in analogy with some hot tritium studies. In the condensed phase, however, the present vapor phase results indicate that hot atom reactions cannot account for more than about 30 percent of the much larger diamagnetic fractions seen, strongly suggesting therefore that radiation induced spur effects play a dominant role in determining thermal muon fractions in condensed media

  19. Application of instruments of nuclear physics to the calculation of theoretical dose distributions in various organs of the human body for beams used in hadrontherapy

    Directory of Open Access Journals (Sweden)

    Maliszewska Weronika

    2016-03-01

    Full Text Available The area of interests of nuclear physics are studies of reactions, wherein atomic nuclei of projectile collide with target nuclei. An amount of energy lost by projectile nucleus during its passing through the target is a major issue – it is important to know how charged particles interact with matter. It is possible to afford this knowledge by using theoretical programs that calculate energy loss applying the Bethe-Bloch equation. Hadrontherapy, which is a field of still growing interest, is based on the interactions of charged particles with matter. Therefore, there exists a need of creating a simple model that could be used to the calculation of dose distributions in biological matter. Two programs (SRIM, Xeloss, used to the calculation of energy loss by nuclear physicist, have been adapted to determine the dose distributions in analogues of human tissues. Results of the calculations with those programs for beams used in hadrontherapy (e.g. 1H, 12C will be compared with experimental data available in references.

  20. Characterisation of Pristine and Recoated electron beam evaporation plasma-assisted physical vapour deposition Cr-N coatings on AISI M2 steel and WC-Co substrates

    International Nuclear Information System (INIS)

    This paper is focussed on the characterisation of electron beam evaporation plasma-assisted physical vapour deposition Cr-N coatings deposited on AISI M2 steel and hardmetal (K10) substrates in two different conditions: Pristine (i.e., coated) and Recoated (i.e., stripped and recoated). Analytical methods, including X-ray diffraction (XRD), scanning electron microscopy, scratch adhesion and pin-on-disc tests were used to evaluate several coating properties. XRD analyses indicated that both Pristine and Recoated coatings consisted of a mixture of hexagonal Cr2N and cubic CrN, regardless of substrate type. For the M2 steel substrate, only small differences were found in terms of coating phases, microstructure, adhesion, friction and wear coefficients between Pristine and Recoated. Recoated on WC-Co (K10) exhibited a less dense microstructure and significant inferior adhesion compared to Pristine on WC-Co (K10). The wear coefficient of Recoated on WC-Co was 100 times higher than those exhibited by all other specimens. The results obtained confirm that the stripping process did not adversely affect the Cr-N properties when this coating was deposited onto M2 steel substrates, but it is clear from the unsatisfactory tribological performance of Recoated on WC-Co that the stripping process is unsuitable for hardmetal substrates

  1. Stratified vapor generator

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, Desikan (Lakewood, CO); Hassani, Vahab (Golden, CO)

    2008-05-20

    A stratified vapor generator (110) comprises a first heating section (H.sub.1) and a second heating section (H.sub.2). The first and second heating sections (H.sub.1, H.sub.2) are arranged so that the inlet of the second heating section (H.sub.2) is operatively associated with the outlet of the first heating section (H.sub.1). A moisture separator (126) having a vapor outlet (164) and a liquid outlet (144) is operatively associated with the outlet (124) of the second heating section (H.sub.2). A cooling section (C.sub.1) is operatively associated with the liquid outlet (144) of the moisture separator (126) and includes an outlet that is operatively associated with the inlet of the second heating section (H.sub.2).

  2. Fluid metals the liquid-vapor transition of metals

    CERN Document Server

    Hensel, Friedrich

    2014-01-01

    This is a long-needed general introduction to the physics and chemistry of the liquid-vapor phase transition of metals. Physicists and physical chemists have made great strides understanding the basic principles involved, and engineers have discovered a wide variety of new uses for fluid metals. Yet there has been no book that brings together the latest ideas and findings in the field or that bridges the conceptual gap between the condensed-matter physics relevant to a dense metallic liquid and the molecular chemistry relevant to a dilute atomic vapor. Friedrich Hensel and William Warren seek

  3. Gasoline vapor biofiltration

    Energy Technology Data Exchange (ETDEWEB)

    Paca, J.; Halecky, M. [Institute of Chemical Technology, Department of Fermentation Chemistry and Bioengineering, Prague (Czech Republic); Maryska, M. [Institute of Chemical Technology, Department of Glass and Ceramics, Prague (Czech Republic); Jones, K. [South Texas Environmental Institute, Texas A and M University-Kingsville, Kingsville (United States)

    2007-10-15

    While gasoline vapor emissions are common sources of air pollution, very few results have been published on the biofilter biodegradation of gasoline vapors in flowing waste gases. This investigation reports on a bench-scale biofilter of an ID of 50 mm and a bed height of 850 mm with an inexpensive fire clay chip medium as a packing material. The biofilter was inoculated with a concentrate of a mixed culture of the common microflora. After an acclimatization period of three weeks, loading tests were carried out at increasing gasoline inlet concentrations at a constant Empty Bed Retention Time (EBRT) of 16 min. Evaluating the removal rate and efficiency of aliphatic and aromatic fractions of the gasoline vapor, it was found that in a range of overall organic loading (OL{sub TPH}) up to 33.6 g/m{sup 3} h the removal efficiency of aromatic hydrocarbons decreased from 90 to 70 %, while that of the aliphatic components decreased much more significantly from 60 to 10 % after six months of operation. The removal rate and efficiency achieved for total petroleum hydrocarbons were 13 g/m{sup 3} h and 45 %, respectively. The microbial strains and genera of culturable cells in the inoculum and in the biofilm after six months of gasoline degradation were evaluated. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  4. Molecular physics

    CERN Document Server

    Williams, Dudley

    2013-01-01

    Methods of Experimental Physics, Volume 3: Molecular Physics focuses on molecular theory, spectroscopy, resonance, molecular beams, and electric and thermodynamic properties. The manuscript first considers the origins of molecular theory, molecular physics, and molecular spectroscopy, as well as microwave spectroscopy, electronic spectra, and Raman effect. The text then ponders on diffraction methods of molecular structure determination and resonance studies. Topics include techniques of electron, neutron, and x-ray diffraction and nuclear magnetic, nuclear quadropole, and electron spin reson

  5. Effects of E-Beam Irradiation on the Chemical, Physical, and Electrochemical Properties of Activated Carbons for Electric Double-Layer Capacitors

    OpenAIRE

    Min-Jung Jung; Mi-Seon Park; Young-Seak Lee

    2015-01-01

    Activated carbons (ACs) were modified via e-beam irradiation at various doses for use as an electrode material in electric double-layer capacitors (EDLCs). The chemical compositions of the AC surfaces were largely unchanged by the e-beam irradiation. The ACs treated with the e-beam at radiation doses of 200 kGy exhibited higher nanocrystallinity than the untreated ACs. The specific surface areas and pore volumes of the e-beam irradiated ACs were also higher than those of the untreated ACs. Th...

  6. Effects of vertical distribution of water vapor and temperature on total column water vapor retrieval error

    Science.gov (United States)

    Sun, Jielun

    1993-01-01

    Results are presented of a test of the physically based total column water vapor retrieval algorithm of Wentz (1992) for sensitivity to realistic vertical distributions of temperature and water vapor. The ECMWF monthly averaged temperature and humidity fields are used to simulate the spatial pattern of systematic retrieval error of total column water vapor due to this sensitivity. The estimated systematic error is within 0.1 g/sq cm over about 70 percent of the global ocean area; systematic errors greater than 0.3 g/sq cm are expected to exist only over a few well-defined regions, about 3 percent of the global oceans, assuming that the global mean value is unbiased.

  7. Cost-effective mechanical vapor recompression

    International Nuclear Information System (INIS)

    Explains how increasing natural gas costs provided the incentive to install a mechanical vapor recompression unit that accomodates variations in production rates and provides for plant expansion. The evaporator can concentrate uranyl nitrate solution with much more energy efficiency. Uranyl nitrate solution is purified in the solvent extraction portion of the process, concentrated by evaporation, and then introduced into boildown, where all remaining free water is removed. Benefits of a vapor recompression evaporation system over a single-effect evaporator include not only energy cost savings, but a reduction of about 50% on the plant steam demand and 35% on the heat and pumping load of the plant cooling tower. Material to be evaporated must be thoroughly evaluated to determine that the physical properties are within the economic limits of a vapor recompression system. Available energy sources and other plant needs must also be considered. Concludes that comparison of the installed and operating costs reveals that the multi-effect system cannot compete economically with mechanical vapor recompression, unless the former can also meet unique thermal needs of the plant other than evaporation

  8. Vaporization of synthetic fuels. Final report. [Thesis

    Energy Technology Data Exchange (ETDEWEB)

    Sirignano, W.A.; Yao, S.C.; Tong, A.Y.; Talley, D.

    1983-01-01

    The problem of transient droplet vaporization in a hot convective environment is examined. The main objective of the present study is to develop an algorithm for the droplet vaporization which is simple enough to be feasibly incorporated into a complete spray combustion analysis and yet will also account for the important physics such as liquid-phase internal circulation, unsteady droplet heating and axisymmetric gas-phase convection. A simplified liquid-phase model has been obtained based on the assumption of the existence of a Hill's spherical vortex inside the droplet together with some approximations made in the governing diffusion equation. The use of the simplified model in a spray situation has also been examined. It has been found that droplet heating and vaporization are essentially unsteady and droplet temperature is nonuniform for a significant portion of its lifetime. It has also been found that the droplet vaporization characteristic can be quite sensitive to the particular liquid-phase and gas-phase models. The results of the various models are compared with the existing experimental data. Due to large scattering in the experimental measurements, particularly the droplet diameter, no definite conclusion can be drawn based on the experimental data. Finally, certain research problems which are related to the present study are suggested for future studies.

  9. Nonlinear beam-beam resonances

    International Nuclear Information System (INIS)

    Head-on collisions of bunched beams are considered, assuming the two colliding beams have opposite charges. A few experimental observations are described. The single resonance analysis is developed that is applicable to the strong-weak case of the beam-beam interaction. In this case, the strong beam is unperturbed by the beam-beam interaction; motions of the weak beam particles are then analyzed in the presence of the nonlinear electromagnetic force produced by the strong beam at the collision points. The coherent motions of the two coupled strong beams are shown to exhibit distinct nonlinear resonance behavior. 16 refs., 22 figs

  10. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    Energy Technology Data Exchange (ETDEWEB)

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  11. Effects of E-Beam Irradiation on the Chemical, Physical, and Electrochemical Properties of Activated Carbons for Electric Double-Layer Capacitors

    Directory of Open Access Journals (Sweden)

    Min-Jung Jung

    2015-01-01

    Full Text Available Activated carbons (ACs were modified via e-beam irradiation at various doses for use as an electrode material in electric double-layer capacitors (EDLCs. The chemical compositions of the AC surfaces were largely unchanged by the e-beam irradiation. The ACs treated with the e-beam at radiation doses of 200 kGy exhibited higher nanocrystallinity than the untreated ACs. The specific surface areas and pore volumes of the e-beam irradiated ACs were also higher than those of the untreated ACs. These results were attributed to the transformation and degradation of the nanocrystallinity of the AC surfaces due to the e-beam irradiation. The specific capacitance of the ACs treated with the e-beam at radiation doses of 200 kGy increased by 24% compared with the untreated ACs, and the charge transfer resistance of the ACs was decreased by the e-beam irradiation. The enhancement of the electrochemical properties of the e-beam irradiated ACs can be attributed to an increase in their specific surface area and surface crystallinity.

  12. Intense electron and ion beams

    CERN Document Server

    Molokovsky, Sergey Ivanovich

    2005-01-01

    Intense Ion and Electron Beams treats intense charged-particle beams used in vacuum tubes, particle beam technology and experimental installations such as free electron lasers and accelerators. It addresses, among other things, the physics and basic theory of intense charged-particle beams; computation and design of charged-particle guns and focusing systems; multiple-beam charged-particle systems; and experimental methods for investigating intense particle beams. The coverage is carefully balanced between the physics of intense charged-particle beams and the design of optical systems for their formation and focusing. It can be recommended to all scientists studying or applying vacuum electronics and charged-particle beam technology, including students, engineers and researchers.

  13. X-ray fluorescence in Member States: Greece. Ion micro-beam analysis and XRF related activities at the Institute of Nuclear Physics, NCSR 'Demokritos', Greece (2007-2008)

    International Nuclear Information System (INIS)

    The activities of the Institute of Nuclear Physics in the field of Ion-Beam and XRF analytical techniques during 2007-2008 included research and development projects together with training and dissemination activities, in particular concerning the implementation of nuclear analytical techniques in the field of cultural heritage. The following activities are described in more detail: Development of the 3D-MicroPIXE technique; Development of an external Ion-Beam set-up at the Tandem accelerator of the Institute of Nuclear Physics; Development of an integrated PIXE-XRF technique; Development and validation of a quantification methodology for a portable micro-XRF spectrometer; The PROMET analytical campaign in the Syrian Arab Republic and Jordan, Oct/Nov 2007

  14. Electron-beam diagnostic for space-charge measurement of an ion beam

    OpenAIRE

    Roy, Prabir K.; Yu, Simon S.; Henestroza, Enrique; Eylon, Shmuel; Shuman, Derek B.; Ludvig, Jozsef; Bieniosek, Frank M.; Waldron, William L.; Greenway, Wayne G.; Vanecek, David L.; Hannink, Ryan; Amezcua, Monserrat

    2003-01-01

    An electron beam diagnostic system for measuring the charge distribution of an ion beam without changing its properties is presently under development for Heavy Ion Fusion (HIF) beam physics studies. Conventional diagnostics require temporary insertion of sensors into the beam, but these capture it, or significantly alter its properties. In this new diagnostic a low energy, low current electron beam is scanned transversely across the ion beam; the measured electron beam deflection is use...

  15. WOOD VAPORIZATION EFFECT ON SOME MECHANICAL PROPERTIES OF Eucalyptus dunnii

    Directory of Open Access Journals (Sweden)

    Clóvis Roberto Haselein

    2009-10-01

    Full Text Available The aim of this study was to evaluate the vaporization effects on the crushing strength at limit of proportionality on perpendicular compression, crushing strength and modulus of elasticity in parallel compression to the fiber and shear strength (radial and tangential direction on logs and sawn wood of two sources of Eucalyptus dunnii. The mechanical attempts were performed under the Copant standards in the  climatized conditions (12%. To do so, about two thirds of the logs, with a diameter between 20-30 cm, were vaporized at 100o C and 100% of relative humidity for 20 hours, while  the  remaining  logs  were  kept  as  control.  From  each  log,  a  central plank radially directed with eight centimeter of thickness was taken, from which small beams of 8 cm x 8 cm were taken. Half of the small beams from the vaporized logs were once again submitted to vaporization under the same previously described conditions for a period of 3 hours, thus obtaining three different levels of comparison (control, vaporized on logs and presteaming wood. The results showed a remarkable reduction on the crushing strength in parallel compression to the fiber and shear strength (radial and tangential direction with the vaporization on the two conditions and sources of Eucalyptus dunnii used. On the other hand, the crushing strength at limit of proportionality on perpendicular compression and modulus of elasticity in parallel compression did not show any change with the vaporization.

  16. Tractor beams for optical micromanipulation

    Science.gov (United States)

    Yevick, Aaron; Grier, David G.

    2016-03-01

    Tractor beams are traveling waves that transport illuminated objects in the retrograde direction relative to the direction of propagation. The theory of photokinetic effects identifies design criteria for long-range general- purpose tractor beams. These criteria distinguish first-order tractor beams that couple to induced dipole moments from higher-order tractor beams that rely on coupling to higher-order multipole moments to achieve pulling. First-order tractor beams are inherently longer-ranged and operate on a wider variety of materials. We explore the physics of first-order tractor beams in the context of a family of generalized solenoidal waves.

  17. Strong Metal-Support Interaction: Growth of Individual Carbon Nanofibers from Amorphous Carbon Interacting with an Electron Beam

    DEFF Research Database (Denmark)

    Zhang, Wei; Kuhn, Luise Theil

    2013-01-01

    The article discusses the growth behavior of carbon nanofibers (CNFs). It mentions that CNFs can be synthesized using methods such as arc-discharge, laser ablation and chemical vapor deposition. It further states that CNFs can be grown from a physical mixing of amorphous carbon and CGO/Ni nanopar......The article discusses the growth behavior of carbon nanofibers (CNFs). It mentions that CNFs can be synthesized using methods such as arc-discharge, laser ablation and chemical vapor deposition. It further states that CNFs can be grown from a physical mixing of amorphous carbon and CGO....../Ni nanoparticles, devoid of any gaseous carbon source and external heating and stimulated by an electron beam in a 300 kilo volt transmission electron microscope....

  18. Bionanomaterials and Bioinspired Nanostructures for Selective Vapor Sensing

    Science.gov (United States)

    Potyrailo, Radislav; Naik, Rajesh R.

    2013-07-01

    At present, monitoring of air at the workplace, in urban environments, and on battlefields; exhaled air from medical patients; air in packaged food containers; and so forth can be accomplished with different types of analytical instruments. Vapor sensors have their niche in these measurements when an unobtrusive, low-power, and cost-sensitive technical solution is required. Unfortunately, existing vapor sensors often degrade their vapor-quantitation accuracy in the presence of high levels of interferences and cannot quantitate several components in complex gas mixtures. Thus, new sensing approaches with improved sensor selectivity are required. This technological task can be accomplished by the careful design of sensing materials with new performance properties and by coupling these materials with the suitable physical transducers. This review is focused on the assessment of the capabilities of bionanomaterials and bioinspired nanostructures for selective vapor sensing. We demonstrate that these sensing materials can operate with diverse transducers based on electrical, mechanical, and optical readout principles and can provide vapor-response selectivity previously unattainable by using other sensing materials. This ability for selective vapor sensing provides opportunities to significantly impact the major directions in development and application scenarios of vapor sensors.

  19. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  20. Prize for Industrial Applications of Physics Talk: Low energy spread Ion source for focused ion beam systems-Search for the holy grail

    Science.gov (United States)

    Ward, Bill

    2011-03-01

    In this talk I will cover my personal experiences as a serial entrepreneur and founder of a succession of focused ion beam companies (1). Ion Beam Technology, which developed a 200kv (FIB) direct ion implanter (2). Micrion, where the FIB found a market in circuit edit and mask repair, which eventually merged with FEI corporation. and (3). ALIS Corporation which develop the Orion system, the first commercially successful sub-nanometer helium ion microscope, that was ultimately acquired by Carl Zeiss corporation. I will share this adventure beginning with my experiences in the early days of ion beam implantation and e-beam lithography which lead up to the final breakthrough understanding of the mechanisms that govern the successful creation and operation of a single atom ion source.