Improvement of sensitivity in high-resolution Rutherford backscattering spectroscopy

International Nuclear Information System (INIS)

Hashimoto, H.; Nakajima, K.; Suzuki, M.; Kimura, K.; Sasakawa, K.

2011-01-01

The sensitivity (limit of detection) of high-resolution Rutherford backscattering spectroscopy (HRBS) is mainly determined by the background noise of the spectrometer. There are two major origins of the background noise in HRBS, one is the stray ions scattered from the inner wall of the vacuum chamber of the spectrometer and the other is the dark noise of the microchannel plate (MCP) detector which is commonly used as a focal plane detector of the spectrometer in HRBS. In order to reject the stray ions, several barriers are installed inside the spectrometer and a thin Mylar foil is mounted in front of the detector. The dark noise of the MCP detector is rejected by the coincidence measurement with the secondary electrons emitted from the Mylar foil upon the ion passage. After these improvements, the background noise is reduced by a factor of 200 at a maximum. The detection limit can be improved down to 10 ppm for As in Si at a measurement time of 1 h under ideal conditions.

Application of Rutherford backscattering and nuclear reaction analysis techniques for investigation of thin films

International Nuclear Information System (INIS)

Kiss, A.Z.; Simon, A.; Elekes, Z.; Ditroi, F.; Meszaros, S.; Beke, D.L.; Langer, G.A.; Daroczy, L.

2002-01-01

A study of the intermixing of the elements in amorphous Si-Ge multilayers have been carried out using Rutherford backscattering Spectrometry (RBS) technique. Interdiffusion coefficient was determined by measuring the intensity of the first Ge peak (having best depth resolution) in the RBS spectrum as a function of annealing time. The oxygen content of the multilayer was measured by the resonance elastic scattering method in co-operation with Dubna. A cross comparison of multilayered films were performed between the laboratories in Debrecen, Dubna, Albany and Dhaka. An essay to determine the nitrogen content of CVD diamond by the deuteron induced gamma ray emission method has been done. (author)

Study of cerium diffusion in undoped lithium-6 enriched glass with Rutherford backscattering spectrometry

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiaodong, E-mail: xzhang39@utk.edu [Department of Nuclear Engineering, University of Tennessee, TN 37996 (United States); Moore, Michael E.; Lee, Kyung-Min; Lukosi, Eric D. [Department of Nuclear Engineering, University of Tennessee, TN 37996 (United States); Hayward, Jason P. [Department of Nuclear Engineering, University of Tennessee, TN 37996 (United States); Oak Ridge National Lab, Oak Ridge, TN 37831 (United States)

2016-07-01

Undoped lithium-6 enriched glasses coated with pure cerium (99.9%) with a gold protection layer on top were heated at three different temperatures (500, 550, and 600 °C) for varied durations (1, 2, and 4 h). Diffusion profiles of cerium in such glasses were obtained with the conventional Rutherford backscattering technique. Through fitting the diffusion profiles with the thin-film solution of Fick’s second law, diffusion coefficients of cerium with different annealing temperatures and durations were solved. Then, the activation energy of cerium for the diffusion process in the studied glasses was found to be 114 kJ/mol with the Arrhenius equation.

Study of cerium diffusion in undoped lithium-6 enriched glass with Rutherford backscattering spectrometry

Science.gov (United States)

Zhang, Xiaodong; Moore, Michael E.; Lee, Kyung-Min; Lukosi, Eric D.; Hayward, Jason P.

2016-07-01

Undoped lithium-6 enriched glasses coated with pure cerium (99.9%) with a gold protection layer on top were heated at three different temperatures (500, 550, and 600 °C) for varied durations (1, 2, and 4 h). Diffusion profiles of cerium in such glasses were obtained with the conventional Rutherford backscattering technique. Through fitting the diffusion profiles with the thin-film solution of Fick's second law, diffusion coefficients of cerium with different annealing temperatures and durations were solved. Then, the activation energy of cerium for the diffusion process in the studied glasses was found to be 114 kJ/mol with the Arrhenius equation.

Search for an anomalous near-surface yield deficit in Rutherford backscattering spectra from implanted germanium and silicon

International Nuclear Information System (INIS)

Lawson, E.M.; Appleton, B.R.

1983-09-01

Rutherford backscattering and channelling analysis of high-dose, room-temperature, ion-implanted germanium has revealed an anomalous near-surface yield deficit. Implant dose and species dependencies and the effect of annealing have been examined. A marked loss of implanted impurity was also noted. The yield deficit is attributed to the absorption of oxygen and other light mass contaminants into a highly porous implanted layer upon exposure to air. Loss of implant species is attributed to enhanced sputtering effects

Computer simulation program for medium-energy ion scattering and Rutherford backscattering spectrometry

Science.gov (United States)

Nishimura, Tomoaki

2016-03-01

A computer simulation program for ion scattering and its graphical user interface (MEISwin) has been developed. Using this program, researchers have analyzed medium-energy ion scattering and Rutherford backscattering spectrometry at Ritsumeikan University since 1998, and at Rutgers University since 2007. The main features of the program are as follows: (1) stopping power can be chosen from five datasets spanning several decades (from 1977 to 2011), (2) straggling can be chosen from two datasets, (3) spectral shape can be selected as Gaussian or exponentially modified Gaussian, (4) scattering cross sections can be selected as Coulomb or screened, (5) simulations adopt the resonant elastic scattering cross section of 16O(4He, 4He)16O, (6) pileup simulation for RBS spectra is supported, (7) natural and specific isotope abundances are supported, and (8) the charge fraction can be chosen from three patterns (fixed, energy-dependent, and ion fraction with charge-exchange parameters for medium-energy ion scattering). This study demonstrates and discusses the simulations and their results.

Selective Rutherford backscattering techniques in the study of transition-metal implanted YBa{sub 2}C{sub 3}O{sub 7-{delta}}

Energy Technology Data Exchange (ETDEWEB)

Martin, J.W.; Russell, G.J. [New South Wales Univ., Kensington, NSW (Australia). School of Physics; Cohen, D.D.; Evans, P.J. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1993-12-31

Using a metal-vapor vacuum arc ion source, several as-grown, large single crystal YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} were implanted with a dose of 1x10{sup 17} zinc, nickel and iron ions. After implantation the crystal was subjected to two anneal cycles that has allowed to examine crystal structure, superconducting transitions and composition, through X-ray diffraction, rutherford backscattering spectroscopy (RBS) and AC susceptibility measurements respectively. Although RBS discriminates strongly against light elements, such as oxygen, the use of resonant reaction {sup 16}O ({alpha}, {alpha}){sup 16}O at 3.4 MeV was beneficial, as its cross section is nearly 23 times that of the rutherford cross section. 4 figs.

Selective Rutherford backscattering techniques in the study of transition-metal implanted YBa{sub 2}C{sub 3}O{sub 7-{delta}}

Energy Technology Data Exchange (ETDEWEB)

Martin, J W; Russell, G J [New South Wales Univ., Kensington, NSW (Australia). School of Physics; Cohen, D D; Evans, P J [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1994-12-31

Using a metal-vapor vacuum arc ion source, several as-grown, large single crystal YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} were implanted with a dose of 1x10{sup 17} zinc, nickel and iron ions. After implantation the crystal was subjected to two anneal cycles that has allowed to examine crystal structure, superconducting transitions and composition, through X-ray diffraction, rutherford backscattering spectroscopy (RBS) and AC susceptibility measurements respectively. Although RBS discriminates strongly against light elements, such as oxygen, the use of resonant reaction {sup 16}O ({alpha}, {alpha}){sup 16}O at 3.4 MeV was beneficial, as its cross section is nearly 23 times that of the rutherford cross section. 4 figs.

Determination of surface oxide compositions on Alloy 600 using Rutherford backscattering

International Nuclear Information System (INIS)

Hanson, A.L.; Kraner, H.W.

1984-01-01

The surface composition of oxides formed on Alloy 600 under conditions similar to those in the primary side of PWR heat exchangers has been studied as a function of potential using Rutherford backscattering and proton inelastic scattering. Electropolished samples of Alloy 600 were exposed at several potentials to a solution of 0.18M H 3 BO 3 (2000ppm B) with 0.21mM LiOH (1.5ppm Li) at 300 0 C for 450 hours. The potentials relative to an internal hydrogen electrode ranged from -.09 to 750 mV. RBS analysis showed little or no oxide formation on samples exposed at 0 mV. Above 0 mV oxide layers formed whose thicknesses increased with potential. In addition the RBS showed a significantly enhanced concentration of aluminum and silicon in oxide. Both the oxygen and the sum of the aluminum and silicon content appeared to maintain a fixed surface concentration independent of the oxide thickness. Boron and lithium concentrations were analyzed with proton inelastic scattering. No lithium was detected in any sample. The boron concentration was found to follow the thickness of the oxide

Determination of surface oxide compositions on Alloy 600 using Rutherford backscattering

International Nuclear Information System (INIS)

Hanson, A.L.; Isaacs, H.S.; Kraner, H.W.

1984-01-01

The surface composition of oxides formed on Alloy 600 under conditions similar to those in the primary side of PWR heat exchangers has been studied as a function of potential using Rutherford backscattering and proton inelastic scattering. Electropolished samples of Alloy 600 were exposed at several potentials to a solution of 0.18M H 3 BO 3 (2000 ppM B) with 0.28M LiOH (1.4 ppM Li) at 300 0 C for 450 hours. The potentials relative to an internal hydrogen electrode ranged from -.09 to 750 mV. RBS analysis showed little or no oxide formation on samples exposed at 0 mV. Above 0 mV oxide layers formed whose thicknesses increased with potential. In addition the RBS showed a significantly enhanced concentration of aluminum and silicon in oxide. Both the oxygen and the sum of the aluminum and silicon content appeared to maintain a fixed surface concentration independent of the oxide thickness. Boron and lithium concentration were analyzed with proton inelastic scattering. No lithium was found in any sample. The boron concentration was found to follow the thickness of the oxide

Characterization of cesium diffusion behavior into granite matrix using Rutherford backscattering spectrometry

Science.gov (United States)

Tsai, Shih-Chin; Lee, Chuan-Pin; Tsai, Tsuey-Lin; Yu, Yueh-Chung

2017-10-01

The characterization of radionuclide diffusion behavior is necessary for performance assessment of granite as a geological barrier for high-level radioactive waste disposal. Rutherford backscattering spectrometry (RBS), a novel nuclear ion-beam technique, was selected in this study because it is suitable for analyzing the concentration gradients of heavy elements in a well-defined matrix and allows measuring diffusion coefficients on a micrometer scale. In this study Cs was selected to represent Cs-135 (a key radionuclide in high-level waste) diffusion in granite. The Cs energy spectrum and concentration deep profile were analyzed and the diffusion coefficient of Cs in granite for three different locations were determined, which were 2.06 × 10-19m2 s-1, 3.58 × 10-19m2 s-1, and 7.19 × 10-19m2 s-1-19m2 s-19m2 s-1, respectively, which were of a similiar order of magnitude. Results from other studies are also compared and discussed in this paper.

Computer simulation program for medium-energy ion scattering and Rutherford backscattering spectrometry

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Tomoaki, E-mail: t-nishi@hosei.ac.jp

2016-03-15

A computer simulation program for ion scattering and its graphical user interface (MEISwin) has been developed. Using this program, researchers have analyzed medium-energy ion scattering and Rutherford backscattering spectrometry at Ritsumeikan University since 1998, and at Rutgers University since 2007. The main features of the program are as follows: (1) stopping power can be chosen from five datasets spanning several decades (from 1977 to 2011), (2) straggling can be chosen from two datasets, (3) spectral shape can be selected as Gaussian or exponentially modified Gaussian, (4) scattering cross sections can be selected as Coulomb or screened, (5) simulations adopt the resonant elastic scattering cross section of {sup 16}O({sup 4}He, {sup 4}He){sup 16}O, (6) pileup simulation for RBS spectra is supported, (7) natural and specific isotope abundances are supported, and (8) the charge fraction can be chosen from three patterns (fixed, energy-dependent, and ion fraction with charge-exchange parameters for medium-energy ion scattering). This study demonstrates and discusses the simulations and their results.

Characterization of gold nanoparticle films: Rutherford backscattering spectroscopy, scanning electron microscopy with image analysis, and atomic force microscopy

Directory of Open Access Journals (Sweden)

Pia C. Lansåker

2014-10-01

Full Text Available Gold nanoparticle films are of interest in several branches of science and technology, and accurate sample characterization is needed but technically demanding. We prepared such films by DC magnetron sputtering and recorded their mass thickness by Rutherford backscattering spectroscopy. The geometric thickness dg—from the substrate to the tops of the nanoparticles—was obtained by scanning electron microscopy (SEM combined with image analysis as well as by atomic force microscopy (AFM. The various techniques yielded an internally consistent characterization of the films. In particular, very similar results for dg were obtained by SEM with image analysis and by AFM.

Application of the Rutherford backscattering analysis (RBS analysis) for detecting heavy impurity elements in pBN crucible materials

International Nuclear Information System (INIS)

Bethge, K.; Meyer, J.D.; Michelmann, R.; Krauskopf, J.

1992-01-01

By means of the Rutherford backscattering analysis evidence is given of an inhomogeneous depth distribution of the elements C, O, F, Na, Mg, Al, Si, P, S, Cl, Ca, Ti, Cr, Fe, Ni in pBN (pyrolytic boron nitride) materials of crucibles. This inhomogenous distribution is observed both at the original surface and at the surface of inner cracks. In addition, the distribution of the elements is found to differ depending on the spots chosen for analysis. The RBS measurements alone do not yield information on the volume concentration of the elements. (orig.) With 2 refs [de

Characterization of amorphous silicon films by Rutherford backscattering spectrometry. [1. 5-MeV Ho/sup +/

Energy Technology Data Exchange (ETDEWEB)

Kubota, K; Imura, T; Iwami, M; Hiraki, A [Osaka Univ., Suita (Japan). Dept. of Electrical Engineering; Satou, M [Government Industrial Research Inst., Osaka, Ikeda (Japan); Fujimoto, F [Tokyo Univ. (Japan). Coll. of General Education; Hamakawa, Y [Osaka Univ., Toyonaka (Japan). Faculty of Engineering Science; Minomura, S [Tokyo Univ. (Japan). Inst. for Solid State Physics; Tanaka, K [Electrotechnical Lab., Tanashi, Tokyo (Japan)

1980-01-01

Rutherford backscattering spectrometry (RBS) was applied to the characterization of amorphous silicon films prepared by glow discharge in silane, tetrode- and diode-sputterings of silicon target in ambient argon or hydrogen diluted by argon. This method was able to detect at least 5 at.% hydrogen atoms in amorphous silicon through the change of stopping power. Hydrogen content in films made by glow discharge at the substrate temperature 25/sup 0/C to 300/sup 0/C and at 2 torr of silane gas varied from 50% to 20%. A strong trend was found for oxygen to dissolve into films: Films produced by diode sputtering in argon gas with higher pressure than 3 x 10/sup -2/ torr absorbed oxygen. The potential and fitness of the RBS method for the characterization of amorphous silicon films are emphasized and demonstrated.

The application of low angle Rutherford backscattering and channelling techniques to determine implantation induced disorder profile distributions in semiconductors

International Nuclear Information System (INIS)

Ahmed, N.A.G.; Christodoulides, C.E.; Carter, G.; Nobes, M.J.; Titov, A.I.

1980-01-01

Low angle exit (9 0 ) Rutherford backscattering geometry and channelling of 2 MeV 4 He + are employed to investigate the disorder depth profiles created by 40 keV N + implantation in (111) silicon and (100) GaAs targets. Parameters which can influence the disordering rate and its spatial distribution, such as ion fluence flux, substrate type and substrate temperature are examined. Under certain implantation conditions, the damage profile distributions are asymmetric - exhibiting a bimodal form in silicon targets or confined much closer to the GaAs surface than the normally expected mean range of 40 keV N + ions. (orig.)

Rutherford Backscattering and Channeling Studies of Al and Mg Diffusion in Iron Oxide Thin Films

International Nuclear Information System (INIS)

Thevuthasan, Theva; McCready, David E.; Jiang, Weilin; Mcdaniel, Emily P.; Yi, Sang I.; Chambers, Scott A.; J.L. Duggan and I.L. Morgan

1999-01-01

Thin films of alpha-Fe2O3(0001) (hermatite) and gamma-Fe2O3 (001) (maghemite) were epitaxially grown on Al2O3(0001) substrates, respectively, using the new molecular beam epitaxy (MBE) system at the Environmental Molecular Sciences Laboratory (EMSL). We have investigated the crystalline quality of these films using Rutherford Backscattering (RBS) and channeling experiments. Minimum yields obtained from aligned and random spectra are 2.7+-0.3% for the alpha-Fe2o3(0001) film and 14.5+-0.6% for the gamma-Fe2O3 (001) film. Al and Mg outdiffusion into the hematite and maghemite films were observed at higher temperatures. Indiffusion of Fe atoms from the film into the substrate was observed for the gamma-Fe2o3(001)/MgO(001) system. In contrast, no Fe indiffusion was observed for the sapphire substrate

Trace element determination in tomato puree using particle induced X-ray emission and Rutherford backscattering

International Nuclear Information System (INIS)

Romero-Davila, E.; Miranda, J.

2004-01-01

Particle induced X-ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) were used to determine the concentrations of trace elements in samples of 12 tomato puree brands sold in the Mexican market. While RBS offered information about the main elements present in the matrix, PIXE gave results on trace elements. As a whole, data for 17 elements (C, N, O, Na, Mg, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, and Zn) were obtained. To evaluate the results, a comparison with brands from USA, Japan, Colombia, and Chile was carried out, using tomato purees produced following the domestic technology recipe. Additionally, the results were considered in the light of the Codex Alimentarius and the Mexican standard. It was found that all of the brands fall within the limits established by these standards, being of the same order of magnitude as the foreign brands. (author)

Study of SiO2 surface sputtering by a 250-550 keV He+ ion beam during high-resolution Rutherford backscattering measurements

International Nuclear Information System (INIS)

Kusanagi, Susumu; Kobayashi, Hajime

2006-01-01

Decreases in oxygen signal intensities in spectra of high-resolution Rutherford backscattering spectrometry (HRBS) were observed during measurements on a 5-nm thick SiO 2 layer on a Si substrate when irradiated by 250-550 keV He + ions. Shifts in an implanted arsenic profile in a 5-nm thick SiO 2 /Si substrate were also observed as a result of He + ion irradiation. These results lead to the conclusion that the SiO 2 surface was sputtered by He + ions in this energy range

Artificial neural networks for automation of Rutherford backscattering spectroscopy experiments and data analysis

International Nuclear Information System (INIS)

Barradas, N.P.; Vieira, A.; Patricio, R.

2002-01-01

We present an algorithm based on artificial neural networks able to determine optimized experimental conditions for Rutherford backscattering measurements of Ge-implanted Si. The algorithm can be implemented for any other element implanted into a lighter substrate. It is foreseeable that the method developed in this work can be applied to still many other systems. The algorithm presented is a push-button black box, and does not require any human intervention. It is thus suited for automated control of an experimental setup, given an interface to the relevant hardware. Once the experimental conditions are optimized, the algorithm analyzes the final data obtained, and determines the desired parameters. The method is thus also suited for automated analysis of the data. The algorithm presented can be easily extended to other ion beam analysis techniques. Finally, it is suggested how the artificial neural networks required for automated control and analysis of experiments could be automatically generated. This would be suited for automated generation of the required computer code. Thus could RBS be done without experimentalists, data analysts, or programmers, with only technicians to keep the machines running

Investigation of high temperature reactions on graphite with Rutherford backscattering spectrometry: interaction of cadmium, lead and silver with a phosphate modifier

Energy Technology Data Exchange (ETDEWEB)

Eloi, C.; Robertson, J.D.; Majidi, V. (Kentucky Univ., Lexington, KY (United States))

1993-03-01

The depth-dependent concentration profiles of nitrate salts of Pb, Cd and Ag were observed with and without the addition of (NH[sub 4])H[sub 2]PO[sub 4] chemical modifier using Rutherford backscattering spectrometry (RBS). The RBS results demonstrate that the analytes, in all the systems investigated, readily migrate ([>=]3 [mu]m) into the pyrolytic graphite coated graphite substrate at room temperature. The stabilization of Cd and Pb with the phosphate modifier is proposed to be due to the formation of a phosphate glass. Silver did not extensively interact with the phosphate modifier and was, as a result, not stabilized. (author).

Investigation of high temperature reactions on graphite with Rutherford backscattering spectrometry: interaction of cadmium, lead and silver with a phosphate modifier

International Nuclear Information System (INIS)

Eloi, C.; Robertson, J.D.; Majidi, V.

1993-01-01

The depth-dependent concentration profiles of nitrate salts of Pb, Cd and Ag were observed with and without the addition of (NH 4 )H 2 PO 4 chemical modifier using Rutherford backscattering spectrometry (RBS). The RBS results demonstrate that the analytes, in all the systems investigated, readily migrate (≥3 μm) into the pyrolytic graphite coated graphite substrate at room temperature. The stabilization of Cd and Pb with the phosphate modifier is proposed to be due to the formation of a phosphate glass. Silver did not extensively interact with the phosphate modifier and was, as a result, not stabilized. (author)

Auger electron spectroscopy and Rutherford backscattering studies of copper in 2024-T3 aluminum following electrochemical anodization in phosphoric acid

Science.gov (United States)

Solomon, J. S.

1981-05-01

The effects of the electrochemical anodization of dioxidized 2024-T3 aluminum on copper were characterized by Auger electron spectroscopy and Rutherford backscattering. Anodization was performed in phosphoric acid at constant potential. Data is presented which shows that constant potential anodization of 2024-T3 is more efficient than aluminum in terms of oxide growth rates for short anodization times. However the maximum anodic oxide thickness achievable on the alloy is less than the pure metal. Copper is shown to be enriched at the oxide metal interface because of its diffusion from the bulk during anodization. The presence of copper at the oxide-metal interface is shown to affect oxide morphology.

Investigation of high temperature reactions on solid substrates with Rutherford backscattering spectrometry: interaction of palladium with selenium on heated graphite surfaces

International Nuclear Information System (INIS)

Majidi, V.; Robertson, J.D.

1991-01-01

Selenium and palladium interactions on heated pyrolytically coated graphite substrates were investigated using Rutherford backscattering spectrometry. The studies were performed using selenium alone, palladium alone, and a combination of selenium and palladium deposited on the graphite substrates. The results indicate that palladium instantaneously stabilizes selenium at ambient temperatures and prevents the diffusion of selenium into the graphite. As the substrate is heated, temperature dependent diffusion of all analytes into the graphite is observed. Furthermore, it appears that the stabilization of selenium is due to the formation of a stoichiometric compound with palladium and oxygen. This compound decomposes at a temperature between 1070 and 1770 K. (author)

Investigation of high temperature reactions on solid substrates with Rutherford backscattering spectrometry: interaction of palladium with selenium on heated graphite surfaces

Energy Technology Data Exchange (ETDEWEB)

Majidi, V.; Robertson, J.D. (Kentucky Univ., Lexington, KY (United States). Dept. of Chemistry)

1991-01-01

Selenium and palladium interactions on heated pyrolytically coated graphite substrates were investigated using Rutherford backscattering spectrometry. The studies were performed using selenium alone, palladium alone, and a combination of selenium and palladium deposited on the graphite substrates. The results indicate that palladium instantaneously stabilizes selenium at ambient temperatures and prevents the diffusion of selenium into the graphite. As the substrate is heated, temperature dependent diffusion of all analytes into the graphite is observed. Furthermore, it appears that the stabilization of selenium is due to the formation of a stoichiometric compound with palladium and oxygen. This compound decomposes at a temperature between 1070 and 1770 K. (author).

Study of SiO{sub 2} surface sputtering by a 250-550 keV He{sup +} ion beam during high-resolution Rutherford backscattering measurements

Energy Technology Data Exchange (ETDEWEB)

Kusanagi, Susumu [Materials Analysis Laboratory, Advanced Design Technology Center, Sony Corporation, 4-16-1 Okata Atsugi-shi, Kanagawa 243-0021 (Japan)]. E-mail: susumu.kusanagi@jp.sony.com; Kobayashi, Hajime [Materials Analysis Laboratory, Advanced Design Technology Center, Sony Corporation, 4-16-1 Okata Atsugi-shi, Kanagawa 243-0021 (Japan)

2006-08-15

Decreases in oxygen signal intensities in spectra of high-resolution Rutherford backscattering spectrometry (HRBS) were observed during measurements on a 5-nm thick SiO{sub 2} layer on a Si substrate when irradiated by 250-550 keV He{sup +} ions. Shifts in an implanted arsenic profile in a 5-nm thick SiO{sub 2}/Si substrate were also observed as a result of He{sup +} ion irradiation. These results lead to the conclusion that the SiO{sub 2} surface was sputtered by He{sup +} ions in this energy range.

A Strange Box and a Stubborn Brit: Rutherford's Experiments with Alpha Particles.

Science.gov (United States)

Digilov, M.

1991-01-01

Discusses 5 innovative experiments conducted by Rutherford in early 1900s utilizing the 30 milligrams of radium salt he personally carried from Europe to Canada in 1903. Traces his work with alpha particles from his original results which determined their nature, charge, and mass, to his technique of backscattering which helped to advance…

Lattice location of O{sup 18} in ion implanted Fe crystals by Rutherford backscattering spectrometry, channeling and nuclear reaction analysis

Energy Technology Data Exchange (ETDEWEB)

Vairavel, Mathayan; Sundaravel, Balakrishnan, E-mail: bsundar@igcar.gov.in; Panigrahi, Binaykumar

2016-09-15

There are contradictory theoretical predictions of lattice location of oxygen interstitial atom at tetrahedral and octahedral interstices in bcc Fe. For validating these predictions, 300 keV O{sup 18} ions with fluence of 5 × 10{sup 15} ions/cm{sup 2} are implanted into bcc Fe single crystals at room temperature and annealed at 400 °C. The Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA)/channeling measurements are carried out with 850 keV protons. The lattice location of implanted O{sup 18} is analysed using the α-particles yield from O{sup 18}(p,α)N{sup 15} nuclear reaction. The tilt angular scans of α-particle yield along 〈110〉 and 〈100〉 axial directions are performed at room temperature. Lattice location of O{sup 18} is found to be at tetrahedral interstitial site by comparing the experimental scan with simulated scans using FLUX7 software.

Nanometric resolution in glow discharge optical emission spectroscopy and Rutherford backscattering spectrometry depth profiling of metal (Cr, Al) nitride multilayers

International Nuclear Information System (INIS)

Escobar Galindo, R.; Gago, R.; Fornies, E.; Munoz-Martin, A.; Climent Font, A.; Albella, J.M.

2006-01-01

In this work, we address the capability of glow discharge optical emission spectroscopy (GDOES) for fast and accurate depth profiling of multilayer nitride coatings down to the nanometer range. This is shown by resolving the particular case of CrN/AlN structures with individual thickness ranging from hundreds to few nanometers. In order to discriminate and identify artefacts in the GDOES depth profile due to the sputtering process, the layered structures were verified by Rutherford backscattering spectrometry (RBS) and scanning electron microscopy (SEM). The interfaces in the GDOES profiles for CrN/AlN structures are sharper than the ones measured for similar metal multilayers due to the lower sputtering rate of the nitrides. However, as a consequence of the crater shape, there is a linear degradation of the depth resolution with depth (approximately 40 nm/μm), saturating at a value of approximately half the thickness of the thinner layer. This limit is imposed by the simultaneous sputtering of consecutive layers. The ultimate GDOES depth resolution at the near surface region was estimated to be of 4-6 nm

Stoichiometry and local bond configuration of In{sub 2}S{sub 3}:Cl thin films by Rutherford backscattering spectrometry

Energy Technology Data Exchange (ETDEWEB)

Juma, Albert O., E-mail: jumaa@biust.ac.bw

2016-10-15

In{sub 2}S{sub 3} thin films deposited using chemical methods always contain residual elements from the precursors, which modify their properties. As buffer layers in solar cells, the residual elements in the In{sub 2}S{sub 3} layer affect the performance of these devices. The stoichiometry of In{sub 2}S{sub 3} thin films deposited by spray ion layer gas reaction (ILGAR) was studied as a function of the residual Cl from InCl{sub 3} precursor by varying the deposition parameters. The chemical formula was deduced from the elemental composition determined using Rutherford backscattering (RBS). Incomplete sulfurization of the precursor implies that residual Cl{sup −} remains bonded to the In{sup 3+} ions while some occupy interstitial and/or antisite positions in the In{sub 2}S{sub 3} matrix. This results in thin films with different stoichiometry, described by the formula In{sub 4}S{sub 6−x}Cl{sub 2x+2y}. This changes the local bond configuration and geometry and underpins the influence of residual Cl on the physical properties of In{sub 2}S{sub 3} thin films.

Surface structure analysis by means of Rutherford scattering: methods to study surface relaxation

International Nuclear Information System (INIS)

Turkenburg, W.C.; Soszka, W.; Saris, F.W.; Kersten, H.H.; Colenbrander, B.G.

1976-01-01

The use of Rutherford backscattering for structural analysis of single crystal surfaces is reviewed, and a new method is introduced. With this method, which makes use of the channeling and blocking phenomenon of light ions of medium energy, surface atoms can be located with a precision of 0.02 A. This is demonstrated in a measurement of surface relaxation for the Cu(110) surface. (Auth.)

Interaction of europium and nickel with calcite studied by Rutherford Backscattering Spectrometry and Time-Resolved Laser Fluorescence Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Sabau, A. [Agence Nationale pour la gestion des Déchets RAdioactifs, 1-7 rue J. Monnet, Parc de la Croix Blanche, 92298 Châtenay-Malabry Cedex (France); Université de Nice Sophia Antipolis, Ecosystèmes Côtiers Marins et Réponses aux Stress (ECOMERS), 28 avenue Valrose, 06108 Nice Cedex 2 (France); Pipon, Y., E-mail: pipon@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Institut Universitaire de Technologie (IUT) Lyon-1, Université Claude Bernard Lyon 1, 69 622 Villeurbanne Cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); CEA/DEN, Saclay, 91191 Gif sur Yvette (France); Lomenech, C. [Université de Nice Sophia Antipolis, Ecosystèmes Côtiers Marins et Réponses aux Stress (ECOMERS), 28 avenue Valrose, 06108 Nice Cedex 2 (France); Jordan, N. [Helmholtz Zentrum Dresden Rossendorf (HZDR), Institute of Resource Ecology (IRE) (Germany); Moncoffre, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Barkleit, A. [Helmholtz Zentrum Dresden Rossendorf (HZDR), Institute of Resource Ecology (IRE) (Germany); and others

2014-08-01

This study aims at elucidating the mechanisms regulating the interaction of Eu and Ni with calcite (CaCO{sub 3}). Calcite powders or single crystals (some mm sized) were put into contact with Eu or Ni solutions at concentrations ranging from 10{sup −3} to 10{sup −5} mol L{sup −1} for Eu and 10{sup −3} mol L{sup −1} for Ni. The sorption durations ranged from 1 week to 1 month. Rutherford Backscattering Spectrometry (RBS) well adapted to discriminate incorporation processes such as: (i) adsorption or co precipitation at the mineral surfaces or, (ii) incorporation into the mineral structure (through diffusion for instance), has been carried out. Moreover, using the fluorescence properties of europium, the results have been compared to those obtained by Time-Resolved Laser Fluorescence Spectroscopy (TRLFS) on calcite powders. For the single crystals, complementary SEM observations of the mineral surfaces at low voltage were also performed. Results showed that Ni accumulates at the calcite surface whereas Eu is also incorporated at a greater depth. Eu seems therefore to be incorporated into two different states in calcite: (i) heterogeneous surface accumulation and (ii) incorporation at depth greater than 160 nm after 1 month of sorption. Ni was found to accumulate at the surface of calcite without incorporation.

Optimalization study for ion-temperature measurements by means of Rutherford scattering

International Nuclear Information System (INIS)

Donne, A.J.H.; Barbian, E.P.

1986-03-01

Small-angle Rutherford scattering of energetic neutrals by plasma ions is governed by energy and momentum conservation. The FWHM of the scattering distibution reveals the ion temperature of the plasma. A feasibility study is performed to optimize the parameters in case Rutherford-scattering technique is applied to a medium-sized tokamak experiment. Together with a time-of-flight analyser with a high energy resolution of about 100, a 20 keV helium probing beam with a neutral current density of 10 A/m 2 can provide a detailed spectrum within 3 ms, from which the ion temperature can be extracted with an accuracy of better than 10%. The influence of plasma impurities and resonant charge exchange on the scattering process is discussed in detail. The good spatial resolution makes the method very suitable to investigate energy deposition profiles in the case of ion-cyclotron radiation applied to the plasma for the purpose of plasma heating. (orig.)

The potential of materials analysis by electron rutherford backscattering as illustrated by a case study of mouse bones and related compounds.

Science.gov (United States)

Vos, Maarten; Tökési, Károly; Benkö, Ilona

2013-06-01

Electron Rutherford backscattering (ERBS) is a new technique that could be developed into a tool for materials analysis. Here we try to establish a methodology for the use of ERBS for materials analysis of more complex samples using bone minerals as a test case. For this purpose, we also studied several reference samples containing Ca: calcium carbonate (CaCO(3)) and hydroxyapatite and mouse bone powder. A very good understanding of the spectra of CaCO(3) and hydroxyapatite was obtained. Quantitative interpretation of the bone spectrum is more challenging. A good fit of these spectra is only obtained with the same peak widths as used for the hydroxyapatite sample, if one allows for the presence of impurity atoms with a mass close to that of Na and Mg. Our conclusion is that a meaningful interpretation of spectra of more complex samples in terms of composition is indeed possible, but only if widths of the peaks contributing to the spectra are known. Knowledge of the peak widths can either be developed by the study of reference samples (as was done here) or potentially be derived from theory.

Standards for backscattering analysis

International Nuclear Information System (INIS)

Mitchell, I.V.; Eschbach, H.L.

1978-01-01

The need for backscattering standards appears to be twofold and depends on the uses and requirements of the users. The first is as a calibrated reference by which samples of a similar nature to the standard may be absolutely compared. The second is as a means of intercomparing the relative results obtained by different laboratories using, as near as possible, identical samples. This type of comparison is of a relative nature and the absolute values are not necessarily required. In the present work the authors try to satisfy both needs by providing identical samples which have been absolutely calibrated to a high accuracy. Very thin copper and vanadium layers were evaporated onto bismuth implanted silicon crystals and on glass plates under carefully controlled conditions. The mass of the deposits was determined in situ using a sensitive UHV microbalance. In addition, two quartz oscillator monitors were used. The samples have been analysed by Rutherford backscattering and the absolute quantity of bismuth determined by a comparison with the known amounts of deposited material. (Auth.)

On the annealing behaviour of dysprosium ion implanted nickel: a combined study using Rutherford backscattering, transmission electron microscopy, and total current spectroscopy

International Nuclear Information System (INIS)

Chadderton, L.T.; Johnson, E.

1977-01-01

Despite continuing improvements in applications of the analytical method of Rutherford backscattering (RBS) to solid state physics it is recognized that more complete information can be obtained if other techniques - for example transmission electron microscopy (TEM) - are employed simultaneously. Experiments are described in which a combined RBS and TEM study of the annealing of nickel, rendered amorphous by implantation of 20 keV dysprosium ions is supplemented with a completely new technique - total current spectroscopy (TCS). In TCS low energy electrons (0-15 eV) are used to probe the damaged nickel. Observations have been made during annealing of both the reappearance of the bulk band structure of the metal and of a 'surface peak' which is highly sensitive to the recovery process. Changes in the height of the surface peak reveal three sharp annealing stages, the first two being preceded by reverse annealing which correlates well with RBS and TEM results. The first annealing stage - following the amorphous to crystalline transition - may be associated with electronic effects in the vicinity of the Curie point. Changes in the position of the surface peak allow one to trace the diffusion of dysprosium to the surface. Quantum mechanical resonances at the damage/crystal interface have also been followed throughout annealing. The initially amorphous layer (approximately 2.2nm) increases in thickness slightly during recovery. (Auth.)

Working with Rutherford

International Nuclear Information System (INIS)

Oliphant, M.

1984-01-01

The author describes what it was like to work with Rutherford at the Cavendish Laboratory in the early 1930's. The memories are detailed and the anecdotes recounted give a vivid account of Rutherford at that time. Some experiments on heavy water are described. In one, deuterium nuclei were fused to form a new isotope of hydrogen of atomic mass 3, tritium. An alternative reaction of two deuterons produced a neutron and a helium particle of mass 3, helium-3. (UK)

The use of ion beam analysis in the synthesis of materials. A review of the determination of light elements by high-energy resonant backscattering

International Nuclear Information System (INIS)

Nastasi, M.

1999-01-01

For the ion synthesis of materials plasma inversion ion processing (PIIP) technology, has been applied in the framework of materials science research. The characteristics of this technique are discussed. PIIP has been complemented and compared with alpha-particle Rutherford Backscattering Spectrometry (RBS) High-energy Backscattering Spectrometry (HEBS) is the third material testing method for comparison. Examples for each technology are presented and discussed. (R.P.)

Rutherford back-scattering and X-ray fluorescence for the study of corroded surfaces

International Nuclear Information System (INIS)

Chaudhri, M. Anwar

2010-01-01

A combination of Rutherford-Back-Scattering (RBS) and X-Ray Fluorescence Analysis (XRF) has been used to study the corroded inside surfaces of some tooth-paste tubes, which were causing a significant loss of the product. This greyish-brown, thin, corrosion layer on the inside of the tooth-paste tube is easily distinguishable from brand new, as well as from non-corroded used tubes, which are made of 99.7 % Al. The unused clean aluminium tube shows some copper traces (about 0.3 mg/cm 2 ) on the surface, which almost disappears from the surface of the non-corroded used tube but reappears, to a lesser extent, on the surface of the corroded tube. The corroded layer has been found to consist mainly of P and Ca (about 1 mg/cm 2 each) with smaller quantities of Na, Mg, Si, S and Cl. (authors)

Rutherford-Bohr atom

Science.gov (United States)

Heilbron, J. L.

1981-03-01

Bohr used to introduce his attempts to explain clearly the principles of the quantum theory of the atom with an historical sketch, beginning invariably with the nuclear model proposed by Rutherford. That was sound pedagogy but bad history. The Rutherford-Bohr atom stands in the middle of a line of work initiated by J.J. Thomson and concluded by the invention of quantum mechanics. Thompson's program derived its inspiration from the peculiar emphasis on models characteristic of British physics of the 19th century. Rutherford's atom was a late product of the goals and conceptions of Victorian science. Bohr's modifications, although ultimately fatal to Thomson's program, initially gave further impetus to it. In the early 1920s the most promising approach to an adequate theory of the atom appeared to be the literal and detailed elaboration of the classical mechanics of multiply periodic orbits. The approach succeeded, demonstrating in an unexpected way the force of an argument often advanced by Thomson: because a mechanical model is richer in implications than the considerations for which it was advanced, it can suggest new directions of research that may lead to important discoveries.

Investigation of the interaction of Greek dolomitic marble with metal aqueous solutions using Rutherford backscattering and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Godelitsas, A.; Kokkoris, M.; Misaelides, P.

2005-01-01

The interaction of dolomitic marble from Thassos Island (northern Aegean sea, Greece) with Co 2+ -, Cd 2+ -, Pb 2+ - and Cr 3+ - aqueous solutions (metal concentration: 1000 mgL -1 ) was investigated using Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS). The initial material as well as the interaction products were also characterized by scanning electron microscopy (SEM/EDS), radioisotope induced X-ray fluorescence analysis (RI-XRFA), powder X-ray diffraction (Powder-XRD) and Fourier transform infra-red spectroscopy (FT-IR). The contact time of the samples with the aqueous solutions was one week and took place under ambient temperature. To our knowledge, the sorption of the above mentioned metals with dolomite (CaMg(CO 3 ) 2 ) has not yet been presented in the literature and the only data available concern the adsorption of Ca, Mg and Nd from NaCl solutions. The Thassos island dolomitic marble is a snow-white homogeneous carbonate metamorphic rock, with fine physicochemical and mechanical properties, currently used as natural building stone in many parts of the world (see http://www.thassosmarble.com), This dolomite-bearing material was also extensively used in the past as construction material of many .classical Greek and Roman sculptures and architectural elements; in 301 AD the Roman emperor Diocletian included 'Thassian marble' in the list of the 19 most expensive and important 'marbles' produced in the imperial quarries. Previous literature presented the isotopic analysis(δ 13 C, δ 18 O) and EPR studies (Mn 2+ and Fe 3+ ) of this stone. The obtained results indicated a limited Cd 2+ - and Co 2+ -sorption on the dissolved surface of the carbonate substrate, whereas, under the same experimental conditions, the Pb 2+ - and Cr 3+ -interaction is more intense leading to extended overgrowth of crystalline Pb-carbonates and surface precipitation of amorphous Cr-hydroxides/oxyhydroxides.

Ion backscattering techniques applied in materials science research

International Nuclear Information System (INIS)

Sood, D.K.

1978-01-01

The applications of Ion Backscattering Technique (IBT) to material analysis have expanded rapidly during the last decade. It is now regarded as an analysis tool indispensable for a versatile materials research program. The technique consists of simply shooting a beam of monoenergetic ions (usually 4 He + ions at about 2 MeV) onto a target, and measuring their energy distribution after backscattering at a fixed angle. Simple Rutherford scattering analysis of the backscattered ion spectrum yields information on the mass, the absolute amount and the depth profile of elements present upto a few microns of the target surface. The technique is nondestructive, quick, quantitative and the only known method of analysis which gives quantitative results without recourse to calibration standards. Its major limitations are the inability to separate elements of similar mass and a complete absence of chemical-binding information. A typical experimental set up and spectrum analysis have been described. Examples, some of them based on the work at the Bhabha Atomic Research Centre, Bombay, have been given to illustrate the applications of this technique to semiconductor technology, thin film materials science and nuclear energy materials. Limitations of IBT have been illustrated and a few remedies to partly overcome these limitations are presented. (auth.)

Rutherford, Radioactivity and the Origins of Nuclear Physics

International Nuclear Information System (INIS)

Hughes, J

2012-01-01

When Ernest Rutherford became Professor of Physics at Manchester University in 1907, he brought with him the research field in which he had played a leading role over the previous few years: radioactivity. Rutherford turned the Manchester physics lab over to studies of radioactivity and radiation, and through his own work and that of his many collaborators and students, established Manchester as a major international centre in atomic physics. It was out of this powerhouse that the nuclear theory of the atom emerged in 1911. In 1917, Rutherford 'disintegrated' the nitrogen nucleus using α-particles, opening up the possibility of nuclear structure. At Cambridge's Cavendish Laboratory from 1919, Rutherford and his co-workers began to explore the constitution of the nucleus. With Chadwick, Aston and others, Rutherford turned his research school to the emergent field of nuclear physics – a field he dominated (though not without controversy) until his death in 1937. Exploring the intellectual, material and institutional cultures of early twentieth century physics, this paper will outline the background to Rutherford's career and work, the experimental and theoretical origins of nuclear theory of the atom and the early development of nuclear physics. (rutherford centennial conference on nuclear physics university of manchester 8-12 august 2011)

Rutherford's war

Science.gov (United States)

Campbell, John

2016-02-01

Seagulls, sea lions and the comic-book hero Professor Radium were all recruited to fight the threat of submarines during the First World War. But as John Campbell explains, it was Ernest Rutherford who led the way a century ago in using acoustics to deter these deadly craft.

Ernest Rutherford: scientist supreme

International Nuclear Information System (INIS)

Campbell, J.

1998-01-01

One hundred years ago this month, Ernest Rutherford a talented young New Zealander who had just spent three years as a postgraduate student in Britain left for Canada, where he was to do the work that won him a Nobel prize. All three countries can justifiably claim this great scientist as their own. Ernest Rutherford is one of the most illustrious scientists that the world has ever seen. He achieved enduring international fame because of an incredibly productive life, during which he altered our view of nature on three separate occasions. Combining brilliantly conceived experiments with much hard work and special insight, he explained the perplexing problem of naturally occurring radioactivity, determined the structure of the atom, and was the world's first successful alchemist, changing nitrogen into oxygen. Rutherford received a Nobel prize for the first discovery, but the other two would have been equally worthy candidates, had they been discovered by someone else. Indeed, any one of his other secondary achievements many of which are now almost forgotten would have been enough to bring fame to a lesser scientist. For example, he invented an electrical method for detecting individual ionizing radiations, he dated the age of the Earth, and briefly held the world record for the distance over which wireless waves could be detected. He predicted the existence of neutrons, he oversaw the development of large-scale particle accelerators, and, during the First World War, he led the allied research into the detection of submarines. In this article the author describes the life and times of Ernest Rutherford. (UK)

A Rutherford Scattering Simulation with Microcomputer Graphics.

Science.gov (United States)

Calle, Carlos I.; Wright, Lavonia F.

1989-01-01

Lists a program for a simulation of Rutherford's gold foil experiment in BASIC for both Apple II and IBM compatible computers. Compares Rutherford's model of the atom with Thompson's plum pudding model of the atom. (MVL)

High energy backscattering analysis using RUMP

International Nuclear Information System (INIS)

Doolittle, L.R.

1990-01-01

A backscattering analysis program such as RUMP fundamentally requires two reference sets of data in order to accomplish anything useful: stopping powers and scattering cross sections. Users of original versions of RUMP had to be satisfied with polynomial stopping powers geared for 1 to 3 MeV, and purely Rutherford scattering cross sections. As people increasingly turn to high beam energies to solve difficult materials analysis problems, RUMP has evolved greater flexibility for its reference data. It now allows data files to be loaded describing different stopping powers and arbitrary scattering cross sections. Auxiliary programs have been written to generate the reference data files, either from a theory or from measured reference data. Descriptions are given of both the underlying physics and the operational details of the software

Channeling experiments at IPNE Cyclotron

Energy Technology Data Exchange (ETDEWEB)

Constantin, F; Dumitru, M; Ivan, A [Cyclotron Laboratory, Institute of Atomic Physics, Institute of Physics and Nuclear Engineering, R-76900 Bucharest, P.O.Box MG-6, (Romania)

1992-01-01

Channeling experiments have been performed at the I.P.N.E Cyclotron using a 3 MeV alpha beam. A slide system cut the beam up to 5 minutes spatial resolution with a maximum 60 nA beam current on the target. The two-axis goniometer, fully computer-controlled, moves the target, a silicon wafer, with 2.5 minute resolution, while an alpha particle sensitive solid state detector, monitors the backscattered particle fluence. In the first stage, channeling appears to be a simple, fast and reliable method for precise monocrystal orientation. A reduction of the host yield by a factor of two allowed impurities and defects to be studied. (Author).

Backscattering analysis of AuGe-Ni ohmic contacts of n-GaAs

International Nuclear Information System (INIS)

Nassibian, A.G.; Kalkur, T.S.; Sutherland, G.J.; Cohen, D.

1985-01-01

AuGe-Ni is widely used for the fabrication of ohmic contacts to n-GaAs. The alloying behaviour of evaporated AuGe-Ni alloyed by furnace and Scanning Electron Beam, is characterised by Rutherford backscattering with 2MeV 4 He ions. Since the formation of alloyed AuGe-Ni contacts involves redistribution and diffusion of Ga, As, Ni, Ge and Au, it is difficult to separate the corresponding yields due to gold, Ga As, Ni and Ge in the spectrum. The technique used in the investigation involves assumption of depth distribution of elements and computing the resultant spectrum

Application of the particle backscattering methods for the study of new oxide protective coatings at the surface of Al and Mg alloys

International Nuclear Information System (INIS)

Apelfeld, A.V.; Bespalova, O.V.; Borisov, A.M.; Dunkin, O.N.; Goryaga, N.G.; Kulikauskas, V.S.; Romanovsky, E.A.; Semenov, S.V.; Souminov, I.V.

2000-01-01

Rutherford (1.5 MeV 4 He + ) and Nuclear (7.7 MeV H + ) Backscattering Spectrometry were used for investigation of oxide protective coatings on the surface of Al and Mg alloys obtained by microarc oxidation (MAO). A model of microarc coating formation is proposed. For Mg alloy, the structure of MAO coating with very high corrosion resistance was determined

Rutherford and Bohr*

Indian Academy of Sciences (India)

IAS Admin

He was always concerned about hurting any person's feelings, and he found great ... classical picture might be modified by using Planck's quantum of action. A first manuscript .... problem soon was made academic by Rutherford moving to Cambridge. ..... I hope it will not have too much of a reaction on them'. And later: 'I am ...

The Rutherford Appleton Laboratory's Mark I multiwire proportional counter positron camera

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Tappern, G.J.; Flesher, A.C.

1984-01-01

A small (30 cmx30 cm) model of a proposed large aperture positron camera has been developed at Rutherford Appleton Laboratory. Based on multiwire proportional counter technology, it uses lead foil cathodes which function simultaneously as converters for the 511 keV gamma rays and readout electrodes for a delay line readout system. The detectors have been built up into a portable imaging system complete with a dedicated computer for data taking, processing and display. This has permitted evaluation of this type of positron imaging system in the clinical environment using both cyclotron generated isotopes ( 15 O, 11 C, 18 F, 124 I) and available isotopic generator systems ( 82 Rb, 68 Ga). AT RAL we provided a complete hardware system and sufficient software to permit our hospital based colleagues to generate useful images with the minimum of effort. A complete description of the system is given with performance figures and some of the images obtained in three hospital visits are presented. Some detailed studies of the imaging performance of the positron camera are reported which have bearing on the design of future, improved systems. (orig.)

Detailed analysis of the resonant backscattering spectrum for deeply penetrating protons in carbon

International Nuclear Information System (INIS)

Tosaki, Mitsuo; Ito, Shin; Maeda, Nobuhiro

2000-01-01

In order to study the spectral response in Rutherford backscattering spectroscopy (RBS) for deeply penetrating ions in matter, the resonant backscattering spectra for 5.05-, 5.5- and 6.0-MeV proton incidence on solid carbon material have been measured at a scattering angle of 179.2 deg. (in lab.). Prominent peaks resulting from the sharp 4.8-MeV resonance in 12 C(p,p) 12 C nuclear elastic scattering are observed, even for a penetration depth of 79 μm. Detailed numerical calculations based on an algorithm of straightforward step-by-step evaluation have been made to simulate the observed spectra. The algorithm enables one to rigorously treat both the effect of sharp resonance structure and that of energy-dependent energy loss. Calculations with the SIMNRA code are also made. Through comparison of these calculations with the measured results, some conclusions on the two effects above are presented. In addition, it is demonstrated that the peak profile due to a sharp resonance is very sensitive to the degree of energy straggling

Extracting electron backscattering coefficients from backscattered electron micrographs

International Nuclear Information System (INIS)

Zupanic, F.

2010-01-01

Electron backscattering micrographs possess the so-called Z-contrast, carrying information about the chemical compositions of phases present in microstructures. The intensity at a particular point in the backscattered electron micrograph is proportional to the signal detected at a corresponding point in the scan raster, which is, in turn, proportional to the electron backscattering coefficient of a phase at that point. This article introduces a simple method for extracting the electron backscattering coefficients of phases present in the microstructure, from the backscattered electron micrographs. This method is able to convert the micrograph's greyscale to the backscattering-coefficient-scale. The prerequisite involves the known backscattering coefficients for two phases in the micrograph. In this way, backscattering coefficients of other phases can be determined. The method is unable to determine the chemical compositions of phases or the presence of an element only from analysing the backscattered electron micrograph. Nevertheless, this method was found to be very powerful when combined with energy dispersive spectroscopy, and the calculations of backscattering coefficients. - Research Highlights: →A simple method for extracting the electron backscattering coefficients →The prerequisite is known backscattering coefficients for two phases →The information is complementary to the EDS-results. →This method is especially useful when a phase contains a light element (H, Li, Be, and B)

Traffic modifications on Routes Rutherford, Democrite and Fermi

CERN Multimedia

2015-01-01

The GS Department would like to inform you that until the end of December, the construction of Building 245 will result in the following traffic modifications: Traffic on Route Rutherford will be partially restricted in front of the construction site, Traffic on Route Democrite will be one-way towards Route Rutherford. Also, please note that due to construction work in front of Building 377, Route Fermi will be closed from Wednesday, 10 June until Friday, 7 August. Thank you for your understanding.

Traffic modifications on Routes Rutherford, Democrite and Fermi

CERN Multimedia

2015-01-01

The GS Department would like to inform you that, until the end of December, the construction of Building 245 will result in the following traffic modifications: Traffic on Route Rutherford will be partially restricted in front of the construction site, Traffic on Route Democrite will be one-way towards Route Rutherford. Also, please note that due to construction work in front of Building 377, Route Fermi will be closed from Wednesday, 10 June until Friday, 7 August. Thank you for your understanding.

Quench tests and FEM analysis of Nb3Al Rutherford cables and small racetrack magnets

International Nuclear Information System (INIS)

Yamada, R.; Kikuchi, A.; Chlachidze, G.; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Kashikin, V.V.; Kotelnikov, S.; Lamm, M.; Novitski, I.

2008-01-01

In collaboration between NIMS and Fermilab, we have made copper stabilized Nb 3 Al Rutherford cables, using Nb-matrixed and Ta-matrixed strands. First these cables were investigated at high current in low self field using a flux pump. Using these Rutherford cables, we built and tested small racetrack magnets. The magnet made with the Nb-matrixed strand showed the flux jump instability in low field. The small racetrack magnet wound with the Ta-matrixed Nb 3 Al Rutherford cable was very stable at 4.5 K operation without any instability, as well as at 2.2 K operation. With the successful operation of the small racetrack magnet up to its short sample data, the feasibility of the Nb 3 Al strand and its Rutherford cable for their application to high field magnets is established. The characteristics of Nb 3 Al Rutherford cable is compared with that of the Nb 3 Sn Rutherford cable and the advantages of Nb 3 Al Rutherford cable are discussed

Plasma cleaning and analysis of archeological artefacts from Sipán

Science.gov (United States)

Saettone, E. A. O.; da Matta, J. A. S.; Alva, W.; Chubaci, J. F. O.; Fantini, M. C. A.; Galvão, R. M. O.; Kiyohara, P.; Tabacniks, M. H.

2003-04-01

A novel procedure using plasma sputtering in an electron-cyclotron-resonance device has been applied to clean archeological MOCHE artefacts, unearthed at the Royal Tombs of Sipán. After successful cleaning, the pieces were analysed by a variety of complementary techniques, namely proton-induced x-ray emission, Rutherford backscattering spectroscopy, x-ray diffraction, electron microscopy, and inductively coupled plasma mass spectroscopy. With these techniques, it has been possible to not only determine the profiles of the gold and silver surface layers, but also to detect elements that may be relevant to explain the gilding techniques skillfully developed by the metal smiths of the MOCHE culture.

Plasma cleaning and analysis of archeological artefacts from Sipan

Energy Technology Data Exchange (ETDEWEB)

Saettone, E A O [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Matta, J A S da [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Alva, W [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Chubaci, J F O [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Fantini, M C A [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Galvao, R M O [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Kiyohara, P [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Tabacniks, M H [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil)

2003-04-07

A novel procedure using plasma sputtering in an electron-cyclotron-resonance device has been applied to clean archeological MOCHE artefacts, unearthed at the Royal Tombs of Sipan. After successful cleaning, the pieces were analysed by a variety of complementary techniques, namely proton-induced x-ray emission, Rutherford backscattering spectroscopy, x-ray diffraction, electron microscopy, and inductively coupled plasma mass spectroscopy. With these techniques, it has been possible to not only determine the profiles of the gold and silver surface layers, but also to detect elements that may be relevant to explain the gilding techniques skillfully developed by the metal smiths of the MOCHE culture.

Applications of Nuclear Reaction Analysis for Semiconductor Industry

International Nuclear Information System (INIS)

Wei Luncun

2003-01-01

Many thin film samples used in the semiconductor industry contain C, N and O. The detection limits and accuracy obtained by Rutherford Backscattering Spectroscopy (RBS) measurement are limited due to the small cross section values. High energy non-Rutherford backscattering is often used to enhance the sensitivities. But non-Rutherford cross section values are irregular and can not be calculated as normal Rutherford backscattering values. It is also difficult to find an appropriate energy window that for all these elements, and high-energy ions are needed. In this paper, the Nuclear Reaction Analysis (NRA) method is used to simultaneously measure C, N and O. several applications in the semiconductor research, development, and manufacturing areas are presented

Quench tests and FEM analysis of Nb3Al Rutherford cables and small racetrack magnets

Energy Technology Data Exchange (ETDEWEB)

Yamada, R.; Kikuchi, A.; Chlachidze, G.; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Kashikin, V.V.; Kotelnikov, S.; Lamm, M.; Novitski, I.; /Fermilab /Tsukuba Magnet Lab. /KEK, Tsukuba

2008-12-01

In collaboration between NIMS and Fermilab, we have made copper stabilized Nb{sub 3}Al Rutherford cables, using Nb-matrixed and Ta-matrixed strands. First these cables were investigated at high current in low self field using a flux pump. Using these Rutherford cables, we built and tested small racetrack magnets. The magnet made with the Nb-matrixed strand showed the flux jump instability in low field. The small racetrack magnet wound with the Ta-matrixed Nb{sub 3}Al Rutherford cable was very stable at 4.5 K operation without any instability, as well as at 2.2 K operation. With the successful operation of the small racetrack magnet up to its short sample data, the feasibility of the Nb{sub 3}Al strand and its Rutherford cable for their application to high field magnets is established. The characteristics of Nb{sub 3}Al Rutherford cable is compared with that of the Nb{sub 3}Sn Rutherford cable and the advantages of Nb{sub 3}Al Rutherford cable are discussed.

The analysis of Rutherford scattering-channelling measurements of disorder production and annealing in ion irradiated semiconductors

International Nuclear Information System (INIS)

Carter, G.; Elliman, R.G.

1983-01-01

Rutherford scattering and channelling of light probe ions (e.g. He + ) has been extensively used for studies of disorder production in ion implanted semiconductors. Various authors have analysed models of amorphousness accumulation and Carter and Webb have indicated the general difficulties in assessing disorder production models from RBS/channelling studies if the production modes are complex and the manner in which the technique responds to different defect structures is unspecified. For less complex disorder production modes and by making reasonable assumptions about the technique response however, some insight into the form of backscattering yield - ion implant fluence functions can be obtained as is discussed in the present communication. It thus becomes possible to infer the importance of different disorder generation processes from RBS/channelling - ion influence studies. It will also be shown how simple annealing processes modify disorder accumulation and thus again how the operation of such processes may be inferred from RBS/channelling - ion fluence measurements. (author)

Compositional analysis of silicon nitride films on Si and GaAs by backscattering spectrometry and nuclear resonance reaction analysis

International Nuclear Information System (INIS)

Kumar, Sanjiv; Raju, V.S.

2004-01-01

This paper describes the application of proton and α-backscattering spectrometry for the determination of atomic ratio of Si to N in 1100-5000 A silicon nitride films on Si and GaAs. The conventional α-Rutherford backscattering spectrometry is suitable for the analysis of films on Si; it is rather inadequate for films on GaAs due to higher background from the substrate. It is shown that these films can be analysed by 14 N(α,α) 14 N scattering with 3.5 MeV α-particles. Proton elastic scattering with enhanced cross sections for 28 Si(p,p) 28 Si and 14 N(p,p) 14 N scatterings, is also suitable for analysing films on GaAs. However, the analysis of films on Si by this technique is difficult due to interferences between the signals of Si from the film and the substrate. In addition, the hydrogen content in films is determined by 1 H( 19 F,αγ) 16 O nuclear reaction analysis using the resonance at 6.4 MeV. The combination of backscattering spectrometry with nuclear reaction analysis provides compositional analysis of ternary Si 1-(x+y) N x H y films

Status report on the folded tandem ion accelerator at BARC

Indian Academy of Sciences (India)

Folded tandem ion accelerator; charged particle beams; voltage stability; Rutherford backscattering; ion optics; beam lines. Abstract. The folded tandem ion accelerator (FOTIA) facility set up at BARC has become operational. At present, it is used for elemental analysis studies using the Rutherford backscattering technique.

The potential of materials analysis by electron Rutherford backscattering as illustrated by a case study of mouse bones and related compounds

International Nuclear Information System (INIS)

Vos, M.; Toekesi, K.; Benkoe, I.

2012-01-01

Complete text of publication follows. Electron Rutherford backscattering (ERBS) has a number of distinct advantages for semi-quantitative analysis of samples. These are for example: a) Its high energy makes it rather insensitive to surface effects. b) The peaks appear well approximated by Gaussian with no obvious problems due to background subtraction. c) All the electrons involved have very similar kinetic energy, and hence one does not need to consider changes of the mean-free path or the analyzer transmission function. d) There are no intrinsic satellites to complicate the quantitative interpretation. On the other hand ERBS has a weak point, peaks tend to overlap. Peak separation is proportional to the incoming energy E0, but the intrinsic peak width increases proportional to the square root of E 0 . In practice one has to live with overlapping peaks. In the present work we mainly focus on the measurement and analysis procedure, and compare our best estimate of the concentration of the various elements in mouse bone with that obtained in a recent paper. The promise of ERBS as an analytical technique is clear from the successful analysis of the simple case of calcium carbonate and the somewhat more complicated case of hydroxyapatite. Here agreement between the measured and actual composition are on a very respectable 10% level. The actual bone sample showed more variation in outcome and a somewhat less satisfactory agreement between experiment and theory (see Fig. 1). The variation in outcome between the different measurements can be due to the fact that we average over very few grains, and that the grain composition will vary somewhat with its original position in the bone. In summary, ERBS can become a useful tool to study bone mineralization. As our knowledge of bone mineralization is incomplete this is currently an active topic of multidisciplinary research involving people working in physics, chemistry and biological/medical sciences. One of the important

Medical Cyclotrons

Science.gov (United States)

Friesel, D. L.; Antaya, T. A.

Particle accelerators were initially developed to address specific scientific research goals, yet they were used for practical applications, particularly medical applications, within a few years of their invention. The cyclotron's potential for producing beams for cancer therapy and medical radioisotope production was realized with the early Lawrence cyclotrons and has continued with their more technically advanced successors — synchrocyclotrons, sector-focused cyclotrons and superconducting cyclotrons. While a variety of other accelerator technologies were developed to achieve today's high energy particles, this article will chronicle the development of one type of accelerator — the cyclotron, and its medical applications. These medical and industrial applications eventually led to the commercial manufacture of both small and large cyclotrons and facilities specifically designed for applications other than scientific research.

COMPLETE SUPPRESSION OF THE m=2/n-1 NEOCLASSICAL TEARING MODE USING ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D

International Nuclear Information System (INIS)

PETTY, CC; LAHAYE, LA; LUCE, TC; HUMPHREYS, DA; HYATT, AW; PRATER, R; STRAIT, EJ; WADE, MR

2003-01-01

A271 COMPLETE SUPPRESSION OF THE M=2/N-1 NEOCLASSICAL TEARING MODE USING ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D. The first suppression of the important and deleterious m=2/n=1 neoclassical tearing mode (NTM) is reported using electron cyclotron current drive (ECCD) to replace the ''missing'' bootstrap current in the island O-point. Experiments on the DIII-D tokamak verify the maximum shrinkage of the m=2/n=1 island occurs when the ECCD location coincides with the q = 2 surface. The DIII-D plasma control system is put into search and suppress mode to make small changes in the toroidal field to find and lock onto the optimum position, based on real time measurements of dB θ /dt, for complete m=2/n=1 NTM suppression by ECCD. The requirements on the ECCD for complete island suppression are well modeled by the modified Rutherford equation for the DIII-D plasma conditions

Earnest Rutherford, the solution

CERN Multimedia

2003-01-01

If you did not make it to the Science & Society talk by John Campbell last week and are still wondering about the spelling of "Earnest", here is the solution: Two months after the birth of his fourth child on 30 August 1871 in Spring Grove, New Zealand, James Rutherford registered his son, who was recorded as "Earnest" in the Birth Register. Presumably the Registrar wrote the name down as it sounded and the father failed to notice the mistake when signing the Register.

Self-consistent modeling of the dynamic evolution of magnetic island growth in the presence of stabilizing electron-cyclotron current drive

International Nuclear Information System (INIS)

Chatziantonaki, Ioanna; Tsironis, Christos; Isliker, Heinz; Vlahos, Loukas

2013-01-01

The most promising technique for the control of neoclassical tearing modes in tokamak experiments is the compensation of the missing bootstrap current with an electron-cyclotron current drive (ECCD). In this frame, the dynamics of magnetic islands has been studied extensively in terms of the modified Rutherford equation (MRE), including the presence of a current drive, either analytically described or computed by numerical methods. In this article, a self-consistent model for the dynamic evolution of the magnetic island and the driven current is derived, which takes into account the island's magnetic topology and its effect on the current drive. The model combines the MRE with a ray-tracing approach to electron-cyclotron wave-propagation and absorption. Numerical results exhibit a decrease in the time required for complete stabilization with respect to the conventional computation (not taking into account the island geometry), which increases by increasing the initial island size and radial misalignment of the deposition. (paper)

Self-consistent modeling of the dynamic evolution of magnetic island growth in the presence of stabilizing electron-cyclotron current drive

Science.gov (United States)

Chatziantonaki, Ioanna; Tsironis, Christos; Isliker, Heinz; Vlahos, Loukas

2013-11-01

The most promising technique for the control of neoclassical tearing modes in tokamak experiments is the compensation of the missing bootstrap current with an electron-cyclotron current drive (ECCD). In this frame, the dynamics of magnetic islands has been studied extensively in terms of the modified Rutherford equation (MRE), including the presence of a current drive, either analytically described or computed by numerical methods. In this article, a self-consistent model for the dynamic evolution of the magnetic island and the driven current is derived, which takes into account the island's magnetic topology and its effect on the current drive. The model combines the MRE with a ray-tracing approach to electron-cyclotron wave-propagation and absorption. Numerical results exhibit a decrease in the time required for complete stabilization with respect to the conventional computation (not taking into account the island geometry), which increases by increasing the initial island size and radial misalignment of the deposition.

Superconducting cyclotrons

International Nuclear Information System (INIS)

Blosser, H.G.; Johnson, D.A.; Burleigh, R.J.

1976-01-01

Superconducting cyclotrons are particularly appropriate for acceleration of heavy ions. A review is given of design features of a superconducting cyclotron with energy 440 (Q 2 /A) MeV. A strong magnetic field (4.6 tesla average) leads to small physical size (extraction radius 65 cm) and low construction costs. Operating costs are also low. The design is based on established technology (from present cyclotrons and from large bubble chambers). Two laboratories (in Chalk River, Canada and in East Lansing, Michigan) are proceeding with construction of full-scale prototype components for such cyclotrons

Scientific work as done at the Rutherford-Appleton laboratory

International Nuclear Information System (INIS)

Ulehla, I.

1983-01-01

The former Rutherford Laboratory founded in 1957 has undergone significant changes. In 1977 the Appleton Laboratory was added. The role of the laboratory in British research is brought out not only by the financial allocations but also by the equipment and staff which now number 1500. At the centre of scientific activity is the physics of elementary particles (high energy physics). In 1982 the laboratory conducted 57 experiments in cooperation with institutions of higher education and other institutions. The Rutherford Laboratory has gained an important position especially in the field of automatic processing of experimental data and in the control and self-control of experiments. (J.P.)

Ernest Rutherford, his genius shaped our modern world

International Nuclear Information System (INIS)

MacGregor Douglas, I.J.

2011-01-01

This paper describes how Rutherford deduced the existence of a dense, highly charged nucleus at the heart of the atom and outlines the enormous impact his work has had on science and society. (author)

Ernest Rutherford, his genius shaped our modern world

Energy Technology Data Exchange (ETDEWEB)

MacGregor Douglas, I.J. [School of Physics and Astronomy, University of Glasgow (United Kingdom)

2011-07-01

This paper describes how Rutherford deduced the existence of a dense, highly charged nucleus at the heart of the atom and outlines the enormous impact his work has had on science and society. (author)

Backscattering of gyrotron radiation and short-wavelength turbulence during electron cyclotron resonance plasma heating in the L-2M stellarator

Energy Technology Data Exchange (ETDEWEB)

Batanov, G. M.; Borzosekov, V. D., E-mail: tinborz@gmail.com; Kovrizhnykh, L. M.; Kolik, L. V.; Konchekov, E. M.; Malakhov, D. V.; Petrov, A. E.; Sarksyan, K. A.; Skvortsova, N. N.; Stepakhin, V. D.; Kharchev, N. K. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

2013-06-15

Backscattering of gyrotron radiation ({theta} = {pi}) by short-wavelength density fluctuations (k{sub Up-Tack} = 30 cm{sup -1}) in the plasma of the L-2M stellarator was studied under conditions of electron cyclotron resonance (ECR) plasma heating at the second harmonic of the electron gyrofrequency (75 GHz). The scattering of the O-wave emerging due to the splitting of the linearly polarized gyrotron radiation into the X- and O-waves was analyzed. The signal obtained after homodyne detection of scattered radiation is a result of interference of the reference signal, the quasi-steady component, and the fast oscillating component. The coefficients of reflection of the quasi-steady component, R{sub =}{sup 2}(Y), and fast oscillating component, R{sub {approx}}{sup 2}(Y), of scattered radiation are estimated. The growth of the R{sub {approx}}{sup 2}(Y) coefficient from 3.7 Multiplication-Sign 10{sup -4} to 5.2 Multiplication-Sign 10{sup -4} with increasing ECR heating power from 190 to 430 kW is found to correlate with the decrease in the energy lifetime from 1.9 to 1.46 ms. The relative density of short-wavelength fluctuations is estimated to be Left-Pointing-Angle-Bracket n{sub {approx}}{sup 2} Right-Pointing-Angle-Bracket / Left-Pointing-Angle-Bracket n{sub e}{sup 2} Right-Pointing-Angle-Bracket = 3 Multiplication-Sign 10{sup -7}. It is shown that the frequencies of short-wavelength fluctuations are in the range 10-150 kHz. The recorded short-wavelength fluctuations can be interpreted as structural turbulence, the energy of which comprises {approx}10% of the total fluctuations energy. Simulations of transport processes show that neoclassical heat fluxes are much smaller than anomalous ones. It is suggested that short-wavelength turbulence plays a decisive role in the anomalous heat transport.

Rutherford Appleton Laboratory

International Nuclear Information System (INIS)

1993-01-01

Rutherford Appleton Laboratory (RAL), described in this document, supports a wide variety of projects. Each year more than 1000 scientists and engineers visit RAL to use its world-class laser and neutron-scattering facilities. RAL staff design and build instruments which circle the Earth in satellites, increasing our understanding of ozone depletion and global warming, of the life cycles of stars and galaxies and, indeed, of the origin of the Universe itself. They work with their academic colleagues at international laboratories such as European Organization for Nuclear Research (CERN), Geneva, where massive underground machines probe the microstructure of the atomic nucleus. Vastly complex calculations are carried out on the design of anti-cancer drugs, for example, using supercomputers at RAL. (author)

Vancouver Cyclotron Conference

International Nuclear Information System (INIS)

Clark, David J.

1993-01-01

Although no longer on the high energy frontier, the cyclotron field is still a major scientific growth area. Its progress is highlighted at the international conference on cyclotron design, development and utilization held at intervals of about three years, under the auspices of the International Union of Pure and Applied Physics (IUPAP). Vancouver, surrounded by mountains, water and some cyclotrons, provided a pleasant setting for the 13th Conference, held last summer. With over 200 cyclotrons in operation around the world, the attendance, 241 delegates and 26 industrial exhibitors, was a near record, reflecting the flourishing state of the field. The early sessions covered the initial operation of new or upgraded cyclotron facilities. Major facilities completed since the previous Conference in Berlin in May 1989 included the 400 MeV ring cyclotron at Osaka, the U400M cyclotron at Dubna which will be coupled to the U400 to give 20 MeV nucléon uranium beams, the 130 MeV cyclotron at Jyvaskyla (in Finland, the furthest north!), the 110 MeV JAERI machine in Japan, and the 65 MeV proton therapy cyclotron in Nice. Among the facility upgrades were the KFA cyclotron at Julich which will inject the 2.5 GeV storage ring COSY, and the addition of an FM mode to the K=200 CW mode at Uppsala to give protons up to 180 MeV. The impressive current of 1.5 mA at 72 MeV obtained from the PSI Injector II will soon be injected into the 590 MeV ring

Sputtering Yields of Si and Ni from the Ni1-xSix System Studied by Rutherford Backscattering Spectrometry

Science.gov (United States)

Kim, Su Chol; Yamaguchi, Satoru; Kataoka, Yoshihide; Iwami, Motohiro; Hiraki, Akio; Satou, Mamoru; Fujimoto, Fuminori

1982-01-01

Sputtering yields of Si and Ni from thin layer films of Ni-Si compounds (Ni1-xSix), including the pure materials (Ni and Si), caused by 5 keV Ar+ ion bombardment were investigated using backscattering spectrometry. The sputtering yield for Si from Ni1-xSix increased with increasing Si concentration. However, there is an abrupt decrease in the yield for Si concentrations above NiSi2 to pure Si. This is in clear contrast to the sputtering yield of Ni from Ni1-xSix which increased with increasing Ni concentration monotonously. These results are discussed on the basis of both the difference in the atomic density and the electronic state of the alloy.

Rutherford, Maestro of the Atom

International Nuclear Information System (INIS)

Campbell, John

2003-01-01

This talk will cover some of the lesser known aspects of Rutherford's work, including his early work in wireless signaling and his later encouragement of radio studies of the ionosphere, the development of what was later improved to be now called the Geiger-Muller tube, his acoustic work for submarine detection during the First World War, the development of particle accelerators and the race to splitting the atom, the first use of coincidence detectors, and why he received just one Nobel Prize.

Photonic Rutherford scattering: A classical and quantum mechanical analogy in ray and wave optics

Science.gov (United States)

Selmke, Markus; Cichos, Frank

2013-06-01

Using Fermat's least-optical-path principle, the family of ray trajectories through a special (but common) type of a gradient refractive index lens n(r)=n0+ΔnR /r is solved analytically. The solution gives a ray equation r(ϕ) that is closely related to Rutherford scattering trajectories; we therefore refer to this refraction process as "photonic Rutherford scattering." It is shown that not only do the classical limits correspond but also the wave-mechanical pictures coincide—the time-independent Schrödingier equation and the Helmholtz equation permit the same mapping between the scattering of massive particles and optical scalar waves. Scattering of narrow beams of light finally recovers the classical trajectories. The analysis suggests that photothermal single-particle microscopy measures photonic Rutherford scattering in specific limits and allows for an individual single-scatterer probing. A macroscopic experiment is demonstrated to directly measure the scattering angle to impact parameter relation, which is otherwise accessible only indirectly in Rutherford-scattering experiments.

MICHIGAN: Cyclotron conference

Energy Technology Data Exchange (ETDEWEB)

Anon.

1984-10-15

A sense of excitement was in the air as cyclotron physicists and engineers from 17 countries convened on 30 April for the opening of the Tenth International Conference on Cyclotrons and Their Applications. Some 50 years after its invention, the redoubtable cyclotron remains a topic of compelling current interest. Cyclotron experts gathered at Michigan State University's Kellogg Center to hear of latest developments, of progress and successes on new machines which had come into operation, of new projects which were underway, and of dreams which lay ahead.

RUTHERFORD APPLETON: What's in a name?!

International Nuclear Information System (INIS)

Anon.

1995-01-01

Full text: The initials 'RAU are well known in the world of particle physics, but recently the official name of the Laboratory has undergone several transmogrifications. To further complicate matters, the funding body for Particle Physics within the UK has changed too! On 1 April 1994 the Rutherford Appleton Laboratory combined with the Daresbury Laboratory to become a combined laboratory known as the Daresbury and Rutherford Appleton Laboratories (DRAL). At the same time the old Science and Engineering Research Council (SERC) was wound up, and funding was channelled through the newly formed Particle Physics and Astronomy Research Council (PPARC). Also, and just for an interim period, DRAL became part of the new Engineering and Physical Sciences Research Council (EPSRC). One year later a more profound change occurred when DRAL became a Research Council in its own right, and the legal entity created by Royal Charter was named The Council for the Central Laboratory of the Research Councils', abbreviated to CCLRC. On 1 April 1995, DRAL became The Central Laboratory of the Research Councils', and the abbreviation CLRC may be used. In spite of the changes to the official name, the laboratory sited at Chilton, The DAPNIA (Saclay, France) and Argonne transportable polarized target used in 1989- 1990 for a Fermi lab experiment has been used in a new experiment at Dubna. Gilles Durand from DAPNIA (right) and Yuri Usov of Dubna's Joint Institute for Nuclear Research (JINR) were responsible for construction. Oxfordshire, will continue to be known as the Rutherford Appleton Laboratory, or RAL

Guide to the Durham-Rutherford high energy physics databases

International Nuclear Information System (INIS)

Gault, F.D.; Lotts, A.P.; Read, B.J.; Crawford, R.L.; Roberts, R.G.

1979-12-01

New databases and graphics facilities are added in this edition of the guide. It explains, with examples, how to retrieve tabulated experimental scattering data from databases on the Rutherford Laboratory computer network. (author)

Electromagnetic cyclotron harmonic waves

International Nuclear Information System (INIS)

Ohnuma, T.; Watanabe, T.; Hamamatsu, K.

1981-09-01

Electromagnetic electron cyclotron harmonic waves just below the electron cyclotron harmonics are investigated numerically and experimentally. Backward waves which are observed to propagate nearly perpendicular to the magnetic field just below the electron cyclotron frequency in a high density magnetoplasma are confirmed to be in accord with the theoretical electromagnetic cyclotron waves. (author)

MICHIGAN: Cyclotron conference

International Nuclear Information System (INIS)

Anon.

1984-01-01

A sense of excitement was in the air as cyclotron physicists and engineers from 17 countries convened on 30 April for the opening of the Tenth International Conference on Cyclotrons and Their Applications. Some 50 years after its invention, the redoubtable cyclotron remains a topic of compelling current interest. Cyclotron experts gathered at Michigan State University's Kellogg Center to hear of latest developments, of progress and successes on new machines which had come into operation, of new projects which were underway, and of dreams which lay ahead

Analysis of Nb$_{3}$Sn Rutherford cable production and strand deformations

CERN Document Server

Peggiani, Sonia; Beghi, Marco

The development of cutting-edge 11-12 T superconducting magnets made from Nb$_{3}$Sn technology is one of the major milestones for the upgrade of the Large Hadron Collider at CERN. The upgrade, called High Luminosity LHC Project, was planned in order to reach higher luminosity and discover new particles. Replacing the NbTi superconductor with the Nb$_{3}$Sn makes it possible to reach a practical operating magnetic field limit of up to 16 T. The superconducting coils are formed by Nb$_{3}$Sn Rutherford cables with a trapezoidal cross section and composed of 40 strands. Since the superconducting phase of Nb$_{3}$Sn is very brittle and it is reached after a thermal cycle, the Nb$_{3}$Sn Rutherford cable needs to be wound in a coil before the thermal treatment. The cabling process is a delicate step in the production of high performing cables that need different systems to control their quality. This work aims to provide practical tools to analyze the Nb$_{3}$Sn Rutherford cable production and the strands defo...

Cyclotron waves in plasma

CERN Document Server

Lominadze, D G

2013-01-01

Cyclotron Waves in Plasma is a four-chapter text that covers the basic physical concepts of the theory of cyclotron waves and cyclotron instabilities, brought about by the existence of steady or alternating plasma currents flowing perpendicular to the magnetic field.This book considers first a wide range of questions associated with the linear theory of cyclotron oscillations in equilibrium plasmas and in electron plasmas in metals and semiconductors. The next chapter deals with the parametric excitation of electron cyclotron oscillations in plasma in an alternating electric field. A chapter f

Cyclotron waves in plasma

International Nuclear Information System (INIS)

Lominadse, D.G.

1975-01-01

The book deals with fundamental physical concepts of the theory of cyclotron waves and cyclotron instabilities conditioned by the presence in plasma of direct or alternating electric currents passing in it perpendicularily to a magnetic field. A great variety of problems is considered connected with the linear theory of cyclotron oscillations in equilibrium and electron plasma of metals and semiconductors. Parametric excitations of electron cyclotron oscillations of plasma in an alternating electric field are studied. Particular attention is paid to the investigation of plasma turbulence arising as a result of development of cyclotron instabilities. Experimental data are discussed and compared with theoretical results

Cyclotrons: 1978

International Nuclear Information System (INIS)

Martin, J.A.

1978-01-01

A compilation is presented of the experimental facilities of the world's cyclotrons including history and status, staff and operation, research staff, target facilities, magnet, acceleration system, vacuum system, characteristic beams, beam properties, and a plan view of the facility for each cyclotron

Contribution of Rutherford backscattering spectrometry to the study of irradiation effects on diffusion properties in oxides glasses

International Nuclear Information System (INIS)

Calmon, P.

1990-10-01

We have studied the impurity diffusion of heavy elements (lead, uranium) in soda lime silicate glasses under irradiation with ions (He + 1000 KeV,Ar + 250-500 KeV), with gamma rays (1.17-1.33 MeV) and with X-rays (40-60 KeV). RF sputtering and ionic implantation methods have been used for the diffusion target preparation. A comparison of these technics reveals ionic implantation as the most suitable method. For the analysis of profiles the backscattering spectrometry has been used. RBS simulation programs have been developed in order to treat some complex situations like lateral inhomogeneities and composition changes of the sample. Enhanced diffusion and occasionally precipitation have been observed under ions irradiation for lead, while uranium was more diffusing under gamma rays irradiations. On the contrary no X-rays effect have been noted. Our results show that network modifiers impurities diffusion (in our case lead) are generally controlled by sodium redistributions. The radiation damages are not negligible and electronic excitations play a dominant role [fr

Ion backscattering and X-ray investigations of violin varnish and wood

International Nuclear Information System (INIS)

Sigurd, D.; Tove, P.A.; Petersson, S.

1980-01-01

The use of Rutherford backscattering (RBS) of ions (i.e. α-particles) and excitation of characteristic X-rays by protons, for determining the elemental composition of the top layers of violin varnish and wood is described. The amount of elements such as C, O, Si, S, Ca, Cu, Fe, Ni, Zn, Pb has been measured, on the varnished and unvarnished sides of wood samples from old instrument makers such as A. Stradivari, G. Guarneri del Gesu, Santo Serafin, C. Tononi etc. Differences in both the shape of the RBS spectra and in the presence of different elements are found and discussed. The use of X-ray excitation by ions (i.e. protons) helps in assessing the presence of the different elements. X-ray investigations can be done with instruments in air while RBS (at least in the presently used form) has to be performed in a vacuum chamber. Apart from offering an aid in determining the materials and procedures which were used in fabricating acoustically excellent instruments, the method could be of value for identifying their authenticity. (orig.)

Ion backscattering and x-ray investigations of violin varnish and wood

Science.gov (United States)

Arne Tove, Per; Sigurd, Dag; Petersson, Sture

1980-01-01

The use of Rutherford backscattering (RBS) of ions (i.e. α-particles) and excitation of characteristic X-rays by protons, for determining the elemental composition of the top layers of violin varnish and wood is described. The amount of elements such as C, O, Si, S, Ca, Cu, Fe, Ni, Zn, Pb has been measured, on the varnished and unvarnished sides of wood samples from old instrument makers such as A. Stradivari, G. Guarneri del Gesu, Santo Serafin, C. Tononi etc. Differences in both the shape of the RBS spectra and in the presence of different elements are found and discussed. The use of X-ray excitation by ions (i.e. protons) helps in assessing the presence of the different elements. X-ray investigations can be done with instruments in air while RBS (at least in the presently used form) has to be performed in a vacuum chamber. Apart from offering an aid in determining the materials and procedures which were used in fabricating acoustically excellent instruments, the method could be of value for identifying their authenticity.

Nonlinear excitation of electron cyclotron waves by a monochromatic strong microwave: computer simulation analysis of the MINIX results

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, H.; Kimura, T.

1986-01-01

Triggered by the experimental results of the MINIX, a computer simulation study was initiated on the nonlinear excitation of electrostatic electron cyclotron waves by a monochromatic electromagnetic wave such as the transmitted microwave in the MINIX. The model used assumes that both of the excited waves and exciting (pumping) electromagnetic wave as well as the idler electromagnetic wave propagate in the direction perpendicular to the external magnetic field. The simulation code used for this study was the one-and-two-half dimensional electromagnetic particle code named KEMPO. The simulation result shows the high power electromagnetic wave produces both the backscattered electromagnetic wave and electrostatic electron cyclotron waves as a result of nonlinear parametric instability. Detailed nonlinear microphysics related to the wave excitation is discussed in terms of the nonlinear wave-wave couplings and associated ponderomotive force produced by the high power electromagnetic waves. 2 references, 4 figures.

Nonlinear excitation of electron cyclotron waves by a monochromatic strong microwave: computer simulation analysis of the MINIX results

International Nuclear Information System (INIS)

Matsumoto, H.; Kimura, T.

1986-01-01

Triggered by the experimental results of the MINIX, a computer simulation study was initiated on the nonlinear excitation of electrostatic electron cyclotron waves by a monochromatic electromagnetic wave such as the transmitted microwave in the MINIX. The model used assumes that both of the excited waves and exciting (pumping) electromagnetic wave as well as the idler electromagnetic wave propagate in the direction perpendicular to the external magnetic field. The simulation code used for this study was the one-and-two-half dimensional electromagnetic particle code named KEMPO. The simulation result shows the high power electromagnetic wave produces both the backscattered electromagnetic wave and electrostatic electron cyclotron waves as a result of nonlinear parametric instability. Detailed nonlinear microphysics related to the wave excitation is discussed in terms of the nonlinear wave-wave couplings and associated ponderomotive force produced by the high power electromagnetic waves. 2 references, 4 figures

Cyclotrons as mass spectrometers

International Nuclear Information System (INIS)

Clark, D.J.

1984-04-01

The principles and design choices for cyclotrons as mass spectrometers are described. They are illustrated by examples of cyclotrons developed by various groups for this purpose. The use of present high energy cyclotrons for mass spectrometry is also described. 28 references, 12 figures

Medical applications of cyclotrons

International Nuclear Information System (INIS)

Jean, R.; Fauchet, M.

1978-01-01

Isochronous cyclotrons used to accelerate different charged particles (protons, deuterons, alphas...) at variable energies, have important medical applications, for neutron teletherapy, in vivo or in vitro activation analysis or production of short-lived radioisotopes for nuclear medicine. The characteristics of the cyclotron presently available are described for these three applications (low energy 'compact' cyclotrons, cyclotrons of intermediate and high energies), and their advantages are discussed from the points of view of the medical requirements, the financial investments and the results obtained. (orig.) [de

Science & Society: The search for the real Earnest Rutherford*

CERN Multimedia

2003-01-01

Every physicist knows the name Rutherford who radically altered our understanding of nature on three separate occasions. Through brilliantly conceived experiments, and with special insight, he explained the perplexing problem of radioactivity as the spontaneous disintegration of atoms (they were not necessarily stable entities as had been assumed since the time of the ancient Greeks), he determined the structure of the atom and he was the world's first successful alchemist (he converted nitrogen into oxygen). This talk given by John Campbell, however, will cover some of the lesser known aspects of Rutherford's work, including his early wireless signalling, development of what was later improved to be now called the Geiger-Muller tube, his acoustic work for submarine detection during the First World War, the development of particle accelerators and the race to use them, the first use of a coincidence detector, and why he received just one Nobel Prize. Dr Campbell, a condensed matter physicist at the Universi...

Electromagnetic backscattering from one-dimensional drifting fractal sea surface II: Electromagnetic backscattering model

International Nuclear Information System (INIS)

Xie Tao; Zhao Shang-Zhuo; Fang He; Yu Wen-Jin; He Yi-Jun; Perrie, William

2016-01-01

Sea surface current has a significant influence on electromagnetic (EM) backscattering signals and may constitute a dominant synthetic aperture radar (SAR) imaging mechanism. An effective EM backscattering model for a one-dimensional drifting fractal sea surface is presented in this paper. This model is used to simulate EM backscattering signals from the drifting sea surface. Numerical results show that ocean currents have a significant influence on EM backscattering signals from the sea surface. The normalized radar cross section (NRCS) discrepancies between the model for a coupled wave-current fractal sea surface and the model for an uncoupled fractal sea surface increase with the increase of incidence angle, as well as with increasing ocean currents. Ocean currents that are parallel to the direction of the wave can weaken the EM backscattering signal intensity, while the EM backscattering signal is intensified by ocean currents propagating oppositely to the wave direction. The model presented in this paper can be used to study the SAR imaging mechanism for a drifting sea surface. (paper)

Design, processing, and properties of Bi 2212\\/Ag Rutherford cables

CERN Document Server

Collings, E W; Scanlan, R M; Dietderich, D R; Motowidlo, L R; Sokolowski, R S; Aoki, Y; Hasegawa, T

1999-01-01

In a program intended to explore the use of high temperature superconducting (HTSC) cables in high field synchrotron dipole magnets model Bi:2212/Ag Rutherford cables were designed bearing in mind the needs for mechanical integrity, relatively high tensile strength, and low coupling losses. To satisfy these needs a core-type cable design was selected and a readily available heat-resistant core material acquired. Cables were wound for critical current- and AC loss measurement. Both winding-induced (mechanical) and core-induced (chemical) critical current degradation was examined. Interstrand coupling loss was measured calorimetrically on model cable samples with bare- and oxide-coated cores. From the results it was predicted that the losses of full-scale Bi:2212/Ag-wound LHC-type Rutherford cables would fall close to the acceptability range for the windings of high-field accelerator dipoles. (10 refs).

Stabilization of neoclassical tearing modes by electron cyclotron current drive in JT-60U

International Nuclear Information System (INIS)

Isayama, A.; Oyama, N.; Urano, H.; Suzuki, T.; Takechi, M.; Hayashi, N.; Nagasaki, K.; Kamada, Y.; Ide, S.; Ozeki, T.

2007-01-01

Results of active control of neoclassical tearing modes (NTMs) by electron cyclotron current drive (ECCD) in JT-60U are described. Growth of an NTM with poloidal mode number m = 3 and toroidal mode number n = 2 has been suppressed by ECCD inside the sawtooth inversion radius in the co-direction, showing the possibility of the coexistence of sawtooth oscillations and a small-amplitude m/n = 3/2 NTM without large confinement degradation. Stabilization of an m/n = 2/1 NTM by ECCD at the mode rational surface has been demonstrated with a small ratio of the current density driven by the electron cyclotron (EC) wave to the local bootstrap current density (∼ 0.5). In addition, dependence of the stabilization effect on ECCD location has been investigated in detail. It has been found that an m/n = 2/1 NTM can be completely stabilized with the misalignment of the ECCD location less than about half of the full island width, and that the m/n = 2/1 NTM is destabilized with the misalignment comparable to the full island width. Time-dependent, self-consistent simulation of magnetic island evolution using the TOPICS code has shown that the stabilization and destabilization of an m/n = 2/1 NTM are well reproduced with the same set of coefficients of the modified Rutherford equation. The TOPICS simulation has also clarified that EC wave power required for complete stabilization can be significantly reduced by narrowing the ECCD deposition width

Dynamic coherent backscattering mirror

Energy Technology Data Exchange (ETDEWEB)

Zeylikovich, I.; Xu, M., E-mail: mxu@fairfield.edu [Physics Department, Fairfield University, Fairfield, CT 06824 (United States)

2016-02-15

The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the direction space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the spatial space. The random medium behaves as a reciprocity mirror which robustly converts a diverging incident beam into a converging backscattering one focusing at a conjugate spot in space. Here we first analyze theoretically this coherent backscattering mirror (CBM) phenomenon and then demonstrate the capability of CBM compensating and correcting both static and dynamic phase distortions occurring along the optical path. CBM may offer novel approaches for high speed dynamic phase corrections in optical systems and find applications in sensing and navigation.

Beat-wave accelerator studies at the Rutherford Appleton Laboratory

International Nuclear Information System (INIS)

Lawson, J.D.

1985-01-01

The study carried out in 1982-83 at the Rutherford Appleton Laboratory to examine how one might use the beat-wave principle to construct a useful high energy accelerator is reviewed, and comments are made on later developments. A number of problems are evident to which solutions cannot at present be foreseen. (author)

High-energy helium backscattering for the compositional analysis of thin-film oxide-superconductors

International Nuclear Information System (INIS)

Hubbard, K.M.; Martin, J.A.; Muenchausen, R.E.; Tesmer, J.R.; Nastasi, M.

1989-01-01

Recent experiments have demonstrated that the broad elastic-scattering resonance for 8.8 MeV helium bombardment of oxygen can be exploited to measure the oxygen content of YBaCuO thin films. A potential difficulty with such measurements is distortion of the backscattering spectrum due to resonant scattering from the substrate elements, which could prevent the accurate integration of peak areas. We have measured the elastic scattering cross sections for Sr and Ti, relative to Gd, with He ions in the energy range of 2.2--8.8 MeV, and a scattering angle of 166 degree. The results verify that resonant scattering from the substrate does not interfere with the high-energy compositional analysis of YBaCuO films deposited on SrTiO 3 . Scattering cross sections for Ca, measured relative to Ba, have also been determined for application to the analysis of BiSrCaCuO and TlCaBaCuO films. Because of resonant scattering from Ca at beam energies above 6 MeV, two backscattering measurements are required for these materials: one at 8.8 MeV to determine the O content, and one at or below 6 MeV to determine the Ca content. Anticipating a more general applicability of this technique to the analysis of metal-oxide films, data are also presented for a number of elements, as an empirical guideline, which give the beam energies above which scattering cross sections deviate from their Rutherford values, and must be determined experimentally. 10 refs., 6 figs., 4 tabs

Radiation protection of cyclotron vault with maze in PET Cyclotron Center

International Nuclear Information System (INIS)

Fueloep, Marko

2003-01-01

The PET Cyclotron center (PCC) is a complex for production, research and application of positron radiopharmaceuticals for PET (Positron Emission Tomography), which was commissioned this year (2004) in Bratislava, Slovak Republic. Positron radionuclides are produced by 18/9 MeV proton/deuteron cyclotron CYCLONE 18/9. Radiation protection of personnel and inhabitants against ionizing radiation in the PCC is solved with regard to the ICRP recommendations and Slovak regulatory system, protection rules and criteria and optimization of radiation protection. In the article comparisons of calculated and measured neutron and gamma dose equivalent rates around the CYCLONE 18/9 and at various points behind the shielding of cyclotron vault with maze are presented. Description of the CYCLONE 18/9 as a source of angular distribution of neutron energy spectra (production of 18 F was considered) was simulated by Monte Carlo code MCNPX. Code MCNP4B was used for shielding calculation of cyclotron vault with maze. Neutron energy spectra behind the shielding were measured by Bonner spectrometer. The values of neutron dose equivalent, which were calculated and measured around the CYCLONE 18/9 and at various points behind the shielding of cyclotron vault with maze, are within the range of factor 2. (authors)

Injection and extraction for cyclotrons

International Nuclear Information System (INIS)

Heikkinen, P.

1994-01-01

External ion sources for cyclotrons are needed for polarised and heavy ions. This calls for injection systems, either radial or axial. Radial injection is also needed when a cyclotron works as a booster after another cyclotron or a linear accelerator (usually tandem). Requirements for injection differ from separated sector cyclotrons where there is plenty of room to house inflectors and/or strippers, to superconducting cyclotrons where the space is limited by a small magnet gap, and high magnetic field puts other limitations to the inflectors. Several extraction schemes are used in cyclotrons. Stripping injection is used for H - and also for heavy ions where the q/m ratio is usually doubled. For other cases, electric and magnetic deflection has to be used. To increase the turn separation before the first deflector, both resonant and non-resonant schemes are used. In this lecture, external injection systems are surveyed and some rules to thumb for injection parameters are given. Extraction schemes are also reviewed. (orig.)

Medical cyclotron: why, where, how

International Nuclear Information System (INIS)

Scheer, Kurt; Comar, Dominique; Kellershohn, Claude

1976-01-01

Cyclotrons for medical purposes are particularly useful for the production of radioactive isotopes of elements normally constituting organic matter ( 15 O, 13 N, 11 C). The short half-life and positron emission of those elements are of great interest in medical diagnosis. Many others carrier-free radioisotopes can be produced by cyclotrons. Three categories of cyclotrons are mentioned. Desk top cyclotron only adapted to the production of short-lived radioisotopes in a hospital; low energy and average energy cyclotrons which require well-entrained personnel for their operation and are best adapted to the production of radioelements on a regional or even national scale. Examples relative to the interest of short-lived radioisotopes in lung and brain investigations and tumor detection are given

Cyclotrons for isotope production

International Nuclear Information System (INIS)

Milton, B.F.; Stevenson, N.R.

1995-06-01

Cyclotrons continue to be efficient accelerators for radioisotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology, and isotope production, as they relate to the new generation of commercial cyclotrons. We will also discuss the possibility of systems capable of extracted energies up to 100 MeV and extracted beam currents of up to 2.0 mA. (author). 6 refs., 2 tabs., 3 figs

Isochronous cyclotron data base description

International Nuclear Information System (INIS)

Kiyan, I.N.; Vorozhtsov, S.B.; Tarashkevich, R.

2004-01-01

The relational data base of the control parameters of the isochronous cyclotron, Isochronous Cyclotron Data Base (ICDB), is described. The relational data base under consideration, written in Transact SQL for the MS SQL Server 2000 with the use of MS Enterprise Manager and MS Query Analyzer, was installed on the server of the AIC144 isochronous cyclotron in Krakow, which operates under the control of the operating system MS Windows Server 2003 (Standard Edition). The interface of the data base under considerations is written in C++ with the use of Visual C++ .NET and is built in the Cyclotron Operator Help Program (COHP), which is used for modeling the operational modes of the isochronous cyclotron. Communication between the COHP and the relational data base is realised on the base of the Open Data Base Connectivity protocol. The relational data base of the control parameter of the isochronous cyclotron is intended: firstly, for systematization and automatic use of all measured and modelled magnetic field maps in the process of modeling the operational modes; secondly, for systematization and convenient access to the stored operational modes; thirdly, for simplifying the operator's work. The relational data base of the control parameter of the isochronous cyclotron reflects its physical structure and the logic of its operator's work. (author)

Fourier Transform Ion Cyclotron Resonance Mass Spectrometry at the Cyclotron Frequency.

Science.gov (United States)

Nagornov, Konstantin O; Kozhinov, Anton N; Tsybin, Yury O

2017-04-01

The phenomenon of ion cyclotron resonance allows for determining mass-to-charge ratio, m/z, of an ensemble of ions by means of measurements of their cyclotron frequency, ω c . In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the ω c quantity is usually unavailable for direct measurements: the resonant state is located close to the reduced cyclotron frequency (ω + ), whereas the ω c and the corresponding m/z values may be calculated via theoretical derivation from an experimental estimate of the ω + quantity. Here, we describe an experimental observation of a new resonant state, which is located close to the ω c frequency and is established because of azimuthally-dependent trapping electric fields of the recently developed ICR cells with narrow aperture detection electrodes. We show that in mass spectra, peaks close to ω + frequencies can be reduced to negligible levels relative to peaks close to ω c frequencies. Due to reduced errors with which the ω c quantity is obtained, the new resonance provides a means of cyclotron frequency measurements with precision greater than that achieved when ω + frequency peaks are employed. The described phenomenon may be considered for a development into an FT-ICR MS technology with increased mass accuracy for applications in basic research, life, and environmental sciences. Graphical Abstract ᅟ.

Building on TR-24 success. Advanced Cyclotron Systems Inc. launches a new cyclotron model

International Nuclear Information System (INIS)

Russell Watt; William Gyles; Alexander Zyuzin

2015-01-01

ACSI is designing a new 30 MeV cyclotron based on the TR-24. While minimizing changes from the proven TR-24, including maintaining the same outer dimensions, the energy of the cyclotron will be increased to 30 MeV, which will make it the most compact, non-superconducting, 30 MeV cyclotron design to date. Maximum beam current will match the TR-24 at 1 mA. With the size and footprint of a typical low energy PET cyclotron, this system will offer users a cost effective solution for a diversified facility capable of producing a wide spectrum of PET and SPECT radioisotopes for research and commercial distribution. (author)

Advances in superconducting cyclotrons at MSU

International Nuclear Information System (INIS)

Blosser, H.; Antaya, T.; Au, R.

1987-01-01

Intensive work on superconducting cyclotrons began at MSU in late 1973 (a brief earlier study had occurred in the early 1960's) and continues vigorously at present. One large cyclotron, the ''K500'', has been operating for a number of years, a second, the ''K800'', is nearing completion, the first operating tests of its magnet having occurred at the time of the previous conference, and a third, the ''medical cyclotron'', is now also nearing completion with first operation of its magnet expected just after the present conference. These cyclotrons like other superconducting cyclotrons are all dramatically smaller than comparable room temperature machines; overall weight is typically about 1/20th of that of room temperature cyclotrons of the same energy. This large reduction in the quantities of materials is partially offset by added complexity, but finally, a net overall cost savings of 50 to 70 % typically results; as a consequence the superconducting cyclotron is widely viewed as the cyclotron of the future. The thirteen years of experience at MSU involving three of these cyclotrons, together with much important work at other laboratories, gives a rather clear view of the advantages and disadvantages of various design approaches including by now a rather significant period of long term evaluation. This paper reviews highlights of this program. (author)

Medical cyclotron facilities

International Nuclear Information System (INIS)

1984-09-01

This report examines the separate proposals from the Austin Hospital and the Australian Atomic Energy Commission for a medical cyclotron facility. The proponents have argued that a cyclotron facility would benefit Australia in areas of patient care, availability and export of radioisotopes, and medical research. Positron emission tomography (PET) and neutron beam therapy are also examined

Development of Medical Cyclotron in KIRAMS

International Nuclear Information System (INIS)

Chai, Jong Seo; Jung, In Su; An, Dong Hyun

2005-01-01

This paper is presented on the development and status of medical cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS) at present. We have developed medical cyclotron which is KIRAMS-13. And the improvement of KIRAMS-13 is presented. Furthermore, the design of new cyclotrons, such as KIRAMS-5 and KIRAMS-30 cyclotron, are presented, and R and D studies for future plan of heavy ion accelerator are discussed

All-magnetic extraction for cyclotron beam reacceleration

Science.gov (United States)

Hudson, E.D.; Mallory, M.L.

1975-07-22

An isochronous cyclotron can be modified to provide an initial electron stripping stage, a complete acceleration of the stripped ions through the cyclotron to a first energy state, means for returning the ions to an intermediate cyclotron orbit through a second stripping stage, further acceleration of the now higher energy stripped ions through the cyclotron to their final energy, and final extraction of the ions from the cyclotron. (auth)

Sputtering yields of Si and Ni from the I sub(1-x)Si sub(x) system studied by Rutherford backscattering spectrometry

International Nuclear Information System (INIS)

Kim, Su-Chol; Yamaguchi, Satoru; Kataoka, Yoshihide; Iwami, Motohiro; Hiraki, Akio; Satou, Mamoru; Fujimoto, Fuminori.

1982-01-01

Sputtering yields of Si and Ni from thin layer films of Ni-Si compounds (Ni sub(1-x)Si sub(x)), including the pure materials (Ni and Si), caused by 5keV Ar + ion bombardment were investigated using backscattering spectrometry. The sputtering yield for Si from Ni sub(1-x)Si sub(x) increased with increasing Si concentration. However, there is an abrupt decrease in the yield for Si concentrations above NiSi 2 to pure Si. This is in clear contrast to the sputtering yield of Ni from Ni sub(1-x)Si sub(x) which increased with increasing Ni concentration monotonously. These results are discussed on the basis of both the difference in the atomic density and the electronic state of the alloy. (author)

Trends in cyclotrons for radionuclide production

International Nuclear Information System (INIS)

Vera Ruiz, H.; Lambrecht, R.M.

1999-01-01

The IAEA recently concluded a worldwide survey of the cyclotrons used for radionuclide production. Most of the institutions responded to the questionnaire. The responses identified technical, utilisation and administrative information for 206 cyclotrons. Compiled data includes the characteristics, performance and popularity of each of the different commercial cyclotrons. Over 20 cyclotrons are scheduled for installation in 1998. The expansion in the number of cyclotron installations during the last decade was driven by the advent of advances in medical imaging instrumentation (namely, positron emission tomography (PET), and more recently by 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons; and recent governmental decisions that permit reimbursement for cyclotron radiopharmaceutical studies by the government or insurance companies. The priorities for the production of clinical, commercial and research radionuclides were identified. The emphasis is on radionuclides used for medical diagnosis with SPET (e.g. 123 I, 201 Tl) and PET (e.g. 11 C, 13 N, 15 O, 18 F) radiopharmaceuticals, and for individualized patient radiation treatment planning (e.g. 64 Cu, 86 Y, 124 I) with PET. There is an emerging trend to advance the cyclotron as an alternative method to nuclear reactors for the production of neutron-rich radionuclides (e.g. 64 Cu, 103 Pd, 186 Re) needed for therapeutic applications. (authors)

Future cyclotron systems : an industrial perspective

International Nuclear Information System (INIS)

Stevenson, N.R.; Dickie, W.J.

1995-09-01

The use of commercial cyclotron systems for the production of radioisotopes continues to grow on a world-wide scale. Improvements in technology have significantly increased the production capabilities of modem cyclotron-based isotope production facilities. In particular, the change to negative ion acceleration and new high power systems have resulted in dramatic improvements in reliability, increases in capacity, and decreases in personnel radiation dose. As more and more older machines are retired decisions regarding their replacement are made based on several factors including the market's potential and the cyclotron system's abilities. Taking the case of the recently upgraded TR30 cyclotron at TRIUMF/Nordion, we investigate the requirements industrial/medical users are likely to impose on future commercial cyclotron systems and the impact this will have on cyclotron technology by the end of the century. (author)

Future cyclotron systems: An industrial perspective

International Nuclear Information System (INIS)

Stevenson, N.R.; Dickie, W.J.

1995-09-01

The use of commercial cyclotron systems for the production of radioisotopes continues to grow on a world-wide scale. Improvements in technology have significantly increased the production capabilities of modern cyclotron-based isotope production facilities. In particular, the change to negative ion acceleration and new high power systems have resulted in dramatic improvements in reliability, increases in capacity, and decreases in personnel radiation dose. As more and more older machines are retired, decisions regarding their replacement are made based on several factors including the market's potential and the cyclotron system's abilities. Taking the case of the recently upgraded TR30 cyclotron at TRIUMF/Nordion, the authors investigate the requirements industrial/medical users are likely to impose on future commercial cyclotron systems and the impact this will have on cyclotron technology by the end of the century

Experimenting from a Distance in the Case of Rutherford Scattering

Science.gov (United States)

Grober, S.; Vetter, M.; Eckert, B.; Jodl, H. -J.

2010-01-01

The Rutherford scattering experiment plays a central role in working out atomic models in physics and chemistry. Nevertheless, the experiment is rarely performed at school or in introductory physics courses at university. Therefore, we realized this experiment as a remotely controlled laboratory (RCL), i.e. the experiment is set up in reality and…

Ion-reversibility studies in amorphous solids using the two-atom scattering model

International Nuclear Information System (INIS)

Oen, O.S.

1981-06-01

An analytical two-atom scattering model has been developed to treat the recent discovery of the enhancement near 180 0 of Rutherford backscattering yields from disordered solids. In contrast to conventional calculations of Rutherford backscattering that treat scattering from a single atom only (the backscattering atom), the present model includes the interaction of a second atom lying between the target surface and the backscattering plane. The projectile ion makes a glancing collision with this second atom both before and after it is backscattered. The model predicts an enhancement effect whose physical origin arises from the tolerance of path for those ions whose inward and outward trajectories lie in the vicinity of the critical impact parameter. Results using Moliere scattering show how the yield enhancement depends on ion energy, backscattering depth, exit angle, scattering potential, atomic numbers of the projectile and target, and target density. In the model the critical impact parameter and critical angle play important roles. It is shown that these quantities depend on a single dimensionless parameter and analytical expressions for them are given which are accurate to better than 1%

Computer design of a compact cyclotron

International Nuclear Information System (INIS)

Bing Wang; Huanfeng Hao; Qinggao Yao; Jinquan Zhang; Mingtao Song; Vorozhtsov, S.B.; Smirnov, V.L.; Hongwei Zhao

2011-01-01

Here we present results of the computer design of the structural elements of a compact cyclotron by the example of HITFiL cyclotron selected as the driving accelerator that is under construction at the Institute of Modern Physics (Lanzhou, China). In the article a complex approach to modeling of the compact cyclotron, including calculation of electromagnetic fields of the structural elements and beam dynamics calculations, is described. The existing design data on the axial injection, magnetic, acceleration and extraction systems of the cyclotron are used as a starting point in the simulation. Some of the upgrades of the cyclotron structural elements were proposed, which led to substantial improvement of the beam quality and transmission

Low coupling loss core-strengthened Bi 2212\\/Ag Rutherford cables

CERN Document Server

Collings, E W; Scanlan, R M; Dietderich, D R; Motowidlo, L R

1999-01-01

In a comprehensive "vertically integrated" program multifilamentary (MF) high temperature superconducting (HTSC) Bi:2212/Ag strand was fabricated using the powder-in-tube process and heat treated in oxygen by a modified standard $9 procedure. The reaction-heat-treatment (HT) was adjusted to maximize critical current (density), I/sub c/ (J /sub c/), as measured in various magnetic fields, B. A series of Rutherford cables was designed, each of which included a $9 metallic (Nichrome-80) core for strengthening and reduction of coupling loss. Prior to cable winding a series of tests examined the possibility of strand "poisoning" by the core during HT. Small model Rutherford cables were wound, $9 and after HT were prepared for I/sub c/(B) measurement and calorimetric measurement of AC loss and hence interstrand contact resistance I/sub c/(B). It was deduced that, if in direct contact with the strand during HT, the core $9 material can degrade the I/sub c/ of the cable; but steps can be taken to eliminate this probl...

Startup work on Inshas cyclotron

International Nuclear Information System (INIS)

Vorogushin, M.F.; Strokach, A.P.; Shikhov, V.Ya.; Galchuk, A.V.; Soliman, A.N.; El-Abyad, M.; Comsan, M.N.H.; Saleh, Z.A.; Azzam, A.N.

2001-01-01

Startup works on the MGC-20 variable energy cyclotron in the Inshas Nuclear Research Center (Egypt) are described. The cyclotron is intended for acceleration of hydrogen and helium ions in a wide energy range (for protons - from 5 to 20 MeV). Main units of the cyclotron and results of computer experimental acceleration of protons to 18 MeV are described. The prospects of furthers investigations are presented [ru

Sputtering yields of Si and Ni from the Ni sub(1-x)Si sub(x) system studied by Rutherford backscattering spectrometry

Energy Technology Data Exchange (ETDEWEB)

Kim, S C; Yamaguchi, S; Kataoka, Y; Iwami, M; Hiraki, A [Osaka Univ., Suita (Japan). Faculty of Engineering; Satou, M; Fujimoto, F

1982-01-01

Sputtering yields of Si and Ni from thin layer films of Ni-Si compounds (Ni sub(1-x)Si sub(x)), including the pure materials (Ni and Si), caused by 5keV Ar/sup +/ ion bombardment were investigated using backscattering spectrometry. The sputtering yield for Si from Ni sub(1-x)Si sub(x) increased with increasing Si concentration. However, there is an abrupt decrease in the yield for Si concentrations above NiSi/sub 2/ to pure Si. This is in clear contrast to the sputtering yield of Ni from Ni sub(1-x)Si sub(x) which increased with increasing Ni concentration monotonously. These results are discussed on the basis of both the difference in the atomic density and the electronic state of the alloy.

Difference in Stability Between Edge and Center in a Rutherford Cable

NARCIS (Netherlands)

Willering, G.P.; Verweij, A.P.; Scheuerlein, C.; den Ouden, A.; ten Kate, Herman H.J.

Keystoned superconducting Rutherford cables are widely used in accelerator magnets like in the LHC at CERN. An essential requirement in the cable design is its stability against local heat releases in the magnet windings originating from for example, strand movement or beam loss. Beam loss is the

PREFACE: Rutherford Centennial Conference on Nuclear Physics

Science.gov (United States)

Freeman, Sean

2012-09-01

Just over one hundred years ago, Ernest Rutherford presented an interpretation of alpha-particle scattering experiments, performed a couple of years earlier by Geiger and Marsden, to the Manchester Literary and Philosophical Society. The work was summarised shortly afterwards in a paper in the Philosophical Magazine. He postulated that a dense speck of matter must exist at the centre of an atom (later to become known as the nucleus) if the details of the experiments, particularly the yield of alpha particles scattered through large angles, were to be explained. The nuclear hypothesis, combined with the experimental work by Moseley on X-rays and Bohr's theoretical ideas, both also initiated at the Victoria University of Manchester, established our view of atomic structure and gave birth to the field of nuclear physics. The Rutherford Centennial Conference on Nuclear Physics was held at The University of Manchester in August 2011 to celebrate this anniversary by addressing the wide range of contemporary topics that characterise modern nuclear physics. This set of proceedings covers areas including nuclear structure and astrophysics, hadron structure and spectroscopy, fundamental interactions studied within the nucleus and results of relativistic heavy-ion collisions. We would like to thank all those who presented their recent research results at the conference; the proceedings stand as a testament to the excitement and interest that still pervades the pursuit of this field of physics. We would also like to thank those who contributed in other ways to the conference. To colleagues at the Manchester Museum of Science and Industry for putting together an exhibition to coincide with the conference that included the manuscript of the 1911 paper, letters, notebooks and equipment used by Rutherford. These items were kindly loaned by Cambridge and Manchester Universities. Winton Capital generously supported this exhibition. We would also like to thank Professor Mary Fowler

Bulk media assay using backscattered neutron spectrometry

International Nuclear Information System (INIS)

Csikai, J.

2000-01-01

This paper summarized a systematic study of bulk media assay using backscattered neutron spectrometry. The source-sample-detector geometry used for the measurements of leakage and elastically backscattered (EBS) spectra of neutrons is shown. Neutrons up to about 14 MeV were produced via 2 H (d,n) and 9 Be (d,n) reactions using different deuteron beam energies between 5 and 10 MeV at the MGC-20E cyclotron of ATOMKI (Debrecen). Neutron yields of the Pu-Be and 252 Cf sources were 5.25 x 10 6 n/s and 1.8 x 10 6 n/s, respectively. Flux density distributions of thermal and primary 14 MeV neutrons were measured for graphite, water and coal samples in various moderator (M)-sample (S)-reflector (R) geometries. Relative fractions and integrated yields of 252 Cf, Pu-Be and 14 MeV neutrons above the (n,n'γ) reaction thresholds for 12 C, 16 O and 28 Si isotopes vs sample thickness have also been determined. It was found that the integrated reaction rate vs sample thickness decreasing exponentially with different attenuation coefficients depending on the neutron spectrum and the composition of the sample. The spectra of neutrons from sources passing through slabs of water, graphite, sand, Al, Fe and Pb up to 20 cm in thickness have been measured by a PHRS system in the 1.2 to 1.5 MeV range. The leakage neutron spectra from a Pu-Be source placed in the center of 30 cm diameter sphere filled with water, paraffin oil, SiO 2 , zeolite and river sand were also measured. The measured spectra have been compared with the calculated results obtained by the three dimensional Monte-Carlo code MCNP-4A and point-wise cross sections from the ENDF/B-4, ENDF/B-6, ENDF/E-1, BROND-2 and JENDL-3.1 data files. New results were obtained for validation of different data libraries from a comparison on the measured and the calculated spectra. Some typical results for water, Al, sand and Fe are shown. A combination of the backscattered neutron spectrometry with the surface gauge used both for the

Lord Rutherford of Nelson, his 1908 Nobel Prize in Chemistry, and why he didn't get a second prize

International Nuclear Information System (INIS)

Jarlskog, Cecilia

2008-01-01

'I have dealt with many different transformations with various periods of time, but the quickest that I have met was my own transformation in one moment from a physicist to a chemist.' Ernest Rutherford (Nobel Banquet, 1908) This article is about how Ernest Rutherford (1871-1937) got the 1908 Nobel Prize in Chemistry and why he did not get a second Prize for his subsequent outstanding discoveries in physics, specially the discovery of the atomic nucleus and the proton. Who were those who nominated him and who did he nominate for the Nobel Prizes? In order to put the Prize issue into its proper context, I will briefly describe Rutherford's whereabouts. Rutherford, an exceptionally gifted scientist who revolutionized chemistry and physics, was moulded in the finest classical tradition. What were his opinions on some scientific issues such as Einstein's photon, uncertainty relations and the future prospects for atomic energy? What would he have said about the 'Theory of Everything'? Extended version of an invited talk presented at the conference 'Neutrino 2008', Christchurch, NZ, 25-31 May 2008

A line-of-sight electron cyclotron emission receiver for electron cyclotron resonance heating feedback control of tearing modes

DEFF Research Database (Denmark)

Oosterbeek, J.W.; Bürger, A.; Westerhof, E.

2008-01-01

An electron cyclotron emission (ECE) receiver inside the electron cyclotron resonance heating (ECRH) transmission line has been brought into operation. The ECE is extracted by placing a quartz plate acting as a Fabry-Perot interferometer under an angle inside the electron cyclotron wave (ECW) bea...

Backscatter measurements for NIF ignition targets (invited).

Science.gov (United States)

Moody, J D; Datte, P; Krauter, K; Bond, E; Michel, P A; Glenzer, S H; Divol, L; Niemann, C; Suter, L; Meezan, N; MacGowan, B J; Hibbard, R; London, R; Kilkenny, J; Wallace, R; Kline, J L; Knittel, K; Frieders, G; Golick, B; Ross, G; Widmann, K; Jackson, J; Vernon, S; Clancy, T

2010-10-01

Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of ∼15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.

Backscatter measurements for NIF ignition targets (invited)

Energy Technology Data Exchange (ETDEWEB)

Moody, J. D.; Datte, P.; Krauter, K.; Bond, E.; Michel, P. A.; Glenzer, S. H.; Divol, L.; Suter, L.; Meezan, N.; MacGowan, B. J.; Hibbard, R.; London, R.; Kilkenny, J.; Wallace, R.; Knittel, K.; Frieders, G.; Golick, B.; Ross, G.; Widmann, K.; Jackson, J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); and others

2010-10-15

Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of {approx}15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.

Backscatter measurements for NIF ignition targets (invited)

International Nuclear Information System (INIS)

Moody, J. D.; Datte, P.; Krauter, K.; Bond, E.; Michel, P. A.; Glenzer, S. H.; Divol, L.; Suter, L.; Meezan, N.; MacGowan, B. J.; Hibbard, R.; London, R.; Kilkenny, J.; Wallace, R.; Knittel, K.; Frieders, G.; Golick, B.; Ross, G.; Widmann, K.; Jackson, J.

2010-01-01

Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of ∼15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.

The collected papers of Lord Rutherford of Nelson

CERN Document Server

Rutherford, Ernest

1962-01-01

This is the third of three volumes which together contain the complete range of Lord Rutherford's scientific papers, incorporating in addition addresses, general lectures, letters to editors, accounts of his scientific work and personal recollections by friends and colleagues. The final volume, first published in 1965, covers his period as Cavendish Professor from 1919 to 1937. Following on the immense fertility of his years in Manchester - only overshadowed towards the end by the war - we now turn to his last years as a world figure at the Cavendish Laboratory, where he continued his work on

Study on interstrand coupling losses in Rutherford-type superconducting cables

International Nuclear Information System (INIS)

Lei, Y.Z.; Shintomi, T.; Terashima, A.; Hirabayashi, H.

1993-02-01

Two sets of experimental apparatus for measuring the AC losses in superconducting strands and Rutherford-type cable conductors have been constructed. A few strand samples and a number of compacted cable samples with and without a CuMn matrix have been measured. The hysteresis loss, loss from coupling within strands and loss from coupling between strands in cables have been distinguished from each other. The results show that, even for Rutherford cables without any soldering and coating, their AC losses may be quite different from each other due to the variation of the interstrand coupling loss. For cables without a CuMn matrix, interstrand coupling loss increases nearly according to a geometrical series with an increase of curing temperature simulating coil fabrication. However, cables with the CuMn matrix show a relatively small curing temperature dependence. For most of the samples, losses do not show any evident dependence on the mechanical pressure. Interstrand resistances in one of these cables have also been measured; the results indicate that the tendency for a decrease in the interstrand resistances is consistent with the results of AC loss measurements. (author)

Method and apparatus for ion cyclotron spectrometry

Science.gov (United States)

Dahl, David A [Idaho Falls, ID; Scott, Jill R [Idaho Falls, ID; McJunkin, Timothy R [Idaho Falls, ID

2010-08-17

An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber that includes at least a first section that induces a first magnetron effect that increases a cyclotron frequency of an ion and at least a second section that induces a second magnetron effect that decreases the cyclotron frequency of an ion. The cyclotron frequency changes induced by the first and second magnetron effects substantially cancel one another so that an ion traversing the at least first and second sections will experience no net change in cyclotron frequency.

Commercial compact cyclotrons in the 90's

International Nuclear Information System (INIS)

Milton, B.F.

1995-09-01

Cyclotrons continue to be efficient accelerators for radio-isotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicate a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology, as they relate to the new generation of commercial cyclotrons. Design criteria for the different types of commercial cyclotrons will be presented, with reference to those demands that differ from those in a research oriented cyclotron project. We will also discuss the possibility of systems designed for higher energies and capable of extracted beam currents of up to 2.0 mA. (author)

Commercial compact cyclotrons in the 90's

International Nuclear Information System (INIS)

Milton, B.F.

1995-09-01

Cyclotrons continue to be efficient accelerators for radio-isotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicate a strong future for commercial cyclotrons. In this paper the authors will survey recent developments in the areas of cyclotron technology, as they relate to the new generation of commercial cyclotrons. Design criteria for the different types of commercial cyclotrons will be presented, with reference to those demands that differ from those in a research oriented cyclotron project. The authors also discuss the possibility of systems designed for higher energies and capable of extracted beam currents of up to 2.0 mA

Multibeam sonar backscatter data processing

Science.gov (United States)

Schimel, Alexandre C. G.; Beaudoin, Jonathan; Parnum, Iain M.; Le Bas, Tim; Schmidt, Val; Keith, Gordon; Ierodiaconou, Daniel

2018-06-01

Multibeam sonar systems now routinely record seafloor backscatter data, which are processed into backscatter mosaics and angular responses, both of which can assist in identifying seafloor types and morphology. Those data products are obtained from the multibeam sonar raw data files through a sequence of data processing stages that follows a basic plan, but the implementation of which varies greatly between sonar systems and software. In this article, we provide a comprehensive review of this backscatter data processing chain, with a focus on the variability in the possible implementation of each processing stage. Our objective for undertaking this task is twofold: (1) to provide an overview of backscatter data processing for the consideration of the general user and (2) to provide suggestions to multibeam sonar manufacturers, software providers and the operators of these systems and software for eventually reducing the lack of control, uncertainty and variability associated with current data processing implementations and the resulting backscatter data products. One such suggestion is the adoption of a nomenclature for increasingly refined levels of processing, akin to the nomenclature adopted for satellite remote-sensing data deliverables.

Ion-cyclotron-resonance- and Fourier-transform-ion-cyclotron-resonance spectroscopy: technology and application

International Nuclear Information System (INIS)

Luederwald, I.

1977-01-01

Instrumentation and technology of Ion-Cyclotron-Resonance and Fourier-Transform-Ion-Cyclotron-Resonance Spectroscopy are described. The method can be applied to studies of ion/molecule reactions in gas phase, to obtain thermodynamic data as gas phase acidity or basicity, proton and electron affinity, and to establish reaction mechanisms and ion structures. (orig.) [de

Developing the smallest possible medical cyclotron

CERN Multimedia

Katarina Anthony

2011-01-01

Imagine a portable medical cyclotron operated in a conventional radioactive facility at a hospital. Imagine a nurse or technician switching it on and producing isotopes at the patient’s bedside. Sounds like science fiction? Think again.   CERN has teamed up with Spain’s national scientific research centre (CIEMAT) to develop an avant-garde cyclotron to be used for Positron Emission Tomography (PET). “We plan to make a cyclotron that doesn't need an insulated building or ‘vault’: a cyclotron small enough to fit inside a hospital lift,” explains Jose Manuel Perez, who is leading the CIEMAT/CERN collaboration. “It will be the smallest possible medical cyclotron for single patient dose production and will dramatically reduce costs for hospitals.” While PET technology has transformed imaging techniques, many of its medical benefits have remained confined to highly specialised hospitals. “Studies have foun...

RUTHERFORD/APPELTON: ISIS intensity record

International Nuclear Information System (INIS)

Anon.

1993-01-01

The Rutherford Appleton Laboratory in the UK is home to the world's most intense pulsed neutron source. The heart of ISIS is a 50 Hz proton synchrotron accelerating two bunches of protons from 70 to 800 MeV. After extraction the protons, occupying a total pulse length of less than 0.5 microseconds, strike a heavy metal target: the neutrons generated are moderated and directed through channels in the shielding to any of 14 instruments for condensed matter studies. As neutrinos and muons are copious byproducts, major investments have also been made for investigations in these fields. Efficient charge exchange injection into the synchrotron at 70 MeV is achieved using negative hydrogen ions and an aluminium oxide stripping foil. Some particles are lost during trapping and the early acceleration period, but they are captured by graphite-covered beam collectors to reduce machine activation. Later acceleration and fast-extraction are virtually without loss

Medical cyclotron basic concepts and its applications

International Nuclear Information System (INIS)

Kumar, Rajeev; Sonkawade, R.G.

2012-01-01

More than 3000 nuclides are known, of which approximately 2700 are radioactive, and rest are stable. The majority of radionuclides are artificially produced in the reactor and cyclotron. In a cyclotron, Charge particle such as proton, Deuteron, á (Alpha) particle, 3 He particles and so forth are accelerated in circular paths within the Dees under vacuum by means of an electromagnetic field. These accelerated particles can possess few KeV to several BeV of kinetic energy depending on the design of the cyclotron. At our setup we have an 11 MeV dual beam multi target cyclotron which is capable producing 11 C, 13 N, 15 O, 18 F and 2 F radioisotopes and all have been successfully produced and tested in our lab. Earlier cyclotrons were the best source of high-energy beams for nuclear physics experiments; several cyclotrons are still in use for this type of research. Cyclotrons can be used to treat cancer. Ion beams from cyclotrons can be used, as in proton therapy. The positron emitting isotopes are suitable for PET imaging. As discussed we are producing mainly Carbon-11, Nitrogen-13, Oxygen-15, and Fluorine-18: These are positron emitters used in PET for studying brain physiology and pathology, in particular for localizing epileptic focus, and in dementia, psychiatry and neuropharmacology studies. So these are having significant role in diagnosis of Oncological, Neurological and Cardiological disorder. More than ninety percent we are producing 18 F in FDG. 18 F in FDG (Flouro-Deoxy-glucose) has become very important in detection of cancers and the monitoring of progress in their treatment, using PET. Medical cyclotron is complex equipment requiring delicate handling by highly trained personnel. The aim of this article is to highlight few finer aspects of Medical cyclotron operation, including precautions for safety and smooth functioning of this sophisticated equipment. (author)

20 years Rossendorf cyclotron

International Nuclear Information System (INIS)

1978-08-01

On the occasion of the 20th anniversary of initiating of the Rossendorf cyclotron accounts are given of most important works and results in the field of accelerator engineering and utilization of this machine. The reports show the trend of development and actual spectrum of application. The enclosed literature lists give a survey of technical and experimental works at cyclotron. (author)

Medical cyclotrons

International Nuclear Information System (INIS)

Wolf, A.P.

1976-01-01

Cyclotrons as tools for therapy and for the production of radionuclides for use in nuclear medicine have been extensively reviewed in the literature. The current world status with respect to cyclotrons used primarily for research, development and application in nuclear medicine is reviewed here in the context of geographical distribution and type of use, presently available commercial types, machine characteristics and trends. Aspects of design requirements from a user perspective such as machine, beam and target characteristics are covered. Some special problems concerning many factors which can lead to effective production of the desired radionuclide or product are considered in light of machine characteristics. Consideration is also given to future directions for accelerators in nuclear medicine

Study of Transient Heat Transport Mechanisms in Superfluid Helium Cooled Rutherford-Cables

CERN Document Server

AUTHOR|(CDS)2100615

The Large Hadron Collider leverages superconducting magnets to focus the particle beam or keep it in its circular track. These superconducting magnets are composed of NbTi-cables with a special insulation that allows superfluid helium to enter and cool the superconducting cable. Loss mechanisms, e.g. continuous random loss of particles escaping the collimation system heating up the magnets. Hence, a local temperature increase can occur and lead to a quench of the magnets when the superconductor warms up above the critical temperature. A detailed knowledge about the temperature increases in the superconducting cable (Rutherford type) ensures a secure operation of the LHC. A sample of the Rutherford cable has been instrumented with temperature sensors. Experiments with this sample have been performed within this study to investigate the cooling performance of the helium in the cable due to heat deposition. The experiment uses a superconducting coil, placed in a cryostat, to couple with the magnetic field loss m...

Application of superconductivity in cyclotron construction

International Nuclear Information System (INIS)

Blosser, H.G.

1982-01-01

This paper reviews major concepts and design features of the new class of cyclotrons which use superconducting coils to provide main magnet excitation. The discussion begins with a brief historical review tracing the evolution of these ''superconducting'' cyclotrons and the impact of this application of superconductivity in pushing back traditional cyclotron construction limits. This is followed by a review of the principal phenomena which come into play to set new limits on the operating regime, and the nature of these limits, some of which arise from orbit properties and some of which result from construction intricacies in the coil and in the rf system. Conclusions anticipate a future widely encompassing role in the application of superconductivity to cyclotron

National Medical Cyclotron

International Nuclear Information System (INIS)

Boyd, Rex.

1991-01-01

The National Medical Cyclotron, under construction at Sydney's Royal Prince Alfred Hospital(RPAH) is to be operated by the Australian Nuclear Science and Technology Organization in collaboration with the hospital. Its main purpose is to produce radioisotopes on commercial basis for distribution to hospitals through Australia as well as short-lived radioisotopes (2 minutes to 2 hours) for immediate application at RPAH in Positron Emission Tomography, to study the dynamics of human physiology and metabolism in organs, bones and soft tissues. A list of the principal cyclotron-produced radionuclides is provided. ills

How cyclotrons work

International Nuclear Information System (INIS)

Nolan, D.

1992-01-01

The operating principles of a cyclic accelerator are presented based on the IBA Cyclone 30 negative ion cyclotron, selected for the Australia's first medical cyclotron. Its main features are: acceleration with variable energy of between 15-30 million electron volts, the capability of extracting two beams simultaneously, low power consumption, easy maintenance. Other aspects not directly related to the principle of operation discussed include the vacuum and the radio-frequency systems as well as the complex computerized control system used to automatically control start-up and shut-down operations. ills

Spatially coded backscatter radiography

International Nuclear Information System (INIS)

Thangavelu, S.; Hussein, E.M.A.

2007-01-01

Conventional radiography requires access to two opposite sides of an object, which makes it unsuitable for the inspection of extended and/or thick structures (airframes, bridges, floors etc.). Backscatter imaging can overcome this problem, but the indications obtained are difficult to interpret. This paper applies the coded aperture technique to gamma-ray backscatter-radiography in order to enhance the detectability of flaws. This spatial coding method involves the positioning of a mask with closed and open holes to selectively permit or block the passage of radiation. The obtained coded-aperture indications are then mathematically decoded to detect the presence of anomalies. Indications obtained from Monte Carlo calculations were utilized in this work to simulate radiation scattering measurements. These simulated measurements were used to investigate the applicability of this technique to the detection of flaws by backscatter radiography

Investigation of ionic movements during anodic oxidation of superimposed metallic layers by the use of Rutherford backscattering techniques and nuclear micro analysis

International Nuclear Information System (INIS)

Perriere, J.; Siejka, J.; Rigo, S.

1980-01-01

Nuclear micro-analysis by the direct observation of nuclear reactions and of backscattered particles was used to study ionic movements during the anodization of superimposed metallic films (M 1 -M 2 systems). It has been shown that the order of cations is largely preserved during the anodization of Ta-Nb or Al-Nb systems while it is inverted in the case of Nb-Ta and Nb-Al systems. These results are discussed in terms of differences in jump probabilities of atoms. The oxygen movements in these systems were studied by 18 O tracing techniques; the results suggest that a correlation exists between oxygen and cationic migration during anodic oxide growth. The discussion of these results in terms of microscopic transport mechanisms is based on a neighbour to neighbour type propagation process for cationic as well as oxygen movement. (author)

Cyclotrons and positron emitting radiopharmaceuticals

International Nuclear Information System (INIS)

Wolf, A.P.; Fowler, J.S.

1984-01-01

The state of the art of Positron Emission Tomography (PET) technology as related to cyclotron use and radiopharmaceutical production is reviewed. The paper discusses available small cyclotrons, the positron emitters which can be produced and the yields possible, target design, and radiopharmaceutical development and application. 97 refs., 12 tabs

A new cyclotron for biomedical research

International Nuclear Information System (INIS)

Wolber, G.

1988-01-01

This paper presents the rationale for replacing the old AEG Compact Cyclotron (built in 1969/71) of the Institute for Radiology and Pathophysiology at the German Cancer Research Center by a 30 MeV H - /15 MeV D - cyclotron. A status report is followed by the scientific and technical reasoning as well as budgetary and organizational considerations. In the appendix we tried to explain the function of a cyclotron in a simple and comprehensive manner. (orig.) [de

Properties of hydrogenated amorphous silicon (a-Si:H) deposited using a microwave Ecr plasma

International Nuclear Information System (INIS)

Mejia H, J.A.

1996-01-01

Hydrogenated amorphous silicon (a-Si:H) films have been widely applied to semiconductor devices, such as thin film transistors, solar cells and photosensitive devices. In this work, the first Si-H-Cl alloys (obtained at the National Institute for Nuclear Research of Mexico) were formed by a microwave electron cyclotron resonance (Ecr) plasma CVD method. Gaseous mixtures of silicon tetrachloride (Si Cl 4 ), hydrogen and argon were used. The Ecr plasma was generated by microwaves at 2.45 GHz and a magnetic field of 670 G was applied to maintain the discharge after resonance condition (occurring at 875 G). Si and Cl contents were analyzed by Rutherford Backscattering Spectrometry (RBS). It was found that, increasing proportion of Si Cl 4 in the mixture or decreasing pressure, the silicon and chlorine percentages decrease. Optical gaps were obtained by spectrophotometry. Decreasing temperature, optical gap values increase from 1.4 to 1.5 eV. (Author)

Properties of hydrogenated amorphous silicon (a-Si:H) deposited using a microwave Ecr plasma; Propiedades del a-Si:H depositado utilizando un plasma de microondas

Energy Technology Data Exchange (ETDEWEB)

Mejia H, J A

1997-12-31

Hydrogenated amorphous silicon (a-Si:H) films have been widely applied to semiconductor devices, such as thin film transistors, solar cells and photosensitive devices. In this work, the first Si-H-Cl alloys (obtained at the National Institute for Nuclear Research of Mexico) were formed by a microwave electron cyclotron resonance (Ecr) plasma CVD method. Gaseous mixtures of silicon tetrachloride (Si Cl{sub 4}), hydrogen and argon were used. The Ecr plasma was generated by microwaves at 2.45 GHz and a magnetic field of 670 G was applied to maintain the discharge after resonance condition (occurring at 875 G). Si and Cl contents were analyzed by Rutherford Backscattering Spectrometry (RBS). It was found that, increasing proportion of Si Cl{sub 4} in the mixture or decreasing pressure, the silicon and chlorine percentages decrease. Optical gaps were obtained by spectrophotometry. Decreasing temperature, optical gap values increase from 1.4 to 1.5 eV. (Author).

Cyclotron Phase-Coherent Ion Spatial Dispersion in a Non-Quadratic Trapping Potential is Responsible for FT-ICR MS at the Cyclotron Frequency

Science.gov (United States)

Nagornov, Konstantin O.; Kozhinov, Anton N.; Tsybin, Yury O.

2018-01-01

Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) at the cyclotron frequency instead of the reduced cyclotron frequency has been experimentally demonstrated using narrow aperture detection electrode (NADEL) ICR cells. Here, based on the results of SIMION simulations, we provide the initial mechanistic insights into the cyclotron frequency regime generation in FT-ICR MS. The reason for cyclotron frequency regime is found to be a new type of a collective motion of ions with a certain dispersion in the initial characteristics, such as pre-excitation ion velocities, in a highly non-quadratic trapping potential as realized in NADEL ICR cells. During ion detection, ions of the same m/z move in phase for cyclotron ion motion but out of phase for magnetron (drift) ion motion destroying signals at the fundamental and high order harmonics that comprise reduced cyclotron frequency components. After an initial magnetron motion period, ion clouds distribute into a novel type of structures - ion slabs, elliptical cylinders, or star-like structures. These structures rotate at the Larmor (half-cyclotron) frequency on a plane orthogonal to the magnetic field, inducing signals at the true cyclotron frequency on each of the narrow aperture detection electrodes. To eliminate the reduced cyclotron frequency peak upon dipolar ion detection, a number of slabs or elliptical cylinders organizing a star-like configuration are formed. In a NADEL ICR cell with quadrupolar ion detection, a single slab or an elliptical cylinder is sufficient to minimize the intensity of the reduced cyclotron frequency components, particularly the second harmonic. [Figure not available: see fulltext.

Cyclotrons and positron emitting radiopharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

Wolf, A.P.; Fowler, J.S.

1984-01-01

The state of the art of Positron Emission Tomography (PET) technology as related to cyclotron use and radiopharmaceutical production is reviewed. The paper discusses available small cyclotrons, the positron emitters which can be produced and the yields possible, target design, and radiopharmaceutical development and application. 97 refs., 12 tabs. (ACR)

submitter Optimization of Nb$_{3}$Sn Rutherford Cables Geometry for the High Luminosity LHC

CERN Document Server

Fleiter, Jerome; Bonasia, Angelo; Bordini, Bernardo; Richter, David

2017-01-01

The quadrupole and dipole magnets for the LHC High Luminosity (HL-LHC) upgrade will be based on Nb$_{3}$Sn Rutherford cables that operate at 1.9 K and experience magnetic fields of up to about 12 T. An important step in the design of these magnets is the development of the high aspect ratio Nb$_{3}$Sn cables to achieve the nominal field with sufficient margin. The strong plastic deformation of unreacted $Nb_3Sn$ strands during the Rutherford cabling process may induce non negligible $I_c$ and RRR degradation. In this paper, the cabling degradation is investigated as a function of the cable geometry for both PIT and RRP conductors. Based on this analysis, new baseline geometries for both 11 T and QXF magnets of HL-LHC are proposed.

submitter Optimization of Nb$_{3}$Sn Rutherford Cables Geometry for the High Luminosity LHC

CERN Document Server

Fleiter, Jerome; Bonasia, Angelo; Bordini, Bernardo; Richter, David

2017-01-01

The quadrupole and dipole magnets for the LHC High Luminosity (HL-LHC) upgrade will be based on Nb3Sn Rutherford cables that operate at 1.9 K and experience magnetic fields of up to about 12 T. An important step in the design of these magnets is the development of the high aspect ratio Nb3Sn cables to achieve the nominal field with sufficient margin. The strong plastic deformation of unreacted $Nb_3Sn$ strands during the Rutherford cabling process may induce non negligible $I_c$ and RRR degradation. In this paper, the cabling degradation is investigated as a function of the cable geometry for both PIT and RRP conductors. Based on this analysis, new baseline geometries for both 11 T and QXF magnets of HL-LHC are proposed.

Cyclotron method for heavy ion acceleration

International Nuclear Information System (INIS)

Gikal, B.N.; Gul'bekyan, G.G.; Kutner, V.B.; Oganesyan, R.Ts.

1984-01-01

Studies on heavy ion beams in a wide range of masses (up to uranium) and energies disclose essential potential opportunities for solution of both fundamental scientific and significant economical problems. A cyclotron method for heavy ion acceleration is considered. Development of low and medium energy heavy ion accelerators is revealed. The design of a complex comprising two isochronous cyclotrons which is planned to be constrdcted 1n the JINR is described. The cyclotron complex includes the U-400 and the U-400 M cyclotrons and it is intended for acceleration of both 35-20 MeV/nucleon superheavy ions such as Xe-U and 120 MeV/nucleon light ions. Certain systems of the accelerators are described. Prospects of the U-400 and the U-400 M development are displayed

Lord Rutherford of Nelson, his 1908 Nobel Prize in Chemistry, and why he didn't get a second prize

Energy Technology Data Exchange (ETDEWEB)

Jarlskog, Cecilia [Division of Mathematical Physics, LTH, Lund University, Box 118, S-22100 Lund (Sweden)], E-mail: cecilia.jarlskog@matfys.lth.se

2008-11-01

'I have dealt with many different transformations with various periods of time, but the quickest that I have met was my own transformation in one moment from a physicist to a chemist.' Ernest Rutherford (Nobel Banquet, 1908) This article is about how Ernest Rutherford (1871-1937) got the 1908 Nobel Prize in Chemistry and why he did not get a second Prize for his subsequent outstanding discoveries in physics, specially the discovery of the atomic nucleus and the proton. Who were those who nominated him and who did he nominate for the Nobel Prizes? In order to put the Prize issue into its proper context, I will briefly describe Rutherford's whereabouts. Rutherford, an exceptionally gifted scientist who revolutionized chemistry and physics, was moulded in the finest classical tradition. What were his opinions on some scientific issues such as Einstein's photon, uncertainty relations and the future prospects for atomic energy? What would he have said about the 'Theory of Everything'? Extended version of an invited talk presented at the conference 'Neutrino 2008', Christchurch, NZ, 25-31 May 2008.

Lessons from two paradigmatic developments; Rutherford's nuclear atom and halo nuclei

International Nuclear Information System (INIS)

Vaagen, J S; Ershov, S N; Zhukov, M V

2012-01-01

In its initial 1911 version, underpinned by discoveries in alpha-scattering experiments, Rutherford's atom model made a gross separation of neutral matter; A veil of light negative matter surrounding a tiny impenetrable heavy positive core. The model had however little to say about the atomic (electronic) architecture and dynamics, hence did not make it straight to the catwalk of physics of those days. Three quarters of a century later, in 1985, new discoveries in collision experiments revealed existence of abnormally large light nuclei, but could say less about the nuclear architecture. History sometimes repeats itself: Like Bohr's ad hoc planetary model (1913) changed the fate of Rutherford's discovery, again Scandinavian inspired ideas on architecture, this time nuclear halos, changed our paradigm for the heart of matter. We comment on the need for a concerted Rutherfordian effort between theory and increasingly complete reaction experiments if further ground-breaking progress is going to be made in halo physics, and physics in vicinities of neutron and proton driplines, and generally in the more widely growing field of many-body open quantum systems, where structure and reactions come together.

Commercial cyclotrons. Part I: Commercial cyclotrons in the energy range 10 30 MeV for isotope production

Science.gov (United States)

Papash, A. I.; Alenitsky, Yu. G.

2008-07-01

A survey of commercial cyclotrons for production of medical and industrial isotopes is presented. Compact isochronous cyclotrons which accelerate negative hydrogen ions in the energy range 10 30 MeV have been widely used over the last 25 years for production of medical isotopes and other applications. Different cyclotron models for the energy range 10 12 MeV with moderate beam intensity are used for production of 11C, 13N, 15O, and 18F isotopes widely applied in positron emission tomography. Commercial cyclotrons with high beam intensity are available on the market for production of most medical and industrial isotopes. In this work, the physical and technical parameters of different models are compared. Possibilities of improving performance and increasing intensity of H- beams up to 2 3 mA are discussed.

Solid targetry for compact cyclotrons

International Nuclear Information System (INIS)

Comor, J.

2004-01-01

In this presentation authors present experimental results of solid targetry for compact cyclotrons. It is concluded: Solid targetry is not restricted to large accelerator centers anymore; Small and medium scale radioisotope production is feasible with compact cyclotrons; The availability of versatile solid target systems is expected to boost the radiochemistry of 'exotic' positron emitters

Fast optics for the Rutherford laser compression experiments

International Nuclear Information System (INIS)

Micholas, D.J.

1976-12-01

The compression chamber optical system proposed for the Rutherford Laboratory Laser compression experiments is described. The system corrects for longitudinal spherical aberration giving a final spot size approximately 15 μm. This could theoretically be improved. The two laser beams are focused via a pair of F/1.2 aspheric lenses onto a double-pass 'clam shell' aspheric mirror system. An analysis of the lens and mirror system is given and compared with an alternative ellipsoidal system already developed. The problems of manufacturing aspheric lenses to operate at 1.06 μm are outlined and an alternative novel approach to this design given. (author)

Ponderomotive force near cyclotron resonance

Energy Technology Data Exchange (ETDEWEB)

Kono, Mitsuo; Sanuki, Heiji

1987-01-01

The ponderomotive force, which is involved in the excitation of macroscopic behaviors of plasma caused by wave motion, plays an important role in various non-linear wave motion phenomena. In the present study, equations for the pondermotive force for plasma in a uniform magnetic field is derived using a renormalization theory which is based on the Vlasov equation. It is shown that the pondermotive force, which diverges at the cyclotron resonence point according to adiabatic approximation, can be expressed by a non-divergent equation by taking into account the instability of the cyclotron orbit due to high-order scattering caused by a wave. This is related with chaotic particle behaviors near cyclotron resonance, where the pondermotive force is small and the diffusion process prevails. It is assumed here that the amplitude of the high-frequency electric field is not large and that the broadening of cyclotron levels is smaller than the distance between the levels. A global chaos will be created if the amplitude of the electric field becomes greater to allow the broadening to exceed the distance between the levels. (Nogami, K.).

Cyclotron transitions of bound ions

Science.gov (United States)

Bezchastnov, Victor G.; Pavlov, George G.

2017-06-01

A charged particle in a magnetic field possesses discrete energy levels associated with particle rotation around the field lines. The radiative transitions between these levels are the well-known cyclotron transitions. We show that a bound complex of particles with a nonzero net charge displays analogous transitions between the states of confined motion of the entire complex in the field. The latter bound-ion cyclotron transitions are affected by a coupling between the collective and internal motions of the complex and, as a result, differ from the transitions of a "reference" bare ion with the same mass and charge. We analyze the cyclotron transitions for complex ions by including the coupling within a rigorous quantum approach. Particular attention is paid to comparison of the transition energies and oscillator strengths to those of the bare ion. Selection rules based on integrals of collective motion are derived for the bound-ion cyclotron transitions analytically, and the perturbation and coupled-channel approaches are developed to study the transitions quantitatively. Representative examples are considered and discussed for positive and negative atomic and cluster ions.

arXiv Cyclotrons: Magnetic Design and Beam Dynamics

CERN Document Server

Zaremba, Simon

Classical, isochronous, and synchro-cyclotrons are introduced. Transverse and longitudinal beam dynamics in these accelerators are covered. The problem of vertical focusing and iscochronism in compact isochronous cyclotrons is treated in some detail. Different methods for isochronization of the cyclotron magnetic field are discussed. The limits of the classical cyclotron are explained. Typical features of the synchro-cyclotron, such as the beam capture problem, stable phase motion, and the extraction problem are discussed. The main design goals for beam injection are explained and special problems related to a central region with an internal ion source are considered. The principle of a Penning ion gauge source is addressed. The issue of vertical focusing in the cyclotron centre is briefly discussed. Several examples of numerical simulations are given. Different methods of (axial) injection are briefly outlined. Different solutions for beam extraction are described. These include the internal target, extracti...

Recent development and progress of IBA cyclotrons

Energy Technology Data Exchange (ETDEWEB)

Kleeven, W., E-mail: Willem.Kleeven@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Abs, M., E-mail: Michel.Abs@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Delvaux, J.L., E-mail: Jean-Luc.Delvaux@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Forton, E., E-mail: Eric.Forton@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Jongen, Y., E-mail: Yves.Jongen@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Medeiros Romao, L., E-mail: Luis.MedeirosRomao@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Nactergal, B., E-mail: Benoit.Nactergal@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Nuttens, V., E-mail: Vincent.Nuttens@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Servais, T., E-mail: Thomas.Servais@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Vanderlinden, T., E-mail: Thierry.Vanderlinden@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Zaremba, S., E-mail: Simon.Zaremba@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium)

2011-12-15

Several cyclotron development projects were recently realized by Ion Beam Applications S.A. (IBA). This contribution presents three of them: (i) the intensity enhancement of the Cyclone 30 cyclotron, a machine mainly used for the production of SPECT isotopes. This project is related with the increased demand for {sup 201}Tl because of the shortage of Mo/Tc generators from nuclear reactors, (ii) development of a new versatile multiple-particle K = 30 isotope-production cyclotron (the Cyclone 30XP) being able to accelerate H{sup -}, D{sup -} and also {alpha}-particles. The {alpha}-beam of this cyclotron will allow the production of new therapeutic isotopes (e.g. {sup 211}At) and (iii) commissioning of the Cyclone 70 cyclotron installed for Arronax in France. This machine is similar to the C30XP but provides higher energy (K = 70) and allows research on new types of medical isotopes.

Synchro-cyclotron

CERN Multimedia

CERN PhotoLab

1972-01-01

The electromagnetic coil which forms the first section of the proton extraction channel in the improved synchro-cyclotron. The photograph shows the positioning gear and the current septum. An extraction efficiency above 50% is expected.

Compact superconducting cyclotron C400 for hadron therapy

Energy Technology Data Exchange (ETDEWEB)

Jongen, Y.; Abs, M.; Blondin, A.; Kleeven, W.; Zaremba, S.; Vandeplassche, D. [IBA, Chemin du Cyclotron 3, B-1348 Louvain-la-Neuve (Belgium); Aleksandrov, V.; Gursky, S.; Karamyshev, O. [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation); Karamysheva, G., E-mail: gkaram@nu.jinr.r [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation); Kazarinov, N.; Kostromin, S.; Morozov, N.; Samsonov, E.; Shirkov, G.; Shevtsov, V.; Syresin, E.; Tuzikov, A. [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation)

2010-12-01

The compact superconducting isochronous cyclotron C400 has been designed by the IBA-JINR collaboration. It will be the first cyclotron in the world capable of delivering protons, carbon and helium ions for cancer treatment. The cyclotron construction is started this year within the framework of the Archade project (Caen, France). {sup 12}C{sup 6+} and {sup 4}He{sup 2+} ions will be accelerated to 400 MeV/uu energy and extracted by the electrostatic deflector, H{sub 2}{sup +} ions will be accelerated to the energy of 265 MeV/uu and extracted by stripping. The magnet yoke has a diameter of 6.6 m, the total weight of the magnet is about 700 t. The designed magnetic field corresponds to 4.5 T in the hills and 2.45 T in the valleys. Superconducting coils will be enclosed in a cryostat; all other parts of the cyclotron will be warm. Three external ion sources will be mounted on the switching magnet on the injection line located below the cyclotron. The main parameters of the cyclotron, its design, the current status of the development work on the cyclotron systems are presented.

Nonlinear Plasma Response to Resonant Magnetic Perturbation in Rutherford Regime

Science.gov (United States)

Zhu, Ping; Yan, Xingting; Huang, Wenlong

2017-10-01

Recently a common analytic relation for both the locked mode and the nonlinear plasma response in the Rutherford regime has been developed based on the steady-state solution to the coupled dynamic system of magnetic island evolution and torque balance equations. The analytic relation predicts the threshold and the island size for the full penetration of resonant magnetic perturbation (RMP). It also rigorously proves a screening effect of the equilibrium toroidal flow. In this work, we test the theory by solving for the nonlinear plasma response to a single-helicity RMP of a circular-shaped limiter tokamak equilibrium with a constant toroidal flow, using the initial-value, full MHD simulation code NIMROD. Time evolution of the parallel flow or ``slip frequency'' profile and its asymptotic approach to steady state obtained from the NIMROD simulations qualitatively agree with the theory predictions. Further comparisons are carried out for the saturated island size, the threshold for full mode penetration, as well as the screening effects of equilibrium toroidal flow in order to understand the physics of nonlinear plasma response in the Rutherford regime. Supported by National Magnetic Confinement Fusion Science Program of China Grants 2014GB124002 and 2015GB101004, the 100 Talent Program of the Chinese Academy of Sciences, and U.S. Department of Energy Grants DE-FG02-86ER53218 and DE-FC02-08ER54975.

Directory of cyclotrons used for radionuclide production in Member States

International Nuclear Information System (INIS)

1998-03-01

The directory of cyclotrons used for radionuclide production is an update of the data base on cyclotrons that was compiled in 1983 by the International Atomic Energy Agency. The directory contains technical, utilization and administrative information supplied to the IAEA as of October 1997. The directory was prepared through information collected by questionnaires sent to institutions that either have a cyclotron, or that were identified to be in the process of installation of a cyclotron. The directory contains 206 entries for cyclotrons operating in 34 Member States. The largest concentration of cyclotrons for radionuclide production are located in the United States of America (66), Japan (33) and Germany (22). The largest number of cyclotrons for a single country is the United States of America. The expansion in number of cyclotrons during the last decade has been driven by the advent of advances in medical imaging instrumentation (PET, SPET and more recently 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons from several companies that manufacture cyclotrons; and recent decisions that 15 O-oxygen PET studies in Japan, and 18 F-FDG PET studies in Germany are eligible for reimbursement by government or insurance companies

Directory of cyclotrons used for radionuclide production in Member States

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

The directory of cyclotrons used for radionuclide production is an update of the data base on cyclotrons that was compiled in 1983 by the International Atomic Energy Agency. The directory contains technical, utilization and administrative information supplied to the IAEA as of October 1997. The directory was prepared through information collected by questionnaires sent to institutions that either have a cyclotron, or that were identified to be in the process of installation of a cyclotron. The directory contains 206 entries for cyclotrons operating in 34 Member States. The largest concentration of cyclotrons for radionuclide production are located in the United States of America (66), Japan (33) and Germany (22). The largest number of cyclotrons for a single country is the United States of America. The expansion in number of cyclotrons during the last decade has been driven by the advent of advances in medical imaging instrumentation (PET, SPET and more recently 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons from several companies that manufacture cyclotrons; and recent decisions that {sup 15}O-oxygen PET studies in Japan, and {sup 18}F-FDG PET studies in Germany are eligible for reimbursement by government or insurance companies.

H-superconducting cyclotron for PET isotope production

International Nuclear Information System (INIS)

Smirnov, V.L.; Vorozhtsov, S.B.; Vincent, J.

2014-01-01

The scientific design of a 14-MeV H - compact superconducting cyclotron for producing of the 18 F and 13 N isotopes has been developed. Main requirements to the facility as a medical accelerator are met in the design. In particular, the main requirement for the cyclotron was the smallest possible size due to the superconducting magnet. The calculations show that the proposed cyclotron allows extracted beam intensity over 500 μA. To increase system reliability and production rates, an external H - ion source is applied. The choice of the cyclotron concept, design of the structure elements, calculation of the electromagnetic fields and beam dynamics from the ion source to the extraction system were performed.

Status report on cyclotron operation

International Nuclear Information System (INIS)

Kovacs, P.; Szuecs, I.; Ander, I.; Lakatos, T.; Fenyvesi, A.; Ditroi, F.; Takacs, S.; Tarkanyi, F.

2004-01-01

The operation of the cyclotron in 2003 was again concentrated to 9 months; January, July and August were reserved for maintenance, renewal works and holidays. The overall working time of the accelerator was 4051 hours. The cyclotron was available for users for 3682 hours. In order to improve the circumstances of the irradiations renewal and improvements were done. (N.T.)

Slow wave cyclotron maser

International Nuclear Information System (INIS)

Kho, T.H.; Lin, A.T.

1988-01-01

Cyclotron masers such as Gyrotrons and the Autoresonance Masers, are fast wave devices: the electromagnetic wave's phase velocity v rho , is greater than the electron beam velocity, v b . To be able to convert the beam kinetic energy into radiation in these devices the beam must have an initial transverse momentum, usually obtained by propagating the beam through a transverse wiggler magnet, or along a nonuniform guide magnetic field before entry into the interaction region. Either process introduces a significant amount of thermal spread in the beam which degrades the performance of the maser. However, if the wave phase velocity v rho v b , the beam kinetic energy can be converted directly into radiation without the requirement of an initial transverse beam momentum, making a slow wave cyclotron maser a potentially simpler and more compact device. The authors present the linear and nonlinear physics of the slow wave cyclotron maser and examine its potential for practical application

A national medical cyclotron facility: report to the Minister of Health by the Medical Cyclotron Committee

International Nuclear Information System (INIS)

1985-01-01

Research and training in nuclear medicine in Australia are both limited by the lack of a medical cyclotron facility. The Committee recommends the establishment of a national medical cyclotron to provide a supply of short-lived radioisotopes for research in relevant fields of medicine, and for diagnostic use in nuclear medicine

Radiation shielding and health physics instrumentation for PET medical cyclotrons

International Nuclear Information System (INIS)

Mukherjee, B.

2002-01-01

Full text: Modern Medical Cyclotrons produce a variety of short-lived positron emitting PET radioisotopes, and as a result are the source of intense neutron and gamma radiations. Since such cyclotrons are housed within hospitals or medical clinics, there is significant potential for un-intentional exposure to staff or patients in proximity to cyclotron facilities. Consequently, the radiological hazards associated with Cyclotrons provide the impetus for an effective radiological shielding and continuous monitoring of various radiation levels in the cyclotron environment. Management of radiological hazards is of paramount importance for the safe operation of a Medical Cyclotron facility. This work summarised the methods of shielding calculations for a compact hospital based Medical Cyclotron currently operating in Canada, USA and Australia. The design principle and operational history of a real-time health physics monitoring system (Watchdog) operating at a large multi-energy Medical Cyclotron is also highlighted

Development of cyclotron solid targetry

International Nuclear Information System (INIS)

D'Souza, J.; Deans, T.; Cryer, D.; Price, R.

2004-01-01

Full text: Western Australia's first medical cyclotron was recently installed in the Department of Medical Technology and Physics at Sir Charles Gairdner Hospital. The cyclotron is routinely used for 18 F production using a liquid target, and now research is being undertaken into solid target bombardment for production of novel isotopes such as 124 I, 64 Cu and 96 Tc. The IBA Cyclone 18/9 has a maximum proton beam energy of 18MeV and maximum beam current of 80μA. A proton beam is generated by the acceleration of H- ions in the evacuated cyclotron (10 -6 bar) which are then stripped of 2 electrons just prior to exiting a target port. Each port has two strippers which are made of 10μm thick carbon with dimensions 12mmxl3mm. Due to their thinness, the strippers are easily ruptured. The Cyclone 18/9 has 8 target ports. In order to fit a target onto the cyclotron when the cyclotron is already evacuated the target is first evacuated to 10 -3 bar by a roughing pump before an isolation valve at the port is opened. This stops any damage that may occur by the flow of air from the target reservoir to the cyclotron eg to the strippers. The first step in the project to develop solid targetry is to build a beam line in order to measure the beam profile. If successful, this design will be improved in order to have a beam line and target holder that are suitable for use in solid target bombardment. A 40cm beam line with an internal diameter of 3.6cm was built to fit onto the IBA Cyclone 18/9. The beam line, made out of aluminium, incorporates a step 5cm from the end at which a target material can be fitted. A cover fits onto the beam line, behind the target in order to maintain vacuum. The cover is held in place by the vacuum within the beam line. At the end of bombardment, the beam line can be isolated from the vacuum of the target and normal air pressure restored. In doing so the cover plate falls open and the target falls into a lead pot, ready for removal from the cyclotron

CERN celebrates the ‘Rutherford centenary’

CERN Document Server

Maximilien Brice

2011-01-01

CERN marked the centenary of the discovery of the atomic nucleus, as published in Ernest Rutherford’s famous paper of 1911, with its Rutherford Centennial Colloquium, held on 15 November in the presence of John Adank, New Zealand’s ambassador to the World Trade Organization in Geneva. After an introduction by CERN’s director-general, Rolf Heuer, the speakers covered topics ranging from Rutherford’s early life in New Zealand, presented by his great grand-daughter Mary Fowler, through to his role as an inspiration to young scientists in his homeland, as seen by New Zealander Mark Kruse, who is now at Duke University and a member of the ATLAS collaboration. Fellow New Zealander, John Campbell, spoke about Rutherford’s road to discovery of the nuclear atom. Rutherford’s scientific legacy in nuclear physics was covered by Sean Freeman, appropriately from Manchester University, where the famous scattering experiment took place. Jerome Friedman delved deeper into matter with his talk detailing the scatt...

Decontamination of the activation product based on a legal revision of the cyclotron vault room on the non-self-shield compact medical cyclotron

International Nuclear Information System (INIS)

Komiya, Isao; Umezu, Yoshiyuki; Fujibuchi, Toshiou; Nakamura, Kazumasa; Baba, Shingo; Honda, Hiroshi

2016-01-01

The non-self-shield compact medical cyclotron and the cyclotron vault room were in operation for 27 years. They have now been decommissioned. We efficiently implemented a technique to identify an activation product in the cyclotron vault room. Firstly, the distribution of radioactive concentrations in the concrete of the cyclotron vault room was estimated by calculation from the record of the cyclotron operation. Secondly, the comparison of calculated results with an actual measurement was performed using a NaI scintillation survey meter and a high-purity germanium detector. The calculated values were overestimated as compared to the values measured using the Nal scintillation survey meter and the high-purity germanium detector. However, it could limit the decontamination area. By simulating the activation range, we were able to minimize the concrete core sampling. Finally, the appropriate range of radioactivated area in the cyclotron vault room was decontaminated based on the results of the calculation. After decontamination, the radioactive concentration was below the detection limit value in all areas inside the cyclotron vault room. By these procedures, the decommissioning process of the cyclotron vault room was more efficiently performed. (author)

Near-surface analysis with nuclear reactions and scattering

International Nuclear Information System (INIS)

Dunning, K.L.; Hirvonen, J.K.

1974-01-01

Very useful information about the elemental composition of solids in the surface and near-surface regions can be obtained with small accelerators and suitable auxiliary apparatus. Two methods which produce data from which quantitative concentration depth profiles can be constructed and which have been used extensively at this laboratory are: nuclear resonance profiling and Rutherford backscattering. The first method is described in detail. Data are given on profiles of Al and Al + Na films implanted on silicon substrates. Rutherford backscattering spectra for chromium implanted into silicon dioxide are used to illustrate the improved depth sensitivity that can be obtained with a magnetic spectrometer in depth concentration profiles of heavy impurities relative to that obtainable with a conventional semiconductor detector

Rf structure of superconducting cyclotron for therapy application

International Nuclear Information System (INIS)

Takekoshi, Hidekuni; Matsuki, Seishi; Mashiko, Katuo; Shikazono, Naomoto.

1981-01-01

Advantages of fast neutrons in therapeutical application are now widely recognized. Fast neutrons are generated by bombarding a thick beryllium target with high energy protons and deuterons. The AVF cyclotrons which deliver 50 MeV protons and 25 MeV deuterons are commonly used and are commercially available now. At the treatment usually rotational irradiation is taken to prevent an injury to normal tissue from the high LET effect of fast neutrons. The construction cost of both cyclotrons and isocentric irradiation installation are relatively high, so that the spread of neutron therapy is obstructed. A superconducting cyclotron for neutron therapy application was proposed by a Chalk River group. This low cost design allows the installation to be a dedicated facility located in a hospital, and small size allows installations of the complete cyclotron in a rotatable gantry. The design studies of the superconducting cyclotron based on this idea are going on at Kyoto University. The full scale model experiments for a rf structure of the cyclotron were carried out. (author)

Commissioning of cryogen delivery system for superconducting cyclotron magnet

International Nuclear Information System (INIS)

Pal, G.; Nandi, C.; Bhattacharyya, T.K.; Chaudhuri, J.; Bhandari, R.K.

2005-01-01

A K-500 superconducting cyclotron is being constructed at VECC Kolkata. The cryogen delivery system distributes liquid helium and liquid nitrogen to the superconducting cyclotron. Liquid helium is required to cool the cyclotron magnet and cryopanels. Liquid nitrogen is used to reduce the capacity of the helium liquefier. This paper describes the system, the current status and the commissioning experiences of cryogen delivery system for cyclotron magnet. (author)

Progress report: Variable Energy Cyclotron Centre, Calcutta

International Nuclear Information System (INIS)

1999-01-01

This volume of the progress report brings out the scientific and technical activities of Variable Energy Cyclotron Centre, Calcutta during the year 1999. This includes brief review of the various R and D activities of the Centre and outside users of the cyclotron from the universities and other research institutes. The operational activities of the cyclotron with ECR ion sources, accelerator oriented research activities, activities on detector, target and electronics are reported. The activities of the Computer and Informatics group are described. The status report of the ongoing projects is also provided. The main activities of the superconducting cyclotron project, radioactive ion beam project, heavy ion experimental facility, advanced computational facility, recovery and analysis of helium from hot springs and material science research are described

10 GHz ECRIS for Warsaw Cyclotron

CERN Document Server

Sudlitz, K

1999-01-01

Cusp type, 10 GHz ECRIS has been built and tested earlier. For obtaining intensive beams, more relevant for cyclotron, cusp geometry has been replaced by hexapole. Discharge chamber (stainless steel, 50 mm diameter, 250 mm long) is an extension of a coaxial line, feeding RF (9,6 GHz, up to 200 W) to the plasma. The NdFeB hexapole (0,52 T on the surface) has been used. The axial magnetic field is created by water cooled coils. The axial injection line dedicated to K160 isochronous heavy ion cyclotron has been constructed. The line consists of Glaser lenses, double focusing magnet, solenoid and mirror type inflector. The system provides sufficient transmission of the beam from ECR ion source to the firsts orbits of the cyclotron for m/q ranging from 7 to 2. After successful initial tests which were done in July 1997 the ECRIS serves as an external source for Warsaw Cyclotron.

Relating P-band AIRSAR backscatter to forest stand parameters

Science.gov (United States)

Wang, Yong; Melack, John M.; Davis, Frank W.; Kasischke, Eric S.; Christensen, Norman L., Jr.

1993-01-01

As part of research on forest ecosystems, the Jet Propulsion Laboratory (JPL) and collaborating research teams have conducted multi-season airborne synthetic aperture radar (AIRSAR) experiments in three forest ecosystems including temperate pine forest (Duke, Forest, North Carolina), boreal forest (Bonanza Creek Experimental Forest, Alaska), and northern mixed hardwood-conifer forest (Michigan Biological Station, Michigan). The major research goals were to improve understanding of the relationships between radar backscatter and phenological variables (e.g. stand density, tree size, etc.), to improve radar backscatter models of tree canopy properties, and to develop a radar-based scheme for monitoring forest phenological changes. In September 1989, AIRSAR backscatter data were acquired over the Duke Forest. As the aboveground biomass of the loblolly pine forest stands at Duke Forest increased, the SAR backscatter at C-, L-, and P-bands increased and saturated at different biomass levels for the C-band, L-band, and P-band data. We only use the P-band backscatter data and ground measurements here to study the relationships between the backscatter and stand density, the backscatter and mean trunk dbh (diameter at breast height) of trees in the stands, and the backscatter and stand basal area.

Electron cyclotron harmonic wave acceleration

Science.gov (United States)

Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

1987-01-01

A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

Electron cyclotron harmonic wave acceleration

International Nuclear Information System (INIS)

Karimabadi, H.; Menyuk, C.R.; Sprangle, P.; Vlahos, L.; Salonika Univ., Greece)

1987-01-01

A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts. 31 references

83-inch cyclotron research program. Final report

International Nuclear Information System (INIS)

Parkinson, W.C.

1983-07-01

In June of 1960 the US Atomic Energy Commission authorized the construction of a modern variable energy cyclotron facility at The University of Michigan to be used for research in nuclear spectroscopy. The Legislature of the State of Michigan made available funds for construction of a building to house the 83-inch cyclotron and auxiliary equipment as well as the University's remodeled 42-inch cyclotron. The research program centered around the 83-inch cyclotron was funded by the AEC and its successors, the Energy Research and Development Administration (ERDA) and the Department of Energy (DOE), from September 1964 through March 1977. The program represented a continuation of the research effort using the 42-inch cyclotron facility which had been supported continuously by the AEC since February 1950. This final report to DOE briefly describes the research facility, the research program, and highlights the principal accomplishments of the effort. It begins with a historical note to place this effort within the context of nuclear physics research in the Department of Physics of the University of Michigan

Recycling and recommissioning a used biomedical cyclotron

International Nuclear Information System (INIS)

Carroll, L.R.; Ramsey, F.; Armbruster, J.; Montenero, M.

2001-01-01

Biomedical Cyclotrons have a very long life, but there eventually comes a time when any piece of equipment has to be retired from service. From time to time, we have the opportunity to help find new homes for used cyclotrons which, with relatively modest overhaul and refurbishment, can have many additional years of productive service, and thus represent a very valuable asset. The reasons for retiring a cyclotron vary, of course, but in our experience it is often due to an institution's changing priorities or changing needs, rather than the due to any fundamental age-related deficiency in the cyclotron itself. In this paper we will report on the relocation and successful restoration of a used TCC CP-42 cyclotron, which was moved from M.D. Anderson Hospital in Houston to Denton, Texas in early 1998, where it is presently being used for R and D and commercial production of biomedical isotopes. Ownership of the machine has been transferred to the University of North Texas; facility, manpower, and operational resources are provided by International Isotopes, Inc

Diagnostic system for the nuclear medicine with baby cyclotron

International Nuclear Information System (INIS)

Kashihara, Masao; Wakasa, Shyuichiro

1982-01-01

The system of cyclotron nuclear medicine consists of ''RI-production by using the cyclotron'', ''production of radio-pharmaceuticals labeled with RI'', ''positron tomography''. On the other hand, Ultra compact cyclotron (Baby cyclotron) itself, RI production technique and positron tomography have been rapidly developed and advanced. We think that these three functions must be balance in the development in order to spread this system into the routine work in the hospital. However, since the technology of the synthesis for the labeled compounds is not so developed so far, more advance can be strongly expected. In this report, construction of the cyclotron nuclear medicine, utility for the practical use of RI produced by using the cyclotron, technique of RI production, and the studies on automated and efficient productions of radio-pharmaceuticals labeled with short-lived positron emitters for medical diagnostic use are described. (author)

Development of a Medical Cyclotron Production Facility

Science.gov (United States)

Allen, Danny R.

2003-08-01

Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short-lived isotopes.

Development of a Medical Cyclotron Production Facility

International Nuclear Information System (INIS)

Allen, Danny R.

2003-01-01

Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short-lived isotopes

Method and apparatuses for ion cyclotron spectrometry

Science.gov (United States)

Dahl, David A [Idaho Falls, ID; Scott, Jill R [Idaho Falls, ID; McJunkin, Timothy R [Idaho Falls, ID

2012-03-06

An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber. The trapping electric field may comprise a field potential that, when taken in cross-section along the z-axis, includes at least one section that is concave down and at least one section that is concave up so that ions traversing the field potential experience a net magnetron effect on a cyclotron frequency of the ions that is substantially equal to zero. Other apparatuses and a method for performing ion cyclotron spectrometry are also disclosed herein.

Cyclotron radiation by a multi-group method

International Nuclear Information System (INIS)

Chu, T.C.

1980-01-01

A multi-energy group technique is developed to study conditions under which cyclotron radiation emission can shift a Maxwellian electron distribution into a non-Maxwellian; and if the electron distribution is non-Maxwellian, to study the rate of cyclotron radiation emission as compared to that emitted by a Maxwellian having the same mean electron density and energy. The assumptions in this study are: the electrons should be in an isotropic medium and the magnetic field should be uniform. The multi-group technique is coupled into a multi-group Fokker-Planck computer code to study electron behavior under the influence of cyclotron radiation emission in a self-consistent fashion. Several non-Maxwellian distributions were simulated to compare their cyclotron emissions with the corresponding energy and number density equivalent Maxwellian distribtions

Low energy cyclotron for radiocarbon dating

International Nuclear Information System (INIS)

Welch, J.J.

1984-12-01

The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity 14 C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate 14 C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect 14 C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible

Stimulated Raman backscattering at high laser intensities

Energy Technology Data Exchange (ETDEWEB)

Skoric, M M [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia); Tajima, Toshiki; Sasaki, Akira; Maluckov, A; Jovanovic, M

1998-03-01

Signatures of Stimulated Raman backscattering of a short-pulse high-intensity laser interacting with an underdense plasma are discussed. We introduce a nonlinear three-wave interaction model that accounts for laser pump depletion and relativistic detuning. A mechanism is revealed based on a generic route to chaos, that predicts a progressive increase of the backscatter complexity with a growing laser intensity. Importance of kinetic effects is outlined and demonstrated in fluid-hybrid and particle simulations. As an application, we show that spectral anomalies of the backscatter, predicted by the above model, are consistent with recent sub-picosecond, high-intensity laser gas-target measurements at Livermore and elsewhere. Finally, a recently proposed scheme for generation of ultra-short, low-prepulse laser pulses by Raman backscattering in a thin foil target, is shown. (author)

PIXE analysis by baby cyclotron

International Nuclear Information System (INIS)

Yoshida, Hyogo; Tanaka, Teruaki; Ito, Takashi; Toda, Yohjiro; Wakasa, Hideichiro

1988-01-01

The Japan Steel Works, Ltd. has been supplying a very small sized cyclotron (Baby Cyclotron) to hospitals and research facilities. The cyclotron is designed to produce short-lived radioisotopes for medical use. In the present study, this cyclotron is modified so that it can serve for PIXE analysis. The PIXE (particle induced X-ray emission) technique has the following features: (1) Down to 1 ng of trace material in a sample (mg - μg) can be detected, (2) An analysis run is completed in one to ten minutes, permitting economical analysis for a large number of samples, (3) Several elements can be analyzed simultaneously, with an almost constant sensitivity for a variety of elements ranging from aluminum to heavy metals, (4) Analysis can be performed nondestructively without a chemical process, and (5) The use of microbeam can provide data on the distribution of elements with a resolution of several μm. Software for analysis is developed to allow the modified equipment to perform peak search, background fitting, and identification and determination of peaks. A study is now being conducted to examine the performance of the equipment for PIXE analysis of thin samples. Satisfactory results have been obtained. The analysis time, excluding the background correction, is 5-10 min. (Nogami, K.)

Understanding the radar backscattering from flooded and nonflooded Amazonian forests: results from canopy backscatter modeling

International Nuclear Information System (INIS)

Wang, Y.; Hess, L.L.; Filoso, S.; Melack, J.M.

1995-01-01

To understand the potential of using multiwavelength imaging radars to detect flooding in Amazonian floodplain forests, we simulated the radar backscatter from a floodplain forest with a flooded or nonflooded ground condition at C-, L-, and P-bands. Field measurements of forest structure in the Anavilhanas archipelago of the Negro River, Brazil, were used as inputs to the model. Given the same wavelength or incidence angle, the ratio of backscatter from the flooded forest to that from the nonflooded forest was higher at HH polarization than at VV polarization. Given the same wavelength or polarization, the ratio was larger at small incidence angles than at large incidence angles. Given the same polarization or incidence angle, the ratio was larger at a long wavelength than at a short wavelength. As the surface soil moisture underneath the nonflooded forest increased from 10% to 50% of volumetric moisture, the flooded/nonflooded backscatter ratio decreased; the decreases were small at C- and L-band but large at P-band. When the leaf size was comparable to or larger than the wavelength of C-band, the leaf area index (LAI) had a large effect on the simulated C-band (not L-band or P-band) backscatter from the flooded and nonflooded forests. (author)

Operation of the Karlsruhe Isochronous Cyclotron in 1975

International Nuclear Information System (INIS)

Schulz, F.; Schweickert, H.

1976-06-01

The operation of the Karlsruhe Isochronous Cyclotron in 1975 is briefly surveyed. The main reasons for a very short period for maintenance, repair and installation, and several additional efforts to improve the reliability of the accelerator installation, are discussed. The status and the results of several technical developments for the cyclotron are described: 1) the axial injection system; 2) computer aided cyclotron operation; 3) ion source development; 4) capacitive current measurement at the external beam; 5) new correction coils for the cyclotron; 6) improvement of the neutron time-of-flight spectrometer. As there is an increasing interest in using this type of accelerator for research in fields other than nuclear physics, it was felt appropriate to present short surveys on investigations at our cyclotron in 1975 in the fields of: 1) solid state physics; 2) engineering; 3) materials research; 4) nuclear medicine; 5) nuclear chemistry. (orig.) [de

Nodule bottom backscattering study using multibeam echosounder

Digital Repository Service at National Institute of Oceanography (India)

Chakraborty, B.; Raju, Y.S.N.; Nair, R.R.

A study is carried out to observe the angular dependence of backscattering strength at nodule area where grab sample and photographic data is available. Theoretical study along with the experimentally observed data shows that the backscattering...

Present and future superconducting cyclotrons

International Nuclear Information System (INIS)

Nolen, J.A. Jr.

1987-01-01

This paper begins with a brief review of the status of present superconducting (SC) cyclotron projects, including the two which are currently operating and the six which are under construction. The next section summarizes the main features shared by five of these machines, while the third section presents recent developments and new concepts introduced in the other three ''second generation'' SC cyclotrons. Projects in early stages of development are discussed in the fourth section

NIRS-Chiba isochronous cyclotron 1975

International Nuclear Information System (INIS)

Ogawa, H.; Kumamoto, Y.; Yamada, T.; Hiramoto, T.

1976-02-01

The cyclotron facility installed according to the recommendation of the Atomic Energy Committee of Japan is used for neutron therapy and production of short-lived radioisotopes. Construction on the facility was started in the autumn of 1972, and completed in March 1974. Described are the following: beam transport and the experimental hall, machine research and improvement, machine time sharing and the particles and energies, characteristics of the cyclotron, and facility personnel. (auth.)

Knowledge based operation assist system for JAERI AVF cyclotron

International Nuclear Information System (INIS)

Agematsu, T.; Okumura, S.; Yokota, W.; Arakawa, K.; Murakami, T.; Okamura, T.

1992-01-01

We have developed two operation assist systems for easy and rapid operation of the JAERI AVF cyclotron. One is a knowledge based expert system guiding the sequence of parameter adjustment to inexperienced cyclotron operators. The other is a real-time simulation of the beam trajectories which are calculated from actual operating parameters. It graphically indicates feasible setting range of parameters that satisfies the acceptance of the cyclotron. These systems provide a human interface to adjust the parameters of the cyclotron. (author)

An Ultrasonic Backscatter Instrument for Cancellous Bone Evaluation in Neonates

Directory of Open Access Journals (Sweden)

Chengcheng Liu

2015-09-01

Full Text Available Ultrasonic backscatter technique has shown promise as a noninvasive cancellous bone assessment tool. A novel ultrasonic backscatter bone diagnostic (UBBD instrument and an in vivo application for neonatal bone evaluation are introduced in this study. The UBBD provides several advantages, including noninvasiveness, non-ionizing radiation, portability, and simplicity. In this study, the backscatter signal could be measured within 5 s using the UBBD. Ultrasonic backscatter measurements were performed on 467 neonates (268 males and 199 females at the left calcaneus. The backscatter signal was measured at a central frequency of 3.5 MHz. The delay (T1 and duration (T2 of the backscatter signal of interest (SOI were varied, and the apparent integrated backscatter (AIB, frequency slope of apparent backscatter (FSAB, zero frequency intercept of apparent backscatter (FIAB, and spectral centroid shift (SCS were calculated. The results showed that the SOI selection had a direct influence on cancellous bone evaluation. The AIB and FIAB were positively correlated with the gestational age (|R| up to 0.45, P10 µs. Moderate positive correlations (|R| up to 0.45, P10 µs. The T2 mainly introduced fluctuations in the observed correlation coefficients. The moderate correlations observed with UBBD demonstrate the feasibility of using the backscatter signal to evaluate neonatal bone status. This study also proposes an explicit standard for in vivo SOI selection and neonatal cancellous bone assessment.

Isochronous cyclotron for thermonuclear reactors driving

International Nuclear Information System (INIS)

Alenitskij, Yu.G.

1998-01-01

The main requirements to an accelerator as a part of an electronuclear power plant are considered. The range of the parameters of the accelerated proton and deuteron beams, for which the isochronous cyclotron is the most profitable, is proposed. An opportunity of using the cyclotron to drive the research reactors of various types is considered

"Rutherford's Experiment" on Alpha Particles Scattering: The Experiment That Never Was

Science.gov (United States)

Leone, M.; Robotti, N.; Verna, G.

2018-01-01

The so-called "Rutherford's experiment," as it is outlined in many physics textbooks, is a case in point of the flaws around the history at the educational level of one of the decisive event of modern physics: the discovery that the atom has a nucleus. This paper shows that this alleged experiment is a very approximate and very partial…

3D Backscatter Imaging System

Science.gov (United States)

Whitaker, Ross (Inventor); Turner, D. Clark (Inventor)

2016-01-01

Systems and methods for imaging an object using backscattered radiation are described. The imaging system comprises both a radiation source for irradiating an object that is rotationally movable about the object, and a detector for detecting backscattered radiation from the object that can be disposed on substantially the same side of the object as the source and which can be rotationally movable about the object. The detector can be separated into multiple detector segments with each segment having a single line of sight projection through the object and so detects radiation along that line of sight. Thus, each detector segment can isolate the desired component of the backscattered radiation. By moving independently of each other about the object, the source and detector can collect multiple images of the object at different angles of rotation and generate a three dimensional reconstruction of the object. Other embodiments are described.

Cyclotron to Oslo University

International Nuclear Information System (INIS)

Sandstad, J.

1978-01-01

The new cyclotron was delivered to Oslo University on September 21st 1978, and was mannfactured by A/B Scandtronix of Uppsala, Sweden. The contract price was 6,8 million Norwegian kroner and installation will cost a further 4 million. The main specifications are given. The energy will be 36 MeV for protons and alpha particles, 18 MeV deuterons and 48 MeV for helium 3. The principle of a cyclotron is briefly described. While the primary purpose of the machine is nuclear research it is also planned to produce short-lived radioisotopes, primarily iodine 123. (JIW)

New superconducting cyclotron driven scanning proton therapy systems

International Nuclear Information System (INIS)

Klein, Hans-Udo; Baumgarten, Christian; Geisler, Andreas; Heese, Juergen; Hobl, Achim; Krischel, Detlef; Schillo, Michael; Schmidt, Stefan; Timmer, Jan

2005-01-01

Since one and a half decades ACCEL is investing in development and engineering of state of the art particle-therapy systems. A new medical superconducting 250 MeV proton cyclotron with special focus on the present and future beam requirements of fast scanning treatment systems has been designed. The first new ACCEL medical proton cyclotron is under commissioning at PSI for their PROSCAN proton therapy facility having undergone successful factory tests especially of the closed loop cryomagnetic system. The second cyclotron is part of ACCEL's integrated proton therapy system for Europe's first clinical center, RPTC in Munich. The cyclotron, the energy selection system, the beamline as well as the four gantries and patient positioners have been installed. The scanning system and major parts of the control software have already been tested. We will report on the concept of ACCEL's superconducting cyclotron driven scanning proton therapy systems and the current status of the commissioning work at PSI and RPTC

Cyclotron for industrial production of radioisotopes: relevants characteristics

International Nuclear Information System (INIS)

Lima, Wanderley de

1997-01-01

The industrial production of radioisotopes requests cyclotrons with easy maintenance services, high productivity and low operation costs. To obtain this performance the experts on the have achieved excellent results, taking advantage of modern resources in calculation and modeling. Only by the maximum exploitation of the azimutal variation of the magnetic field, a physical concept introduced in 1967 with the isocronous cyclotrons, it was possible to construct cyclotrons with only 30% of the electrical consumption required by the former cyclotrons. On the other hand, the acceleration of negative ions enable the 100% accelerated beam utilization, without internal energy dissipation, obtaining beam intensities up to 1mA in continuous running which represents an increased factor of 15. Other construction parameters were optimized aiming at reliability and reduction in the components activation. Concerning energy consumption and the beam intensity supplied, a present cyclotron with 30 MeV and 300μA of protons current is 15 times more efficient than its precedent. (author). 6 refs., 1 fig., 2 tabs

Feasibility study of Nb3Al Rutherford cable for high field accelerator magnet application

Energy Technology Data Exchange (ETDEWEB)

Yamada, R.; /Fermilab; Kikuchi, A.; /Tsukuba Magnet Lab.; Ambrosio, G.; Andreev, N.; Barzi, E.; Cooper, C.; Feher, S.; Kashikhin, V.V.; Lamm, M.; Novitski, I.; /Fermilab; Takeuchi, T.; /Tsukuba Magnet Lab.; Tartaglia, M.; Turrioni, D.; /Fermilab; Verweij, A.P.; /CERN; Wake, M.; Willering, G; /Tsukuba Magnet Lab.; Zlobin, A.V.; /Fermilab

2006-08-01

Feasibility study of Cu stabilized Nb{sub 3}Al strand and Rutherford cable for the application to high field accelerator magnets are being done at Fermilab in collaboration with NIMS. The Nb{sub 3}Al strand, which was developed and manufactured at NIMS in Japan, has a non-copper Jc of about 844 A/mm{sup 2} at 15 Tesla at 4.2 K, a copper content of 50%, and filament size of about 50 microns. Rutherford cables with 27 Nb{sub 3}Al strands of 1.03 mm diameter were fabricated and tested. Quench tests on a short cable were done to study its stability with only its self field, utilizing a high current transformer. A pair of 2 meter long Nb{sub 3}Al cables was tested extensively at CERN at 4.3 and 1.9 K up to 11 Tesla including its self field with a high transport current of 20.2 kA. In the low field test we observed instability near splices and in the central region. This is related to the flux-jump like behavior, because of excessive amount of Nb in the Nb{sub 3}Al strand. There is possibility that the Nb in Nb{sub 3}Al can cause instability below 2 Tesla field regions. We need further investigation on this problem. Above 8 Tesla, we observed quenches near the critical surface at fast ramp rate from 1000 to 3000 A/sec, with quench velocity over 100 m/sec. A small racetrack magnet was made using a 14 m of Rutherford cable and successfully tested up to 21.8 kA, corresponding to 8.7 T.

Interlinking backscatter, grain size and benthic community structure

Science.gov (United States)

McGonigle, Chris; Collier, Jenny S.

2014-06-01

The relationship between acoustic backscatter, sediment grain size and benthic community structure is examined using three different quantitative methods, covering image- and angular response-based approaches. Multibeam time-series backscatter (300 kHz) data acquired in 2008 off the coast of East Anglia (UK) are compared with grain size properties, macrofaunal abundance and biomass from 130 Hamon and 16 Clamshell grab samples. Three predictive methods are used: 1) image-based (mean backscatter intensity); 2) angular response-based (predicted mean grain size), and 3) image-based (1st principal component and classification) from Quester Tangent Corporation Multiview software. Relationships between grain size and backscatter are explored using linear regression. Differences in grain size and benthic community structure between acoustically defined groups are examined using ANOVA and PERMANOVA+. Results for the Hamon grab stations indicate significant correlations between measured mean grain size and mean backscatter intensity, angular response predicted mean grain size, and 1st principal component of QTC analysis (all p PERMANOVA for the Hamon abundance shows benthic community structure was significantly different between acoustic groups for all methods (p ≤ 0.001). Overall these results show considerable promise in that more than 60% of the variance in the mean grain size of the Clamshell grab samples can be explained by mean backscatter or acoustically-predicted grain size. These results show that there is significant predictive capacity for sediment characteristics from multibeam backscatter and that these acoustic classifications can have ecological validity.

Present situation of 'baby cyclotron'

International Nuclear Information System (INIS)

Yamada, Teruo

1981-01-01

A ''baby cyclotron'' has been developed by the Japan Steel Works, Ltd. Its No. 1 model (proton 9.4 MeV) was delivered to the Nakano Hospital of National Sanatorium in March, 1979. It is being used successfully for the production of 11 C, 13 N and 15 O and labeled compounds. The proton or deuteron particles accelerated in the cyclotron collide on target materials. The target box, which is automatically changeable, is directly installed to the accelerating box, thereby taking the safety measures for any leaking radiation. The following matters are described: the production of short-lived radioisotopes (RI yields and treatment); the processes of production in the Nakano Hospital, with No. 1 baby cyclotron, including the photosynthesis of labeled compounds such as 11 C-labeled glucose; the research on the automation in the synthesis of organic labeled compounds like 11 C-palmitic acid. (J.P.N.)

Cryogenic system for VECC K500 superconducting cyclotron

CERN Document Server

Pal, G; Bhattacharyya, T K; Bhandari, R K

2009-01-01

VEC Centre, Kolkata in India is at an advanced stage of commissioning a K500 superconducting cyclotron. The superconducting coil of the magnet for cyclotron is cooled by liquid helium. Three liquid helium cooled cryopanels, placed inside the Dees of the radiofrequency system, maintain the vacuum in the acceleration region of the superconducting cyclotron. The cryogenic system for magnet for cyclotron has been tested by cooling the coil and energizing the magnet. The cryogenic system for cryopanels has also been tested. Heater and temperature sensor were placed on the liquid helium cold head for cryopanel. The temperature of the cold head was observed to be below 20 K upto a heat load of 11.7 watt.

X-ray backscatter imaging with a spiral scanner

International Nuclear Information System (INIS)

Bossi, R.H.; Cline, J.L.; Friddell, K.D.

1989-01-01

X-ray backscatter imaging allows radiographic inspections to be performed with access to only one side of the object. A collimated beam of radiation striking an object will scatter x-rays by Compton scatter and x-ray fluorescence. A detector located on the source side of the part will measure the backscatter signal. By plotting signal strength as gray scale intensity vs. beam position on the object, an image of the object can be constructed. A novel approach to the motion of the collimated incident beam is a spiral scanner. The spiral scanner approach, described in this paper, can image an area of an object without the synchronized motion of the object or detector, required by other backscatter imaging techniques. X-ray backscatter is particularly useful for flaw detection in light element materials such as composites. The ease of operation and the ability to operate non-contact from one side of an object make x-ray backscatter imaging of increasing interest to industrial inspection problems

On line ultrasonic integrated backscatter

International Nuclear Information System (INIS)

Landini, L.; Picano, E.; Mazzarisi, A.; Santarelli, F.; Benassi, A.; De Pieri, G.

1988-01-01

A new equipment for on-line evaluation of index based on two-dimensional integrated backscatter from ultrasonic images is described. The new equipment is fully integrated into a B-mode ultrasonic apparatus which provides a simultaneous display of conventional information together with parameters of tissue characterization. The system has been tested with a backscattering model of microbubbles in polysaccharide solution, characterized by a physiological exponential time decay. An exponential fitting to the experimental data was performed which yielded r=0.95

Variable-Energy Cyclotron for Proton Therapy Application

CERN Document Server

Alenitsky, Yu G; Vorozhtsov, A S; Glazov, A A; Mytsyn, G V; Molokanov, A G; Onishchenko, L M

2004-01-01

The requirements to characteristics of the beams used for proton therapy are considered. The operation and proposed cyclotrons for proton therapy are briefly described. The technical decisions of creation of the cyclotron with energy variation in the range 70-230 MeV and with current up to 100 nA are estimated. Taking into account the fact, that the size and cost of the cyclotron are approximately determined by the maximum proton energy, it is realistically offered to limit the maximum proton energy to 190 MeV and to elaborate a cyclotron project with a warm winding of the magnet for acceleration of H^{-} ions. The energy of the extracted protons for each run is determined by a stripped target radius in the vacuum chamber of the accelerator, and the radiation dose field for the patient is created by the external devices using the developed techniques.

Backscattering at a pulsed neutron source, the MUSICAL instrument

International Nuclear Information System (INIS)

Alefeld, B.

1995-01-01

In the first part the principles of the neutron backscattering method are described and some simple considerations about the energy resolution and the intensity are presented. A prototype of a backscattering instrument, the first Juelich instrument, is explained in some detail and a representative measurement is shown which was performed on the backscattering instrument IN10 at the ILL in Grenoble. In the second part a backscattering instrument designed for a pulsed neutron source is proposed. It is shown that a rather simple modification, which consists in the replacement of the Doppler drive of the conventional backscattering instrument by a multi silicon monochromator crystal (MUSICAL) leads to a very effective instrument, benefitting from the peak flux of the pulsed source. ((orig.))

Super-virtual Interferometric Separation and Enhancement of Back-scattered Surface Waves

KAUST Repository

Guo, Bowen

2015-08-19

Back-scattered surface waves can be migrated to detect near-surface reflectors with steep dips. A robust surface-wave migration requires the prior separation of the back-scattered surface-wave events from the data. This separation is often difficult to implement because the back-scattered surface waves are masked by the incident surface waves. We mitigate this problem by using a super-virtual interferometric method to enhance and separate the back-scattered surface waves. The key idea is to calculate the virtual back-scattered surface waves by stacking the resulting virtual correlated and convolved traces associated with the incident and back-scattered waves. Stacking the virtual back-scattered surface waves improves their signal-to-noise ratio and separates the back-scattered surface-waves from the incident field. Both synthetic and field data results validate the robustness of this method.

Radiation exposure to workers at cyclotron facilities

International Nuclear Information System (INIS)

Ribeiro, M.S.; Sanches, M.P.; Sanchez, A.S.; Rodrigues, D.L.

2001-01-01

Radiopharmaceuticals quickly furnish the information doctors need to establish a precise diagnosis of the patient's condition, and therefore to prescribe the most effective therapy. In cancerology, F18-FDG, the most widely used PET imaging tracer, excels in the early detection of cancer tumors, even very tiny ones, which it locates and clearly distinguishes from healthy surrounding tissues. IPEN-CNEN/SP has two cyclotron accelerators used mainly for radioisotope production to be utilized in nuclear medicine for diagnosis and therapy. The first is a CV-28 cyclotron, variable energy that came into operation in 1982, which was used to produce F18-FDG and Iodine 123 up to 1998. The second, a Cyclone 30 cyclotron, 30 MeV, commenced operation in 1998 for certification purpose, and due to increase demand for radiopharmaceuticals in Brazil, started F18-FDG production in 1999. Cyclotron Laboratory will be a reference Research and Developing Center in our country and will help the Brazilian and Latin-American community. It is necessary to have an adequate database to allow regular follow up and analysis of the individual dose distributions for each group involved in the cyclotron activities. These databases are also important means to assess the effectiveness of efforts in order to maintain doses ALARA and reduce inequalities. The official individual occupational dosimetry is provided by certified Laboratory of Thermoluminescent Dosimetry at IPEN-CNEN/SP. This paper describes the occupational doses distribution in Laboratory of Cyclotrons at IPEN-CNEN/SP from January, 1998 to July, 2000 and propose improvements for the future. (author)

Electron-cyclotron wave propagation, absorption and current drive in the presence of neoclassical tearing modes

Science.gov (United States)

Isliker, Heinz; Chatziantonaki, Ioanna; Tsironis, Christos; Vlahos, Loukas

2012-09-01

We analyze the propagation of electron-cyclotron waves, their absorption and current drive when neoclassical tearing modes (NTMs), in the form of magnetic islands, are present in a tokamak plasma. So far, the analysis of the wave propagation and power deposition in the presence of NTMs has been performed mainly in the frame of an axisymmetric magnetic field, ignoring any effects from the island topology. Our analysis starts from an axisymmetric magnetic equilibrium, which is perturbed such as to exhibit magnetic islands. In this geometry, we compute the wave evolution with a ray-tracing code, focusing on the effect of the island topology on the efficiency of the absorption and current drive. To increase the precision in the calculation of the power deposition, the standard analytical flux-surface labeling for the island region has been adjusted from the usual cylindrical to toroidal geometry. The propagation up to the O-point is found to be little affected by the island topology, whereas the power absorbed and the driven current are significantly enhanced, because the resonant particles are bound to the small volumes in between the flux surfaces of the island. The consequences of these effects on the NTM evolution are investigated in terms of the modified Rutherford equation.

Electron-cyclotron wave propagation, absorption and current drive in the presence of neoclassical tearing modes

International Nuclear Information System (INIS)

Isliker, Heinz; Chatziantonaki, Ioanna; Tsironis, Christos; Vlahos, Loukas

2012-01-01

We analyze the propagation of electron-cyclotron waves, their absorption and current drive when neoclassical tearing modes (NTMs), in the form of magnetic islands, are present in a tokamak plasma. So far, the analysis of the wave propagation and power deposition in the presence of NTMs has been performed mainly in the frame of an axisymmetric magnetic field, ignoring any effects from the island topology. Our analysis starts from an axisymmetric magnetic equilibrium, which is perturbed such as to exhibit magnetic islands. In this geometry, we compute the wave evolution with a ray-tracing code, focusing on the effect of the island topology on the efficiency of the absorption and current drive. To increase the precision in the calculation of the power deposition, the standard analytical flux-surface labeling for the island region has been adjusted from the usual cylindrical to toroidal geometry. The propagation up to the O-point is found to be little affected by the island topology, whereas the power absorbed and the driven current are significantly enhanced, because the resonant particles are bound to the small volumes in between the flux surfaces of the island. The consequences of these effects on the NTM evolution are investigated in terms of the modified Rutherford equation. (paper)

Neutron field inside a PET Cyclotron vault room

International Nuclear Information System (INIS)

Vega C, H.R.; Mendez, R.; Iniguez, M.P.; Climent, J.M.; Penuelas, I.; Barquero, R.

2006-01-01

The neutron field around a Positron Emission Tomography cyclotron was investigated during 18 F radioisotope production with an 18 MeV proton beam. In this study the Ion Beam Application cyclotron, model Cyclone 18/9, was utilized. Measurements were carried out with a Bonner sphere neutron spectrometer with pairs of thermoluminescent dosemeters (TLD600 and TLD700) as thermal neutron detector. The TLDs readouts were utilized to unfold the neutron spectra at three different positions inside the cyclotron's vault room. With the spectra the Ambient dose equivalent was calculated. Neutron spectra unfolding were performed with the BUNKIUT code and the UTA4 response matrix. Neutron spectra were also determined by Monte Carlo calculations using a detailed model of cyclotron and vault room. (Author)

Ramifide resonators for cyclotrons

International Nuclear Information System (INIS)

Smirnov, Yu.V.

2000-01-01

The resonators with the conductors ramified form for cyclotrons are systematized and separated into the self-contained class - the ramified resonators for cyclotrons (Carr). The ramified resonators are compared with the quarter-wave and half-wave nonramified resonators, accomplished from the transmitting lines fragments. The CRR are classified into two types: ones with the additional structural element, switched in parallel and in series. The CRR may include several additional structural elements. The CRR calculations may be concluded by analytical methods - the method of matrix calculation or the method of telegraph equations and numerical methods - by means of the ISFEL3D, MAFIA and other programs [ru

Status Report on Cyclotron Operation

International Nuclear Information System (INIS)

Kovacs, P.; Szuecs, I.; Ander, I.; Lakatos, T.; Tarkanyi, F.

2004-01-01

Complete text of publication follows. The operation of the cyclotron in 2004 was concentrated to the usual 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 3554 hours, the time used for systematic maintenance was 450 hours. The breakdown periods amounted to 70 hours last year, included in it a 50 hours repair of RF control module under guarantee. The cyclotron was available for users during 3034 hours. The effectively used beam-on-target time statistics is summarized in Table 1. Developments: A new measuring site with a HPGe detector based gamma spectrometer is under installation in the basement of the Cyclotron Laboratory. A two channel pneumatic rabbit system is also under development to enable fast transport of samples between the new measuring site and two irradiation sites (the low intensity fast neutron irradiation site and the beam line used for Thin Layer Activation). (author)

Cyclotron-based neutron source for BNCT

Energy Technology Data Exchange (ETDEWEB)

Mitsumoto, T.; Yajima, S.; Tsutsui, H.; Ogasawara, T.; Fujita, K. [Sumitomo Heavy Industries, Ltd (Japan); Tanaka, H.; Sakurai, Y.; Maruhashi, A. [Kyoto University Research Reactor Institute (Japan)

2013-04-19

Kyoto University Research Reactor Institute (KURRI) and Sumitomo Heavy Industries, Ltd. (SHI) have developed a cyclotron-based neutron source for Boron Neutron Capture Therapy (BNCT). It was installed at KURRI in Osaka prefecture. The neutron source consists of a proton cyclotron named HM-30, a beam transport system and an irradiation and treatment system. In the cyclotron, H- ions are accelerated and extracted as 30 MeV proton beams of 1 mA. The proton beams is transported to the neutron production target made by a beryllium plate. Emitted neutrons are moderated by lead, iron, aluminum and calcium fluoride. The aperture diameter of neutron collimator is in the range from 100 mm to 250 mm. The peak neutron flux in the water phantom is 1.8 Multiplication-Sign 109 neutrons/cm{sup 2}/sec at 20 mm from the surface at 1 mA proton beam. The neutron source have been stably operated for 3 years with 30 kW proton beam. Various pre-clinical tests including animal tests have been done by using the cyclotron-based neutron source with {sup 10}B-p-Borono-phenylalanine. Clinical trials of malignant brain tumors will be started in this year.

Radioisotope production with a medical cyclotron

International Nuclear Information System (INIS)

Silvester, D.J.

1974-01-01

The cyclotron of Hammersmith hospital in England was completed and started the operation in 1955. The feature is in its design operable at high beam current, reaching 500μA in internal beam and 300μA in external beam. In 1960's, twelve nuclides of radioactive pharmaceuticals were produced with the cyclotron. C-11, N-13 and O-15 have been used in the form of radioactive gases such as CO or H 2 O to test lung functions. F-18 has been used for bone scanning. K-43 is employed in the research of electrolyte balancing together with Na-24 and Br-77. Fe-52 is utilized in iron ion researches as a tracer. Cs-129 is highly evaluated as an isotope for imaging cardiac clogging part. Radioisotopes must be much more used in the examination of in vivo metabolic function. For this purpose, peculiarly labelled compounds should be further developed. It is welcome that the persons paying attention to the medical prospect of cyclotrons are increasing. The author hopes to continue his endeavour to find new products made with the cyclotron for human welfare. (Wakatsuki, Y.)

Space plasma physics at the Rutherford Appleton Laboratory

International Nuclear Information System (INIS)

Bryant, D.A.; Bingham, R.; Edwards, T.; Hall, D.S.; Ward, A.K.

1984-03-01

The Rutherford Appleton Laboratory (RAL) is contributing instruments and a spacecraft to several imminent and excitingly new explorations of the plasma phenomena arising from the interaction between the solar wind and the Earth, and the solar wind and a comet. The projects in which the Laboratory is engaged, in collaboration with university and other research groups in the UK and abroad, include the AMPTE mission, which will trace the flow of particles injected into the solar wind, the GIOTTO encounter with comet Halley, the VIKING exploration of the generation of the aurora, and the CRRES and ISTP missions to clarify the structure and dynamics of the Earth's magnetosphere. These projects are outlined, together with the results of recent studies of particle acceleration and pulsations in the aurora. (author)

NORTICA - a new code for cyclotron analysis

International Nuclear Information System (INIS)

Gorelov, D.; Johnson, D.; Marti, F.

2001-01-01

The new package NORTICA (Numerical ORbit Tracking In Cyclotrons with Analysis) of computer codes for beam dynamics simulations is under development at NSCL. The package was started as a replacement for the code MONSTER developed in the laboratory in the past. The new codes are capable of beam dynamics simulations in both CCF (Coupled Cyclotron Facility) accelerators, the K500 and K1200 superconducting cyclotrons. The general purpose of this package is assisting in setting and tuning the cyclotrons taking into account the main field and extraction channel imperfections. The computer platform for the package is Alpha Station with UNIX operating system and X-Windows graphic interface. A multiple programming language approach was used in order to combine the reliability of the numerical algorithms developed over the long period of time in the laboratory and the friendliness of modern style user interface. This paper describes the capability and features of the codes in the present state

NORTICA—a new code for cyclotron analysis

Science.gov (United States)

Gorelov, D.; Johnson, D.; Marti, F.

2001-12-01

The new package NORTICA (Numerical ORbit Tracking In Cyclotrons with Analysis) of computer codes for beam dynamics simulations is under development at NSCL. The package was started as a replacement for the code MONSTER [1] developed in the laboratory in the past. The new codes are capable of beam dynamics simulations in both CCF (Coupled Cyclotron Facility) accelerators, the K500 and K1200 superconducting cyclotrons. The general purpose of this package is assisting in setting and tuning the cyclotrons taking into account the main field and extraction channel imperfections. The computer platform for the package is Alpha Station with UNIX operating system and X-Windows graphic interface. A multiple programming language approach was used in order to combine the reliability of the numerical algorithms developed over the long period of time in the laboratory and the friendliness of modern style user interface. This paper describes the capability and features of the codes in the present state.

Survey on radionuclide producing using cyclotron method in Malaysia

International Nuclear Information System (INIS)

Mohd Fadli Mohammad Noh

2008-01-01

This research discuss about basic design and systems of medical cyclotron that Malaysia currently have, its applications in radionuclide production and upcoming technologies of cyclotron. Surveys have been carried out on cyclotron facilities at Hospital Putrajaya and Wijaya International Medical Center, WIMC as well as reactor facility at Malaysia Nuclear Agency. The sources in this research also involves on-line and library searches. Information obtained are recorded, categorized, synthesized and discussed. systems of cyclotron of Hospital Putrajaya are further discussed in details. Based from the surveys carried out, it is found out that cyclotron facilities both in Hospital Putrajaya and WIMC only produce ( 18 F)FDG with radioactivity of 18 F produced in 2007 are 16479 mCi and 92546 mCi respectively. Survey also revealed that radioisotope production at Nuclear Malaysia has had its operation been ceased. A new radiopharmaceutical, namely CHOL is suggested to be synthesized by both facilities as a new PET tracer. Latest developments concerning technologies of cyclotron as well as other accelerators such as laser for future medical accelerator, prospect of boron neutron capture and the potential of hadron therapy in Malaysia are discussed here. Radioisotope production in Malaysia is expected to keep booming in future due to increase in usage of PET techniques and the construction of more compact, easy to handle and less costly cyclotrons. (author)

Experimental verification of Rutherford's transversal section of energies between 200 and 700 Kev

International Nuclear Information System (INIS)

Lara E, J.A.

1976-01-01

The objective was to try to verify the validity of Rutherford's transversal section, for the interval of energies between 200 and 700 Kev. It was decided to carry out this work in order to underline the fact that a great part of experiments such as: a) the use of thin films to make mirrors or produce condensers, b) the study of the composition of dielectric layers and the formation of metallic contacts with semiconductors, c) the mapping of the mass distribution at depths varying between hundreds and thousands of angstroms, d) the detection of low mass impurities on the crystal surface, e) the implantation of ions are based on the validity of Rutherford's dispersion theory, while this doesn't succeed with high energies due to the appearance of nuclear resonances, or with low energies due to the appearance of atomic effects which distort the results. The results show a standard error of approxiamately 7% with respect to the average. In conclusion, some limitations are noted in relation to the nuclei and the interval of energy; these limitations should be taken into consideration and recommendations are made about how to obtain more reliable results. (author)

Considerations, measurements and logistics associated with low-energy cyclotron decommissioning

International Nuclear Information System (INIS)

Sunderland, J. J.; Erdahl, C. E.; Bender, B. R.; Sensoy, L.; Watkins, G. L.

2012-01-01

The University of Iowa’s 20-year-old 17 MeV Scanditronix cyclotron underwent decommissioning in the summer of 2011. To satisfy local, state and federal regulations defining removal, transportation and long-term safe and environmentally secure disposal of the 22 ton activated cyclotron, a series of nuclear spectroscopic measurements were performed to characterize the nature and extent of proton and neutron activation of the 22-ton cyclotron, its associated targets, and the concrete wall that was demolished to remove the old cyclotron. Neutron activation of the concrete wall was minimal and below exempt concentrations resulting in standard landfill disposal. The cyclotron assessment revealed the expected array of short and medium-lived radionuclides. Subsequent calculations suggest that meaningful levels residual activity will have decayed virtually to background after 15 years, with the total residual activity of the entire cyclotron dropping below 37 MBq (1 mCi).

Composition of Renaissance paint layers: simultaneous particle induced X-ray emission and backscattering spectrometry.

Science.gov (United States)

de Viguerie, L; Beck, L; Salomon, J; Pichon, L; Walter, Ph

2009-10-01

Particle induced X-ray emission spectroscopy (PIXE) is now routinely used in the field of cultural heritage. Various setups have been developed to investigate the elemental composition of wood/canvas paintings or of cross-section samples. However, it is not possible to obtain information concerning the quantity of organic binder. Backscattering spectrometry (BS) can be a useful complementary method to overcome this limitation. In the case of paint layers, PIXE brings the elemental composition (major elements to traces) and the BS spectrum can give access to the proportion of pigment and binder. With the use of 3 MeV protons for PIXE and BS simultaneously, it was possible to perform quantitative analysis including C and O for which the non-Rutherford cross sections are intense. Furthermore, with the use of the same conditions for PIXE and BS, the experiment time and the potential damage by the ion beam were reduced. The results obtained with the external beam of the Accélérateur Grand Louvre pour l'Analyse Elementaire (AGLAE) facility on various test painting samples and on cross sections from Italian Renaissance masterpieces are shown. Simultaneous combination of PIXE and BS leads to a complete characterization of the paint layers: elemental composition and proportion of the organic binder have been determined and thus provide useful information about ancient oil painting recipes.

Development of baby cyclotron for PET in Korea

International Nuclear Information System (INIS)

Chai, J.S.; Kim, Y.S.; Hu, J.Y.; Shin, Y.C.; Yoon, M.H.

2001-01-01

Development of a 13 MeV cyclotron for Positron Emission Tomography (PET) has been in progress since April 1999 at the Korea Cancer Center Hospital (KCCH). The study has been carried out in a joint collaboration between KCCH and the Pohang University of Science and Technology (POSTECH). Increasing desire for an uninterrupted, reliable and timely supply of the isotopes to customers has prompted obtaining a dedicated 5-13 MeV cyclotron for PET applications and pursuing the purchase of another 30MeV medical cyclotron in the very near future. A decision has been made to design the PET cyclotron in Korea. This will not only ease the problems associated with maintenance during operation but also keep the door open for continuous upgrading of the machine in the future

An experimental study on cyclotron-Cherenkov radiation

Energy Technology Data Exchange (ETDEWEB)

Lee, C Y; Masuzaki, M; Yoshida, H; Toyosugi, N; Kamada, K; Ando, R [Kanazawa Univ. (Japan). Department of Physics

1997-12-31

Dielectric-loaded cylindrical waveguide configurations with an injected electron beam in which the growth rate of the cyclotron-Cherenkov instability surpasses that of the Cherenkov instability were sought by numerical treatment, and one configuration of this kind was found. This configuration consists of a metallic core and an outer metallic cylinder with a dielectric liner on the inner surface. Based on the calculations, an experimental device was designed and assembled to investigate experimentally radiation due to the cyclotron-Cherenkov instability. Beam propagation in the dielectric-loaded coaxial waveguide and microwave radiation due to the cyclotron-Cherenkov instability and the Cherenkov instability were studied. (author). 6 figs., 10 refs.

Cyclotron Development and Technical Aspects on Accelerator Based Laboratory Development

International Nuclear Information System (INIS)

Sunarhadijoso

2000-01-01

BATAN is planning to establish an accelerator-based laboratory at P3TM Yogyakarta as an effort in the development and use of accelerator technology for improving industrial performance and public welfare. This paper reviews several aspects of cyclotron technology and describes the combination of a linear accelerator - cyclotron system as an alternative to be considered in the planing of the laboratory. The progress of cyclotron technology is discussed covering three generations, i.e. conventional cyclotron, synchrocyclotron and AVF cyclotron generations. The planning should not consider the accelerator application for radioisotope production because it is established in Serpong with the existing negative ion cyclotron. The proposed facility at P3TM may comprise two linear accelerators coupled with a positive ion cyclotron of synchrocyclotron generation. In fact, the attachment of the synchrocyclotron unit is flexible and it can be installed subsequently if the higher energy particle beam, which can not be produced by the linear accelerators, is extremely needed. Some technical aspects related to ion beam application, building construction and infrastructure, human resources, and specification of function test are discussed for additional information in the implementation of the planning. (author)

Cyclotrons in developing countries

International Nuclear Information System (INIS)

Vera Ruiz, Hernan

2004-01-01

Cyclotron accelerators are prolific sources of charged particle for the production of radionuclides and have become an essential tool in the practice of modern nuclear medicine by providing reliable radiotracers for SPECT and PET studies. In a recent survey conducted by the IAEA in 2001, the growth in the number of cyclotron facilities installed in laboratories and hospitals in developed as well as developing countries was recorded. This trend, which started in the late 70's, continues in the present time also and all indications are that it will continue in the next five to ten years. The reasons for this growth are several: technology involved has become more user or 'hospital friendly', third party reimbursement for several clinical studies based on F-18 PET radiopharmaceuticals at least in some of the advanced countries started in 1998 and above all, the clear irrefutable and demonstrable conclusion of the positive cost/benefit outcomes of PET studies in the field of oncology to a lesser degree, thus far, for cardiology and neurology. It is however recognizable that the overall financial cost of the technology, which comprises the premises to house the facility, the cyclotron accelerator, the corresponding radiochemistry and quality control equipment and the PET cameras can be nevertheless an expensive proposition that requires careful advance planning. This fact is even more relevant when the facility is planned for installation in a developing country, which, frequently, in addition to having a lack of sufficient financial resources, do have shortage of qualified human resources to efficiently run the facility. In spite of the above, it is fact that more and more public as well as private organizations in the developing countries are setting up cyclotron/PET programmes or are seriously considering the installation of such a facility

Suppression of cyclotron instability in Electron Cyclotron Resonance ion sources by two-frequency heating

International Nuclear Information System (INIS)

Skalyga, V.; Izotov, I.; Mansfeld, D.; Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.; Tarvainen, O.

2015-01-01

Multiple frequency heating is one of the most effective techniques to improve the performance of Electron Cyclotron Resonance (ECR) ion sources. The method increases the beam current and average charge state of the extracted ions and enhances the temporal stability of the ion beams. It is demonstrated in this paper that the stabilizing effect of two-frequency heating is connected with the suppression of electron cyclotron instability. Experimental data show that the interaction between the secondary microwave radiation and the hot electron component of ECR ion source plasmas plays a crucial role in mitigation of the instabilities

Initial operation of the cyclotron CYTRACK

International Nuclear Information System (INIS)

Denisov, Yu.N.; Dolya, S.N.; Kalinichenko, V.V.; Karamysheva, G.A.; Kostromin, S.A.; Fedorenko, S.B.

2005-01-01

The industrial cyclotron CYTRACK is dedicated to produce the track membranes. It is the basic instrument for the industry of membrane products to be consumed in medicine, biotechnology, pharmacology, microelectronics and many other industries. Cyclotron CYTRACK started working in August 2002. Argon ions were accelerated to the project energy - 2.4 MeV/nucleon, the extracted beam intensity was about 200 nA, the extraction efficiency totaled ∼50%

Operational experience and recent developments at the National Medical Cyclotron, Sydney

International Nuclear Information System (INIS)

Conard, E.M.; Arnott, D.W.

1996-01-01

The National Medical Cyclotron, Sydney, Australia commenced operation in mid 1991, with a mission to provide PET and SPECT radionuclides throughout Australia. The realization of the present production capacity has been synonymous with the development of the facility's industrial cyclotron (IBA Cyclone 30). The choice of cyclotron was based on the Cyclone 30's virtues as a compact, user-friendly, energy efficient cyclotron, offering the beam quality characteristic of negative ion technology. Development of the cyclotron has improved reliability and increased beam capacity, while improvements to targetry have increased production reliability. More recently, the installation and commissioning of a new solid target irradiation facility has provided much needed redundancy. This paper describes the major cyclotron and targetry developments carried out to date. (orig.)

Manufacturing on the radiopharmaceuticals produced by cyclotron

International Nuclear Information System (INIS)

Ueda, Nobuo

1994-01-01

Radiopharmaceutical (RP) produced by cyclotrons are widely used for the in vivo diagnosis of various diseases such as cancer, cerebral vascular disorders and cardiac diseases. The nuclides used as RPs and their nuclear reactions, and the quantity of RPs supplied in Japan in the last five years are shown. These RPs are delivered to about 1,100 hospitals in Japan. Thallium-201 and iodine-123 showed very high growth rate. Recently, two new I-123 RPs, BMIPP and MIBG which are heart-imaging agents, have been supplied. It suggests that the quantity of I-123 will increase much more in future. The image diagnostic method using RPs is called in vivo nuclear medicine, and has become the indispensable means for medical institutions together with X-ray CT, nuclear magnetic resonance imaging and ultrasonic diagnosis. The RPs for in vivo diagnosis generally used at present are classified into those labeled with the RIs produced with cyclotrons and those labeled with Tc-99m formed by the decay of Mo-99. The quantity being used is overwhelmingly more in the latter, but the former shows the tendency of growth. The commercial production of cyclotron RIs for medical use, the chemical forms and the diagnostic purposes of the RPs using cyclotron RIs, and the state of use of the cyclotron-produced RPs are reported. (K.I.)

Disruption avoidance by means of electron cyclotron waves

International Nuclear Information System (INIS)

Esposito, B; Granucci, G; Nowak, S; Lazzaro, E; Maraschek, M; Giannone, L; Gude, A; Igochine, V; McDermott, R; Poli, E; Reich, M; Sommer, F; Stober, J; Suttrop, W; Treutterer, W; Zohm, H

2011-01-01

Disruptions are very challenging to ITER operation as they may cause damage to plasma facing components due to direct plasma heating, forces on structural components due to halo and eddy currents and the production of runaway electrons. Electron cyclotron (EC) waves have been demonstrated as a tool for disruption avoidance by a large set of recent experiments performed in ASDEX Upgrade and FTU using various disruption types, plasma operating scenarios and power deposition locations. The technique is based on the stabilization of magnetohydrodynamic (MHD) modes (mainly m/n = 2/1) through the localized injection of EC power on the resonant surface. This paper presents new results obtained in ASDEX Upgrade regarding stable operation above the Greenwald density achieved after avoidance of density limit disruptions by means of ECRH and suitable density feedback control (L-mode ohmic plasmas, I p = 0.6 MA, B t = 2.5 T) and NTM-driven disruptions at high-β limit delayed/avoided by means of both co-current drive (co-ECCD) and pure heating (ECRH) with power ≤1.7 MW (H-mode NBI-heated plasmas, P NBI ∼ 7.5 MW, I p = 1 MA, B t = 2.1 T, q 95 ∼ 3.6). The localized perpendicular injection of ECRH/ECCD onto a resonant surface leads to the delay and/or complete avoidance of disruptions. The experiments indicate the existence of a power threshold for mode stabilization to occur. An analysis of the MHD mode evolution using the generalized Rutherford equation coupled to the frequency and phase evolution equations shows that control of the modes is due to EC heating close to the resonant surface. The ECRH contribution (Δ' H term) is larger than the co-ECCD one in the initial and more important phase when the discharge is 'saved'. Future research and developments of the disruption avoidance technique are also discussed.

Disorder in silicon films grown epitaxially at low temperature

International Nuclear Information System (INIS)

Schwarzkopf, J.; Selle, B.; Bohne, W.; Roehrich, J.; Sieber, I.; Fuhs, W.

2003-01-01

Homoepitaxial Si films were prepared by electron cyclotron resonance plasma enhanced chemical vapor deposition on Si(100) substrates at temperatures of 325-500 deg. C using H 2 , Ar, and SiH 4 as process gases. The gas composition, substrate temperature, and substrate bias voltage were systematically varied to study the breakdown of epitaxial growth. Information from ion beam techniques, like Rutherford backscattering and heavy-ion elastic recoil detection analysis, was combined with transmission and scanning electron micrographs to examine the transition from ordered to amorphous growth. The results suggest that the breakdown proceeds in two stages: (i) highly defective but still ordered growth with a defect density increasing with increasing film thickness and (ii) formation of conically shaped amorphous precipitates. The hydrogen content is found to be directly related to the degree of disorder which acts as sink for excessive hydrogen. Only in almost perfect epitaxially grown films is the hydrogen level low, and an exponential tail of the H concentration into the crystalline substrate is observed as a result of the diffusive transport of hydrogen

The nuclear interaction analysis methods for diagnostics of high power ion beam technologies

Energy Technology Data Exchange (ETDEWEB)

Ryzhkov, V A; Grushin, I I; Remnev, G E [Nuclear Physics Inst., Tomsk (Russian Federation)

1997-12-31

The complex of Nuclear Interaction Analysis Methods including charged particle activation analysis (CPAA and HIAA), spectrometry of ion induced gamma-emission (PIGE and HIIGE) , characteristic X-ray emission (PIXE), and Rutherford Backscattering Spectrometry (RBS), have been used for diagnostics of the High Power Ion Beam (HPIB) assisted technologies. Accelerated ion beams from the EG-2.5 electrostatic generator and U-120 cyclotron were used for implementation of the techniques. The complex allows a lot of problems of elemental and isotopic analysis to be addressed. First, it is the determination of micro- and macrocomponents of modified materials; second, determination of surface density of thin films, multilayers and coatings, total surface gaseous contamination and amounts of the elements implanted in specimens; third, measurement of concentration depth profiles of the elements. Experiments have shown that the preferable application of nuclear analysis methods allows us to avoid the considerable errors arising when the concentration depth profiles of elements are measured by SIMS or AES in studies of mass transfer processes induced by HPIBs. (author). 1 tab., 2 figs., 3 refs.

Electron cyclotron emission measurements during 28 GHz electron cyclotron resonance heating in Wendelstein WVII-A stellarator

International Nuclear Information System (INIS)

Hartfuss, H.J.; Gasparino, U.; Tutter, M.; Brakel, R.; Cattanei, G.; Dorst, D.; Elsner, A.; Engelhardt, K.; Erckmann, V.; Grieger, G.; Grigull, P.; Hacker, H.; Jaeckel, H.; Jaenicke, R.; Junker, J.; Kick, M.; Kroiss, H.; Kuehner, G.; Maassberg, H.; Mahn, C.; Mueller, G.; Ohlendorf, W.; Rau, F.; Renner, H.; Ringler, H.; Sardei, F.; Weller, A.; Wobig, H.; Wuersching, E.; Zippe, M.; Kasparek, W.; Mueller, G.A.; Raeuchle, E.; Schueller, P.G.; Schwoerer, K.; Thumm, M.

1987-11-01

Electron cyclotron emission measurements have been carried out on electron cyclotron resonance heated plasmas in the WENDELSTEIN VII-A Stellarator. Blackbody radiation from the thermalized plasma main body as well as radiation from a small amount of weakly relativistic suprathermal electrons has been detected. In addition sideband emission has been observed near the second harmonic of the heating line source. Harmonic generation and parametric wave decay at the upper hybrid layer may be a reasonable explanation. (orig.)

[Cyclotron based nuclear science

International Nuclear Information System (INIS)

1989-06-01

This report contains papers on the following topics: Heavy ion reactors, nuclear structure and fundamental interactions; atomic and materials studies; nuclear theory; and superconducting cyclotron and instrumentation

A new generation of medical cyclotrons for the 90's

International Nuclear Information System (INIS)

Milton, B.F.

1995-08-01

Cyclotrons continue to be efficient accelerators for use in radio-isotope production. In recent years, developments in accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper the authors will survey recent developments in the areas of cyclotron technology as they relate to the new generation of commercial cyclotrons. Existing and potential markets for these cyclotrons will be presented. They will also discuss the possibility of systems capable of extracted energies up to 150 MeV and extracted beam currents of up to 2.0 mA

A new generation of medical cyclotrons for the 90's

International Nuclear Information System (INIS)

Milton, B.F.

1995-08-01

Cyclotrons continue to be efficient accelerators for use in radio-isotope production. In recent years, developments in accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology as they relate to the new generation of commercial cyclotrons. Existing and potential markets for these cyclotrons will be presented. We will also discuss the possibility of systems capable of extracted energies up to 150 MeV and extracted beam currents of up to 2.0 mA. (author)

Evidence of a tropospheric aerosol backscatter background mode

Science.gov (United States)

Rothermel, Jeffry; Bowdle, David A.; Vaughan, J. Michael; Post, Madison J.

1989-01-01

Vertical profiles of atmospheric aerosol backscatter coefficients at 10.6 microns obtained with airborne and ground-based lidar are compared. Both sets of profiles show a high frequency of occurrence of low backscatter over a limited range of values in the middle and upper troposphere. It is suggested that this narrow range indicates a ubiquitous background mode for atmospheric backscatter around the globe. Implications of such a mode for global scale aerosol models and for the design of satellite-borne lidar-based sensors are discussed.

A small low energy cyclotron for radioisotope measurements

International Nuclear Information System (INIS)

Bertsche, K.J.

1989-11-01

Direct detection of 14 C by accelerator mass spectrometry has proved to be a much more sensitive method for radiocarbon dating than the decay counting method invented earlier by Libby. A small cyclotron (the ''cyclotrino'') was proposed for direct detection of radiocarbon in 1980. This combined the suppression of background through the use of negative ions, which had been used effectively in tandem accelerators, with the high intrinsic mass resolution of a cyclotron. Development of a small electrostatically-focused cyclotron for use as a mass spectrometer was previously reported but the sensitivity needed for detection of 14 C at natural abundance was not achieved. The major contributions of this work are the integration of a high current external ion source with a small flat-field, electrostatically-focused cyclotron to comprise a system capable of measuring 14 C at natural levels, and the analysis of ion motion in such a cyclotron, including a detailed analysis of phase bunching and its effect on mass resolution. A high current cesium sputter negative ion source generates a beam of carbon ions which is pre-separated with a Wien filter and is transported to the cyclotron via a series of electrostatic lenses. Beam is injected radially into the cyclotron using electrostatic deflectors and an electrostatic mirror. Axial focusing is entirely electrostatic. A microchannel plate detector is used with a phase-grated output. In its present form the system is capable of improving the sensitivity of detecting 14 C in some biomedical experiments by a factor of 10 4 . Modifications are discussed which could bring about an additional factor of 100 in sensitivity, which is important for archaeological and geological applications. Possibilities for measurements of other isotopes, such as 3 H, and 10 Be, and 26 Al, are discussed. 70 refs

Preliminary backscatter results from the hydrosweep multibeam system

Digital Repository Service at National Institute of Oceanography (India)

Hagen, R.A.; Chakraborty, B.; Schenke, H.W.

of Oceanography to convert the measured electrical energy into acoustic backscatter energy. This conversion includes corrections for the position, slope, and area of the scattering surface. In this paper we present backscatter data from several areas surveyed...

U-2g0 cyclotron operational experience and improvement

International Nuclear Information System (INIS)

Gigal, B.N.; Gul'bekyan, G.G.; Kozlov, S.I.; Oganesyan, R.Ts.

1983-01-01

Brief description of main syste's of the U-200 isochronous 2-m cyclotron put into opera ion in 1968 is given and its operational characteristics a e presented. The cyclotron is used for conducting inve tigations in the field of nuclear physics. Ions from d uterium to argon have been accelerated in the cyclotro'. Annual time of target irradiation constitutes 2000-4000. The specific features of the cyclotron are: high l vel of a magnetic field (of about 20 kOe), possibili y of acceleration of ions with different mass-to-charge ratio a low correcting winding power, simple and high-e fective beam extraction by the method of charge exchange on a thin target allowing to vary smoothly energy of extracted ons. An experience in the U-200 cyclotron development and o eration is used as the basis for designing and choosing basic parameters of the U-200P, U-250, U-400 heavy ion cyclotrons

Electron-Cyclotron Waves

NARCIS (Netherlands)

Westerhof, E.

1994-01-01

The essential elements of the theory of electron cyclotron waves are reviewed, The two main electro-magnetic modes of propagation are identified and their dispersion and absorption properties are discussed. The importance of the use of the relativistic resonance condition is stressed.

Rutherford X-ray spectrometer readout

International Nuclear Information System (INIS)

Bateman, J.E.

1978-07-01

Rutherford electronic X-ray spectrometer readout is based on the combination of two established techniques (a) the detection and location of soft X-rays by means of multichannel electron multiplier arrays (MCP's), and (b) the electronic readout of charge distributions (generally in multi-wire proportional counters) by means of the delay line techniques. In order for the latter device to function well a charge signal of approximately 10 6 electrons must be available to the delay line wand. This is achieved in the present device by means of two cascaded MCP's which can produce electron gains up to approximately 10 8 , and so operate the delay line from the single electron pulses generated at the front face of an MCP by a soft X-ray. The delay line readout technique was chosen because of its simplicity (both in terms of the necessary hardware and the associated electronics), robustness, and ease of implementation. In order to achieve the target spatial resolution of 50 μm (fwhm) or 20 μm (standard deviation) it was necessary to adapt the charge collection system so that the readout takes place from a length of delay line 200 mm long. The general layout of the system and the functions of the electronic circuits are described. Performance testing, setting up procedures and trouble shooting of the system are discussed. (U.K.)

Development of HM12 cyclotron for PET

International Nuclear Information System (INIS)

Morita, Takuzo; Kawama, Tetsuo; Fujii, Kazuo

2000-01-01

In Japan, there are at present more than 30 PET (Positron Emission Tomography) facilities. The movements of medical insurance application to the PET diagnosis using [ 18 F] FDG (2-[ 18 F]-fluoro-2-deoxy-glucose) by the Ministry of Health and Welfare are being enhanced by PET related people. Therefore, more clinical centers using PET system are expected to be built in the near future. HM12 cyclotron was developed to meet such market demands for PET, and the prototype machine has been rent to Cyclotron Radio Isotope Center (CYRIC) of Tohoku University since Oct. 1998 for their use of clinical research with positron emitters like 11 C, 13 N, 15 O and 18 F. We got many technical data of HM12 Cyclotron on the clinical base. The data was enough to establish the reliability of HM12 system operation under the clinical condition. The first commercial product of HM12 Cyclotron was delivered to National Cancer Center in March 2000. The final performance test will be finished by the end of June 2000. (author)

Manganese in silicon carbide

Energy Technology Data Exchange (ETDEWEB)

Linnarsson, M.K., E-mail: marga@kth.se [Royal Institute of Technology, School of Information and Communication Technology, P.O. Box E229, SE-16440 Kista-Stockhom (Sweden); Hallen, A. [Royal Institute of Technology, School of Information and Communication Technology, P.O. Box E229, SE-16440 Kista-Stockhom (Sweden)

2012-02-15

Structural disorder and relocation of implanted Mn in semi-insulating 4H-SiC has been studied. Subsequent heat treatment of Mn implanted samples has been performed in the temperature range 1400-2000 Degree-Sign C. The depth distribution of manganese is recorded by secondary ion mass spectrometry. Rutherford backscattering spectrometry has been employed for characterization of crystal disorder. Ocular inspection of color changes of heat-treated samples indicates that a large portion of the damage has been annealed. However, Rutherford backscattering shows that after heat treatment, most disorder from the implantation remains. Less disorder is observed in the [0 0 0 1] channel direction compared to [112{sup Macron }3] channel direction. A substantial rearrangement of manganese is observed in the implanted region. No pronounced manganese diffusion deeper into the sample is recorded.

Manganese in silicon carbide

International Nuclear Information System (INIS)

Linnarsson, M.K.; Hallén, A.

2012-01-01

Structural disorder and relocation of implanted Mn in semi-insulating 4H–SiC has been studied. Subsequent heat treatment of Mn implanted samples has been performed in the temperature range 1400–2000 °C. The depth distribution of manganese is recorded by secondary ion mass spectrometry. Rutherford backscattering spectrometry has been employed for characterization of crystal disorder. Ocular inspection of color changes of heat-treated samples indicates that a large portion of the damage has been annealed. However, Rutherford backscattering shows that after heat treatment, most disorder from the implantation remains. Less disorder is observed in the [0 0 0 1] channel direction compared to [112 ¯ 3] channel direction. A substantial rearrangement of manganese is observed in the implanted region. No pronounced manganese diffusion deeper into the sample is recorded.

Lower-hybrid absorption at the ion cyclotron harmonics

International Nuclear Information System (INIS)

Puri, S.

1975-01-01

In the presence of magnetic field gradients, the lower-hybrid wave can be absorbed through linear collisionless damping at the location of cyclotron or cyclotron harmonic resonances acting as singular turning points in the path of the advancing wave-front. (Auth.)

Stability and nonlinear dynamics of gyrotrons at cyclotron harmonics

International Nuclear Information System (INIS)

Saraph, G.P.; Nusinovich, G.S.; Antonsen, T.M. Jr.; Levush, B.

1992-01-01

Gyrotrons operating at higher harmonics of the cyclotron frequency can overcome the frequency limitations caused by achievable strength of the magnetic field. However, the excitation of modes at the fundamental frequency exhibit a major problem for stable operation of harmonic gyrotron at high power with high efficiency. Therefore the issues of stability of gyrotron operation at the cyclotron harmonics and nonlinear dynamics of mode interaction are of great importance. The results of the authors stability analysis and multimode simulation are presented here. A detailed nonlinear theory of steady state single mode operation at cyclotron harmonics has been presented previously, taking into account beam-wave coupling and nonlinear gain function at cyclotron harmonics. A set of equations describing low gain regime interaction of modes resonant at different cyclotron harmonics was studied before. The multifrequency time-dependent nonlinear analysis presented here is based on previous gyrotron studies and beam-wave interaction at cyclotron harmonics. The authors have determined the parameter space for stable single mode operation at the second harmonic. The nonlinear dynamics of mode evolution and mode interaction for a harmonic gyrotron is presented. A new nonlinear effect in which the parasite at the fundamental harmonic helps excite the operating mode at the second harmonic has been demonstrated

A mobile superconducting cyclotron for PET and neutron radiography

International Nuclear Information System (INIS)

Griffiths, R.

1988-01-01

The report addresses the development of a mobile superconducting cyclotron for PET (positron emission tomography) and neutron radiography. Proposals for an ultralight cyclotron were made by Finlan et al., who suggested a novel technique of utilising a superconducting magnet with RF acceleration and iron sectors contained within the room temperature bore of the magnet. Detailed design of a cyclotron based on this concept has progressed well at Oxford Instruments. The main design priorities were to minimise the weight and power consumption of the cyclotron. The cyclotron required a large amount of shielding to reduce either radiation background levels or stray magnetic field. Thus low background levels of radiation and magnetic field are key design criteria. The superconducting magnet has a mean field of 2.35 Tesla and a room temperature bore diameter of 500 mm. Three pairs of profiled iron sectors placed in the center of the warm bore of the magnet provide an azimuthally varying magnetic field. This permits the use of high beam currents with low background. A novel technique is incorporated to reduce the stray magnetic field and radiation from the cyclotron. The RF system consists of three pairs of resonators mounted within the warm bore of the magnet between the iron sectors. (Nogami, K.)

Conversion and improvement of the Rutherford Laboratory's magnetostatic computer code GFUN3D to the NMFECC CDC 7600

International Nuclear Information System (INIS)

Tucker, T.C.

1980-06-01

The implementation of a version of the Rutherford Laboratory's magnetostatic computer code GFUN3D on the CDC 7600 at the National Magnetic Fusion Energy Computer Center is reported. A new iteration technique that greatly increases the probability of convergence and reduces computation time by about 30% for calculations with nonlinear, ferromagnetic materials is included. The use of GFUN3D on the NMFE network is discussed, and suggestions for future work are presented. Appendix A consists of revisions to the GFUN3D User Guide (published by Rutherford Laboratory( that are necessary to use this version. Appendix B contains input and output for some sample calculations. Appendix C is a detailed discussion of the old and new iteration techniques

Strand critical current degradation in $Nb_{3}$ Sn Rutherford cables

CERN Document Server

Barzi, E; Higley, H C; Scanlan, R M; Yamada, R; Zlobin, A V

2001-01-01

Fermilab is developing 11 Tesla superconducting accelerator magnets based on Nb/sub 3/Sn superconductor. Multifilamentary Nb/sub 3/Sn strands produced using the modified jelly roll, internal tin, and powder-in-tube technologies were used for the development and test of the prototype cable. To optimize the cable geometry with respect to the critical current, short samples of Rutherford cable with packing factors in the 85 to 95% range were fabricated and studied. In this paper, the results of measurements of critical current, n-value and RRR made on the round virgin strands and on the strands extracted from the cable samples are presented. (5 refs).

K-, L- and M-shell X-ray productions induced by oxygen ions in the 0.8–1.6 MeV/amu range

Energy Technology Data Exchange (ETDEWEB)

Gorlachev, I., E-mail: Igor.Gorlachev@gmail.com [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Gluchshenko, N. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Ivanov, I. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); L.N. Gumilyov Eurasian National University, Mirzoyan 2, Astana (Kazakhstan); Kireyev, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Kozin, S.; Kurakhmedov, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); L.N. Gumilyov Eurasian National University, Mirzoyan 2, Astana (Kazakhstan); Platov, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Zdorovets, M. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Ural Federal University, Yekaterinburg 620002 (Russian Federation)

2016-08-15

The X-ray production cross sections induced by oxygen ions with projectile energies from 12.8 to 25.6 MeV for the elements from Al to Bi were measured. The applied approach is based on calculation of X-ray production cross sections through the cross section of Rutherford backscattering, which can be calculated with high accuracy using the Rutherford formula. The experimental results are compared to the predictions of ECPSSR and PWBA theories calculated with the ISICS code.

Transport equation theory of electron backscattering and x-ray production

International Nuclear Information System (INIS)

Fathers, D.J.; Rez, P.

1978-02-01

A transport equation theory of electron backscattering and x ray production is derived and applied to energy dissipation of 30-KeV electrons for copper as a function of depth and to the energy distribution of backscattered electrons for copper, aluminum, and gold. These results are plotted and compared with experiment. Plots for variations of backscattering with atomic number and with angle of incidence, and polar plots of backscattering for 30-keV electrons at normal incidence are also presented. 10 references, seven figures

Fabrication of beam diagnostic components for Superconducting Cyclotron at Kolkata

International Nuclear Information System (INIS)

Roy, S.; Bhattacharya, S.; Das, T.; Bhattacharyya, T.K.; Pal, S.; Pal, G.; Mallik, C.; Bhandari, R.K.

2009-01-01

The viewer probe and main probe are used for determining the position and current of charged particles as it is accelerated inside the superconducting cyclotron. The viewer probe is used to visually observe the shape of the charged particle beam inside the cyclotron with the help of a borescope. The main probe measures the distribution of charged particles. The viewer probe and main probe are bellow sealed. They can be positioned with an accuracy of 0.5 mm at different radii within the superconducting cyclotron. M9 slit is placed after the exit flange of the cyclotron. It determines the position of the beam leaving the cyclotron. The beam line has slits, faraday cup, beam viewers, collimators, etc. for beam diagnostics. This paper presents the mechanical design and details of beam diagnostic components. (author)

Interface behaviour and electrical performance of ruthenium ...

Indian Academy of Sciences (India)

Rutherford backscattering spectrometry; Raman spectroscopy; oxidation; silicide; Schottky barrier diodes; ruthenium ... water and then dried with nitrogen gas before being loaded into the vacuum ... laser of wavelength 514.6 nm. Full I–V and ...

Neutron radiography by using JSW baby cyclotron

International Nuclear Information System (INIS)

Toda, Yojiro

1995-01-01

At present, JSW baby cyclotrons are mostly used for the production of the radioisotopes for medical use. The attempt to use this baby cyclotron for neutron radiography began already in 1981. The feasibility of the neutron radiography for the explosives in metallic cases which are used for H1 rockets was investigated. In 1983, it was shown that the neutron radiography by using the baby cyclotron in Muroran Works, Japan Steel Works, Ltd. was able to be carried out as a routine work. Since then, the nondestructive inspection by neutron radiography has been performed for rocket pyrotechnic articles, and contributed to heighten their reliability. Further, the radiography by using fast neutrons was developed and put to practical use for recent large H2 rockets. The JSW baby cyclotron BC 168 which has been used for neutron radiography can accelerate 16 MeV protons or 8 MeV deuterons up to 50 μA. The principle of thermal neutron radiography is the generation of fast neutrons by irradiating a Be target with the proton beam accelerated by a baby cyclotron, the moderation of the fast neutrons, the formation of the thermal neutron flux of uniform distribution with a collimator, the thermal neutron flux hitting the Gd plate in a film cassette through an object, and the exposure of an X-ray film to electrons from the Gd plate. Fast neutron radiography apparatus, and commercial neutron radiography are described. (K.I.)

Strong Localization in Disordered Media: Analysis of the Backscattering Cone

KAUST Repository

Delgado, Edgar

2012-06-01

A very interesting effect in light propagation through a disordered system is Anderson localization of light, this phenomenon emerges as the result of multiple scattering of waves by electric inhomogeneities like spatial variations of index of refraction; as the amount of scattering is increased, light propagation is converted from quasi-diffusive to exponentially localized, with photons confined in a limited spatial region characterized by a fundamental quantity known as localization length. Light localization is strongly related to another interference phenomenon emerged from the multiple scattering effect: the coherent backscattering effect. In multiple scattering of waves, in fact, coherence is preserved in the backscattering direction and produces a reinforcement of the field flux originating an observable peak in the backscattered intensity, known as backscattering cone. The study of this peak provide quantitative information about the transport properties of light in the material. In this thesis we report a complete FDTD ab-initio study of light localization and coherent backscattering. In particular, we consider a supercontinuum pulse impinging on a sample composed of randomly positioned scatterers. We study coherent backscattering by averaging over several realizations of the sample properties. We study then the coherent backscattering cone properties as the relative permittivity of the sample is changed, relating the latter with the light localization inside the sample. We demonstrate important relationships between the width of the backscattering cone and the localization length, which shows a linear proportionality in the strong localization regime.

MC-50 AVF cyclotron operation

Energy Technology Data Exchange (ETDEWEB)

Chae, Jong Seo; Lee, Dong Hoon; Kim, You Seok; Park, Chan Won; Lee, Yong Min; Hong, Sung Seok; Lee, Min Yong

1995-12-01

The first cyclotron in Korea, MC-59 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-70 .mu.A. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed. (author). 8 tabs., 17 figs., 10 refs.

MC-50 AVF cyclotron operation

International Nuclear Information System (INIS)

Kim, Yu Seok; Chai, Jong Seo; Bak, Seong Ki; Park, Chan Won; Jo, Young Ho; Hong, Seong Seok; Lee, Min Yong; Jang Ho Ha

2000-01-01

The first cyclotron in Korea, MC-50 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-60μA. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23 days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed

MC-50 AVF cyclotron operation

Energy Technology Data Exchange (ETDEWEB)

Kim, Yu Seok; Chai, Jong Seo; Bak, Seong Ki; Park, Chan Won; Jo, Young Ho; Hong, Seong Seok; Lee, Min Yong; Jang Ho Ha

2000-01-01

The first cyclotron in Korea, MC-50 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-60{mu}A. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23 days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed.

MC-50 AVF cyclotron operation

International Nuclear Information System (INIS)

Chae, Jong Seo; Lee, Dong Hoon; Kim, You Seok; Park, Chan Won; Lee, Yong Min; Hong, Sung Seok; Lee, Min Yong.

1995-12-01

The first cyclotron in Korea, MC-59 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-70 .mu.A. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed. (author). 8 tabs., 17 figs., 10 refs

Building 211 cyclotron characterization survey report

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-30

The Building 211 Cyclotron Characterization Survey includes an assessment of the radioactive and chemical inventory of materials stored within the facility; an evaluation of the relative distribution of accelerator-produced activation products within various cyclotron components and adjacent structures; measurement of the radiation fields throughout the facility; measurement and assessment of internal and external radioactive surface contamination on various equipment, facility structures, and air-handling systems; and an assessment of lead (Pb) paint and asbestos hazards within the facility.

Cyclotron beam dynamic simulations in MATLAB

International Nuclear Information System (INIS)

Karamysheva, G.A.; Karamyshev, O.V.; Lepkina, O.E.

2008-01-01

MATLAB is useful for beam dynamic simulations in cyclotrons. Programming in an easy-to-use environment permits creation of models in a short space of time. Advanced graphical tools of MATLAB give good visualization features to created models. The beam dynamic modeling results with an example of two different cyclotron designs are presented. Programming with MATLAB opens wide possibilities of the development of the complex program, able to perform complete block of calculations for the design of the accelerators

Magnet design and test of positron emission tomography cyclotron

International Nuclear Information System (INIS)

Wei Tao; Yang Guojun; He Xiaozhong; Pang Jian; Zhao Liangchao; Zhang Kaizhi

2012-01-01

An 11 MeV H - compact cyclotron used for medical radioactive isotope production is under construction in Institute of Fluid Physics, CAEP. The cyclotron magnet adopts the design of small valley gaps and coulee structure which can provide high average magnetic field and strong focus ability. To achieve 5 × 10 -4 measuring accuracy, a magnetic field mapping system has been developed. After iterative correction using field measurement data, the total phase excursion of the cyclotron is within ± 9° and the first harmonic is less than 10 -3 T, which are all acceptable. Furthermore, the beam testing declares the successful construction of the cyclotron magnet. Besides, some magnetic field influence factors were discussed, including the magnetic field distortion and measurement error. (authors)

Studies of electron cyclotron emission on text

International Nuclear Information System (INIS)

Gandy, R.F.

1990-07-01

The Auburn University electron cyclotron emission (ECE) system has made many significant contributions to the TEXT experimental program during the past five years. Contributions include electron temperature information used in the following areas of study: electron cyclotron heating (ECH), pellet injection, and impurity/energy transport. Details of the role which the Auburn ECE system has played will now be discussed

Cyclotrons for the production of radioactive beams

International Nuclear Information System (INIS)

Clark, D.J.

1990-01-01

This paper describes the characteristics and design choices for modern cyclotrons. Cyclotrons can be used in 3 areas in the radioactive beam field: the production of high energy heavy ion beams for use in fragmentation, the spallation of targets with high energy protons, and the acceleration of radioactive beams from low energy to the MeV/u range. 16 refs., 6 figs

Wave fronts of electromagnetic cyclotron harmonic waves

International Nuclear Information System (INIS)

Ohnuma, T.; Watanabe, T.

1982-01-01

In an inhomogeneous high-density magnetized plasma, the spatial properties of the wave fronts and ray trajectories of electromagnetic ordinary and extraordinary cyclotron harmonic waves are investigated. Those waves which are radiated from a local source are found to have wave fronts which are almost parallel to the magnetic field. Also, the reflective properties of the electromagnetic cyclotron harmonic waves are confirmed

JSW's baby cyclotron

International Nuclear Information System (INIS)

Toda, Y.; Kaneda, Y.; Satoh, Y.; Suzukawa, I.; Yamada, T.

1983-01-01

Designed by The Japan Steel Works, Ltd., specially for installation in a hospital's medical department and nuclear research laboratory, '' JSW BABY CYCLOTRON '' has been developed to produce short-lived radioisotopes such as 11C, 13N, 15O and 18F. JSW's Baby Cyclotron has some design features. 1) Fixed energy and four sector azimuthally varying field. 2) Compact figure desired for hospital's nuclear medical department 3) A bitter type magnet yoke shielding activity 4) Simple control and operation 5) Easy maintenance without skilled personnel. Type BC105 (P:10MeV, d:5MeV), BC107 (P:10MeV, d:7MeV), BC168 (P:16MeV, d:8MeV) and BC1710 (P:17MeV, d:10MeV) are available according to required amount of radioisotopes. In our radioisotope production test, yield and purity of 11C, 13N, 15O and 18F are usable to clinical diagnosis

Cyclotron produced radiopharmaceuticals

International Nuclear Information System (INIS)

Kopicka, K.; Fiser, M.; Hradilek, P.; Hanc, P.; Lebeda, O.

2003-01-01

Some of the cyclotron-produced radionuclides may serve as important materials for the production of radiopharmaceuticals. This lecture deals with basic information relating to various aspects of these compounds. In comparison with radionuclides /compounds used for non-medical purposes, radiopharmaceuticals are subject to a broader scale of regulations, both from the safety and efficacy point of view; besides that, there are both radioactive and medical aspects that must be taken into account for any radiopharmaceutical. According to the regulations and in compliance with general rules of work with radioactivity, radiopharmaceuticals should only be prepared/manufactured under special conditions, using special areas and special equipment and applying special procedures (e.g. sterilisation, disinfection, aseptic work). Also, there are special procedures for cleaning and maintenance. Sometimes the requirements for the product safety clash with those for the safety of the personnel; several examples of solutions pertaining to these cases are given in the lecture. Also, the specific role of cyclotron radiopharmaceuticals is discussed. (author)

Surface investigations using monolayer-resolvable high-resolution Rutherford backscattering spectroscopy

International Nuclear Information System (INIS)

Kimura, Kenji; Ohtsuka, Hisashi; Ohshima, Kazuomi; Mannami, Michi-hiko

1994-01-01

Energy spectra of scattered 0.5 MeV He ions from a clean (001) surface of SnTe are measured with a 90 sector magnetic spectrometer (ΔE/E ∼ 0.1%). The ions scattered from successive atomic layers can be resolved in the energy spectra. Inelastic energy losses and charge state distributions of 0.5 MeV He ions scattered from the topmost atomic layer of the SnTe(001) are measured. A position-dependent stopping power at the surface is proposed from the observed energy losses. The observed charge state distribution shows the importance of the charge-exchange processes with valence electrons in the tail of the electron distribution at the surface. (orig.)

Effect of the cortex on ultrasonic backscatter measurements of cancellous bone

International Nuclear Information System (INIS)

Hoffmeister, Brent K; Holt, Andrew P; Kaste, Sue C

2011-01-01

Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

Effect of the cortex on ultrasonic backscatter measurements of cancellous bone

Energy Technology Data Exchange (ETDEWEB)

Hoffmeister, Brent K; Holt, Andrew P [Department of Physics, Rhodes College, Memphis, TN (United States); Kaste, Sue C, E-mail: hoffmeister@rhodes.edu [Department of Diagnostic Imaging, St Jude Children' s Research Hospital, Memphis, TN (United States)

2011-10-07

Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

Magnetization anomaly of Nb3Al strands and instability of Nb3Al Rutherford cables

International Nuclear Information System (INIS)

Yamada, Ryuji; Kikuchi, Akihiro; Wake, Masayoshi

2006-01-01

Using a Cu stabilized Nb 3 Al strand with Nb matrix, a 30 meter long Nb 3 Al Rutherford cable was made by a collaboration of Fermilab and NIMS. Recently the strand and cable were tested. In both cases instability was observed at around 1.5 Tesla. The magnetization of this Nb 3 Al strand was measured first using a balanced coil magnetometer at 4.2 K. Strands showed an anomalously large magnetization behavior around at 1.6 T, which is much higher than the usual B c2 ∼ 0.5 Tesla (4.2 K) of Nb matrix. This result is compared with the magnetization data of short strand samples using a SQUID magnetometer, in which a flux-jump signal was observed at 0.5 Tesla, but not at higher field. As a possible explanation for this magnetization anomaly, the interfilament coupling through the thin Nb films in the strands is suggested. The instability problem observed in low field tests of the Nb 3 Al Rutherford cables is attributed to this effect

Emergency situation in a medical cyclotron facility

International Nuclear Information System (INIS)

Kumar, Rajeev; Bhat, M.K.; Singh, D.K.; Pthania, B.S.; Pandit, A.G.; Jacob, M.J.

2010-01-01

Full text: Medical cyclotron is a particle accelerator used in producing short lived radioisotopes such as 18 F, 11 C, 15 O, 13 N, 18 F-2 gas etc. Positron Emission Tomography (PET) is a nuclear imaging modality that has rapidly gained favour. 18 F-FDG is the most widely used radiopharmaceutical with a half-life of 109.8 min. Having more than five years experience in this field we face lots of emergency conditions in the medical cyclotron facility. On the basis of harm we have divided in to three categories i.e. Harm of (a) working personnel, (b) Equipment and (c) environment. Radioactive gas leak and Target foil rupture is considered as the major emergency situations during medical cyclotron operations because there is a potential of over exposure to the working personnel. Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions. It is found that the induced activity in the target foil increases with its successive usages. Recommendations have also been made to reduce personal exposure while handling the radioactive gas leak and target foil rupture conditions

Characterization for rbs of Titanium Oxide thin films grown by Dip Coating in a coloidal suspension of nano structured Titanium Oxide

International Nuclear Information System (INIS)

Pedrero, E.; Vigil, E.; Zumeta, I.

1999-01-01

The depth of Titanium Oxide thin films grown by Dip Coating in a coloidal suspension of nano structured Titanium Oxide was characterized using Rutherford Backscattering Spectrometry. Film depths are compared in function of bath and suspension parameters

Status report on the cyclotron

International Nuclear Information System (INIS)

Kormany, Z.

2002-01-01

Complete text of publication follows. The operation of the cyclotron in 2001 was again concentrated to the usual 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 4300 hours, the breakdown periods amounted to 66 hours last year. The cyclotron was available for users during 3751 hours, the effectively used beam-on-target time is summarized in Table 1. The total time required for machine setup and beam tuning or spent waiting for the start of an irradiation was 272 hours. The control of the adjustable collimators applied in the beam transport system of the cyclotron was renewed during the winter maintenance period. They have been connected to the programmable logic controllers (PLC) and their new control code frees the operators from the long and slow manual setting process. The successful renewal of the control of this and other subsystems (cyclotron and beam transport power supplies) made lots of adjusting and measuring elements on the original control desk needless. To provide more space for the control PCs and remove all unnecessary devices, the unused part of the control desk has been dismantled. The short beam line used mainly for radiation hardness studies was equipped with a new oil-diffusion vacuum system during the summer maintenance. Its components are also connected to the PLC and the same automatic control has been provided like for the other vacuum stands of- the beam transport system. Another short beam line - basically a mirror image of the first one - has also been installed and successfully tested by trial irradiations. (R.P.)

Statistical fluctuations in cooperative cyclotron radiation

Science.gov (United States)

Anishchenko, S. V.; Baryshevsky, V. G.

2018-01-01

Shot noise is the cause of statistical fluctuations in cooperative cyclotron radiation generated by an ensemble of electrons oscillating in magnetic field. Autophasing time - the time required for the cooperative cyclotron radiation power to peak - is the critical parameter characterizing the dynamics of electron-oscillators interacting via the radiation field. It is shown that premodulation of charged particles leads to a considerable narrowing of the autophasing time distribution function for which the analytic expression is obtained. When the number of particles Ne exceeds a certain value that depends on the degree to which the particles have been premodulated, the relative root-mean-square deviation (RMSD) of the autophasing time δT changes from a logarithmic dependence on Ne (δT ∼ 1 / lnNe) to square-root (δT ∼ 1 /√{Ne }). A slight energy spread (∼4%) results in a twofold drop of the maximum attainable power of cooperative cyclotron radiation.

Decommissioning analyzis of a university cyclotron

International Nuclear Information System (INIS)

Eggermont, G.X.; Buls, N.; Hermanne, A.

1996-01-01

In the widespread use of some medical nuclear facilities, such as cyclotrons for isotope production, Life cycle analyzis, including decommissioning, was not taken into account. The structural materials of an accelerator and the concrete shielding of the bunker are activated by neutrons. This could yield a considerable volume of nuclear waste and needs radiation protection concern for occupational workers and the environment during some decennia. At the university of Brussels (WB) a prospective radiation protection and waste analyzis is being made for the later decommissioning of their cyclotron. Only few similar studies have been published. In Belgium future nuclear dismantling operations will be submitted to a radiation protection authorization procedure. Meanwhile the nuclear waste authorities insist on dismantling planning, including financial provisioning. An optimization exercise was made at the VUB-cyclotron, taking into account international trends to clearance levels for low level nuclear waste. Conceptual prevention opportunities e.g. selective material choice could be identified for future accelerator constructions. (author)

Cyclotron resonance cooling by strong laser field

International Nuclear Information System (INIS)

Tagcuhi, Toshihiro; Mima, Kunioka

1995-01-01

Reduction of energy spread of electron beam is very important to increase a total output radiation power in free electron lasers. Although several cooling systems of particle beams such as a stochastic cooling are successfully operated in the accelerator physics, these cooling mechanisms are very slow and they are only applicable to high energy charged particle beams of ring accelerators. We propose here a new concept of laser cooling system by means of cyclotron resonance. Electrons being in cyclotron motion under a strong magnetic field can resonate with circular polarized electromagnetic field, and the resonance take place selectively depending on the velocity of the electrons. If cyclotron frequency of electrons is equal to the frequency of the electromagnetic field, they absorb the electromagnetic field energy strongly, but the other electrons remain unchanged. The absorbed energy will be converted to transverse kinetic energy, and the energy will be dumped into the radiation energy through bremastrahlung. To build a cooling system, we must use two laser beams, where one of them is counter-propagating and the other is co-propagating with electron beam. When the frequency of the counter-propagating laser is tuned with the cyclotron frequency of fast electrons and the co-propagating laser is tuned with the cyclotron frequency of slow electrons, the energy of two groups will approach and the cooling will be achieved. We solve relativistic motions of electrons with relativistic radiation dumping force, and estimate the cooling rate of this mechanism. We will report optimum parameters for the electron beam cooling system for free electron lasers

Ion source and injection line for high intensity medical cyclotron

Science.gov (United States)

Jia, XianLu; Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang

2014-02-01

A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H- ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 μA/14 MeV was extracted from the cyclotron with a small multi-cusp H- ion source (CIAE-CH-I type) and a short injection line, which the H- ion source of 3 mA/25 keV H- beam with emittance of 0.3π mm mrad and the injection line of with only 1.2 m from the extraction of ion source to the medial plane of the cyclotron. To increase the extracted beam intensity of the cyclotron, a new ion source (CIAE-CH-II type) of 9.1 mA was used, with maximum of 500 μA was achieved from the cyclotron. The design and test results of the ion source and injection line optimized for high intensity acceleration will be given in this paper.

Cyclotron will not survive yet this year without state support

International Nuclear Information System (INIS)

Marcan, P.

2005-01-01

In this paper the project of the Cyclotron Center of the Slovak republic is described. On the basis of this project the state joint-stock company Biont was constituted. Small cyclotron is in operation; big cyclotron is in process of manufacture and it will be put in operation in 2007. Small cyclotron will be used for production of radiopharmaceuticals. Positron emission tomograph (PET) in Oncological Institute of St. Elizabeth (in Bratislava) and gamma camera in Central Military Hospital (in Ruzomberok) are constituents of the Biont. The PET will be also in Biont. The hadron therapy of ophthalmic tumors is planned. Financial plans of the Biont up to 2009 are presented

The problems of high efficient extraction from the isochronous cyclotron

International Nuclear Information System (INIS)

Schwabe, J.

1994-06-01

The problem of high efficient extraction (η ≥ 50%) from isochronous cyclotrons (with the exception of the stripping method) is not completely solved up to this day. This problem is specifically important, because these cyclotrons are being also applied in the production of medical radioisotopes, labeled pharmaceuticals as well as in neutron therapy (oncology), machine industry, agriculture (plant mutagenesis), etc. The aim of the proposed topic is to solve this problem on the AIC-144 isochronous cyclotron in the INP (Institute of Nuclear Physics). Lately, a beam of 20 MeV deuterons with an efficiency of ca. 15% was extracted from this cyclotron. (author). 25 refs, 14 figs

Quantitative characterization of abyssal seafloor with transit multibeam backscatter data

Science.gov (United States)

Pockalny, R. A.; Ferrini, V. L.

2014-12-01

The expanding volume of deep-water multibeam echosounder data provides emerging opportunities for the improved characterization of the abyssal seafloor. Nearly 500 cruises criss-cross the oceans with modern wide-swath multibeam systems, and these cruise tracks have imaged a variety of morphologic, tectonic and magmatic environments. The qualitative analysis of the seafloor backscatter data strongly suggests a local and regional variability that correlates with sediment thickness, sediment type and/or depositional environment. We present our initial attempts to develop a method that quantifies this observed seafloor backscatter variability and to explore the causes and potential implications of this variability. Our approach is rooted in the Angular Range Analysis methodology, which utilizes changes in backscatter amplitude observed as a function of grazing angle, to characterize the seafloor. The primary difference in our approach is that we do not invert for geo-acoustical parameters, but rather explores empirical relationships between geological observations and stacked slope and y-intercept values. In addition, we also include the mean and the variance of detrended backscatter measurements. Our initial results indicate intriguing relationships between backscatter parameters and the CaCO3 content of surface sediments. Seafloor regions reported to have high manganese nodule concentrations also tend to have characteristic trends in backscatter parameters. We will present these regional correlations as well as some preliminary statistical analyses of the backscatter parameters and key environmental factors.

Note on some quasielastic neutron scattering analysis programs on the Rutherford Laboratory IBM 360/195

International Nuclear Information System (INIS)

Richardson, R.M.

1979-12-01

A suite of programs for analysing neutron scattering data from time-of-flight spectrometers has been implemented on the Rutherford Laboratory IBM 360/195 computer system. The programs are intended for near inelastic and quasielastic data and operate by convoluting the measured instrumental resolution function with a model scattering function before fitting to the measured sample scattering law. (author)

Thermal Stabilization of Cryogenic System in Superconducting Cyclotron

International Nuclear Information System (INIS)

Shin, Seung Jae; Kim, Kyung Min; Cho, Hyung Hee; Hong, Bong Hwan; Kang, Joon Sun; Ahn, Dong Hyun

2011-01-01

Radiology has some useful applications for medical purpose. For cancer therapy, the superconducting cyclotron should generate heavy ion beams. It radiates heavy ion beams to cancer patients. In order to make cyclotron system stable, the cryogenic system which makes superconducting state should work constantly. However, radiation heat transfer of cryogenic system should be considered because liquid helium's boiling point is extremely low and there is huge temperature difference between the cryogenic system and ambient temperature. Accordingly, thermal analysis should be carried out. In this paper, the numerical analysis of the cryogenic system in practical superconducting cyclotron show temperature distribution and suggest the number of coolers using ANSYS Workbench program

The Cyclotron Center of the Slovak Republic

International Nuclear Information System (INIS)

Podhorsky, D.; Ruzicka, J.; Macasek, F.; Makaiova, I.; Saro, S.; Kristiak, J.; Fulup, M.

2001-01-01

The Cyclotron Center of the Slovak Republic was established at the beginning of August 1999 - within the Slovak-Office of Standards, Metrology and Testing (SOSMT), in Bratislava, Slovak Republic. It will have two cyclotrons - a large heavy and light cyclotron DC-72, which will be constructed by the Joint Institute for Nuclear Research (JINR), Dubna, Russian Federation, and a small commercial light ion cyclotron IBA 18/9. The heavy ion source of the electron resonance type (DECRS-2M) will be used for low and medium energy experiments in physics. The small electron accelerator is planned for different applications, including improving the properties of plastics, increasing the resistance of cables to fire and temperature, the sterilization of medical disposables in the CC SR. The main purpose of the Cyclotron Center of the Slovak Republic (CC SR) is to catch the present approach and trends in the area of improving of inhabitants life and health quality using the progressive technology, which is introduced by bringing into practice of the physical equipment - accelerators, producing beams of high energy particles. Experts of nuclear physics and of the related branches have no experimental basis in Slovakia, as after dissolution of the former the Czech and Slovak Federal Republic all bigger nuclear equipment were left in the Czech Republic. The Slovak Republic is one of the European countries where cancer and cardiovascular diseases have a rapidly increasing tendency (the rate of new oncological cases is approximately 20,000/year at the population of 5 million inhabitants) - early diagnostics of population is necessary to be updated urgently. The Slovak Republic use a great part of electricity (about 60 %) from its own nuclear power stations and thus it is in need of education of rising generations of experts from different nuclear fields. The Government of the Slovak republic on June 18, 1996 approved the strategic aim of building up the Cyclotron Laboratory at the

A radioisotope production cyclotron designed to minimize dose

International Nuclear Information System (INIS)

Szlavik, F.F.; Moritz, L.E.

1992-01-01

This paper describes a radioisotope production cyclotron which has been designed to minimize the dose to personnel during operation and maintenance. The design incorporates lessons learned from the operation of a CP42 cyclotron and has resulted in a reduction of the dose by a factor of more than 10. (author)

Cyclotron based nuclear science. Progress report, April 1, 1985-March 31, 1986

International Nuclear Information System (INIS)

Youngblood, D.H.

1986-08-01

Progress report for cyclotron based nuclear science cyclotron facility are summarized. Research is described under the headings heavy ion reactions, nuclear theory, atomic studies and activation analysis, superconducting cyclotron and instrumentation. Publications are listed

Health physics aspects of the 1.5M cyclotron

International Nuclear Information System (INIS)

Song, W.J.; Du, H.L.; Wei, Z.Q.; Xia, X.S.; Zheng, H.Z.; Jiang, G.F.; Liu, Y.Y.

1987-01-01

The 1.5m cyclotron in Institute of Modern Physics, Academia Sinica had operated for about 20 years until 1984 then converted to 1.7m sector focusing cyclotron. In this period it mainly used for fast neutron physics, light ion induced nucleus reactions, radioisotope production and heavy ion reactions. The health physics performed on this cyclotron including personnel dose monitoring, area monitoring (radiation field, radioactive aerosol, surface contamination and activated components etc.), maintenance inspection, environment survey and waste disposal is presented in this paper

Electromagnetic Ion Cyclotron Waves in the Helium Branch Induced by Multiple Electromagnetic Ion Cyclotron Triggered Emissions

Science.gov (United States)

Shoji, M.; Omura, Y.; Grison, B.; Pickett, J. S.; Dandouras, I. S.; Engebretson, M. J.

2011-12-01

Electromagnetic ion cyclotron (EMIC) triggered emissions with rising tones between the H+ and He+ cyclotron frequencies were found in the inner magnetosphere by the recent Cluster observations. Another type of EMIC wave with a constant frequency is occasionally observed below the He+ cyclotron frequency after the multiple EMIC triggered emissions. We performed a self-consistent hybrid simulation with a one-dimensional cylindrical magnetic flux model approximating the dipole magnetic field of the Earth's inner magnetosphere. In the presence of energetic protons with a sufficient density and temperature anisotropy, multiple EMIC triggered emissions are reproduced due to the nonlinear wave growth mechanism of rising-tone chorus emissions, and a constant frequency wave in the He+ EMIC branch is subsequently generated. Through interaction with the multiple EMIC rising-tone emissions, the velocity distribution function of the energetic protons is strongly modified. Because of the pitch angle scattering of the protons, the gradient of the distribution in velocity phase space is enhanced along the diffusion curve of the He+ branch wave, resulting in the linear growth of the EMIC wave in the He+ branch.

Risk assessment of 30 MeV cyclotron facilities

Energy Technology Data Exchange (ETDEWEB)

Jeong, Gyo Seong; Lee, Jin Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Chong Yeal [Dept. of Radiation Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of)

2017-03-15

A cyclotron is a kind of particle accelerator that produces a beam of charged particles for the production of medical, industrial, and research radioisotopes. More than 30 cyclotrons are operated in Korea to produce 18F, an FDG synthesis at hospitals. A 30-MeV cyclotron was installed at ARTI (Advanced Radiation Technology Institute, KAERI) mainly for research regarding isotope production. In this study, we analyze and estimate the items of risk such as the problems in the main components of the cyclotron, the loss of radioactive materials, the leakage of coolant, and the malfunction of utilities, fres and earthquakes. To estimate the occurrence frequency in an accident risk assessment, five levels, i.e., Almost certain, Likely, Possible, Unlikely, and Rare, are applied. The accident consequence level is classified under four grades based on the annual permissible dose for radiation workers and the public in the nuclear safety law. The analysis of the accident effect is focused on the radioactive contamination caused by radioisotope leakage and radioactive material leakage of a ventilation filter due to a free. To analyze the risks, Occupation Safety and Health Acts is applied. In addition, action plans against an accident were prepared after a deep discussion among relevant researchers. In this acts, we will search for hazard and introduce the risk assessment for the research 30-MeV cyclotron facilities of ARTI.

Risk assessment of 30 MeV cyclotron facilities

International Nuclear Information System (INIS)

Jeong, Gyo Seong; Lee, Jin Woo; Kim, Chong Yeal

2017-01-01

A cyclotron is a kind of particle accelerator that produces a beam of charged particles for the production of medical, industrial, and research radioisotopes. More than 30 cyclotrons are operated in Korea to produce 18F, an FDG synthesis at hospitals. A 30-MeV cyclotron was installed at ARTI (Advanced Radiation Technology Institute, KAERI) mainly for research regarding isotope production. In this study, we analyze and estimate the items of risk such as the problems in the main components of the cyclotron, the loss of radioactive materials, the leakage of coolant, and the malfunction of utilities, fres and earthquakes. To estimate the occurrence frequency in an accident risk assessment, five levels, i.e., Almost certain, Likely, Possible, Unlikely, and Rare, are applied. The accident consequence level is classified under four grades based on the annual permissible dose for radiation workers and the public in the nuclear safety law. The analysis of the accident effect is focused on the radioactive contamination caused by radioisotope leakage and radioactive material leakage of a ventilation filter due to a free. To analyze the risks, Occupation Safety and Health Acts is applied. In addition, action plans against an accident were prepared after a deep discussion among relevant researchers. In this acts, we will search for hazard and introduce the risk assessment for the research 30-MeV cyclotron facilities of ARTI

Ocean subsurface particulate backscatter estimation from CALIPSO spaceborne lidar measurements

Science.gov (United States)

Chen, Peng; Pan, Delu; Wang, Tianyu; Mao, Zhihua

2017-10-01

A method for ocean subsurface particulate backscatter estimation from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite was demonstrated. The effects of the CALIOP receiver's transient response on the attenuated backscatter profile were first removed. The two-way transmittance of the overlying atmosphere was then estimated as the ratio of the measured ocean surface attenuated backscatter to the theoretical value computed from wind driven wave slope variance. Finally, particulate backscatter was estimated from the depolarization ratio as the ratio of the column-integrated cross-polarized and co-polarized channels. Statistical results show that the derived particulate backscatter by the method based on CALIOP data agree reasonably well with chlorophyll-a concentration using MODIS data. It indicates a potential use of space-borne lidar to estimate global primary productivity and particulate carbon stock.

Determination of ion track and shapes with damage simulations on the base of ellipsometric and backscattering spectrometric measurements

Energy Technology Data Exchange (ETDEWEB)

Polgar, O.; Fried, M.; Khanh, N.; Petrik, P.; Barsony, I. [Research Institute for Technical Phisycs and Materials Science, Budapest (Hungary)

2008-05-15

On the base of geometrical and statistical considerations a damage simulator was created in order to determine the ion track-radius and -shape of ion-implantation caused damage in single-crystalline Si. Damage vs. dose curves calculated by spectroscopic ellipsometry (SE) and Rutherford backscattering/channeling spectrometry (RBS/C) measurements, using different doses of 100 keV Xe implantation, gave information about the damage profile in depth. Both methods are required, because of dose-dependent discrepancies of SE compared with RBS/C [Fried et al., Thin Solid Films 455/456, 404 (2004)]. Different kinds of damage models were investigated to calculate the ion track-radius and to describe the damages in depth and the shape of ion track. Comparing directly the simulated and the measured damage vs. dose curves, the damage function and the other simulation parameters were optimized and hence the ion track size and even the shape can be determined. The dose dependent mean size of the unchanged crystalline regions, obtained from the simulation was correlated with the complex dielectric functions, obtained from the SE analysis. The results clearly show the effect of decreasing size of the unchanged crystalline regions. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Radiation protection problems by the operation of the cyclotron facility

International Nuclear Information System (INIS)

Durcik, M.; Nikodemova, D.

1998-01-01

The Cyclotron Center in Bratislava will consist of two cyclotrons. First - cyclotron DC-72 with maximal energy of 72 MV for protons for making experiments, for teaching process, for radioisotope production as 123 I and for neutron and proton therapy. Second - compact cyclotron with maximal proton energy of 18 MeV will be used for radioisotopes production for medical diagnosis as 1 *F (fluorodeoxyglucose), 81 Rb/ 81 Kr generator. This paper deals with the radiation protection problems by the operation of tis cyclotron facility as radiation protection of workers, monitoring plan, ventilation, safety lock and limitation and radiation monitoring. For proposed and continuing practices at the accelerator facility, the following general principles have to be fulfilled: (1) practices should produce sufficient benefit to offset the radiation detriment they case (justification); (2) the magnitude of the individual doses should be kept as low as achievable (optimization of protection); (3) individual exposures are subject to dose limits and some control of risk from potential exposures (dose and risk limits)

Improvements in backscatter measurement devices

International Nuclear Information System (INIS)

Saunders, J.; Hay, W.D.

1978-01-01

Improvements in measuring the thickness of a coating on a substrate by the technique of backscattered particles are described. These improvements enable the measurements to be carried out continuously as an integral part of the coating production line and also permit measurements where the coated elements are separated from one another by a predetermined distance. The former is achieved by situating the backscatter probe and detector on the rim of the measurement wheel and rotating this wheel at a speed such that the coated element and probe are stationary relative to one another. The latter improvement is achieved by an indexing apparatus which automatically positions the probe beside a coated element. (U.K.)

A 30 MeV H- cyclotron for isotope production

International Nuclear Information System (INIS)

Milton, B.F.; Dawson, R.; Erdman, K.L.

1989-05-01

Because of an expanding market for radioisotopes there is a need for a new generation of cyclotrons designed specifically for this purpose. TRIUMF is cooperating with a local industrial company in designing and constructing such a cyclotron. It will be a four sector H - cyclotron, exploiting the newly developed high brightness multicusp ion source. This source with H - current capability in excess of 5 mA makes feasible accelerated H - beam intensities of up to 500 μA. Beam extraction is by stripping to H + in a thin graphite foil. Extraction of two high-intensity beams, with energy variable from 15 to 30 MeV is planned. The use of an external ion source, provision of a good vacuum in the acceleration region, and the careful choice of materials for components in the median plane leads to a cyclotron that will have low activation and can be easily serviced in spite of the very high operating beam intensities. A design extension to 70 MeV using many of the design features of the 30 MeV cyclotron can be easily made. Such a machine with a good quality variable energy beam is a highly desirable source of protons for isotope production, injection into higher energy high intensity acceleration, injection into higher energy high intensity accelerators, and as an irradiation facility for ocular melanomas. Design of the 30 MeV cyclotron is well advanced and construction is in progress

Ion-Beam-Excited Electrostatic Ion Cyclotron Waves

DEFF Research Database (Denmark)

Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

1976-01-01

Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field.......Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field....

Calculation of particle dynamics in CI-10 cyclotron

International Nuclear Information System (INIS)

Samsonov, E.V.; Karamysheva, G.A.; Vorozhtsov, S.B.

1999-01-01

The calculations of beam dynamic characteristics of High-Intensity Cyclotron-Injector CI-10 for deuteron beam of 15 MeV energy are presented. Analytical estimations of space charge effects are given. In order to increase the intensity of the accelerator beam some ideas about the cyclotron design modification are given too. (author)

Proton RBS measurement of the oxygen in heavy-metal oxides

International Nuclear Information System (INIS)

Xie, T.; Ryan, S.R.; Fischbeck, H.J.

1989-01-01

Although the stoichoimetry of high-T c superconductors is often measured using alpha-particle RBS, the small Rutherford cross section for oxygen relative to the high-Z components makes a determination of the oxygen content difficult. Above 1 MeV, the cross section for proton backscattering from oxygen becomes significantly greater than the Rutherford cross section. Studies of proton backscattering in CuO between 0.6 and 2.0 MeV show that it is possible to measure the oxygen content of high-Z metal oxides. RBS simulations using the Bragg-rule stopping power consistently underestimate the low-energy yield. Scaling the stopping power by a linear function of energy to reduce loss at low energy improves the simulation in CuO, Cu and Au. This general result suggests that the standard RBS simulation procedure may omit some relevant physics. (orig.)

Design of RF system for CYCIAE-230 superconducting cyclotron

Energy Technology Data Exchange (ETDEWEB)

Yin, Zhiguo, E-mail: bitbearAT@hotmail.com; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

2017-05-11

The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push–pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

Design of RF system for CYCIAE-230 superconducting cyclotron

Science.gov (United States)

Yin, Zhiguo; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

2017-05-01

The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push-pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

Biomedical cyclotron facility

International Nuclear Information System (INIS)

MacDonald, N.S.; Birdsall, R.; Takahaski, J.; McConnel, L.; Wood, R.; Wakakuwa, S.

1976-01-01

During the fifth year of operation the mechanical performance of the cyclotron and accessory equipment was excellent. Major items put into operation were a small computer system interfaced with Ge-Li gamma spectrometer and a pneumatic-tube system for fast delivery of short-lived radionuclides. A table is presented listing the radionuclides produced

Proceedings of eighth joint workshop on electron cyclotron emission and electron cyclotron resonance heating. Vol. 1

International Nuclear Information System (INIS)

1993-03-01

The theory of electron cyclotron resonance phenomena is highly developed. The main theoretical tools are well established, generally accepted and able to give a satisfactory description of the main results obtained in electron cyclotron emission, absorption and current drive experiments. In this workshop some advanced theoretical and numerical tools have been presented (e.g., 3-D Fokker-Planck codes, treatment of the r.f. beam as a whole, description of non-linear and finite-beam effects) together with the proposal for new scenarios for ECE and ECA measurements (e.g., for diagnosing suprathermal populations and their radial transport). (orig.)

Proceedings of eighth joint workshop on electron cyclotron emission and electron cyclotron resonance heating. Vol. 2

International Nuclear Information System (INIS)

1993-03-01

The theory of electron cyclotron resonance phenomena is highly developed. The main theoretical tools are well established, generally accepted and able to give a satisfactory description of the main results obtained in electron cyclotron emission, absorption and current drive experiments. In this workshop some advanced theoretical and numerical tools have been presented (e.g., 3-D Fokker-Planck codes, treatment of the r.f. beam as a whole, description of non-linear and finite-beam effects) together with the proposal for new scenarios for ECE and ECA measurements (e.g., for diagnosing suprathermal populations and their radial transport). (orig.)

Modification of the iron mechanical- and corrosion features by ion implantation in surface

International Nuclear Information System (INIS)

Baumvol, I.J.R.

1981-01-01

The physical mechanisms responsable by the tin ion implantation in the iron surface at moderated doses are studied. Several techniques are used such as alpha-particle Rutherford backscattering, conversion electron Moessbauer spectroscopy and scanning electron microscopy. (L.C.) [pt

Vacancy-acceptor complexes in germanium produced by ion implantation

Energy Technology Data Exchange (ETDEWEB)

Feuser, U.; Vianden, R. (Inst. fuer Strahlen- und Kernphysik, Univ. Bonn (Germany)); Alves, E.; Silva, M.F. da (Dept. de Fisica, ICEN/LNETI, Sacavem (Portugal)); Szilagyi, E.; Paszti, F. (Central Research Inst. for Physics, Hungarian Academy of Sciences, Budapest (Hungary)); Soares, J.C. (Centro de Fisica Nuclear, Univ. Lisbon (Portugal))

1991-07-01

Combining results obtained by the {gamma}-{gamma} perturbed angular correlation method, Rutherford backscattering and elastic recoil detection of hydrogen, a defect complex formed in germanium by indium implantation is identified as a vacancy trapped by the indium probe. (orig.).

Identification of major backscattering sources in trees and shrubs at 10 GHz

Science.gov (United States)

Zoughi, R.; Wu, L. K.; Moore, R. K.

1986-01-01

A short-range very-fine-resolution FM-CW radar scatterometer has been used to identify the primary contributors to 10-GHz radar backscatter from pine, pin oak, American sycamore and sugar maple trees, and from creeping juniper shrubs. This system provided a range resolution of 11 cm and gave a 16-cm diameter illumination area at the target range of about 4 m. For a pine tree, the needles caused the strongest backscatter as well as the strongest attenuation in the radar signal. Cones, although insignificant contributors to the total backscatter, were more important for backscattering than for attenuation. For the rest of the trees, leaves were the strongest cause of backscattering and attenuation. However, in the absence of leaves, the petioles, small twigs, and branches gave relatively strong backscatter. For American sycamore and sugar maple trees, the fruits did not affect the total backscatter unless they were packed in clusters. For creeping juniper the backscattered energy and attenuation in the radar signal were mainly due to the top two layers of the evergreen scales. The contribution of the tree trunks was not determined.

BATS - Backscattering And Time-of-flight Spectrometer

International Nuclear Information System (INIS)

Van Eijck, L.; Seydel, T.; Frick, B.; Schober, H.

2011-01-01

The new backscattering spectrometer IN16b will go into commissioning end 2011, providing in its final state about ten times higher count rate than its predecessor, IN16. Here we propose to increase its dynamic range by a factor of 7 with the TOF mode extension, BATS. This will make IN16b the leading high resolution backscattering spectrometer for incoherent quasi-elastic and inelastic neutron scattering; it will be competitive to the coarser resolution inverted geometry backscattering spectrometers that are being brought online at spallation sources. The increased dynamic range will extend the scope of science addressed on IN16b, generating considerable potential in fields such as the hydrogen economy (proton conduction, fuel cells, hydrogen storage), soft matter, biology and nano-science (nano-scale confinement, functionalized polymers). Such a large impact can be achieved using only a moderate investment. (authors)

Automated cyclotron tuning using beam phase measurements

International Nuclear Information System (INIS)

Timmer, J.H.; Roecken, H.; Stephani, T.; Baumgarten, C.; Geisler, A.

2006-01-01

The ACCEL K250 superconducting cyclotron is specifically designed for the use in proton therapy systems. The compact medical 250 MeV proton accelerator fulfils all present and future beam requirements for fast scanning treatment systems and is delivered as a turn key system; no operator is routinely required. During operation of the cyclotron heat dissipation of the RF system induces a small drift in iron temperature. This temperature drift slightly detunes the magnetic field and small corrections must be made. A non-destructive beam phase detector has been developed to measure and quantify the effect of a magnetic field drift. Signal calculations were made and the design of the capacitive pickup probe was optimised to cover the desired beam current range. Measurements showed a very good agreement with the calculated signals and beam phase can be measured with currents down to 3 nA. The measured phase values are used as input for a feedback loop controlling the current in the superconducting coil. The magnetic field of the cyclotron is tuned automatically and online to maintain a fixed beam phase. Extraction efficiency is thereby optimised continuously and activation of the cyclotron is minimised. The energy and position stability of the extracted beam are well within specification

A visual assistance environment for cyclotron operation

International Nuclear Information System (INIS)

Okamura, Tetsuya; Murakami, Tohru; Agematsu, Takashi; Okumura, Susumu; Arakawa, Kazuo.

1993-01-01

A computer-based operation system for a cyclotron which assists inexperienced operators has been developed. Cyclotron start-up operations require dozens of adjustable parameters to be finely tuned to maximize extracted beam current. The human interfaces of the system provide a visual environment designed to enhance beam parameter adjustments. First, the mental model of operators is analyzed. It is supposed to be composed of five partial mental models: beam behavior model, feasible setting regions model, parameter sensitivity model, parameter mutual relation model, and status map model. Next, based on these models, three visual interfaces are developed, i.e., (1) Beam trajectory is rapidly calculated and graphically displayed whenever the operators change the cyclotron parameters. (2) Feasible setting regions (FSR) of the parameters that satisfy the cyclotron's beam acceptance criteria are indicated. (3) Search traces, being a historical visual map of beam current values, are superimposed on the FSRs. Finally, to evaluate system effectiveness, the search time required to reach maximum beam current conditions was measured. In addition, system operability was evaluated using written questionnaires. Results of the experiment showed that the search time to reach specific beam conditions was reduced by approximately 65% using these interfaces. The written questionnaires survey showed the operators highly evaluate system operability. (author)

Radiation safety and operational health physics of hospital based medical cyclotrons

International Nuclear Information System (INIS)

Mukherjee, B.

2002-01-01

Full text: Compact, low energy, high current Medical Cyclotrons are now primarily used to produce large activities of short lived, neutron deficient, positron- emitting radioisotopes. These isotopes constitute the key ingredients of important PET (Positron Emission Tomography) radiopharmaceuticals used in diagnostic nuclear medicine. The PET-radioisotope producing Medical Cyclotrons are now increasingly installed in modern urban hospitals in many countries of the world. Modern Medical Cyclotrons run at a very high beam current (∼100-200 micro Amp) level and thereby produce intense fields of parasitic gamma rays and neutrons, causing the activation of cyclotron components, ambient air and radiation exposure to patients and members of the public. This report highlights the important operational aspects and the characteristics of the radiation fields produced by Medical Cyclotrons. The pathways of personnel radiation exposure are also analyzed. The above information constitutes the scientific basis of a sound operational health physics service, which is manifested in an effective dose reduction and an enhanced radiological safety of the Medical Cyclotron facility within the framework of ALARA

Radiation shielding analysis of medical cyclotron at Radiation Medicine Centre, Parel

International Nuclear Information System (INIS)

Gathibandhe, M.V.; Agrawal, R.A.; Utge, C.G.

2003-01-01

Full text: PET (Positron Emission Tomography) is a diagnostic method to obtain 3-D functional images of the distribution of radio-nuclides introduced in the human body as tracers for specific biological processes. Tracers are produced by bombardment of different target nuclides by protons and deuterons of high energy produced in the cyclotron. A Wipro-GE medical cyclotron was installed in the basement of RMC, Parel. Shielding around the cyclotron is provided in the form of borated concrete walls of required thickness to limit dose rates to design values as per AERB criteria. The roof of the cyclotron room is made of heavy concrete. Entry in to the room is through a maze. Shielding analysis for the cyclotron room has been carried out using computer code ANISN. The maze has been analyzed using code MCNP. Based on the analysis carried out additional shielding was recommended to meet the design requirements. The paper discusses the shielding analysis carried out for the cyclotron room and the maze. Dose rate estimated at various locations are highlighted

Simulation of the cabling process for Rutherford cables: An advanced finite element model

Science.gov (United States)

Cabanes, J.; Garlasche, M.; Bordini, B.; Dallocchio, A.

2016-12-01

In all existing large particle accelerators (Tevatron, HERA, RHIC, LHC) the main superconducting magnets are based on Rutherford cables, which are characterized by having: strands fully transposed with respect to the magnetic field, a significant compaction that assures a large engineering critical current density and a geometry that allows efficient winding of the coils. The Nb3Sn magnets developed in the framework of the HL-LHC project for improving the luminosity of the Large Hadron Collider (LHC) are also based on Rutherford cables. Due to the characteristics of Nb3Sn wires, the cabling process has become a crucial step in the magnet manufacturing. During cabling the wires experience large plastic deformations that strongly modify the geometrical dimensions of the sub-elements constituting the superconducting strand. These deformations are particularly severe on the cable edges and can result in a significant reduction of the cable critical current as well as of the Residual Resistivity Ratio (RRR) of the stabilizing copper. In order to understand the main parameters that rule the cabling process and their impact on the cable performance, CERN has developed a 3D Finite Element (FE) model based on the LS-Dyna® software that simulates the whole cabling process. In the paper the model is presented together with a comparison between experimental and numerical results for a copper cable produced at CERN.

Calculation of proton beam initial orbit at cyclotron central region

International Nuclear Information System (INIS)

Pramudita Anggraita

2012-01-01

A calculation of proton beam initial orbits at cyclotron central region was carried out using Scilab 5.2.0. The calculation was done in 2 dimensions in a homogeneous magnetic field of 1.66 tesla at frequency of fourth harmonics. The positions of ion source, dees, and dummy dees follow those of GE Minitrace cyclotron, peak dee voltage 30 kV. The calculation yields result comparable to those simulated at KIRAMS-13 cyclotron. (author)

The establishment of the Blacknest seismological database on the Rutherford Laboratory system 360/195 computer

International Nuclear Information System (INIS)

Blamey, C.

1977-01-01

In order to assess the problems which might arise from monitoring a comprehensive test ban treaty by seismological methods, an experimental monitoring operation is being conducted. This work has involved the establishment of a database on the Rutherford Laboratory 360/195 system computer. The database can be accessed in the UK over the public telephone network and in the USA via ARPANET. (author)

The development of cyclotron radiopharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

Yang, Seung Dae; Chun, K. W.; Suh, Y. S.; Lee, J. D.; Ahn, S. H. and others

1999-03-01

The purpose of this project is to developthe radiopharmaceuticals and automatic synthetic unit for labelled compounds, and to establish mass production system of radiopharmaceuticals. These will contribute to the early diagnosis of the disease hard to cure. The contents of this project are as follows, the development of the radiopharmaceutical for imaging of cancer, the development of automatic synthesizer for the synthesis of radio-pharmaceuticals, the development of hormone derivatives labelled with {sup 12}'3I, the development of the radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for imaging of myocardial metabolism.

The development of cyclotron radiopharmaceuticals

International Nuclear Information System (INIS)

Yang, Seung Dae; Chun, K. W.; Suh, Y. S.; Lee, J. D.; Ahn, S. H. and others

1999-03-01

The purpose of this project is to develop the radiopharmaceuticals and automatic synthetic unit for labelled compounds, and to establish mass production system of radiopharmaceuticals. These will contribute to the early diagnosis of the disease hard to cure. The contents of this project are as follows, the development of the radiopharmaceutical for imaging of cancer, the development of automatic synthesizer for the synthesis of radio-pharmaceuticals, the development of hormone derivatives labelled with 12 '3I, the development of the radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for imaging of myocardial metabolism

Electromagnetic ion cyclotron waves observed near the oxygen cyclotron frequency by ISEE 1 and 2

International Nuclear Information System (INIS)

Fraser, B.J.; Samson, J.C.; Hu, Y.D.; McPherron, R.L.; Russell, C.T.

1992-01-01

Pc 2 electromagnetic ion cyclotron waves at 0.1 waves at 0.1 Hz, near the oxygen cyclotron frequency, have been observed by ISEE 1 and 2 between L = 7.6 and 5.8 on an inbound near-equatorial pass in the dusk sector. The waves occurred in a thick plasmapause of width ∼ 1.5 R E and penetrated ∼1 R E into the plasmasphere. Wave onset was accompanied by significant increases in the thermal (0-100 eV) He + and the warm (0.1-16 keV/e) O + and He + heavy ion populations. The most intense waves (8 nT) were observed in the outer plasmasphere where convection drift velocities (E x B)/B 2 were largest and the Alfven velocity was a minimum. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by cold plasma propagation theory are identified in the wave data. Poynting fluxes calculated during the first 15 min of the event show wave energy propagation directions both parallel and antiparallel to the field. Computations of the experimental wave spectra during the passage through the plasmapause show that the spectral slots relate to local plasma parameters, possibly suggesting an ion cyclotron wave growth source near the spacecraft. A regular wave packet structure seen over the first 30 min of the event may be attributed to the modulation of this energy source by the Pc 5 waves seen at the same time. Overall, the results are considered an example of an electromagnetic ion cyclotron wave-particle interaction occurring during the outer plasmasphere refilling process at the time of the substorm recovery phase

A surface science model for the Phillips ethylene polymerization catalyst : thermal activation and polymerization activity

NARCIS (Netherlands)

Kimmenade, van E.M.E.; Kuiper, A.E.T.; Tamminga, Y.; Thuene, P.C.; Niemantsverdriet, J.W.

2004-01-01

A series of CrOx/SiO2/Si(100) model catalysts were tested for ethylene polymerization activity, varying chromium loading, and calcination temperature. Chromium coverage of the model catalyst, quantified by Rutherford backscattering spectrometry, decreases with increasing calcination temperature as

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

Digital Repository Service at National Institute of Oceanography (India)

Fernandes, W.A.; Chakraborty, B.

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

The Rutherford Appleton Laboratory's Mark I Multiwire Proportional Counter positron camera

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Tappern, G.J.; Flesher, A.C.

1983-01-01

A small model of a proposed large aperture positron camera has been developed at Rutherford Appleton Laboratory. Based on Multiwire Proportional Counter technology it uses lead foil cathodes which function simultaneously as converters for the 511 keV gamma rays and readout electrodes for a delay line readout system. The detectors have been built up into a portable imaging system complete with a dedicated computer for data taking, processing and display. A complete hardware system and sufficient software was provided to permit hospital based colleagues to generate useful images easily. A complete description of the system is given with performance figures and some of the images obtained are presented. (author)

Heating tokamaks via the ion-cyclotron and ion-ion hybrid resonances

International Nuclear Information System (INIS)

Perkins, F.W.

1977-04-01

For the ion-ion hybrid resonance it is shown that: (1) the energy absorption occurs via a sequence of mode conversions; (2) a poloidal field component normal to the ion-ion hybrid mode conversion surface strongly influences the mode conversion process so that roughly equal electron and ion heating occurs in the present proton-deuterium experiments, while solely electron heating is predicted to prevail in deuterium-tritium reactors; (3) the ion-ion hybrid resonance suppresses toroidal eigenmodes; and (4) wave absorption in minority fundamental ion-cyclotron heating experiments will be dominated by ion-ion hybrid mode conversion absorption for minority concentrations exceeding roughly 1 percent. For the ion-cyclotron resonance, it is shown that: (1) ion-cyclotron mode conversion leads to surface electron heating; and (2) ion-cyclotron mode conversion absorption dominates fundamental ion-cyclotron absorption thereby preventing efficient ion heating

Ion Cyclotron Resonance Facility (ICR)

Data.gov (United States)

Federal Laboratory Consortium — his facility is charged with developing and exploiting the unique capabilities of Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry, and leads the...

Present status of device controls and hardware interfaces for the RCNP ring cyclotron

International Nuclear Information System (INIS)

Yamazaki, T.; Tamura, K.; Hosono, K.

1994-01-01

Since the first proton beam from the injector AVF cyclotron was injected to the ring cyclotron in 1991, the computer control system has been used for the beam acceleration of the ring cyclotron. Some device control modules have been updated, and computer configuration has been changed in 1992. Total control system performs basic facilities almost satisfactory under actual cyclotron operation. (author)

Cyclotron based nuclear science: Progress report, April 1, 1987-March 31, 1988

International Nuclear Information System (INIS)

1988-08-01

This report discusses experiment run on the K500 cyclotron and 88 in cyclotron at Texas AandM University. The main topics of these experiments are: Heavy ion reactions; Nuclear structure and fundamental interactions; Atomic and material science; Nuclear theory; and Superconducting cyclotron and instrumentation

The PET / cyclotron facility at Putrajaya Hospital - an update

International Nuclear Information System (INIS)

Siti Najila Mohd Janib; Suzilawati Muhd Sarowi; Munira Shaikh Nasir; Zulkifli Mohamed Hashim

2006-01-01

Malaysia desire to have a cyclotron for nuclear medical use came into realisation recently with the establishment of a PET/Cyclotron Facility at Putrajaya Hospital. The testing and commissioning of the cyclotron, hot cells, QC equipment and PET/CT started on March 27, culminating in the first patient to be injected on May 10 2006. Three other patients were to be followed on May 15. The patients from both the Kuala Lumpur and Putrajaya Hospital were pre-selected by physicians from these hospitals. The 18 MeV cyclotron is capable of generating 16.4 MeV protons and 8.4 MeV deuterons. The cyclotron at Putrajaya has three targets (2 liquid and 1 gas) and is capable of producing 18 F-FDG and 18 F-DOPA. To complement this, the facility has 2 modules for FDG synthesis, 1 for F-DOPA and 1 for nucleophilic synthesis. The facility will be GMP compliant. For the first production for human use, the water-18 target was irradiated for 50 minutes at 20 mA to produce 1.3 Ci of F-18. At the end of synthesis, the activity of the FDG obtained was 600 mCi. The product was then injected to a 26-year-old female, with a suspected adenocarcinoma. (Author)

A full-angle Monte-Carlo scattering technique including cumulative and single-event Rutherford scattering in plasmas

Science.gov (United States)

Higginson, Drew P.

2017-11-01

We describe and justify a full-angle scattering (FAS) method to faithfully reproduce the accumulated differential angular Rutherford scattering probability distribution function (pdf) of particles in a plasma. The FAS method splits the scattering events into two regions. At small angles it is described by cumulative scattering events resulting, via the central limit theorem, in a Gaussian-like pdf; at larger angles it is described by single-event scatters and retains a pdf that follows the form of the Rutherford differential cross-section. The FAS method is verified using discrete Monte-Carlo scattering simulations run at small timesteps to include each individual scattering event. We identify the FAS regime of interest as where the ratio of temporal/spatial scale-of-interest to slowing-down time/length is from 10-3 to 0.3-0.7; the upper limit corresponds to Coulomb logarithm of 20-2, respectively. Two test problems, high-velocity interpenetrating plasma flows and keV-temperature ion equilibration, are used to highlight systems where including FAS is important to capture relevant physics.

Progress report on the Milan superconducting cyclotron

International Nuclear Information System (INIS)

Acerbi, E.; Alessandria, F.; Baccaglioni, G.; Bellomo, G.; Birattari, C.; Bosotti, A.; Broggi, F.; Cortesi, G.; DeMartinis, C.; Fabrici, E.; Ferrari, A.; Giove, D.; Giussani, A.; Giussani, W.; Michelato, P.; Pagani, C.; Rivoltella, G.; Rossi, L.; Serafini, L.; Sussetto, A.; Torri, V.; Varisco, G.; Cuttone, G.; Raia, G.; Kai, L.

1988-01-01

This paper reports on the construction of the K800 superconducting cyclotron at the University of Milan underway since February 1981. The delay in the construction of the new building and a defect of the weldings of the helium vessel have caused a shift in the project schedule of about two years. Currently, the cyclotron magnet and the cryogenic plant have been completed and installed. First operation of the magnet and magnetic field mapping are to begin shortly

Scientific instruments, scientific progress and the cyclotron

International Nuclear Information System (INIS)

Baird, David; Faust, Thomas

1990-01-01

Philosophers speak of science in terms of theory and experiment, yet when they speak of the progress of scientific knowledge they speak in terms of theory alone. In this article it is claimed that scientific knowledge consists of, among other things, scientific instruments and instrumental techniques and not simply of some kind of justified beliefs. It is argued that one aspect of scientific progress can be characterized relatively straightforwardly - the accumulation of new scientific instruments. The development of the cyclotron is taken to illustrate this point. Eight different activities which promoted the successful completion of the cyclotron are recognised. The importance is in the machine rather than the experiments which could be run on it and the focus is on how the cyclotron came into being, not how it was subsequently used. The completed instrument is seen as a useful unit of scientific progress in its own right. (UK)

Flares: solar and stellar. Rutherford Appleton Laboratory workshop on astronomy and astrophysics, Abingdon, 19-21 May 1986

International Nuclear Information System (INIS)

Gondhalekar, P.M.

1986-05-01

The paper concerns solar and stellar flare phenomena reported at the Rutherford Appleton Laboratory Workshop on Astronomy and Astrophysics, May 1986. Eleven papers were presented at the Workshop on: the solar-stellar connection, observational evidence for solar and stellar flares, and flare models; and all are indexed separately. (UK)

Cyclotrons at the Institute of Physical and Chemical Research

International Nuclear Information System (INIS)

Imamura, Masashi.

1989-01-01

In this article the destruction by American forces, during World War II, of the Japanese cyclotrons and the subsequent construction of new cyclotrons at the Institute of Physical and Chemical Research, Japan is described. Their use for biological and medical radiation chemistry studies is summarized. (UK)

Dynamic effects on cyclotron scattering in pulsar accretion columns

International Nuclear Information System (INIS)

Brainerd, J.J.; Meszaros, P.

1991-01-01

A resonant scattering model for photon reprocessing in a pulsar accretion column is presented. The accretion column is optically thin to Thomson scattering and optically thick to resonant scattering at the cyclotron frequency. Radiation from the neutron star surface propagates freely through the column until the photon energy equals the local cyclotron frequency, at which point the radiation is scattered, much of it back toward the star. The radiation pressure in this regime is insufficient to stop the infall. Some of the scattered radiation heats the stellar surface around the base of the column, which adds a softer component to the spectrum. The partial blocking by the accretion column of X-rays from the surface produces a fan beam emission pattern. X-rays above the surface cyclotron frequency freely escape and are characterized by a pencil beam. Gravitational light bending produces a pencil beam pattern of column-scattered radiation in the antipodal direction, resulting in a strongly angle-dependent cyclotron feature. 31 refs

Uniqueness for the inverse backscattering problem for angularly controlled potentials

International Nuclear Information System (INIS)

Rakesh; Uhlmann, Gunther

2014-01-01

We consider the problem of recovering a smooth, compactly supported potential on R 3 from its backscattering data. We show that if two such potentials have the same backscattering data and the difference of the two potentials has controlled angular derivatives, then the two potentials are identical. In particular, if two potentials differ by a finite linear combination of spherical harmonics with radial coefficients and have the same backscattering data then the two potentials are identical. (paper)

Ion cyclotron resonance heating

International Nuclear Information System (INIS)

Tajima, T.

1982-01-01

Ion cyclotron resonance heating of plasmas in tokamak and EBT configurations has been studied using 1-2/2 and 2-1/2 dimensional fully self-consistent electromagnetic particle codes. We have tested two major antenna configurations; we have also compared heating efficiencies for one and two ion species plasmas. We model a tokamak plasma with a uniform poloidal field and 1/R toroidal field on a particular q surface. Ion cyclotron waves are excited on the low field side by antennas parallel either to the poloidal direction or to the toroidal direction with different phase velocities. In 2D, minority ion heating (vsub(perpendicular)) and electron heating (vsub(parallel),vsub(perpendicular)) are observed. The exponential electron heating seems due to the decay instability. The minority heating is consistent with mode conversion of fast Alfven waves and heating by electrostatic ion cyclotron modes. Minority heating is stronger with a poloidal antenna. The strong electron heating is accompanied by toroidal current generation. In 1D, no thermal instability was observed and only strong minority heating resulted. For an EBT plasma we model it by a multiple mirror. We have tested heating efficiency with various minority concentrations, temperatures, mirror ratios, and phase velocities. In this geometry we have beach or inverse beach heating associated with the mode conversion layer perpendicular to the toroidal field. No appreciable electron heating is observed. Heating of ions is linear in time. For both tokamak and EBT slight majority heating above the collisional rate is observed due to the second harmonic heating. (author)

Intelligent CAE system of CYCLONE type cyclotron main magnet and its applications

International Nuclear Information System (INIS)

Zhang Tianjue; Chen Yong; Fan Mingwu

1993-01-01

The main magnet that features the cyclotron is the most important part in a cyclotron construction. Though there are many codes devoted to solving magnetic field computation problems, the results depend on the user's skill and experience very much. To help a cyclotron magnet designer get acceptable results, an intelligent CAE system for CYCLONE type cyclotron magnet design and machining has been developed. Reasonable good results could be got even the designer with the help from an expert knowledge library installed in the program

Passive cyclotron current drive for fusion plasmas

International Nuclear Information System (INIS)

Kernbichler, W.

1995-01-01

The creation of toroidal current using cyclotron radiation in a passive way is, together with the well known bootstrap current, an interesting method for stationary current drive in high-temperature fusion reactors. Here, instead of externally applied RF-waves, fish-scale like structures at the first wall help to create enough asymmetry in the self generated cyclotron radiation intensity to drive a current within the plasma. The problem of computing passive cyclotron current drive consists of actually two linked problems, which are the computation of the electron equilibrium under the presence of self-generated radiation, and the computation of the photon equilibrium in a bounded system with a distorted electron distribution. This system of integro-differential equations cannot be solved directly in an efficient way. Therefore a linearization procedure was developed to decouple both sets of equations, finally linked through a generalized local current drive efficiency. The problem of the exact accounting for the wall profile effects was reduced to the solution of a Fredholm-type integral equation of the 2 nd -kind. Based on all this an extensive computer code was developed to compute the passively driven current as well as radiation losses, radiation transport and overall efficiencies. The results therefrom give an interesting and very detailed insight into the problems related to passive cyclotron current drive

On the coupling of cyclotron motion to ion internal degrees of freedom

International Nuclear Information System (INIS)

Dunbar, R.C.

1979-01-01

A possibility of significant coupling between gas-phase ion cyclotron motion and two internal angular momentum terms is explored. The first case, coupling with ion spin, is treated via the relativistic Hamiltonian, and found to produce only relativistic perturbations which are entirely negligible. The second case, coupling with ion rotation, is developed via its equivalence to a Stark effect. Small shifts in the cyclotron resonances frequency , ωsub(c) and the appearance of a weak cyclotron resonance at 2ωsub(c) are predicted, but these effects are negligible in general. If the cyclotron frequency is near an ion rotational transition, however, a shift of 10 -5 in cyclotron frequency may be observed, and could provide a means of investigating low-frequency rotational transitions of ions. (Auth.)

Quantitative Analysis of Venus Radar Backscatter Data in ArcGIS

Science.gov (United States)

Long, S. M.; Grosfils, E. B.

2005-01-01

Ongoing mapping of the Ganiki Planitia (V14) quadrangle of Venus and definition of material units has involved an integrated but qualitative analysis of Magellan radar backscatter images and topography using standard geomorphological mapping techniques. However, such analyses do not take full advantage of the quantitative information contained within the images. Analysis of the backscatter coefficient allows a much more rigorous statistical comparison between mapped units, permitting first order selfsimilarity tests of geographically separated materials assigned identical geomorphological labels. Such analyses cannot be performed directly on pixel (DN) values from Magellan backscatter images, because the pixels are scaled to the Muhleman law for radar echoes on Venus and are not corrected for latitudinal variations in incidence angle. Therefore, DN values must be converted based on pixel latitude back to their backscatter coefficient values before accurate statistical analysis can occur. Here we present a method for performing the conversions and analysis of Magellan backscatter data using commonly available ArcGIS software and illustrate the advantages of the process for geological mapping.

Evaluation of the photon monitor backscatter in medical electron accelerators

International Nuclear Information System (INIS)

Zrenner, M.; Krieger, H.

1999-01-01

Background: Modern linear accelerators permit the use of irregular fields due to their flexible collimator systems with separately movable jaws or multileaf collimators. When using such irregular fields in the clinical practice output factors have to be corrected for enhanced backscatter to the dose monitor as compared with the conventional block shieldings. Methods: A method is presented to detect the monitor backscatter contributions to the output factor for irregular field settings. Results: The monitor backscatter factors have been measured using a telescopic device for 2 different treatment head geometries (Varian Clinac 2100C/D, General Electric Saturne 15) and for 3 photon radiation qualities (nominal energies X6, X18, X12). A method is introduced to calculate the monitor backscatter for arbitrary irregular treatment fields from the experimental data for square or rectangular fields. Conclusions: Besides the corrections for changes in phantom scatter and changes in the aperture, corrections for monitor backscatter have to be taken into account in many clinical cases. They can contribute up to more than 10% compared with the monitor values for free regular fields. (orig.) [de

ECR heavy-ion source for the LBL 88-inch cyclotron

International Nuclear Information System (INIS)

Clark, D.J.; Kalnins, J.G.; Lyneis, C.M.

1983-03-01

An Electron Cyclotron Resonance (ECR) heavy-ion source is under construction at the LBL 88-Inch Cyclotron. This source will produce very-high-charge-state heavy ions, such as 0 8 + and Ar 12 + , which will increase cyclotron energies by a factor of 2-4, up to A = 80. It is a two-stage source using room-temperature coils, a permanent-magnet sextupole, and a 6-9 GHz microwave system. Design features include adjustable first-to-second-stage plasma coupling, a variable second-stage mirror ratio, high-conductance radial pumping of the second stage, and a beam-diagnostic system. A remotely movable extraction electrode will optimize extraction efficiency. The project includes construction of a transport line and improvements to the cyclotron axial-injection system. The construction period is expected to be two years

Review of Cyclotrons for the Production of Radioactive Isotopes for Medical and Industrial Applications

Science.gov (United States)

Schmor, Paul

2011-02-01

Radioactive isotopes are used in a wide range of medical, biological, environmental and industrial applications. Cyclotrons are the primary tool for producing the shorter-lived, proton-rich radioisotopes currently used in a variety of medical applications. Although the primary use of the cyclotron-produced short-lived radioisotopes is in PET/CT (positron emission tomography/computed tomography) and SPECT (single photon emission computed tomography) diagnostic medical procedures, cyclotrons are also producing longer-lived isotopes for therapeutic procedures as well as for other industrial and applied science applications. Commercial suppliers of cyclotrons are responding by providing a range of cyclotrons in the energy range of 3-70MeV for the differing needs of the various applications. These cyclotrons generally have multiple beams servicing multiple targets. This review article presents some of the applications of the radioisotopes and provides a comparison of some of the capabilities of the various current cyclotrons. The use of nuclear medicine and the number of cyclotrons supplying the needed isotopes are increasing. It is expected that there will soon be a new generation of small "tabletop" cyclotrons providing patient doses on demand.

Study of axial injection of polarized protons into the grenoble cyclotron; Contribution a l'etude de l'injection axiale pour protons polarises sur le cyclotron de Grenoble

Energy Technology Data Exchange (ETDEWEB)

Pabot, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

By injecting ions axially into a cyclotron, it is possible to accelerate particles (polarized particles, heavy ions, etc...) obtainable only with difficulty when an internal ion source is used. In this work, after justifying the choice of an axial injection device equipped with a 'pseudo-cylindrical' deflector for the Grenoble cyclotron, we study theoretically the principle of such a detector, the choice of its parameters, and the effect of this choice on the conditions of acceleration of the beam by the cyclotron. From the experimental point of view, this report describes two operations which made it possible to check that the chosen injection device operated satisfactorily, qualitatively initially (electron model), then quantitatively (proton model). In conclusion, we believe that the Grenoble cyclotron thus equipped will be able to provide a relatively dense beam of polarized protons. (author) [French] L'injection axiale d'ions dans un cyclotron permet d'accelerer des particules (particules polarisees, ions lourds... ) difficiles a obtenir avec une source interne d'ions. Dans ce travail, apres avoir justifie le choix d'un dispositif d'injection axiale equipe d'un deflecteur 'pseudo-cylindrique' pour le cyclotron de Grenoble, nous avons etudie, du point de vue theorique, le principe d'un tel deflecteur, le choix de ses parametres, et l'incidence de ce choix sur les conditions d'acceleration du faisceau par le cyclotron. Du point de vue experimental, ce rapport decrit deux manipulations qui ont permis de verifier le bon fonctionnement du dispositif d'injection retenu, qualitativement d'abord (modele a electrons), quantitativement ensuite (maquette a protons). En conclusion, nous estimons que le cyclotron de Grenoble ainsi equipe, peut fournir un faisceau relativement intense de protons polarises. (auteur)

Operation of the Karlsruhe Isochronous Cyclotron in 1976

International Nuclear Information System (INIS)

Schulz, F.; Schweickert, H.

1977-08-01

The operation of the Karlsruhe Isochronous Cyclotron in 1976 is briefly surveyed. The status and the results of the following technical developments are briefly described: 1) Computer aided cyclotron operation; 2) New correction coils for the cyclotron; 3) Non-intercepting measurement of the extraction rate; 4) Lambshift source for polarized deuterons; 5) Improvements of the 6 Li 3+ -Penning ion source; 6) New beam line to an irradiation room for machine parts; 7) Nova 2 computer system for nuclear physics experiments; 8) Routine production of Iodine-123 for nuclear medicine. - In the annual report 1975 we have included a section consisting of a series of brief reports on applied research in progress. This year we give a compilation of the current basic nuclear physics work at our cyclotron. The short papers prepared by the experimental groups are arranged according to the following topics: 1) Experiments using the 156 MeV 6 Li 3+ -beam; 2) Experiments using the 52 MeV polarized deuteron beam; 3) Further nuclear reactions; 4) Nuclear spectroscopy; 5) Measurements of nuclear magnetic moments; 6) Measurements with the neutron time-of-flight spectrometer. (orig.) [de

Optical Backscattering Measured by Airborne Lidar and Underwater Glider

Directory of Open Access Journals (Sweden)

James H. Churnside

2017-04-01

Full Text Available The optical backscattering from particles in the ocean is an important quantity that has been measured by remote sensing techniques and in situ instruments. In this paper, we compare estimates of this quantity from airborne lidar with those from an in situ instrument on an underwater glider. Both of these technologies allow much denser sampling of backscatter profiles than traditional ship surveys. We found a moderate correlation (R = 0.28, p < 10−5, with differences that are partially explained by spatial and temporal sampling mismatches, variability in particle composition, and lidar retrieval errors. The data suggest that there are two different regimes with different scattering properties. For backscattering coefficients below about 0.001 m−1, the lidar values were generally greater than the glider values. For larger values, the lidar was generally lower than the glider. Overall, the results are promising and suggest that airborne lidar and gliders provide comparable and complementary information on optical particulate backscattering.

Directory of cyclotrons used for radionuclide production in Member States [2006 update

International Nuclear Information System (INIS)

2006-10-01

The present directory of cyclotron facilities used for the production of radionuclides in Member States is an update of the one compiled by the International Atomic Energy Agency (IAEA) in late 2001 and published in 2002. This directory was prepared through information collected by questionnaires that the IAEA sent to known institutions operating cyclotrons for radionuclide production. Technical as well as administrative data supplied to the IAEA as of November 2005 were taken into account. The directory is considered to include most of the cyclotrons of the world that are used at least partially for radionuclide production. There are 262 entries for cyclotrons operating in 39 Member States of the IAEA. This is an increase of 7% over the 246 reported in the 2002 cyclotron directory. This can be compared to the 350 or so cyclotrons believed to be presently operating in the world, which are involved in some aspects of radionuclide production. The increase has been in the number of cyclotrons in developed countries, but even more so in the developing countries. The increase in number during the last four years was driven by several factors, i.e. advent of advances in medical imaging, introduction of compact, user friendly medical cyclotron, and a recent decision that costs for 15 O-oxygen position emission tomography (PET) studies in Japan and 18 F-FDG PET studies in Germany and the United States of America are eligible for reimbursement by government or health insurance companies. There is no doubt that the fastest growing segment of the market is in the commercial distribution of FDG to local hospitals. The IAEA is promoting cyclotron technology as applied to nuclear medicine. Requests for cyclotron technology is steadily increasing; many developing Member States are interested in this technology. There is need to stimulate, build and maintain consulting capability in interested developing Member States. There are good reasons to believe that the number of cyclotron

Next customers to cyclotron center meanwhile are not entered

International Nuclear Information System (INIS)

Bato, R.; Zackova, K.

2004-01-01

In this paper the financial aspects of construction of the Cyclotron Centre of the Slovak Republic (CC SR) are analysed. This building represents the problems of exploitation of commodity deblocation of Russian Federation debt to Slovakia. The estimated expenses have risen from original planned 2 billion Slovak crowns to 6 billion Slovak crowns. Devices which should be part of centre - a cyclotron used for radiopharmaceuticals production for oncological purposes and a big cyclotron for industrial purposes, a centre of positron emissive tomography (PET), a laboratory of nano-technologies, a source of heavy ions - they indicates that the oncological institutes, departments of health service, of education, of economy, of defence, of environment, also Nuclear Regulatory Authority of Slovak Republic and Slovak Academy of Sciences should become the customers principally. Around 2.2 billion of Slovak crowns from deblocation have been spent for a construction of Cyclotron Centre of SR yet. The national budget has contributed by 95 million Slovak crowns; 90.5 million USD will be obtained from deblocation of Russian debt yet. IAEA has supported this centre by grant of almost 800 thousand USD. Budget of Cyclotron Centre of SR is still rising also because of rising of VAT from 10 percent to 19 percent. VAT will be paid also for goods imported within the framework of deblocation after integration of Slovak Republic to European Union; besides also 10 percent duty is paid. Project of CC SR has not passed the state expert opinion. Agreement for construction of Cyclotron Centre of SR was issued by State Health Institute of Bratislava, therefore it was confirmed also by the main hygienist of Slovak Republic

Thin Film Materials and Devices for Resistive Temperature Sensing Applications

Science.gov (United States)

2015-05-21

Rutherford backscattering spectroscopy (RBS), Raman spectroscopy, scanning electron microscopy (SEM), TEM, and atomic force microscopy (AFM) did...composition and structure by real time spectroscopic ellipsometry," Physica Status Solidi A, vol. 205, pp. 892-895, 2008. [92] H. Fujiwara, J. Koh , P. I

Mass measurements with the CIME cyclotron at GANIL

International Nuclear Information System (INIS)

Hornillos, M B Gomez; Chartier, M; Mittig, W; Blank, B; Chautard, F; Demonchy, C E; Gillibert, A; Jacquot, B; Jurado, B; Lecesne, N; Lepine-Szily, A; Orr, N A; Roussel-Chomaz, P; Savajols, H; Villari, A C C

2005-01-01

A new direct technique using the CIME cyclotron as a high-resolution mass spectrometer is being developed in order to measure the masses of exotic nuclei. Tests have been performed to check the feasibility of the method with a mixed beam of stable ions extracted from the SPIRAL ion source and injected into the CIME cyclotron. Preliminary results obtained with this new technique are presented and discussed

Improving cancer treatment with cyclotron produced radionuclides. Progress report

Energy Technology Data Exchange (ETDEWEB)

Larson, S.M.; Finn, R.D.

1993-11-01

This report describes our continuing long term goal of promoting nuclear medicine applications by improving the scientific basis for tumor diagnosis, treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The program includes 3 interactive components: Radiochemistry/Cyclotron; Pharmacology; and Immunology. An essential strategy is as follows: novel radionuclides and radiotracers developed in the Radiochemistry/Cyclotron section will be employed in the Pharmacology and Immunology sections during the next year. The development of novel radionuclides and tracers is of course useful in and of itself, but their utility is greatly enhanced by the interaction with the immunology and pharmacology components of the program.

Study of multibeam techniques for bathymetry and seabottom backscatter applications

Digital Repository Service at National Institute of Oceanography (India)

Nair, R.R.; Chakraborty, B.

Indian ocean is presented using Hydrosweep-multibeam installed onboard ORV Sagarkanya. A seabottom classification model is proposed which can be applied for multibeam backscatter data. Certain aspects of the multibeam backscatter signal data processing...

Relativistic nonlinear waves of cyclotron in electron and electron-ion plasmas

International Nuclear Information System (INIS)

Bruno, R.

1981-12-01

Dispersion relations for electron-cyclotron and ion-cyclotron waves are examined in two models of plasmas, the first propagating in fluent electronic plasmas (''streaming'') as well as in fluent electron-ionic plasmas, and the last in fluent electron-ionic plasmas. The identification of the propagation modes is realized with the aid of a special technique of polinomial expantion of the dispersion relation in the limit of large frequencies and short wavelenghts. The analisys so developed on these dispersion relations for fluent plasmas show that: (i) the wave amplitudes are frequency dependent; (ii) the ''resonances'' frequencies of the respective estationary plasmas must be re-examined with the relations between wave amplitudes and the propagation frequencies near these frequencies; (iii) the electric field amplitudes for the non-linear waves of electron-cyclotron and ion-cyclotron go to zero in the limits of the respective cyclotron frequencies in both fluent plasma models. (M.W.O.) [pt

Medical isotope production experience at the V.G. Khlopin Radium Institute cyclotron

International Nuclear Information System (INIS)

Solin, L.M.

2000-01-01

Radium Institute cyclotron MGC-20 is used since 1990. There are four cyclotrons of such type in Russia and four abroad: in Finland, in Hungary, in North Korea and in Egypt. The Radium institute cyclotron was used in different fields, such as radioisotope production, nuclear physics, physics and engineering. For ten years some improvements of the Radium Institute cyclotron operation have been made. Those are: creation of the automatic control system based on IBM PC, development of a new power supply for the ion source, creation of the deflector electronic protection from discharges, change of the main elements of the cyclotron with high induced radioactivity. Moreover we investigated the possibility of the negative ions acceleration at the MGC-20 cyclotron without ion source exchange. The maximum value of the proton beam current reached was about 30 μA for 10 MeV H - beam energy. To extract the proton beam from the cyclotron after the stripping foil we made an additional output beam line. It was used for determination of the horizontal and vertical emittance. A special device was constructed and used for measurements of emittance. The latter amounted 30 π mm mrad for horizontal direction and 16 π mm mrad for vertical direction

Transparency of Magnetized Plasma at Cyclotron Frequency

International Nuclear Information System (INIS)

G. Shvets; J.S. Wurtele

2002-03-01

Electromagnetic radiation is strongly absorbed by a magnetized plasma if the radiation frequency equals the cyclotron frequency of plasma electrons. It is demonstrated that absorption can be completely canceled in the presence of a magnetostatic field of an undulator or a second radiation beam, resulting in plasma transparency at the cyclotron frequency. This effect is reminiscent of the electromagnetically induced transparency (EIT) of the three-level atomic systems, except that it occurs in a completely classical plasma. Unlike the atomic systems, where all the excited levels required for EIT exist in each atom, this classical EIT requires the excitation of the nonlocal plasma oscillation. The complexity of the plasma system results in an index of refraction at the cyclotron frequency that differs from unity. Lagrangian description was used to elucidate the physics and enable numerical simulation of the plasma transparency and control of group and phase velocity. This control naturally leads to applications for electromagnetic pulse compression in the plasma and electron/ion acceleration

Important radiation protection aspects of the operation of a commercial medical cyclotron

International Nuclear Information System (INIS)

Mukherjee, B.

1997-01-01

Since July 1991 the Radiopharmaceutical Division of the Australian Nuclear Science and Technology Organisation (ANSTO) operates a 30 MeV H'- ion Medical Cyclotron (Model; CYCLONE 30, Manufacturer: Ion Beam Applications, Louvain La Neuve, Belgium). During routine isotope production operations at the cyclotron a thick copper substrate plate electroplated with thin layer of selected enriched target material are bombarded with 30 MeV proton beam current up to 450 μA. The nuclear reaction of protons with the copper atoms result in the reduction of prompt evaporation neutrons with a peak energy of ∼ 1.8 MeV. These evaporation neutrons slow down via multiple collisions with the concrete shielding walls of the target cave, bounce back to the,interior space of the cave activating the cyclotron parts, beam tube components and other utilities installed in the irradiation cave. After the completion of 60 hour isotope production run, gamma dose equivalent rates of ∼10 5 μSvh -1 were measured at contact with the target irradiation stations and beam collimators. Evidently, these gamma rays emitted from the activated cyclotron components impose crucial radiation exposure hazard problems for the cyclotron maintenance technicians. Experiments had been carried out in order to identify the specific pathways of cyclotron component activation and to assess the probable personnel radiation exposure during handling of the activated cyclotron parts. The cool-down (radioactive decay) of the activated cyclotron components was estimated experimentally at different target bombardment conditions using the wall mounted gamma area monitors interfaced to the Health Physics Data Acquisition System. The gamma dose equivalent rates at contact with various locations of interest at the target irradiation station and at the typical work areas of the maintenance personnel were carefully recorded with a radiation (gamma) survey instrument during the three years operation period of the cyclotron. A

HF coherent backscatter in the ionosphere: In situ measurements of SuperDARN backscatter with e-POP RRI

Science.gov (United States)

Perry, G. W.; James, H. G.; Hussey, G. C.; Howarth, A. D.; Yau, A. W.

2017-12-01

We report in situ polarimetry measurements of HF scattering obtained by the Enhanced Polar Outflow Probe (e-POP) Radio Receiver Instrument (RRI) during a coherent backscatter scattering event detected by the Saskatoon Super Dual Auroral Radar Network (SuperDARN). On April 1, 2015, e-POP conducted a 4 minute coordinated experiment with SuperDARN Saskatoon, starting at 3:38:44 UT (21:38:44 LT). Throughout the experiment, SuperDARN was transmitting at 17.5 MHz and e-POP's ground track moved in a northeastward direction, along SuperDARN's field-of-view, increasing in altitude from 331 to 352 km. RRI was tuned to 17.505 MHz, and recorded nearly 12,000 SuperDARN radar pulses during the experiment. In the first half of the experiment, radar pulses recorded by RRI were "well behaved": they retained their transmitted amplitude envelope, and their pulse-to-pulse polarization characteristics were coherent - Faraday rotation was easily measured. During the second half of the experiment the pulses showed clear signs of scattering: their amplitude envelopes became degraded and dispersed, and their pulse-to-pulse polarization characteristics became incoherent - Faraday rotation was difficult to quantify. While these pulses were being received by RRI, SuperDARN Saskatoon detected a latitudinal band of coherent backscatter at e-POP's location, indicating that the scattered pulses measured by RRI may be a signature of HF backscatter. In this presentation, we will outline the polarimetric details of the scattered pulses, and provide an analytic interpretation of RRI's measurements to give new insight into the nature of HF coherent backscatter mechanism taking place in the terrestrial ionosphere.

Light backscattering efficiency and related properties of some phytoplankters

Science.gov (United States)

Ahn, Yu-Hwan; Bricaud, Annick; Morel, André

1992-11-01

By using a set-up that combines an integrating sphere with a spectroradiometer LI-1800 UW, the backscattering properties of nine different phytoplankters grown in culture have been determined experimentally for the wavelengths domain ν = 400 up to 850 nm. Simultaneously, the absorption and attenuation properties, as well as the size distribution function, have been measured. This set of measurements allowed the spectral values of refractive index, and subsequently the volume scattering functions (VSF) of the cells, to be derived, by operating a scattering model previously developed for spherical and homogeneous cells. The backscattering properties, measured within a restricted angular domain (approximately between 132 and 174°), have been compared to theoretical predictions. Although there appear some discrepancies between experimental and predicted values (probably due to experimental errors as well as deviations of actual cells from computational hypotheses), the overall agreement is good; in particular the observed interspecific variations of backscattering values, as well as the backscattering spectral variation typical of each species, are well accounted for by theory. Using the computed VSF, the measured backscattering properties can be converted (assuming spherical and homogeneous cells) into efficiency factors for backscattering ( overlineQbb) . Thhe spectral behavior of overlineQbb appears to be radically different from that for total scattering overlineQb. For small cells, overlineQ (λ) is practically constant over the spectrum, whereas overlineQb(λ) varies approximately according to a power law (λ -2). As the cell size increases, overlineQbb conversely, becomes increasingly featured, whilst overlineQb becomes spectrally flat. The chlorophyll-specific backscattering coefficients ( b b∗ appear highly variable and span nearly two orders of magnitude. The chlorophyll-specific absorption and scattering coefficients, a ∗ and b ∗, are mainly ruled by

Potential of cyclotron based accelerators for energy production and transmutation

Energy Technology Data Exchange (ETDEWEB)

Stammbach, T.; Adam, S.; Fitze, H.R. [Paul Scherrer Institute, Villigen (Switzerland)] [and others

1995-10-01

PSI operates a 590 MeV-cyclotron facility for high intensity proton beams for the production of intense beams of pions and muons. The facility, commissioned in 1974, has been partially upgraded and is now operated routinely at a beam current of 1 mA, which corresponds to a beam power of 0.6 MW. At this current, the beam losses in the cyclotron are about 0.02%. By the end of 1995 the authors expect to have 1.5 mA of protons. Extensive theoretical investigations on beam current limitations in isochronous cyclotrons were undertaken. They show that the longitudinal space charge effects dominate. Based on their experience the authors present a preliminary design of a cyclotron scheme that could produce a 10 MW beam as a driver for an {open_quotes}energy amplifier{close_quotes} as proposed by C. Rubbia and his collaborators. The expected efficiency for the conversion of AC into beam power would be about 50% (for the RF-systems only). The beam losses in the cyclotron are expected to be a few {mu}A, leading to a tolerable activation level.

Development and application of intelligent CAE system for cyclotron main magnet

International Nuclear Information System (INIS)

Zhang Tianjue; Chen Yong; Fan Mingwu

1993-01-01

The main magnet that represents the feature of the cyclotron is the most important part in a cyclotron construction. Though there are many codes devoted to solve magnetic field computation problems, the results from them are depended on user's skill and experience very much. To help cyclotron magnet designer get acceptable result an intelligent CAE system for cyclotron main magnet design and machining has been developed. A reasonable good results in design could be get even the designer is a beginner with the help from an expert knowledge library installed in the program. The codes include following functions: 1. Intelligent CAD; 2. 2D and 3D magnetic field computation; 3. Beam dynamics analysis; 4. CAM for main magnet

Cyclotron-Resonance-Maser Arrays

International Nuclear Information System (INIS)

Kesar, A.; Lei, L.; Dikhtyar, V.; Korol, M.; Jerby, E.

1999-01-01

The cyclotron-resonance-maser (CRM) array [1] is a radiation source which consists of CRM elements coupled together under a common magnetic field. Each CRM-element employs a low-energy electron-beam which performs a cyclotron interaction with the local electromagnetic wave. These waves can be coupled together among the CRM elements, hence the interaction is coherently synchronized in the entire array. The implementation of the CRM-array approach may alleviate several technological difficulties which impede the development of single-beam gyro-devices. Furthermore, it proposes new features, such as the phased-array antenna incorporated in the CRM-array itself. The CRM-array studies may lead to the development of compact, high-power radiation sources operating at low-voltages. This paper introduces new conceptual schemes of CRM-arrays, and presents the progress in related theoretical and experimental studies in our laboratory. These include a multi-mode analysis of a CRM-array, and a first operation of this device with five carbon-fiber cathodes

A conceptual design of high-temperature superconducting isochronous cyclotron magnet

International Nuclear Information System (INIS)

Jiao, F.; Tang, Y.; Li, J.; Ren, L.; Shi, J.

2011-01-01

A design of High-temperature superconducting (HTS) isochronous cyclotron magnet is proposed. The maximum magnetic field of cyclotron main magnet reaches 3 T. Laying the HTS coil aboard the magnetic pole will raise the availability of the magnetic Field. Super-iron structure can provide a high uniformity and high gradient magnetic field. Super-iron structure can raise the availability of the HTS materials. Along with the development of High-temperature superconducting (HTS) materials, the technology of HTS magnet is becoming increasingly important in the Cyclotron, which catches growing numbers of scholars' attentions. Based on the analysis of the problems met in the process of marrying superconducting materials with ferromagnetic materials, this article proposes a design of HTS isochronous cyclotron magnet. The process of optimization of magnet and the methods of realizing target parameters are introduced after taking finite element software as analyzing tools.

Magnetic field optimisation and orbit calculation for VEC superconducting cyclotron

International Nuclear Information System (INIS)

Debnath, J.; Dey, M.K.; Mallik, C.; Bhandari, R.K.

2003-01-01

At VECC, Kolkata preparations are underway to measure the magnetic field of the cyclotron. Also once the superconducting cyclotron is assembled prediction of beam related parameters will be a very important exercise to carry out. Considering this the beam behaviour in the cyclotron will be crucial to achieve these goals. The present paper deals with the efforts in this direction and using a test beam of He 1+ 20 MeV/n the trim coil currents, the tune variation and the (r,Pr) behaviour of the central trajectory

On 'conflict of conservation laws in cyclotron radiation'

International Nuclear Information System (INIS)

White, S.M.; Parle, A.J.

1985-01-01

The authors reconsider the apparent conflict of conservation laws in cyclotron radiation, and show that earlier workers in this field did not correctly include the effects of radiation reaction in their calculations. When a 'recoil' term, calculated using relativistic quantum theory, is included in the angular momentum of the particle the conflict disappears. It is found that the guiding centre of the particle drifts outwards during cyclotron radiation. (author)

Channel of Axial Injection of DC-60 Cyclotron

CERN Document Server

Gikal, B N; Bogomolov, S L; Borisenko, A N; Borisov, O N; Gulbekyan, G G; Ivanenko, I A; Kalagin, I V; Kazacha, V I; Kazarinov, N Yu; Khabarov, M V; Lysukhin, S N; Melnikov, V N; Paschenko, S V; Tikhomirov, A V

2006-01-01

The design study and realization of the axial injection beam line of DC-60 cyclotron constructed at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research are given. The channel allows one to transport and to inject into the cyclotron ions with mass-to-charge ratio $A/Z$ being within interval A/Z=6-12 and kinetic energy up to 17 $Z/A$ keV/m.u.

Goodbye Synchro-Cyclotron

Energy Technology Data Exchange (ETDEWEB)

Anon.

1990-12-15

On 17 December, after having seen many other physics machines come and go during its 33-year career, CERN's 600 MeV SynchroCyclotron (SC) is being shut down. Judged simply by its length (to say nothing of its quality), the research career of this machine testifies to the wisdom and imagination of the CERN pioneers who proposed it in the early 1950s.

Goodbye Synchro-Cyclotron

International Nuclear Information System (INIS)

Anon.

1990-01-01

On 17 December, after having seen many other physics machines come and go during its 33-year career, CERN's 600 MeV SynchroCyclotron (SC) is being shut down. Judged simply by its length (to say nothing of its quality), the research career of this machine testifies to the wisdom and imagination of the CERN pioneers who proposed it in the early 1950s

Relating multifrequency radar backscattering to forest biomass: Modeling and AIRSAR measurement

Science.gov (United States)

Sun, Guo-Qing; Ranson, K. Jon

1992-01-01

During the last several years, significant efforts in microwave remote sensing were devoted to relating forest parameters to radar backscattering coefficients. These and other studies showed that in most cases, the longer wavelength (i.e. P band) and cross-polarization (HV) backscattering had higher sensitivity and better correlation to forest biomass. This research examines this relationship in a northern forest area through both backscatter modeling and synthetic aperture radar (SAR) data analysis. The field measurements were used to estimate stand biomass from forest weight tables. The backscatter model described by Sun et al. was modified to simulate the backscattering coefficients with respect to stand biomass. The average number of trees per square meter or radar resolution cell, and the average tree height or diameter breast height (dbh) in the forest stand are the driving parameters of the model. The rest of the soil surface, orientation, and size distributions of leaves and branches, remain unchanged in the simulations.

Acoustic backscatter at a Red Sea whale shark aggregation site

KAUST Repository

Hozumi, Aya; Kaartvedt, Stein; Rø stad, Anders; Berumen, Michael L.; Cochran, Jesse E.M.; Jones, Burton

2018-01-01

An aggregation of sexually immature whale sharks occurs at a coastal submerged reef near the Saudi Arabian Red Sea coast each spring. We tested the hypothesis that these megaplanktivores become attracted to a prey biomass peak coinciding with their aggregation. Acoustic backscatter of the water column at 120 kHz and 333 kHz –a proxy for potential prey biomass –was continuously measured spanning the period prior to, during, and subsequent to the seasonal whale shark aggregations. No peak in acoustic backscatter was observed at the time of the aggregation. However, we observed a decrease in acoustic backscatter in the last days of deployment, which coincided the trailing end of whale shark season. Organisms forming the main scattering layer performed inverse diel vertical migration, with backscatter peaking at mid-depths during the day and in the deeper half of the water column at night. Target strength analyses suggested the backscatter was likely composed of fish larvae. Subsurface foraging behavior of the whale sharks within this aggregation has not been described, yet this study does not support the hypothesis that seasonal peaks in local whale shark abundance correspond to similar peaks in prey availability.

Acoustic backscatter at a Red Sea whale shark aggregation site

KAUST Repository

Hozumi, Aya

2018-03-28

An aggregation of sexually immature whale sharks occurs at a coastal submerged reef near the Saudi Arabian Red Sea coast each spring. We tested the hypothesis that these megaplanktivores become attracted to a prey biomass peak coinciding with their aggregation. Acoustic backscatter of the water column at 120 kHz and 333 kHz –a proxy for potential prey biomass –was continuously measured spanning the period prior to, during, and subsequent to the seasonal whale shark aggregations. No peak in acoustic backscatter was observed at the time of the aggregation. However, we observed a decrease in acoustic backscatter in the last days of deployment, which coincided the trailing end of whale shark season. Organisms forming the main scattering layer performed inverse diel vertical migration, with backscatter peaking at mid-depths during the day and in the deeper half of the water column at night. Target strength analyses suggested the backscatter was likely composed of fish larvae. Subsurface foraging behavior of the whale sharks within this aggregation has not been described, yet this study does not support the hypothesis that seasonal peaks in local whale shark abundance correspond to similar peaks in prey availability.

40. anniversary of cyclotron of Institute of Nuclear Physics, Tashkent

International Nuclear Information System (INIS)

Umerov, R.A.; Uzakov, J.M.; Gulamov, I.R.

2004-01-01

Full text: The Cyclotron U-150-II of Institute of Nuclear Physics was projected in middle of the last century for nuclear-physical researches in a scientific research institute of electro physical equipment in Leningrad. The Cyclotron can accelerate positive ions with beam energy of the protons 18 MeV, deuterons 20 MeV, alpha particles 40 MeV. Intensity of a beam a little some microampere. The building of a Cyclotron represents an impressive three-floor construction in volume of 2000 m 3 . The capital equipment, the high-frequency generator, sources of power supplies, vacuum pumps and other technological units are placed on the first and socle floors of a building. The second and third floors served for accommodation of scientific laboratories. A building of a Cyclotron has three experimental halls, where it was possible to carry out physical researches. They have divided from each other, and the main thing from the accelerator, concrete walls with the purpose of reduction of the big radiating background at the working accelerator, preventing realization of experiments. It provided also biological protection of the on duty personnel. The first some years of operation of the Cyclotron have revealed a line of lacks of this machine. For example, for change of energy of a beam of a Cyclotron it took 2-3 weeks. Also, for transition of acceleration of one particles to others it take same time. Time parameters of a beam were unstable. In 1968 reconstruction of the Cyclotron has been started that has allowed to bring in basic changes to parameters U-150-II. The time took on change of an operating mode of a Cyclotron was sharply reduced, and it was possible to reduce it till 10-20 hours, to improve the energy and time resolution of a beam many times over, to reduce angular straggling of particles in a beam. And, all this enormous amount of works was spent by forces of institute. In 70 th years the big development was received with works on radiating stability of materials

Intelligent CAE system of CYCLONE type cyclotron main magnet and its applications

International Nuclear Information System (INIS)

Zhang Tianjue; Chen Yong; Fan Mingwu

1992-07-01

The main magnet that represents the feature of the cyclotron is the most important part in a cyclotron construction. Though there are many codes devoted to solve magnetic field computation problems, the results from them depend on the user's skill and experience very much. To help cyclotron magnet designer to get acceptable results, an intelligent CAE (computer aided engineering) system for CYCLONE type cyclotron magnet design and machining has been developed. A reasonable good results in the design could be got even if the designer is a beginner, because of the help from an expert knowledge library installed in the program

Optimal Time Allocation in Backscatter Assisted Wireless Powered Communication Networks

Science.gov (United States)

Lyu, Bin; Yang, Zhen; Gui, Guan; Sari, Hikmet

2017-01-01

This paper proposes a wireless powered communication network (WPCN) assisted by backscatter communication (BackCom). This model consists of a power station, an information receiver and multiple users that can work in either BackCom mode or harvest-then-transmit (HTT) mode. The time block is mainly divided into two parts corresponding to the data backscattering and transmission periods, respectively. The users first backscatter data to the information receiver in time division multiple access (TDMA) during the data backscattering period. When one user works in the BackCom mode, the other users harvest energy from the power station. During the data transmission period, two schemes, i.e., non-orthogonal multiple access (NOMA) and TDMA, are considered. To maximize the system throughput, the optimal time allocation policies are obtained. Simulation results demonstrate the superiority of the proposed model. PMID:28587171

Radiation safety and quality control in the cyclotron laboratory

International Nuclear Information System (INIS)

Sharma, S.; Krause, G.; Ebadi, M.

2006-01-01

Radiation safety was determined to maintain quality control in the cyclotron laboratory. Based on the results of 438 runs in the Faraday cup (20 μA for 10 min), 20 runs on 18 O-water target (40 μA for 2 h) and 10 runs on 18 O-gas targets (30 μA for 45 min), we have established that occupationally exposed workers remain 10 ± 5 times below federal regulatory limits (FRLs) in the cyclotron vault, 30 ± 8 times below FRL in the radiochemistry laboratory and 200 ± 10 times below the FRL outside the cyclotron laboratory during beam operation. (The FRL for unrestricted area are <20 μSv in 1 h.) The non-occupationally exposed workers serving in offices in the vicinity of the cyclotron vault within 100 m distance remained 200 times below the FRL irrespective of beam being on or off, suggesting that routine beam operation of 40 μA for 2 h once a day during office hours is safe provided quality control and system performance measures as discussed in this report are strictly maintained. (authors)

New irradiation facilities at the Australian national medical cyclotron

International Nuclear Information System (INIS)

Parcell, S.K.; Arnott, D.W.; Conard, E.M.

1999-01-01

Two new irradiation facilities have been developed at the National Medical Cyclotron for radionuclide production. The first relocates PET irradiations from the cyclotron vault to a dedicated PET beam room, to improve accessibility and reduce radiation exposures associated with target maintenance. This new facility consists of a beam line to transport 16-30 MeV proton beams from the cyclotron to 1 of 8 PET targets mounted on a target rack. The target rack has increased the number of targets available for production and experimentation. The second is a completely independent solid target irradiation facility for SPECT. This facility consists of a beam line to transport 26-30 MeV proton beams from the cyclotron to a dedicated beam room containing one solid target station. A new pneumatic target transfer system was also developed to transport the solid target to and from the existing chemistry hot cells. The beam line and target components are operated under the control of a dedicated PLC with a PC based user interface. The development and some technical aspects of these new irradiation facilities are discussed here. (author)

Proceedings of the 12. Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Heating

International Nuclear Information System (INIS)

Giruzzi, Gerardo

2003-01-01

The 12. Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Heating was held in Aix-en-Provence (France) from 13 to 16 May 2002. The meeting was hosted by the Association Euratom-CEA sur la Fusion (CEA/Cadarache, France), with additional financial support from: - Region Provence-Alpes Cote d'Azur - The City of Aix-en-Provence - Communaute de l'Agglomeration du Pays d'Aix - Thales Electron Devices (France) - Alstom Magnets and Superconductors (France) - Spinner GmbH (Germany). The members of the local organizing committee were: G. Giruzzi, M. Lennholm, R. Magne and V. Poli, from CEA/Cadarache. The composition of the International Programme Committee was the following: M. Bornatici (Italy), A. Costley (ITER), E. de la Luna (Spain), G. Giruzzi (France), W. Kasparek (Germany), B. Lloyd (UK), J. Lohr (USA), K. Sakamoto (Japan). The subjects of the meeting were classified in four main topics: Electron Cyclotron Theory; Electron Cyclotron Emission; Electron Cyclotron Heating and Current Drive Experiments; Electron Cyclotron Technology. The results presented in these topics have been summarised in the closing session by E. Westerhof, A. Kraemer-Flecken, T. Goodman and G. Bosia, respectively. The workshop was attended by 85 participants from 18 countries, providing 10 invited talks, 30 oral presentations and 50 posters. The success of the workshop is mainly due to the amount and quality of their work and of their presentations. The generosity of the sponsors, the selection and advice work of the International Programme Committee, as well as the contribution of the chairmen and of the summary speakers should also be warmly acknowledged. The papers in this collection have been reproduced directly from the authors' manuscripts, provided either as camera-ready texts or as pdf files. The constraints on the papers lengths and formats have been kept to a minimum, on purpose. This series of workshops has now reached a good level of maturity, with well established

Interference phenomena at backscattering by ice crystals of cirrus clouds.

Science.gov (United States)

Borovoi, Anatoli; Kustova, Natalia; Konoshonkin, Alexander

2015-09-21

It is shown that light backscattering by hexagonal ice crystals of cirrus clouds is formed within the physical-optics approximation by both diffraction and interference phenomena. Diffraction determines the angular width of the backscattering peak and interference produces the interference rings inside the peak. By use of a simple model for distortion of the pristine hexagonal shape, we show that the shape distortion leads to both oscillations of the scattering (Mueller) matrix within the backscattering peak and to a strong increase of the depolarization, color, and lidar ratios needed for interpretation of lidar signals.

Nonlinear cyclotron-resonance accelerations by a generalized EM wave

International Nuclear Information System (INIS)

Akimoto, K.; Hojo, H.

2004-01-01

Particle accelerations by a one-dimensional, electromagnetic, dispersive pulse in an external magnetic field are investigated. It is found that the well-known cyclotron resonance may be classified into three regimes as the length and/or the amplitude of the pulse are varied. Namely, as the pulse amplitude increases, the transit-time cyclotron-resonance acceleration (CRA) evolves to phase trapping, and reflect particles. The amplitude and wave dispersion as well as the pulse length strongly affect those accelerations. The interesting phenomena of quantization of resonance velocities in between the two regimes are also investigated. This new mechanism may lead to wave amplification at some discrete frequencies other than the cyclotron frequency. (authors)

Surface Segregation in a Binary Mixture of Ionic Liquids: Comparison between High-Resolution RBS Measurements and Molecular Dynamics Simulations.

Czech Academy of Sciences Publication Activity Database

Nakajima, K.; Nakanishi, S.; Chval, Z.; Lísal, Martin; Kimura, K.

2016-01-01

Roč. 145, č. 18 (2016), s. 184704 ISSN 0021-9606 R&D Projects: GA ČR(CZ) GA16-12291S Institutional support: RVO:67985858 Keywords : rutherford backscattering spectroscopy * vapor interface * tensions Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.965, year: 2016

Degradation effects and Si-depth profiling in photoresists using ion beam analysis

NARCIS (Netherlands)

IJzendoorn, van L.J.; Schellekens, J.P.W.

1989-01-01

The reaction of silicon-containing vapour with a photoresist layer, as used in dry developable lithographic processes, was studied with Rutherford backscattering spectrometry (RBS). Degradation of the polymer layer was observed, but the total amount of incorporated Si was found to be constant during

Surface Structure of Imidazolium-based Ionic Liquids: Quantitative Comparison between Simulations and High-resolution RBS Measurements.

Czech Academy of Sciences Publication Activity Database

Nakajima, K.; Nakanishi, S.; Lísal, Martin; Kimura, K.

2016-01-01

Roč. 144, č. 11 (2016), s. 114702 ISSN 0021-9606 R&D Projects: GA ČR GA16-12291S Institutional support: RVO:67985858 Keywords : spectroscopy * rutherford backscattering spectroscopy * molten-salt Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.965, year: 2016

Backscatter and attenuation characterization of ventricular myocardium

Science.gov (United States)

Gibson, Allyson Ann

2009-12-01

This Dissertation presents quantitative ultrasonic measurements of the myocardium in fetal hearts and adult human hearts with the goal of studying the physics of sound waves incident upon anisotropic and inhomogeneous materials. Ultrasound has been used as a clinical tool to assess heart structure and function for several decades. The clinical usefulness of this noninvasive approach has grown with our understanding of the physical mechanisms underlying the interaction of ultrasonic waves with the myocardium. In this Dissertation, integrated backscatter and attenuation analyses were performed on midgestational fetal hearts to assess potential differences in the left and right ventricular myocardium. The hearts were interrogated using a 50 MHz transducer that enabled finer spatial resolution than could be achieved at more typical clinical frequencies. Ultrasonic data analyses demonstrated different patterns and relative levels of backscatter and attenuation from the myocardium of the left ventricle and the right ventricle. Ultrasonic data of adult human hearts were acquired with a clinical imaging system and quantified by their magnitude and time delay of cyclic variation of myocardial backscatter. The results were analyzing using Bayes Classification and ROC analysis to quantify potential advantages of using a combination of two features of cyclic variation of myocardial backscatter over using only one or the other feature to distinguish between groups of subjects. When the subjects were classified based on hemoglobin A1c, the homeostasis model assessment of insulin resistance, and the ratio of triglyceride to high-density lipoprotein-cholesterol, differences in the magnitude and normalized time delay of cyclic variation of myocardial backscatter were observed. The cyclic variation results also suggested a trend toward a larger area under the ROC curve when information from magnitude and time delay of cyclic variation is combined using Bayes classification than when

Trends and new applications in thin films

International Nuclear Information System (INIS)

1996-01-01

The proceedings of this symposium comprise 95 communications from which 64 were selected and fall into the scope of INIS subject categories, and 1 was selected for ETDE indexing. The selected communications deal with the techniques used for thin films preparation using chemical or physical vapor deposition techniques (plasma-arc or jet spraying, cathode sputtering, reactive DC or RF magnetron sputtering, plasma-ion deposition, ion implantation, electron or ion beam spraying, ion beam assisted plasma etching, dynamic ion mixing, distributed electron cyclotron resonance plasma sputtering, laser induced plasma sputtering etc..). The effects and interactions with the substrates (ion implantation, crystal growth, crystal-phase transformations, microstructures, penetration depth, changes in lattice parameters etc..) are analysed using various techniques such as grazing incidence X-ray diffraction, X-ray reflectometry, X-ray and angle resolved electron spectroscopy, Auger electron spectroscopy, Rutherford backscattering spectroscopy, SEM, TEM, IR absorption spectroscopy, UV or visible emission spectroscopy, conversion electron Moessbauer spectroscopy, X-ray fluorescence, mass spectroscopy, optical ellipsometry etc.. Mechanical tests such as scratch, microhardness and wear tests are also performed on the coatings to analyse their mechanical properties. (J.S.)

ECR ion source for variable energy cyclotron

Energy Technology Data Exchange (ETDEWEB)

Bose, D K; Taki, G S; Nabhiraj, P Y; Pal, G; Dasgupta, B; Mallik, C; Das, S K; Bandopadhaya, D K; Bhandari, R K [Variable Energy Cyclotron Centre, Calcutta (India)

1995-09-01

Some performance characteristics of 6.4 GHz two stage ECR ion source which was under development at this centre is presented. The present ion source will facilitate acceleration of light heavy ions with the existing k=130 variable energy cyclotron. Multiply charged heavy ion (MCHI) beam from the source will also be utilized for atomic physics studies. Oxygen beam has already been used for ion implantation studies. The external injection system under development is nearing completion. Heavy ion beam from cyclotron is expected by end of 1995. (author).

Radiation monitoring in a self-shielded cyclotron installation

International Nuclear Information System (INIS)

Capaccioli, L.; Gori, C.; Mazzocchi, S.; Spano, G.

2002-01-01

As nuclear medicine is approaching a new era with the spectacular growth of PET diagnosis, the number of medical cyclotrons installed within the major hospitals is increasing accordingly. Therefore modern medical cyclotron are highly engineered and highly reliable apparatus, characterised with reduced accelerating energies (as the major goal is the production of fluorine 18) and often self-shielded. However specific dedicated monitors are still necessary in order to assure the proper radioprotection. At the Careggi University Hospital in Florence a Mini trace 10 MeV self-shielded cyclotron produced by General Electric has been installed in 2000. In a contiguous radiochemistry laboratory, the preparation and quality control of 1 8F DG and other radiopharmaceuticals takes place. Aim of this work is the characterisation and the proper calibration of the above mentioned monitors and control devices

Process of a cyclotron modeling with SNOP program

International Nuclear Information System (INIS)

Smirnov, V.L.

2015-01-01

The description of the SNOP program developed in JINR and intended for numerical modeling of a beam dynamics in accelerating setups of cyclotron type is presented. The main methods of work with program components, and also stages of numerical modeling of a cyclotron, the analysis of the main characteristics of the accelerated bunch by means of the SNOP are given. The explanation of some algorithms and procedures used in the program is given. [ru

Support vector machine based fault detection approach for RFT-30 cyclotron

Energy Technology Data Exchange (ETDEWEB)

Kong, Young Bae, E-mail: ybkong@kaeri.re.kr; Lee, Eun Je; Hur, Min Goo; Park, Jeong Hoon; Park, Yong Dae; Yang, Seung Dae

2016-10-21

An RFT-30 is a 30 MeV cyclotron used for radioisotope applications and radiopharmaceutical researches. The RFT-30 cyclotron is highly complex and includes many signals for control and monitoring of the system. It is quite difficult to detect and monitor the system failure in real time. Moreover, continuous monitoring of the system is hard and time-consuming work for human operators. In this paper, we propose a support vector machine (SVM) based fault detection approach for the RFT-30 cyclotron. The proposed approach performs SVM learning with training samples to construct the classification model. To compensate the system complexity due to the large-scale accelerator, we utilize the principal component analysis (PCA) for transformation of the original data. After training procedure, the proposed approach detects the system faults in real time. We analyzed the performance of the proposed approach utilizing the experimental data of the RFT-30 cyclotron. The performance results show that the proposed SVM approach can provide an efficient way to control the cyclotron system.

Aerosol backscatter measurements at 10.6 microns with airborne and ground-based CO2 Doppler lidars over the Colorado High Plains. II - Backscatter structure

Science.gov (United States)

Bowdle, David A.; Rothermel, Jeffry; Vaughan, J. Michael; Post, Madison J.

1991-01-01

Measurements of tropospheric aerosol volume backscatter coefficients at 10.6-microns wavelength were obtained with airborne continuous wave and ground-based pulsed CO2 Doppler lidars over the Colorado High Plains during a 20-day period in summer 1982. A persistent 'background' layer was found between 6- and 10-km altitude, with a generally uniform backscatter mixing ratio of about 10 to the -10th sq m/kg per sr. The upper boundary of this background layer varied with the tropopause height; the lower boundary varied with the strength and diurnal cycle of convective mixing in the planetary boundary layer (PBL). For quiescent meteorological conditions, the transition from the PBL to the background layer was usually very sharp, with backscatter decreases sometimes as large as 3 decades in about 70 m. Sharp gradients were also found at the boundaries of shallow (tens of meters) subvisible cirrus clouds. For less stable conditions, associated with vertical aerosol transport by deep cumuliform clouds, backscatter tended to decrease exponentially with altitude.

Power deposition for ion cyclotron heating in large tokamaks

International Nuclear Information System (INIS)

Hellsten, T.; Villard, L.

1988-01-01

The power deposition profiles during minority ion cyclotron heating are analysed in large tokamaks by using the global, toroidal wave code LION. For tokamaks with large aspect ratio and with circular cross-section, the wave is focused on the magnetic axis and can be absorbed there by cyclotron absorption when the cyclotron resonance passes through the magnetic axis. The power deposition profile is then essentially determined by the Doppler broadening of the ion cyclotron resonance. For equilibria either non-circular or with a small aspect ratio the power deposition profile depends also on the strength of the damping. In this case the power deposition profile can be expressed as a sum of two power deposition profiles. One is related to the power absorbed in a single pass, and its shape is similar to that obtained for large aspect ratio and circular cross-section. The other profile is obtained by calculating the power deposition in the limit of weak damping, in which case the wave electric field is almost constant along the cyclotron resonance layer. A heuristic formula for the power deposition is given. The formula includes a number of calibration curves and functions which has been calculated with the LION code for JET relevant equilibria. The formula enables calculation of the power deposition profile in a simple way when the launched wave spectrum and damping coefficients are known. (author). 7 refs, 11 figs

Preparation and procedures of pre-commissioning on DECY-13 cyclotron

International Nuclear Information System (INIS)

Silakhuddin

2016-01-01

A preparation and procedures for pre-commissioning of DECY-13 Cyclotron have been discussed and the steps for these have been arranged. Pre-commissioning is a testing stage of individual subsystems when all subsystems have been integrated into a cyclotron system. The discussion was taken from references, the next the readiness of devices was studied and then the preparation and procedures of the pre-commissioning were arranged. The results of the discussion are that for doing the pre-commissioning of the cyclotron DECY-13 still requires the completion of RF-dee subsystem and some components for testing are still to be completed. (author)

Design features and operating characteristics of the MC-50 cyclotron

International Nuclear Information System (INIS)

Bak, Hae Ill; Bak, Joo Shik

1989-01-01

The MC-50 cyclotron at Korean Cancer Center Hospital is now operational for neutron therapy and medical radioisotope production. Design features, mechanical structures and operating characteristics of the MC-50 are described in this paper. Optimum operating condition for this cyclotron has been determined by the repetitive running, and the performances of the internal beam have been investigated through the measurements of intensity and spatial distribution of the internal beam as a function of the radius of the cyclotron. Routinely, the 40 μA of 50 MeV protons have been obtained at first Faraday cup with a extraction efficiency of 61%. (Author)

Use of maze in cyclotron hoppers

International Nuclear Information System (INIS)

Fernandes, Fernando A.; Alves, Juliano S.; Fochesatto, Cintia; Cerioli, Luciane; Borges, Joao Alfredo; Gonzalez, Delfin; Silva, Daniel C.

2013-01-01

Introduction: the increasing number of cyclotrons in Brazil due to constitutional amendment 49 /06 that enabled the production of radiopharmaceuticals with a short half - life by private companies. The radionuclides used for PET - CT require production centers near or within the diagnostic centers. In order to minimize maintenance and operating risks, gaining efficiency, our facility was the first in Brazil to use the access to a cyclotron bunker via maze, rather than armored door stopper type. Materials: the design calculations were based on the Monte Carlo method (MCNP5 - Monte Carlo N-Particletransportcode version 5). At the ends of the labyrinth are installed a door of polyethylene, for thermalization of neutrons, and other of wood for limiting access. Both legs of the maze have wall thickness of 100cm. In inspection Brazilian CNEN realize measures of dose rate for neutrons and gamma 9 points: 7 around the bunker, 1 over the bunker and 1 in the exhaust with the cyclotron operating with maximum load, double beam of 50uA for 2 hours. After commissioning were carried out around the bunker, the following measures: cumulative dose in three months with dosimeters for neutron rate dose with a gas proportional detector type filled with 3 He and polyethylene neutron moderator and dose rate with a Geiger - Mueller detector for gamma radiation. Readings with neutron detectors were classified as background radiation and dose rates were always below the limits established in standard EN 3.01, and the calculation of the predicted regardless of the intensity of irradiation inside the bunker. Conclusion: the use of labyrinths as a way to access the bunkers cyclotron has been shown to be effective as the radiation shielding and efficient by allowing quick and easy access, virtually eliminating the maintenance

Backscatter Correction Algorithm for TBI Treatment Conditions

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Nieto, B.; Sanchez-Doblado, F.; Arrans, R.; Terron, J.A. [Dpto. Fisiología Médica y Biofísica, Universidad de Sevilla, Avda. Sánchez Pizjuán, 4. E-41009, Sevilla (Spain); Errazquin, L. [Servicio Oncología Radioterápica, Hospital Univ.V. Macarena. Dr. Fedriani, s/n. E-41009, Sevilla (Spain)

2015-01-15

The accuracy requirements in target dose delivery is, according to ICRU, ±5%. This is so not only in standard radiotherapy but also in total body irradiation (TBI). Physical dosimetry plays an important role in achieving this recommended level. The semi-infinite phantoms, customarily used for dosimetry purposes, give scatter conditions different to those of the finite thickness of the patient. So dose calculated in patient’s points close to beam exit surface may be overestimated. It is then necessary to quantify the backscatter factor in order to decrease the uncertainty in this dose calculation. The backward scatter has been well studied at standard distances. The present work intends to evaluate the backscatter phenomenon under our particular TBI treatment conditions. As a consequence of this study, a semi-empirical expression has been derived to calculate (within 0.3% uncertainty) the backscatter factor. This factor depends lineally on the depth and exponentially on the underlying tissue. Differences found in the qualitative behavior with respect to standard distances are due to scatter in the bunker wall close to the measurement point.

Cyclotron/PET project in Uruguay

International Nuclear Information System (INIS)

Engler, H.

2006-01-01

The Positron Computed Tomography (PET) is a tri dimensional image technique which shows biochemical information. PET is used in neurology and cardiology diseases. The National Center Cyclotron PET has been found to research, development and health science applications.

Static harmonization of dynamically harmonized Fourier transform ion cyclotron resonance cell.

Science.gov (United States)

Zhdanova, Ekaterina; Kostyukevich, Yury; Nikolaev, Eugene

2017-08-01

Static harmonization in the Fourier transform ion cyclotron resonance cell improves the resolving power of the cell and prevents dephasing of the ion cloud in the case of any trajectory of the charged particle, not necessarily axisymmetric cyclotron (as opposed to dynamic harmonization). We reveal that the Fourier transform ion cyclotron resonance cell with dynamic harmonization (paracell) is proved to be statically harmonized. The volume of the statically harmonized potential distribution increases with an increase in the number of trap segments.

Modern compact cyclotrons for nuclear medicine designed and manufactured in NIIEFA

International Nuclear Information System (INIS)

Bogdanov, P.V.; Vasilchenko, I.N.; Gavrish, Yu.N.; Galchuk, A.V.; Grigorenko, S.V.; Kuzhlev, A.N.; Menshov, Yu.D.; Mudroyubov, V.G.; Ponomarenko, V.I.; Strokach, A.P.

2012-01-01

A series of compact cyclotrons, the CC-12, CC-18/9 and MCC-30/15, intended for the production of radionuclides for diagnostics and therapy directly in medical institutions has been designed and manufactured in NIIEFA. These cyclotrons provide the acceleration of negative hydrogen and deuterium ions injected from external sources. Beams of accelerated particles are extracted by stripping negative ions to protons and deuterons by carbon foils. Shielding-type electromagnets with the vertically located median plane are applied in these cyclotrons.

Modular beam diagnostics instrument design for Cyclotrons

International Nuclear Information System (INIS)

Chaddha, N.; Bhole, R.B.; Sahoo, S.; Nandy, P.P.; Pal, S.

2012-01-01

The Cyclotrons at VECC, Kolkata i.e. Room Temperature Cyclotron (RTC) and Superconducting Cyclotron (SCC) comprise of internal and external Beam Diagnostic systems. These systems provide the beam developer with position, intensity, beam profile, a visual impression of the size and shape of ion beam, and operational control over diagnostic components like 3-finger probe, Beam Viewer probe, Deflector probe, Faraday cup, X-Y slit, Beam viewer etc. Automation of these components was initially done using customised modules for individual sub-system. An expansion of this facility and various levels of complexity demand modular design to cater easy modification and upgradation. The overall requirements are analysed and modular cards are developed based on basic functionalities like valve operation, probe/slit/viewer control, position read-out, Interlock, aperture control of beam line and communication. A 32-bit Advanced RISC Machine (ARM) based card with embedded EPICS is chosen as the master controller and FPGA/microcontroller is used for functional modules. The paper gives a comprehensive description of all modules and their integration with the control system. (author)

Technical Note: Building a combined cyclotron and MRI facility: Implications for interference

Energy Technology Data Exchange (ETDEWEB)

Hofman, Mark B. M.; Kuijer, Joost P. A.; Ridder, Jan Willem de; Perk, Lars R.; Verdaasdonk, Rudolf M. [Physics and Medical Technology, VU University Medical Center, Amsterdam 1007 MB (Netherlands) and BV Cyclotron VU, Amsterdam 1081HV (Netherlands)

2013-01-15

Purpose: With the introduction of hybrid PET/MRI systems, it has become more likely that the cyclotron and MRI systems will be located close to each other. This study considered the interference between a cyclotron and a superconducting MRI system. Methods: Interactions between cyclotrons and MRIs are theoretically considered. The main interference is expected to be the perturbation of the magnetic field in the MRI due to switching on or off the magnetic field of the cyclotron. MR imaging is distorted by a dynamic spatial gradient of an external inplane magnetic field larger than 0.5-0.04 {mu}T/m, depending on the specific MR application. From the design of a cyclotron, it is expected that the magnetic fringe field at large distances behaves as a magnetic dipolar field. This allows estimation of the full dipolar field and its spatial gradients from a single measurement. Around an 18 MeV cyclotron (Cyclone, IBA), magnetic field measurements were performed on 5 locations and compared with calculations based upon a dipolar field model. Results: At the measurement locations the estimated and measured values of the magnetic field component and its spatial gradients of the inplane component were compared, and found to agree within a factor 1.1 for the magnetic field and within a factor of 1.5 for the spatial gradients of the field. In the specific case of the 18 MeV cyclotron with a vertical magnetic field and a 3T superconducting whole body MR system, a minimum distance of 20 m has to be considered to prevent interference. Conclusions: This study showed that a dipole model is sufficiently accurate to predict the interference of a cyclotron on a MRI scanner, for site planning purposes. The cyclotron and a whole body MRI system considered in this study need to be placed more than 20 m apart, or magnetic shielding should be utilized.

Computer modeling of magnetic structure for IC-35 cyclotron

International Nuclear Information System (INIS)

Alenitskij, Yu.G.; Morozov, N.A.

1998-01-01

An extensive series of calculations has been carried out in order to design the magnetic structure of the IC-35 cyclotron for radioisotope production. The calculations were carried out by 2-D POISCR code. The average magnetic field and its variation were produced with the help of two different calculation models. The parameters of the cyclotron magnetic system are presented

Electron cyclotron waves, transport and instabilities in hot plasmas

International Nuclear Information System (INIS)

Westerhof, E.

1987-01-01

A number of topics relevant to the magnetic confinement approach to the thermonuclear fusion is addressed. The absorption and emission of electron cyclotron waves in a thermal plasma with a small population of supra-thermal, streaming electrons is examined and the properties of electron cyclotron waves in a plasma with a pure loss-cone distribution are studied. A report is given on the 1-D transport code simulations that were performed to assist the interpretation of the electron cyclotron heating experiments on the TFR tokamak. Transport code simulations of sawteeth discharges in the T-10 tokamak are discussed in order to compare the predictions of different models for the sawtooth oscillations with the experimental findings. 149 refs.; 69 figs.; 7 tabs

The Medical Cyclotron Facility in RMC, Parel, BARC

International Nuclear Information System (INIS)

Gopalakrishna, Arjun; Banerjee, Sharmila

2017-01-01

The Medical Cyclotron Facility in Radiation Medicine Centre (RMC) is the first one of its kind, installed in 2002. "1"8F based radiotracers are produced in this facility on a routine basis for Positron Emission Tomography (PET), of in-house patients, as well as for supply to other nuclear medicine centers in Mumbai as well as Pune. The facility consists of the following sub parts - Cyclotron and support equipment; Radiochemistry synthesis laboratory; Quality control (QC) laboratory

Parameters of the eigenellipsoid for separated sector cyclotrons

International Nuclear Information System (INIS)

Ferme, J.

1989-01-01

The analytical expressions of the elements of the beam matrix corresponding to the eigenellipsoid for a beam injected on an equilibrium orbit of a cyclotron are presented. The four dimensional phase space of the horizontal plane is only considered. Some restrictive hypotheses are made: there is no acceleration, and space charge effects are not taken into account. The beam matrix has been computed for the general case of spiraled sectors cyclotrons, and is valid for any given azimuth

Electromagnetic Cyclotron Waves in the Solar Wind: Wind Observation and Wave Dispersion Analysis

Science.gov (United States)

Jian, L. K.; Moya, P. S.; Vinas, A. F.; Stevens, M.

2016-01-01

Wind observed long-lasting electromagnetic cyclotron waves near the proton cyclotron frequency on 11 March 2005, in the descending part of a fast wind stream. Bi-Maxwellian velocity distributions are fitted for core protons, beam protons, and alpha-particles. Using the fitted plasma parameters we conduct kinetic linear dispersion analysis and find ion cyclotron and/or firehose instabilities grow in six of 10 wave intervals. After Doppler shift, some of the waves have frequency and polarization consistent with observation, thus may be correspondence to the cyclotron waves observed.

Card controlled beta backscatter thickness measuring instrument

International Nuclear Information System (INIS)

Schlesinger, J.

1978-01-01

An improved beta backscatter instrument for the nondestructive measurement of the thickness of thin coatings on a substrate is described. Included therein is the utilization of a bank of memory stored data representative of isotope, substrate, coating material and thickness range characteristics in association with a control card having predetermined indicia thereon selectively representative of a particular isotope, substrate material, coating material and thickness range for conditioning electronic circuit means by memory stored data selected in accord with the predetermined indicia on a control card for converting backscattered beta particle counts into indicia of coating thickness

Depth profiling of extended defects in silicon by Rutherford backscattering measurements

International Nuclear Information System (INIS)

Gruska, B.; Goetz, G.

1981-01-01

Depth profiling of dislocations and stacking faults is carried out by analyzing axial and planar channeling data from As + -and P + -implanted silicon samples annealed at high temperatures. The analyzing procedure is based on the simple two-beam model. The results show that depth profiling of dislocations using planar channeling data is connected with a broadening of the real distributions. A degradation of the defect concentration and a deformation of the profile result for very high defect concentrations (> 5 x 10 5 cm/cm 2 ). All these effects can be neglected by analyzing axial channeling data. Depth profiling of stacking faults is restricted to the determination of the depth distribution of displaced atomic rows or planes. For both the procedures, axial as well as planar channeling measurements, the same depth profiles of displaced atomic rows are obtained. (author)

Summary of EC-17: the 17th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating (Deurne, The Netherlands, 7-10 May 2012)

NARCIS (Netherlands)

Westerhof, E.; Austin, M. E.; Kubo, S.; Lin-Liu, Y. R.; Plaum, B.

2013-01-01

An overview is given of the papers presented at the 17th Joint Workshop on Electron Cyclotron Emission (ECE) and Electron Cyclotron Resonance Heating (ECRH). The meeting covered all aspects of the research field ranging from theory to enabling technologies. From the workshop, advanced control by

Magnetic phenomena in F.F.A.G. cyclotrons; Phenomenes magnetiques dans les cyclotrons F.F.A.G

Energy Technology Data Exchange (ETDEWEB)

Beurtey, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

This study regroups and develops some experimental and theoretical results obtained with spiral tract cyclotrons. The method used has been studied previously by C. BLOCH, whom we thank for his helpful advice. We have tried to give the main useful results, which are also in accordance with the rather scarce experimental results obtained on spiral pole pieces. (author) [French] Cette etude regroupe et developpe des resultats experimentaux et theoriques sur les cyclotrons 'spirales'. La methode employee est celle etudiee par C. BLOCH, que nous remercions vivement pour sa bienveillance et ses conseils. Nous avons essaye de donner les resultats essentiels a la fois utilisables et compatibles avec les resultats experimentaux peu nombreux sur les pieces polaires spiralees. (auteur)

Multiple scattering wavelength dependent backscattering of kaolin dust in the IR: Measurements and theory

Science.gov (United States)

Ben-David, Avishai

1992-01-01

Knowing the optical properties of aerosol dust is important for designing electro-optical systems and for modeling the effect on propagation of light in the atmosphere. As CO2 lidar technology becomes more advanced and is used for multiwavelength measurements, information on the wavelength dependent backscattering of aerosol dust particles is required. The volume backscattering coefficient of aerosols in the IR is relatively small. Thus, only a few field measurements of backscattering, usually at only a few wavelengths, are reported in the literature. We present spectral field measurements of backscattering of kaolin dust in the 9-11 micron wavelength range. As the quantity of dust increases, multiple scattering contributes more to the measured backscattered signal. The measurements show the effect of the dust quantity of the spectral backscatter measurements. A simple analytical two stream radiative transfer model is applied to confirm the measurements and to give insight to the multiple scattering spectra of backscattering.

Nonlinear analysis of a relativistic beam-plasma cyclotron instability

Science.gov (United States)

Sprangle, P.; Vlahos, L.

1986-01-01

A self-consistent set of nonlinear and relativistic wave-particle equations are derived for a magnetized beam-plasma system interacting with electromagnetic cyclotron waves. In particular, the high-frequency cyclotron mode interacting with a streaming and gyrating electron beam within a background plasma is considered in some detail. This interaction mode may possibly find application as a high-power source of coherent short-wavelength radiation for laboratory devices. The background plasma, although passive, plays a central role in this mechanism by modifying the dielectric properties in which the magnetized electron beam propagates. For a particular choice of the transverse beam velocity (i.e., the speed of light divided by the relativistic mass factor), the interaction frequency equals the nonrelativistic electron cyclotron frequency times the relativistic mass factor. For this choice of transverse beam velocity the detrimental effects of a longitudinal beam velocity spread is virtually removed. Power conversion efficiencies in excess of 18 percent are both analytically calculated and obtained through numerical simulations of the wave-particle equations. The quality of the electron beam, degree of energy and pitch angle spread, and its effect on the beam-plasma cyclotron instability is studied.

Digital control in LLRF system for CYCIAE-100 cyclotron

Energy Technology Data Exchange (ETDEWEB)

Yin, Zhiguo, E-mail: bitbearAT@hotmail.com; Fu, Xiaoliang; Ji, Bin; Zhang, Tianjue; Wang, Chuan

2016-05-21

As a driven accelerator, the CYCIAE-100 cyclotron is designed by China Institute of Atomic Energy for the Beijing Radio Ion-beam Facility project. The cyclotron RF system is designed to use two RF power sources of 100 kW to drive two half-wavelength cavities respectively. Two Dee accelerating electrodes are kept separately from each other inside the cyclotron, while their accelerating voltages are maintained in phase by the efforts of LLRF control. An analog–digital hybrid LLRF system has been developed to achieve cavity tuning control, dee voltage amplitude and phase stabilization etc. The analog subsystems designs are focused on RF signal up/down conversion, tuning control, and dee voltage regulation. The digital system provides an RF signal source, aligns the cavity phases and maintains a Finite State Machine. The digital parts combine with the analog functions to provide the LLRF control. A brief system hardware introduction will be given in this paper, followed by the review of several major characteristics of the digital control in the 100 MeV cyclotron LLRF system. The commissioning is also introduced, and most of the optimization during the process was done by changing the digital parts.

New development of neutron radiography with a small cyclotron

International Nuclear Information System (INIS)

Ikeda, Yasushi; Ohkubo, Kohei; Kato, Toshihiko; Nakamura, Tomihisa; Fuji, Takayoshi.

1990-01-01

A series of neutron radiography testing has been performed for several years by using a small accelerator called 'Baby Cyclotron' manufactured by Japan Steel Works, Ltd. The Baby Cyclotron produces fast neutrons at the rate of 4x10 12 n/cm 2 s, and enables to perform neutron radiography imaging by various techniques. The most important application of this Baby Cyclotron radiography system is the non-destructive testing (NDT) of various explosive devices prepared for space launch vehicles. It is assured that thermal neutron radiography testing is a very useful means for the NDT. Also fast neutron radiography testing is in progress. The fast neutron radiography with a CR39 track-etch image recorder was developed, and it was shown to be the very useful NDT means when the thicker objects used for new H-2 launch vehicles had to be examined. Because thermal neutron radiography has the high detectability of hydrogenous materials, organic elastomers such as O-rings and explosive powder are clearly observable through the opaque steel walls of containers. The Baby Cyclotron and the neutron radiography facility, thermal neutron and fast neutron radiography testings and so on are reported. (K.I.)

Materials analysis with a nuclear microprobe

International Nuclear Information System (INIS)

Maggiore, C.J.

1980-01-01

The ability to produce focused beams of a few MeV light ions from Van de Graaff accelerators has resulted in the development of nuclear microprobes. Rutherford backscattering, nuclear reactions, and particle-induced x-ray emission are used to provide spatially resolved information from the near surface region of materials. Rutherford backscattering provides nondestructive depth and mass resolution. Nuclear reactions are sensitive to light elements (Z < 15). Particle-induced x-ray analysis is similar to electron microprobe analysis, but 2 orders of magnitude more sensitive. The focused beams are usually produced with specially designed multiplets of magnetic quadrupoles. The LASL microprobe uses a superconducting solenoid as a final lens. The data are acquired by a computer interfaced to the experiment with CAMAC. The characteristics of the information acquired with a nuclear microprobe are discussed; the means of producing the beams of nuclear particles are described; and the limitations and applications of such systems are given

Thermochemical properties of media for pyrometallurgical nuclear fuel reprocessing

International Nuclear Information System (INIS)

Hosoya, Yuji; Terai, Takayuki

1998-01-01

Molten chloride/cadmium system is considered to be applied to a solvent in pyrochemical reprocessing of spent nuclear fuel. In this work, phase diagrams for molten chloride systems were constructed, using NdCl 3 as an imitative substance in place of UCl 3 or PuCl 3 . Hastelloy-X (Ni/Cr21/Fe18/Mo9/W) was examined as a structural material for the corrosion-resistance against molten chloride baths containing NdCl 3 . The process of corrosion was thermochemically discussed and the form of the corrosion was illustrated. Rutherford backscattering spectroscopy was successfully applied to determine the elemental distribution profile of specimens tested on the compatibility with molten chloride mixture at elevated temperature. Ferritic steel was also examined as another candidate material for the compatibility with molten cadmium covered with LiCl-KCl eutectic salt. Variation of near-surface composition was observed by comparing the results of Rutherford backscattering spectroscopy obtained before and after the dipping. (author)

MEASURING THE PARTICULATE BACKSCATTERING OF INLAND WATERS: A COMPARISON OF TECHNIQUES

Directory of Open Access Journals (Sweden)

G. Campbell

2012-07-01

Full Text Available The objective of this work was to examine whether the standard particulate backscattering IOP (Inherent Optical Properties measurement method could be simplified. IOP measurements are essential for parameterising several forms of algorithms used to estimate water quality parameters from airborne and satellite images. Field measurements of the backscattering IOPs are more difficult to make than absorption measurements as correction of the raw Hydroscat-6 backscattering sensor observations is required to allow for the systematic errors associated with the water and water quality parameter absorption. The standard approach involves making simultaneous measurement of the absorption and attenuation of the water with an absorption and attenuation meter (ac-9 or making assumptions about the particulate backscattering probability. Recently, a number of papers have been published that use an alternative method to retrieve the particulate backscattering spectrum by using laboratory measured absorption values and in situ spectroradiometric observations. The alternative method inverts a model of reflectance iteratively using non-linear least squares fitting to solve for the particulate backscattering at 532 nm (bbp0(532 and the particulate backscattering spectral slope (γ. In this paper, eleven observations made at Burdekin Falls Dam, Australia are used to compare the alternative reflectance method to the conventional corrected Hydroscat-6 observations. Assessment of the alternative reflectance method showed that the result of the inversions were highly dependent on the starting conditions. To overcome this limitation, Particle Swarm Optimisation, a stochastic search technique which includes a random element in the search approach, was used. It was found that when compared to the conventionally corrected Hydroscat-6 observations, the alternative reflectance method underestimated bbp0(532 by approximately 50% and overestimated γ by approximately 40

Calculation of the neutrons shielding in cyclotron accelerator

International Nuclear Information System (INIS)

Ribeiro, Martha S.; Sanches, Matias P.; Rodrigues, Demerval L.

2000-01-01

The objective of radioprotection in cyclotron facilities is to reduce the dose levels in the workplaces to classify them like supervised areas. In this way, the radiation dose rates in areas occupied by workers during cyclotron operations should not exceed 7,5 μSv/h. In controlled areas these levels are not observed and some rigorous controls must be exerted by administrative procedures or protection mechanisms. The Cyclotron Laboratory at IPEN-CNEN/SP has a cyclotron model Cyclone 30, 30 MeV, used for research and it is also used for radioisotopes production for medical diagnosis and therapeutical applications. Among them, 123 I, 67 Ga and 18 F can be pointed. When accelerator is operating, failures in perforations and paths that conduce to room accelerator can be occur and thus, the dose levels are higher than that established by law. For this reason, a review for shielding structure was necessary in order to optimize radiation dose. The purpose of this work was to determine the shielding thickness and adequate material to diminish the dose rates in workplaces to a value below 7,5 μSv/h. It was used a method to employ the equivalent dose value in the facility areas for neutrons fluency rate for the principal reactions in target irradiation processes. The purposed shielding for the vault doors ensures dose levels lower than established limits to supervised areas. (author)

Analytical purpose electron backscattering system

International Nuclear Information System (INIS)

Desdin, L.; Padron, I.; Laria, J.

1996-01-01

In this work an analytical purposes electron backscattering system improved at the Center of Applied Studies for Nuclear Development is described. This system can be applied for fast, exact and nondestructive testing of binary and AL/Cu, AL/Ni in alloys and for other applications

An investigation into the technical feasibility of cyclotron production of technetium-99m

International Nuclear Information System (INIS)

Egan, G.F.; Lagunas-Solar, M.C.

1994-01-01

The role of technetium-99m in nuclear medicine is well established with 80 per cent to 90 per cent of all nuclear medicine studies utilising this isotope. Technetium-99m is currently produced from nuclear reactors via production of the parent radionuclide molybdenum-99. The reactor production of 99m Tc has both significant financial and environmental costs, with unresolved problems in the areas of radioactive waste disposal and reactor decommissioning. Recent scientific publications have indicated that medical quality 99m Tc may be produced using cyclotrons without having the associated problems of waste disposal and decommissioning. Further scientific research is now required to demonstrate the feasibility of this cyclotron production technique. A collaboration between the Cyclotron and PET Centre, Austin Hospital, the National Medical Cyclotron, ANSTO, Sydney, and the Crocker Nuclear Laboratory, University of California, Davis, USA has been proposed. The general objective of the proposed collaboration is to acquire additional scientific data to evaluate the 99m Tc cyclotron production method and to determine the feasibility of cyclotron technology for Australian nuclear medicine. 16 refs., 2 tabs

Rutherford Memorial Lecture, 1977. Some episodes of the α-particle story, 1903-1977

International Nuclear Information System (INIS)

Feather, N.

1977-01-01

In this lecture an episodic account of more than seventy years experimental and theoretical α -particle physics is given, largely centred on the work of Rutherford and his colleagues but also including recent advances in the subject. Amongst the episodes included are, the birth of α- radiation in the winter of 1902 -3 when α - radiation finally assumed the character of a stream of 'charged bodies projected with a great velocity', work on measuring the α - particle charge, the discovery of the nucleus, scattering experiments, work on long-range α - Particles, and lastly α - particles in fission. (U.K.)

Power Control for Passive QAM Multisensor Backscatter Communication Systems

Directory of Open Access Journals (Sweden)

Shengbo Hu

2017-01-01

Full Text Available To achieve good quality of service level such as throughput, power control is of great importance to passive quadrature amplitude modulation (QAM multisensor backscatter communication systems. First, we established the RF energy harvesting model and gave the energy condition. In order to minimize the interference of subcarriers and increase the spectral efficiency, then, the colocated passive QAM backscatter communication signal model is presented and the nonlinear optimization problems of power control are solved for passive QAM backscatter communication systems. Solutions include maximum and minimum access interval, the maximum and minimum duty cycle, and the minimal RF-harvested energy under the energy condition for node operating. Using the solutions above, the maximum throughput of passive QAM backscatter communication systems is analyzed and numerical calculation is made finally. Numerical calculation shows that the maximal throughput decreases with the consumed power and the number of sensors, and the maximum throughput is decreased quickly with the increase of the number of sensors. Especially, for a given consumed power of sensor, it can be seen that the throughput decreases with the duty cycle and the number of sensors has little effect on the throughput.

First results of beam generation test for JAERI AVF cyclotron

International Nuclear Information System (INIS)

Tachikawa, T.; Hayashi, Y.; Ishii, K.

1992-01-01

The performance of JAERI AVF cyclotron was investigated with several kinds of ions in the wide energy range. The 90 MeV protons of 10 μA intensity was successfully extracted for the first time by the model 930 cyclotron. The feature of beam chopping system is also presented. (author)

Optimisation of the radiation shielding of medical cyclotrons using a genetic algorithm

International Nuclear Information System (INIS)

Mukherjee, Bhaskar

2000-01-01

Effective radiation shielding is imperative for safe operation of modern Medical Cyclotrons producing large activities of short-lived radioisotopes on a commercial basis. The optimal cyclotron shielding design demands a careful balance between the radiological, economical and often the sociopolitical factors. One is required to optimize the cost of radiation protection and the cost of radiological-health detriment. The cost of radiation protection depends explicitly on a) the nature of the radiation field produced by the cyclotron, b) the cyclotron operation condition, c) the cost of shielding material, d) the level of dose reduction, e) the projected net revenue from the sale of the radioisotopes, and f) the depreciation rate of the cyclotron facility. The Genetic Algorithm (GA) is used for a cost -benefit analysis of this problem. The GA is a mathematical technique that emulates the Darwinian Evolution paradigm. It is ideally suited to search for a global optimum in a large multi-dimensional solution space, having demonstrated strength compared to the classical analytical methods. Furthermore the GA method runs on a PC in a Windows environment. This paper highlights an interactive spreadsheet macro program for the cost benefit analysis of the optimize Medical Cyclotron shielding using a GA search engine. (author)

Study of axial injection of polarized protons into the grenoble cyclotron

International Nuclear Information System (INIS)

Pabot, J.

1969-01-01

By injecting ions axially into a cyclotron, it is possible to accelerate particles (polarized particles, heavy ions, etc...) obtainable only with difficulty when an internal ion source is used. In this work, after justifying the choice of an axial injection device equipped with a 'pseudo-cylindrical' deflector for the Grenoble cyclotron, we study theoretically the principle of such a detector, the choice of its parameters, and the effect of this choice on the conditions of acceleration of the beam by the cyclotron. From the experimental point of view, this report describes two operations which made it possible to check that the chosen injection device operated satisfactorily, qualitatively initially (electron model), then quantitatively (proton model). In conclusion, we believe that the Grenoble cyclotron thus equipped will be able to provide a relatively dense beam of polarized protons. (author) [fr

Atmospheric tracer study of the emissions from the University of Michigan Cyclotron/PET Facility

International Nuclear Information System (INIS)

Scofield, P.A.

1986-01-01

The University of Michigan (U of M) Cyclotron/Positron Emission Tomography (PET) facility consists of a cyclotron (Model CS-30, The Cyclotron Corporation), radiochemistry laboratory, and Pet scanner. Accelerator-produced radioactive materials, such as, carbon-11 and oxygen-15 are typically emitted from the Cyclotron/PET facility through short stacks located on the roof. This project studied the dispersion of emissions from the facility within the medical complex. To achieve this purpose, the research project had three phases: a physical modeling study; a preliminary field smoke release study; and, a field study using a tracer gas to simulate emission dispersion from the U of M Cyclotron/PET facility vault stack. The objective was to determine normalized concentrations, under selected wind directions and speeds, for use in establishing radionuclide concentrations at the air intakes of the Cyclotron/PET facility and surrounding buildings and at selected ground-level locations

Damage by the Great East Japan Earthquake and current status of the Sendai cyclotron

International Nuclear Information System (INIS)

Wakui, Takashi; Itoh, Masatoshi; Shimada, Kenzi; Yoshida, Hidetomo; Shinozuka, Tsutomu; Sakemi, Yasuhiro

2012-01-01

The Great East Japan Earthquake has inflicted damages on the accelerator facility of the Cyclotron and Radioisotope Center (CYRIC), Tohoku University. The K=110 MeV cyclotron was slanted due to the damage of props supporting the cyclotron. The cyclotron building has also been slightly inclined. This situation requires the re-alignment of all the beam transport line and the cyclotron. Some of the shield doors at experimental rooms were broken and blocked the entrance. The earthquake caused also a lot of damages to some components of the cyclotron as well as the beam transport lines, such as beam ducts, magnets, vacuum pumps and power supplies. Fortunately, no one was injured at CYRIC. The restoration work was started on July 2011 and will be completed by July 2012. This report describes the situation of damages and the current status of the restoration work. (author)

Princeton Cyclotron QDDD spectrograph system

International Nuclear Information System (INIS)

Kouzes, R.T.

1985-01-01

A review of experiments involving the Princeton Quadrupole-Dipole-Dipole- Dipole (QDDD) spectrograph is given. The QDDD is a high resolution, large solid angle device which is combined with the azymuthally varying field (AVF) cyclotron. Some reactions involving 3 He beams are discussed

Neutron radiography with the cyclotron

International Nuclear Information System (INIS)

Tazawa, Shuichi; Asada, Yorihisa; Yano, Munehiko; Nakanii, Takehiko.

1985-01-01

Neutron radiography is well recognized as a powerful tool in nondestructive testing, but not widely used yet owing to lack of high intense thermal neutron source convenient for practical use. This article presents a new neutron radiograph facility, utilizing a sub-compact cyclotron as neutron source and is equipped with vertical and horizontal irradiation ports. The article describes a series of experiments, we conducted using beams of a variable energy cyclotron at Tohoku University to investigate the characteristics of thermal neutron obtained from 9 Be(p, n) reaction and thermalized by elastic scattering process. The article also describes a computer simulation of neutron moderator to analyze conditions getting maximal thermal neutron flux. Further, some of practical neutron radiograph examinations of aero-space components and museum art objects of classic bronze mirror and an attempt realizing real time imaging technique, are introduced in the article. (author)

Cyclotron radiation from hot plasmas

International Nuclear Information System (INIS)

Pohl, F.; Henning, J.; Duechs, D.

1975-11-01

In calculating the energy transport and losses due to cyclotron radiation there are two major requirements: the absorption coefficient has to be known and the proper geometry of the plasma has to be taken into account. In this report Trubnikov's integral formulae for the absorption coefficient have been evaluated numerically and compared with the approximative formulas of previous authors. Deviations by a factor of 2 - 10 in various frequency regimes are not unusual. With these coefficients the rate of change of the energy density due to cyclotron radiation in a plasma as well as the radiation density at a plasma surface are computed for plasma slab and plasma cylinder. Sometimes considerable differences to the results of previons papers can found. Many simple formulae interpolating the numerical results are given in the text, and the FORTRAN computer programs have been reproduced in the appendices. (orig.) [de

Radioisotope production by reactors and cyclotrons in Japan

International Nuclear Information System (INIS)

Murakami, Yukio

1978-01-01

Present status of radioisotope production in Japan and the increasing demand from various fields are generally reviewed. Future problems associated with the shortage of economical supply are also discussed. The first half of this report is devoted to general review of the increasing demand for various radioisotopes from increasing number of users. The present status and future trends of the distribution of users of specific radioisotopes and their demands are shown. The remaining half of this report reviews the production with reactors and cyclotrons. The Japanese reactors producing radioisotopes are limited to low flux (10 13 ) research reactors at JAERI. Some problems associated with the improvement of availability and with the organizational structure are discussed. As for the production with cyclotrons, available facilities and the method of production are explained in detail. For clinical use, especially for the production of short lived radioisotopes, the advantage of a small special purpose cyclotron at each medical organization is emphasized. (Aoki, K.)

Transparency of Magnetized Plasma at Cyclotron Frequency; TOPICAL

International Nuclear Information System (INIS)

G. Shvets; J.S. Wurtele

2002-01-01

Electromagnetic radiation is strongly absorbed by a magnetized plasma if the radiation frequency equals the cyclotron frequency of plasma electrons. It is demonstrated that absorption can be completely canceled in the presence of a magnetostatic field of an undulator or a second radiation beam, resulting in plasma transparency at the cyclotron frequency. This effect is reminiscent of the electromagnetically induced transparency (EIT) of the three-level atomic systems, except that it occurs in a completely classical plasma. Unlike the atomic systems, where all the excited levels required for EIT exist in each atom, this classical EIT requires the excitation of the nonlocal plasma oscillation. The complexity of the plasma system results in an index of refraction at the cyclotron frequency that differs from unity. Lagrangian description was used to elucidate the physics and enable numerical simulation of the plasma transparency and control of group and phase velocity. This control naturally leads to applications for electromagnetic pulse compression in the plasma and electron/ion acceleration

Wave propagation through an electron cyclotron resonance layer

International Nuclear Information System (INIS)

Westerhof, E.

1997-01-01

The propagation of a wave beam through an electron cyclotron resonance layer is analysed in two-dimensional slab geometry in order to assess the deviation from cold plasma propagation due to resonant, warm plasma changes in wave dispersion. For quasi-perpendicular propagation, N ' 'parallel to'' ≅ v t /c, an O-mode beam is shown to exhibit a strong wiggle in the trajectory of the centre of the beam when passing through the fundamental electron cyclotron resonance. The effects are largest for low temperatures and close to perpendicular propagation. Predictions from standard dielectric wave energy fluxes are inconsistent with the trajectory of the beam. Qualitatively identical results are obtained for the X-mode second harmonic. In contrast, the X-mode at the fundamental resonance shows significant deviations form cold plasma propagation only for strongly oblique propagation and/or high temperatures. On the basis of the obtained results a practical suggestion is made for ray tracing near electron cyclotron resonance. (Author)

Control philosophy and diagnostic systems of Superconducting Cyclotron

International Nuclear Information System (INIS)

Roy, Anindya; Bhattacharjee, Tanushyam; Chaddha, N.; Bhole, R.B.; Pal, Sarbajit; Samanta, N.C.; Dutta, C.D.; Mukhopadhyay, B.; Panda, U.S.; Sarkar, B.; Nabhiraj, P.Y.; Sarkar, D.

2009-01-01

The control system has the primary task of monitoring and control of all the important parameters of a machine comprises of various sub-systems. The paper describes the philosophy of the distributed control system of Superconducting Cyclotron implemented with the support of reliable and fast control network. The paper also describes the field hardware interfaced with various software platforms at different levels of individual sub-systems e.g. Main Magnet Power Supply, Trim-coil Power Supplies, He Liquefier/Refrigerator Plant, Cryogen Delivery System, RF System, ECR Ion source, Vacuum System, Radiation Monitoring System, Alarm Annunciation System, LCW System of SC Cyclotron. The database management system facilitating the exchange of control data among the sub-systems, serving as primary source of information to understand the behavior of the cyclotron, is also discussed. A brief description of various beam diagnostic instruments and their respective control systems e.g. Main Probe, Borescope, Beam viewer, Magnetic channel control system, Beam line slit control system, are briefly described. (author)

Ernest Orlando Lawrence (1901-1958), Cyclotron and Medicine

Energy Technology Data Exchange (ETDEWEB)

Chu, William T.

2005-09-01

On August 8, 2001, Lawrence Berkeley National Laboratory celebrated the centennial of the birth of its founder (and namesake), Ernest Orlando Lawrence. For the occasion, many speeches were given and old speeches were remembered. We recall the words of the late Luis Alvarez, a Nobel Laureate and one of the Lawrence's closest colleagues: ''Lawrence will always be remembered as the inventor of the cyclotron, but more importantly, he should be remembered as the inventor of the modern way of doing science''. J. L. Heilbron and R. W. Seidel, in the introduction of their book, ''Lawrence and His Laboratory'' stated, ''The motives and mechanisms that shaped the growth of the Laboratory helped to force deep changes in the scientific estate and in the wider society. In the entrepreneurship of its founder, Ernest Orlando Lawrence, these motives, mechanisms, and changes came together in a tight focus. He mobilized great and small philanthropists, state and local governments, corporations, and plutocrats, volunteers and virtuosos. The work they supported, from astrophysics and atomic bombs, from radiochemistry to nuclear medicine, shaped the way we observe, control, and manipulate our environment.'' Indeed, all over the civilized world, the ways we do science changed forever after Lawrence built his famed Radiation Laboratory. In this editorial, we epitomize his legacy of changing the way we do medicine, thereby affecting the health and well being of all humanity. This year marks the 75th anniversary of the invention of the cyclotron by Ernest Orlando Lawrence at the University of California at Berkeley. Lawrence conceived the idea of the cyclotron early in 1929 after reading an article by Rolf Wideroe on high-energy accelerators. In the spring of 1930 one of his students, Nels Edlefsen, constructed two crude models of a cyclotron. Later in the fall of the same year, another student, M. Stanley Livingston

Mitigating the effect of optical back-scatter in multispectral underwater imaging

International Nuclear Information System (INIS)

Mortazavi, Halleh; Oakley, John P; Barkat, Braham

2013-01-01

Multispectral imaging is a very useful technique for extracting information from the underwater world. However, optical back-scatter changes the intensity value in each spectral band and this distorts the estimated spectrum. In this work, a filter is used to detect the level of optical back-scatter in each spectral band from a set of multispectral images. Extraction of underwater object spectra can be done by subtracting the estimated level of optical back-scatter and scaling the remainder in each spectral band from the captured image in the corresponding band. An experiment has been designed to show the performance of the proposed filter for correcting the set of multispectral underwater images and recovering the pixel spectra. The multispectral images are captured by a B/W CCD digital camera with a fast tunable liquid-crystal filter in 33 narrow spectral bands in clear and different levels of turbid water. Reference estimates for the optical back-scatter spectra are found by comparing a clear and a degraded set of multispectral images. The accuracy and consistency of the proposed method, the extended Oakley–Bu cost function, is examined by comparing the estimated values with the reference level of an optical back-scatter spectrum. The same comparison is made for the simple estimation approach. The results show that the simple method is not reliable and fail to estimate the level of optical back-scatter spectrum accurately. The results from processing experimental images in turbid water show that the effect of optical back-scatter can be mitigated in the image of each spectral band and, as a result, the spectra of the object can be recovered. However, for a very high level of turbid water the recovery is limited because of the effect of extinction. (paper)

Effect of thermal annealing on optical properties of implanted GaAs

NARCIS (Netherlands)

Kulik, M; Komarov, FF; Maczka, D

GaAs samples doped with indium atoms by ion implantation and thermal annealed were studied using a channelling method, Rutherford backscattering, and an ellipsometry. From these measurements it was observed that the layer implanted with 3 x 10(16) cm(-2) indium dose was totally damaged and its

Analysis rbs of CdS thin films grown by cbd to different intensities of the magnetic field and temperature of the chemical bath

International Nuclear Information System (INIS)

Pedrero, E.; Vigil, O.

1999-01-01

Depth and composition of CdS thin films grown by chemical bath deposition under different temperature and magnetic DC field conditions, were determined by Rutherford Backscattering Spectrometry. The above parameters were evaluated as a function of the bath temperature and the intensity of the induction magnetic field applied

High-fluence implantation of iron into polyimide

Czech Academy of Sciences Publication Activity Database

Macková, Anna; Hnatowicz, Vladimír; Peřina, Vratislav; Popok, V. N.; Khaibullin, R. I.; Bazarov, V. V.; Odzhaev, V. B.

158/159, - (2002), s. 395-398 ISSN 0257-8972 R&D Projects: GA ČR GA203/99/1626; GA ČR GA102/01/1324 Keywords : polyimide * ion implantation * iron * Rutherford backscattering spectroscopy Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.267, year: 2002

Instrumentation for PIXE and RBS

International Nuclear Information System (INIS)

2000-12-01

The purpose of this document is to give an overview of instrumentation for PIXE and Rutherford backscattering analysis, including hardware and software needed to perform the analysis, including detectors, analyzers, data acquisition systems and data analysis software. It also provides some information on accelerators needed for these applications

Electromagnetic ion cyclotron waves observed near the oxygen cyclotron frequency by ISEE 1 and 2

Science.gov (United States)

Fraser, B. J.; Samson, J. C.; Hu, Y. D.; Mcpherron, R. L.; Russell, C. T.

1992-01-01

The first results of observations of ion cyclotron waves by the elliptically orbiting ISEE 1 and 2 pair of spacecraft are reported. The most intense waves (8 nT) were observed in the outer plasmasphere where convection drift velocities were largest and the Alfven velocity was a minimum. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by cold plasma propagation theory are identified in the wave data. Computations of the experimental wave spectra during the passage through the plasmapause show that the spectral slots relate to the local plasma parameters, possibly suggesting an ion cyclotron wave growth source near the spacecraft. A regular wave packet structure seen over the first 30 min of the event is attributed to the modulation of this energy source by the Pc 5 waves seen at the same time.

Super-virtual Interferometric Separation and Enhancement of Back-scattered Surface Waves

KAUST Repository

Guo, Bowen; Hanafy, Sherif; Schuster, Gerard T.

2015-01-01

Back-scattered surface waves can be migrated to detect near-surface reflectors with steep dips. A robust surface-wave migration requires the prior separation of the back-scattered surface-wave events from the data. This separation is often difficult

The Ion Cyclotron, Lower Hybrid, and Alfven Wave Heating Methods

International Nuclear Information System (INIS)

Koch, R.

2004-01-01

This lecture covers the practical features and experimental results of the three heating methods. The emphasis is on ion cyclotron heating. First, we briefly come back to the main non-collisional heating mechanisms and to the particular features of the quasilinear coefficient in the ion cyclotron range of frequencies (ICRF). The specific case of the ion-ion hybrid resonance is treated, as well as the polarisation issue and minority heating scheme. The various ICRF scenarios are reviewed. The experimental applications of ion cyclotron resonance heating (ICRH) systems are outlined. Then, the lower hybrid and Alfven wave heating and current drive experimental results are covered more briefly. Where applicable, the prospects for ITER are commented

Stochasticity of the energy absorption in the electron cyclotron resonance

International Nuclear Information System (INIS)

Gutierrez T, C.; Hernandez A, O.

1998-01-01

The energy absorption mechanism in cyclotron resonance of the electrons is a present problem, since it could be considered from the stochastic point of view or this related with a non-homogeneous but periodical of plasma spatial structure. In this work using the Bogoliubov average method for a multi periodical system in presence of resonances, the drift equations were obtained in presence of a RF field for the case of electron cyclotron resonance until first order terms with respect to inverse of its cyclotron frequency. The absorbed energy equation is obtained on part of electrons in a simple model and by drift method. It is showed the stochastic character of the energy absorption. (Author)

Ion Cyclotron Heating on Proto-MPEX

Science.gov (United States)

Goulding, R. H.; Caughman, J. B. O.; Rapp, J.; Biewer, T. M.; Campbell, I. H.; Caneses, J. F.; Kafle, N.; Ray, H. B.; Showers, M. A.; Piotrowicz, P. A.

2016-10-01

Ion cyclotron heating will be used on Proto-MPEX (Prototype Material Plasma Exposure eXperiment) to increase heat flux to the target, to produce varying ion energies without substrate biasing, and to vary the extent of the magnetic pre-sheath for the case of a tilted target. A 25 cm long, 9 cm diameter dual half-turn helical ion cyclotron antenna has been installed in the device located at the magnetic field maximum. It couples power to ions via single pass damping of the slow wave at the fundamental resonance, and operates with ω 0.8ωci at the antenna location. It is designed to operate at power levels up to 30 kW, with a later 200 kW upgrade planned. Near term experiments include measuring RF loading at low power as a function of frequency and antenna gap. The plasma is generated by a helicon plasma source that has achieved ne > 5 ×1019m-3 operating with deuterium, as measured downstream from the ion cyclotron antenna location. Measurements will be compared with 1-D and 2-D models of RF coupling. The latest results will be presented. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

Retrieving forest stand parameters from SAR backscatter data using a neural network trained by a canopy backscatter model

International Nuclear Information System (INIS)

Wang, Y.; Dong, D.

1997-01-01

It was possible to retrieve the stand mean dbh (tree trunk diameter at breast height) and stand density from the Jet Propulsion Laboratory (JPL) Airborne Synthetic Aperture Radar (AIRSAR) backscatter data by using threelayered perceptron neural networks (NNs). Two sets of NNs were trained by the Santa Barbara microwave canopy backscatter model. One set of the trained NNs was used to retrieve the stand mean dbh, and the other to retrieve the stand density. Each set of the NNs consisted of seven individual NNs for all possible combinations of one, two, and three radar wavelengths. Ground and multiple wavelength AIRSAR backscatter data from two ponderosa pine forest stands near Mt. Shasta, California (U.S.A.) were used to evaluate the accuracy of the retrievals. The r.m.s. and relative errors of the retrieval for stand mean dbh were 6.1 cm and 15.6 per cent for one stand (St2), and 3.1 cm and 6.7 per cent for the other stand (St11). The r.m.s. and relative errors of the retrieval for stand density were 71.2 treesha-1 and 23.0 per cent for St2, and 49.7 treesha-1 and 21.3 per cent for St11. (author)

Calculations for the design and modification of the 2 cyclotrons of S.A.R.A

International Nuclear Information System (INIS)

Albrand, P.S.; Belmont, J.L.; Ripouteau, F.

1983-09-01

S.A.R.A. is a heavy ion accelerator constituted by 2 cyclotrons. The second cyclotron (post-accelerator) was entirely calculated at the I.S.N. The pole tips of the first cyclotron which is much older, have recently been modified. An almost identical procedure was used for the calculation of each element of the post-accelerator of S.A.R.A. and also for the modifications to the first cyclotron

Cyclotron Lines in Accreting Neutron Star Spectra

Science.gov (United States)

Wilms, Jörn; Schönherr, Gabriele; Schmid, Julia; Dauser, Thomas; Kreykenbohm, Ingo

2009-05-01

Cyclotron lines are formed through transitions of electrons between discrete Landau levels in the accretion columns of accreting neutron stars with strong (1012 G) magnetic fields. We summarize recent results on the formation of the spectral continuum of such systems, describe recent advances in the modeling of the lines based on a modification of the commonly used Monte Carlo approach, and discuss new results on the dependence of the measured cyclotron line energy from the luminosity of transient neutron star systems. Finally, we show that Simbol-X will be ideally suited to build and improve the observational database of accreting and strongly magnetized neutron stars.

Use of cyclotrons in medical research: Past, present, future

Science.gov (United States)

Smathers, James B.; Myers, Lee T.

1985-05-01

The use of cyclotrons in medical research started in the late 1930s with the most prominent use being neutron irradiation in cancer therapy. Due to a lack of understanding of the biological effect of neutrons, the results were less than encouraging. In the 1940s and 1950s, small cyclotrons were used for isotope production and in the mid 60s, the biological effect of neutrons was more thoroughly studied, with the result that a second trial of neutron therapy was initiated at Hammersmith Hospital, England. Concurrent with this, work on the use of high energy charged particles, initially protons and alphas, was initiated in Sweden and Russia and at Harvard and Berkeley. The English success in neutron therapy led to some pilot studies in the USA using physics cyclotrons of various energies and targets. These results in turn lead to the present series of machines presently being installed at M.D. Anderson Hospital (42 MeV), Seattle (50 MeV) and UCLA (46 MeV). The future probably bodes well for cyclotrons at the two extremes of the energy range. For nuclear medicine the shift is away from the use of multiple isotopes, which requires a large range of particles and energies to 11C, 13N, 15O, and 18F, which can be incorporated in metabolic specific compounds and be made with small 8-10 MeV p+ "table top" cyclotrons. For tumor therapy machines of 60 MeV or so will probably be the choice for the future, as they allow the treatment of deep seated tumors with neutrons and the charged particles have sufficient range to allow the treatment of ocular tumors.

Resonance cones below the ion cyclotron frequency: theory and experiment

International Nuclear Information System (INIS)

Bellan, P.

1976-03-01

The resonance cones existing below the ion cyclotron frequency, ω/sub c/sub i//, are shown, theoretically and experimentally, to be the asymptotes of hyperbolic constant-phase surfaces of low-frequency ion acoustic waves. Above ω/sub c/sub i// the surfaces transform into ellipses that are related to the electrostatic ion cyclotron waves and ion acoustic waves

Compositional Signatures in Acoustic Backscatter Over Vegetated and Unvegetated Mixed Sand-Gravel Riverbeds

Science.gov (United States)

Buscombe, D.; Grams, P. E.; Kaplinski, M. A.

2017-10-01

Multibeam acoustic backscatter has considerable utility for remote characterization of spatially heterogeneous bed sediment composition over vegetated and unvegetated riverbeds of mixed sand and gravel. However, the use of high-frequency, decimeter-resolution acoustic backscatter for sediment classification in shallow water is hampered by significant topographic contamination of the signal. In mixed sand-gravel riverbeds, changes in the abiotic composition of sediment (such as homogeneous sand to homogeneous gravel) tend to occur over larger spatial scales than is characteristic of small-scale bedform topography (ripples, dunes, and bars) or biota (such as vascular plants and periphyton). A two-stage method is proposed to filter out the morphological contributions to acoustic backscatter. First, the residual supragrain-scale topographic effects in acoustic backscatter with small instantaneous insonified areas, caused by ambiguity in the local (beam-to-beam) bed-sonar geometry, are removed. Then, coherent scales between high-resolution topography and backscatter are identified using cospectra, which are used to design a frequency domain filter that decomposes backscatter into the (unwanted) high-pass component associated with bedform topography (ripples, dunes, and sand waves) and vegetation, and the (desired) low-frequency component associated with the composition of sediment patches superimposed on the topography. This process strengthens relationships between backscatter and sediment composition. A probabilistic framework is presented for classifying vegetated and unvegetated substrates based on acoustic backscatter at decimeter resolution. This capability is demonstrated using data collected from diverse settings within a 386 km reach of a canyon river whose bed varies among sand, gravel, cobbles, boulders, and submerged vegetation.

Compositional signatures in acoustic backscatter over vegetated and unvegetated mixed sand-gravel riverbeds

Science.gov (United States)

Buscombe, Daniel; Grams, Paul E.; Kaplinski, Matt A.

2017-01-01

Multibeam acoustic backscatter has considerable utility for remote characterization of spatially heterogeneous bed sediment composition over vegetated and unvegetated riverbeds of mixed sand and gravel. However, the use of high-frequency, decimeter-resolution acoustic backscatter for sediment classification in shallow water is hampered by significant topographic contamination of the signal. In mixed sand-gravel riverbeds, changes in the abiotic composition of sediment (such as homogeneous sand to homogeneous gravel) tend to occur over larger spatial scales than is characteristic of small-scale bedform topography (ripples, dunes, and bars) or biota (such as vascular plants and periphyton). A two-stage method is proposed to filter out the morphological contributions to acoustic backscatter. First, the residual supragrain-scale topographic effects in acoustic backscatter with small instantaneous insonified areas, caused by ambiguity in the local (beam-to-beam) bed-sonar geometry, are removed. Then, coherent scales between high-resolution topography and backscatter are identified using cospectra, which are used to design a frequency domain filter that decomposes backscatter into the (unwanted) high-pass component associated with bedform topography (ripples, dunes, and sand waves) and vegetation, and the (desired) low-frequency component associated with the composition of sediment patches superimposed on the topography. This process strengthens relationships between backscatter and sediment composition. A probabilistic framework is presented for classifying vegetated and unvegetated substrates based on acoustic backscatter at decimeter resolution. This capability is demonstrated using data collected from diverse settings within a 386 km reach of a canyon river whose bed varies among sand, gravel, cobbles, boulders, and submerged vegetation.

Backscatter, anisotropy, and polarization of solar hard X-rays

International Nuclear Information System (INIS)

Bai, T.; Ramaty, R.

1978-01-01

Hard X-rays incident upon the photosphere with energies > or approx. =15 keV have high probabilities of backscatter due to Compton collisions with electrons. This effect has a strong influence on the spectrum, intensity, and polarization of solar hard X-rays - especially for anisotropic models in which the primary X-rays are emitted predominantly toward the photosphere. We have carried out a detailed study of X-ray backscatter, and we have investigated the interrelated problems of anisotropy, polarization, center-to-limb variation of the X-ray spectrum, and Compton backscatter in a coherent fashion. The results of this study are compared with observational data. Because of the large contribution from backscatter, for an anisotropic primary X-ray source which is due to bremsstrahlung of accelerated electrons moving predominantly down toward the photosphere, the observed X-ray flux around 30 keV does not depend significantly on the position of flare on the Sun. For such an anisotropic source, the X-ray spectrum observed in the 15-50 keV range becomes steeper with the increasing heliocentric angle of the flare. These results are compatible with the data. The degree of polarization of the sum of the primary and reflected X-rays with energies between about 15 and 30 keV can be very large for anisotropic primary X-ray sources, but it is less than about 4% for isotropic sources. We also discuss the characteristics of the brightness distribution of the X-ray albedo patch created by the Compton backscatter. The height and anisotropy of the primary hard X-ray source might be inferred from the study of the albedo patch

Electron Cyclotron Resonance Heating of a High-Density Plasma

DEFF Research Database (Denmark)

Hansen, F. Ramskov

1986-01-01

Various schemes for electron cyclotron resonance heating of tokamak plasmas with the ratio of electron plasma frequency to electron cyclotron frequency, "»pe/^ce* larger than 1 on axis, are investigated. In particular, a mode conversion scheme is investigated using ordinary waves at the fundamental...... of the electron cyclotron frequency. These are injected obliquely from the outside of the tokamak near an optimal angle to the magnetic field lines. This method involves two mode conversions. The ordinary waves are converted into extraordinary waves near the plasma cut-off layer. The extraordinary waves...... are subsequently converted into electrostatic electron Bernstein waves at the upper hybrid resonance layer, and the Bernstein waves are completely absorbed close to the plasma centre. Results are presented from ray-tracinq calculations in full three-dimensional geometry using the dispersion function for a hot non...

Isochronous variable energy cyclotron of IPEN-CNEN/SP (Brazil)

International Nuclear Information System (INIS)

Lucki, G.; Zanchetta, A.A.; Gouveia, S.; Klein, H.

1984-01-01

The cyclotron CV-28 installed at the Radiation Damage Division of IPEN-CNEN/SP is a multi-particle radiation source where protons, deuterons, 3 He ions and alpha particles can be accelerated with variable energy up to 24, 14, 36 and 28 MeV, respectively. The cyclotron is a versatile machine that can be applied in research and development of : radioisotope production - materials science - nuclear physics - activation analysis and others. First internal beam with 24 MeV protons has been obtained in April 23, 1981. First irradiation of Cu sample, at the external beam (beam current 1.5 μA), with 28 MeV alpha particles was performed in December 29, 1983. Main characteristics of the cyclotron are given together with a description of peripheral systems and experimental capability. Presently the accelerator is being optimized for cpontinuous running. (Author) [pt

Reduction of the beam pulse repetition rate of the Hamburg Isochronous Cyclotron

Energy Technology Data Exchange (ETDEWEB)

Krause, H; Langkau, R; Schirm, N [Hamburg Univ. (F.R. Germany). 1. Inst. fuer Experimentalphysik

1976-04-01

A system for the reduction of the beam pulse repetition rate of the energy-variable Hamburg Isochronous Cyclotron comprising beam pulse supression in the cyclotron center and in the external beam is described.

The relationship between VHF radar auroral backscatter amplitude and Doppler velocity: a statistical study

Directory of Open Access Journals (Sweden)

B. A. Shand

Full Text Available A statistical investigation of the relationship between VHF radar auroral backscatter intensity and Doppler velocity has been undertaken with data collected from 8 years operation of the Wick site of the Sweden And Britain Radar-auroral Experiment (SABRE. The results indicate three different regimes within the statistical data set; firstly, for Doppler velocities <200 m s^–1, the backscatter intensity (measured in decibels remains relatively constant. Secondly, a linear relationship is observed between the backscatter intensity (in decibels and Doppler velocity for velocities between 200 m s^–1 and 700 m s^–1. At velocities greater than 700 m s^–1 the backscatter intensity saturates at a maximum value as the Doppler velocity increases. There are three possible geophysical mechanisms for the saturation in the backscatter intensity at high phase speeds: a saturation in the irregularity turbulence level, a maximisation of the scattering volume, and a modification of the local ambient electron density. There is also a difference in the dependence of the backscatter intensity on Doppler velocity for the flow towards and away from the radar. The results for flow towards the radar exhibit a consistent relationship between backscatter intensity and measured velocities throughout the solar cycle. For flow away from the radar, however, the relationship between backscatter intensity and Doppler velocity varies during the solar cycle. The geometry of the SABRE system ensures that flow towards the radar is predominantly associated with the eastward electrojet, and flow away is associated with the westward electrojet. The difference in the backscatter intensity variation as a function of Doppler velocity is attributed to asymmetries between the eastward and westward electrojets and the geophysical parameters controlling the backscatter amplitude.

The relationship between VHF radar auroral backscatter amplitude and Doppler velocity: a statistical study

Directory of Open Access Journals (Sweden)

B. A. Shand

1996-08-01

Full Text Available A statistical investigation of the relationship between VHF radar auroral backscatter intensity and Doppler velocity has been undertaken with data collected from 8 years operation of the Wick site of the Sweden And Britain Radar-auroral Experiment (SABRE. The results indicate three different regimes within the statistical data set; firstly, for Doppler velocities <200 m s–1, the backscatter intensity (measured in decibels remains relatively constant. Secondly, a linear relationship is observed between the backscatter intensity (in decibels and Doppler velocity for velocities between 200 m s–1 and 700 m s–1. At velocities greater than 700 m s–1 the backscatter intensity saturates at a maximum value as the Doppler velocity increases. There are three possible geophysical mechanisms for the saturation in the backscatter intensity at high phase speeds: a saturation in the irregularity turbulence level, a maximisation of the scattering volume, and a modification of the local ambient electron density. There is also a difference in the dependence of the backscatter intensity on Doppler velocity for the flow towards and away from the radar. The results for flow towards the radar exhibit a consistent relationship between backscatter intensity and measured velocities throughout the solar cycle. For flow away from the radar, however, the relationship between backscatter intensity and Doppler velocity varies during the solar cycle. The geometry of the SABRE system ensures that flow towards the radar is predominantly associated with the eastward electrojet, and flow away is associated with the westward electrojet. The difference in the backscatter intensity variation as a function of Doppler velocity is attributed to asymmetries between the eastward and westward electrojets and the geophysical parameters controlling the backscatter amplitude.

Ultrasonic characterization of cancellous bone using apparent integrated backscatter

Energy Technology Data Exchange (ETDEWEB)

Hoffmeister, B K [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); III, C I Jones [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); Caldwell, G J [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); Kaste, S C [Department of Diagnostic Imaging, St Jude Children' s Research Hospital, Memphis, TN 38105 (United States)

2006-06-07

Apparent integrated backscatter (AIB) is a measure of the frequency-averaged (integrated) backscattered power contained in some portion of a backscattered ultrasonic signal. AIB has been used extensively to study soft tissues, but its usefulness as a tissue characterization technique for cancellous bone has not been demonstrated. To address this, we performed measurements on 17 specimens of cancellous bone over two different frequency ranges using a 1 MHz and 5 MHz broadband ultrasonic transducer. Specimens were obtained from bovine tibiae and prepared in the shape of cubes (15 mm side length) with faces oriented along transverse (anterior, posterior, medial and lateral) and longitudinal (superior and inferior) principal anatomic directions. A mechanical scanning system was used to acquire multiple backscatter signals from each direction for each cube. AIB demonstrated highly significant linear correlations with bone mineral density (BMD) for both the transverse (R{sup 2} = 0.817) and longitudinal (R{sup 2} = 0.488) directions using the 5 MHz transducer. In contrast, the correlations with density were much weaker for the 1 MHz transducer (R{sup 2} = 0.007 transverse, R{sup 2} = 0.228 longitudinal). In all cases where a significant correlation was observed, AIB was found to decrease with increasing BMD.

ROKCY-12 (KCCH PET-dedicated cyclotron): main features and improvements

International Nuclear Information System (INIS)

Chai, J. S.; Kim, Y. S.; Yang, Y. T.; Jung, I. S.; Hong, S. S.; Lee, M. Y.; Jang, H. S.; Kim, J. H.

2002-01-01

In this paper, we describe the development of 13 MeV cyclotron (ROKCY-12) that can be used for a Position Emission Tomography(PET) purpose. This cyclotron with a maximum beam energy of 13 MeV can produce radio isotopes especially 18 F which has a relatively short half lifetime of 110 minutes. First, we show the beam characteristics can be used to carry out the operation of ROCKY-12. Based on this, a computer program has been developed to determine main cyclotron parameters such as cyclotron magnet, RF system, ion source, vacuum system and other cyclotron operation parameters. And then we show the result of design and manufacturing feature of ROKCY-12. By using this design program, one can determines magnet yoke geometry and the average magnetic fields etc. And then the three-dimensional computer program OPERA-3D has been invoked to determine magnet pole tips. Validity of the design can be seen by investigating magnetic fields, radial and vertical focusing frequencies as a function of the beam energy. In this paper, we show the results of cyclotron beam by ROCKY-12. We designed 77.3 MHz RF system and ion source system. We tested RF resonance each coupling methods. We show the result of RF design and prototype operation. Developed ion source is PIG type. We described our design methods and implementation. We report the result of getting negative hydrogen ion. Cyclotron controller asks inputs of every sensor and output of every instrument for notifying current condition to operator. It has independent controllers, for example DC power supply, vacuum system, beam profile system, beam extraction system, RF system, ion source, cooling unit and so on. Basically, each control system uses RS-485 for communication to main control computer. Consumers reward products and services that feature quality, originality, a distinct personality and charm. The International Standardization Organization (ISO) requires, as its mission, that we achieve competitive superiority by

Superconducting conversion of the Oak Ridge Isochronous Cyclotron

International Nuclear Information System (INIS)

Martin, J.A.; Ball, J.B.; Cleary, E.D.

1981-01-01

The superconducting conversion of the Oak Ridge Isochronous Cyclotron (ORIC) will replace the existing aluminum main magnet coils with a NbTi superconducting coil system to provide an increase in magnetic field from 1.9 to 3.3 T. The higher magnetic field will provide a three-fold increase in maximum energy capability of the cyclotron for high mass ions. The conversion will include a new beam extraction system, magnet yoke stiffening to counteract the increased magnetic forces, and minor modifications to the beam transport systems and shielding

Solid targets for production of radioisotopes with cyclotron

International Nuclear Information System (INIS)

Paredes G, L.; Balcazar G, M.

1999-01-01

The design of targets for production of radioisotopes and radiopharmaceuticals of cyclotron to medical applications requires a detailed analysis of several variables such as: cyclotron operation conditions, choice of used materials as target and their physicochemical characteristics, activity calculation, the yielding of each radioisotope by irradiation, the competition of nuclear reactions in function of the projectiles energy and the collision processes amongst others. The objective of this work is to determine the equations for the calculation for yielding of solid targets at the end of the proton irradiation. (Author)

Operational health and physics service during the maintenance of the Australian National Medical Cyclotron

International Nuclear Information System (INIS)

Mukherjee, B.

1994-01-01

Modern Medical Cyclotrons use intense beams of high energy protons or deuterons to produce large activities of short and medium lived radionuclides. After continuous operation for prolonged periods the Cyclotron components become activated through various nuclear interactions therefore, the risk of personal radiation hazard while handling such activated cyclotron components is high. This paper describes all operational aspects of the Health Physics service evolved during the first preventative maintenance program of the Australian National Medical Cyclotron, which took place in June 1993. 5 refs., 3 tabs., 2 figs

Effects of Biota on Backscatter: Experiments with the Portable Acoustic Laboratory (PAL)

National Research Council Canada - National Science Library

Jones, Christopher

2003-01-01

.... Monitoring showed a sudden drop in backscatter, but this was short lived. Abundant mysid shrimp appeared to have caused microtopographic changes that quickly raised backscatter intensity to near-background levels...

Wave trajectory and electron cyclotron heating in toroidal plasmas

International Nuclear Information System (INIS)

Maekawa, T.; Tanaka, S.; Terumichi, Y.; Hamada, Y.

1977-12-01

Wave trajectories propagating obliquely to magnetic field in toroidal plasmas are studied theoretically. Results show that the ordinary wave at appropriate incident angle is mode-converted to the extraordinary wave at first turning point and is further converted to the electron Bernstein wave during passing a loop or a hooked nail curve near second turning point and is cyclotron-damped away, resulting in local electron heating, before arriving at cyclotron resonance layer. (auth.)

Study of multiple scattering effects in heavy ion RBS

Energy Technology Data Exchange (ETDEWEB)

Fang, Z.; O`Connor, D.J. [Newcastle Univ., NSW (Australia). Dept. of Physics

1996-12-31

Multiple scattering effect is normally neglected in conventional Rutherford Backscattering (RBS) analysis. The backscattered particle yield normally agrees well with the theory based on the single scattering model. However, when heavy incident ions are used such as in heavy ion Rutherford backscattering (HIRBS), or the incident ion energy is reduced, multiple scattering effect starts to play a role in the analysis. In this paper, the experimental data of 6MeV C ions backscattered from a Au target are presented. In measured time of flight spectrum a small step in front of the Au high energy edge is observed. The high energy edge of the step is about 3.4 ns ahead of the Au signal which corresponds to an energy {approx} 300 keV higher than the 135 degree single scattering energy. This value coincides with the double scattering energy of C ion undergoes two consecutive 67.5 degree scattering. Efforts made to investigate the origin of the high energy step observed lead to an Monte Carlo simulation aimed to reproduce the experimental spectrum on computer. As a large angle scattering event is a rare event, two consecutive large angle scattering is extremely hard to reproduce in a random simulation process. Thus, the simulation has not found a particle scattering into 130-140 deg with an energy higher than the single scattering energy. Obviously faster algorithms and a better physical model are necessary for a successful simulation. 16 refs., 3 figs.

Study of multiple scattering effects in heavy ion RBS

Energy Technology Data Exchange (ETDEWEB)

Fang, Z; O` Connor, D J [Newcastle Univ., NSW (Australia). Dept. of Physics

1997-12-31

Multiple scattering effect is normally neglected in conventional Rutherford Backscattering (RBS) analysis. The backscattered particle yield normally agrees well with the theory based on the single scattering model. However, when heavy incident ions are used such as in heavy ion Rutherford backscattering (HIRBS), or the incident ion energy is reduced, multiple scattering effect starts to play a role in the analysis. In this paper, the experimental data of 6MeV C ions backscattered from a Au target are presented. In measured time of flight spectrum a small step in front of the Au high energy edge is observed. The high energy edge of the step is about 3.4 ns ahead of the Au signal which corresponds to an energy {approx} 300 keV higher than the 135 degree single scattering energy. This value coincides with the double scattering energy of C ion undergoes two consecutive 67.5 degree scattering. Efforts made to investigate the origin of the high energy step observed lead to an Monte Carlo simulation aimed to reproduce the experimental spectrum on computer. As a large angle scattering event is a rare event, two consecutive large angle scattering is extremely hard to reproduce in a random simulation process. Thus, the simulation has not found a particle scattering into 130-140 deg with an energy higher than the single scattering energy. Obviously faster algorithms and a better physical model are necessary for a successful simulation. 16 refs., 3 figs.

Electron cyclotron power management for control of neoclassical tearing modes in the ITER baseline scenario

Science.gov (United States)

Poli, F. M.; Fredrickson, E. D.; Henderson, M. A.; Kim, S.-H.; Bertelli, N.; Poli, E.; Farina, D.; Figini, L.

2018-01-01

Time-dependent simulations are used to evolve plasma discharges in combination with a modified Rutherford equation for calculation of neoclassical tearing mode (NTM) stability in response to electron cyclotron (EC) feedback control in ITER. The main application of this integrated approach is to support the development of control algorithms by analyzing the plasma response with physics-based models and to assess how uncertainties in the detection of the magnetic island and in the EC alignment affect the ability of the ITER EC system to fulfill its purpose. Simulations indicate that it is critical to detect the island as soon as possible, before its size exceeds the EC deposition width, and that maintaining alignment with the rational surface within half of the EC deposition width is needed for stabilization and suppression of the modes, especially in the case of modes with helicity (2, 1) . A broadening of the deposition profile, for example due to wave scattering by turbulence fluctuations or not well aligned beams, could even be favorable in the case of the (2, 1)- NTM, by relaxing an over-focussing of the EC beam and improving the stabilization at the mode onset. Pre-emptive control reduces the power needed for suppression and stabilization in the ITER baseline discharge to a maximum of 5 MW, which should be reserved and available to the upper launcher during the entire flattop phase. Assuming continuous triggering of NTMs, with pre-emptive control ITER would be still able to demonstrate a fusion gain of Q=10 .

Correlation and uncertainties evaluation in backscattering of entrance surface air kerma measurements

Energy Technology Data Exchange (ETDEWEB)

Teixeira, G.J.; Sousa, C.H.S.; Peixoto, J.G.P., E-mail: gt@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

The air kerma measurement is important to verify the applied doses in radiodiagnostic. The literature determines some methods to measure the entrance surface air kerma or entrance surface dose but some of this methods may increase the measurement with the backscattering. Were done setups of measurements to do correlations between them. The expanded uncertainty exceeded 5% for measurements with backscattering, reaching 8.36%, while in situations where the backscattering was avoided, the uncertainty was 3.43%. (author)

Development of scaling rules for Rutherford type superconducting cables

International Nuclear Information System (INIS)

Royet, J.M.; Scanlan, R.M.

1991-01-01

During the R and D phase of the Superconducting Supercollider (SSC) program, LBL was responsible for establishing the parameters for cables used in SSC dipole and quadrupole magnets. In addition, LBL has collaborated with Fermi National Accelerator Laboratory on the design and fabrication of a new cable for use in the Low Beta Quadrupoles. As a result of the development work on these and other cables, we have arrived a set of scaling rules which provide guidelines for choosing the parameters for a wide range of superconducting cables. These parameters include strand size, strand number, keystone angle, percent compaction, cable pitch and compacted cable dimensions. In addition, we have defined the tolerance ranges for the key cable manufacturing parameters such as mandrel size and shape, strand tension, and Turkshead temperature control. In this paper, the authors present the results on cables ranging from 8 strands to 36 strands of 0.65mm wire and from 8 strands to 30 strands of 0.8mm wire. The authors use these results to demonstrate the application of the scaling rules for Rutherford-type cable