WorldWideScience

Sample records for electron magnetic spectrometer

  1. MAGNETIC SPECTROMETER DESIGN FOR ELECTRON SCATTERING ABOVE 1 Bev

    Energy Technology Data Exchange (ETDEWEB)

    Schopper, H.

    1963-06-15

    Design considerations are discussed for magnetic spectrometer electron scattering investigations with the higher energy (above 1 Bev) electron sources which are being developed. The spectrometers are to be used to discriminate between elastic and inelastic processes. A momentum resolution of the order of one per cent is required for these experiments. Various spectrometers are compared according to their optical properties and the number of magnets they consist of. (R.E.U.)

  2. Large acceptance magnetic spectrometers for polarized deep inelastic electron scattering

    International Nuclear Information System (INIS)

    Petratos, G.G.; Eisele, R.L.; Gearhart, R.A.; Hughes, E.W.; Young, C.C.

    1991-10-01

    The design of two magnetic spectrometers for the measurement of the spin-dependent structure function g 1 n of the neutron and a test of the Bjorken sum rule is described. The measurement will consist of scattering 23 GeV polarized electrons off a polarized 3 He target and detecting scattered electrons of 7 to 18 GeV at 4.5 degree and 7 degree. Each spectrometer is based on two large aperture dipole magnets bending in opposite directions. This ''reverse'' deflection design doubles the solid angle as compared to the conventional design of same direction bends used in previous experiments. Proper choice of the deflection angles and the distance between the two dipoles in each spectrometer allows background photons from radiative processes to reach the detectors only after at least two bounces off the spectrometer vacuum walls, resulting in an expected tolerable background. Each spectrometer is equipped with a pair of Cerenkov detectors, a pair of scintillation hodoscopes and a lead-glass shower calorimeter providing electron and pion identification with angular and momentum resolutions sufficient for the experimental measurement. 7 refs., 8 figs., 1 tab

  3. Permanent-magnet energy spectrometer for electron beams from radiotherapy accelerators

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, David J.; Shikhaliev, Polad M.; Matthews, Kenneth L. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Baton Rouge, Louisiana 70803-4001 (United States); Hogstrom, Kenneth R., E-mail: hogstrom@lsu.edu; Carver, Robert L.; Gibbons, John P. [Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, Louisiana 70809-3482 and Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Baton Rouge, Louisiana 70803-4001 (United States); Clarke, Taylor; Henderson, Alexander; Liang, Edison P. [Physics and Astronomy Department, Rice University, 6100 Main MS-61, Houston, Texas 77005-1827 (United States)

    2015-09-15

    Purpose: The purpose of this work was to adapt a lightweight, permanent magnet electron energy spectrometer for the measurement of energy spectra of therapeutic electron beams. Methods: An irradiation geometry and measurement technique were developed for an approximately 0.54-T, permanent dipole magnet spectrometer to produce suitable latent images on computed radiography (CR) phosphor strips. Dual-pinhole electron collimators created a 0.318-cm diameter, approximately parallel beam incident on the spectrometer and an appropriate dose rate at the image plane (CR strip location). X-ray background in the latent image, reduced by a 7.62-cm thick lead block between the pinhole collimators, was removed using a fitting technique. Theoretical energy-dependent detector response functions (DRFs) were used in an iterative technique to transform CR strip net mean dose profiles into energy spectra on central axis at the entrance to the spectrometer. These spectra were transformed to spectra at 95-cm source to collimator distance (SCD) by correcting for the energy dependence of electron scatter. The spectrometer was calibrated by comparing peak mean positions in the net mean dose profiles, initially to peak mean energies determined from the practical range of central-axis percent depth-dose (%DD) curves, and then to peak mean energies that accounted for how the collimation modified the energy spectra (recalibration). The utility of the spectrometer was demonstrated by measuring the energy spectra for the seven electron beams (7–20 MeV) of an Elekta Infinity radiotherapy accelerator. Results: Plots of DRF illustrated their dependence on energy and position in the imaging plane. Approximately 15 iterations solved for the energy spectra at the spectrometer entrance from the measured net mean dose profiles. Transforming those spectra into ones at 95-cm SCD increased the low energy tail of the spectra, while correspondingly decreasing the peaks and shifting them to slightly lower

  4. Permanent-magnet energy spectrometer for electron beams from radiotherapy accelerators.

    Science.gov (United States)

    McLaughlin, David J; Hogstrom, Kenneth R; Carver, Robert L; Gibbons, John P; Shikhaliev, Polad M; Matthews, Kenneth L; Clarke, Taylor; Henderson, Alexander; Liang, Edison P

    2015-09-01

    The purpose of this work was to adapt a lightweight, permanent magnet electron energy spectrometer for the measurement of energy spectra of therapeutic electron beams. An irradiation geometry and measurement technique were developed for an approximately 0.54-T, permanent dipole magnet spectrometer to produce suitable latent images on computed radiography (CR) phosphor strips. Dual-pinhole electron collimators created a 0.318-cm diameter, approximately parallel beam incident on the spectrometer and an appropriate dose rate at the image plane (CR strip location). X-ray background in the latent image, reduced by a 7.62-cm thick lead block between the pinhole collimators, was removed using a fitting technique. Theoretical energy-dependent detector response functions (DRFs) were used in an iterative technique to transform CR strip net mean dose profiles into energy spectra on central axis at the entrance to the spectrometer. These spectra were transformed to spectra at 95-cm source to collimator distance (SCD) by correcting for the energy dependence of electron scatter. The spectrometer was calibrated by comparing peak mean positions in the net mean dose profiles, initially to peak mean energies determined from the practical range of central-axis percent depth-dose (%DD) curves, and then to peak mean energies that accounted for how the collimation modified the energy spectra (recalibration). The utility of the spectrometer was demonstrated by measuring the energy spectra for the seven electron beams (7-20 MeV) of an Elekta Infinity radiotherapy accelerator. Plots of DRF illustrated their dependence on energy and position in the imaging plane. Approximately 15 iterations solved for the energy spectra at the spectrometer entrance from the measured net mean dose profiles. Transforming those spectra into ones at 95-cm SCD increased the low energy tail of the spectra, while correspondingly decreasing the peaks and shifting them to slightly lower energies. Energy calibration

  5. A magnetic-lens - mini-orange coincidence spectrometer

    International Nuclear Information System (INIS)

    Bargholtz, C.; Holmberg, L.; Ruus, N.; Tegner, P.E.; Weiss, G.

    1997-04-01

    A coincidence spectrometer consisting of a Gerholm type magnetic lens and a permanent magnet mini-orange spectrometer is described. Electron-electron or electron-positron coincidences may be registered in various angular settings. The spectrometer has been developed mainly to search for anomalous contributions to Bhabha scattering or positrons and is at present used for such studies. 6 refs

  6. APES: Acute Precipitating Electron Spectrometer - A High Time Resolution Monodirectional Magnetic Deflection Electron Spectrometer

    Science.gov (United States)

    Michell, R. G.; Samara, M.; Grubbs, G., II; Ogasawara, K.; Miller, G.; Trevino, J. A.; Webster, J.; Stange, J.

    2016-01-01

    We present a description of the Acute Precipitating Electron Spectrometer (APES) that was designed and built for the Ground-to-Rocket Electron Electrodynamics Correlative Experiment (GREECE) auroral sounding rocket mission. The purpose was to measure the precipitating electron spectrum with high time resolution, on the order of milliseconds. The trade-off made in order to achieve high time resolution was to limit the aperture to only one look direction. The energy selection was done by using a permanent magnet to separate the incoming electrons, such that the different energies would fall onto different regions of the microchannel plate and therefore be detected by different anodes. A rectangular microchannel plate (MCP) was used (15 mm x 100 mm), and there was a total of 50 discrete anodes under the MCP, each one 15 mm x 1.5 mm, with a 0.5 mm spacing between anodes. The target energy range of APES was 200 eV to 30 keV.

  7. Magnetic field calculations for the technical proposal of the TESLA spectrometer magnet

    International Nuclear Information System (INIS)

    Morozov, N.A.; Schreiber, H.J.

    2003-01-01

    The TESLA electron-positron linear collider is under consideration at DESY (Hamburg). The realization of the physical program at this collider requires the knowledge of the beam energy of both beams (e + and e - ) with a precision of ΔE/E ≤ 10 -4 . The magnetic spectrometer was proposed as an energy measuring device. The report describes calculations for the preliminary conceptual design of this type of the spectrometer. The 2D calculations of the magnetic field for the spectrometer magnet have been performed by POISSON SUPERFISH computer code. The basic technical parameters of the magnet have been determined. These data will serve as a basis for the technical design of the spectrometer magnet and discuss its integration in the spectrometer

  8. A multichannel magnetic β-ray spectrometer for rapid measurements of electron spectra

    International Nuclear Information System (INIS)

    Kariya, Komyo; Morikawa, Kaoru.

    1989-01-01

    In order to make the magnetic β-ray spectrometer suitable for rapid measurements of electron spectra with short-lived nuclides, twelve small GM counters have been arrayed along the focal plane of a 180deg focusing flat type design. All the signal pulses from each one of these detectors are mixed together onto a single cable. By means of multichannel PHA, each pulse can be traced back to the specific detector which sent it out. In order to avoid time consuming evacuation procedures, the sample source is placed outside a thin window of the preevacuated analyzer chamber. By the use of this multichannel spectrometer a β-ray spectrum with maximum energy up to about 10 MeV can be measured within 1 min or so. Electron spectra measured with 113m In, 119m In and 144 Pr source are shown. (author)

  9. Beta-spectrometer with magnetic filter of mini orange type

    International Nuclear Information System (INIS)

    Gorozhankin, V.M.; Gromov, K.Ya.; Kalinnikov, V.G.; Sereeter, Z.; Fominykh, V.I.; Malikov, Sh.R.; Yuldashev, M.B.

    1997-01-01

    At the ISOL facility YASNAPP-2 a β-spectrometer with a magnetic filter of the miniorange type is constructed to measure γ-ray internal conversion coefficients. The magnetic filter of the mini orange type is an assemblage of permanent magnets creating a toroidal magnetic field perpendicular to the electron trajectories from the source to the Si(Li) detector. The chosen profile of the permanent magnets allowed electron registration in the defined energy energy interval with some transmission increase. There are two sets of permanent magnets of the different thickness. Varying the type and number of permanent magnets one can set the detected electron energy intervals in a 50-2500 keV range. The efficiency of the spectrometer was investigated for different assemblages of the mini orange magnet. The facility can be used for the e-γ coincidence investigation. (A.A.D.)

  10. Simulated performance of the in-beam conversion-electron spectrometer, SPICE

    Energy Technology Data Exchange (ETDEWEB)

    Ketelhut, S., E-mail: ketelhut@triumf.ca [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada); Evitts, L.J.; Garnsworthy, A.B.; Bolton, C.; Ball, G.C.; Churchman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada); Dunlop, R. [Department of Physics, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (Canada); Hackman, G.; Henderson, R.; Moukaddam, M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada); Rand, E.T.; Svensson, C.E. [Department of Physics, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (Canada); Witmer, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada)

    2014-07-01

    The SPICE spectrometer is a new in-beam electron spectrometer designed to operate in conjunction with the TIGRESS HPGe Clover array at TRIUMF-ISAC. The spectrometer consists of a large area, annular, segmented lithium-drifted silicon electron detector shielded from the target by a photon shield. A permanent magnetic lens directs electrons around the photon shield to the detector. Experiments will be performed utilising Coulomb excitation, inelastic-scattering, transfer and fusion–evaporation reactions using stable and radioactive ion beams with suitable heavy-ion detection. Good detection efficiency can be achieved in a large energy range up to 3500 keV electron energy using several magnetic lens designs which are quickly interchangeable. COMSOL and Geant4 simulations have been used to maximise the detection efficiency. In addition, the simulations have guided the design of components to minimise the contributions from various sources of backgrounds.

  11. A silicon strip detector used as a high rate focal plane sensor for electrons in a magnetic spectrometer

    CERN Document Server

    Miyoshi, T; Fujii, Y; Hashimoto, O; Hungerford, E V; Sato, Y; Sarsour, M; Takahashi, T; Tang, L; Ukai, M; Yamaguchi, H

    2003-01-01

    A silicon strip detector was developed as a focal plane sensor for a 300 MeV electron spectrometer and operated in a high rate environment. The detector with 500 mu m pitch provided good position resolution for electrons crossing the focal plane of the magnetic spectrometer system which was mounted in Hall C of the Thomas Jefferson National Accelerator Facility. The design of the silicon strip detector and the performance under high counting rate (<=2.0x10 sup 8 s sup - sup 1 for approx 1000 SSD channels) and high dose are discussed.

  12. Wide-aperture magnetic spectrometer with face position of MWPC

    International Nuclear Information System (INIS)

    Avakyan, R.O.; Avetisyan, A.Eh.; Ajvazyan, R.B.; Asaturyan, R.A.; Dallakyan, K.R.; Kizogyan, O.S.; Matevosyan, Eh.M.; Sukiasyan, Yu.Z.; Taroyan, S.P.

    1988-01-01

    A pair magnetic spectrometer with automated wire chambers for studying electron and positron interactions with monocrystals at the Erevan synchrotron is described. As a working gas the argon-methane mixture with methylal vapor addition is used. Results of modelling and experiments with spectrometer are presented. 2 refs.; 6 figs

  13. A 'tiny-orange' spectrometer for electrons

    International Nuclear Information System (INIS)

    Silva, N.C. da.

    1990-01-01

    An tiny-orange electron spectrometer was designed and constructed using flat permanent magnets and a surface barrier detector. The transmission functions of different system configurations were determined for energies in the 200-1100 KeV range. A mathematical model for the system was developed. (L.C.J.A.)

  14. SU-F-T-84: Measurement and Monte-Carlo Simulation of Electron Phase Spaces Using a Wide Angle Magnetic Electron Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Englbrecht, F; Lindner, F; Bin, J; Wislsperger, A; Reiner, M; Kamp, F; Belka, C; Dedes, G; Schreiber, J; Parodi, K [LMU Munich, Munich, Bavaria (Germany)

    2016-06-15

    Purpose: To measure and simulate well-defined electron spectra using a linear accelerator and a permanent-magnetic wide-angle spectrometer to test the performance of a novel reconstruction algorithm for retrieval of unknown electron-sources, in view of application to diagnostics of laser-driven particle acceleration. Methods: Six electron energies (6, 9, 12, 15, 18 and 21 MeV, 40cm × 40cm field-size) delivered by a Siemens Oncor linear accelerator were recorded using a permanent-magnetic wide-angle electron spectrometer (150mT) with a one dimensional slit (0.2mm × 5cm). Two dimensional maps representing beam-energy and entrance-position along the slit were measured using different scintillating screens, read by an online CMOS detector of high resolution (0.048mm × 0.048mm pixels) and large field of view (5cm × 10cm). Measured energy-slit position maps were compared to forward FLUKA simulations of electron transport through the spectrometer, starting from IAEA phase-spaces of the accelerator. The latter ones were validated against measured depth-dose and lateral profiles in water. Agreement of forward simulation and measurement was quantified in terms of position and shape of the signal distribution on the detector. Results: Measured depth-dose distributions and lateral profiles in the water phantom showed good agreement with forward simulations of IAEA phase-spaces, thus supporting usage of this simulation source in the study. Measured energy-slit position maps and those obtained by forward Monte-Carlo simulations showed satisfactory agreement in shape and position. Conclusion: Well-defined electron beams of known energy and shape will provide an ideal scenario to study the performance of a novel reconstruction algorithm using measured and simulated signal. Future work will increase the stability and convergence of the reconstruction-algorithm for unknown electron sources, towards final application to the electrons which drive the interaction of TW-class laser

  15. Workshop on CEBAF [Continuous Electron Beam Accelerator Facility] spectrometer magnet design and technology: Proceedings

    International Nuclear Information System (INIS)

    1986-09-01

    The planned experimental program at CEBAF includes high-resolution, large acceptance spectrometers and a large toroidal magnetic, detector. In order to take full advantage of the high quality beam characteristics, the performances required will make these devices quite unique instruments compared to existing facilities in the same energy range. Preliminary designs have shown that such performances can be reached, but key questions concerning design concepts and most appropriate and cost-effective technologies had to be answered before going further with the designs. It was the purpose of the Workshop on CEBAF Spectrometer Magnet Design and Technology, organized by the CEBAF Research and Engineering Divisions, to provide the most complete information about the state-of-the-art tools and techniques in magnet design and construction and to discuss the ones most appropriate to the CEBAF spectrometers. In addition, it is expected that this Workshop will be the staring point for further interactions and collaborations between international magnet experts and the CEBAF staff, during the whole process of designing and building the spectrometers

  16. Magnetic spectrometer Grand Raiden

    International Nuclear Information System (INIS)

    Fujiwara, M.; Akimune, H.; Daito, I.; Fujimura, H.; Fujita, Y.; Hatanaka, K.; Ikegami, H.; Katayama, I.; Nagayama, K.; Matsuoka, N.; Morinobu, S.; Noro, T.; Yoshimura, M.; Sakaguchi, H.; Sakemi, Y.; Tamii, A.; Yosoi, M.

    1999-01-01

    A high-resolution magnetic spectrometer called 'Grand Raiden' is operated at the RCNP ring cyclotron facility in Osaka for nuclear physics studies at intermediate energies. This magnetic spectrometer has excellent ion-optical properties. In the design of the spectrometer, the second-order dispersion matching condition has been taken into account, and almost all the aberration terms such as (x vertical bar θ 3 ), (x vertical bar θφ 2 ), (x vertical bar θ 2 δ) and (x vertical bar θδ 2 ) in a third-order matrix calculation are optimized. A large magnetic rigidity of the spectrometer (K = 1400 MeV) gives a great advantage to measure the charge-exchange ( 3 He, t) reactions at 450 MeV. The ability of the high-resolution measurement has been demonstrated. Various coincidence measurements are performed to study the nuclear structures of highly excited states through decay properties of nuclear levels following nuclear reactions at intermediate energies

  17. Design and performance estimates for the l'OASIS experiment magnetic spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Dugan, G.; Misuri, A.; Leemans, W.

    2001-11-19

    Two double-focusing magnetic specrometers will be used to momentum analyze the electron beam produced by the l'OASIS laser plasma wakefield accelerator. One spectrometer, based on a round pole magnet, has an operating range up to 50 MeV/c, with a resolution in the 1 - 2 percent range. The other spectrometer, based on a wedge dipole magnet, has better resolution (about 0.5 percent) but an operating range limited to below 18 MeV/c. This note describes the optical design of the spectrometers, and provides detailed estimates of performance features such as dynamic range, operating range, calibration, resolution, acceptance, and aberrations.

  18. Design of a pulsed angular selective electron gun for the KATRIN main spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Winzen, Daniel; Hannen, Volker; Ortjohann, Hans-Werner; Zacher, Michael; Weinheimer, Christian [Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet, Muenster (Germany); Collaboration: KATRIN-Collaboration

    2012-07-01

    The KATRIN (KArlsruhe TRItium Neutrino mass) experiment will study the tritium {beta}-spectrum near the endpoint of 18.6 keV, aiming to measure the mass of the electron antineutrino. Using an electrostatic retarding spectrometer (MAC-E-Filter), the projected sensitivity for m{sub ve} is 200 meV/c{sup 2} at 90% C.L. In order to map out the electric and magnetic fields in the main spectrometer, an angular selective electron gun is currently being developed. The e-gun uses an UV-Laser to produce electrons via the photo-electric effect from a copper substrate which are then accelerated electrostatically. It features a small energy spread of approx. 0.1 eV, a sharp emission angle and will be able to cover the whole magnetic flux tube of KATRIN. Using a pulsed laser it is also possible to investigate the time of flight (TOF) of electrons through the spectrometer, offering enhanced sensitivity to spectrometer properties far away from the analysing plane. By comparing information from transmission function measurements and TOF data with Monte Carlo simulations of the setup, one will be able to achieve a detailed understanding of the spectrometer properties.

  19. Resonant cell of a double nuclear electron resonance spectrometer for performance in a 120-350 Gs magnetic field

    International Nuclear Information System (INIS)

    Baldin, V.I.; Stepanov, A.P.

    1976-01-01

    Spectrometer double-frequency resonance cell construction of a double nuclear electron resonance for operation in 120-350 Gs magnetic fields is described. The cell has been developed from a special decimeter resonator with a concentrated capacitance. The electric and magnetic components of a high frequency field are efficiently divided in the separator. Therefore, the insertion of a measuring coil and a sample in the maximum of the magnetic component of the field does not practically affect the distribution and parameters of the high-frequency field. The double-frequency resonance cell proposed provides for a higher accuracy of measuring amplifications of the nuclear magnetic resonance signals when there is the overhauzer effect for 120-350 Gs magnetic fields

  20. Some conceptual designs for a LASSY spectrometer magnet

    International Nuclear Information System (INIS)

    Green, M.A.

    1995-09-01

    The LASSY spectrometer is a gas filled spectrometer (hydrogen or helium at a pressure of about 1 torr). The design bending power for the primary bending magnet for the spectrometer will have an induction bend radius product of 2.5 tesla-meters. In order to increase the acceptance of the spectrometer, the bending magnet system must be located close to the target where the desired nuclei are created. The spectrometer magnet system must consist of both bending and focusing elements so that the wide acceptance of particles can be brought to a focus at the analysis point that is down stream from the last magnet element. In order improve the spectrometer resolution and to catch the shortest lived nuclei, the length of the magnet system must be as short as possible. The length for the LASSY spectrometer magnet system from the target to the analysis point has been set at 2.5 meters or less. To improve the resolution of the spectrometer, the bending angle for bending magnet system must be increased to close to 180 degrees. In order to achieve a large bending angle and a short magnet system length, the bending induction must be above 3 tesla and the focusing elements must be combined with the bending elements. As a result, a LASSY spectrometer will have bending magnet with a bending angle from 140 to 170 degrees. This magnet win be combined with one or more focusing magnets (a straight dipole in some places and a combined function dipole in other places). The result is a single superconducting bending magnet with one or more quadrupoles incorporated within the large angle bending magnet

  1. The OPERA magnetic spectrometer

    CERN Document Server

    Ambrosio, M; Dusini, S; Dulach, B; Fanin, C; Felici, G; Corso, F D; Garfagnini, A; Grianti, F; Gustavino, C; Monacelli, P; Paoloni, A; Stanco, L; Spinetti, M; Terranova, F; Votano, L

    2004-01-01

    The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the lead-nuclear emulsion targets. The magnet is made up of two vertical walls of rectangular cross section connected by return yokes. The particle trajectories are measured by high precision drift tubes located before and after the arms of the magnet. Moreover, the magnet steel is instrumented with Resistive Plate Chambers that ease pattern recognition and allow a calorimetric measurement of the hadronic showers. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained from the magnet and RPC prototypes and the installation of the final apparatus at the Gran Sasso laboratories. We discuss the mechanical and magnetic properties of the steel and the techniques employed to calibrate the field in the bulk of the magnet. Moreover, results of the tests and issues concerning the mass production of the Resistive Plate Chambers are reported. Final...

  2. A novel spectrometer for studying exotic nuclei with the electron/ion collider ELISe

    International Nuclear Information System (INIS)

    Berg, G.P.A.; Adachi, T.; Harakeh, M.N.; Kalantar-Nayestanaki, N.; Woertche, H.J.; Simon, H.; Koop, I.A.; Couder, M.; Fujiwara, M.

    2011-01-01

    A novel concept of an electron spectrometer developed for the ELISe facility is presented. This spectrometer will be constructed as a part of the international Facility for Antiprotons and Ion Research (FAIR) at GSI Helmholtzzentrum fuer Schwerionenforschung. The spectrometer is designed to analyze electron scattering at the ion-electron interaction region of the NESR and EAR colliding storage rings with a high resolution and a large solid angle. A pre-deflector with a zero-field central channel along the path of the intersecting beam allows the measurement of scattered electrons without interfering with the circulating beams. Ion-optical and magnet design calculations are presented to demonstrate the feasibility and achievement of realistic design specifications.

  3. Associated Particle Tagging (APT) in Magnetic Spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, David V.; Baciak, James E.; Stave, Sean C.; Chichester, David; Dale, Daniel; Kim, Yujong; Harmon, Frank

    2012-10-16

    Summary In Brief The Associated Particle Tagging (APT) project, a collaboration of Pacific Northwest National Laboratory (PNNL), Idaho National Laboratory (INL) and the Idaho State University (ISU)/Idaho Accelerator Center (IAC), has completed an exploratory study to assess the role of magnetic spectrometers as the linchpin technology in next-generation tagged-neutron and tagged-photon active interrogation (AI). The computational study considered two principle concepts: (1) the application of a solenoidal alpha-particle spectrometer to a next-generation, large-emittance neutron generator for use in the associated particle imaging technique, and (2) the application of tagged photon beams to the detection of fissile material via active interrogation. In both cases, a magnetic spectrometer momentum-analyzes charged particles (in the neutron case, alpha particles accompanying neutron generation in the D-T reaction; in the tagged photon case, post-bremsstrahlung electrons) to define kinematic properties of the relevant neutral interrogation probe particle (i.e. neutron or photon). The main conclusions of the study can be briefly summarized as follows: Neutron generator: • For the solenoidal spectrometer concept, magnetic field strengths of order 1 Tesla or greater are required to keep the transverse size of the spectrometer smaller than 1 meter. The notional magnetic spectrometer design evaluated in this feasibility study uses a 5-T magnetic field and a borehole radius of 18 cm. • The design shows a potential for 4.5 Sr tagged neutron solid angle, a factor of 4.5 larger than achievable with current API neutron-generator designs. • The potential angular resolution for such a tagged neutron beam can be less than 0.5o for modest Si-detector position resolution (3 mm). Further improvement in angular resolution can be made by using Si-detectors with better position resolution. • The report documents several features of a notional generator design incorporating the

  4. A personal computer-based nuclear magnetic resonance spectrometer

    Science.gov (United States)

    Job, Constantin; Pearson, Robert M.; Brown, Michael F.

    1994-11-01

    Nuclear magnetic resonance (NMR) spectroscopy using personal computer-based hardware has the potential of enabling the application of NMR methods to fields where conventional state of the art equipment is either impractical or too costly. With such a strategy for data acquisition and processing, disciplines including civil engineering, agriculture, geology, archaeology, and others have the possibility of utilizing magnetic resonance techniques within the laboratory or conducting applications directly in the field. Another aspect is the possibility of utilizing existing NMR magnets which may be in good condition but unused because of outdated or nonrepairable electronics. Moreover, NMR applications based on personal computer technology may open up teaching possibilities at the college or even secondary school level. The goal of developing such a personal computer (PC)-based NMR standard is facilitated by existing technologies including logic cell arrays, direct digital frequency synthesis, use of PC-based electrical engineering software tools to fabricate electronic circuits, and the use of permanent magnets based on neodymium-iron-boron alloy. Utilizing such an approach, we have been able to place essentially an entire NMR spectrometer console on two printed circuit boards, with the exception of the receiver and radio frequency power amplifier. Future upgrades to include the deuterium lock and the decoupler unit are readily envisioned. The continued development of such PC-based NMR spectrometers is expected to benefit from the fast growing, practical, and low cost personal computer market.

  5. Electron spectrometer for gas-phase spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bozek, J.D.; Schlachter, A.S. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    An electron spectrometer for high-resolution spectroscopy of gaseous samples using synchrotron radiation has been designed and constructed. The spectrometer consists of a gas cell, cylindrical electrostatic lens, spherical-sector electron energy analyzer, position-sensitive detector and associated power supplies, electronics and vacuum pumps. Details of the spectrometer design are presented together with some representative spectra.

  6. The SPEDE spectrometer

    Science.gov (United States)

    Papadakis, P.; Cox, D. M.; O'Neill, G. G.; Borge, M. J. G.; Butler, P. A.; Gaffney, L. P.; Greenlees, P. T.; Herzberg, R.-D.; Illana, A.; Joss, D. T.; Konki, J.; Kröll, T.; Ojala, J.; Page, R. D.; Rahkila, P.; Ranttila, K.; Thornhill, J.; Tuunanen, J.; Van Duppen, P.; Warr, N.; Pakarinen, J.

    2018-03-01

    The electron spectrometer, SPEDE, has been developed and will be employed in conjunction with the Miniball spectrometer at the HIE-ISOLDE facility, CERN. SPEDE allows for direct measurement of internal conversion electrons emitted in-flight, without employing magnetic fields to transport or momentum filter the electrons. Together with the Miniball spectrometer, it enables simultaneous observation of γ rays and conversion electrons in Coulomb excitation experiments using radioactive ion beams.

  7. High-effective position time spectrometer in actual measurements of low intensity region of electron spectra

    International Nuclear Information System (INIS)

    Babenkov, M.I.; Zhdanov, V.S.

    2002-01-01

    Magnetic position-time spectrometer was proposed in previous work, where not only electron coordinates in focal plane are measured by position sensitive detector (PSD) but places of their birth in beta source plane of a large area are fixed using another PSD, situated behind it, by quick effects, accompanying radioactive decay. PSD on the basis of macro-channel plates are used. It is succeeded in position-time spectrometer to combine beta sources of a large area with multichannel registration for a wide energy interval, that efficiency of measurements was two orders of magnitude increase d in comparison magnetic apparatus having PSD only in focal plane. Owing to two detectors' switching on coincidence the relation effect/background in increased minimum on two orders of magnitude in comparison with the same apparatus. At some complication of mathematical analysis it was obtained, that high characteristics of position-time spectrometer are kept during the use the magnetic field, providing double focusing. Owning to this focusing the gain the efficiency of measurements will make one more order of magnitude. Presented high-effective position-time spectrometer is supposed to use in the measurements of low-intensity region of electron spectra, which are important for development of fundamental physics. This is the first of all estimation of electron anti-neutrino mass by the form of beta spectrum of tritium in the region of boundary energy. Recently here there was problem of non physical negative values. This problem can be solved by using in measurement of different in principle high-effective spectrometers, which possess improved background properties. A position-time spectrometers belongs to these apparatus, which provides the best background conditions at very large effectiveness of the measurements of tritium beta spectrum in the region of boundary energy with acceptable high resolution. An important advantage of position-time spectrometer is the possibility of

  8. Simulations for a compact electron-positron spectrometer

    International Nuclear Information System (INIS)

    Filep, T.; Krasznahorkay, A.; Csatlos, M.; Gulyas, J.

    2011-01-01

    Complete text of publication follows. In the frame of the ENSAR (FP7) project, we are constructing a Compact Positron- Electron spectrometer (COPE) using toroidal magnetic field. It will be used for studying the internal pair creation process in nuclear transitions. It will look like a miniaturized model of the ATLAS spectrometer at CERN at a scale of 1:100. The mean design parameters are high efficiency, good energy resolution and precise angle reconstruction. By our plans the size of this spectrometer would be limited to a diameter of about 30 cm and length about 20 cm, having 1 % energy- and 2deg angular resolutions. The solid angle of the planned spectrometer will be 2π. It is necessary to develop a geometry in which the inhomogeneity of the field can be easily handled. Prior to the construction it was necessary to perform computer simulations in order to avoid rough construction mistakes. The better approach of the reality with simulations is very important. The problem what we have to solve is very complicated. We need to simulate the magnetic field and trajectory of the particle moving in that field. We started our simulations using the PerMag software package. >From the result we learned the followings: 1) It has no meaning to cover the magnets with iron coat because it complicates the magnetic field. 2) It is not a good idea to form the magnetic one-segment from a big magnet and 12 smaller magnets. The fringing field of the small magnets significantly modifies the magnetic field distribution around the segment. On the other hand the construction of one segment from pieces is very difficult in reality. 3) The best shape for a segment which can easily be constructed is simple box. The PerMag package could simulate the magnetic field only in 2D, but we wanted to do more precise simulation in 3D. The free package developed by the European Synchrotron Radiation Facility (ESRF) was used for the simulation of the magnetic field applying the finite element method

  9. Magnetic field calculation of the Na-4 muon spectrometer

    International Nuclear Information System (INIS)

    Cvach, J.; Il'yushchenko, V.I.; Savin, I.A.; Vorozhtsov, S.B.

    1980-01-01

    A NA-4 muon spectrometer is described. Preliminary results of calculating a magnetic field in a toroidal magnetic detector are given. The spectrometer includes 10 similar supermodules each of which consists of 32 iron discs with 275 cm outer diameter magnetized up to saturation. Each module is an independent detector. The POISSON program is used for calculating magnetic field distribution in a toroidal spectrometer magnet. The results obtained show that a magnetic field of iron is a toroidal one and drops approximately according to the logarithmic law from 21.1 kGs on an inner magnet rig to 17.7 kGs on an outer. Magnet support gives approximately 2 % error

  10. Electron spectroscopy measurements with a shifted analyzing plane setting in the KATRIN main spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Dyba, Stephan [Institut fuer Kernphysik, Uni Muenster (Germany); Collaboration: KATRIN-Collaboration

    2016-07-01

    With the KATRIN (KArlsruhe TRItium Neutrino) experiment the endpoint region of the tritium beta decay will be measured to determine the electron-neutrino mass with a sensitivity of 200 meV/c{sup 2} (90% C.L.). For the high precision which is needed to achieve the sub-eV range a MAC-E filter type spectrometer is used to analyze the electron energy. To understand the various background contributions inside the spectrometer vessel different electric and magnetic field settings were investigated during the last commissioning phase. This talk will focus on the so called shifted analyzing plane measurement in which the field settings were tuned in a way to provide non standard potential barriers within the spectrometer. The different settings allowed to perform a spectroscopic measurement, determining the energy spectrum of background electrons born within the spectrometer.

  11. Electron and Positron Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    Science.gov (United States)

    Aguilar, M.; Aisa, D.; Alvino, A.; Ambrosi, G.; Andeen, K.; Arruda, L.; Attig, N.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Battarbee, M.; Battiston, R.; Bazo, J.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bigongiari, G.; Bindi, V.; Bizzaglia, S.; Bizzarri, M.; Boella, G.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Borsini, S.; Boschini, M. J.; Bourquin, M.; Burger, J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Cascioli, V.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, H.; Cheng, G. M.; Chen, H. S.; Cheng, L.; Chikanian, A.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Coste, B.; Cui, Z.; Dai, M.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Di Masso, L.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Du, W. J.; Duranti, M.; D'Urso, D.; Eline, A.; Eppling, F. J.; Eronen, T.; Fan, Y. Y.; Farnesini, L.; Feng, J.; Fiandrini, E.; Fiasson, A.; Finch, E.; Fisher, P.; Galaktionov, Y.; Gallucci, G.; García, B.; García-López, R.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Gillard, W.; Giovacchini, F.; Goglov, P.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guandalini, C.; Guerri, I.; Guo, K. H.; Habiby, M.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hoffman, J.; Hsieh, T. H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jinchi, H.; Kanishev, K.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Kossakowski, R.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; Kunz, S.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. L.; Li, J. Q.; Li, Q.; Li, Q.; Li, T. X.; Li, W.; Li, Y.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, H.; Lomtadze, T.; Lu, M. J.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lv, S. S.; Majka, R.; Malinin, A.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mo, D. C.; Morescalchi, L.; Mott, P.; Müller, M.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Obermeier, A.; Oliva, A.; Orcinha, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Papi, A.; Pedreschi, E.; Pensotti, S.; Pereira, R.; Pilo, F.; Piluso, A.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Postaci, E.; Putze, A.; Quadrani, L.; Qi, X. M.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rodríguez, I.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Sandweiss, J.; Saouter, P.; Sbarra, C.; Schael, S.; Schmidt, S. M.; Schuckardt, D.; von Dratzig, A. Schulz; Schwering, G.; Scolieri, G.; Seo, E. S.; Shan, B. S.; Shan, Y. H.; Shi, J. Y.; Shi, X. Y.; Shi, Y. M.; Siedenburg, T.; Son, D.; Spada, F.; Spinella, F.; Sun, W.; Sun, W. H.; Tacconi, M.; Tang, C. P.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türkoǧlu, C.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vaurynovich, S.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Wang, L. Q.; Wang, Q. L.; Wang, R. S.; Wang, X.; Wang, Z. X.; Weng, Z. L.; Whitman, K.; Wienkenhöver, J.; Wu, H.; Xia, X.; Xie, M.; Xie, S.; Xiong, R. Q.; Xin, G. M.; Xu, N. S.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Ye, Q. H.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, J. H.; Zhang, M. T.; Zhang, X. B.; Zhang, Z.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; Zurbach, C.; AMS Collaboration

    2014-09-01

    Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ˜30 GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

  12. Multiparticle magnetic spectrometer with dE/dx and TRD particle identification

    International Nuclear Information System (INIS)

    Lindenbaum, S.J.; Longacre, R.S.

    1981-01-01

    Recent advances in detector development by BNL, CCNY and other groups have made possible new designs of fast high resolution large effective solid angle magnetic multiparticle spectrometers with excellent particle tracking, momentum measurement, and identification capability. These new spectrometers are relatively compact and relatively low cost electronics have been developed for them. Thus the cost is relatively low. These techniques are applied here primarily for design of spectrometers for low p/sub t/ and other physics (at moderate and even high p/sub t/) in the ISABELLE small angle hall. However, one should keep in mind that these techniques can be utilized in many other applications

  13. Design of magnetic analysis system for magnetic proton recoil spectrometer

    International Nuclear Information System (INIS)

    Qi Jianmin; Jiang Shilun; Zhou Lin; Peng Taiping

    2010-01-01

    Magnetic proton recoil (MPR) spectrometer is a novel diagnostic instrument with high performance for measurements of the neutron spectra from inertial confinement fusion (ICF) experiments and high power fusion devices. The design of the magnetic analysis system, which is a key part of the compact MPR-type spectrometer, has been completed through two-dimensional beam transport simulations and three-dimensional particle transport simulation. The analysis of the system's parameters and performances was performed, as well as system designs based on preferential principles of energy resolution, detection efficiency, and count rate, respectively. The results indicate that the magnetic analysis system can achieve a detection efficiency of 10 -5 ∼ 10 -4 level at the resolution range of 1.5% to 3.0% and fulfill the design goals of the compact MPR spectrometer. (authors)

  14. Electron and Positron Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    CERN Document Server

    Aguilar, M; Alvino, A; Ambrosi, G; Andeen, K; Arruda, L; Attig, N; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bigongiari, G; Bindi, V; Bizzaglia, S; Bizzarri, M; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Borsini, S; Boschini, M J; Bourquin, M; Burger, J; Cadoux, F; Cai, X D; Capell, M; Caroff, S; Casaus, J; Cascioli, V; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, H; Cheng, G M; Chen, H S; Cheng, L; Chikanian, A; Chou, H Y; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Cui, Z; Dai, M; Delgado, C; Della Torre, S; Demirköz, M B; Derome, L; Di Falco, S; Di Masso, L; Dimiccoli, F; Díaz, C; von Doetinchem, P; Du, W J; Duranti, M; D’Urso, D; Eline, A; Eppling, F J; Eronen, T; Fan, Y Y; Farnesini, L; Feng, J; Fiandrini, E; Fiasson, A; Finch, E; Fisher, P; Galaktionov, Y; Gallucci, G; García, B; García-López, R; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Gillard, W; Giovacchini, F; Goglov, P; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guandalini, C; Guerri, I; Guo, K H; Habiby, M; Haino, S; Han, K C; He, Z H; Heil, M; Hoffman, J; Hsieh, T H; Huang, Z C; Huh, C; Incagli, M; Ionica, M; Jang, W Y; Jinchi, H; Kanishev, K; Kim, G N; Kim, K S; Kirn, Th; Kossakowski, R; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; Kunz, S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H T; Lee, S C; Leluc, C; Li, H L; Li, J Q; Li, Q; Li, Q; Li, T X; Li, W; Li, Y; Li, Z H; Li, Z Y; Lim, S; Lin, C H; Lipari, P; Lippert, T; Liu, D; Liu, H; Lomtadze, T; Lu, M J; Lu, Y S; Luebelsmeyer, K; Luo, F; Luo, J Z; Lv, S S; Majka, R; Malinin, A; Mañá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D C; Morescalchi, L; Mott, P; Müller, M; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Obermeier, A; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Papi, A; Pedreschi, E; Pensotti, S; Pereira, R; Pilo, F; Piluso, A; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Postaci, E; Putze, A; Quadrani, L; Qi, X M; Rancoita, P G; Rapin, D; Ricol, J S; Rodríguez, I; Rosier-Lees, S; Rozhkov, A; Rozza, D; Sagdeev, R; Sandweiss, J; Saouter, P; Sbarra, C; Schael, S; Schmidt, S M; Schuckardt, D; Schulz von Dratzig, A; Schwering, G; Scolieri, G; Seo, E S; Shan, B S; Shan, Y H; Shi, J Y; Shi, X Y; Shi, Y M; Siedenburg, T; Son, D; Spada, F; Spinella, F; Sun, W; Sun, W H; Tacconi, M; Tang, C P; Tang, X W; Tang, Z C; Tao, L; Tescaro, D; Ting, Samuel C C; Ting, S M; Tomassetti, N; Torsti, J; Türkoğlu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vaurynovich, S; Vecchi, M; Velasco, M; Vialle, J P; Wang, L Q; Wang, Q L; Wang, R S; Wang, X; Wang, Z X; Weng, Z L; Whitman, K; Wienkenhöver, J; Wu, H; Xia, X; Xie, M; Xie, S; Xiong, R Q; Xin, G M; Xu, N S; Xu, W; Yan, Q; Yang, J; Yang, M; Ye, Q H; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, J H; Zhang, M T; Zhang, X B; Zhang, Z; Zheng, Z M; Zhuang, H L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P; Zurbach, C

    2014-01-01

    Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30  GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

  15. Magnetic spectrometer of the DEUTERON-2 set-up

    International Nuclear Information System (INIS)

    Ajvazyan, R.V.; Alanakyan, K.V.; Amaryan, M.J.

    1989-01-01

    A magnetic spectrometer of the two-arm DEUTERON-2 set-up of the Erevan Physical Institute is described. It is shown that the rejection factor for electrons and pions is 10 -2 - 10 -3 . The positively charged particles in the momentum range up to 1.5 GeV/c are identified by momentum and time-of-flight measurements. The main characteristics of the spectrometer are: momentum and angular acceptance δp/p = 46%, Δθ = 4 deg, solid angle ΔΩ = 2.75 msr, momentum resolution δp/p = 1.5%, angular resolutions δθ = 0.6 deg, δφ = 2 deg. The intervals of measured momentum and the polar scattering anlge are 0.5-3 GeV/c and 10-30 deg, 68-90 deg respectively. 7 refs.; 11 figs

  16. The magnetic shield design and simulation of an X-ray spectrometer for Chang'E mission

    International Nuclear Information System (INIS)

    Zhang Jiayu; Wang Huanyu; Zhang Chengmo; Yang Jiawei; Liang Xiaohua; Wang Jinzhou; Cao Xuelei; Gao Min; Cui Xingzhu; Peng Wenxi

    2008-01-01

    Basic design methods about the magnetic shield of an X-ray spectrometer for Chang'E Mission were introduced in this paper. The real magnetic field distribution was obtained through the measure experiment, and according to the measure results, the simulation to evaluate the magnetic shield effect was carded on. The results showed that the collimator can play a good role in magnetic shield to the electron. (authors)

  17. Magnetic and electric deflector spectrometers for ion emission analysis from laser generated plasma

    Directory of Open Access Journals (Sweden)

    Torrisi Lorenzo

    2018-01-01

    Full Text Available The pulsed laser-generated plasma in vacuum and at low and high intensities can be characterized using different physical diagnostics. The charge particles emission can be characterized using magnetic, electric and magnet-electrical spectrometers. Such on-line techniques are often based on time-of-flight (TOF measurements. A 90° electric deflection system is employed as ion energy analyzer (IEA acting as a filter of the mass-to-charge ratio of emitted ions towards a secondary electron multiplier. It determines the ion energy and charge state distributions. The measure of the ion and electron currents as a function of the mass-to-charge ratio can be also determined by a magnetic deflector spectrometer, using a magnetic field of the order of 0.35 T, orthogonal to the ion incident direction, and an array of little ion collectors (IC at different angles. A Thomson parabola spectrometer, employing gaf-chromix as detector, permits to be employed for ion mass, energy and charge state recognition. Mass quadrupole spectrometry, based on radiofrequency electric field oscillations, can be employed to characterize the plasma ion emission. Measurements performed on plasma produced by different lasers, irradiation conditions and targets are presented and discussed. Complementary measurements, based on mass and optical spectroscopy, semiconductor detectors, fast CCD camera and Langmuir probes are also employed for the full plasma characterization. Simulation programs, such as SRIM, SREM, and COMSOL are employed for the charge particle recognition.

  18. Magnetic and electric deflector spectrometers for ion emission analysis from laser generated plasma

    Science.gov (United States)

    Torrisi, Lorenzo; Costa, Giuseppe; Ceccio, Giovanni; Cannavò, Antonino; Restuccia, Nancy; Cutroneo, Mariapompea

    2018-01-01

    The pulsed laser-generated plasma in vacuum and at low and high intensities can be characterized using different physical diagnostics. The charge particles emission can be characterized using magnetic, electric and magnet-electrical spectrometers. Such on-line techniques are often based on time-of-flight (TOF) measurements. A 90° electric deflection system is employed as ion energy analyzer (IEA) acting as a filter of the mass-to-charge ratio of emitted ions towards a secondary electron multiplier. It determines the ion energy and charge state distributions. The measure of the ion and electron currents as a function of the mass-to-charge ratio can be also determined by a magnetic deflector spectrometer, using a magnetic field of the order of 0.35 T, orthogonal to the ion incident direction, and an array of little ion collectors (IC) at different angles. A Thomson parabola spectrometer, employing gaf-chromix as detector, permits to be employed for ion mass, energy and charge state recognition. Mass quadrupole spectrometry, based on radiofrequency electric field oscillations, can be employed to characterize the plasma ion emission. Measurements performed on plasma produced by different lasers, irradiation conditions and targets are presented and discussed. Complementary measurements, based on mass and optical spectroscopy, semiconductor detectors, fast CCD camera and Langmuir probes are also employed for the full plasma characterization. Simulation programs, such as SRIM, SREM, and COMSOL are employed for the charge particle recognition.

  19. Magnetic energy analyser for slow electrons

    International Nuclear Information System (INIS)

    Limberg, W.

    1974-08-01

    A differential spectrometer with high time and energy resolution has been developed using the principle of energy analysis with a longitudinal homogeneous magnetic field. This way it is possible to measure the energy distribution of low energy electrons (eV-range) in the presence of high energy electrons without distortions by secondary electrons. The functioning and application of the analyzer is demonstrated by measuring the energy distributions of slow electrons emitted by a filament. (orig.) [de

  20. QQDDQ magnet spectrometer 'BIG KARL'

    Energy Technology Data Exchange (ETDEWEB)

    Martin, S A; Hardt, A; Meissburger, J; Berg, G P.A.; Hacker, U; Huerlimann, W; Roemer, J G.M.; Sagefka, T; Retz, A; Schult, O W.B.

    1983-09-01

    A magnet spectrometer consisting of two quadrupoles, two dipole magnets and another larger quadrupole in front of the detector was designed and installed at the nuclear research institute of the KFA Juelich. It has been used for charged-particle spectroscopy at the isochronous cyclotron since early 1979. Special features of the spectrometer are variable and high dispersion, coils for higher order field corrections in the dipole magnets and a focal plane perpendicular to the optical axis. A large mass-energy product of mE/q/sup 2/ < 540 u x MeV, an angular acceptance of d..cap omega..<12.5 msr, a high resolving power of p/..delta..p up to 3 x 10/sup 4/ and the possibility of kinematical corrections up to K=0.8 make the instrument a very versatile tool for many experiments in the fields of nuclear and atomic physics. 51 references.

  1. A 5 tesla superconducting magnet and cryostats for an EPR/FMR spectrometer

    NARCIS (Netherlands)

    Reuvekamp, E.M.C.M.; Gerritsma, G.J.; ten Kate, Herman H.J.; van de Klundert, L.J.M.

    1988-01-01

    A description is given of the cryogenic part of an electron paramagnetic resonance (EPR)/ferromagnetic resonance (FMR) spectrometer using Ka-band (26.5-40 GHz) and U-band (40-60 GHz) frequencies for resonance measurements on large magnetic thin-films. The unit has two cryostats; the first has a

  2. What Happened with Spectrometer Magnet 2B

    International Nuclear Information System (INIS)

    Green, Michael A.

    2010-01-01

    The spectrometer solenoid is supposed to be the first magnets installed in MICE (1)-(4). This report described what happened during the test of the MICE spectrometer solenoid 2B. First, the report describes the temperatures in the magnet, the cooler top plate and the shield during the run where the magnet quenched at 258 A. During this quench, a lead between the bottom of the HTS leads and the diode bank burned out causing the magnet to quench. Second, three methods for measuring the net heat flow into the cold mass are described. Third, there is a discussion of possible resistive heating in the HTS leads between liquid helium temperature and the copper plate, which is at about 50 K. Fourth, there is a discussion of the measured first stage heat loads in the magnet, when there is no current in the magnet. The first stage heat load calculations are based on knowing the first stage temperatures of the three two-stage pulse tube coolers and the single stage GM cooler. Fifth, the estimated heat load to the first stage when the magnet has current in it is discussed. Sixth, there is a comparison of the stage 1 heat loads in magnet 1A (5), magnet 2A (6), and magnet 2B (7). Finally there is a discussion of recommended changes for improving the spectrometer solenoids so that the coolers can keep them cold.

  3. Electron volt neutron spectrometers

    International Nuclear Information System (INIS)

    Pietropaolo, A.; Senesi, R.

    2011-01-01

    The advent of pulsed neutron sources has made available intense fluxes of epithermal neutrons (500 meV ≤E≤100 eV ). The possibility to open new investigations on condensed matter with eV neutron scattering techniques, is related to the development of methods, concepts and devices that drive, or are inspired by, emerging studies at this energy scale. Electron volt spectrometers have undergone continuous improvements since the construction of the first prototype instruments, but in the last decade major breakthroughs have been accomplished in terms of resolution and counting statistics, leading, for example, to the direct measurement of the proton 3-D Born–Oppenheimer potential in any material, or to quantitatively probe nuclear quantum effects in hydrogen bonded systems. This paper reports on the most effective methods and concepts for energy analysis and detection, as well as devices for the optimization of electron volt spectrometers for different applications. This is set in the context of the progress made up to date in instrument development. Starting from early stages of development of the technique, particular emphasis will be given to the Vesuvio eV spectrometer at the ISIS neutron source, the first spectrometer where extensive scientific, as well as research and development programmes have been carried out. The potential offered by this type of instrumentation, from single particle excitations to momentum distribution studies, is then put in perspective into the emerging fields of eV spectroscopy applied to cultural heritages and neutron irradiation effects in electronics. - Highlights: ► Neutron spectrometers at eV energies. ► Methods and techniques for eV neutrons counting at spallation sources. ► Scattering, imaging and radiation hardness tests with multi-eV neutrons.

  4. Electron-ion-x-ray spectrometer system

    International Nuclear Information System (INIS)

    Southworth, S.H.; Deslattes, R.D.; MacDonald, M.A.

    1993-01-01

    The authors describe a spectrometer system developed for electron, ion, and x-ray spectroscopy of gas-phase atoms and molecules following inner-shell excitation by tunable synchrotron radiation. The spectrometer has been used on beamline X-24A at the National Synchrotron Light Source for excitation-dependent studies of Ar L-shell and K-shell photoexcitation and vacancy decay processes. The instrumentation and experimental methods are discussed, and examples are given of electron spectra and coincidence spectra between electrons and fluorescent x-rays

  5. Implement of a magnetic spectrometer at the CERN intersecting stockage rings (900 spectrometer in the R608 experiment)

    International Nuclear Information System (INIS)

    Reyrolle, M.

    1985-01-01

    By adding a new spectrometer at 90 0 in the R608 experiment at CERN (ISR) we can search correlations between some systems of particles fully measured in the forward and transverse directions. The corresponding new electronic trigger, which selects events with momentum above a chosen threshold, is mixed or not to the forward trigger, in order to record correlated or inclusive data from the collisions p-p, p-anti-p, α-α. In the 90 0 spectrometer, we build drift chambers, set before the dipolar magnet. We studied the spatial resolution and the methods to associate tracks before and after this magnet. We developed the method to determine the momenta, by taking account of the variations of the deflecting power: the accuracy of this method is better than O.3%, and the global resolution is about 0.01 P 2 . We proposed also how to identify the particles from time of flight measurements and aerogel cerenkov counters [fr

  6. ESR spectrometer with a loop-gap resonator for cw and time resolved studies in a superconducting magnet.

    Science.gov (United States)

    Simon, Ferenc; Murányi, Ferenc

    2005-04-01

    The design and performance of an electron spin resonance spectrometer operating at 3 and 9 GHz microwave frequencies combined with a 9-T superconducting magnet are described. The probehead contains a compact two-loop, one gap resonator, and is inside the variable temperature insert of the magnet enabling measurements in the 0-9T magnetic field and 1.5-400 K temperature range. The spectrometer allows studies on systems where resonance occurs at fields far above the g approximately 2 paramagnetic condition such as in antiferromagnets. The low quality factor of the resonator allows time resolved experiments such as, e.g., longitudinally detected ESR. We demonstrate the performance of the spectrometer on the NaNiO2 antiferromagnet, the MgB2 superconductor, and the RbC60 conducting alkaline fulleride polymer.

  7. Highly effective portable beta spectrometer for precise depth selective electron Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Aldiyarov, N.U.; Kadyrzhanov, K.K.; Seytimbetov, A.M.; Zhdanov, V.S.

    2007-01-01

    Full text: More broad application of the nuclear-physical method of precise Depth Selective Electron Moessbauer Spectroscopy (DS EMS) is limited by insufficient accessibility of highly-effective beta spectrometers with acceptable resolution. It should be mentioned that the method DS EMS is realized at a combined installation that consists of a highly-effective beta spectrometer and a conventional portable nuclear gamma-resonance spectrometer. Yet few available beta spectrometers have sophisticated design and controlling; in most cases they are cumbersome. All the attempts to simplify beta spectrometers resulted in noticeable worsening of depth resolution for the DS EMS method making the measurements non precise. There is currently an obvious need in a highly-effective portable easily controlled beta spectrometer. While developing such portable beta spectrometer, it is more promising to use as basis a simpler spectrometer, which has ratio of sample size to spectrometer size of about five times. The paper presents an equal-arm version of a highly-effective portable beta spectrometer with transverse heterogeneous sector magnetic field that assures double focusing. The spectrometer is equipped with a large-area non-equipotential source (a sample under investigation) and a position-sensitive detector. This portable spectrometer meets all requirements for achievement of the DS EMS depth resolution close to the physical limit and demonstrates the following main characteristics: equilibrium orbit radius ρ 0 = 80 mm, instrumental energy resolution 0.6 % at solid angle 1 % of 4π steradian, area of non-equipotential source ∼ 80 mm 2 , registration by position-sensitive detector of ∼ 10 % of the energy interval. Highly-effective portable beta spectrometer assures obtaining Moessbauer data with depth resolution close to physical limit of the DS EMS method. So in measurements at conversion and Auger electrons with energies of about units of keV and above, the achieved

  8. Gamma-to-electron magnetic spectrometer (GEMS): An energy-resolved {gamma}-ray diagnostic for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.; Herrmann, H. W.; Mack, J. M.; Young, C. S.; Barlow, D. B.; Schillig, J. B.; Sims, J. R. Jr.; Lopez, F. E.; Mares, D.; Oertel, J. A.; Hayes-Sterbenz, A. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hilsabeck, T. J.; Wu, W. [General Atomics, PO Box 85608, San Diego, California 92186 (United States); Moy, K. [National Security Technologies, Special Technologies Laboratory, Santa Barbara, California 93111 (United States); Stoeffl, W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2012-10-15

    The gamma-to-electron magnetic spectrometer, having better than 5% energy resolution, is proposed to resolve {gamma}-rays in the range of E{sub o}{+-} 20% in single shot, where E{sub o} is the central energy and is tunable from 2 to 25 MeV. Gamma-rays from inertial confinement fusion implosions interact with a thin Compton converter (e.g., beryllium) located at approximately 300 cm from the target chamber center (TCC). Scattered electrons out of the Compton converter enter an electromagnet placed outside the NIF chamber (approximately 600 cm from TCC) where energy selection takes place. The electromagnet provides tunable E{sub o} over a broad range in a compact manner. Energy resolved electrons are measured by an array of quartz Cherenkov converters coupled to photomultipliers. Given 100 detectable electrons in the energy bins of interest, 3 Multiplication-Sign 10{sup 14} minimum deuterium/tritium (DT) neutrons will be required to measure the 4.44 MeV {sup 12}C {gamma}-rays assuming 200 mg/cm{sup 2} plastic ablator areal density and 3 Multiplication-Sign 10{sup 15} minimum DT neutrons to measure the 16.75 MeV DT {gamma}-ray line.

  9. The SPEDE electron spectrometer

    CERN Document Server

    O'Neill, George

    This thesis presents SPEDE (SPectrometer for Electron DEtection) and documents its construction, testing and performance during commissioning at Jyvaskyla, Finland, before deployment at the HIE-ISOLDE facility at CERN coupled with the MINIBALL array to perform in-beam electron-gamma spectroscopy using post-accelerated radioactive ion beams. Commissioning experiments took place in two two-day stints during spring 2015, coupled with several JUROGAMII gamma-detectors. This spectrometer will help aid in fully understanding exotic regions of the nuclear chart such as regions with a high degree of octupole deformation, and in those nuclei exhibiting shape coexistence. For the rst time, electron spectroscopy has been performed at the target position from states populated in accelerated nuclei via Coulomb excitation. The FWHM of SPEDE is approximately 7 keV at 320 keV, and Doppler correction was possible to improve Doppler broadened peaks. The results are intended to give the reader a full understanding of the dete...

  10. A silicon microstrip detector in a magnetic spectrometer for high-resolution electron scattering experiments at the S-DALINAC

    International Nuclear Information System (INIS)

    Lenhardt, A.W.; Bonnes, U.; Burda, O.; Neumann-Cosel, P. von; Platz, M.; Richter, A.; Watzlawik, S.

    2006-01-01

    A silicon microstrip detector was developed as focal plane detector of the 169.7 deg. magic angle double-focussing spectrometer at the superconducting Darmstadt electron linear accelerator (S-DALINAC). It allows experiments with minimum ionizing electrons at data rates up to 100 kHz, utilizing the maximum resolution of the spectrometer achievable in dispersion-matching mode

  11. A superconducting electron spectrometer

    International Nuclear Information System (INIS)

    Guttormsen, M.; Huebel, H.; Grumbkow, A. von

    1983-03-01

    The set-up and tests of an electron spectrometer for in-beam conversion electron measurements are described. A superconducting solenoid is used to transport the electrons from the target to cooled Si(Li) detectors. The solenoid is designed to produce either a homogeneous axially symmetric field of up to 2 Tesla or a variety of field profiles by powering the inner and outer set of coils of the solenoid separately. The electron trajectories resulting for various field profiles are discussed. In-beam electron spectra taken in coincidence with electrons, gammas and alpha-particles are shown. (Auth.)

  12. Alpha Magnetic Spectrometer (AMS) for Extraterrestrial Study of Antimatter, Matter and Missing Matter on the International Space Station

    CERN Multimedia

    Lee, M W; Lipari, P; Berdugo perez, J F; Borgia, B; Lazzizzera, I; Battarbee, M C; Valente, V; Bartoloni, A

    2002-01-01

    % RE1\\\\ \\\\ AMS is the first magnetic particle physics spectrometer to be installed on the International Space Station. With a superconducting magnetic spectrometer, AMS will provide accurate measurements of electrons, positrons, protons, antiprotons and various nuclei up to TeV region. NASA has scheduled to install this detector on the International Space Station in May 2003. The first flight of AMS was done with a permanent magnet and this prototype detector has provided accurate information on the limit of the existence of antihelium. It also showed that proton and electron -positron spectra exhibited a complicated behavior in the near earth orbit. The construction of AMS is being carried out in Switzerland, Germany, Italy, France, Finland, Spain, Portugal, Romania, Russia, Taiwan, China and the United States. NASA provides the use of the space shuttle and the space station, as well as mission management.

  13. Inside the ETH spectrometer magnet

    CERN Multimedia

    1974-01-01

    The ETH spectrometer magnet being prepared for experiment S134, which uses a frozen spin polarized target to study the associated production of a kaon and a lambda by negative pions interacting with protons (CERN-ETH, Zurich-Helsinki-Imperial College, London-Southampton Collaboration). (See Photo Archive 7406316)

  14. Magnetic spectrometer control system

    International Nuclear Information System (INIS)

    Lecca, L.A.; Di Paolo, Hugo; Fernandez Niello, Jorge O.; Marti, Guillermo V; Pacheco, Alberto J.; Ramirez, Marcelo

    2003-01-01

    The design and implementation of a new computerized control system for the several devices of the magnetic spectrometer at TANDAR Laboratory is described. This system, as a main difference from the preexisting one, is compatible with almost any operating systems of wide spread use available in PC. This allows on-line measurement and control of all signals from any terminal of a computer network. (author)

  15. Monte-Carlo study of the influence of backscattered electrons on the transmission of a mini-orange β spectrometer

    Science.gov (United States)

    Detistov, Pavel; Balabanski, Dimiter L.

    2015-04-01

    This work work is a part of the performance investigation of the recently constructed Mini-Orange beta spectrometer. The spectrometer has eight different configurations using three different magnet shapes and combination of three, four, and six magnet pieces allowing detection of electrons in wide kinetic energy range. The performance of the device is studied using the GEANT4 simulation tool. Evaluation of the device's basic parameters has been made, paying special attention to the backscattering, for which a study of the dependence of this process on the energy and the angle is made.

  16. A novel electrostatic ion-energy spectrometer by the use of a proposed ``self-collection'' method for secondary-electron emission from a metal collector

    Science.gov (United States)

    Hirata, M.; Nagashima, S.; Cho, T.; Kohagura, J.; Yoshida, M.; Ito, H.; Numakura, T.; Minami, R.; Kondoh, T.; Nakashima, Y.; Yatsu, K.; Miyoshi, S.

    2003-03-01

    For the purpose of end-loss-ion energy analyses in open-field plasmas, a newly developed electrostatic ion-energy spectrometer is proposed on the basis of a "self-collection" principle for secondary-electron emission from a metal collector. The ion-energy spectrometer is designed with multiple grids for analyzing incident ion energies, and a set of parallelly placed metal plates with respect to lines of ambient magnetic forces in an open-ended device. One of the most important characteristic properties of this spectrometer is the use of our proposed principle of a "self-collection" mechanism due to E×B drifts for secondary electrons emitted from the grounded metal-plate collector by the use of no further additional magnetic systems except the ambient open-ended fields B. The proof-of-principle and characterization experiments are carried out by the use of a test-ion-beam line along with an additional use of a Helmholtz coil system for the formation of open magnetic fields similar to those in the GAMMA 10 end region. The applications of the developed ion-energy spectrometer for end-loss-ion diagnostics in the GAMMA 10 plasma experiments are demonstrated under the conditions with simultaneous incidence of energetic electrons produced by electron-cyclotron heatings for end-loss-plugging potential formation, since these electrons have contributed to disturb these ion signals from conventional end-loss-ion detectors.

  17. The Livermore Free-Electron Laser Program Magnet Test Laboratory

    International Nuclear Information System (INIS)

    Burns, M.J.; Kulke, B.; Deis, G.A.; Frye, R.W.; Kallman, J.S.; Ollis, C.W.; Tyler, G.C.; Van Maren, R.D.; Weiss, W.C.

    1987-01-01

    The Lawrence Livermore National Laboratory (LLNL) Free-Electron Laser Program Magnet Test Laboratory supports the ongoing development of the Induction Linac Free Electron Laser (IFEL) and uses magnetic field measurement systems that are useful in the testing of long periodic magnetic structures, electron-beam transport magnets, and spectrometer magnets. The major systems described include two computer-controlled, three-axis Hall probe-and-search coil transports with computer-controlled data acquisition; a unique, automated-search coil system used to detect very small inaccuracies in wiggler fields; a nuclear magnetic resonance (NMR)-based Hall probe-calibration facility; and a high-current DC ion source using heavy ions of variable momentum to model the transport of high-energy electrons. Additionally, a high-precision electron-beam-position monitor for use within long wigglers that has a positional resolution of less than 100 μm is under development in the laboratory and will be discussed briefly. Data transfer to LLNL's central computing facility and on-line graphics enable us to analyze large data sets quickly. 3 refs

  18. The calibration of spectrometers for Auger electron and X-ray photoelectron spectrometers part I - an absolute traceable energy calibration for electron spectrometers

    International Nuclear Information System (INIS)

    Smith, G.C.; Seah, M.P.; Anthony, M.T.

    1991-01-01

    Experiments have been made to provide calibrated kinetic energy values for AES peaks in order to calibrate Auger electron spectrometers of various resolving powers. The kinetic energies are measured using a VG Scientific ESCALAB 2 which has power supplies appropriate for AES measurements in both the constant ΔE and constant ΔE/E modes. The absolute calibration of the energy scale is obtained by the development of a new measurement chain which, in turn, is calibrated in terms of the post-1990 representation of electron volts using XPS peaks with a traceable kinetic energy accuracy of 0.02 eV. The effects of instrumental and operating parameters, including the spectrometer dispersion and stray magnetic fields, are all assessed and contribute errors for three peaks not exceeding 0.06 eV and for two peaks not exceeding 0.03 eV. Calibrated positions in the direct spectrum are given for the Cu M 2,3 VV, Au N 6,7 VV, Ag M 4 NN, Cu L 3 VV and Au M 5 N 6,7 N 6,7 transitions at 0.2 eV resolution, referred to both the Standard Vacuum Level and the Fermi level. For the derivative spectrum the positions of the negative excursions are derived numerically by computer from this data and are established with the same accuracy. Data are tabulated for the above peaks in both the direct and differentiated modes for the popular resolutions of 0.15%, 0.3% and 0.6% produced by Gaussian broadening of the high resolution spectra. Differentiations are effected by both sinusoidal modulation and Savitzky-Golay functions of 2 eV and 5 eV peak-to-peak

  19. Dual Electron Spectrometer for Magnetospheric Multiscale Mission: Results of the Comprehensive Tests of the Engineering Test Unit

    Science.gov (United States)

    Avanov, Levon A.; Gliese, Ulrik; Mariano, Albert; Tucker, Corey; Barrie, Alexander; Chornay, Dennis J.; Pollock, Craig James; Kujawski, Joseph T.; Collinson, Glyn A.; Nguyen, Quang T.; hide

    2011-01-01

    The Magnetospheric Multiscale mission (MMS) is designed to study fundamental phenomena in space plasma physics such as a magnetic reconnection. The mission consists of four spacecraft, equipped with identical scientific payloads, allowing for the first measurements of fast dynamics in the critical electron diffusion region where magnetic reconnection occurs and charged particles are demagnetized. The MMS orbit is optimized to ensure the spacecraft spend extended periods of time in locations where reconnection is known to occur: at the dayside magnetopause and in the magnetotail. In order to resolve fine structures of the three dimensional electron distributions in the diffusion region (reconnection site), the Fast Plasma Investigation's (FPI) Dual Electron Spectrometer (DES) is designed to measure three dimensional electron velocity distributions with an extremely high time resolution of 30 ms. In order to achieve this unprecedented sampling rate, four dual spectrometers, each sampling 180 x 45 degree sections of the sky, are installed on each spacecraft. We present results of the comprehensive tests performed on the DES Engineering & Test Unit (ETU). This includes main parameters of the spectrometer such as energy resolution, angular acceptance, and geometric factor along with their variations over the 16 pixels spanning the 180-degree tophat Electro Static Analyzer (ESA) field of view and over the energy of the test beam. A newly developed method for precisely defining the operational space of the instrument is presented as well. This allows optimization of the trade-off between pixel to pixel crosstalk and uniformity of the main spectrometer parameters.

  20. Improvement of the intrinsic time resolving power of the Cologne iron-free orange type electron spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Regis, J.-M.; Materna, Th.; Pascovici, G.; Christen, S.; Dewald, A.; Fransen, C.; Jolie, J.; Petkov, P.; Zell, K. O. [Institut fuer Kernphysik (IKP), Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2010-11-15

    Conversion electron spectroscopy represents an important tool for nuclear structure analysis of medium and heavy nuclei. Two iron-free magnetic electron spectrometers of the orange type have been installed at the Institute for Nuclear Physics of the University of Cologne. The very large transmission of 15% and the very good energy resolution of 1% makes the iron-free orange spectrometer a powerful instrument. By means of fast timing techniques, lifetimes of nuclear excited states can be measured with an accuracy better than 20 ps. For the first time, the energy dependent centroid position of prompt events yielding the time-walk characteristics (the prompt curve) of the orange spectrometer fast timing setup has been measured using prompt secondary {delta}-electrons generated in a pulsed beam experiment. The prompt curve calibrated as a function of energy allows precise lifetime determination down to a few tens of picoseconds by the use of the centroid shift method.

  1. The electronic system of Beijing spectrometer

    International Nuclear Information System (INIS)

    Xi Deming

    1990-01-01

    Beijing Spectrometer (BES) in an experimental facility of high energy physics on Beijing Electron Positron Collider (BEPC). A brief description including the global design, the read out circuits, the performances and the recent status of its electronic system is presented

  2. Electron spectrometers with internal conversion

    International Nuclear Information System (INIS)

    Suita, J.C.; Lemos Junior, O.F.; Auler, L.T.; Silva, A.G. da

    1981-01-01

    The efforts that the Department of Physics (DEFI) of Institute of Nuclear Engineering (IEN) are being made aiming at adjusting the electron spectrometers with internal conversion to its necessity, are shown. (E.G.) [pt

  3. Monte-Carlo study of the influence of backscattered electrons on the transmission of a mini-orange β spectrometer

    International Nuclear Information System (INIS)

    Detistov, Pavel; Balabanski, Dimiter L

    2015-01-01

    This work work is a part of the performance investigation of the recently constructed Mini-Orange beta spectrometer. The spectrometer has eight different configurations using three different magnet shapes and combination of three, four, and six magnet pieces allowing detection of electrons in wide kinetic energy range. The performance of the device is studied using the GEANT4 simulation tool. Evaluation of the device's basic parameters has been made, paying special attention to the backscattering, for which a study of the dependence of this process on the energy and the angle is made. (paper)

  4. Electronic THz-spectrometer for plasmonic enhanced deep subwavelength layer detection

    NARCIS (Netherlands)

    Berrier, A.; Schaafsma, M.C.; Gómez Rivas, J.; Schäfer-Eberwein, H.; Haring Bolivar, P.; Tripodi, L.; Matters-Kammerer, M.K.

    2015-01-01

    We demonstrate the operation of a miniaturized all-electronic CMOS based THz spectrometer with performances comparable to that of a THz-TDS spectrometer in the frequency range 20 to 220 GHz. The use of this all-electronic THz spectrometer for detection of a thin TiO2 layer and a B. subtilis bacteria

  5. Conceptual design of the gamma-to-electron magnetic spectrometer for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y., E-mail: yhkim@lanl.gov; Herrmann, H. W.; Jorgenson, H. J.; Barlow, D. B.; Young, C. S.; Lopez, F. E.; Oertel, J. A.; Batha, S. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Stoeffl, W.; Casey, D.; Clancy, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hilsabeck, T. [General Atomics, San Diego, California 92186 (United States); Moy, K. [National Security Technologies, Special Technologies Laboratory, Santa Barbara, California 93111 (United States)

    2014-11-15

    The Gamma-to-Electron Magnetic Spectrometer (GEMS) diagnostic is designed to measure the prompt γ-ray energy spectrum during high yield deuterium-tritium (DT) implosions at the National Ignition Facility (NIF). The prompt γ-ray spectrum will provide “burn-averaged” observables, including total DT fusion yield, total areal density (ρR), ablator ρR, and fuel ρR. These burn-averaged observables are unique because they are essentially averaged over 4π, providing a global reference for the line-of-sight-specific measurements typical of x-ray and neutron diagnostics. The GEMS conceptual design meets the physics-based requirements: ΔE/E = 3%–5% can be achieved in the range of 2–25 MeV γ-ray energy. Minimum DT neutron yields required for 15% measurement uncertainty at low-resolution mode are: 5 × 10{sup 14} DT-n for ablator ρR (at 0.2 g/cm{sup 2}); 2 × 10{sup 15} DT-n for total DT yield (at 4.2 × 10{sup −5} γ/n); and 1 × 10{sup 16} DT-n for fuel ρR (at 1 g/cm{sup 2})

  6. A highly polarized hydrogen/deuterium internal gas target embedded in a toroidal magnetic spectrometer

    International Nuclear Information System (INIS)

    Cheever, D.; Ihloff, E.; Kelsey, J.; Kolster, H.; Meitanis, N.; Milner, R.; Shinozaki, A.; Tsentalovich, E.; Zwart, T.; Ziskin, V.; Xiao, Y.; Zhang, C.

    2006-01-01

    A polarized hydrogen/deuterium internal gas target has been constructed and operated at the internal target region of the South Hall Ring (SHR) of the MIT-Bates Linear Accelerator Center to carry out measurements of spin-dependent electron scattering at 850MeV. The target used an Atomic Beam Source (ABS) to inject a flux of highly polarized atoms into a thin-walled, coated storage cell. The polarization of the electron beam was determined using a Compton laser backscattering polarimeter. The target polarization was determined using well-known nuclear reactions. The ABS and storage cell were embedded in the Bates Large Acceptance Toroidal Spectrometer (BLAST), which was used to detect scattered particles from the electron-target interactions. The target has been designed to rapidly (∼8h) switch operation from hydrogen to deuterium. Further, this target was the first to be operated inside a magnetic spectrometer in the presence of a magnetic field exceeding 2kG. An ABS intensity 2.5x10 16 at/s and a high polarization (∼70%) inside the storage cell have been achieved. The details of the target design and construction are described here and the performance over an 18 month period is reported

  7. A 4-PI DILEPTON SPECTROMETER - PEPSI

    NARCIS (Netherlands)

    BUDA, A; BACELAR, JCS; BALANDA, A; VANKLINKEN, J; SUJKOWSKI, Z; VANDERWOUDE, A

    1993-01-01

    A novel positron-electron pair spectroscopy instrument (PEPSI) was designed to measure transitions in the energy region 10-40 MeV. It consists of Nd2Fe14B permanent magnets forming a compact 4 pi magnetic filter consisting of 12 positron and 20 electron mini-orange-like spectrometers. The response

  8. Streaming energetic electrons in earth's magnetotail - Evidence for substorm-associated magnetic reconnection

    Science.gov (United States)

    Bieber, J. W.; Stone, E. C.

    1980-01-01

    This letter reports the results of a systematic study of streaming greater than 200 keV electrons observed in the magnetotail with the Caltech Electron/Isotope Spectrometers aboard IMP-7 and IMP-8. A clear statistical association of streaming events with southward magnetic fields, often of steep inclination, and with substorms as evidenced by the AE index is demonstrated. These results support the interpretation that streaming energetic electrons are indicative of substorm-associated magnetic reconnection in the near-earth plasma sheet.

  9. An achromatic multipassage magnetic mass spectrometer

    International Nuclear Information System (INIS)

    Boulanger, P.; Baril, M.

    1999-01-01

    A design providing achromatic correction to a multipassage magnetic mass spectrometer previously described by the author is presented. The energy spatial dispersion caused by repeated passages in the magnetic prism is corrected by three supplementary mirrors placed in a reinjection loop. From this study one can see that we simultaneously eliminate the energy dispersion term C ΔE/E and the opening angle aberration term C α 2 and we may also eliminate the coupled aberration term C αΔE/E

  10. Accuracy evaluation of a Compton X-ray spectrometer with bremsstrahlung X-rays generated by a 6 MeV electron bunch

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Sadaoki, E-mail: kojima-s@ile.osaka-u.ac.jp; Arikawa, Yasunobu; Zhang, Zhe; Ikenouchi, Takahito; Morace, Alessio; Nagai, Takahiro; Abe, Yuki; Sakata, Shouhei; Inoue, Hiroaki; Utsugi, Masaru; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishimura, Yasuhiko; Togawa, Hiromi [Toyota Technical Development Corporation, 1-21 Imae, Hanamoto-cho, Toyota, Aichi 470-0334 (Japan); Ozaki, Tetsuo [National Institute for Fusion Science, 322-6 Oroshicho, Toki, Gifu 509-5292 (Japan); Kato, Ryukou [The Institute of Science and Industrial Research, Osaka University, 2-6 Yamada-oka, Suita, Osaka (Japan)

    2014-11-15

    A Compton-scattering-based X-ray spectrometer is developed to obtain the energy distribution of fast electrons produced by intense laser and matter interactions. Bremsstrahlung X-rays generated by fast electrons in a material are used to measure fast electrons’ energy distribution in matter. In the Compton X-ray spectrometer, X-rays are converted into recoil electrons by Compton scattering in a converter made from fused silica glass, and a magnet-based electron energy analyzer is used to measure the energy distribution of the electrons that recoil in the direction of the incident X-rays. The spectrum of the incident X-rays is reconstructed from the energy distribution of the recoil electrons. The accuracy of this spectrometer is evaluated using a quasi-monoenergetic 6 MeV electron bunch that emanates from a linear accelerator. An electron bunch is injected into a 1.5 mm thick tungsten plate to produce bremsstrahlung X-rays. The spectrum of these bremsstrahlung X-rays is obtained in the range from 1 to 9 MeV. The energy of the electrons in the bunch is estimated using a Monte Carlo simulation of particle-matter interactions. The result shows that the spectrometer's energy accuracy is ±0.5 MeV for 6.0 MeV electrons.

  11. How to measure energy of LEReC electron beam with magnetic spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Seletskiy, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2016-04-11

    For successful cooling the energies of RHIC ion beam and LEReC electron beam must be matched with 10-4 accuracy. While the energy of ions will be known with required accuracy, e-beam energy can have as large initial offset as 5%. The final setting of e-beam energy will be performed by observing either Schottky spectrum or recombination signal from debunched ions co-traveling with the e-beam. Yet, to start observing such signals one has to set absolute energy of electron beam with accuracy better than 10-2, preferably better than 5∙10-3. The aim of this exercise is to determine whether and how such accuracy can be reached by utilizing LEReC 180° bend as a spectrometer.

  12. A pulse spectrometer for NMR measurements on magnetically ordered materials

    International Nuclear Information System (INIS)

    Englich, J.; Pikner, B.; Sedlak, B.

    1975-01-01

    A simple design of a pulse nuclear magnetic resonance spectrometer is described. The spectrometer permits spin echo measurements on magnetically ordered substances. It operates in the frequency range 10 to 130 MHz, but this basic range can be extended by a replacement of the compact radiofrequency unit. The transmitter gives radiofrequency pulses with an amplitude of up to 1 kV on the coil with the investigated sample. The pulse programmer makes possible relaxation measurements in a time interval of 10 -5 to 10 -1 s. Attention was devoted to obtaining a maximum signal-to-noise ratio in the whole frequency range. Sensitivity of the spectrometer is demonstrated by spin echo measurement on pure iron powder. (author)

  13. A new magnetic spectrometer for the investigation of the internal conversion electron in capture reaction

    International Nuclear Information System (INIS)

    Suarez, A.A.

    1978-01-01

    Planning, development and manufacture of a new beta spectrometer for the investigation of the internal conversion electrons, from 0,02 to 10 MeV, emitted during the radioative capture process of the thermal neutrons. The resolution on the base of resolution curve is about 1,5 X 10 sup(-3) [pt

  14. Scanning electron microscopy-energy dispersive X-ray spectrometer ...

    African Journals Online (AJOL)

    The distribution of arsenic (As) and cadmium (Cd) in himematsutake was analyzed using scanning electron microscopy-energy dispersive X-ray spectrometer (SEM-EDX). The atomic percentage of the metals was confirmed by inductively coupled plasma-mass spectrometer (ICP-MS). Results show that the accumulation of ...

  15. Account of magnetic field effects of polarized proton target on charged particle trajectories in experiments with magnetic spectrometers

    International Nuclear Information System (INIS)

    Telegin, Yu.N.; Ranyuk, Yu.N.; Karnaukhov, I.M.; Lukhanin, A.A.; Sporov, E.A.

    1980-01-01

    Some effects of the influence of magnetic field of a polarized proton target (PPT) on trajectories of secondary particles in experiments using magnetic spectrometers are considered. It is shown that these effects can be eliminated by the target shift relatively to the spectrometer rotation axis and variation of the spectrometer installation angle. Numerical calculations of the correction values were performed for emitted particle momenta of 100-800 MeB/s and working intensity of the H 0 magnetic field H 0 =27 kG. The influence of the PPT magnetic field on the functions of angular and energy resolution in the γp→π + n experiment is investigated. The results obtained can be used in experiments with a polarized proton target

  16. A 4π dilepton spectrometer: PEPSI

    International Nuclear Information System (INIS)

    Buda, A.; Bacelar, J.C.S.; Balanda, A.; Klinken, J. van; Sujkowski, Z.; Woude, A. van der

    1993-01-01

    A novel positron-electron pair spectroscopy instrument (PEPSI) was designed to measure transitions in the energy region 10-40 MeV. It consists of Nd 2 Fe 14 B permanent magnets forming a compact 4π magnetic filter consisting of 12 positron and 20 electron mini-orange-like spectrometers. The response function of PEPSI has been measured with mono-energetic beams of electrons from 5 to 20 MeV. The PEPSI spectrometer was used for measuring the internal pair conversion coefficient (α π ) of the 15.1 MeV M1 transition from a J π =1 + state to the ground state in 12 C. Our experimental value of α π =(3.3±0.5)x10 -3 is in good agreement with theoretical estimates. (orig.)

  17. A 4 π dilepton spectrometer: PEPSI

    Science.gov (United States)

    Buda, A.; Bacelar, J. C. S.; Bałanda, A.; van Klinken, J.; Sujkowski, Z.; van der Woude, A.

    1993-11-01

    A novel positron-electron pair spectroscopy instrument (PEPSI) was designed to measure transitions in the energy region 10-40 MeV. It consists of Nd 2Fe 14B permanent magnets forming a compact 4 π magnetic filter consisting of 12 positron and 20 electron mini-orange-like spectrometers. The response function of PEPSI has been measured with mono-energetic beams of electrons from 5 to 20 MeV. The PEPSI spectrometer was used for measuring the internal pair conversion coefficient ( απ) of the 15.1 MeV M1 transition from a Jπ = 1 + state to the ground state in 12C. Our experimental value of απ = (3.3 ± 0.5) × 10 -3 is in good agreement with theoretical estimates.

  18. Spectrometer for external detection of magnetic and related double resonance

    International Nuclear Information System (INIS)

    Sagalyn, P.L.; Alexander, M.N.

    1977-01-01

    The patent relates to an improvement in nuclear magnetic resonance spectrometer apparatus. It consists of a spectrometer which utilizes separate materials containing, respectively, sample and detector spin systems as opposed to one in which the sample and detector spins are contained in the same single material

  19. Possibilities of magnet prism β-spectrometer application in on-line experiments

    International Nuclear Information System (INIS)

    Akhmetov, K.M.; Arynov, S.

    1996-01-01

    The main attention is paid to works with particle beam in up-to-date nuclear investigations. The application of magnet prism β-spectrometer for works in 'on-line' experiments is considered in this article. The source chamber and detector chamber are distanted from each other on great distance (4 m) and are out of operation field of spectrometer. There is a reliable defence of operating field of device from external parasitic fields by the magnetic screens system. The additional advantage is a factor that source (target) and detector could replacing in specific directions about few centimetres during the device operating. The main β-spectroscopic performances of device are compared with Grenoble spectroscopic complex. The liner depression of prism spectrometer account for from 3,6 up to 6 m; light force - from 2·10 -4 up to 6·10 -4 up to 4π; operating resolving power - 0,02-0,05% by impulse. Investigation range is from several keV up to 3 MeV. There are all opportunities for installing of the on-line magnetic prism spectrometer on the U-150 accelerator and the WWR-K reactor. Spectrometer application in 'on-line' experiments gives possibility to obtain more wide information. 4 refs

  20. Commissioning of the magnetic field in the ATLAS muon spectrometer

    International Nuclear Information System (INIS)

    Arnaud, M.; Bardoux, J.; Bergsma, F.; Bobbink, G.; Bruni, A.; Chevalier, L.; Ennes, P.; Fleischmann, P.; Fontaine, M.; Formica, A.; Gautard, V.; Groenstege, H.; Guyot, C.; Hart, R.; Kozanecki, W.; Iengo, P.; Legendre, M.; Nikitina, T.; Perepelkin, E.; Ponsot, P.

    2008-01-01

    ATLAS is a general-purpose detector at the 14 TeV proton-proton Large Hadron Collider at CERN. The muon spectrometer will operate in the magnetic field provided by a large, eight-coil barrel toroid magnet bracketed by two smaller toroidal end-caps. The toroidal field is non-uniform, with an average value of about 0.5 T in the barrel region, and is monitored using three-dimensional Hall sensors which must be accurate to ∼1 mT. The barrel coils were installed in the cavern from 2004 to 2006, and recently powered up to their nominal current. The Hall-sensor measurements are compared with calculations to validate the magnetic models, and used to reconstruct the position and shape of the coil windings. Field perturbations by the magnetic materials surrounding the muon spectrometer are found in reasonable agreement with finite-element magnetic-field simulations

  1. Commissioning of the magnetic field in the ATLAS muon spectrometer

    CERN Document Server

    Arnaud, M; Bergsma, F; Bobbink, G; Bruni, A; Chevalier, L; Ennes, P; Fleischmann, P; Fontaine, M; Formica, A; Gautard, V; Groenstege, H; Guyot, C; Hart, R; Kozanecki, W; Iengo, P; Legendre, M; Nikitina, T; Perepelkin, E; Ponsot, P; Richardson, A; Vorozhtsov, A; Vorozthsov, S

    2008-01-01

    ATLAS is a general-purpose detector at the 14 TeV proton-proton Large Hadron Collider at CERN. The muon spectrometer will operate in the magnetic field provided by a large, eight-coil barrel toroid magnet bracketed by two smaller toroidal end-caps. The toroidal field is non-uniform, with an average value of about 0.5 T in the barrel region, and is monitored using three-dimensional Hall sensors which must be accurate to 1 mT. The barrel coils were installed in the cavern from 2004 to 2006, and recently powered up to their nominal current. The Hall-sensor measurements are compared with calculations to validate the magnetic models, and used to reconstruct the position and shape of the coil windings. Field perturbations by the magnetic materials surrounding the muon spectrometer are found in reasonable agreement with finite-element magnetic-field simulations.

  2. Computation of the magnetic field of a spectrometer in detectors region

    International Nuclear Information System (INIS)

    Zhidkov, E.P.; Yuldasheva, M.B.; Yudin, I.P.; Yuldashev, O.I.

    1995-01-01

    Computed results of the 3D magnetic field of a spectrometer intended for investigation of hadron production of charmed particles and the indication of the narrow resonances in neutron-nucleus interactions are presented. The methods used in computations: finite element method and finite element method with suggested new infinite elements are described. For accuracy control the computations were carried out on a sequence of three-dimensional meshes. Special attention is devoted to behaviour of the magnetic field in the basic detector (proportional chambers) region. The performed results can be used for the field behaviour estimate of similar spectrometer magnets. (orig.)

  3. A multi-channel THz and infrared spectrometer for femtosecond electron bunch diagnostics by single-shot spectroscopy of coherent radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wesch, Stephan; Schmidt, Bernhard; Behrens, Christopher; Delsim-Hashemi, Hossein; Schmueser, Peter

    2011-08-15

    The high peak current required in free-electron lasers (FELs) is realized by longitudinal compression of the electron bunches to sub-picosecond length. In this paper, a frequency-domain diagnostic method is described that is capable of resolving structures in the femtosecond regime. A novel in-vacuum spectrometer has been developed for spectroscopy of coherent radiation in the THz and infrared range. The spectrometer is equipped with five consecutive dispersion gratings and 120 parallel readout channels; it can be operated either in short wavelength mode (5-44 {mu}m) or in long wavelength mode (45-430 {mu}m). Fast parallel readout permits the spectroscopy of coherent radiation from single electron bunches. Test measurements at the soft X-ray free-electron laser FLASH, using coherent transition radiation, demonstrate excellent performance of the spectrometer. The high sensitivity down to a few micrometers allows study of short bunch features caused for example by microbunching e ects in magnetic chicanes. The device is planned for use as an online bunch profile monitor during regular FEL operation. (orig.)

  4. A multi-channel THz and infrared spectrometer for femtosecond electron bunch diagnostics by single-shot spectroscopy of coherent radiation

    International Nuclear Information System (INIS)

    Wesch, Stephan; Schmidt, Bernhard; Behrens, Christopher; Delsim-Hashemi, Hossein; Schmueser, Peter

    2011-08-01

    The high peak current required in free-electron lasers (FELs) is realized by longitudinal compression of the electron bunches to sub-picosecond length. In this paper, a frequency-domain diagnostic method is described that is capable of resolving structures in the femtosecond regime. A novel in-vacuum spectrometer has been developed for spectroscopy of coherent radiation in the THz and infrared range. The spectrometer is equipped with five consecutive dispersion gratings and 120 parallel readout channels; it can be operated either in short wavelength mode (5-44 μm) or in long wavelength mode (45-430 μm). Fast parallel readout permits the spectroscopy of coherent radiation from single electron bunches. Test measurements at the soft X-ray free-electron laser FLASH, using coherent transition radiation, demonstrate excellent performance of the spectrometer. The high sensitivity down to a few micrometers allows study of short bunch features caused for example by microbunching e ects in magnetic chicanes. The device is planned for use as an online bunch profile monitor during regular FEL operation. (orig.)

  5. What Caused the Lead burn-out in Spectrometer Magnet 2B

    International Nuclear Information System (INIS)

    Green, Michael A.

    2010-01-01

    The spectrometer solenoids are supposed to be the first magnets installed in the MICE Cooling Channel. The results of the test of Spectrometer Magnet 2B are reported in a previous MICE Note. Magnet 2B was tested with all five coils connected in series. The magnet failed because a lead to coil M2 failed before it could be trained to its full design current of 275 A. First, this report describes the condition of the magnet when the lead failure occurred. The lead that failed was between the cold mass feed-through and the heavy lead that connected to coil M2 and the quench protection diodes. It is believed that the lead failed because the minimum propagation zone (MPZ) length was too short. The quench was probably triggered by lead motion in the field external to the magnet center coil. The effect of heat transfer on quench propagation and MPZ length is discussed. The MPZ length is compared for a number of cases that apply to the spectrometer solenoid 2B as built and as it has been repaired. The required heat transfer coefficient for cryogenic stability and the quench propagation velocity along the leads are compared for various parts of the Magnet leads inside the cold mass cryostat. The effect of the insulation on leads on heat transfer is and stability is discussed.

  6. Design and construction of a magnetic sector mass spectrometer

    International Nuclear Information System (INIS)

    Dallaqua, R.S.; Ludwig, G.O.; Montes, A.

    1991-08-01

    In this work we describe the design and construction of a sector magnetic mass spectrometer. The main parts of the instrument are: ion source, grids (extraction, energy analysis and ion acceleration), electrostatic lens, magnetic sector and detector. All these components are kept inside a vacuum chamber evacuated by a turbomolecular pump. (author)

  7. Computation of the Magnetic Field of a Spectrometer in Detectors Region

    International Nuclear Information System (INIS)

    Zhidkov, E.P.; Yuldasheva, M.B.; Yudin, I.P.; Yuldashev, O.I.

    1994-01-01

    Computed results of the 3D magnetic field of a spectrometer intended for investigation of hadron production of charmed particles and the indication of the narrow resonances in neutron-nucleus interaction are presented. The methods, used in computations - finite element method and finite element method with suggested new infinite elements are described. For accuracy control the computations were carried out on a sequence of three-dimensional meshes. Special attention is devoted to the behaviour of the magnetic field in the basic detectors (proportional chambers) region. The performed results can be used for the field behaviour estimate of similar spectrometer magnets. 12 refs., 16 figs

  8. Design of a large superconducting spectrometer magnet

    International Nuclear Information System (INIS)

    Shintomi, T.; Makida, Y.; Mito, T.; Yamanoi, Y.; Hashimito, O.; Nagae, T.

    1989-04-01

    The superconducting spectrometer magnet for nuclear physics experiments has been under construction by Institute for Nuclear Study, University of Tokyo with collaboration from KEK. The magnet has a sector type coil. The magnetic field is 3 T with the magnet gap of 50 cm and the stored energy is 11.8 MJ. The easy operation and maintenance are taken into consideration in addition to usual design concept. Three dimensional magnetic field calculation and the stress analysis have been performed. The code 'QUENCH' was applied to decide the operation current and to check the safety of the coil. As a result, the current of 500 A was selected. The heat leaks were checked and estimated less than 2 W at 4 K. A small refrigerator is to be used for thermal insulations at 80 and 20 K. (author)

  9. High-resolution compact Johann crystal spectrometer with the Livermore electron beam ion trap

    International Nuclear Information System (INIS)

    Robbins, D.L.; Chen, H.; Beiersdorfer, P.; Faenov, A.Ya.; Pikuz, T.A.; May, M.J.; Dunn, J.; Smith, A.J.

    2004-01-01

    A compact high-resolution (λ/Δλ≅10 000) spherically bent crystal spectrometer in the Johann geometry was recently installed and tested on the Lawrence Livermore National Laboratory SuperEBIT electron beam ion trap. The curvature of the mica (002) crystal grating allows for higher collection efficiency compared to the flat and cylindrically bent crystal spectrometers commonly used on the Livermore electron beam ion traps. The spectrometer's Johann configuration enables orientation of its dispersion plane to be parallel to the electron beam propagation. Used in concert with a crystal spectrometer, whose dispersion plane is perpendicular to the electron beam propagation, the polarization of x-ray emission lines can be measured

  10. Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

    NARCIS (Netherlands)

    Erni, W.; Keshelashvili, I; Krusche, B.

    2009-01-01

    This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible

  11. Design of combined magnetic field system for magnetic-bottle time-of-flight spectrometer

    International Nuclear Information System (INIS)

    Wang Chao; Tian Jinshou; Zhang Meizhi; Kang Yifan

    2011-01-01

    Based on the primary requirement for the magnetic field system in magnetic-bottle time-of-flight spectrometer, an appropriate combined inhomogeneous magnetic field system is designed. The inhomogeneous higher magnetic field part, with the highest field of 1.2 T, is produced by the combination of a permanent magnet and a pole piece with optimized shape. The magnet,known as NdFeB magnet,is one of rare earth permanent magnets in N52. The guiding uniform magnetic field of 1.0 x 10 -3 T is provided by solenoid, with length of 3 m and radius of 3 cm. The pitch between the pole piece and the near end of used solenoid is determined to be 5 cm, which can satisfy the actual engineering needs. (authors)

  12. Study and realization of a detection apparatus for the Grenoble magnetic spectrometer

    International Nuclear Information System (INIS)

    Burel, J.-P.

    1975-01-01

    Two multiwire proportional chambers were studied for a magnetic spectrometer. The first one is constructed for visualization of the attenuated beam at the place of the target. The sensitive area is 4x4cm 2 . The anode wires are 0.020mm diameter, gold plated tungsten, 2mm spaced. Each cathode plane wires are connected to a 20 units-5ns delay line. The planes are 3.2mm spaced. The spatial resolution obtained is better than 0.3mm. The second chamber is placed at the focal plane of the spectrometer. The sensitive area is 50x5cm 2 . The horizontal position detection uses an original charge-division system with four chains of capacitors. The particle position results of the center of gravity calculus of different amplified pulses. An electronic circuit has been constructed and the result is directly stored in a memory unit. The spatial resolution obtained is 0.4mm [fr

  13. Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

    CERN Document Server

    Erni, W; Krusche, B; Steinacher, M; Heng, Y; Liu, Z; Liu, H; Shen, X; Wang, O; Xu, H; Becker, J; Feldbauer, F; Heinsius, F -H; Held, T; Koch, H; Kopf, B; Pelizaeus, M; Schröder, T; Steinke, M; Wiedner, U; Zhong, J; Bianconi, A; Bragadireanu, M; Pantea, D; Tudorache, A; Tudorache, V; De Napoli, M; Giacoppo, F; Raciti, G; Rapisarda, E; Sfienti, C; Bialkowski, E; Budzanowski, A; Czech, B; Kistryn, M; Kliczewski, S; Kozela, A; Kulessa, P; Pysz, K; Schäfer, W; Siudak, R; Szczurek, A; zycki, W Czy; Domagala, M; Hawryluk, M; Lisowski, E; Lisowski, F; Wojnar, L; Gil, D; Hawranek, P; Kamys, B; Kistryn, St; Korcyl, K; Krzemien, W; Magiera, A; Moskal, P; Rudy, Z; Salabura, P; Smyrski, J; Wronska, A; Al-Turany, M; Augustin, I; Deppe, H; Flemming, H; Gerl, J; Goetzen, K; Hohler, R; Lehmann, D; Lewandowski, B; Lühning, J; Maas, F; Mishra, D; Orth, H; Peters, K; Saitô, T; Schepers, G; Schmidt, C J; Schmitt, L; Schwarz, C; Voss, B; Wieczorek, P; Wilms, A; Brinkmann, K -T; Freiesleben, H; Jaekel, R; Kliemt, R; Wuerschig, T; Zaunick, H -G; Abazov, V M; Alexeev, G; Arefev, A; Astakhov, V I; Barabanov, M Yu; Batyunya, B V; Davydov, Yu I; Dodokhov, V Kh; Efremov, A A; Fedunov, A G; Feshchenko, A A; Galoyan, A S; Grigorian, S; Karmokov, A; Koshurnikov, E K; Kudaev, V Ch; Lobanov, V I; Lobanov, Yu Yu; Makarov, A F; Malinina, L V; Malyshev, V L; Mustafaev, G A; Olshevski, A; Pasyuk, M A; Perevalova, E A; Piskun, A A; Pocheptsov, T A; Pontecorvo, G; Rodionov, V K; Rogov, Yu N; Salmin, R A; Samartsev, A G; Sapozhnikov, M G; Shabratova, A; Shabratova, G S; Skachkova, A N; Skachkov, N B; Strokovsky, E A; Suleimanov, M K; Teshev, R Sh; Tokmenin, V V; Uzhinsky, V V; Vodopyanov, A S; Zaporozhets, S A; Zhuravlev, N I; Zorin, A G; Branford, D; Föhl, K; Glazier, D; Watts, D; Woods, P; Eyrich, W; Lehmann, A; Teufel, A; Dobbs, S; Metreveli, Z; Seth, K; Tann, B; Tomaradze, A G; Bettoni, D; Carassiti, V; Cecchi, A; Dalpiaz, P; Fioravanti, E; Garzia, I; Negrini, M; Savri`e, M; Stancari, G; Dulach, B; Gianotti, P; Guaraldo, C; Lucherini, V; Pace, E; Bersani, A; Macri, M; Marinelli, M; Parodi, R F; Brodski, I; Döring, W; Drexler, P; Düren, M; Gagyi-Palffy, Z; Hayrapetyan, A; Kotulla, M; Kühn, W; Lange, S; Liu, M; Metag, V; Nanova, M; Novotny, R; Salz, C; Schneider, J; Schoenmeier, P; Schubert, R; Spataro, S; Stenzel, H; Strackbein, C; Thiel, M; Thoering, U; Yang, S; Clarkson, T; Cowie, E; Downie, E; Hill, G; Hoek, M; Ireland, D; Kaiser, R; Keri, T; Lehmann, I; Livingston, K; Lumsden, S; MacGregor, D; McKinnon, B; Murray, M; Protopopescu, D; Rosner, G; Seitz, B; Yang, G; Babai, M; Biegun, A K; Bubak, A; Guliyev, E; Jothi, V S; Kavatsyuk, M; Löhner, H; Messchendorp, J; Smit, H; van der Weele, J C; García, F; Riska, D -O; Büscher, M; Dosdall, R; Dzhygadlo, R; Gillitzer, A; Grunwald, D; Jha, V; Kemmerling, G; Kleines, H; Lehrach, A; Maier, R; Mertens, M; Ohm, H; Prasuhn, D; Randriamalala, T; Ritman, J; Roeder, M; Stockmanns, T; Wintz, P; Wüstner, P; Kisiel, J; Li, S; Li, Z; Sun, Z; Xu, H; Fissum, S; Hansen, K; Isaksson, L; Lundin, M; Schröder, B; Achenbach, P; Espi, M C Mora; Pochodzalla, J; Sanchez, S; Sanchez-Lorente, A; Dormenev, V I; Fedorov, A A; Korzhik, M V; Missevitch, O V; Balanutsa, V; Chernetsky, V; Demekhin, A; Dolgolenko, A; Fedorets, P; Gerasimov, A; Goryachev, V; Boukharov, A; Malyshev, O; Marishev, I; Semenov, A; Hoeppner, C; Ketzer, B; Konorov, I; Mann, A; Neubert, S; Paul, S; Weitzel, Q; Khoukaz, A; Rausmann, T; Täschner, A; Wessels, J; Varma, R; Baldin, E; Kotov, K; Peleganchuk, S; Tikhonov, Yu; Boucher, J; Hennino, T; Kunne, R; Ong, S; Pouthas, J; Ramstein, B; Rosier, P; Sudol, M; Van de Wiele, J; Zerguerras, T; Dmowski, K; Korzeniewski, R; Przemyslaw, D; Slowinski, B; Boca, G; Braghieri, A; Costanza, S; Fontana, A; Genova, P; Lavezzi, L; Montagna, P; Rotondi, A; Belikov, N I; Davidenko, A M; Derevshchikov, A A; Goncharenko, Yu M; Grishin, V N; Kachanov, V A; Konstantinov, D A; Kormilitsin, V A; Kravtsov, V I; Matulenko, Yu A; Melnik, Y M; Meshchanin, A P; Minaev, N G; Mochalov, V V; Morozov, D A; Nogach, L V; Nurushev, S B; Ryazantsev, A V; Semenov, P A; Soloviev, L F; Uzunian, A V; Vasilev, A N; Yakutin, A E; Baeck, T; Cederwall, B; Bargholtz, C; Geren, L; Tegnér, P E; Belostotskii, S; Gavrilov, G; Itzotov, A; Kiselev, A; Kravchenko, P; Manaenkov, S; Miklukho, O; Naryshkin, Yu; Veretennikov, D; Vikhrov, V; Zhadanov, A; Fava, L; Panzieri, D; Alberto, D; Amoroso, A; Botta, E; Bressani, T; Bufalino, S; Bussa, M P; Busso, L; De Mori, F; Destefanis, M; Ferrero, L; Grasso, A; Greco, M; Kugathasan, T; Maggiora, M; Marcello, S; Serbanut, G; Sosio, S; Bertini, R; Calvo, D; Coli, S; De Remigis, P; Feliciello, A; Filippi, A; Giraudo, G; Mazza, G; Rivetti, A; Szymanska, K; Tosello, F; Wheadon, R; Morra, O; Agnello, M; Iazzi, F; Szymanska, K; Birsa, R; Bradamante, F; Bressan, A; Martin, A; Clement, H; Ekström, C; Calén, H; Grape, S; Hoeistad, B; Johansson, T; Kupsc, A; Marciniewski, P; Thomé, E; Zlomanczuk, Yu; Díaz, J; Ortiz, A; Borsuk, S; Chlopik, A; Guzik, Z; Kopec, J; Kozlovskii, T; Melnychuk, D; Plominski, M; Szewinski, J; Traczyk, K; Zwieglinski, B; Bühler, P; Gruber, A; Kienle, P; Marton, J; Widmann, E; Zmeskal, J

    2009-01-01

    This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.

  14. The VESUVIO electron volt neutron spectrometer

    Science.gov (United States)

    Mayers, J.; Reiter, G.

    2012-04-01

    This paper describes the VESUVIO electron volt neutron spectrometer at the ISIS pulsed neutron source and its data analysis routines. VESUVIO is used primarily for the measurement of proton momentum distributions in condensed matter systems, but can also be used to measure the kinetic energies of heavier masses and bulk in-situ sample compositions. A series of VESUVIO runs on the same zirconium hydride sample over the past two years show that (1) kinetic energies of protons can be measured to an absolute accuracy of ˜1%. (2) Measurements of the proton momentum distribution n(p) are highly reproducible from run to run. This shows that small changes in kinetic energy and the detailed shape of n(p) with parameters such as temperature, pressure and sample composition can be reliably extracted from VESUVIO data. (3) The impulse approximation (IA) is well satisfied on VESUVIO. (4) The small deviations from the IA due to the finite momentum transfer of measurement are well understood. (5) There is an anomaly in the magnitude of the inelastic neutron cross-section of the protons in zirconium hydride, with an observed reduction of 10% ± 0.3% from that given in standard tables. This anomaly is independent of energy transfer to within experimental error. Future instrument developments are discussed. These would allow the measurement of n(p) in other light atoms, D, 3He, 4He, Li, C and O and measurement of eV electronic and magnetic excitations.

  15. The VESUVIO electron volt neutron spectrometer

    International Nuclear Information System (INIS)

    Mayers, J; Reiter, G

    2012-01-01

    This paper describes the VESUVIO electron volt neutron spectrometer at the ISIS pulsed neutron source and its data analysis routines. VESUVIO is used primarily for the measurement of proton momentum distributions in condensed matter systems, but can also be used to measure the kinetic energies of heavier masses and bulk in-situ sample compositions. A series of VESUVIO runs on the same zirconium hydride sample over the past two years show that (1) kinetic energies of protons can be measured to an absolute accuracy of ∼1%. (2) Measurements of the proton momentum distribution n(p) are highly reproducible from run to run. This shows that small changes in kinetic energy and the detailed shape of n(p) with parameters such as temperature, pressure and sample composition can be reliably extracted from VESUVIO data. (3) The impulse approximation (IA) is well satisfied on VESUVIO. (4) The small deviations from the IA due to the finite momentum transfer of measurement are well understood. (5) There is an anomaly in the magnitude of the inelastic neutron cross-section of the protons in zirconium hydride, with an observed reduction of 10% ± 0.3% from that given in standard tables. This anomaly is independent of energy transfer to within experimental error. Future instrument developments are discussed. These would allow the measurement of n(p) in other light atoms, D, 3 He, 4 He, Li, C and O and measurement of eV electronic and magnetic excitations. (paper)

  16. Performance of the electron energy-loss spectrometer

    International Nuclear Information System (INIS)

    Tanaka, H.; Huebner, R.H.

    1977-01-01

    Performance characteristics of the electron energy-loss spectrometer incorporating a new high-resolution hemispherical monochromator are reported. The apparatus achieved an energy-resolution of 25 meV in the elastic scattering mode, and angular distributions of elastically scattered electrons were in excellent agreement with previous workers. Preliminary energy-loss spectra for several atmospheric gases demonstrate the excellent versatility and stable operation of the improved system. 12 references

  17. Charged-particle magnetic-quadrupole spectrometer for neutron induced reactions

    International Nuclear Information System (INIS)

    Haight, R.C.; Grimes, S.M.; Tuckey, B.J.; Anderson, J.D.

    1975-01-01

    A spectrometer has been developed for measuring the charged particle production cross sections and spectra in neutron-induced reactions. The spectrometer consists of a magnetic quadrupole doublet which focuses the charged particles onto a silicon surface barrier detector telescope which is 2 meters or more from the irradiated sample. Collimators, shielding, and the large source-to-detector distance reduce the background enough to use the spectrometer with a 14-MeV neutron source producing 4 . 10 12 n/s. The spectrometer has been used in investigations of proton, deuteron, and alpha particle production by 14-MeV neutrons incident on various materials. Protons with energies as low as 1.1 MeV have been measured. The good resolution of the detectors has also made possible an improved measurement of the neutron- neutron scattering length from the 0 0 proton spectrum from deuteron breakup by 14-MeV neutrons

  18. Development of a mini-orange spectrometer for conversion electron study

    International Nuclear Information System (INIS)

    Mishra, N.R.; Chakravarty, V.; Chintalapudi, S.N.; Ghugre, S.S.; Sastry, D.L.

    1996-01-01

    Conversion electrons provide with an unique tool to have an unambiguous multipolarity assignment for the observed gamma transitions. The fabrication of an electron spectrometer to detect these conversion electrons is a non-trivial task

  19. The Alpha Magnetic Spectrometer Silicon Tracker

    CERN Document Server

    Burger, W J

    1999-01-01

    The Alpha Magnetic Spectrometer (AMS) is designed as a independent module for installation on the International Space Station Alpha (ISSA) in the year 2002 for an operational period of three years. The principal scientific objectives are the searches for antimatter and dark matter in cosmic rays. The AMS uses 5.5 m sup 2 of silicon microstrip sensors to reconstruct charged particle trajectories in the field of a permanent magnet. The detector design and construction covered a 3 yr period which terminated with a test flight on the NASA space shuttle Discovery during June 2-12, 1988. In this contribution, we describe the shuttle version of the AMS silicon tracker, including preliminary results of the tracker performance during the flight. (author)

  20. Some characteristics of the superconducting magnetic system of toroidal spectrometer STORS

    International Nuclear Information System (INIS)

    Andreev, S.V.; Vorozhtsov, S.B.; Kakurin, S.I.

    1993-01-01

    A superconducting toroidal spectrometer (STORS) has been suggested to provide precision measurements of structure functions in muon beams. In this paper we present the calculation of the magnet induction and forces influencing the elements of the magnet, requirements to the reliability and rigidity of the carrying elements of the magnet construction. (author.) 14 refs.; 50 figs.; 4 tabs

  1. Calibration of a compact magnetic proton recoil neutron spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jianfu, E-mail: zhang_jianfu@163.com [School of Nuclear Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Ouyang, Xiaoping; Zhang, Xianpeng [School of Nuclear Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Ruan, Jinlu [Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Zhang, Guoguang [Applied Institute of Nuclear Technology, China Institute of Atomic Energy, Beijing 102413 (China); Zhang, Xiaodong [Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Qiu, Suizheng, E-mail: szqiu@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Chen, Liang; Liu, Jinliang; Song, Jiwen; Liu, Linyue; Yang, Shaohua [Northwest Institute of Nuclear Technology, Xi' an 710024 (China)

    2016-04-21

    Magnetic proton recoil (MPR) neutron spectrometer is considered as a powerful instrument to measure deuterium–tritium (DT) neutron spectrum, as it is currently used in inertial confinement fusion facilities and large Tokamak devices. The energy resolution (ER) and neutron detection efficiency (NDE) are the two most important parameters to characterize a neutron spectrometer. In this work, the ER calibration for the MPR spectrometer was performed by using the HI-13 tandem accelerator at China Institute of Atomic Energy (CIAE), and the NDE calibration was performed by using the neutron generator at CIAE. The specific calibration techniques used in this work and the associated accuracies were discussed in details in this paper. The calibration results were presented along with Monte Carlo simulation results.

  2. The calibration of spectrometers for Auger electron and X-ray photoelectron spectrometers part II - the determination of the electron spectrometer transmission function and the detector sensitivity energy dependencies

    International Nuclear Information System (INIS)

    Smith, G.C.; Seah, M.P.

    1991-01-01

    For the use of published general or theoretical sensitivity factors in quantitative AES and XPS the energy dependence of both the spectrometer transmission function and the detector sensitivity must be known. Here we develop simple procedures which allow these dependencies to be determined experimentally. Detailed measurements for a modified VG Scientific ESCALAB II, the metrology spectrometer, operated in both the constant ΔE/E and constant ΔE modes, are presented and compared with theoretical estimates. It is shown that an exceptionally detailed electron-optical calculation, involving proprietary information, would be required to match the accuracy of the experimental procedures developed. Removal of the spectrometer transmission function and the detector sensitivity terms allows the measured spectrum to be converted to the true electron emission spectrum irrespective of the mode of operation. This provides the first step to the provision of reference samples to calibrate the transmission functions and detector sensitivities of all instruments so that they, in turn, may produce true electron emission spectra. This is vital if (i) all instruments are to give consistent results, (ii) theoretical terms are to be used in quantifying either AES or XPS and (iii) reference data banks are to be established for AES or XPS

  3. A low-cost spectrometer for NMR measurements in the Earth's magnetic field

    International Nuclear Information System (INIS)

    Michal, Carl A

    2010-01-01

    We describe and demonstrate an inexpensive, easy-to-build, portable spectrometer for nuclear magnetic resonance measurements in the Earth's magnetic field. The spectrometer is based upon a widely available inexpensive microcontroller, which acts as a pulse programmer, audio-frequency synthesizer and digitizer, replacing what are typically the most expensive specialized components of the system. The microcontroller provides the capability to execute arbitrarily long and complicated sequences of phase-coherent, phase-modulated excitation pulses and acquire data sets of unlimited duration. Suitably packaged, the spectrometer is amenable to measurements in the research lab, in the field or in the teaching lab. The choice of components was heavily weighted by cost and availability, but required no significant sacrifice in performance. Using an existing personal computer, the resulting design can be assembled for as little as US$200. The spectrometer performance is demonstrated with spin-echo and Carr–Purcell–Meiboom–Gill pulse sequences on a water sample

  4. A low-cost spectrometer for NMR measurements in the Earth's magnetic field

    Science.gov (United States)

    Michal, Carl A.

    2010-10-01

    We describe and demonstrate an inexpensive, easy-to-build, portable spectrometer for nuclear magnetic resonance measurements in the Earth's magnetic field. The spectrometer is based upon a widely available inexpensive microcontroller, which acts as a pulse programmer, audio-frequency synthesizer and digitizer, replacing what are typically the most expensive specialized components of the system. The microcontroller provides the capability to execute arbitrarily long and complicated sequences of phase-coherent, phase-modulated excitation pulses and acquire data sets of unlimited duration. Suitably packaged, the spectrometer is amenable to measurements in the research lab, in the field or in the teaching lab. The choice of components was heavily weighted by cost and availability, but required no significant sacrifice in performance. Using an existing personal computer, the resulting design can be assembled for as little as US200. The spectrometer performance is demonstrated with spin-echo and Carr-Purcell-Meiboom-Gill pulse sequences on a water sample.

  5. Investigating electron spin resonance spectroscopy of a spin-½ compound in a home-built spectrometer

    Science.gov (United States)

    Sarkar, Jit; Roy, Subhadip; Singh, Jitendra Kumar; Singh, Sourabh; Chakraborty, Tanmoy; Mitra, Chiranjib

    2018-05-01

    In this work we report electron spin resonance (ESR) measurements performed on NH4CuPO4.H2O, a Heisenberg spin ½ dimer compound. We carried out the experiments both at room temperature and at 78 K, which are well above the antiferromagnetic ordering temperature of the system where the paramagnetic spins have a dominant role in determining its magnetic behavior. We performed the measurements in a home built custom designed continuous wave electron spin resonance (CW-ESR) spectrometer. By analyzing the experimental data, we were able to quantify the Landé g-factor and the ESR line-width of the sample.

  6. New approach to determine the angular transmission in zero-degree magnetic spectrometers

    International Nuclear Information System (INIS)

    Benlliure, J.; Pereira-Conca, J.; Schmidt, K.H.

    2000-11-01

    A new method to estimate the angular transmission in zero-degree magnetic spectrometers is presented. This method is based on a parameterisation of the angular aperture of the spectrometer for any possible value of the magnetic rigidity of the transmitted particles. This parameterisation of the angular aperture together with a description of the kinematics of the reaction mechanism allows to determine the angular transmission analytically, avoiding tedious Monte-Carlo calculations. The analytical solutions are implemented for residual nuclei produced in fission, projectile-fragmentation and fusion-evaporation reactions. (orig.)

  7. Background reduction of the KATRIN spectrometers. Transmission function of the pre-spectrometer and systematic tests of the main-spectrometer wire electrode

    Energy Technology Data Exchange (ETDEWEB)

    Prall, Matthias

    2011-07-04

    The KArlsruhe TRItium Neutrino experiment, KATRIN will determine the mass of the anti {nu}{sub e} with a sensitivity of 0.2 eV (90% C.L.) via a measurement of the {beta}-spectrum of tritium decaying in a windowless gaseous molecular tritium source near its endpoint of 18.57 keV. This approach relies exclusively on the relativistic kinematics of the decay products rendering the experiment model independent and reducing the systematic uncertainty. An ultra-low background of a few mHz and an energy resolution of 0.93 eV are among the requirements to reach the sensitivity. These demands are fulfilled with the main spectrometer (MS). While the {beta}-decay electrons are guided by a magnetic field through the experiment, the MS acts as a high-pass filter for the {beta}-decay electrons. Only those above an energy barrier, the retarding potential, are transmitted to the detector. The last about 30 eV of the T{sub 2} {beta}-spectrum will be scanned in this way. The MS is equipped with a 650 m{sup 2}, two-layered, UHV compatible and quasi-massless wire electrode suppressing secondary electron background originating at the main-spectrometer walls and caused by residual radioactivity and cosmic muons. Its energy resolution of 0.93 eV is only achieved, if a large part of the 248 wire electrode modules, which determine the electric field inside the MS, has a mechanical precision of 0.2 mm. Not a single of the about 28.000 wires of the electrode must break during the lifetime of KATRIN. A 2-dimensional laser sensor for contact-less position (precision about 0.01 mm) and tension (precision about 0.04 N) measurements was developed and applied, to firstly, verify the mechanical precision of the electrode modules and secondly, to examine their reliability. A 3-dimensional coordinate measurement table was automated to perform these measurements in a clean room. This table was also used to verify the precision of components using a camera system and image recognition methods (0.05 mm

  8. Assessment of Alphamagnetic Spectrometer (AMS) Upper Experiment Structural Configuration Shielding Effectiveness Associated with Change from Cryo-Cooled Magnet to Permanent Magnet

    Science.gov (United States)

    Scully, Robert

    2012-01-01

    In the spring of 2010, the Alpha Magnetic Spectrometer 2 (AMS-02) underwent a series of system level electromagnetic interference control measurements, followed by thermal vacuum testing. Shortly after completion of the thermal vacuum testing, the project decided to remove the cryogenically cooled superconducting magnet, and replace it with the original permanent magnet design employed in the earlier AMS- 01 assembly. Doing so necessitated several structural changes, as well as removal or modification of numerous electronic and thermal control devices and systems. At this stage, the project was rapidly approaching key milestone dates for hardware completion and delivery for launch, and had little time for additional testing or assessment of any impact to the electromagnetic signature of the AMS-02. Therefore, an analytical assessment of the radiated emissions behavioural changes associated with the system changes was requested.

  9. The Alpha Magnetic Spectrometer (AMS)

    International Nuclear Information System (INIS)

    Alcaraz, J.; Alpat, B.; Ambrosi, G.; Anderhub, H.; Ao, L.; Arefiev, A.; Azzarello, P.; Babucci, E.; Baldini, L.; Basile, M.; Barancourt, D.; Barao, F.; Barbier, G.; Barreira, G.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba, L.; Bene, P.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.; Bizzaglia, S.; Blasko, S.; Boella, G.; Boschini, M.; Bourquin, M.; Brocco, L.; Bruni, G.; Buenerd, M.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Camps, C.; Cannarsa, P.; Capell, M.; Casadei, D.; Casaus, J.; Castellini, G.; Cecchi, C.; Chang, Y.H.; Chen, H.F.; Chen, H.S.; Chen, Z.G.; Chernoplekov, N.A.; Chiueh, T.H.; Chuang, Y.L.; Cindolo, F.; Commichau, V.; Contin, A.; Crespo, P.; Cristinziani, M.; Cunha, J.P. da; Dai, T.S.; Deus, J.D.; Dinu, N.; Djambazov, L.; DAntone, I.; Dong, Z.R.; Emonet, P.; Engelberg, J.; Eppling, F.J.; Eronen, T.; Esposito, G.; Extermann, P.; Favier, J.; Fiandrini, E.; Fisher, P.H.; Fluegge, G.; Fouque, N.; Galaktionov, Yu.; Gervasi, M.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W.Q.; Hangarter, K.; Hasan, A.; Hermel, V.; Hofer, H.; Huang, M.A.; Hungerford, W.; Ionica, M.; Ionica, R.; Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney, G.; Kenny, J.; Kim, W.; Klimentov, A.; Kossakowski, R.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen, T.; Lamanna, G.; Laurenti, G.; Lebedev, A.; Lee, S.C.; Levi, G.; Levtchenko, P.; Liu, C.L.; Liu, H.T.; Lopes, I.; Lu, G.; Lu, Y.S.; Luebelsmeyer, K.; Luckey, D.; Lustermann, W.; Mana, C.; Margotti, A.; Mayet, F.; McNeil, R.R.; Meillon, B.; Menichelli, M.; Mihul, A.; Mourao, A.; Mujunen, A.; Palmonari, F.; Papi, A.; Park, I.H.; Pauluzzi, M.; Pauss, F.; Perrin, E.; Pesci, A.; Pevsner, A.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Postolache, V.; Produit, N.; Rancoita, P.G.; Rapin, D.; Raupach, F.; Ren, D.; Ren, Z.; Ribordy, M.; Richeux, J.P.; Riihonen, E.; Ritakari, J.; Roeser, U.; Roissin, C.; Sagdeev, R.; Sartorelli, G.; Schultz von Dratzig, A.; Schwering, G.; Scolieri, G.; Seo, E.S.; Shoutko, V.; Shoumilov, E.; Siedling, R.; Son, D.; Song, T.; Steuer, M.; Sun, G.S.; Suter, H.; Tang, X.W.; Ting, S.C.C.Samuel C.C.; Ting, S.M.; Tornikoski, M.; Torsti, J.; Tr umper, J.; Ulbricht, J.; Urpo, S.; Usoskin, I.; Valtonen, E.; Vandenhirtz, J.; Velcea, F.; Velikhov, E.; Verlaat, B.; Vetlitsky, I.; Vezzu, F.; Vialle, J.P.; Viertel, G.; Vite, D.; Gunten, H. Von; Wicki, S.W.S. Waldmeier; Wallraff, W.; Wang, B.C.; Wang, J.Z.; Wang, Y.H.; Wiik, K.; Williams, C.; Wu, S.X.; Xia, P.C.; Yan, J.L.; Yan, L.G.; Yang, C.G.; Yang, M.; Ye, S.W.; Yeh, P.; Xu, Z.Z.; Zhang, H.Y.; Zhang, Z.P.; Zhao, D.X.; Zhu, G.Y.; Zhu, W.Z.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.

    2002-01-01

    The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m 2 ) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A 'scaled-down' version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS

  10. Data Acquisition System for Electron Energy Loss Coincident Spectrometers

    International Nuclear Information System (INIS)

    Zhang Chi; Yu Xiaoqi; Yang Tao

    2005-01-01

    A Data Acquisition System (DAQ) for electron energy loss coincident spectrometers (EELCS) has been developed. The system is composed of a Multiplex Time-Digital Converter (TDC) that measures the flying time of positive and negative ions and a one-dimension position-sensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out (FIFO) memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown

  11. The lead-glass electromagnetic calorimeters for the magnetic spectrometers in Hall C at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Mkrtchyan, H. [A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan 0036 (Armenia); Carlini, R. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Tadevosyan, V., E-mail: tadevosn@jlab.org [A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan 0036 (Armenia); Arrington, J. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Asaturyan, A. [A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan 0036 (Armenia); Christy, M.E. [Hampton University, Hampton, VA 23668 (United States); Dutta, D. [Triangle Universities Nuclear Laboratory and Duke University, Durham, NC 27708 (United States); Ent, R.; Fenker, H.C.; Gaskell, D. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Horn, T. [Catholic University of America, Washington, DC 20064 (United States); Jones, M.K. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Keppel, C.E. [Hampton University, Hampton, VA 23668 (United States); Mack, D.J. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Malace, S.P. [Triangle Universities Nuclear Laboratory and Duke University, Durham, NC 27708 (United States); Mkrtchyan, A. [A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan 0036 (Armenia); Niculescu, M.I. [James Madison University, Harrisonburg, VA 22807 (United States); Seely, J. [Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, MA (United States); Tvaskis, V. [Hampton University, Hampton, VA 23668 (United States); Wood, S.A. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); and others

    2013-08-11

    The electromagnetic calorimeters of the various magnetic spectrometers in Hall C at Jefferson Lab are presented. For the existing High Momentum Spectrometer (HMS) and Short Orbit Spectrometer (SOS), design considerations, relevant construction information, and comparisons of simulated and experimental results are included. The energy resolution of the HMS and SOS calorimeters is better than σ/E∼6%/√(E) and pion/electron (π/e) separation of about 100:1 has been achieved in the energy range of 1–5 GeV. Good agreement has been observed between the experimental and simulated energy resolutions, but simulations systematically exceed experimentally determined π{sup −} suppression factors by close to a factor of two. For the Super High Momentum Spectrometer (SHMS), presently under construction, details on the design and accompanying GEANT4 simulation efforts are given. The anticipated performance of the new calorimeter is predicted over the full momentum range of the SHMS. Good electron/hadron separation is anticipated by combining the energy deposited in an initial (preshower) calorimeter layer with the total energy deposited in the calorimeter. -- Highlights: • Construction and performance of lead glass calorimeters in JLab/Hall C are presented. • ∼5%/√(E) resolution, ∼100:1π/e separation is achieved in HMS calorimeter in GeV range. • Simulated resolution of the HMS calorimeter is in good agreement with experiment. • Simulated pion suppression of the HMS calorimeter exceeds experiment, by less than 2. • Pion suppression of ∼400:1 is predicted in projected SHMS calorimeter by simulations.

  12. Electron optics development for photo-electron spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Wannberg, Bjoern [VG Scienta AB, P.O. Box 15120, SE-750 15 Uppsala (Sweden); BW Particle Optics AB, P.O. Box 55, SE-822 22 Alfta (Sweden)], E-mail: bjorn@particleoptics.se

    2009-03-21

    The demand for simultaneous observation of photo-electron distributions in several dimensions has made the hemispherical deflection analyzer (HDA) and the time-of-flight (TOF) analyzer the dominating spectrometer types. Some common limiting factors for resolution and sensitivity are considered. Recent developments of the HDA and its lens system which increase the energy range and angular acceptance are described. The properties of a recently developed angle-resolving TOF system (AR-TOF) are also described. The possibility to avoid integration losses in energy or angular resolution by applying non-linear mappings of the primary data is discussed.

  13. Electron optics development for photo-electron spectrometers

    International Nuclear Information System (INIS)

    Wannberg, Bjoern

    2009-01-01

    The demand for simultaneous observation of photo-electron distributions in several dimensions has made the hemispherical deflection analyzer (HDA) and the time-of-flight (TOF) analyzer the dominating spectrometer types. Some common limiting factors for resolution and sensitivity are considered. Recent developments of the HDA and its lens system which increase the energy range and angular acceptance are described. The properties of a recently developed angle-resolving TOF system (AR-TOF) are also described. The possibility to avoid integration losses in energy or angular resolution by applying non-linear mappings of the primary data is discussed.

  14. Investigation of background processes in the KATRIN main spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Axel [Karlsruhe Institute of Technology (KIT), Institut fuer Kernphysik (IKP) (Germany); Collaboration: KATRIN-Collaboration

    2016-07-01

    The KArlsruhe TRItium Neutrino experiment aims to probe the mass of the electron antineutrino in a model-independent way with an unsurpassed sensitivity of m{sub ν}=200 meV/c{sup 2} (90% C.L.). In order to determine the neutrino mass, the energy spectrum of electrons from the tritium β-decay is analyzed by a high-resolution electrostatic spectrometer which is based on the MAC-E filter principle. To keep the influence of the spectrometer background on the neutrino mass sensitivity small, KATRIN aims for a background level of 0.01 cps. For the investigation of different background components such as cosmic muons, external gamma radiation and the radioactive decay of isotopes in the volume of the spectrometer or on its surface, a series of dedicated measurements were performed with a combined system of main spectrometer and detector. This talk presents the results of measurements focusing on the secondary electron production at the inner surface of the spectrometer and compare them with electro-magnetic electron tracking simulations performed with the KATRIN developed simulation software KASSIOPEIA.

  15. Source of monoenergetic electrons for beta dosimetry

    International Nuclear Information System (INIS)

    Graham, C.L.; Elliott, J.H.

    1983-01-01

    We have developed an electron spectrometer which can produce a continuous beam of monoenergetic electrons. The spectrometer uses 20 millicuries of Cs-137 as a source of electrons which can be magnetically focused at the exit port. Various electron energies can be selected by changing the magnetic field. The maximum electron energy and dose rate for the present design are approximately 630 keV and 1.5 rads per hour, respectively

  16. Development and performance of a suprathermal electron spectrometer to study auroral precipitations

    Energy Technology Data Exchange (ETDEWEB)

    Ogasawara, Keiichi, E-mail: kogasawara@swri.edu; Stange, Jason L.; Trevino, John A.; Webster, James [Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238 (United States); Grubbs, Guy [University of Texas at San Antonio, One UTSA circle, San Antonio, Texas 78249 (United States); Goddard Space Flight Center, National Aeronautics and Space Administration, 8800 Greenbelt Rd, Greenbelt, Maryland 20771 (United States); Michell, Robert G.; Samara, Marilia [Goddard Space Flight Center, National Aeronautics and Space Administration, 8800 Greenbelt Rd, Greenbelt, Maryland 20771 (United States); Jahn, Jörg-Micha [Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238 (United States); University of Texas at San Antonio, One UTSA circle, San Antonio, Texas 78249 (United States)

    2016-05-15

    The design, development, and performance of Medium-energy Electron SPectrometer (MESP), dedicated to the in situ observation of suprathermal electrons in the auroral ionosphere, are summarized in this paper. MESP employs a permanent magnet filter with a light tight structure to select electrons with proper energies guided to the detectors. A combination of two avalanche photodiodes and a large area solid-state detector (SSD) provided 46 total energy bins (1 keV resolution for 3−20 keV range for APDs, and 7 keV resolution for >20 keV range for SSDs). Multi-channel ultra-low power application-specific integrated circuits are also verified for the flight operation to read-out and analyze the detector signals. MESP was launched from Poker Flat Research Range on 3 March 2014 as a part of ground-to-rocket electrodynamics-electrons correlative experiment (GREECE) mission. MESP successfully measured the precipitating electrons from 3 to 120 keV in 120-ms time resolution and characterized the features of suprathermal distributions associated with auroral arcs throughout the flight. The measured electrons were showing the inverted-V type spectra, consistent with the past measurements. In addition, investigations of the suprathermal electron population indicated the existence of the energetic non-thermal distribution corresponding to the brightest aurora.

  17. Development and performance of a suprathermal electron spectrometer to study auroral precipitations

    International Nuclear Information System (INIS)

    Ogasawara, Keiichi; Stange, Jason L.; Trevino, John A.; Webster, James; Grubbs, Guy; Michell, Robert G.; Samara, Marilia; Jahn, Jörg-Micha

    2016-01-01

    The design, development, and performance of Medium-energy Electron SPectrometer (MESP), dedicated to the in situ observation of suprathermal electrons in the auroral ionosphere, are summarized in this paper. MESP employs a permanent magnet filter with a light tight structure to select electrons with proper energies guided to the detectors. A combination of two avalanche photodiodes and a large area solid-state detector (SSD) provided 46 total energy bins (1 keV resolution for 3−20 keV range for APDs, and 7 keV resolution for >20 keV range for SSDs). Multi-channel ultra-low power application-specific integrated circuits are also verified for the flight operation to read-out and analyze the detector signals. MESP was launched from Poker Flat Research Range on 3 March 2014 as a part of ground-to-rocket electrodynamics-electrons correlative experiment (GREECE) mission. MESP successfully measured the precipitating electrons from 3 to 120 keV in 120-ms time resolution and characterized the features of suprathermal distributions associated with auroral arcs throughout the flight. The measured electrons were showing the inverted-V type spectra, consistent with the past measurements. In addition, investigations of the suprathermal electron population indicated the existence of the energetic non-thermal distribution corresponding to the brightest aurora.

  18. Development of an ion time-of-flight spectrometer for neutron depth profiling

    Science.gov (United States)

    Cetiner, Mustafa Sacit

    signal. Without loss of generality, the secondary signal is obtained by the passage of the ion through a thin carbon foil, which produces ion-induced secondary electron emission (IISEE). The time-of-flight spectrometer physically acts as an ion/electron separator. The electrons that enter the active volume of the spectrometer are transported onto the microchannel plate detector to generate the secondary signal. The electron optics can be designed in variety of ways depending on the nature of the measurement and physical requirements. Two ion time-of-flight spectrometer designs are introduced: the parallel electric and magnetic (PEM) field spectrometer and the cross electric and magnetic (CEM) field spectrometer. The CEM field spectrometers have been extensively used in a wide range of applications where precise mass differentiation is required. The PEM field spectrometers have lately found interest in mass spectroscopy applications. The application of the PEM field spectrometer for energy measurements is a novel approach. The PEM field spectrometer used in the measurements employs axial electric and magnetic fields along the nominal direction of the incident ion. The secondary electrons are created by a thin carbon foil on the entrance disk and transported on the microchannel plate that faces the carbon foil. The initial angular distribution of the secondary electrons has virtually no effect on the transport time of the secondary electrons from the surface of the carbon foil to the electron microchannel plate detector. Therefore, the PEM field spectrometer can offer high-resolution energy measurement for relatively lower electric fields. The measurements with the PEM field spectrometer were made with the Tandem linear particle accelerator at the IBM T. J. Watson Research Center at Yorktown Heights, NY. The CEM field spectrometer developed for the thesis employs axial electric field along the nominal direction of the ion, and has perpendicular magnetic field. As the

  19. Creation of the precision magnetic spectrometer SCAN-3

    Directory of Open Access Journals (Sweden)

    Afanasiev S.V.

    2017-01-01

    Full Text Available The new JINR project [1] is aimed at studies of highly excited nuclear matter created in nuclei by a high-energy deuteron beam. The matter is studied through observation of its particular decay products - pairs of energetic particles with a wide opening angle, close to 180°. The new precision hybrid magnetic spectrometer SCAN-3 is to be built for detecting charged (π±, K±, p and neutral (n particles produced at the JINR Nuclotron internal target in dA collisions. One of the main and complex tasks is a study of low-energy ηA interaction and a search for η-bound states (η-mesic nuclei. Basic elements of the spectrometer and its characteristics are discussed in the article.

  20. Creation of the precision magnetic spectrometer SCAN-3

    Science.gov (United States)

    Afanasiev, S. V.; Anisimov, Yu. S.; Baldin, A. A.; Berlev, A. I.; Dryablov, D. K.; Dubinchik, B. V.; Elishev, A. F.; Fateev, O. V.; Igamkulov, Z. A.; Krechetov, Yu. F.; Kudashkin, I. V.; Kuznechov, S. N.; Malakhov, A. I.; Smirnov, V. A.; Shimansky, S. S.; Kliman, J.; Matousek, V.; Gmutsa, S.; Turzo, I.; Cruceru, I.; Cruceru, M.; Constantin, F.; Niolescu, G.; Ciolacu, L.; Paraipan, M.; Vokál, S.; Vrláková, J.; Baskov, V. A.; Lebedev, A. I.; L'vov, A. I.; Pavlyuchenko, L. N.; Polyansky, V. V.; Rzhanov, E. V.; Sidorin, S. S.; Sokol, G. A.; Glavanakov, I. V.; Tabachenko, A. N.; Jomurodov, D. M.; Bekmirzaev, R. N.; Ibadov, R. M.; Sultanov, M. U.

    2017-03-01

    The new JINR project [1] is aimed at studies of highly excited nuclear matter created in nuclei by a high-energy deuteron beam. The matter is studied through observation of its particular decay products - pairs of energetic particles with a wide opening angle, close to 180°. The new precision hybrid magnetic spectrometer SCAN-3 is to be built for detecting charged (π±, K±, p) and neutral (n) particles produced at the JINR Nuclotron internal target in dA collisions. One of the main and complex tasks is a study of low-energy ηA interaction and a search for η-bound states (η-mesic nuclei). Basic elements of the spectrometer and its characteristics are discussed in the article.

  1. The MEDUSA electron and ion spectrometer and the PIA ultraviolet photometers on Astrid-2

    Directory of Open Access Journals (Sweden)

    O. Norberg

    2001-06-01

    Full Text Available The miniature electron and ion spectrometer MEDUSA on Astrid-2 consists of two "top-hat"-type spherical electrostatic analyzers, sharing a common top-hat. Fast energy sweeps (16 electron sweeps and 8 ion sweeps per second allow for very high temporal resolution measurements of a two-dimensional slice of the particle distribution function. The energy range covered, is in the case of electrons, 4 eV to 22 keV and, in the case of ions, 2 eV to 12 keV. MEDUSA is mounted with its aperture close to the spin plane of Astrid-2, which allows for good pitch-angle coverage when the local magnetic field is in the satellite spin plane. The PIA-1/2 spin-scanning ultraviolet photometers measure auroral emissions. Using the spacecraft spin and orbital motion, it is possible to create two-dimensional images from the data. Spin-scanning photometers, such as PIA, are low-cost, low mass alternatives to auroral imagers, but place constraints on the satellite attitude. Data from MEDUSA are used to study processes in the auroral region, in particular, electrodynamics of aurora and "black aurora". MEDUSA is also a technological development, paving the way for highly capable, miniaturized particle spectrometers.Key words. Ionosphere (instruments and techniques – Magnetospheric physics (auroral phenomena; instruments and techniques

  2. The SAGE spectrometer: A tool for combined in-beam γ-ray and conversion electron spectroscopy

    International Nuclear Information System (INIS)

    Papadakis, P; Herzberg, R-D; Pakarinen, J; Butler, P A; Cox, D; Cresswell, J R; Parr, E; Sampson, J; Greenlees, P T; Sorri, J; Hauschild, K; Jones, P; Julin, R; Peura, P; Rahkila, P; Sandzelius, M; Coleman-Smith, P J; Lazarus, I H; Letts, S C; Pucknell, V F E

    2011-01-01

    The SAGE spectrometer allows simultaneous in-beam γ-ray and internal conversion electron measurements, by combining a germanium detector array with a highly segmented silicon detector and an electron transport system. SAGE is coupled with the ritu gas-filled recoil separator and the great focal-plane spectrometer for recoil-decay tagging studies. Digital electronics are used both for the γ ray and the electron parts of the spectrometer. SAGE was commissioned in the Accelerator Laboratory of the University of Jyvaeskylae in the beginning of 2010.

  3. Efficient mass calibration of magnetic sector mass spectrometers

    International Nuclear Information System (INIS)

    Roddick, J.C.

    1996-01-01

    Magnetic sector mass spectrometers used for automatic acquisition of precise isotopic data are usually controlled with Hall probes and software that uses polynomial equations to define and calibrate the mass-field relations required for mass focusing. This procedure requires a number of reference masses and careful tuning to define and maintain an accurate mass calibration. A simplified equation is presented and applied to several different magnetically controlled mass spectrometers. The equation accounts for nonlinearity in typical Hall probe controlled mass-field relations, reduces calibration to a linear fitting procedure, and is sufficiently accurate to permit calibration over a mass range of 2 to 200 amu with only two defining masses. Procedures developed can quickly correct for normal drift in calibrations and compensate for drift during isotopic analysis over a limited mass range such as a single element. The equation is: Field A·Mass 1/2 + B·(Mass) p where A, B, and p are constants. The power value p has a characteristic value for a Hall probe/controller and is insensitive to changing conditions, thus reducing calibration to a linear regression to determine optimum A and B. (author). 1 ref., 1 tab., 6 figs

  4. Development of wave length-dispersive soft x-ray emission spectrometers for transmission electron microscopes - an introduction of valence electron spectroscopy for transmission electron microscopy

    International Nuclear Information System (INIS)

    Terauchi, Masami; Koike, Masato; Fukushima, Kurio; Kimura, Atsushi

    2010-01-01

    Two types of wavelength-dispersive soft X-ray spectrometers, a high-dispersion type and a conventional one, for transmission electron microscopes were constructed. Those spectrometers were used to study the electronic states of valence electrons (bonding electrons). Both spectrometers extended the acceptable energy regions to higher than 2000 eV. The best energy resolution of 0.08 eV was obtained for an Al L-emission spectrum by using the high-dispersion type spectrometer. By using the spectrometer, C K-emission of carbon allotropes, Cu L-emission of Cu 1-x Zn x alloys and Pt M-emission spectra were presented. The FWHM value of 12 eV was obtained for the Pt Mα-emission peak. The performance of the conventional one was also presented for ZnS and a section specimen of a multilayer device. W-M and Si-K emissions were clearly resolved. Soft X-ray emission spectroscopy based on transmission electron microscopy (TEM) has an advantage for obtaining spectra from a single crystalline specimen with a defined crystal setting. As an example of anisotropic soft X-ray emission, C K-emission spectra of single crystalline graphite with different crystal settings were presented. From the spectra, density of states of π- and σ-bondings were separately derived. These results demonstrated a method to analyse the electronic states of valence electrons of materials in the nanometre scale based on TEM. (author)

  5. A superheterodyne spectrometer for electronic paramagnetic. Resonance

    International Nuclear Information System (INIS)

    Laffon, J.L.

    1963-12-01

    After a few generalities about electron paramagnetic resonance, a consideration of different experimental techniques authorises the choice of a particular type of apparatus. An EPR superheterodyne spectrometer built in the laboratory and having a novel circuit is described in detail. With this apparatus, many experimental results have been obtained and some of these are described as example. (author) [fr

  6. Polarized neutron spectrometer

    International Nuclear Information System (INIS)

    Abov, Yu.G.; Novitskij, V.V.; Alfimenkov, V.P.; Galinskij, E.M.; Mareev, Yu.D.; Pikel'ner, L.B.; Chernikov, A.N.; Lason', L.; Tsulaya, V.M.; Tsulaya, M.I.

    2000-01-01

    The polarized neutron spectrometer, intended for studying the interaction of polarized neutrons with nuclei and condensed media in the area of energies from thermal up to several electron-volt, is developed at the IBR-2 reactor (JINR, Dubna). Diffraction on the Co(92%)-Fe(8%) magnetized monocrystals is used for the neutron polarization and polarization analysis. The neutron polarization within the whole energy range equals ∼ 95% [ru

  7. Mini ion trap mass spectrometer

    Science.gov (United States)

    Dietrich, D.D.; Keville, R.F.

    1995-09-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  8. Very large solid angle spectrometer for single arm electron scattering experiments

    International Nuclear Information System (INIS)

    Leconte, P.

    1981-01-01

    Major information about short range behavior of nuclear forces should be obtained through electron scattering experiments at high momentum transfer. Cross sections will be very low as is usually the case in electron scattering. In order to reach them, the solid angle of the detection system will have to be enlarged. Traditional optics cannot give correct answer to the problem. For very large apertures, it is impossible to obtain good focussing properties which provide accurate momentum/position correlation with no dependence on the entrance angles. Furthermore, the experiment will require the measurement of these angles. It means that the final system will be equipped with a complete set of position sensitive detectors able to measure positions and angles of trajectories in both planes. Then, the question arises: is it really necessary to provide good focussing, or more precisely: is it possible to get all the required information without the help of a sophisticated predetermined magnetic optics. We try to answer this question and then to sketch from a new point of view the best spectrometer we could think of

  9. Automation of electrostatic and magnetic beta-spectrometers; Avtomatizatsiya ehlektrostaticheskogo i magnitnogo {beta}-spektrometra

    Energy Technology Data Exchange (ETDEWEB)

    Sidorov, V T; Petev, P A

    1996-12-31

    Paper describes control units of voltage and current NM respectively, for electrostatic and magnetic beta-spectrometers. These units may be designed on the basis of either SPELMAN company voltage devider ensuring 0.5 accuracy or using a computer modification of feedback. Software for automated electrostatic beta-spectrometer made according to CAMAC standards is considered. 5 figs.

  10. Tracking performances of the dimuon spectrometer with a dipole magnet

    International Nuclear Information System (INIS)

    Cussonneau, J.P.; Gutbrod, H.; Lautridou, P.; Luquin, L.; Metivier, V.; Ramillien, V.

    1996-01-01

    The tracking performances of the ALICE forward muon spectrometer, with a dipole magnet, are investigated. The study concerns the track finding and the mass resolution as well as the acceptance of the spectrometer for the Φ's, J/Ψ's and Υ's. With the proposed setup, a mass resolution below 100 MeV is obtained and a track finding efficiency better than 90% is achieved for the heavy resonance. An absolute acceptance of 4.83% is found which is acceptable in order to reach the required statistic for Υ' and Υ'' in Pb-Pb collisions. (author)

  11. Efficient mass calibration of magnetic sector mass spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Roddick, J C

    1997-12-31

    Magnetic sector mass spectrometers used for automatic acquisition of precise isotopic data are usually controlled with Hall probes and software that uses polynomial equations to define and calibrate the mass-field relations required for mass focusing. This procedure requires a number of reference masses and careful tuning to define and maintain an accurate mass calibration. A simplified equation is presented and applied to several different magnetically controlled mass spectrometers. The equation accounts for nonlinearity in typical Hall probe controlled mass-field relations, reduces calibration to a linear fitting procedure, and is sufficiently accurate to permit calibration over a mass range of 2 to 200 amu with only two defining masses. Procedures developed can quickly correct for normal drift in calibrations and compensate for drift during isotopic analysis over a limited mass range such as a single element. The equation is: Field A{center_dot}Mass{sup 1/2} + B{center_dot}(Mass){sup p} where A, B, and p are constants. The power value p has a characteristic value for a Hall probe/controller and is insensitive to changing conditions, thus reducing calibration to a linear regression to determine optimum A and B. (author). 1 ref., 1 tab., 6 figs.

  12. Computing strategy of Alpha-Magnetic Spectrometer experiment

    International Nuclear Information System (INIS)

    Choutko, V.; Klimentov, A.

    2003-01-01

    Alpha-Magnetic Spectrometer (AMS) is an experiment to search in the space for dark matter, missing matter, and antimatter scheduled for being flown on the International Space Station in the fall of year 2005 for at least 3 consecutive years. This paper gives an overview of the AMS software with emphasis on the distributed production system based on client/server approach. We also describe our choice of hardware components to build a processing farm with TByte RAID arrays of IDE disks and highlight the strategies that make our system different from many other experimental systems

  13. Project for a high resolution magnetic spectrometer for heavy ions

    International Nuclear Information System (INIS)

    Birien, P.; Valero, S.

    1981-05-01

    The energy loss spectrometer presented in this report has an energy resolution of 2x10 -4 with the full solid angle of 5 msr. The maximum magnetic rigidity of the particles analysed is 2.88 Tesla-meters on the optical axis and the total acceptance in energy is 14%. Experiments with reaction angles near 0 0 are possible. Kinematic compensation is adapted to heavy ion physics. In this report, we have paid special attention to the simplicity of the construction and of the use of this spectrometer by experimentalists. This report is addressed both to non-specialists and to future users as well [fr

  14. Method for internal conversion coefficients determination by means of a magnetic spectrometer. Application to 129Xe and 77Se

    International Nuclear Information System (INIS)

    Arqueros, F.; Campos, J.

    1986-01-01

    The method used for efficiency calibration of a magnetic electron spectrometer and its applications to conversion electron spectrometry is described. The present results point out that apparatus combining magnetic deflection and semiconductor detection have a nondecreasing interest in nuclear spectrometry for applications where good resolution and large background rejection are both necessary. The present apparatus can be employed with source of relatively low activity, (0.lμCi). The nuclides studied were 129 Xe and 77 Se resulting from 129 Cs and 77 Br decay. The parent nulcides were produced in ISOLDE on line isotope separator at CERN. The efficiency calibration method used for energies higher than 200 keV made use of the well known beta spectrum of 36 Cl. The calibration for low energies was made with Auger electron intensities and suitable conversion lines of 129 Xenon. Results for relative intensities of conversion electron lines and intense gamma lines of 129 Xe and 77 Se are given. From these measurements internal conversion coefficients for transitions of both nuclides were obtained. The results were in agreement with theoretical calculations. (author)

  15. A solenoidal electron spectrometer for a precision measurement of the neutron β-asymmetry with ultracold neutrons

    International Nuclear Information System (INIS)

    Plaster, B.; Carr, R.; Filippone, B.W.; Harrison, D.; Hsiao, J.; Ito, T.M.; Liu, J.; Martin, J.W.; Tipton, B.; Yuan, J.

    2008-01-01

    We describe an electron spectrometer designed for a precision measurement of the neutron β-asymmetry with spin-polarized ultracold neutrons. The spectrometer consists of a 1.0-T solenoidal field with two identical multiwire proportional chamber and plastic scintillator electron detector packages situated within 0.6-T field-expansion regions. Select results from performance studies of the spectrometer with calibration sources are reported

  16. A solenoidal electron spectrometer for a precision measurement of the neutron {beta}-asymmetry with ultracold neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Plaster, B. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States)], E-mail: plaster@pa.uky.edu; Carr, R.; Filippone, B.W. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Harrison, D. [Physics Department, University of Winnipeg, Manitoba, Canada R3B 2E9 (Canada); Hsiao, J. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Ito, T.M. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Liu, J. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Martin, J.W. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Physics Department, University of Winnipeg, Manitoba, R3B 2E9 (Canada); Tipton, B.; Yuan, J. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

    2008-10-11

    We describe an electron spectrometer designed for a precision measurement of the neutron {beta}-asymmetry with spin-polarized ultracold neutrons. The spectrometer consists of a 1.0-T solenoidal field with two identical multiwire proportional chamber and plastic scintillator electron detector packages situated within 0.6-T field-expansion regions. Select results from performance studies of the spectrometer with calibration sources are reported.

  17. The Nab Spectrometer, Precision Field Mapping, and Associated Systematic Effects

    Science.gov (United States)

    Fry, Jason; Nab Collaboration

    2017-09-01

    The Nab experiment will make precision measurements of a, the e- ν correlation parameter, and b, the Fierz interference term, in neutron beta decay, aiming to deliver an independent determination of the ratio λ =GA /GV to sensitively test CKM unitarity. Nab utilizes a novel, long asymmetric spectrometer to measure the proton TOF and electron energy. We extract a from the slope of the measured TOF distribution for different electron energies. A reliable relation of the measured proton TOF to a requires detailed knowledge of the effective proton pathlength, which in turn imposes further requirements on the precision of the magnetic fields in the Nab spectrometer. The Nab spectrometer, magnetometry, and associated systematics will be discussed.

  18. Performance of drift chambers in a magnetic rigidity spectrometer for measuring the cosmic radiation

    International Nuclear Information System (INIS)

    Hof, M.; Bremerich, M.; Menn, W.; Pfeifer, C.; Reimer, O.; Simon, M.; Mitchell, J.W.; Barbier, L.M.; Christian, E.R.; Ormes, J.F.; Streitmatter, R.E.; Golden, R.L.; Stochaj, S.J.

    1994-01-01

    A drift chamber tracking system was developed and flown as part of the IMAX balloon-borne magnetic spectrometer. The drift chamber uses a hexagonal drift-cell structure and is filled with pure CO 2 gas. It operated with high efficiency in the strong and inhomogenous field of a superconducting magnet, demonstrating a spatial resolution of better than 100 μm over most of the drift path for singly charged particles, as well as for helium and lithium nuclei. The drift chamber portion of the spectrometer achieved a maximum detectable rigidity of 175 and 250 GV/c for protons and helium respectively. ((orig.))

  19. Description of the double Compton spectrometer at Mayence MPI

    International Nuclear Information System (INIS)

    Borchert, H.; Ziegler, B.; Gimm, H.; Zieger, A.; Hughes, R.J.; Ahrens, J.

    1977-01-01

    The double Compton spectrometer of the Laboratories of the Mayence Linear Accelerator consists in two identical magnetic spectrometers, in which the electron scattered forwards by photons through a Compton process, are detected. The spectrometers have been built to detect 10-350 MeV photons and, as they involve thin Compton targets, their effect on the photon flux is negligible. They are put in cascade inside a well collimated bremsstrahlung beam. A thick absorbing target (max. thickness 2m) can be inserted inside the beam. The facility is outlined, some special properties of the accelerator and the bremsstrahlung beam are given. The properties of a Compton spectrometer involving eleven detectors are given by eleven response functions giving the relations between the photon flux impinging the Compton target and the counting rates of the detectors for a given adjustment of the magnets. A Monte-Carlo method is used for the calculation together with analytical methods neglecting the multiple scattering effects [fr

  20. The magnetic spectrometer of the PAMELA satellite experiment

    International Nuclear Information System (INIS)

    Adriani, O.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Gabbanini, A.; Grandi, M.; Papini, P.; Ricciarini, S.B.; Spillantini, P.; Straulino, S.; Taccetti, F.; Tesi, M.; Vannuccini, E.

    2003-01-01

    In this paper, we describe in detail the design and the construction of the magnetic spectrometer of the PAMELA experiment, that will be launched during 2003 to do a precise measurement of the energy spectra of the antimatter components in cosmic rays. This paper will mainly focus on the detailed description of the tracking system and on the solutions adopted to deal with the technical challenges that are required to build a very precise detector to be used in the hostile space environment

  1. Double differential distributions of electron emission in ion-atom and electron-atom collisions using an electron spectrometer

    International Nuclear Information System (INIS)

    Misra, Deepankar; Thulasiram, K.V.; Fernandes, W.; Kelkar, Aditya H.; Kadhane, U.; Kumar, Ajay; Singh, Yeshpal; Gulyas, L.; Tribedi, Lokesh C.

    2009-01-01

    We study electron emission from atoms and molecules in collisions with fast electrons and heavy ions (C 6+ ). The soft collision electrons (SE), two center electron emission (TCEE), the binary encounter (BE) events and the KLL Auger lines along with the elastically scattered peaks (in electron collisions) are studied using a hemispherical electrostatic electron analyzer. The details of the measurements along with description of the spectrometer and data acquisition system are given. The angular distributions of the low energy (few eV) electrons in soft collisions and the binary encounter electrons at keV energies are compared with quantum mechanical models based on the first Born (B1) and the continuum distorted wave-Eikonal initial state approximation (CDW-EIS).

  2. Development of an electron momentum spectrometer for time-resolved experiments employing nanosecond pulsed electron beam

    Science.gov (United States)

    Tang, Yaguo; Shan, Xu; Liu, Zhaohui; Niu, Shanshan; Wang, Enliang; Chen, Xiangjun

    2018-03-01

    The low count rate of (e, 2e) electron momentum spectroscopy (EMS) has long been a major limitation of its application to the investigation of molecular dynamics. Here we report a new EMS apparatus developed for time-resolved experiments in the nanosecond time scale, in which a double toroidal energy analyzer is utilized to improve the sensitivity of the spectrometer and a nanosecond pulsed electron gun with a repetition rate of 10 kHz is used to obtain an average beam current up to nA. Meanwhile, a picosecond ultraviolet laser with a repetition rate of 5 kHz is introduced to pump the sample target. The time zero is determined by photoionizing the target using a pump laser and monitoring the change of the electron beam current with time delay between the laser pulse and electron pulse, which is influenced by the plasma induced by the photoionization. The performance of the spectrometer is demonstrated by the EMS measurement on argon using a pulsed electron beam, illustrating the potential abilities of the apparatus for investigating the molecular dynamics in excited states when employing the pump-probe scheme.

  3. An approximately 4π tracking magnetic spectrometer for RHIC

    International Nuclear Information System (INIS)

    1987-01-01

    A tracking magnetic spectrometer based on large Time Projection Chambers (TPC) is proposed to measure the momentum of charged particles emerging from the RHIC beam pipe at angles larger than four degrees and to identify the particle type for those beyond fifteen degrees with momenta up to 700 MeV/c, which is a large fraction of the final charged particles emitted by a low rapidity quark-gluon plasma

  4. Electron spectroscopy for surface analysis - the ES300 electron spectrometer and its applications

    International Nuclear Information System (INIS)

    Walker, J.A.J.; Price, W.B.

    1980-07-01

    The features of the ES300 electron spectrometer are described together with factors which affect the energy spectrum, experimental variables and interpretation of the spectral information. A discussion of five applications illustrates the use of X-ray photo-electron spectroscopy (XPS) in the diverse work of the Risley Nuclear Power Development Laboratories (RNL). The analytical results are given for each of the examples and their interpretation discussed in the chemical context of the original problem. (author)

  5. Laser generated hot electron transport in an externally applied magnetic field

    International Nuclear Information System (INIS)

    Burnett, N.H.; Enright, G.D.

    1986-01-01

    The authors have investigated the effect of an externally applied DC magnetic field on the generation and transport of hot electrons in CO/sub 2/ laser irradiation of cylindrical targets. The targets used in these studies were 6.3 mm diameter metal rods through which a pulsed current was driven from an external capacitor. Magnetic fields up to 150 kgauss were produced at the target surface. The CO/sub 2/ laser was focused with an f/5 lens resulting in a laser intensity of ≅3 x 10/sup 14/ W/cm/sup 2/ in a 100 μm diameter focal spot. The effect of the external magnetic field on the generation and inward transport of superhot (≥ 100 keV) electrons was studied. Principal diagnostics included a six channel hard x-ray spectrometer, a high energy x-ray pinhole camera, a LiF Laue x-ray spectrograph and a Ross-filtered (W-Ta) pair of x-ray detectors. The latter two diagnostics were designed to detect Au Kα /sub emission at 68.2 keV

  6. Nuclear Magnetic Resonance Spectrometer Console Upgrade for a Type II Quantum Computer

    National Research Council Canada - National Science Library

    Cory, David

    2003-01-01

    ...) spectrometer to enable an improved implementation of type II quantum computers (TTQC). This upgrade is fully functional and has permitted our NMR studies to be moved to higher strength magnetic fields for better sensitivity and spectral dispersion...

  7. A permanent magnet system for a cyclotron used as a mass spectrometer

    International Nuclear Information System (INIS)

    Li, C.Y.; Cooper, M.; Halbach, K.; Kunkel, W.B.; Leung, K.N.; Wells, R.P.; Young, A.T.

    1992-07-01

    The design of a compact, low energy cyclotron used as a mass spectrometer is presented. The instrument is designed for high resolution, high sensitivity detection of trace. It features the use of permanent magnets to excite the soft iron pole pieces which provide the magnetic field of the cyclotron. Tuning magnets are used to enable the field to be varied. This significantly improves the operational requirements of the instrument when compared to one which uses electromagnets. The cyclotron will use a spiral reflector for axial injection

  8. Constant-gap spectrometer design for the electron/ion collider ELISe

    International Nuclear Information System (INIS)

    Adachi, T.; Harakeh, M.N.; Kalantar-Nayestanaki, N.; Wörtche, H.J.; Berg, G.P.A.; Simon, H.; Koop, I.A.; Couder, M.; Fujiwara, M.

    2011-01-01

    For the study of electron-scattering off radioactive nuclei, the ELISe spectrometer will be constructed as a part of the Facility of Antiprotons and Ion Research (FAIR) in Darmstadt. A conceptional design of a spectrometer with a “clam-shell” gap was presented before. Here, we will present an improved design with a pre-deflector with a constant gap. Such a pre-deflector is not only simpler to construct but also provides larger angle acceptances in the forward-angle range compared to those with the “clam-shell” design.

  9. Setup of Mössbauer spectrometers at RCPTM

    Science.gov (United States)

    Pechoušek, J.; Jančík, D.; Frydrych, J.; Navařík, J.; Novák, P.

    2012-10-01

    Setup of Mössbauer spectrometers (MS) for structural, phase, and magnetic characterization of iron-or tin-containing samples is presented. This comprehensive line of 57Fe and 119Sn Mössbauer spectrometers covers transmission spectrometers (TMS) for roomtemperature (RT) measurements, temperature dependent measurements and measurements in an external magnetic field. An RT Conversion Electron/Conversion X-ray Mössbauer technique (CEMS/CXMS) is also available. The main concept of the RT MS is a table-top spectrometric bench with a control unit based on special-purpose hardware or standard PC platform. The first way offers a compact design and PC independent spectra collection system. The second setup, a PC-based system, which uses commercial devices and LabVIEW software, offers easy customization and enables advancement in spectrometer construction. The both types of control systems are able to operate special parts (velocity transducers, gamma-ray detectors) of unusual spectrometric benches. The standard velocity axis range is up to ±20 mm/s with a maximum nonlinearity of 0.1%. Applicable measuring conditions of presented TMSs cover a cryogenic temperature range from 1.5 up to 300 K and high temperature range from RT up to 1000 °C. With in-field low-temperature MS, we are able to analyze samples normally in the external magnetic fields up to 8 T (in temperature interval from 1.5 up to 300 K). In addition, special modes of measurements can be applied including backscattering gamma-ray geometry or measurement in an inert or controlled-humidity atmosphere. Technical details and construction aspects of spectrometers are presented.

  10. Removal of stored particle background via the electric dipole method in the KATRIN main spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Hilk, Daniel [Institut fuer Experimentelle Kernphysik, KIT, Karlsruhe (Germany); Collaboration: KATRIN-Collaboration

    2016-07-01

    The goal of the KArlsruhe TRItium Neutrino (KATRIN) experiment is to determine the effective mass of the electron anti neutrino by measuring the electron energy spectrum of tritium beta decay near the endpoint. The goal is to reach a sensitivity on the neutrino mass of 200 meV for which a low background level of 10{sup -2} counts per second is mandatory. Electrons from single radioactive decays of radon and tritium in the KATRIN main spectrometer with energies in the keV range can be magnetically stored for hours. While cooling down via ionization of residual gas molecules, they produce hundreds of secondary electrons, which can reach the detector and contribute to the background signals. In order to suppress this background component, several methods are investigated to remove stored electrons, such as the application of an electric dipole field and the application of magnetic pulses. This talk introduces the mechanism of background production due to stored electrons and their removal by the electric dipole method in the main spectrometer. In context of the spectrometer- and detector-commissioning phase in summer 2015, measurement results of the application of the electric dipole method are presented.

  11. A double zero-dispersion magnetic spectrometer used in a telescopic mode for very forward heavy ions studies

    International Nuclear Information System (INIS)

    Bacri, C.O.; Roussel, P.

    1990-01-01

    An original method based on the use of a double magnetic spectrometer in a telescopic mode is proposed for the studies of heavy ions collisions both at very forward angles and for magnetic rigidities close to that of the beam. It consists in the direct measurement of angular distributions on doubly - Bρ and angle - sorted events. The method has been tested on the LISE spectrometer at GANIL with a 44 MeV/A 40 Ar beam impinging on C, Al, Ni and Au targets. Milliradian angular accuracy have been obtained at magnetic rigidities as close as 0.9977 of that of the beam

  12. Small angle spectrometers: Summary

    International Nuclear Information System (INIS)

    Courant, E.; Foley, K.J.; Schlein, P.E.

    1986-01-01

    Aspects of experiments at small angles at the Superconducting Super Collider are considered. Topics summarized include a small angle spectrometer, a high contingency spectrometer, dipole and toroid spectrometers, and magnet choices

  13. Los Alamos Meson Physics Facility high-resolution-spectrometer dipole magnets: a summary report

    International Nuclear Information System (INIS)

    Kozlowski, T.; Madland, D.G.; Rolfe, R.; Smith, W.E.; Spencer, J.E.; Tanaka, N.; Thiessen, H.A.; Varghese, P.; Wilkerson, L.C.

    1982-12-01

    This report explains the design, fabrication, measurement, optimization, and installation of two 122 metric ton electromagnets for the High Resolution Proton Spectrometer at the Los Alamos Meson Physics Facility. These two magnets are the principal components of the proton spectrometer, which has an energy resolution of less than or equal to 10 - 4 FWHM. Many technical problems occurred during fabrication, measurement, and optimization, and the majority have been successfully solved. We hope that this report will help others planning similar projects

  14. Results on search for a QGP with a TPC magnetic spectrometer at AGS and plans for an ∼4π TPC magnetic spectrometer at RHIC

    International Nuclear Information System (INIS)

    Lindenbaum, S.J.

    1991-01-01

    In the first part of this paper a search for a Quark-Gluon Plasma (QGP) with a TPC Magnetic Spectrometer at AGS by the BNL/CCNY/Johns Hopkins/Rice (E-810) Collaboration is discussed. At AGS energies the expected increase in baryon density is near maximum. If a QGP is formed even rarely this approach provides a sensitive method for its detection. We have found some interesting phenomena including strangeness enhancement, multi-Λ and K s 0 events and an increased slope for π - (corresponding to a reduced temperature) in the usual temperature plot for p perpendicular < 0.2 GeV/c. We plan to increase the statistics with the 14.5 GeV/c x A Si ions on targets from light to heavy and then to continue the program with incident Au ions. In Part 2 we discuss the BNL/CCNY/Notre Dame/Rice proposal for an ∼ 4π TPC Magnetic Spectrometer for RHIC which we believe will be a sensitive probe for hadronic QGP signals, and also capable of observing departures from QCD should they occur. 8 refs., 12 figs

  15. Operations of the thermal control system for Alpha Magnetic Spectrometer electronics following the beta angle of the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Kun; Li, Jinbo; Cui, Zheng; Wang, Naihua; Sun, Qie; Cheng, Lin, E-mail: cheng@sdu.edu.cn

    2014-12-11

    The Alpha Magnetic Spectrometer (AMS) has been running and measuring cosmic rays on the International Space Station (ISS) since May 19, 2011. The thermal control system (TCS) plays an important role in keeping all components and equipment working in an operational temperature range. Since the AMS started working on the ISS, AMS thermal engineers have been monitoring the on-orbit status of the TCS. During normal operation, the local temperature of AMS components regularly varies along with the β angle of the ISS. Based on the collected temperature data, the general characteristics of local temperature variations of TCS for AMS Electronics following the β of the ISS are discussed with the statistics of the orbit-averaged temperature and the orbit standard deviation of temperature. Furthermore some temperature anomalies at specific β are also studied. - Highlights: • The variation of the main radiators temperature is statistically analyzed. • The hot case and cold case for the main radiators are found in normal operations. • The solar illumination falling on the inner sheet of RAM radiator leads to temperature jump. • The temperature anomalies on the WAKE radiator show a uniform trend except WR3 sensor. • The regularity of the temperature variation is described with fitted equations.

  16. A simple photoionization scheme for characterizing electron and ion spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Wituschek, A.; Vangerow, J. von; Grzesiak, J.; Stienkemeier, F.; Mudrich, M., E-mail: mudrich@physik.uni-freiburg.de [Physikalisches Institut, Universität Freiburg, 79104 Freiburg (Germany)

    2016-08-15

    We present a simple diode laser-based photoionization scheme for generating electrons and ions with well-defined spatial and energetic (≲2 eV) structures. This scheme can easily be implemented in ion or electron imaging spectrometers for the purpose of off-line characterization and calibration. The low laser power ∼1 mW needed from a passively stabilized diode laser and the low flux of potassium atoms in an effusive beam make our scheme a versatile source of ions and electrons for applications in research and education.

  17. Test report: Electron-proton spectrometer qualification test unit, qualification test

    Science.gov (United States)

    Vincent, D. L.

    1972-01-01

    Qualification tests of the electron-proton spectrometer test unit are presented. The tests conducted were: (1) functional, (2) thermal/vacuum, (3) electromagnetic interference, (4) acoustic, (5) shock, (6) vibration, and (7) humidity. Results of each type of test are presented in the form of data sheets.

  18. Reflection-time-of-flight spectrometer for two-electron (e,2e) coincidence spectroscopy on surfaces

    International Nuclear Information System (INIS)

    Kirschner, J.; Kerherve, G.; Winkler, C.

    2008-01-01

    In this article, a novel time-of-flight spectrometer for two-electron-emission (e,2e/γ,2e) correlation spectroscopy from surfaces at low electron energies is presented. The spectrometer consists of electron optics that collect emitted electrons over a solid angle of approximately 1 sr and focus them onto a multichannel plate using a reflection technique. The flight time of an electron with kinetic energy of E kin ≅25 eV is around 100 ns. The corresponding time- and energy resolution are typically ≅1 ns and ≅0.65 eV, respectively. The first (e,2e) data obtained with the present setup from a LiF film are presented

  19. Wide angle spectrometers for intermadiate energy electron accelerators

    International Nuclear Information System (INIS)

    Leconte, P.

    1982-10-01

    It is shown that improvements of the detector acceptances (in solid angle and momentum bite) is as important as increased duty cycle for coincidence experiments. To have a maximum efficiency and thus to reduce the cost of experiments, it is imperative to develop maximum solid angle systems. This implies an axial symmetry with respect to the incoming beam. At Saclay, we have investigated some of the properties of specific detectors covering up to 90% of 4π steradians for a high energy, 100% duty cycle electron accelerator. The techniques of wide angle spectrometers have already been explored on a large scale in high energy physics. However, in the case of charged particles, such detectors, compared to classical iron dipole spectrometers, present a smaller resolving power and a rather low background rejection. The choice of which of these two solutions is to be used depends on the conditions of the specific experiment

  20. Initial results of the mexican participation in the Alpha Magnetic Spectrometer Project

    International Nuclear Information System (INIS)

    Belmont M, E.; Menchaca R, A.; Sandoval, A.; Alfaro, R.; Martinez D, A.; Grabski, V.

    2007-01-01

    Mexico is part of the AMS (Alpha Magnetic Spectrometer) project, consisting of several radiation detectors integrated in a single telescope to be sent to the outer space in search of antimatter. One of those detectors is a RICH (Ring Imaging Cherenkov), where the cosmic particle's speed is calculated from the Cherenkov light-rings observed. The IF-UNAM group works in characterizing the silica aerogel used as luminous element in this detector. Because the spectrometer will be in orbit for several years, some particular studies are necessary. Our group works on possible ageing mechanisms, showing that the main threat to this material is contamination rather than thermal, or vacuum, shocks. (Author)

  1. Development of low background germanium spectrometer for measurement of neutrino magnetic moment

    CERN Document Server

    Beda, A G; Starostin, A S

    2000-01-01

    The prospects for a search for neutrino magnetic moment down to (3-5)centre dot 10 sup - sup 1 sup 1 of the Bohr magneton with the use of low background Ge-NaI spectrometer built in ITEP are discussed. The lowest level of background for shallow setups was achieved in the preliminary test measurements of background. This result and estimations of additional sources of the background in a reactor experiment testify that using the low background Ge-NaI spectrometer with mass of Ge-crystal of 2 kg it is possible to achieve above objective, that will be one order of magnitude better than the present experimental limit.

  2. The SAGE spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Pakarinen, J.; Papadakis, P. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Sorri, J.; Greenlees, P.T.; Jones, P.; Julin, R.; Konki, J.; Rahkila, P.; Sandzelius, M. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Herzberg, R.D.; Butler, P.A.; Cox, D.M.; Cresswell, J.R.; Mistry, A.; Page, R.D.; Parr, E.; Sampson, J.; Seddon, D.A.; Thornhill, J.; Wells, D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Coleman-Smith, P.J.; Lazarus, I.H.; Letts, S.C.; Pucknell, V.F.E.; Simpson, J. [STFC Daresbury Laboratory, Warrington (United Kingdom)

    2014-03-15

    The SAGE spectrometer has been constructed for in-beam nuclear structure studies. SAGE combines a Ge-detector array and an electron spectrometer for detection of γ-rays and internal conversion electrons, respectively, and allows simultaneous observation of both electrons and γ-rays emitted from excited nuclei. SAGE is set up in the Accelerator Laboratory of the University of Jyvaeskylae and works in conjunction with the RITU gas-filled recoil separator and the GREAT focal-plane spectrometer allowing the use of the recoil-decay tagging method. (orig.)

  3. The SAGE spectrometer

    International Nuclear Information System (INIS)

    Pakarinen, J.; Papadakis, P.; Sorri, J.; Greenlees, P.T.; Jones, P.; Julin, R.; Konki, J.; Rahkila, P.; Sandzelius, M.; Herzberg, R.D.; Butler, P.A.; Cox, D.M.; Cresswell, J.R.; Mistry, A.; Page, R.D.; Parr, E.; Sampson, J.; Seddon, D.A.; Thornhill, J.; Wells, D.; Coleman-Smith, P.J.; Lazarus, I.H.; Letts, S.C.; Pucknell, V.F.E.; Simpson, J.

    2014-01-01

    The SAGE spectrometer has been constructed for in-beam nuclear structure studies. SAGE combines a Ge-detector array and an electron spectrometer for detection of γ-rays and internal conversion electrons, respectively, and allows simultaneous observation of both electrons and γ-rays emitted from excited nuclei. SAGE is set up in the Accelerator Laboratory of the University of Jyvaeskylae and works in conjunction with the RITU gas-filled recoil separator and the GREAT focal-plane spectrometer allowing the use of the recoil-decay tagging method. (orig.)

  4. A four-detector spectrometer for e--γ PAC on-line with the ISOLDE-CERN isotope separator

    International Nuclear Information System (INIS)

    Marques, J.G.; Correia, J.G.; Melo, A.A.; Silva, M.F. da; Soares, J.C.

    1995-01-01

    A four-detector e - -γ spectrometer has been installed on-line with the ISOLDE isotope separator. The spectrometer consists of two magnetic lenses for detection of conversion electrons, and two BaF 2 scintillators for γ-ray detection. The spectrometer has been equipped with a 20 kV pre-acceleration system which enables detection of conversion electrons down to 2 keV. Implantation and measurement can be performed simultaneously on a large temperature range by heating or cooling the sample holder. The advantages of using the e - -γ PAC technique on-line at ISOLDE are discussed. (orig.)

  5. A condensed matter electron momentum spectrometer with parallel detection in energy and momentum

    Energy Technology Data Exchange (ETDEWEB)

    Storer, P; Caprari, R S; Clark, S A.C.; Vos, M; Weigold, E

    1994-03-01

    An electron momentum spectrometer has been constructed which measures electron binding energies and momenta by fully determining the kinematics of the incident, scattered and ejected electrons resulting from (e,2e) ionizing collisions in a thin solid foil. The spectrometer operates with incident beam energies of 20-30 keV in an asymmetric, non-coplanar scattering geometry. Bethe ridge kinematics are used. The technique uses transmission through the target foil, but it is most sensitive to the surface from which the 1.2 keV electrons emerge, to a depth of about 5 nm. Scattered and ejected electron energies and azimuthal angles are detected in parallel using position sensitive detection, yielding true coincidence count rates of 6 Hz from a 5.5 nm thick evaporated carbon target and an incident beam current of around 100 nA. The energy resolution is approximately 1.3 eV and momentum resolution approximately 0.15 a{sub 0}{sup -1}. The energy resolution could readily be improved by monochromating the incident electron beam. 28 refs., 15 figs.

  6. A condensed matter electron momentum spectrometer with parallel detection in energy and momentum

    International Nuclear Information System (INIS)

    Storer, P.; Caprari, R.S.; Clark, S.A.C.; Vos, M.; Weigold, E.

    1994-03-01

    An electron momentum spectrometer has been constructed which measures electron binding energies and momenta by fully determining the kinematics of the incident, scattered and ejected electrons resulting from (e,2e) ionizing collisions in a thin solid foil. The spectrometer operates with incident beam energies of 20-30 keV in an asymmetric, non-coplanar scattering geometry. Bethe ridge kinematics are used. The technique uses transmission through the target foil, but it is most sensitive to the surface from which the 1.2 keV electrons emerge, to a depth of about 5 nm. Scattered and ejected electron energies and azimuthal angles are detected in parallel using position sensitive detection, yielding true coincidence count rates of 6 Hz from a 5.5 nm thick evaporated carbon target and an incident beam current of around 100 nA. The energy resolution is approximately 1.3 eV and momentum resolution approximately 0.15 a 0 -1 . The energy resolution could readily be improved by monochromating the incident electron beam. 28 refs., 15 figs

  7. The Wavelength-Dispersive Spectrometer and Its Proposed Use in the Analytical Electron Microscope

    Science.gov (United States)

    Goldstein, Joseph I.; Lyman, Charles E.; Williams, David B.

    1989-01-01

    The Analytical Electron Microscope (AEM) equipped with a wavelength-dispersive spectrometer (WDS) should have the ability to resolve peaks which normally overlap in the spectra from an energy-dispersive spectrometer (EDS). With a WDS it should also be possible to measure lower concentrations of elements in thin foils due to the increased peak-to-background ratio compared with EDS. The WDS will measure X-ray from the light elements (4 less than Z less than 1O) more effectively. This paper addresses the possibility of interfacing a compact WDS with a focussing circle of approximately 4 cm to a modem AEM with a high-brightness (field emission) source of electrons.

  8. Angle-resolving time-of-flight electron spectrometer for near-threshold precision measurements of differential cross sections of electron-impact excitation of atoms and molecules

    International Nuclear Information System (INIS)

    Lange, M.; Matsumoto, J.; Setiawan, A.; Panajotovic, R.; Harrison, J.; Lower, J. C. A.; Newman, D. S.; Mondal, S.; Buckman, S. J.

    2008-01-01

    This article presents a new type of low-energy crossed-beam electron spectrometer for measuring angular differential cross sections of electron-impact excitation of atomic and molecular targets. Designed for investigations at energies close to excitation thresholds, the spectrometer combines a pulsed electron beam with the time-of-flight technique to distinguish between scattering channels. A large-area, position-sensitive detector is used to offset the low average scattering rate resulting from the pulsing duty cycle, without sacrificing angular resolution. A total energy resolution better than 150 meV (full width at half maximum) at scattered energies of 0.5-3 eV is achieved by monochromating the electron beam prior to pulsing it. The results of a precision measurement of the differential cross section for electron-impact excitation of helium, at an energy of 22 eV, are used to assess the sensitivity and resolution of the spectrometer

  9. One of the three multiwire proportional chambers used in the photon tagging system at the Omega spectrometer

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The momentum of incoming electrons, generated by SPS beams, is determined by magnets before they are directed onto a foil. The tagging system, a magnet and the MWPCs then determines the electron momentum after the foil and the difference between the two measurements gives the momentum of the photon which is heading for the spectrometer. The MWPCs were built in Daresburyand coupled with new CERN read0ut electronics.

  10. Design and realization of a space-borne reflectron time of flight mass spectrometer: electronics and measuring head

    International Nuclear Information System (INIS)

    Devoto, P.

    2006-03-01

    The purpose of this thesis is the design of the electronics of a time of flight mass spectrometer, the making and the vacuum tests of a prototype which can be put onboard a satellite. A particular effort was necessary to decrease to the maximum the mass and electric consumption of the spectrometer, which led to the development of new circuits. The work completed during this thesis initially concerns the electronics of the measuring equipment which was conceived in a concern for modularity. A complete 'reflectron' type mass spectrometer was then designed, simulated and developed. The built prototype, which uses the developed electronics, was exposed to ion flows of different masses and energies in the CESR vacuum chambers. Its measured performances validate the implemented principles and show that an identical mass spectrometer can be put onboard a satellite with profit, for planetary or solar missions. (author)

  11. Physical design of the positron induced auger electron spectrometer

    International Nuclear Information System (INIS)

    Qin Xiubo; Jiang Xiaopan; Wang Ping; Yu Runsheng; Wang Baoyi; Wei Long

    2009-01-01

    Positron Annihilation Induced Auger Electron Spectroscopy (PAES) has several advantages over those excited by X-rays, high energy electrons or neutrons, such as excellent surface selectivity, high signal-to-noise ratio, low radiation damage,etc. A physical design of time of flight PAES (TOF-PAES) apparatus based on the Beijing Intense Slow Positron Beam (BIPB) is described in this paper. The positrons and electrons are transported in a 4 x 10 -3 T uniform magnetic field, and the gradient of magnetic field is designed to pluralize the Auger electrons emitted with 2π angle. The Auger electron energy is adjusted by a Faraday cage to optimize the energy resolution,which can be better than 2 eV. (authors)

  12. In-beam electron spectrometer used in conjunction with a gas-filled recoil separator

    International Nuclear Information System (INIS)

    Kankaanpaeae, H.; Butler, P.A.; Greenlees, P.T.; Bastin, J.E.; Herzberg, R.D.; Humphreys, R.D.; Jones, G.D.; Jones, P.; Julin, R.; Keenan, A.; Kettunen, H.; Leino, M.; Miettinen, L.; Page, T.; Rahkila, P.; Scholey, C.; Uusitalo, J.

    2004-01-01

    The conversion-electron spectrometer SACRED has been redesigned for use in conjunction with the RITU gas-filled recoil separator. The system allows in-beam recoil-decay-tagging (RDT) measurements of internal conversion electrons. The performance of the system using standard sources and in-beam is described

  13. Development and commissioning of a double-prism spectrometer for the diagnosis of femtosecond electron bunches

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, Steffen

    2016-12-15

    Free-electron lasers as accelerator-driven light sources and wakefield-based acceleration in plasmas require the knowledge of the longitudinal extension and the longitudinal current profile of the involved electron bunches. These bunches can yield lengths below 10 μm, or durations shorter than approx. 33 fs, as well as charges less than 30 pC. During this work, transition radiation from relativistic electron bunches was investigated in the mid-infrared wavelength regime. A spectrometer using an arrangement of two consecutive zinc selenide prisms was developed, built and commissioned. The instrument covers the spectral range from 2 μm to 18 μm in a single shot. Measurements with the double-prism spectrometer were conducted at the FEL facilities FLASH at DESY in Hamburg, Germany and FELIX at the Radboud Universiteit in Nijmegen, The Netherlands. The assessment of the spectrometer and comparative studies with established diagnostic devices at FLASH show high signal-to-noise ratios at bunch charges below 10 pC and confirm the obtained results.

  14. Field electron emission spectrometer combined with field ion/electron microscope as a field emission laboratory

    International Nuclear Information System (INIS)

    Shkuratov, S.I.; Ivanov, S.N.; Shilimanov, S.N.

    1996-01-01

    The facility, combining the field ion microscope, field electron emission microscope and field electron emission spectrometer, is described. Combination of three methodologies makes it possible to carry out the complete cycle of emission studies. Atom-plane and clean surface of the studied samples is prepared by means of field evaporation of the material atom layers without any thermal and radiation impact. This enables the study of atom and electron structure of clean surface of the wide range materials, the study whereof through the field emission methods was previously rather difficult. The temperature of the samples under study changes from 75 up to 2500 K. The energy resolution of the electron analyzer equals 30 MeV. 19 refs., 10 figs

  15. Proceedings of the 3rd workshop on balloon-borne experiments with superconducting magnet spectrometers

    International Nuclear Information System (INIS)

    Yamamoto, Akira

    1992-04-01

    The Third Work Shop on Balloon Borne Experiment with a Superconducting Magnet Spectrometer was held at National Laboratory for High Energy Physics (KEK), Tsukuba, Japan on February 24 - 25, 1992. The main effort for this workshop was focused on the progress of the BESS (Balloon Borne Experiment with a Superconducting Spectrometer) experiment and on the scope for scientific investigation with the BESS detector. The progress was reviewed and further investigation was discussed for the BESS further scientific collaboration among Univ. of Tokyo, Kobe University, KEK, ISAS and NMSU. (J.P.N.)

  16. DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers

    Science.gov (United States)

    Fan, Non Q.; Clarke, John

    1993-01-01

    A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced.

  17. Electrostatic systems used for the multipassage magnetic mass spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Berger, C; Baril, M

    1987-08-15

    Improvement in the power of resolution is desirable in the multiplication of passages in magnetic fields; our guiding principle is to carry out the operation using a single magnetic prism. In the multipassage process the ions must first turn back after leaving the prism. This turnback is obtained by an electrostatic mirror. We obtain a large enough number of passages by placing two mirrors and two systems with time-varying roles at right angles. These systems are referred to as lens-mirror 1. When they act as mirrors, they enable the particles to circulate in a closed circuit; when they act as lenses, they enable the particles to enter the circuit or leave it. The coupling of two multipassage spectrometers is momentarily possible thanks to lens-mirror 2. The function change results from a change in electrode potential. The requirements for these electrostatic systems and their construction are studied.

  18. A 4π tracking TPC magnetic spectrometer for RHIC

    International Nuclear Information System (INIS)

    Danby, G.; Eiseman, S.E.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Van Dijk, J.H.; Lindenbaum, S.J.; Chan, C.S.; Kramer, M.A.; Zhao, K.; Biswas, N.; Kenney, P.; Piekarz, J.; Adams, D.L.; Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Corcoran, M.D.; Empl, T.; Miettinen, H.E.; Mutchler, G.S.; Roberts, J.B.; Skeens, J.

    1990-01-01

    The primary physics objective of the 4π TPC magnetic spectrometer proposal is to search for the Quark-Gluon Plasma. In previous workshops we have discussed what the possible hadronic signatures of such a state of matter would be. Succinctly, the QGP is a direct prediction of non-perturbative QCD. Therefore the question of the existence of this new state of matter bears directly on the validity of non-perturbative QCD. However, since non-perturbative QCD has never been established, it is apparent that what may await us is a host of new phenomena that will go beyond the standard model

  19. The Omega spectrometer in the West Hall.

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    Inside the hut which sits on top of the superconducting magnet are the TV cameras that observe the particle events occurring in the spark chambers in the magnet gap below. On the background the two beam lines feeding the spectrometer target, for separated hadrons up to 40 GeV, on the right, for 80 GeV electrons, on the left, respectively. The latter strikes a radiator thus sending into Omega tagged photons up to 80 GeV. On the foreground, the two sections of the large gas Cerenkov counter working at atmospheric pressure, used for trigger purpose.

  20. HELIOS: A high intensity chopper spectrometer at LANSCE

    International Nuclear Information System (INIS)

    Mason, T.E.; Broholm, C.; Fultz, B.

    1998-01-01

    A proposal to construct a high intensity chopper spectrometer at LANSCE as part of the SPSS upgrade project is discussed. HELIOS will be optimized for science requiring high sensitivity neutron spectroscopy. This includes studies of phonon density of states in small polycrystalline samples, magnetic excitations in quantum magnets and highly correlated electron systems, as well as parametric studies (as a function of pressure, temperature, or magnetic field) of S(Q,ω). By employing a compact design together with the use of supermirror guide in the incident flight path the neutron flux at HELIOS will be significantly higher than any other comparable instrument now operating

  1. HELIOS: A high intensity chopper spectrometer at LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Mason, T.E. [Oak Ridge National Lab., TN (United States); Broholm, C. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Physics and Astronomy; Fultz, B. [California Inst. of Tech., Pasadena, CA (United States). Dept. of Materials Science] [and others

    1998-12-31

    A proposal to construct a high intensity chopper spectrometer at LANSCE as part of the SPSS upgrade project is discussed. HELIOS will be optimized for science requiring high sensitivity neutron spectroscopy. This includes studies of phonon density of states in small polycrystalline samples, magnetic excitations in quantum magnets and highly correlated electron systems, as well as parametric studies (as a function of pressure, temperature, or magnetic field) of S(Q,{omega}). By employing a compact design together with the use of supermirror guide in the incident flight path the neutron flux at HELIOS will be significantly higher than any other comparable instrument now operating.

  2. Effect of a spectrometer magnet on the beam-beam interaction

    International Nuclear Information System (INIS)

    Cornacchia, M.; Parzen, G.

    1981-01-01

    The presence of experimental apparatus in the interaction regions of an intersecting beam accelerator changes the configuration of the crossing beams. This changes the space-charge forces with respect to the standard, magnet-free crossing. The question is: what is the maximum allowable perturbation caused by the spectrometer magnet that can be tolerated from the point of view of the beam dynamics. This paper is limited to the perturbations that the curved trajectories cause the beam-beam space charge nonlinearities. The question has arisen of how one defines the strength of the perturbation. The only solution is to compute the strength of the most important nonlinear resources. In what follows, the computational method used in calculating these resonances is described, and compared with those induced by random orbit errors

  3. Effect of a spectrometer magnet on the beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Cornacchia, M; Parzen, G

    1981-01-01

    The presence of experimental apparatus in the interaction regions of an intersecting beam accelerator changes the configuration of the crossing beams. This changes the space-charge forces with respect to the standard, magnet-free crossing. The question is: what is the maximum allowable perturbation caused by the spectrometer magnet that can be tolerated from the point of view of the beam dynamics. This paper is limited to the perturbations that the curved trajectories cause the beam-beam space charge nonlinearities. The question has arisen of how one defines the strength of the perturbation. The only solution is to compute the strength of the most important nonlinear resources. In what follows, the computational method used in calculating these resonances is described, and compared with those induced by random orbit errors.

  4. Runaway electrons and magnetic island confinement

    International Nuclear Information System (INIS)

    Boozer, Allen H.

    2016-01-01

    The breakup of magnetic surfaces is a central feature of ITER planning for the avoidance of damage due to runaway electrons. Rapid thermal quenches, which lead to large accelerating voltages, are thought to be due to magnetic surface breakup. Impurity injection to avoid and to mitigate both halo and runaway electron currents utilizes massive gas injection or shattered pellets. The actual deposition is away from the plasma center, and the breakup of magnetic surfaces is thought to spread the effects of the impurities across the plasma cross section. The breakup of magnetic surfaces would prevent runaway electrons from reaching relativistic energies were it not for the persistence of non-intercepting flux tubes. These are tubes of magnetic field lines that do not intercept the walls. In simulations and in magnetic field models, non-intercepting flux tubes are found to persist near the magnetic axis and in the cores of magnetic islands even when a large scale magnetic surface breakup occurs. As long as a few magnetic surfaces reform before all of the non-intercepting flux tubes dissipate, energetic electrons confined and accelerated in these flux tubes can serve as the seed electrons for a transfer of the overall plasma current from thermal to relativistic carriers. The acceleration of electrons is particularly strong because of the sudden changes in the poloidal flux that naturally occur in a rapid magnetic relaxation. The physics of magnetic islands as non-intercepting flux tubes is studied. Expressions are derived for (1) the size of islands required to confine energetic runaway electrons, (2) the accelerating electric field in an island, (3) the increase or reduction in the size of an island by the runaway electron current, (4) the approximate magnitude of the runaway current in an island, and (5) the time scale for the evolution of an island.

  5. Runaway electrons and magnetic island confinement

    Energy Technology Data Exchange (ETDEWEB)

    Boozer, Allen H., E-mail: ahb17@columbia.edu [Columbia University, New York, New York 10027 (United States)

    2016-08-15

    The breakup of magnetic surfaces is a central feature of ITER planning for the avoidance of damage due to runaway electrons. Rapid thermal quenches, which lead to large accelerating voltages, are thought to be due to magnetic surface breakup. Impurity injection to avoid and to mitigate both halo and runaway electron currents utilizes massive gas injection or shattered pellets. The actual deposition is away from the plasma center, and the breakup of magnetic surfaces is thought to spread the effects of the impurities across the plasma cross section. The breakup of magnetic surfaces would prevent runaway electrons from reaching relativistic energies were it not for the persistence of non-intercepting flux tubes. These are tubes of magnetic field lines that do not intercept the walls. In simulations and in magnetic field models, non-intercepting flux tubes are found to persist near the magnetic axis and in the cores of magnetic islands even when a large scale magnetic surface breakup occurs. As long as a few magnetic surfaces reform before all of the non-intercepting flux tubes dissipate, energetic electrons confined and accelerated in these flux tubes can serve as the seed electrons for a transfer of the overall plasma current from thermal to relativistic carriers. The acceleration of electrons is particularly strong because of the sudden changes in the poloidal flux that naturally occur in a rapid magnetic relaxation. The physics of magnetic islands as non-intercepting flux tubes is studied. Expressions are derived for (1) the size of islands required to confine energetic runaway electrons, (2) the accelerating electric field in an island, (3) the increase or reduction in the size of an island by the runaway electron current, (4) the approximate magnitude of the runaway current in an island, and (5) the time scale for the evolution of an island.

  6. [A high resolution projection electron spectrometers]: Final report 1978-1987

    International Nuclear Information System (INIS)

    1988-01-01

    The main emphasis of the work has been to study inner shell ionization processes. The signatures have been K x-rays or K Auger transitions. We have worked with semiconductor or Bragg x-ray spectrometers. Toward the end of the contract we concentrated on projectile electron spectroscopy. These topics and other atomic physics projects are described briefly in this progress report

  7. High performance gamma-ray spectrometer for runaway electron studies on the FT-2 tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Shevelev, A.E., E-mail: Shevelev@cycla.ioffe.ru [Ioffe Institute, Politekhnicheskaya 26, St. Petersburg 194021 (Russian Federation); Khilkevitch, E.M.; Lashkul, S.I.; Rozhdestvensky, V.V.; Altukhov, A.B.; Chugunov, I.N.; Doinikov, D.N.; Esipov, L.A.; Gin, D.B.; Iliasova, M.V.; Naidenov, V.O.; Nersesyan, N.S.; Polunovsky, I.A.; Sidorov, A.V. [Ioffe Institute, Politekhnicheskaya 26, St. Petersburg 194021 (Russian Federation); Kiptily, V.G. [CCFE, Culham Science Centre, Abingdon, Oxon X14 3DB (United Kingdom)

    2016-09-11

    A gamma-ray spectrometer based on LaBr{sub 3}(Ce) scintillator has been used for measurements of hard X-ray emission generated by runaway electrons in the FT-2 tokamak plasmas. Using of the fast LaBr{sub 3}(Ce) has allowed extending count rate range of the spectrometer by a factor of 10. A developed digital processing algorithm of the detector signal recorded with a digitizer sampling rate of 250 MHz has provided a pulse height analysis at count rates up to 10{sup 7} s{sup −1}. A spectrum deconvolution code DeGaSum has been applied for inferring the energy distribution of runaway electrons escaping from the plasma and interacting with materials of the FT-2 limiter in the vacuum chamber. The developed digital signal processing technique for LaBr{sub 3}(Ce) spectrometer has allowed studying the evolution of runaways energy distribution in the FT-2 plasma discharges with time resolution of 1–5 ms.

  8. Lessons Learned for the MICE Coupling Solenoid from the MICE Spectrometer Solenoids

    International Nuclear Information System (INIS)

    Green, Michael A.; Wang, Li; Pan, Heng; Wu, Hong; Guo, Xinglong; Li, S.Y.; Zheng, S.X.; Virostek, Steve P.; DeMello, Allen J.; Li, Derun; Trillaud, Frederick; Zisman, Michael S.

    2010-01-01

    Tests of the spectrometer solenoids have taught us some important lessons. The spectrometer magnet lessons learned fall into two broad categories that involve the two stages of the coolers that are used to cool the magnets. On the first spectrometer magnet, the problems were centered on the connection of the cooler 2nd-stage to the magnet cold mass. On the first test of the second spectrometer magnet, the problems were centered on the cooler 1st-stage temperature and its effect on the operation of the HTS leads. The second time the second spectrometer magnet was tested; the cooling to the cold mass was still not adequate. The cryogenic designs of the MICE and MuCOOL coupling magnets are quite different, but the lessons learned from the tests of the spectrometer magnets have affected the design of the coupling magnets.

  9. The H1 forward muon spectrometer

    International Nuclear Information System (INIS)

    Kenyon, I.R.; Phillips, H.; Cronstroem, H.I.; Hedberg, V.; Jacobsson, C.; Joensson, L.; Lohmander, H.; Nyberg, M.; Biddulph, P.; Finnegan, P.; Foster, J.; Gilbert, S.; Hilton, C.; Ibbotson, M.; Mehta, A.; Sutton, P.; Stephens, K.; Thompson, R.

    1993-02-01

    The H1 detector started taking data at the electron- proton collider HERA in the beginning of 1992. In HERA 30 GeV electrons collide with 820 GeV protons giving a strong boost of the centre-of-mass system in the direction of the proton, also called the forward region. For the detection of high momentum muons in this region a muon spectrometer has been constructed, consisting of six drift chamber planes, three either side of a toroidal magnet. A first brief description of the system and its main parameters as well as the principles for track reconstruction and Τ 0 determination is given. (orig.)

  10. 2D electron systems viewed through an RF spectrometer

    International Nuclear Information System (INIS)

    Andrei, E.Y.

    1994-01-01

    Electrons trapped at the liquid helium-vacuum interface are an almost ideal realization of a 2D electron system. I will describe experiments probing the in-plane as well as the out-of-plane motion of the electrons. The former have emphasized the dynamics and thermodynamics of the electronic motion within the plane to understand the nature of the liquid-solid transition and to outline its phase boundary. The latter have studied the escape out of the electron layer and provided an opportunity to observe tunneling in a clean and well-characterized system as well as to measure the effects of correlations on the tunneling process. More recently experiments in the presence of a magnetic field transverse to the direction of tunneling have revealed several novel phenomena associated with the magnetic coupling between the in-plane and the out-of-plane electronic motions. Together, these experiments helped uncover the multi-faceted physics that can be found in this system. (orig.)

  11. A 4π tracking magnetic spectrometer for RHIC

    International Nuclear Information System (INIS)

    Lindenbaum, S.J.

    1988-01-01

    A tracking magnetic spectrometer based on large Time Projection Chambers (TPC) was previously proposed to measure the momentum of charged particles emerging from the RHIC beam pipe at angles larger than four degrees and to identify the particle type for those beyond fifteen degrees with momenta up to 700 MeV/c, which is a large fraction of the final charged particles emitted by a low cm rapidity quark-gluon plasma. Experimental progress in the successful performance of a TPC developed for AGS E-810 is reported. We have also included typical results of our event generator which contains an interface of an improved HIJET and a plasma bubble model. Typical plasma signals one can expect from this model are presented. 4 refs., 9 figs

  12. Electrostatic electron spectrometer based on two cylinders without axial symmetry

    International Nuclear Information System (INIS)

    Varga, D.; Toekesi, K.

    2005-01-01

    Complete text of publication follows. During the last decades electrostatic analyzers were widely used in atomic and surface physics. This was due to their good focusing and dispersion properties, The cylindrical mirror analyzer (CMA) is one of the most advantageous electrostatic analyzers. Its second order focusing properties have been calculated by many authors. A modified, so called 'box' type, CMA (ESA-13) is described in ref. [1]. For CMA (ESA-13), the position of the electron source and focus are outside the analyzer which is desirable for practical reasons. The ends of the cylinders are closed with two coaxial discs, therefore the electrostatic field near the edge is distorted compared to the logarithmic field existing in the classical 'in-finite' cylindrical mirror analyzer. However, the 'box' type distorted field cylindrical mirror analyzer geometry contains several limitations regarding the irradiation of the sample. Therefore, the construction of these analyzers was changed by replacing the endings of the analyzer with conically shaped electrodes ensuring a better accessibility for excitation. But among the various experimental tasks many geometrical conditions arise that are different or that need different sizes compared with the previous ones. Therefore, in a practical point of view, it is extremely advantageous to have different variations of spectrometers. This allows us to choose the best solution for a given problem. In this work, we present electron-optical properties of a mirror type electrostatic electron spectrometer consisting of two cylinders with eccentricity (see Fig 1.), namely the Eccentric Cylindrical Mirror Analyzer (ECMA). The designed analyzer is a possible variation of CMA for measuring the energy distribution of electrons with high energy resolution or making an electron monocromator. It has been shown that the Eccentric Cylindrical Mirror Analyzer has second-order focusing properties with remarkable dispersion (see Fig 2

  13. Photoelectron spectrometer for high-resolution angular resolved studies

    International Nuclear Information System (INIS)

    Parr, A.C.; Southworth, S.H.; Dehmer, J.L.; Holland, D.M.P.

    1982-01-01

    We report on a new electron spectrometer system designed for use on storage-ring light sources. The system features a large (76 cm dia. x 92 cm long) triply magnetically shielded vacuum chamber and two 10.2 cm mean radius hemispherical electron-energy analyzers. One of the analyzers is fixed and the other is rotatable through about 150 0 . The chamber is pumped by a cryopump and a turbomolecular pump combination so as to enable experiments with a variety of gases under different conditions. The light detection includes both a direct beam monitor and polarization analyzer. The electron detection is accomplished with either a continuous-channel electron multiplier or with multichannel arrays used as area detectors

  14. Description and performance of an electron-ion coincidence TOF spectrometer used at the Brazilian synchrotron facility LNLS

    International Nuclear Information System (INIS)

    Burmeister, F.; Coutinho, L.H.; Marinho, R.R.T.; Homem, M.G.P.; Morais, M.A.A. de; Mocellin, A.; Bjoerneholm, O.; Sorensen, S.L.; Fonseca, P.T.; Lindgren, A.; Naves de Brito, A.

    2010-01-01

    This paper reports the characteristics and performance of a Time-of-Flight Mass Spectrometer (TOF-MS) for coincidence measurements between electrons and ions that has been developed jointly in Sweden and Brazil. The spectrometer, used for studies of inner-shell photoexcitation of molecules in the gas-phase, has been optimized by implementing ion and electron lenses to allow the use of relatively small diameter detectors. Simulations were performed to understand the lens performance and they show that ions (electrons) could be collected without angular discrimination with a maximum kinetic energy up to ten (two) times higher than without the lens actions. A rotary vacuum chamber allows the spectrometer axis to be positioned at different angles relative to the polarization vector of the excitation beam. An important characteristic of the apparatus is that the acquisition setup allows a multi-hit capability with 1 ns resolution. Hereby, Photoelectron-Photoion-Photoion Coincidence (PEPIPICO) measurements can be performed on molecules containing two or more atoms of equal mass. A method to obtain experimental detection efficiencies of a single ion and one of one, two or three electrons has been developed. A systematic study of the interaction region has been performed to determine the shape of the photon and gas beams. Measurements on molecular nitrogen demonstrate the spectrometer's ability to resolve fragments with the same charge to mass ratio arriving within only a few ns. Simulations and experimental results of fragmentation of two singly charged cation nitrogen atoms agree, confirming that the spectrometer performance is well understood.

  15. Description and performance of an electron-ion coincidence TOF spectrometer used at the Brazilian synchrotron facility LNLS

    Energy Technology Data Exchange (ETDEWEB)

    Burmeister, F. [Laboratorio Nacional de Luz Sincrotron, 13084-971, Campinas, SP (Brazil); Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala (Sweden); Coutinho, L.H. [Laboratorio Nacional de Luz Sincrotron, 13084-971, Campinas, SP (Brazil); Instituto de Fisica, Universidade Estadual de Campinas, 13083-970 Campinas, SP (Brazil); Marinho, R.R.T. [Laboratorio Nacional de Luz Sincrotron, 13084-971, Campinas, SP (Brazil); Homem, M.G.P. [Departamento de Quimica, Universidade Federal de Sao Carlos, 13565-905 Sao Carlos, SP (Brazil); Morais, M.A.A. de; Mocellin, A. [Instituto de Fisica, Universidade de Brasilia, 70910-900 Brasilia, DF (Brazil); Bjoerneholm, O. [Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala (Sweden); Sorensen, S.L. [SLF, Institute of Physics, University of Lund, Box 118, S-221 00 Lund (Sweden); Fonseca, P.T. [Laboratorio Nacional de Luz Sincrotron, 13084-971, Campinas, SP (Brazil); Lindgren, A. [SLF, Institute of Physics, University of Lund, Box 118, S-221 00 Lund (Sweden); Naves de Brito, A., E-mail: arnaldo.naves@gmail.co [Laboratorio Nacional de Luz Sincrotron, 13084-971, Campinas, SP (Brazil); Instituto de Fisica, Universidade de Brasilia, 70910-900 Brasilia, DF (Brazil)

    2010-06-15

    This paper reports the characteristics and performance of a Time-of-Flight Mass Spectrometer (TOF-MS) for coincidence measurements between electrons and ions that has been developed jointly in Sweden and Brazil. The spectrometer, used for studies of inner-shell photoexcitation of molecules in the gas-phase, has been optimized by implementing ion and electron lenses to allow the use of relatively small diameter detectors. Simulations were performed to understand the lens performance and they show that ions (electrons) could be collected without angular discrimination with a maximum kinetic energy up to ten (two) times higher than without the lens actions. A rotary vacuum chamber allows the spectrometer axis to be positioned at different angles relative to the polarization vector of the excitation beam. An important characteristic of the apparatus is that the acquisition setup allows a multi-hit capability with 1 ns resolution. Hereby, Photoelectron-Photoion-Photoion Coincidence (PEPIPICO) measurements can be performed on molecules containing two or more atoms of equal mass. A method to obtain experimental detection efficiencies of a single ion and one of one, two or three electrons has been developed. A systematic study of the interaction region has been performed to determine the shape of the photon and gas beams. Measurements on molecular nitrogen demonstrate the spectrometer's ability to resolve fragments with the same charge to mass ratio arriving within only a few ns. Simulations and experimental results of fragmentation of two singly charged cation nitrogen atoms agree, confirming that the spectrometer performance is well understood.

  16. Detector tests in a high magnetic field and muon spectrometer triggering studies on a small prototype for an LHC experiment

    CERN Document Server

    Ambrosi, G; Basile, M; Battiston, R; Bergsma, F; Castro, H; Cifarelli, Luisa; Cindolo, F; Contin, A; De Pasquale, S; Gálvez, J; Gentile, S; Giusti, P; Laurent, G; Levi, G; Lin, Q; Maccarrone, G D; Mattern, D; Nania, R; Rivera, F; Schioppa, M; Sharma, A; CERN. Geneva. Detector Research and Development Committee

    1990-01-01

    The "Large Area Devices" group of the LAA project is working on R&D for muon detection at a future super-collider. New detectors are under development and the design of a muon spectrometer for an LHC experiment is under study. Our present choice is for a compact, high field, air-core toroidal muon spectrometer. Good momentum resolution is achievable in this compact solution, with at least one plane of detection elements inside the high field region. A new detector, the Blade Chamber, making use of blades instead of wires, has been developed for the forward and backward regions of the spectrometer, where polar coordinate readings are desirable.The assembling of a CERN high energy beam line, equipped with high resolution drift chambers and a strong field magnet could give us the opportunity to test our chambers in a high magnetic field and to study the muon trigger capabilities of a spectrometer, like the one proposed, on a small prototype.

  17. Spectrometer for X-ray emission experiments at FERMI free-electron-laser

    International Nuclear Information System (INIS)

    Poletto, L.; Frassetto, F.; Miotti, P.; Di Cicco, A.; Iesari, F.; Finetti, P.; Grazioli, C.; Kivimäki, A.; Stagira, S.; Coreno, M.

    2014-01-01

    A portable and compact photon spectrometer to be used for photon in-photon out experiments, in particular x-ray emission spectroscopy, is presented. The instrument operates in the 25–800 eV energy range to cover the full emissions of the FEL1 and FEL2 stages of FERMI. The optical design consists of two interchangeable spherical varied-lined-spaced gratings and a CCD detector. Different input sections can be accommodated, with/without an entrance slit and with/without an additional relay mirror, that allow to mount the spectrometer in different end-stations and at variable distances from the target area both at synchrotron and at free-electron-laser beamlines. The characterization on the Gas Phase beamline at ELETTRA Synchrotron (Italy) is presented

  18. The Omega spectrometer

    CERN Multimedia

    1972-01-01

    The Omega spectrometer which came into action during the year. An array of optical spark chambers can be seen withdrawn from the magnet aperture. In the 'igloo' above the magnet is located the Plumbicon camera system which collects information from the spark chambers.

  19. Magnetism in heavy-electron metals

    International Nuclear Information System (INIS)

    Ott, H.R.

    1997-01-01

    Originally it was believed that the presence of heavy-mass charge carriers at low temperatures in some special rare-earth or actinide compounds was simply the result of a suppression of magnetic order in these materials. Various experiments reveal, however, that magnetic order may occur from a heavy-electron state or that a heavy-electron state may also develop within a magnetically ordered materix. It turned out that pure compounds without any sign of a cooperative phase transition down to very low temperatures are rare but examples are known where microscopic experimental probes give evidence for strong magnetic correlations involving moments of much reduced magnitude (≤ 0.1μ Β ) in such cases. It apperas that electronic and magnetic inhomogeneities, both in real and reciprocal space occur which are not simply the result of chemical inhomogeneities. Long range magnetic order among strongly reduced magnetic moments seems to be a particular feature of some heavy-electron materials. Other examples show, that disorder may lead to a suppression of cooperative phase transitions and both macroscopic and microscopic physical properties indicate that conservative model calculations are not sufficient to describe the experimental observations. The main difficulty is to find a suitable theoretical approach that considers the various interactions of similar strength on an equal footing. Different examples of these various features are demonstrated and discussed. (au)

  20. Antimatter search with AMS (Alpha Magnetic Spectrometer) during STS-91 precursor flight

    International Nuclear Information System (INIS)

    Alpat, Behcet

    2000-01-01

    The Alpha Magnetic Spectrometer (AMS) is designed to study the antimatter, matter and dark matter in space. AMS successfully flown on space shuttle Discovery during precursor flight STS-91 in a 51.7 degree sign orbit at altitudes between 320 and 390 km. No antimatter nuclei with Z ≥ 2 were detected. In this report we present the AMS performances during shuttle flight and we give new limits on antimatter/matter flux ratio

  1. The Dipole Magnet Design for the ALICE DiMuon Arm Spectrometer

    CERN Document Server

    Akishin, P G; Blinov, N; Boguslavsky, I V; Cacaut, D E; Danilov, V; Datskov, V I; Golubitsky, O M; Kalimov, A; Kochournikov, E; Lyubimtsev, A; Makarov, A; Mikhailov, K; Olex, I; Popov, V; Semashko, S; Shabunov, A; Shishov, Yu A; Shurygin, A; Shurygina, M; Sissakian, A N; Swoboda, Detlef; Vodopyanov, A S

    2002-01-01

    An essential part of the DiMuon Arm Spectrometer of the ALICE experiment is a conventional Dipole Magnet of about 890 tons which provides the bending power to measure the momenta of muons. The JINR engineering design of the Dipole Magnet, technical characteristics and description of the proposed manufacturing procedure are presented. The proposed Coil fabrication technique is based on winding of flat pancakes, which are subsequently bent on cylindrical mandrels. The pancakes are then stacked and cured with prepreg insulation. The method is demonstrated on hand of the prototype II, which consists of a pancake made with full-size aluminium conductor. Some details of electromagnetic and mechanical calculations are described. The results of measuring of mechanical and electrical characteristics of materials related to the coil composite structure are discussed.

  2. Magnetic irone oxide nanoparticles in photosynthetic systems

    International Nuclear Information System (INIS)

    Khalilov, R.I.; Nasibova, A.N.; Khomutov, G.B.

    2014-01-01

    Full text : It was found and studied the effect of biogenic formation of magnetic inclusions in photosynthetic systems - in various higher plants under the influence of some external stress factors (radiation impact, moisture deficit) and in a model system - a suspension of chloroplasts. For registration and characterization of magnetic nanoparticles in the samples used EPR spectrometer because superparamagnetic and ferromagnetic nanoparticles have a chcracteristic signals of electron magnetic resonance. For direct visualization of magnetic nanoparticles it was used the method of transmission electron microscopy

  3. Microprocessor system for data acquisition processing and display for Auger electrons spectrometer

    International Nuclear Information System (INIS)

    Pawlowski, Z.; Cudny, W.; Hildebrandt, S.; Marzec, J.; Walentek, J.; Zaremba, K.

    1984-01-01

    Data acquisition system for Auger electron spectrometry is developed. The system is used for chemical and structural analysis of materials and consists of a cylindrical mirror analyzer being a measuring spectrometer device, CAMAC unit and control unit. The control unit comprises a microcomputer based on INTEL 8080 microprocessor and display

  4. The source of monoenergetic electrons for the monitoring of spectrometer in the KATRIN neutrino experiment

    CERN Document Server

    Slezák, Martin

    The international project KATRIN (KArlsruhe TRItium Neutrino experiment) is a next-generation tritium $\\beta$-decay experiment. It is designed to measure the electron anti-neutrino mass by means of a unique electron spectrometer with sensitivity of 0.2 eV/c$^2$. This is an improvement of one order of magnitude over the last results. Important part of the measurement will rest in continuous precise monitoring of high voltage of the KATRIN main spectrometer. The monitoring will be done by means of conversion electrons emitted from a solid source based on $^{83}$Rb decay. Properties of several of these sources are studied in this thesis by means of the semiconductor $\\gamma$-ray spectroscopy. Firstly, measurement of precise energy of the 9.4 keV nuclear transition observed in $^{83}$Rb decay, from which the energy of conversion electrons is derived, is reported. Secondly, measurement of activity distribution of the solid sources by means of the Timepix detector is described. Finally, a report on measurement of r...

  5. Development of portable ESR spectrometer as a reader for alanine dosimeters

    International Nuclear Information System (INIS)

    Kojima, T.; Haruyama, Y.; Tachibana, H.; Tanaka, R.; Okamoto, J.

    1993-01-01

    A prototype portable electron spin resonance (ESR) spectrometer was designed and tested, and its feasibility as a reader of alanine dosimeters was studied from the two standpoints of reproducibility of readings and sensitivity sufficient for dosimetry in the absorbed dose range 1-100 kGy. It has two main components: a permanent magnet and resonator; and a unit box with a microwave and auto-frequency control (AFC) circuit, a sweep controller of magnetic field, display, etc. In the present preliminary study, reproducibility values are measured with the same ESR parameters and alanine-polystyrene (alanine-PS) dosimeter at a dose of 1 kGy: repeatedly measuring without removing dosimeter from the cavity; individual measurement with removing and inserting again into the cavity with readjustment of ESR parameters. Alanine/ESR dosimetry using this spectrometer has a measurable dose range from 1 to 100 kGy with relatively high precision within ± 3% (1σ) as a preliminary result. The portable ESR spectrometer may also be modified as an automatic, more precise, dedicated alanine dosimeter reader. (author)

  6. Periodic magnetic field as a polarized and focusing thermal neutron spectrometer and monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, J. T.; Williams, D. L.; Fuller, M. J.; Gary, C. K.; Piestrup, M. A. [Adelphi Technology, Inc., 2003 East Bayshore Rd., Redwood City, California 94063 (United States); Pantell, R. H.; Feinstein, J. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Flocchini, R. G.; Boussoufi, M.; Egbert, H. P.; Kloh, M. D.; Walker, R. B. [Davis McClellan Nuclear Radiation Center, University of California, McClellan, California 95652 (United States)

    2010-01-15

    A novel periodic magnetic field (PMF) optic is shown to act as a prism, lens, and polarizer for neutrons and particles with a magnetic dipole moment. The PMF has a two-dimensional field in the axial direction of neutron propagation. The PMF alternating magnetic field polarity provides strong gradients that cause separation of neutrons by wavelength axially and by spin state transversely. The spin-up neutrons exit the PMF with their magnetic spins aligned parallel to the PMF magnetic field, and are deflected upward and line focus at a fixed vertical height, proportional to the PMF period, at a downstream focal distance that increases with neutron energy. The PMF has no attenuation by absorption or scatter, as with material prisms or crystal monochromators. Embodiments of the PMF include neutron spectrometer or monochromator, and applications include neutron small angle scattering, crystallography, residual stress analysis, cross section measurements, and reflectometry. Presented are theory, experimental results, computer simulation, applications of the PMF, and comparison of its performance to Stern-Gerlach gradient devices and compound material and magnetic refractive prisms.

  7. Periodic magnetic field as a polarized and focusing thermal neutron spectrometer and monochromator.

    Science.gov (United States)

    Cremer, J T; Williams, D L; Fuller, M J; Gary, C K; Piestrup, M A; Pantell, R H; Feinstein, J; Flocchini, R G; Boussoufi, M; Egbert, H P; Kloh, M D; Walker, R B

    2010-01-01

    A novel periodic magnetic field (PMF) optic is shown to act as a prism, lens, and polarizer for neutrons and particles with a magnetic dipole moment. The PMF has a two-dimensional field in the axial direction of neutron propagation. The PMF alternating magnetic field polarity provides strong gradients that cause separation of neutrons by wavelength axially and by spin state transversely. The spin-up neutrons exit the PMF with their magnetic spins aligned parallel to the PMF magnetic field, and are deflected upward and line focus at a fixed vertical height, proportional to the PMF period, at a downstream focal distance that increases with neutron energy. The PMF has no attenuation by absorption or scatter, as with material prisms or crystal monochromators. Embodiments of the PMF include neutron spectrometer or monochromator, and applications include neutron small angle scattering, crystallography, residual stress analysis, cross section measurements, and reflectometry. Presented are theory, experimental results, computer simulation, applications of the PMF, and comparison of its performance to Stern-Gerlach gradient devices and compound material and magnetic refractive prisms.

  8. Construction of a NMR permanent magnet; Construcao de um ima permanente para RMN

    Energy Technology Data Exchange (ETDEWEB)

    Colnago, Luiz Alberto; Martins Neto, Ladislau; Oste, Rene de [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Nucleo de Pesquisa e Desenvolvimento de Instrumentacao Agropecuaria

    1992-12-31

    Viewing the development of the pulsed, low resolution NMR spectrometers for quantitative analysis, the electronic part of a NMR spectrometer has first been constructed, based on a 1.4 Tesla magnet of a 60 MHz Varian device, with a gap increased to 23 mm, therefore reducing the field to .66 Tesla (28 MHz for the hydrogen). For the complete construction of the spectrometer in Brazil, a permanent magnet for NMR has also been constructed 9 refs., 3 figs.

  9. Magnetic field measurement in the analyzing magnet of NIS spectrometer

    Science.gov (United States)

    Avramenko, S. A.; Afanas'ev, S. V.; Voloshina, I. G.; Dolgii, S. A.; Yusupov, A. Yu.; Kalmykov, A. V.; Makoveev, V. K.; Nikolaevskii, G. P.; Ostrovskii, I. V.; Perepelkin, E. E.; Peresedov, V. F.; Plyashkevich, S. N.; Rossiiskaya, N. S.; Salmin, R. A.; Spodarets, V. K.; Strokovskii, E. A.; Yudin, I. P.

    2006-12-01

    The main goals of the Nucleon Intrinsic Strangeness experiment (NIS) are the search for the effects of hidden polarized strangeness in the nucleon and the exploration and study of exotic baryons (pentaquarks) in NN reactions. The setup is located in the Laboratory of High Energies at the Joint Institute for Nuclear Research in channel 4V of the Nuclotron extracted beam with the energy between 1 and 4 GeV. The 1SP-40-4V electromagnet of the spectrometer has the external dimensions 3.20 × 3.26 × 4.48 m and the aperture 2.74 × 0.68 m. The magnetic field measurement was performed using the three-component Hall magnetometer in the computer-controlled automated mode. The volume of measurements was 1.03 × 0.60 × 3.92 m. The description of the measuring equipment and measurement procedure is given. The results of the measurements are used for the Monte Carlo computer modeling of the experiment. These results will be used in the analysis of physical data after their acquisition.

  10. Large solid angle tracking of Monte Carlo events of heavy ion collisions in TPC magnetic spectrometers

    International Nuclear Information System (INIS)

    Lindenbaum, S.J.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Asoka-Kumar, P.P.V.; Chan, C.S.; Kramer, M.A.

    1987-01-01

    The BNL/CCNY collaboration has for some time had as its goal the development and use of ≅ 4π solid angle magnetic spectrometer tracking of charged particles produced in heavy ion collision experiments at AGS, and eventually RHIC. (orig./HSI)

  11. Magnetization effects in electron cooling

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Skrinskii, A.N.

    A study is made of cooling in an electron beam which is accompanied by a strong magnetic field and a longitudinal temperature low compared to the transverse temperature. It is shown that the combination of two factors--magnetization and low longitudinal temperature of electrons--can sharply increase the cooling rate of a heavy-particle beam when the velocity spread is smaller than the transverse spread of electron velocities and reduce its temperature to the longitudinal temperature of the electrons, which is lower than that of the cathode by several orders of magnitude

  12. Proof of Concept Coded Aperture Miniature Mass Spectrometer Using a Cycloidal Sector Mass Analyzer, a Carbon Nanotube (CNT) Field Emission Electron Ionization Source, and an Array Detector

    Science.gov (United States)

    Amsden, Jason J.; Herr, Philip J.; Landry, David M. W.; Kim, William; Vyas, Raul; Parker, Charles B.; Kirley, Matthew P.; Keil, Adam D.; Gilchrist, Kristin H.; Radauscher, Erich J.; Hall, Stephen D.; Carlson, James B.; Baldasaro, Nicholas; Stokes, David; Di Dona, Shane T.; Russell, Zachary E.; Grego, Sonia; Edwards, Steven J.; Sperline, Roger P.; Denton, M. Bonner; Stoner, Brian R.; Gehm, Michael E.; Glass, Jeffrey T.

    2018-02-01

    Despite many potential applications, miniature mass spectrometers have had limited adoption in the field due to the tradeoff between throughput and resolution that limits their performance relative to laboratory instruments. Recently, a solution to this tradeoff has been demonstrated by using spatially coded apertures in magnetic sector mass spectrometers, enabling throughput and signal-to-background improvements of greater than an order of magnitude with no loss of resolution. This paper describes a proof of concept demonstration of a cycloidal coded aperture miniature mass spectrometer (C-CAMMS) demonstrating use of spatially coded apertures in a cycloidal sector mass analyzer for the first time. C-CAMMS also incorporates a miniature carbon nanotube (CNT) field emission electron ionization source and a capacitive transimpedance amplifier (CTIA) ion array detector. Results confirm the cycloidal mass analyzer's compatibility with aperture coding. A >10× increase in throughput was achieved without loss of resolution compared with a single slit instrument. Several areas where additional improvement can be realized are identified.

  13. Effects of geometry in itinerant electron magnets

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan); Muro, Y [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan); Kohara, T [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan); Shiga, M [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2007-04-11

    The magnetism of quasi-one-dimensional itinerant electron magnets RMn{sub 4}Al{sub 8} is compared with that of the typical frustrated itinerant electron magnet YMn{sub 2}. The possible formation and observation of the spin pseudogap are discussed in connection with the spin-liquid state in strongly correlated itinerant electron systems.

  14. Electron spectrometer for measurement of the energy distributions and angular distributions of electrons ejected by ionizing radiation

    International Nuclear Information System (INIS)

    Dehmer, J.L.

    1975-01-01

    With a broad range of applications in mind, a new electron spectrometer has been constructed which is flange mountable, has an easily accessible source region, is rotatable over the range 25 0 less than or equal to theta less than or equal to 335 0 , and has a wide dynamical range and a wide range of resolving power

  15. A Ku band pulsed electron paramagnetic resonance spectrometer using an arbitrary waveform generator for quantum control experiments at millikelvin temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yap, Yung Szen, E-mail: yungszen@utm.my [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka-shi, Osaka 560-8531 (Japan); Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Tabuchi, Yutaka [Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan); Negoro, Makoto; Kagawa, Akinori; Kitagawa, Masahiro, E-mail: kitagawa@ee.es.osaka-u.ac.jp [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka-shi, Osaka 560-8531 (Japan)

    2015-06-15

    We present a 17 GHz (Ku band) arbitrary waveform pulsed electron paramagnetic resonance spectrometer for experiments down to millikelvin temperatures. The spectrometer is located at room temperature, while the resonator is placed either in a room temperature magnet or inside a cryogen-free dilution refrigerator; the operating temperature range of the dilution unit is from ca. 10 mK to 8 K. This combination provides the opportunity to perform quantum control experiments on electron spins in the pure-state regime. At 0.6 T, spin echo experiments were carried out using γ-irradiated quartz glass from 1 K to 12.3 mK. With decreasing temperatures, we observed an increase in spin echo signal intensities due to increasing spin polarizations, in accordance with theoretical predictions. Through experimental data fitting, thermal spin polarization at 100 mK was estimated to be at least 99%, which was almost pure state. Next, to demonstrate the ability to create arbitrary waveform pulses, we generate a shaped pulse by superposing three Gaussian pulses of different frequencies. The resulting pulse was able to selectively and coherently excite three different spin packets simultaneously—a useful ability for analyzing multi-spin system and for controlling a multi-qubit quantum computer. By applying this pulse to the inhomogeneously broadened sample, we obtain three well-resolved excitations at 8 K, 1 K, and 14 mK.

  16. A new time of flight mass spectrometer for absolute dissociative electron attachment cross-section measurements in gas phase

    Science.gov (United States)

    Chakraborty, Dipayan; Nag, Pamir; Nandi, Dhananjay

    2018-02-01

    A new time of flight mass spectrometer (TOFMS) has been developed to study the absolute dissociative electron attachment (DEA) cross section using a relative flow technique of a wide variety of molecules in gas phase, ranging from simple diatomic to complex biomolecules. Unlike the Wiley-McLaren type TOFMS, here the total ion collection condition has been achieved without compromising the mass resolution by introducing a field free drift region after the lensing arrangement. The field free interaction region is provided for low energy electron molecule collision studies. The spectrometer can be used to study a wide range of masses (H- ion to few hundreds atomic mass unit). The mass resolution capability of the spectrometer has been checked experimentally by measuring the mass spectra of fragment anions arising from DEA to methanol. Overall performance of the spectrometer has been tested by measuring the absolute DEA cross section of the ground state SO2 molecule, and the results are satisfactory.

  17. Quadrupole magnetic mapping of the high resolution spectrometers of Thomas Jefferson National Accelerator Laboratory, Hall A. (Q.M.M. project: Quadrupole Magnetic Measurement)

    International Nuclear Information System (INIS)

    Quemener, Gilles

    1997-01-01

    This thesis describes the magnetic measurements that have been performed on the superconducting quadrupoles of the High Resolution Spectrometers of TJNAF, Hall A (USA), which are designed to measure particle momentum up to 4 GeV.c -1 with a σp/p = 10 -4 resolution. The mapping method is based on rotating coil technique, the originality being a segmentation of the probe along the quad axis. Together with an accurate magnet modelling, the measurement of the flux variations through the set of rotating coils allows to determine the magnetic field at each point. We use the 3D field formalism, i.e., the Fourier-Bessel expansion of the field obtained by solving the Laplace equation. We describe the QMM method and then the apparatus consisting in two probes of length 1.6 m and 3.2 m built to map the three quadrupoles Q1, Q2, Q3. Data processing uses Fourier analysis. The mapping of the Electron Arm took place in situ in 1996. A first set of results concerns integral measurements including the properties of excitation cycle of the magnets (saturation and hysteresis). Second set of results in terms of local field yields the 3D field maps of the quadrupoles. After having applied corrections to the data we obtain a local field accuracy of 5 Gauss on each component, i.e. an uncertainty of 5.10 -4 relative to the quadrupole central field. We use SNAKE ray-tracing code with the implementation of QMM field maps and obtain preliminary results on HRS optics. (author)

  18. Field and frequency modulated sub-THz electron spin resonance spectrometer

    Directory of Open Access Journals (Sweden)

    Christian Caspers

    2016-05-01

    Full Text Available 260-GHz radiation is used for a quasi-optical electron spin resonance (ESR spectrometer which features both field and frequency modulation. Free space propagation is used to implement Martin-Puplett interferometry with quasi-optical isolation, mirror beam focusing, and electronic polarization control. Computer-aided design and polarization pathway simulation lead to the design of a compact interferometer, featuring lateral dimensions less than a foot and high mechanical stability, with all components rated for power levels of several Watts suitable for gyrotron radiation. Benchmark results were obtained with ESR standards (BDPA, DPPH using field modulation. Original high-field ESR of 4f electrons in Sm3+-doped Ceria was detected using frequency modulation. Distinct combinations of field and modulation frequency reach a signal-to-noise ratio of 35 dB in spectra of BDPA, corresponding to a detection limit of about 1014 spins.

  19. Electron holography of magnetic field generated by a magnetic recording head.

    Science.gov (United States)

    Goto, Takayuki; Jeong, Jong Seok; Xia, Weixing; Akase, Zentaro; Shindo, Daisuke; Hirata, Kei

    2013-06-01

    The magnetic field generated by a magnetic recording head is evaluated using electron holography. A magnetic recording head, which is connected to an electric current source, is set on the specimen holder of a transmission electron microscope. Reconstructed phase images of the region around the magnetic pole show the change in the magnetic field distribution corresponding to the electric current applied to the coil of the head. A simulation of the magnetic field, which is conducted using the finite element method, reveals good agreement with the experimental observations.

  20. Lessons learned with the SAGE spectrometer

    International Nuclear Information System (INIS)

    Sorri, J; Greenlees, P T; Jones, P; Julin, R; Konki, J; Pakarinen, J; Rahkila, P; Sandzelius, M; Uusitalo, J; Papadakis, P; Cox, D M; Herzberg, R D

    2012-01-01

    The SAGE spectrometer combines a high-efficiency γ-ray detection system with an electron spectrometer. Some of the design features have been known to be problematic and surprises have come up during the early implementation of the spectrometer. Tests related to bismuth germanate Compton-suppression shields, electron detection efficiency and an improved cooling system are discussed in the paper. (paper)

  1. Testing of the SPEDE conversion electron spectrometer at ISOLDE

    CERN Document Server

    AUTHOR|(CDS)2157167

    2017-04-24

    The aim of this work was to test the performance of the SPEDE detector in the MINIBALL setup at CERN’s ISOLDE laboratory. The main research objective of MINIBALL is to study properties of atomic nuclei employing radioactive ion beams. Radioactive Bi-207 and Hg-191 were used in this experiment. SPEDE detects internal conversion electrons which are created in transitions between states in atomic nucleus. The internal conversion is competing process to more common γ-ray emission. This way it is possible to measure different properties of nuclear structure for example the E0-transitions. The simultaneous γ and electron measurements are possible when SPEDE is used in conjunction with the MINIBALL spectrometer. The GEANT4 simulation results were used to help interpretation of experimental results. As a result, αK/L-ratio was determined for Bi-207 conversion electrons, for the 5^2− -> 1^2− transition αK/L = 3.29±0.06 and for the 13^2+-> 5^2− transition αK/L = 3.11±0.05 were obtained. Also, the partial...

  2. An angular selective electron gun for the KATRIN experiment

    Energy Technology Data Exchange (ETDEWEB)

    Zacher, Michael; Ortjohann, Hans-Werner; Steinbrink, Nicholas; Josten, Lorenz; Hannen, Volker; Weinheimer, Christian; Winzen, Daniel [Westfaelische Wilhelms-Universitaet, Muenster (Germany); Collaboration: KATRIN-Collaboration

    2013-07-01

    The KArlsruhe TRItium Neutrino experiment aims for a measurement of the electron anti-neutrino mass with a sensitivity of 200 meV/c{sup 2} (95% C.L.) by analysing the endpoint region of the tritium β-decay. The main spectrometer (MAC-E filter type, 23m length) is one of the central parts of the experiment, featuring an energy resolution of Δ E<1 eV. For commissioning of the spectrometer a well defined electron source is needed that allows to determine the transmission characteristics and compare the electromagnetic properties to simulations. For this purpose an angular selective electron gun was developed. A pulsed UV-Laser produces electrons via the photo-electric effect, which are then accelerated electrostatically in a magnetic field. It features a small energy spread, a sharp selectable emission angle and covers the whole magnetic flux tube of KATRIN. By that, the characteristics of the spectrometer can be investigated with high precision. The time structure of the electron pulses allows time of flight measurements, offering enhanced sensitivity. The talk gives an overview about the e-gun design and its properties.

  3. Electron dynamics in inhomogeneous magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Nogaret, Alain, E-mail: A.R.Nogaret@bath.ac.u [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)

    2010-06-30

    This review explores the dynamics of two-dimensional electrons in magnetic potentials that vary on scales smaller than the mean free path. The physics of microscopically inhomogeneous magnetic fields relates to important fundamental problems in the fractional quantum Hall effect, superconductivity, spintronics and graphene physics and spins out promising applications which will be described here. After introducing the initial work done on electron localization in random magnetic fields, the experimental methods for fabricating magnetic potentials are presented. Drift-diffusion phenomena are then described, which include commensurability oscillations, magnetic channelling, resistance resonance effects and magnetic dots. We then review quantum phenomena in magnetic potentials including magnetic quantum wires, magnetic minibands in superlattices, rectification by snake states, quantum tunnelling and Klein tunnelling. The third part is devoted to spintronics in inhomogeneous magnetic fields. This covers spin filtering by magnetic field gradients and circular magnetic fields, electrically induced spin resonance, spin resonance fluorescence and coherent spin manipulation. (topical review)

  4. Electronic orbital angular momentum and magnetism of graphene

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Ji, E-mail: ji.luo@upr.edu

    2014-10-01

    Orbital angular momentum (OAM) of graphene electrons in a perpendicular magnetic field is calculated and corresponding magnetic moment is used to investigate the magnetism of perfect graphene. Variation in magnetization demonstrates its decrease with carrier-doping, plateaus in a large field, and de Haas–van Alphen oscillation. Regulation of graphene's magnetism by a parallel electric field is presented. The OAM originates from atomic-scale electronic motion in graphene lattice, and vector hopping interaction between carbon atomic orbitals is the building element. A comparison between OAM of graphene electrons, OAM of Dirac fermions, and total angular momentum of the latter demonstrates their different roles in graphene's magnetism. Applicability and relation to experiments of the results are discussed. - Highlights: • Orbital angular momentum of graphene electrons is calculated. • Orbital magnetic moment of graphene electrons is obtained. • Variation in magnetization of graphene is calculated. • Roles of different kinds of angular momentum are investigated.

  5. The Alpha Magnetic Spectrometer (AMS) experiment on the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Alpat, Behcet E-mail: behcet.alpat@pg.infn.it

    2001-04-01

    The Alpha Magnetic Spectrometer (AMS) is a detector designed to operate in space to search for antimatter components in cosmic ray, the annihilation products of darkmatter and to study the antiprotons, positrons and light nuclei. A 'baseline' version of the experiment has successfully completed the precursor flight on Space Shuttle Discovery (June 2-12, 1998). The complete AMS is programmed for installation on International Space Station in year 2003 for an operational period of 3 years. In this contribution we report on the experimental configuration of AMS that will be installed on International Space Station.

  6. A compact E × B filter: A multi-collector cycloidal focusing mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Blase, Ryan C., E-mail: rblase@swri.edu; Miller, Greg; Brockwell, Tim; Waite, J. Hunter [Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238 (United States); Westlake, Joseph [The Johns Hopkins University Applied Physics Laboratory LLC, 11100 Johns Hopkins Road, Laurel, Maryland 20723 (United States); Ostrom, Nathaniel; Ostrom, Peggy H. [Department of Integrative Biology, Michigan State University, 288 Farm Lane RM 203, East Lansing, Michigan 48824 (United States)

    2015-10-15

    A compact E × B mass spectrometer is presented. The mass spectrometer presented is termed a “perfect focus” mass spectrometer as the resolution of the device is independent of both the initial direction and energy of the ions (spatial and energy independent). The mass spectrometer is small in size (∼10.7 in.{sup 3}) and weight (∼2 kg), making it an attractive candidate for portability when using small, permanent magnets. A multi-collector Faraday cup design allows for the detection of multiple ion beams in discrete collectors simultaneously; providing the opportunity for isotope ratio monitoring. The mass resolution of the device is around 400 through narrow collector slits and the sensitivity of the device follows expected theoretical calculations of the ion current produced in the electron impact ion source. Example mass spectra obtained from the cycloidal focusing mass spectrometer are presented as well as information on mass discrimination based on instrumental parameters and isotope ratio monitoring of certain ion signals in separate Faraday cups.

  7. Two-arm electron/photon/hadron spectrometer TALES collaboration

    International Nuclear Information System (INIS)

    Hayano, R.S.; Sakurai, H.; Shigaki, K.

    1990-12-01

    To discover and probe the existence of a quark gluon plasma, it would seem desirable to have a detector which is sensitive to as many of the proposed 'signatures' as possible, so that they could all be observed and turned on and off in a predictable, reproducible, controllable and unified way. By emphasizing an open geometry experiment, optimized for detecting low-mass, low P T electron-positron pairs, a reasonably comprehensive measurement of the majority of the quark gluon plasma signatures must be obtained. Thus, the report first addresses physics motivation and goals, focusing on dielectron production; π 0 , η and direct photon measurements; global event characterization; identified hadron P T spectra; and charm production. An overview of the proposed central detector is then presented. Next, major detector components and expected performance are discussed, focusing on tracking, electron-pair reconstruction (a gas ring-imaging Cerenkov RICH counter), Dalitz-decay rejection, a highly-segmented electromagnetic calorimeter, global event characterization, an optical forward spectrometer, and a summary of performance. Finally, the report describes major research and development items and estimated costs. (N.K.)

  8. Electron-vibron coupling effects on electron transport via a single-molecule magnet

    Science.gov (United States)

    McCaskey, Alexander; Yamamoto, Yoh; Warnock, Michael; Burzurí, Enrique; van der Zant, Herre S. J.; Park, Kyungwha

    2015-03-01

    We investigate how the electron-vibron coupling influences electron transport via an anisotropic magnetic molecule, such as a single-molecule magnet (SMM) Fe4, by using a model Hamiltonian with parameter values obtained from density-functional theory (DFT). The magnetic anisotropy parameters, vibrational energies, and electron-vibron coupling strengths of the Fe4 are computed using DFT. A giant spin model is applied to the Fe4 with only two charge states, specifically a neutral state with a total spin S =5 and a singly charged state with S =9 /2 , which is consistent with our DFT result and experiments on Fe4 single-molecule transistors. In sequential electron tunneling, we find that the magnetic anisotropy gives rise to new features in the conductance peaks arising from vibrational excitations. In particular, the peak height shows a strong, unusual dependence on the direction as well as magnitude of applied B field. The magnetic anisotropy also introduces vibrational satellite peaks whose position and height are modified with the direction and magnitude of applied B field. Furthermore, when multiple vibrational modes with considerable electron-vibron coupling have energies close to one another, a low-bias current is suppressed, independently of gate voltage and applied B field, although that is not the case for a single mode with a similar electron-vibron coupling. In the former case, the conductance peaks reveal a stronger B -field dependence than in the latter case. The new features appear because the magnetic anisotropy barrier is of the same order of magnitude as the energies of vibrational modes with significant electron-vibron coupling. Our findings clearly show the interesting interplay between magnetic anisotropy and electron-vibron coupling in electron transport via the Fe4. Similar behavior can be observed in transport via other anisotropic magnetic molecules.

  9. The XRS microcalorimeter spectrometer at the Livermore Electron Beam Ion Trap

    Energy Technology Data Exchange (ETDEWEB)

    Porter, F S; Beiersdorfer, P; Boyce, K; Brown, G V; Chen, H; Gygax, J; Kahn, S M; Kelley, R; Kilbourne, C A; Magee, E; Thorn, D B

    2007-08-22

    NASA's X-ray Spectrometer (XRS) microcalorimeter instrument has been operating at the Electron Beam Ion Trap (EBIT) facility at Lawrence Livermore National Laboratory since July of 2000. The spectrometer is currently undergoing its third major upgrade to become an easy to use, extremely high performance instrument for a broad range of EBIT experiments. The spectrometer itself is broadband, capable of simultaneously operating from 0.1 to 12 keV and has been operated at up to 100 keV by manipulating its operating conditions. The spectral resolution closely follows the spaceflight version of the XRS, beginning at 10 eV FWHM at 6 keV in 2000, upgraded to 5.5 eV in 2003, and will hopefully be {approx}3.8 eV in the Fall of 2007. Here we review the operating principles of this unique instrument, the extraordinary science that has been performed at EBIT over the last 6 years, and prospects for future upgrades. Specifically we discuss upgrades to cover the high-energy band (to at least 100 keV) with a high quantum efficiency detector, and prospects for using a new superconducting detector to reach 0.8 eV resolution at 1 keV, and 2 eV at 6 keV with high counting rates.

  10. Design and construction of a high-stability, low-noise power supply for use with high-resolution electron energy loss spectrometers

    International Nuclear Information System (INIS)

    Katz, J.E.; Davies, P.W.; Crowell, J.E.; Somorjai, G.A.

    1982-01-01

    The design and construction of a high-stability, low-noise power supply which provides potentials for the lens and analyzer elements of a 127 0 Ehrhardt-type high-resolution electron energy loss spectrometer (HREELS) is described. The supply incorporates a filament emission-control circuit and facilities for measuring electron beam current at each spectrometer element, thus facilitating optimal tuning of the spectrometer. Spectra obtained using this supply are shown to have a four-fold improvement in signal-to-noise ratio and a higher resolution of the vibrational loss features when compared with spectra taken using a previously existing supply based on passive potential divider networks

  11. Electron-vibron coupling effects on electron transport via a single-molecule magnet

    NARCIS (Netherlands)

    McCaskey, A.; Yamamoto, Y.; Warnock, M.; Burzuri, E.; Van der Zant, H.S.J.; Park, K.

    2015-01-01

    We investigate how the electron-vibron coupling influences electron transport via an anisotropic magnetic molecule, such as a single-molecule magnet (SMM) Fe4, by using a model Hamiltonian with parameter values obtained from density-functional theory (DFT). The magnetic anisotropy parameters,

  12. Micro Plasma Spectrometer

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this IRAD project is to develop a preliminary design elements of miniature electron and ion plasma spectrometers and supporting electronics, focusing...

  13. Study of energetic electrons in the outer radiation-belt regions using data obtained by the LLL spectrometer on OGO-5 in 1968

    International Nuclear Information System (INIS)

    West, H.I. Jr.; Buck, R.M.; Davidson, G.

    1979-01-01

    An account is given of measurements of electrons made by the LLL magnetic electron spectrometer (60 to 3000 keV in seven differential energy channels) on the Ogo-5 satellite in the earth's outer-belt regions during 1968 and early 1969. The data were analyzed specifically to determine pitch-angle diffusion lifetimes as a function of energy in the L-range 2 to 5. As a part of this effort, the general dynamics of these regions were studied in terms of the time-dependent energy spectra, and pitch-angle distributions for the seven energy groups were obtained as a function of L with representative values presented for L = 2.5 to 6. The pitch-angle-diffusion results were used to analyze the dynamics of the electrons injected following the intense storms on October 31 and November 1, 1968, in terms of radial diffusion; the derived diffusion coefficients provide a quite reasonable picture of electron transport in the radiation belts. Both the radial- and pitch-angle-diffusion results are compared with earlier results. 53 references

  14. The barrel muon spectrometer of the ATLAS detector has acquired its first cosmic event in a magnetic field produced by the barrel toroid magnet.

    CERN Multimedia

    2006-01-01

    A 3-D event display of a cosmic muon event, showing the path of a muon travelling through three layers of the barrel muon spectrometer. Three of the eight coils of the barrel toroid magnet can be seen in the top half of the drawing.

  15. Magnetic electron scattering

    International Nuclear Information System (INIS)

    Peterson, G.A.

    1989-01-01

    We briefly review some of the motivations, early results, and techniques of magnetic elastic and inelastic electron-nucleus scattering. We then discuss recent results, especially those acquired at high momentum transfers. 50 refs., 19 figs

  16. Two-lens spectrometer for. beta. polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Holdsworth, D; Paul, D [Toronto Univ., Ontario (Canada). Dept. of Physics

    1984-06-01

    A test spectrometer has been built having four degrees of freedom which have been varied to optimize the transmission in a configuration in which the image distance is large compared to the object distance. Iron-clad magnets of 15 cm effective inside diameter were used. Within the limits of the primary magnet field, the optimized transmission T (%. of 4..pi.. sr) increases as the source is advanced through the magnet towards the polarimeter, approximately as T=5.1 exp(zsub(s)/10.5), where zsub(s) is in cm, measured from the position of peak axial field. When the source-image distance is 1.8 m the optimum separation of the peak axial fields of the magnets is 67+-1 cm and the spectrometer transmission is the same for parallel or antiparallel fields. When operating in the optimum configuration, the spectrometer accepts particles with initial trajectories from 18/sup 0/ to 42/sup 0/ relative to the axis and delivers them at the target with half-angle of convergence less than 4.1/sup 0/.

  17. The SeaQuest Spectrometer at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Aidala, C.A.; et al.

    2017-06-29

    The SeaQuest spectrometer at Fermilab was designed to detect oppositely-charged pairs of muons (dimuons) produced by interactions between a 120 GeV proton beam and liquid hydrogen, liquid deuterium and solid nuclear targets. The primary physics program uses the Drell-Yan process to probe antiquark distributions in the target nucleon. The spectrometer consists of a target system, two dipole magnets and four detector stations. The upstream magnet is a closed-aperture solid iron magnet which also serves as the beam dump, while the second magnet is an open aperture magnet. Each of the detector stations consists of scintillator hodoscopes and a high-resolution tracking device. The FPGA-based trigger compares the hodoscope signals to a set of pre-programmed roads to determine if the event contains oppositely-signed, high-mass muon pairs.

  18. The high-acceptance dielectron spectrometer HADES

    International Nuclear Information System (INIS)

    Agakichiev, G.; Destefanis, M.; Gilardi, C.; Kirschner, D.; Kuehn, W.; Lange, J.S.; Lehnert, J.; Lichtblau, C.; Lins, E.; Metag, V.; Mishra, D.; Novotny, R.; Pechenov, V.; Pechenova, O.; Perez Cavalcanti, T.; Petri, M.; Ritman, J.; Salz, C.; Schaefer, D.; Skoda, M.; Spataro, S.; Spruck, B.; Toia, A.; Agodi, C.; Coniglione, R.; Cosentino, L.; Finocchiaro, P.; Maiolino, C.; Piattelli, P.; Sapienza, P.; Vassiliev, D.; Alvarez-Pol, H.; Belver, D.; Cabanelas, P.; Castro, E.; Duran, I.; Fernandez, C.; Fuentes, B.; Garzon, J.A.; Kurtukian-Nieto, T.; Rodriguez-Prieto, G.; Sabin-Fernandez, J.; Sanchez, M.; Vazquez, A.; Atkin, E.; Volkov, Y.; Badura, E.; Bertini, D.; Bielcik, J.; Bokemeyer, H.; Dahlinger, M.; Daues, H.W.; Galatyuk, T.; Garabatos, C.; Gonzalez-Diaz, D.; Hehner, J.; Heinz, T.; Hoffmann, J.; Holzmann, R.; Koenig, I.; Koenig, W.; Kolb, B.W.; Kopf, U.; Lang, S.; Leinberger, U.; Magestro, D.; Muench, M.; Niebur, W.; Ott, W.; Pietraszko, J.; Rustamov, A.; Schicker, R.M.; Schoen, H.; Schoen, W.; Schroeder, C.; Schwab, E.; Senger, P.; Simon, R.S.; Stelzer, H.; Traxler, M.; Yurevich, S.; Zovinec, D.; Zumbruch, P.; Balanda, A.; Kozuch, A.; Przygoda, W.; Bassi, A.; Bassini, R.; Boiano, C.; Bartolotti, A.; Brambilla, S.; Bellia, G.; Migneco, E.; Belyaev, A.V.; Chepurnov, V.; Chernenko, S.; Fateev, O.V.; Ierusalimov, A.P.; Smykov, L.; Troyan, A.Yu.; Zanevsky, Y.V.; Benovic, M.; Hlavac, S.; Turzo, I.; Boehmer, M.; Christ, T.; Eberl, T.; Fabbietti, L.; Friese, J.; Gernhaeuser, R.; Gilg, H.; Homolka, J.; Jurkovic, M.; Kastenmueller, A.; Kienle, P.; Koerner, H.J.; Kruecken, R.; Maier, L.; Maier-Komor, P.; Sailer, B.; Schroeder, S.; Ulrich, A.; Wallner, C.; Weber, M.; Wieser, J.; Winkler, S.; Zeitelhack, K.; Boyard, J.L.; Genolini, B.; Hennino, T.; Jourdain, J.C.; Moriniere, E.; Pouthas, J.; Ramstein, B.; Rosier, P.; Roy-Stephan, M.; Sudol, M.; Braun-Munzinger, P.; Diaz, J.; Dohrmann, F.; Dressler, R.; Enghardt, W.; Heidel, K.; Hutsch, J.; Kanaki, K.; Kotte, R.; Naumann, L.; Sobiella, M.; Wuestenfeld, J.; Zhou, P.; Dybczak, A.; Jaskula, M.; Kajetanowicz, M.; Kidon, L.; Korcyl, K.; Kulessa, R.; Malarz, A.; Michalska, B.; Otwinowski, J.; Ploskon, M.; Prokopowicz, W.; Salabura, P.; Szczybura, M.; Trebacz, R.; Walus, W.; Wisniowski, M.; Wojcik, T.; Froehlich, I.; Lippmann, C.; Lorenz, M.; Markert, J.; Michel, J.; Muentz, C.; Pachmayer, Y.C.; Rosenkranz, K.; Stroebele, H.; Sturm, C.; Tarantola, A.; Teilab, K.; Wang, Y.; Zentek, A.; Golubeva, M.; Guber, F.; Ivashkin, A.; Karavicheva, T.; Kurepin, A.; Lapidus, K.; Reshetin, A.; Sadovsky, A.; Shileev, K.; Tiflov, V.; Grosse, E.; Kaempfer, B.; Iori, I.; Krizek, F.; Kugler, A.; Marek, T.; Novotny, J.; Pleskac, R.; Pospisil, V.; Sobolev, Yu.G.; Suk, M.; Taranenko, A.; Tikhonov, A.; Tlusty, P.; Wagner, V.; Mousa, J.; Parpottas, Y.; Tsertos, H.; Nekhaev, A.; Smolyankin, V.; Palka, M.; Roche, G.; Schmah, A.; Stroth, J.

    2009-01-01

    HADES is a versatile magnetic spectrometer aimed at studying dielectron production in pion, proton and heavy-ion-induced collisions. Its main features include a ring imaging gas Cherenkov detector for electron-hadron discrimination, a tracking system consisting of a set of 6 superconducting coils producing a toroidal field and drift chambers and a multiplicity and electron trigger array for additional electron-hadron discrimination and event characterization. A two-stage trigger system enhances events containing electrons. The physics program is focused on the investigation of hadron properties in nuclei and in the hot and dense hadronic matter. The detector system is characterized by an 85% azimuthal coverage over a polar angle interval from 18 to 85 , a single electron efficiency of 50% and a vector meson mass resolution of 2.5%. Identification of pions, kaons and protons is achieved combining time-of-flight and energy loss measurements over a large momentum range (0.1< p< 1.0 GeV/c). This paper describes the main features and the performance of the detector system. (orig.)

  19. The magnetized electron-acoustic instability driven by a warm, field-aligned electron beam

    International Nuclear Information System (INIS)

    Sooklal, A.; Mace, R.L.

    2004-01-01

    The electron-acoustic instability in a magnetized plasma having three electron components, one of which is a field-aligned beam of intermediate temperature, is investigated. When the plasma frequency of the cool electrons exceeds the electron gyrofrequency, the electron-acoustic instability 'bifurcates' at sufficiently large propagation angles with respect to the magnetic field to yield an obliquely propagating, low-frequency electron-acoustic instability and a higher frequency cyclotron-sound instability. Each of these instabilities retains certain wave features of its progenitor, the quasiparallel electron-acoustic instability, but displays also new magnetic qualities through its dependence on the electron gyrofrequency. The obliquely propagating electron-acoustic instability requires a lower threshold beam speed for its excitation than does the cyclotron-sound instability, and for low to intermediate beam speeds has the higher maximum growth rate. When the plasma is sufficiently strongly magnetized that the plasma frequency of the cool electrons is less than the electron gyrofrequency, the only instability in the electron-acoustic frequency range is the strongly magnetized electron-acoustic instability. Its growth rate and real frequency exhibit a monotonic decrease with wave propagation angle and it grows at small to intermediate wave numbers where its parallel phase speed is approximately constant. The relevance of the results to the interpretation of cusp auroral hiss and auroral broadband electrostatic noise is briefly discussed

  20. Electron holography of Fe-based nanocrystalline magnetic materials (invited)

    International Nuclear Information System (INIS)

    Shindo, Daisuke; Park, Young-Gil; Gao, Youhui; Park, Hyun Soon

    2004-01-01

    Magnetic domain structures of nanocrystalline magnetic materials were extensively investigated by electron holography with a change in temperature or magnetic field applied. In both soft and hard magnetic materials, the distribution of lines of magnetic flux clarified in situ by electron holography was found to correspond well to their magnetic properties. An attempt to produce a strong magnetic field using a sharp needle made of a permanent magnet, whose movement is controlled by piezo drives has been presented. This article demonstrates that the attempt is promising to investigate the magnetization process of hard magnetic materials by electron holography

  1. Spin fluctuation theory of itinerant electron magnetism

    CERN Document Server

    Takahashi, Yoshinori

    2013-01-01

    This volume shows how collective magnetic excitations determine most of  the magnetic properties of itinerant electron magnets. Previous theories were mainly restricted to the Curie-Weiss law temperature dependence of magnetic susceptibilities. Based on the spin amplitude conservation idea including the zero-point fluctuation amplitude, this book shows that the entire temperature and magnetic field dependence of magnetization curves, even in the ground state, is determined by the effect of spin fluctuations. It also shows that the theoretical consequences are largely in agreement with many experimental observations. The readers will therefore gain a new comprehensive perspective of their unified understanding of itinerant electron magnetism.

  2. Hafnium Films and Magnetic Shielding for TIME, A mm-Wavelength Spectrometer Array

    Science.gov (United States)

    Hunacek, J.; Bock, J.; Bradford, C. M.; Butler, V.; Chang, T.-C.; Cheng, Y.-T.; Cooray, A.; Crites, A.; Frez, C.; Hailey-Dunsheath, S.; Hoscheit, B.; Kim, D. W.; Li, C.-T.; Marrone, D.; Moncelsi, L.; Shirokoff, E.; Steinbach, B.; Sun, G.; Trumper, I.; Turner, A.; Uzgil, B.; Weber, A.; Zemcov, M.

    2018-04-01

    TIME is a mm-wavelength grating spectrometer array that will map fluctuations of the 157.7-μm emission line of singly ionized carbon ([CII]) during the epoch of reionization (redshift z ˜ 5-9). Sixty transition-edge sensor (TES) bolometers populate the output arc of each of the 32 spectrometers, for a total of 1920 detectors. Each bolometer consists of gold absorber on a ˜ 3 × 3 mm silicon nitride micro-mesh suspended near the corners by 1 × 1 × 500 μm silicon nitride legs targeting a photon-noise-dominated NEP ˜ 1 × 10^{-17} W/√{Hz} . Hafnium films are explored as a lower-T_c alternative to Ti (500 mK) for TIME TESs, allowing thicker support legs for improved yield. Hf T_c is shown to vary between 250 and 450 mK when varying the resident Ar pressure during deposition. Magnetic shielding designs and simulations are presented for the TIME first-stage SQUIDs. Total axial field suppression is predicted to be 5 × 10^7.

  3. The MEG positron spectrometer

    International Nuclear Information System (INIS)

    Nishiguchi, Hajime

    2007-01-01

    We have been developing an innovative spectrometer for the MEG experiment at the Paul Scherrer Institute (PSI) in Switzerland. This experiment searches for a lepton flavour violating decay μ + →e + γ with a sensitivity of 10 -13 in order to explore the region predicted by supersymmetric extensions of the standard model. The MEG positron spectrometer consists of a specially designed superconducting solenoidal magnet with a highly graded field, an ultimate low-mass drift chamber system, and a precise time measuring counter system. This innovative positron spectrometer is described here focusing on the drift chamber system

  4. Experience in automatic processing of 340.000 images from ITEF 3-m magnetic spectrometer

    International Nuclear Information System (INIS)

    Dzhelyadin, R.I.; Dukhovskoj, I.A.; Ivanov, L.V.; Kishkurno, V.V.; Krutenkova, A.P.; Kulikov, V.V.; Lyulevich, V.I.; Polikarpov, V.M.; Radkevich, I.A.; Fedorets, V.S.; Fedotov, O.P.

    1974-01-01

    A number of conclusions were made regarding automatic processing of 340.000 pictures (1.020.000 frames) developed on a three-meter magnetic spectrometer with spark chambers. Possibilities for time optimization of automatic processing programs are discussed. The results of processing of a series of photographs were analysed to compare the paramters of automatic ans semi-automatic processing. Some problems relating to organization and technology of picture processing are also autlined [ru

  5. The design of the Spectrometer Ring at the HIAF

    Science.gov (United States)

    Wu, B.; Yang, J. C.; Xia, J. W.; Yan, X. L.; Hu, X. J.; Mao, L. J.; Sheng, L. N.; Wu, J. X.; Yin, D. Y.; Chai, W. P.; Shen, G. D.; Ge, W. W.; Wang, G.; Zhao, H.; Ruan, S.; Ma, X. W.; Wang, M.; Litvinov, S.; Wen, W. Q.; Chen, X. C.; Chen, R. J.; Tang, M. T.; Wu, W.; Luo, C.; Zhao, T. C.; Shi, C. F.; Fu, X.; Liu, J.; Liang, L.

    2018-02-01

    The Spectrometer Ring (SRing) is an essential part of the High Intensity heavy-ion Accelerator Facility project (HIAF) in China. It is designed as a multi-functional experimental storage ring, which will be able to operate in three ion optical operation modes. The SRing will be used as a time-of-flight mass spectrometer for short-lived, especially neutron-rich nuclei. It will also be used to collect and cool Rare Isotope Beams (RIBs) or highly-charged stable ion beams for nuclear and atomic physics experiments. The design magnetic rigidity is in the range 1.5 to 15 Tm. The beam cooling system consists of stochastic cooling and electron cooling devices. With a help of an electron cooler, stored ions will be decelerated to a minimum energy of 30 MeV/u by RF cavities. The extraction system of the SRing will allow cooled ion beams to be extracted to an external target for further ion manipulations or reaction experiments. The general ion optics design and technical requirements of SRing subsystems are presented and discussed in this paper.

  6. Electron-nuclear magnetic resonance in the inverted state

    International Nuclear Information System (INIS)

    Ignatchenko, V.A.; Tsifrinovich, V.I.

    1975-01-01

    The paper considers the susceptibility of the electron-nucleus system of a ferromagnet when nuclear magnetization is inverted with respect to the hyperfine field direction. The inverted state is a situation in which nuclear magnetization is turned through π relative to its equilibrium orientation, whereas electron magnetization is in an equilibrium state with respect to an external magnetic field. The consideration is carried out for a thin plate magnetized in its plane. Amplification of a weak radiofrequency signal can be attained under the fulfilment of an additional inequality relating the interaction frequency with electron and nuclear relaxation parameters. The gain may exceed the gain for an inverted nuclear system in magnetically disordered substances. In the range of strong interaction between the frequencies of ferromagnetic (FMR) and nuclear magnetic (NMR) resonances the electron-nuclear magnetic resonance (ENMR) spectrum possesses a fine structure which is inverse to that obtained for the ENMR spectrum in a normal state. The inverted state ENMR line shape is analysed in detail for the case of so weak HF fields that the relaxation conditions may be regarded as stationary. The initial (linear) stages of a forced transient process arising in an electron-nuclear system under the effect of a strong HF field are briefly analysed

  7. Integrating magnetism into semiconductor electronics

    Energy Technology Data Exchange (ETDEWEB)

    Zakharchenya, Boris P; Korenev, Vladimir L [A.F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg (Russian Federation)

    2005-06-30

    The view of a ferromagnetic-semiconducting hybrid structure as a single tunable system is presented. Based on an analysis of existing experiments it is shown that, contrary to a 'common sense', a nonmagnetic semiconductor is capable of playing an important role in controlling ferromagnetism. Magnetic properties of a hybrid (the hysteresis loop and the spatial orientation of magnetization) can be tuned both optically and electrically by utilizing semiconductor-making the hybrid an electronic-write-in and electronic-read-out elementary storage unit. (methodological notes)

  8. Integrating magnetism into semiconductor electronics

    International Nuclear Information System (INIS)

    Zakharchenya, Boris P; Korenev, Vladimir L

    2005-01-01

    The view of a ferromagnetic-semiconducting hybrid structure as a single tunable system is presented. Based on an analysis of existing experiments it is shown that, contrary to a 'common sense', a nonmagnetic semiconductor is capable of playing an important role in controlling ferromagnetism. Magnetic properties of a hybrid (the hysteresis loop and the spatial orientation of magnetization) can be tuned both optically and electrically by utilizing semiconductor-making the hybrid an electronic-write-in and electronic-read-out elementary storage unit. (methodological notes)

  9. Studies on reducing the scale of a double focusing mass spectrometer

    International Nuclear Information System (INIS)

    Chambers, D.M.; Gregg, H.R.; Andresen, B.D.

    1993-05-01

    Several groups have developed miniaturized sector mass spectrometers with the goal of remote sensing in confined spaces or portability. However, these achievements have been overshadowed by more successful development of man-portable quadrupole and ion trap mass spectrometers. Despite these accomplishments the development of a reduced-scale sector mass spectrometer remains attractive as a potentially low-cost, robust instrument requiring very simple electronics and low power. Previous studies on miniaturizing sector instruments include the use of a Mattauch-Herzog design for a portable mass spectrograph weighing less than 10 kg. Other work has included the use of a Nier-Johnson design in spacecraft-mountable gas chromatography mass spectrometers for the Viking spacecraft as well as miniature sector-based MS/MS instrument. Although theory for designing an optimized system with high resolution and mass accuracy is well understood, such specifications have not yet been achieved in a miniaturized instrument. To proceed further toward the development of a miniaturized sector mass spectrometer, experiments were conducted to understand and optimize a practical, yet nonideal instrument configuration. The sector mass spectrometer studied in this work is similar to the ones developed for the Viking project, but was further modified to be low cost, simple and robust. Characteristics of this instrument that highlight its simplicity include the use of a modified Varian leak detector ion source, source ion optics that use one extraction voltage, and an unshunted fixed nonhomogeneous magnetic sector. The effects of these design simplifications on ion trajectory were studied by manipulating the ion beam along with the magnetic sector position. This latter feature served as an aid to study ion focusing amidst fringing fields as well as nonhomogeneous forces and permitted empirical realignment of the instrument

  10. Electronics for processing of data from a double collector isotopic ratio mass spectrometer

    International Nuclear Information System (INIS)

    Handu, V.K.

    1979-01-01

    The output data available from the mass spectrometer type MS-660 developed in the mass spectrometry section of Technical Physics Division of the Bhabha Atomic Research Centre, Bombay, for the determination of H/D ratios in liquid/gas sample consist of uncompensated mass 3 and mass 2 signals. After the mass 3 signal has been compensated for H 3 + formation, the on-line ratio of compensated mass 3 to mass 2 is calculated, displayed, and then printed on a printer for record. The electronic compensation circuit, the discrete voltage-to-frequency (V/F) converter circuit, the ratio calculating system using V/F converters, and a digital interface system for Hindustan Teleprinter to print out the ratios are explained. Results obtained on mass spectrometer MS-660 are presented. (auth.)

  11. Spectrometer magnet for experiment NA4 (deep inelastic muon scattering)

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    This is one section of the toroidal-field spectrometer magnet of experiment NA4 (deep inelastic muon scattering), shown here during the installation period and later located in the North Area of the SPS. To see all 4 sections, select 7709201. Igor Savin from Dubna looks at what his lab had provided: the huge iron disks were machined at and provided by Dubna. Multi-Wire Proportional Chambers were installed in the gaps between the packs of 4 disks. When the beam from the SPS struck the target (to the right in this picture), the iron would quickly stop the hadronic shower, whilst the muons would go on, performing oscillations in the toroidal field. NA4 was a CERN-Dubna-Munich-Saclay (later also Bologna) collaboration, spokesman: Carlo Rubbia.

  12. Electron interactions with nuclei. Progress report

    International Nuclear Information System (INIS)

    1986-07-01

    Research includes work at SLAC, Bates, and Saclay research facilities. The high energy program at SLAC concerns inclusive electron scattering from nuclei, electroexcitation of the delta in nuclei, and the design of an electron detection system for the SLAC 1.6 GeV/c magnetic spectrometer. The high energy program at Bates includes quasielastic electron scattering from 1 H, 2 H, 3 He, and 4 He, and electron scattering from 3 H and 3 He. Nuclear structure studies are based on high resolution inelastic electron scattering and include electron scattering from 208 Pb and mercury isotopes, charge densities from low lying states in 86 Sr, and magnetization densities of 205 Tl and 207 Pb. (DWL) 72 refs., 29 figs., 1 tab

  13. Fabrication, Testing and Modeling of the MICE Superconducting Spectrometer Solenoids

    International Nuclear Information System (INIS)

    Virostek, S.P.; Green, M.A.; Trillaud, F.; Zisman, M.S.

    2010-01-01

    The Muon Ionization Cooling Experiment (MICE), an international collaboration sited at Rutherford Appleton Laboratory in the UK, will demonstrate ionization cooling in a section of realistic cooling channel using a muon beam. A five-coil superconducting spectrometer solenoid magnet will provide a 4 tesla uniform field region at each end of the cooling channel. Scintillating fiber trackers within the 400 mm diameter magnet bore tubes measure the emittance of the beam as it enters and exits the cooling channel. Each of the identical 3-meter long magnets incorporates a three-coil spectrometer magnet section and a two-coil section to match the solenoid uniform field into the other magnets of the MICE cooling channel. The cold mass, radiation shield and leads are currently kept cold by means of three two-stage cryocoolers and one single-stage cryocooler. Liquid helium within the cold mass is maintained by means of a re-condensation technique. After incorporating several design changes to improve the magnet cooling and reliability, the fabrication and acceptance testing of the spectrometer solenoids have proceeded. The key features of the spectrometer solenoid magnets, the development of a thermal model, the results of the recently completed tests, and the current status of the project are presented.

  14. Design of electron beam bending magnet system using three sector magnets for electron and photon therapy: a simulation approach

    International Nuclear Information System (INIS)

    Shahzad, A.A.; Bhoraskar, V.N.; Dhole, S.D.

    2013-01-01

    The 270 degree doubly achromatic beam bending magnet system using three sector magnets has been designed mainly for treating cancer and skin diseases. The main requirements of the design of three magnet system is to focus an electron beam having a spot size less than 3mm x 3mm, energy spread within 3% and divergence angle ≤ 3 mrad at the target. To achieve these parameters the simulation was carried out using Lorentz-3EM software. The beam spot, divergence angle and energy spread were observed with respect to the variation in angles of sector magnets and drift distances. From the simulated results, it has been optimized that all the three sector magnets has an angle of 62 degree and the drift distance 68 mm. It is also observed that at the 1637, 2425, 3278, 4165 and 5690 Amp-turn, the optimized design produces 3851, 5754, 7434, 9356 and 11425 Gauss of magnetic field at median plane require to bend 6, 9, 12, 15 and 18 MeV energy of electron respectively for electron therapy. The output parameters of the optimized design are energy spread 3%, divergence angle ∼ 3 mrad and spot size 2.8 mm. Moreover, for 6 MV and 15 MV photon therapy application, an electron beam of energy 6.5 MeV and 15.5 MeV extracted from magnet system and focussed on the Bremsstrahlung target. For the photon therapy the 1780, and 4456 amp-turn, an optimized design produces 4148 and 9682 Gauss of magnetic field at median plane require to bend 6.5 and 15.5 MeV energy of electron respectively, which further produces Bremsstrahlung in Tungsten target. (author)

  15. Simulation of the SAGE spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Cox, D.M.; Herzberg, R.D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Konki, J.; Greenlees, P.T.; Pakarinen, J.; Papadakis, P.; Rahkila, P.; Sandzelius, M.; Sorri, J. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Hauschild, K. [Universite Paris-Sud, CSNSM-IN2P3-CNRS, Orsay (France)

    2015-06-15

    The SAGE spectrometer combines a Ge-detector array with a Si detector to allow simultaneous detection of γ-rays and electrons. A comprehensive GEANT4 simulation package of the SAGE spectrometer has been developed with the ability to simulate the expected datasets based on user input files. The measured performance of the spectrometer is compared to the results obtained from the simulations. (orig.)

  16. Simulation of the SAGE spectrometer

    International Nuclear Information System (INIS)

    Cox, D.M.; Herzberg, R.D.; Konki, J.; Greenlees, P.T.; Pakarinen, J.; Papadakis, P.; Rahkila, P.; Sandzelius, M.; Sorri, J.; Hauschild, K.

    2015-01-01

    The SAGE spectrometer combines a Ge-detector array with a Si detector to allow simultaneous detection of γ-rays and electrons. A comprehensive GEANT4 simulation package of the SAGE spectrometer has been developed with the ability to simulate the expected datasets based on user input files. The measured performance of the spectrometer is compared to the results obtained from the simulations. (orig.)

  17. 'aspect' - a new spectrometer for the measurement of the angular correlation coefficient a in neutron beta decay

    CERN Document Server

    Zimmer, O; Grinten, M G D; Heil, W; Glück, F

    2000-01-01

    The combination of the coefficient a of the antineutrino/electron angular correlation with the beta asymmetry of the neutron provides a sensitive test for scalar and tensor contributions to the electroweak Lagrangian, as well as for right-handed currents. A method is given for measuring a with high sensitivity from the proton recoil spectrum. The method is based on a magnetic spectrometer with electrostatic retardation potentials such as used for searches of the neutrino mass in tritium beta decay. The spectrometer can also be used for similar studies using radioactive nuclei.

  18. Transport of runaway and thermal electrons due to magnetic microturbulence

    International Nuclear Information System (INIS)

    Mynick, H.E.; Strachan, J.D.

    1981-01-01

    The ratio of the runaway electron confinement to thermal electron energy confinement is derived for tokamaks where both processes are determined by free streaming along stochastic magnetic field lines. The runaway electron confinement is enhanced at high runaway electron energies due to phase averaging over the magnetic perturbations when the runaway electron drift surfaces are displaced from the magnetic surfaces. Comparison with experimental data from LT-3, Ormak, PLT, ST, and TM-3 indicates that magnetic stochasticity may explain the relative transport rates of runaways and thermal electron energy

  19. Recent ion optics and mass spectrometers

    International Nuclear Information System (INIS)

    Matsuda, Hisashi

    1976-01-01

    The establishment of the third order approximation method for computing the orbit of the ion optical system for mass spectrometers and the completion of its computer program are reported. A feature of this orbit computation is in that the effect of the fringing field can be considered with the accuracy of third order approximation. Several new ion optical systems for mass spectrometers have been proposed by using such orbit computing programs. Brief explanation and the description on the future prospect and problems are made on the following items: the vertual image double focusing mass spectrometer, the second order double focusing mass spectrometer, the E x B superposed field mass spectrometer, and the apparatus with a cylindrical electric field and Q-lens. In the E x B superposed field with Matsuda plates, if the magnetic field is generated by an electromagnet instead of a permanent magnet, the dispersion of mass and energy can be changed at will. The Matsuda plates are known as the auxiliary electrodes positioned at the top and bottom of a cylindrical capacitor. Utilizing those characteristics, a zoom spectrometer can be made, with which only a necessary part of mass spectra can be investigated in detail, but the whole spectra are investigated roughly. In addition, the distribution of energy can be investigated simultaneously after the separation of ionic mass similarly to the parabola apparatus. (Iwakiri, K.)

  20. A novel approach to electron data background treatment in an online wide-angle spectrometer for laser-accelerated ion and electron bunches

    Science.gov (United States)

    Lindner, F. H.; Bin, J. H.; Englbrecht, F.; Haffa, D.; Bolton, P. R.; Gao, Y.; Hartmann, J.; Hilz, P.; Kreuzer, C.; Ostermayr, T. M.; Rösch, T. F.; Speicher, M.; Parodi, K.; Thirolf, P. G.; Schreiber, J.

    2018-01-01

    Laser-based ion acceleration is driven by electrical fields emerging when target electrons absorb laser energy and consecutively leave the target material. A direct correlation between these electrons and the accelerated ions is thus to be expected and predicted by theoretical models. We report on a modified wide-angle spectrometer, allowing the simultaneous characterization of angularly resolved energy distributions of both ions and electrons. Equipped with online pixel detectors, the RadEye1 detectors, the investigation of this correlation gets attainable on a single shot basis. In addition to first insights, we present a novel approach for reliably extracting the primary electron energy distribution from the interfering secondary radiation background. This proves vitally important for quantitative extraction of average electron energies (temperatures) and emitted total charge.

  1. Trapping of Electron Cloud LLC/Cesrta Quadrupole and Sextupole Magnets

    International Nuclear Information System (INIS)

    Wang, L.

    2011-01-01

    The Cornell Electron Storage Ring (CESR) has been reconfigured as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R and D (1). One of the primary goals of the CesrTA program is to investigate the interaction of the electron cloud with low emittance positron beam to explore methods to suppress the electron cloud, develop suitable advanced instrumentation required for these experimental studies and benchmark predictions by simulation codes. This paper reports the simulation of the electron-cloud formation in CESRTA and ILC quadrupole and sextupole magnets using the 3D code CLOUDLAND. We found that electrons can be trapped with a long lifetime in a quadrupole and sextupole magnet due to the mirror field trapping mechanism. We study the effects of magnet strength, bunch current, ante-chamber effect, bunch spacing effect and secondary emission yield (SEY) in great detail. The development of an electron cloud in magnets is the main concern where a weak solenoid field is not effective. Quadrupole and sextupole magnets have mirror field configurations which may trap electrons by the mirror field trapping mechanism (2). Fig.1 shows the orbit of a trapped electron in a quadrupole magnet. The electron makes gyration motion (called transverse motion) and also moves along the field line (called longitudinal motion). At the mirror point (middle of the field line), there is a maximum longitudinal energy and minimum transverse energy. When the electron moves away from the mirror point, its longitudinal energy reduces and the transverse energy increases as the magnetic field increases. If the magnetic field is strong enough, the longitudinal energy becomes zero at one point and then the electron is turned back by the strong field. Note that the electrons are trapped in the region near the middle of the field lines. Although all quadrupole and sextupole magnets can trap electrons in principle, the

  2. Nonlinear magnetic electron tripolar vortices in streaming plasmas.

    Science.gov (United States)

    Vranjes, J; Marić, G; Shukla, P K

    2000-06-01

    Magnetic electron modes in nonuniform magnetized and unmagnetized streaming plasmas, with characteristic frequencies between the ion and electron plasma frequencies and at spatial scales of the order of the collisionless skin depth, are studied. Two coupled equations, for the perturbed (in the case of magnetized plasma) or self-generated (for the unmagnetized plasma case) magnetic field, and the temperature, are solved in the strongly nonlinear regime and stationary traveling solutions in the form of tripolar vortices are found.

  3. Superconductivity and the magnetic electron bond

    International Nuclear Information System (INIS)

    Szurek, P.

    1989-01-01

    The concept of the magnetic electron bond as the fundamental characteristic of superconductivity was first introduced during a presentation at the 1988 Winter Annual Meeting of the American Society of Mechanical Engineers. Postulates describing the role of the electron and the magnetic bond were suggested to explain in a consistent manner known observations. What may becoming clear is that a boundary set of conditions may exist above and below the transition temperature at which a material superconducts. Prior to recent history, scientists have concentrated on postulating, experimenting, and learning about the set of conditions that exist above the transition temperature, which has set the standard for todays quantum theory. Above the transition temperature they have learned about the interrelationships that exist between the electron, a small magnetic and negatively charged body, and the nucleus, a large positively charged body. By grouping common general characteristics due to the interaction between the outer shell electrons and the nucleus of different elements, three bond types have been established, covalent, ionic, and metallic. They may now be in the process of determining those conditions that lie below the transition temperature, a realm where charge effects may no longer dominate magnetic effects. This may involve updating the quantum theory to reflect those conditions that exist above and below the transition temperature. The following discussion reviews, updates, and attempts to answer some preliminary questions regarding postulates that may define some of the conditions that lie below the transition temperature. As an introduction, figure 1 depicts what may occur to loosely held outer shell electrons below the transition temperature due to increased inner electron shielding. 7 refs., 9 figs

  4. Simultaneous ion detection in a mass spectrometer with variable mass dispersion

    International Nuclear Information System (INIS)

    Tuithof, H.H.

    1977-01-01

    This thesis mainly describes the ion-optics of a magnetic mass spectrometer system, especially applied to the projection of a significant part of the mass spectrum onto a flat ion-detector. The complete detector consists of a channeltron electron multiplier array with phosphor screen and a Vidicon-multichannel analyzer combination for simultaneous read-out. In order to optimise the spectral range projected onto the channelplate, by varying the mass dispersion and to rotate the oblique angle of the mass focal plane with respect to the detector surface, the sector magnet has been combined with electrostatic and magnetic quadrupole lenses. This detector will find wide application in the analysis of minute sample quantities, in the recording of extremely short ion events (large molecules) and at collision activation mass-spectrometry studies

  5. Program controlled system for measuring and monitoring the electron coherent radiation spectrum of Yerevan synchrotron

    International Nuclear Information System (INIS)

    Adamyan, F.V.; Vartapetyan, G.A.; Galumyan, P.I.

    1980-01-01

    An automatic system for measurement, processing and control of energy spectrum of polarized photons realized at the Yerevan electron synchrotron is described. For measuring energy spectra of intensive high energy photon beams a pair spectrometer is used which comprises an aluminium target-converter, an analizing magnet and 2 telescopes of scintillation counters for electron-positron pairs registration. the procedure of spectra measurement by the pair spectrometer is reduced to determining the converted e + e - pairs yield at certain values of the H field intensity of the analizing magnet. An algorithm of the data express-processing for operative monitoring of peak energy stability of electron coherent radiation spectrum is given. The spectra measurement results obtained under real experimental conditions are presented

  6. Electron-assisted magnetization tunneling in single spin systems

    Science.gov (United States)

    Balashov, Timofey; Karlewski, Christian; Märkl, Tobias; Schön, Gerd; Wulfhekel, Wulf

    2018-01-01

    Magnetic excitations of single atoms on surfaces have been widely studied experimentally in the past decade. Lately, systems with unprecedented magnetic stability started to emerge. Here, we present a general theoretical investigation of the stability of rare-earth magnetic atoms exposed to crystal or ligand fields of various symmetry and to exchange scattering with an electron bath. By analyzing the properties of the atomic wave function, we show that certain combinations of symmetry and total angular momentum are inherently stable against first or even higher-order interactions with electrons. Further, we investigate the effect of an external magnetic field on the magnetic stability.

  7. Electron-electron interactions in graphene field-induced quantum dots in a high magnetic field

    DEFF Research Database (Denmark)

    Orlof, A.; Shylau, Artsem; Zozoulenko, I. V.

    2015-01-01

    We study the effect of electron-electron interaction in graphene quantum dots defined by an external electrostatic potential and a high magnetic field. To account for the electron-electron interaction, we use the Thomas-Fermi approximation and find that electron screening causes the formation...... of compressible strips in the potential profile and the electron density. We numerically solve the Dirac equations describing the electron dynamics in quantum dots, and we demonstrate that compressible strips lead to the appearance of plateaus in the electron energies as a function of the magnetic field. Finally...

  8. The 'Big Karl' magnetic spectrometer - studies of the 103Ru transition nucleus with (d,p) and (p,d) reactions

    International Nuclear Information System (INIS)

    Huerlimann, W.

    1981-04-01

    The paper describes the structure and characteristics of the spectrometer and its application in a study of the 102 Ru(d,p) 103 Ru and 104 Ru(p,d) 103 Ru reactions. The study is structured as follows: To begin with the theoretical fundamentals, ion-optical characteristics and layout of BIG KARL are described. Field measurements and analyses carried out on the magnets of the spectrometer are described as well as the functioning of the 'Ht correction coils' used here for the first time to prevent faulty imaging. Chapter IV then describes methods employed so far to optimize resolution for large aperture angles of the spectrometer. Finally, chapter V investigates the 103 Ru transition nucleons on the basis of the 102 Ru(d,p) 103 RU and 104 Ru(p,d) 103 Ru transfer reactions measured in BIG KARL. (orig./HSI) [de

  9. Phenomena of non-thermal electrons from the X-ray imaging crystal spectrometer on J-TEXT tokamak

    International Nuclear Information System (INIS)

    Yan, W.; Chen, Z.Y.; Jin, W.; Huang, D.W.; Lee, S.G.; Shi, Y.J.; Tong, R.H.; Wang, S.Y.; Wei, Y.N.; Ma, T.K.; Zhuang, G.

    2016-01-01

    Highlights: • Some lines from X-ray imaging crystal spectrometer (XICS) can be enhanced by non-thermal electrons, such as q, r satellite lines and z lines. • Analyze the non-thermal phenomena can reduce the error of electron temperature deduced from the intensity ratio of different lines of the He-like argon spectra from XICS. • XICS can be a tool to measure the non-thermal phenomena from these enhanced lines. - Abstract: A high spectra resolution X-ray imaging crystal spectrometer has been implemented on J-TEXT Tokamak for the measurements of K_α spectra of helium-like argon and its satellite lines. The wavelength range of K_α spectra of helium-like argon is from 3.9494 Å to 3.9944 Å that includes the resonance line w, intercombination lines x and y, forbidden line z and numerous satellite lines, referenced using standard Gabriel notation. In low-density discharge, the intensity of q, r satellite lines and z lines can be significantly enhanced by non-thermal electrons. Non-thermal electrons are produced due to the low plasma density. The high hard X-ray flux from NaI detector and significant downshift electron cyclotron emissions from energetic runaway electrons also indicated that there is a large population of runaway electrons in the low-density discharge. The non-thermal part of electrons can affect the excitation/transition equilibrium or ionization/recombination equilibrium. The q line is mainly produced by inner-shell excitation of lithium-like argon, and the r line is partially produced by inner-shell excitation of lithium-like argon and dielectronic recombination of helium-like argon.

  10. Phenomena of non-thermal electrons from the X-ray imaging crystal spectrometer on J-TEXT tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Yan, W. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan (China); Chen, Z.Y., E-mail: zychen@hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan (China); Jin, W. [Center of Interface Dynamics for Sustainability, China Academy of Engineering Physics, Chengdu 610200, Sichuan (China); Huang, D.W. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan (China); Lee, S.G.; Shi, Y.J. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Tong, R.H.; Wang, S.Y.; Wei, Y.N.; Ma, T.K.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan (China)

    2016-11-01

    Highlights: • Some lines from X-ray imaging crystal spectrometer (XICS) can be enhanced by non-thermal electrons, such as q, r satellite lines and z lines. • Analyze the non-thermal phenomena can reduce the error of electron temperature deduced from the intensity ratio of different lines of the He-like argon spectra from XICS. • XICS can be a tool to measure the non-thermal phenomena from these enhanced lines. - Abstract: A high spectra resolution X-ray imaging crystal spectrometer has been implemented on J-TEXT Tokamak for the measurements of K{sub α} spectra of helium-like argon and its satellite lines. The wavelength range of K{sub α} spectra of helium-like argon is from 3.9494 Å to 3.9944 Å that includes the resonance line w, intercombination lines x and y, forbidden line z and numerous satellite lines, referenced using standard Gabriel notation. In low-density discharge, the intensity of q, r satellite lines and z lines can be significantly enhanced by non-thermal electrons. Non-thermal electrons are produced due to the low plasma density. The high hard X-ray flux from NaI detector and significant downshift electron cyclotron emissions from energetic runaway electrons also indicated that there is a large population of runaway electrons in the low-density discharge. The non-thermal part of electrons can affect the excitation/transition equilibrium or ionization/recombination equilibrium. The q line is mainly produced by inner-shell excitation of lithium-like argon, and the r line is partially produced by inner-shell excitation of lithium-like argon and dielectronic recombination of helium-like argon.

  11. Momentum reconstruction procedure for a nonfocusing spectrometer with wide-aperture analyzing magnet and nonuniform field

    International Nuclear Information System (INIS)

    Azhgirej, L.S.; Malinina, L.V.; Strokovskij, E.A.; Augustyniak, W.; Farhi, L.; Kunne, R.A.

    1999-01-01

    The SPES-4 spectrometer at SATURNE II has recently been equipped with a detection system working in coincidence with it. This system uses a wide-aperture dipole magnet. A method is described to determine the momentum vector and interaction vertex of the detected charged particle from its trajectory parameters measured outside the inhomogeneous field of the magnet. The feature of the set-up is that all detectors are placed outside the dipole field, while the target is inside the ∼ 1 T field and the incoming track is not measured. The feature of the method is that it is simple and fast, while it uses only the straight line part of the particle trajectory, which can be measured with sufficient accuracy

  12. Improved detection limits for electrospray ionization on a magnetic sector mass spectrometer by using an array detector.

    Science.gov (United States)

    Cody, R B; Tamura, J; Finch, J W; Musselman, B D

    1994-03-01

    Array detection was compared with point detection for solutions of hen egg-white lysozyme, equine myoglobin, and ubiquitin analyzed by electrospray ionization with a magnetic sector mass spectrometer. The detection limits for samples analyzed by using the array detector system were at least 10 times lower than could be achieved by using a point detector on the same mass spectrometer. The minimum detectable quantity of protein corresponded to a signal-to-background ratio of approximately 2∶1 for a 500 amol/μL solution of hen egg-white lysozyme. However, the ultimate practical sample concentrations appeared to be in the 10-100 fmol/μL range for the analysis of dilute solutions of relatively pure proteins or simple mixtures.

  13. Design of an electronic charged particle spectrometer to measure (ρR), yield, and implosion symmetry on the OMEGA Upgrade

    International Nuclear Information System (INIS)

    Hicks, D.G.; Li, C.K.; Petrasso, R.D.; Wenzel, K.W.; Knauer, J.P.

    1994-11-01

    The preliminary design for a state-of-the-art diagnostic that will measure a broad energy spectrum of charged particles generated in the OMEGA Upgrade facility is investigated. Using a set of photodiodes (∼10) and a 0.8 Tesla permanent magnet, the diagnostic will uniquely determine particle energies and identities from 0.2 MeV up to the maximum charged particle energies (10.6 MeV tritons, 12.5 MeV deuterons and 17.4 MeV protons). With its high density picture elements, each photodiode has 10 6 single-hit detectors, giving the spectrometer a dynamic range of 1 - 10 5 particles/shot. For example, in the case of a DT yield of 10 9 neutrons, about 100 knock-on charged particles will be detected when the spectrometer aperture is 60 cm from the implosion. Furthermore, the measurement of knock-on D and T spectra will allow ρR's up to 0.15 g/cm 2 to be measured (for a 1 keV plasma), or 0.3 g/cm 2 2 if hydrogen doping is used. In addition, the yield and slowing down of secondary protons may be used to determine ρR up to 0.3 g/cm 2 . Significantly, this diagnostic will also directly measure the DD fusion yield and energy degradation of nascent 3 MeV protons. By using two such compact spectrometers to measure the yield and spectra on widely separated ports around the OMEGA Upgrade target chamber, the implosion and bum symmetry can be determined. Furthermore, the ion temperature, and, in principle, even the electron temperature can be measured. The diagnostic and its development will be fully tested at several critical steps, utilizing 0.2-16 MeV protons (and several other charged particles and neutrons) from our absolutely calibrated Cockcroft-Walton facility

  14. Design and performance of a spin-polarized electron energy loss spectrometer with high momentum resolution

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyev, D.; Kirschner, J. [Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle (Germany)

    2016-08-15

    We describe a new “complete” spin-polarized electron energy loss spectrometer comprising a spin-polarized primary electron source, an imaging electron analyzer, and a spin analyzer of the “spin-polarizing mirror” type. Unlike previous instruments, we have a high momentum resolution of less than 0.04 Å{sup −1}, at an energy resolution of 90-130 meV. Unlike all previous studies which reported rather broad featureless data in both energy and angle dependence, we find richly structured spectra depending sensitively on small changes of the primary energy, the kinetic energy after scattering, and of the angle of incidence. The key factor is the momentum resolution.

  15. Test-electron analysis of the magnetic reconnection topology

    Science.gov (United States)

    Borgogno, D.; Perona, A.; Grasso, D.

    2017-12-01

    Three-dimensional (3D) investigations of the magnetic reconnection field topology in space and laboratory plasmas have identified the abidance of magnetic coherent structures in the stochastic region, which develop during the nonlinear stage of the reconnection process. Further analytical and numerical analyses highlighted the efficacy of some of these structures in limiting the magnetic transport. The question then arises as to what is the possible role played by these patterns in the dynamics of the plasma particles populating the chaotic region. In order to explore this aspect, we provide a detailed description of the nonlinear 3D magnetic field topology in a collisionless magnetic reconnection event with a strong guide field. In parallel, we study the evolution of a population of test electrons in the guiding-center approximation all along the reconnection process. In particular, we focus on the nonlinear spatial redistribution of the initially thermal electrons and show how the electron dynamics in the stochastic region depends on the sign and on the value of their velocities. While the particles with the highest positive speed populate the coherent current structures that survive in the chaotic sea, the presence of the manifolds calculated in the stochastic region defines the confinement area for the electrons with the largest negative velocity. These results stress the link between the magnetic topology and the electron motion and contribute to the overall picture of a non-stationary fluid magnetic reconnection description in a geometry proper to physical systems where the effects of the curvature can be neglected.

  16. Electronic and magnetic properties of ultrathin rhodium nanowires

    CERN Document Server

    Wang Bao Lin; Ren-Yun; Sun Hou Qian; Chen Xiao Shuang; Zhao Ji Jun

    2003-01-01

    The structures of ultrathin rhodium nanowires are studied using empirical molecular dynamics simulations with a genetic algorithm. Helical multishell cylindrical and pentagonal packing structures are found. The electronic and magnetic properties of the rhodium nanowires are calculated using an spd tight-binding Hamiltonian in the unrestricted Hartree-Fock approximation. The average magnetic moment and electronic density of states are obtained. Our results indicate that the electronic and magnetic properties of the rhodium nanowires depend not only on the size of the wire but also on the atomic structure. In particular, centred pentagonal and hexagonal structures can be unusually ferromagnetic.

  17. Automation of a thermal ionisation mass spectrometer

    International Nuclear Information System (INIS)

    Pamula, A.; Leuca, M.; Albert, S.; Benta, Adriana

    2001-01-01

    A thermal ionization mass spectrometer was upgraded in order to be monitored by a PC. A PC-LMP-16 National Instruments data acquisition board was used for the ion current channel and the Hall signal channel. A dedicated interface was built to allow commands from the computer to the current supply of the analyzing magnet and to the high voltage unit of the mass spectrometer. A software application was worked out to perform the adjustment of the spectrometer, magnetic scanning and mass spectra acquisition, data processing and isotope ratio determination. The apparatus is used for isotope ratio 235 U/ 238 U determination near the natural abundance. A peak jumping technique is applied to choose between the 235 U and 238 U signal, by switching the high voltage applied to the ion source between two preset values. This avoids the delay between the acquisition of the peaks of interest, a delay that would appear in the case of a 'pure' magnetic scanning. Corrections are applied for the mass discrimination effects and a statistical treatment of the data is achieved. (authors)

  18. Development of High-frequency Soft Magnetic Materials for Power Electronics

    Directory of Open Access Journals (Sweden)

    LIU Jun-chang

    2017-05-01

    Full Text Available The new requirements of high-frequency magnetic properties are put forward for electronic components with the rapid development of power electronics industry and the use of new electromagnetic materials. The properties of magnetic core, which is the key unit of electronic components, determine the performance of electronic components directly. Therefore, it's necessary to study the high-frequency soft magnetic materials. In this paper, the development history of four types of soft magnetic materials was reviewed. The advantages and disadvantages of each kind of soft magnetic materials and future development trends were pointed out. The emphases were placed on the popular soft magnetic composite materials in recent years. The tendency is to develop high-frequency soft magnetic composite materials with the particle size controllable, uniform coating layer on the core and a mass production method from laboratory to industrialization.

  19. Performance of the ATLAS muon spectrometer

    International Nuclear Information System (INIS)

    Aleksa, M.

    1999-09-01

    ATLAS is a general-purpose experiment for the future large hadron collider (LHC) at CERN. Its Muon Spectrometer will require ∼5500 m 2 of precision tracking chambers to measure the muon tracks along a spectrometer arm of 5 m to 15 m length, embedded in a magnetic field of ∼0.5 T. The precision tracking devices in the Muon System will be high pressure drift tubes (MDTs). Approximately 370,000 MDTs will be assembled into ∼1200 drift chambers. The LHC physics discovery range indicates the need for a momentum resolution of ∼10 % for muons with a transverse momentum of p T =1 TeV/c. Following a detailed engineering optimisation of the magnetic-field strength versus the chamber resolution, the ATLAS collaboration opted for a drift-chamber system with very high spatial resolution, σ 2 93/7). Measurements performed in a high-background environment - similar to the ATLAS operational environment - gave us a complete understanding of the individual effects which deteriorate the spatial resolution at high rates. Four effects responsible for a resolution deterioration have been identified: two electronics effects which depend on the count rate of a tube (baseline shift and baseline fluctuations), and two space-charge effects that depend on the local count rate (gain drop and field fluctuations). The understanding of these effects had a major impact on the choice of the drift gas and the front-end electronics. The strong dependence of the drift velocity on the drift field is one major disadvantage of the baseline gas. In this work the full set of effects which lead to systematic errors to the track-position measurement in one tube (e.g. variations of the background rate) was investigated and quantified for realistic LHC operating conditions. For the biggest effects analytical corrections are presented. Finally, the muon-system performance was investigated and a calibration method for the absolute mass scale developed. By means of simulation it was shown that the energy

  20. HISS spectrometer at LBL

    International Nuclear Information System (INIS)

    Greiner, D.

    1980-11-01

    The Heavy Ion Spectrometer System at LBL is designed to be a general purpose experimental work bench able to support a wide variety of experiments. Our philosophy is to provide instruments capable of investigating, with multi-particle sensitivity, a large portion of phase space. We have not chosen a particular region such as mid-rapidity or projectile frame but, instead, have made sure that the magnet and the instrumentation allow these choices as well as many others. The beam can be brought into the magnet at a variable position and the magnet can be rotated

  1. Spectrometer sensitivity calibration in the extreme uv by means of branching ratios of magnetic dipole lines

    International Nuclear Information System (INIS)

    Denne, B.; Hinnov, E.

    1984-04-01

    Relative intensity measurements of various line pairs resulting from magnetic dipole transitions within the configurations s 2 p 2 and s 2 p 4 , in conjunction with calculated transition probabilities, have been used to determine the wavelength dependence of the sensitivity of a grazing incidence spectrometer, in the range 400 to 1000 A. Emissions from Cr XIX, Fe XXI, Ni XXI and XXIII, Cu XXIV, and Zr XXVII ions in PLT tokamak discharges were used for this purpose. Absolute sensitivity of the spectrometer at selected wavelengths had been determined by the traditional hydrogen, helium, carbon, and oxygen electric-dipole line pairs from the same discharges. Similar attempts to use transitions in the s 2 p 3 configurations in Cr XVIII, Zr XXVI, and Mo XXVIII ions resulted in significant discrepancies that are ascribed to uncertainties in the corresponding calculated transition probabilities

  2. Magnetic moment of a bound electron

    CERN Document Server

    Czarnecki, Andrzej; Mondejar, Jorge; Piclum, Jan H

    2010-01-01

    Theoretical predictions underlying determinations of the fine structure constant alpha and the electron-to-proton mass ratio m_e/m_p are reviewed, with the emphasis on the bound electron magnetic anomaly g-2. The theory of the interaction of hydrogen-like ions with a magnetic field is discussed. The status of efforts aimed at the determination of O(alpha (Z alpha)^5) and O(alpha^2 (Z alpha)^5) corrections to the g factor is presented. The reevaluation of analogous corrections to the Lamb shift and the hyperfine splitting is summarized.

  3. Magnetic properties of confined electron gas

    International Nuclear Information System (INIS)

    Felicio, J.R.D. de.

    1977-04-01

    The effects of confinement by a two or three-dimensional harmonic potential on the magnetic properties of a free electron gas are investigated using the grand-canonical ensemble framework. At high temperatures an extension of Darwin's, Felderhof and Raval's works is made taking into account spin effects at low temperature. A comprehensive description of the magnetic properties of a free electron gas is given. The system is regarded as finite, but the boundary condition psi=0 is not introduced. The limits of weak and strong confinement are also analysed [pt

  4. The BTeV main spectrometer

    International Nuclear Information System (INIS)

    Sheldon, P.D.

    2001-01-01

    BTeV is a second generation B-factory experiment that will use a double-arm, forward spectrometer in the C0 experimental hall at the Fermilab Tevatron. I will describe the motivation and design of the 'main spectrometer', consisting of a ring-imaging Cherenkov system for charged particle identification, an electromagnetic calorimeter of lead-tungstate crystals, a proportional tube muon system with magnetized filtering steel, and a straw-tube and silicon strip charged particle tracking system

  5. Electron-Scale Measurements of Magnetic Reconnection in Space

    Science.gov (United States)

    Burch, J. L.; Torbert, R. B.; Phan, T. D.; Chen, L.-J.; Moore, T. E.; Ergun, R. E.; Eastwood, J. P.; Gershman, D. J.; Cassak, P. A.; Argall, M. R.; hide

    2016-01-01

    Magnetic reconnection is a fundamental physical process in plasmas whereby stored magnetic energy is converted into heat and kinetic energy of charged particles. Reconnection occurs in many astrophysical plasma environments and in laboratory plasmas. Using measurements with very high time resolution, NASA's Magnetospheric Multiscale (MMS) mission has found direct evidence for electron demagnetization and acceleration at sites along the sunward boundary of Earth's magnetosphere where the interplanetary magnetic field reconnects with the terrestrial magnetic field. We have (i) observed the conversion of magnetic energy to particle energy; (ii) measured the electric field and current, which together cause the dissipation of magnetic energy; and (iii) identified the electron population that carries the current as a result of demagnetization and acceleration within the reconnection diffusion/dissipation region.

  6. Novel time-of-flight spectrometer for the analysis of positron annihilation induced Auger electrons

    International Nuclear Information System (INIS)

    Hugenschmidt, Christoph; Legl, Stefan

    2006-01-01

    Positron annihilation induced Auger-electron spectroscopy (PAES) has several advantages over conventional Auger-electron spectroscopy such as extremely high surface sensitivity and outstanding signal-to-noise ratio at the Auger-transition energy. In order to benefit from these prominent features a low-energy positron beam of high intensity is required for surface sensitive PAES studies. In addition, an electron energy analyzer is required, which efficiently detects the Auger electrons with acceptable energy resolution. For this reason a novel time-of-flight (TOF) spectrometer has been developed at the intense positron source NEPOMUC that allows PAES studies within short measurement time. This TOF-PAES setup combines a trochoidal filter and a flight tube in a Faraday cage in order to achieve an improved energy resolution of about 1 eV at high electron energies up to E≅1000 eV. The electron flight time is the time between the annihilation radiation at the sample and when the electron hits a microchannel plate detector at the end of the flight tube

  7. High resolution solar soft X-ray spectrometer

    International Nuclear Information System (INIS)

    Zhang Fei; Wang Huanyu; Peng Wenxi; Liang Xiaohua; Zhang Chunlei; Cao Xuelei; Jiang Weichun; Zhang Jiayu; Cui Xingzhu

    2012-01-01

    A high resolution solar soft X-ray spectrometer (SOX) payload onboard a satellite is developed. A silicon drift detector (SDD) is adopted as the detector of the SOX spectrometer. The spectrometer consists of the detectors and their readout electronics, a data acquisition unit and a payload data handling unit. A ground test system is also developed to test SOX. The test results show that the design goals of the spectrometer system have been achieved. (authors)

  8. Magnetic effects in the paraxial regime of elastic electron scattering

    Science.gov (United States)

    Edström, Alexander; Lubk, Axel; Rusz, Ján

    2016-11-01

    Motivated by a recent claim [Phys. Rev. Lett. 116, 127203 (2016), 10.1103/PhysRevLett.116.127203] that electron vortex beams can be used to image magnetism at the nanoscale in elastic scattering experiments, using transmission electron microscopy, a comprehensive computational study is performed to study magnetic effects in the paraxial regime of elastic electron scattering in magnetic solids. Magnetic interactions from electron vortex beams, spin polarized electron beams, and beams with phase aberrations are considered, as they pass through ferromagnetic FePt or antiferromagnetic LaMnAsO. The magnetic signals are obtained by comparing the intensity over a disk in the diffraction plane for beams with opposite angular momentum or aberrations. The strongest magnetic signals are obtained from vortex beams with large orbital angular momentum, where relative magnetic signals above 10-3 are indicated for 10 ℏ orbital angular momentum, meaning that relative signals of one percent could be expected with the even larger orbital angular momenta, which have been produced in experimental setups. All results indicate that beams with low acceleration voltage and small convergence angles yield stronger magnetic signals, which is unfortunately problematic for the possibility of high spatial resolution imaging. Nevertheless, under atomic resolution conditions, relative magnetic signals in the order of 10-4 are demonstrated, corresponding to an increase with one order of magnitude compared to previous work.

  9. High intensity line source for x-ray spectrometer calibration

    International Nuclear Information System (INIS)

    Thoe, R.S.

    1986-06-01

    A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 μ x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10 4 ) time-resolved cyrstal spectrometer, will be discussed in detail

  10. Convenient determination of luminescence quantum yield using a combined electronic absorption and emission spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, John; Mishra, Ashok Kumar [Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India)

    2016-01-15

    It is possible to measure luminescence quantum yield in a facile way, by designing an optical spectrometer capable of obtaining electronic absorption as well as luminescence spectra, with a setup that uses the same light source and detector for both the spectral measurements. Employment of a single light source and single detector enables use of the same correction factor profile for spectral corrections. A suitable instrumental scaling factor is used for adjusting spectral losses.

  11. Efficiency calibration of electron spectrometers by the help of standard spectrum

    International Nuclear Information System (INIS)

    Toth, J.; Cserny, I.; Varga, D.; Koever, I.; Toekesi, K.

    2004-01-01

    Complete text of publication follows. For studying thin films and surface nanostructures quantitative analytical applications of electron spectroscopic techniques have a great importance. The most frequently used techniques are XPS, XAES and AES in quantitative surface electron spectroscopy. Applying these techniques changes in the detection efficiency vs. electron kinetic energy change the measured electron peak intensity ratios and in this way the neglect of the energy dependence of the spectrometer efficiency can influence surface atomic concentrations derived. The importance of the precise determination of the atomic concentrations is very crucial, especially in the determination of non-destructive depth profiles by the help of AR-XPS in which small changes in the relative concentrations can change dramatically the concentration depth profiles of a few nanometer depth ranges. In the present study the REELS technique was used to determine the relative detection efficiency by the help of a standard spectrum measured on the surface of fine microcrystalline Cu specimen. The experimental relative efficiency curves vs. electron kinetic energy were compared to the calculated efficiency curve. The efficiency calibration is discussed from the point of view of quantitative XPS, AR- XPS, AES and from the point of view of IMFP determination by XPS. The work was supported by the Hungarian National Science Foundation, OTKAT038016. For the Cu specimen and the standard spectrum the authors are indebted to the Sur- face Analysis Society of Japan, to Dr. Shigeo Tanuma and Professor Keisuke Goto (NIT). (author)

  12. Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy.

    Science.gov (United States)

    Hindle, Francis; Yang, Chun; Mouret, Gael; Cuisset, Arnaud; Bocquet, Robin; Lampin, Jean-François; Blary, Karine; Peytavit, Emilien; Akalin, Tahsin; Ducournau, Guillaume

    2009-01-01

    A review is provided of sources and detectors that can be employed in the THz range before the description of an opto-electronic source of monochromatic THz radiation. The realized spectrometer has been applied to gas phase spectroscopy. Air-broadening coefficients of HCN are determined and the insensitivity of this technique to aerosols is demonstrated by the analysis of cigarette smoke. A multiple pass sample cell has been used to obtain a sensitivity improvement allowing transitions of the volatile organic compounds to be observed. A solution to the frequency metrology is presented and promises to yield accurate molecular line center measurements.

  13. Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy

    Science.gov (United States)

    Hindle, Francis; Yang, Chun; Mouret, Gael; Cuisset, Arnaud; Bocquet, Robin; Lampin, Jean-François; Blary, Karine; Peytavit, Emilien; Akalin, Tahsin; Ducournau, Guillaume

    2009-01-01

    A review is provided of sources and detectors that can be employed in the THz range before the description of an opto-electronic source of monochromatic THz radiation. The realized spectrometer has been applied to gas phase spectroscopy. Air-broadening coefficients of HCN are determined and the insensitivity of this technique to aerosols is demonstrated by the analysis of cigarette smoke. A multiple pass sample cell has been used to obtain a sensitivity improvement allowing transitions of the volatile organic compounds to be observed. A solution to the frequency metrology is presented and promises to yield accurate molecular line center measurements. PMID:22291552

  14. Polarization and magnetization of electronic matter

    International Nuclear Information System (INIS)

    Beck, G.

    1979-01-01

    The behaviour of a system of spin-electrons in a weak external electric or magnetic field is studied. Already in the case of a single free electron classical and quantum theory lead to different results concerning the Lorentz transformation of the magnetic moment (Thomas factor of spin-orbit coupling). The separation of the current into a convection and a spin part can be performed in a covariant way. While the convection current is responsible for the diamagnetism of a system, the spin current accounts for paramagnetic behaviour. After a Lorentz transformation of a diamagnetic system paraelectric components appear, while a paramagnetic system, after rransformation, exhibits dia-electric properties, epsilon 1) after a Lorentz transformation shows diamagnetic components, while a diaelectric system would acquire paramagnetic behaviour. Quantum electrodynamics leads to the result, that Dirac's electron vacuum behaves like a paramagnetic medium. It follows from this result, that the electron vacuum in a weak external electric field represents a diaelectric system. (Author) [pt

  15. Fast Advection of Magnetic Fields by Hot Electrons

    International Nuclear Information System (INIS)

    Willingale, L.; Thomas, A. G. R.; Krushelnick, K.; Nilson, P. M.; Kaluza, M. C.; Dangor, A. E.; Evans, R. G.; Fernandes, P.; Haines, M. G.; Kamperidis, C.; Kingham, R. J.; Ridgers, C. P.; Sherlock, M.; Wei, M. S.; Najmudin, Z.; Bandyopadhyay, S.; Notley, M.; Minardi, S.; Tatarakis, M.; Rozmus, W.

    2010-01-01

    Experiments where a laser-generated proton beam is used to probe the megagauss strength self-generated magnetic fields from a nanosecond laser interaction with an aluminum target are presented. At intensities of 10 15 W cm -2 and under conditions of significant fast electron production and strong heat fluxes, the electron mean-free-path is long compared with the temperature gradient scale length and hence nonlocal transport is important for the dynamics of the magnetic field in the plasma. The hot electron flux transports self-generated magnetic fields away from the focal region through the Nernst effect [A. Nishiguchi et al., Phys. Rev. Lett. 53, 262 (1984)] at significantly higher velocities than the fluid velocity. Two-dimensional implicit Vlasov-Fokker-Planck modeling shows that the Nernst effect allows advection and self-generation transports magnetic fields at significantly faster than the ion fluid velocity, v N /c s ≅10.

  16. GEANT Monte Carlo simulations for the GREAT spectrometer

    International Nuclear Information System (INIS)

    Andreyev, A.N.; Butler, P.A.; Page, R.D.; Appelbe, D.E.; Jones, G.D.; Joss, D.T.; Herzberg, R.-D.; Regan, P.H.; Simpson, J.; Wadsworth, R.

    2004-01-01

    GEANT Monte Carlo simulations for the recently developed GREAT spectrometer are presented. Some novel applications of the spectrometer for γ-ray, conversion-electron and β-decay spectroscopy are discussed. The conversion-electron spectroscopy of heavy nuclei with strongly converted transitions and the extension of the recoil decay tagging method to β-decaying nuclei are considered in detail

  17. Electron Dynamics in a Subproton-Gyroscale Magnetic Hole

    Science.gov (United States)

    Gershman, Daniel J.; Dorelli, John C.; Vinas, Adolfo F.; Avanov, Levon A.; Gliese, Ulrik B.; Barrie, Alexander C.; Coffey, Victoria; Chandler, Michael; Dickson, Charles; MacDonald, Elizabeth A.; hide

    2016-01-01

    Magnetic holes are ubiquitous in space plasmas, occurring in the solar wind, downstream of planetary bow shocks, and inside the magnetosphere. Recently, kinetic-scale magnetic holes have been observed near Earth's central plasma sheet. The Fast Plasma Investigation on NASA's Magnetospheric Multiscale (MMS) mission enables measurement of both ions and electrons with 2 orders of magnitude increased temporal resolution over previous magnetospheric instruments. Here we present data from MMS taken in Earth's nightside plasma sheet and use high-resolution particle and magnetometer data to characterize the structure of a subproton-scale magnetic hole. Electrons with gyroradii above the thermal gyroradius but below the current layer thickness carry a current sufficient to account for a 10-20 depression in magnetic field magnitude. These observations suggest that the size and magnetic depth of kinetic-scale magnetic holes is strongly dependent on the background plasma conditions.

  18. Two-frequency radiospectrometer for studying paramagnetics under a strong magnetic field

    International Nuclear Information System (INIS)

    Vertii, A.A.; Gudym, I.Y.; Ivanchenko, I.V.

    1994-01-01

    A two-frequency radiospectrometer for studying electron paramagnetic resonance in the 120-150-GHz band and nuclear magnetic resonance in the 180-200-MHz band is described. The spectrometer is used to measure the properties of paramagnetics by a double-resonance technique in a magnetic field of up to 5 T at a temperature ranging from 1.7 to 20 degrees K

  19. Measurement of the electron and ion temperatures by the x-ray imaging crystal spectrometer on joint Texas experimental tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Yan, W.; Chen, Z. Y., E-mail: zychen@hust.edu.cn; Huang, D. W.; Tong, R. H.; Wang, S. Y.; Wei, Y. N.; Ma, T. K.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan (China); Jin, W. [Center of Interface Dynamics for Sustainability, China Academy of Engineering Physics, Chengdu, Sichuan 610200 (China); Lee, S. G. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Shi, Y. J. [Department of Nuclear Engineering, Seoul National University, Seoul 08826 (Korea, Republic of)

    2016-11-15

    An x-ray imaging crystal spectrometer has been developed on joint Texas experimental tokamak for the measurement of electron and ion temperatures from the K{sub α} spectra of helium-like argon and its satellite lines. A two-dimensional multi-wire proportional counter has been applied to detect the spectra. The electron and ion temperatures have been obtained from the Voigt fitting with the spectra of helium-like argon ions. The profiles of electron and ion temperatures show the dependence on electron density in ohmic plasmas.

  20. Exploring the Physics Limitations of Compact High Gradient Accelerating Structures Simulations of the Electron Current Spectrometer Setup in Geant4

    CERN Document Server

    Van Vliet, Philine Julia

    2017-01-01

    The high field gradient of 100 MV/m that will be applied to the accelerator cavities of the Compact Linear Collider (CLIC), gives rise to the problem of RF breakdowns. The field collapses and a plasma of electrons and ions is being formed in the cavity, preventing the RF field from penetrating the cavity. Electrons in the plasma are being accelerated and ejected out, resulting in a breakdown current up to a few Amp`eres, measured outside the cavities. These breakdowns lead to luminosity loss, so reducing their amount is of great importance. For this, a better understanding of the physics behind RF breakdowns is needed. To study these breakdowns, the XBox 2 test facility has a spectrometer setup installed after the RF cavity that is being conditioned. For this report, a simulation of this spectrometer setup has been made using Geant4. Once a detailed simulation of the RF field and cavity has been made, it can be connected to this simulation of the spectrometer setup and used to recreate the data that has b...

  1. Magnetic circular dichroism in electron microscopy

    Czech Academy of Sciences Publication Activity Database

    Rusz, Ján; Novák, Pavel; Rubino, S.; Hébert, C.; Schattschneider, P.

    2008-01-01

    Roč. 113, č. 1 (2008), s. 599-604 ISSN 0587-4246. [CSMAG'07. Košice, 09.07.2007-12.07.2007] EU Projects: European Commission(XE) 508971 - CHIRALTEM Institutional research plan: CEZ:AV0Z10100521 Keywords : magnetic circular dichroism * electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.321, year: 2008

  2. Electronic structures and magnetic/optical properties of metal phthalocyanine complexes

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Shintaro; Suzuki, Atsushi, E-mail: suzuki@mat.usp.ac.jp; Oku, Takeo [Department of Materials Science, The University of Shiga Prefecture. 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

    2016-02-01

    Electronic structures and magnetic / optical properties of metal phthalocyanine complexes were studied by quantum calculations using density functional theory. Effects of central metal and expansion of π orbital on aromatic ring as conjugation system on the electronic structures, magnetic, optical properties and vibration modes of infrared and Raman spectra of metal phthalocyanines were investigated. Electron and charge density distribution and energy levels near frontier orbital and excited states were influenced by the deformed structures varied with central metal and charge. The magnetic parameters of chemical shifts in {sup 13}C-nuclear magnetic resonance ({sup 13}C-NMR), principle g-tensor, A-tensor, V-tensor of electric field gradient and asymmetry parameters derived from the deformed structures with magnetic interaction of nuclear quadruple interaction based on electron and charge density distribution with a bias of charge near ligand under crystal field.

  3. Design, simulation and construction of quadrupole magnets for focusing electron beam in powerful industrial electron accelerator

    Directory of Open Access Journals (Sweden)

    S KH Mousavi

    2015-09-01

    Full Text Available In this paper the design and simulation of quadrupole magnets and electron beam optical of that by CST Studio code has been studied. Based on simulation result the magnetic quadrupole has been done for using in beam line of first Iranian powerful electron accelerator. For making the suitable magnetic field the effects of material and core geometry and coils current variation on quadrupole magnetic field have been studied. For test of quadrupole magnet the 10 MeV beam energy and 0.5 pi mm mrad emittance of input beam has been considered. We see the electron beam through the quadrupole magnet focus in one side and defocus in other side. The optimum of distance between two quadrupole magnets for low emittance have been achieved. The simulation results have good agreement with experimental results

  4. METHODOLOGICAL NOTES: Integrating magnetism into semiconductor electronics

    Science.gov (United States)

    Zakharchenya, Boris P.; Korenev, Vladimir L.

    2005-06-01

    The view of a ferromagnetic-semiconducting hybrid structure as a single tunable system is presented. Based on an analysis of existing experiments it is shown that, contrary to a 'common sense', a nonmagnetic semiconductor is capable of playing an important role in controlling ferromagnetism. Magnetic properties of a hybrid (the hysteresis loop and the spatial orientation of magnetization) can be tuned both optically and electrically by utilizing semiconductor—making the hybrid an electronic-write-in and electronic-read-out elementary storage unit.

  5. Dynamic shielding of the magnetic fields

    Directory of Open Access Journals (Sweden)

    RAU, M.

    2010-11-01

    Full Text Available The paper presents a comparative study of the methods used to control and compensate the direct and alternative magnetic fields. Two frequently used methods in the electromagnetic compatibility of the complex biomagnetism installations were analyzed. The two methods refer to the use of inductive magnetic field sensors (only for alternative fields and of fluxgate magnetometers as active transducers which measures both the direct and alternative components of the magnetic field. The applications of the dynamic control of the magnetic field are: control of the magnetic field of the military ships, control of parasite magnetic field produced by power transformers and the electrical networks, protection of the mass spectrometers, electronic microscopes, SQUID and optical pumping magnetometers for applications in biomagnetism.

  6. Search for “anomalies” from neutrino and anti-neutrino oscillations at $\\Delta_m^{2} ≈ 1eV^{2}$ with muon spectrometers and large LAr–TPC imaging detectors

    CERN Document Server

    Antonello, M; Baibussinov, B; Bilokon, H; Boffelli, F; Bonesini, M; Calligarich, E; Canci, N; Centro, S; Cesana, A; Cieslik, K; Cline, D B; Cocco, A G; Dequal, D; Dermenev, A; Dolfini, R; De Gerone, M; Dussoni, S; Farnese, C; Fava, A; Ferrari, A; Fiorillo, G; Garvey, G T; Gatti, F; Gibin, D; Gninenko, S; Guber, F; Guglielmi, A; Haranczyk, M; Holeczek, J; Ivashkin, A; Kirsanov, M; Kisiel, J; Kochanek, I; Kurepin, A; Łagoda, J; Lucchini, G; Louis, W C; Mania, S; Mannocchi, G; Marchini, S; Matveev, V; Menegolli, A; Meng, G; Mills, G B; Montanari, C; Nicoletto, M; Otwinowski, S; Palczewski, T J; Passardi, G; Perfetto, F; Picchi, P; Pietropaolo, F; Płonski, P; Rappoldi, A; Raselli, G L; Rossella, M; Rubbia, C; Sala, P; Scaramelli, A; Segreto, E; Stefan, D; Stepaniak, J; Sulej, R; Suvorova, O; Terrani, M; Tlisov, D; Van de Water, R G; Trinchero, G; Turcato, M; Varanini, F; Ventura, S; Vignoli, C; Wang, H G; Yang, X; Zani, A; Zaremba, K; Benettoni, M; Bernardini, P; Bertolin, A; Bozza, C; Brugnera, R; Cecchetti, A; Cecchini, S; Collazuol, G; Creti, P; Dal Corso, F; De Mitri, I; De Robertis, G; De Serio, M; Degli Esposti, L; Di Ferdinando, D; Dore, U; Dusini, S; Fabbricatore, P; Fanin, C; Fini, R A; Fiore, G; Garfagnini, A; Giacomelli, G; Giacomelli, R; Grella, G; Guandalini, C; Guerzoni, M; Kose, U; Laurenti, G; Laveder, M; Lippi, I; Loddo, F; Longhin, A; Loverre, P; Mancarella, G; Mandrioli, G; Margiotta, A; Marsella, G; Mauri, N; Medinaceli, E; Mengucci, A; Mezzetto, M; Michinelli, R; Muciaccia, M T; Orecchini, D; Paoloni, A; Pastore, A; Patrizii, L; Pozzato, M; Rescigno, R; Rosa, G; Simone, S; Sioli, M; Sirri, G; Spurio, M; Stanco, L; Stellacci, S; Surdo, A; Tenti, M; Togo, V; Ventura, M; Zago, M

    2012-01-01

    This proposal describes an experimental search for sterile neutrinos beyond the Standard Model with a new CERN-SPS neutrino beam. The experiment is based on two identical LAr-TPC's followed by magnetized spectrometers, observing the electron and muon neutrino events at 1600 and 300 m from the proton target. This project will exploit the ICARUS T600, moved from LNGS to the CERN "Far" position. An additional 1/4 of the T600 detector will be constructed and located in the "Near" position. Two spectrometers will be placed downstream of the two LAr-TPC detectors to greatly complement the physics capabilities. Spectrometers will exploit a classical dipole magnetic field with iron slabs, and a new concept air-magnet, to perform charge identification and muon momentum measurements in a wide energy range over a large transverse area. In the two positions, the radial and energy spectra of the nu_e beam are practically identical. Comparing the two detectors, in absence of oscillations, all cross sections and experimenta...

  7. Conversion electrons from high-statistics β-decay measurements with the 8π spectrometer at TRIUMF-ISAC

    Science.gov (United States)

    Garrett, P. E.; Jigmeddorj, B.; Radich, A. J.; Andreoiu, C.; Ball, G. C.; Bangay, J. C.; Bianco, L.; Bildstein, V.; Chagnon-Lessard, S.; Cross, D. S.; Demand, G. A.; Diaz Varela, A.; Dunlop, R.; Finlay, P.; Garnsworthy, A. B.; Green, K. L.; Hackman, G.; Hadinia, B.; Leach, K. G.; Michetti-Wilson, J.; Orce, J. N.; Rajabali, M. M.; Rand, E. T.; Starosta, K.; Sumithrarachchi, C.; Svensson, C. E.; Triambak, S.; Wang, Z. M.; Williams, S. J.; Wood, J. L.; Wong, J.; Yates, S. W.; Zganjar, E. F.

    2016-09-01

    The 8π spectrometer, located at TRIUMF-ISAC, was the world's most powerful spectrometer dedicated to β-decay studies until its decommissioning in early 2014 for replacement with the GRIFFIN array. An integral part of the 8π spectrometer was the Pentagonal Array for Conversion Electron Spectroscopy (PACES) consisting of 5 Si(Li) detectors used for charged-particle detection. PACES enabled both γ - e- and e- - e- coincidence measurements, which were crucial for increasing the sensitivity for discrete e- lines in the presence of large backgrounds. Examples from a 124Cs decay experiment, where the data were vital for the expansion of the 124Cs decay scheme, are shown. With suffcient statistics, measurements of conversion coeffcients can be used to extract the E0 components of Jπ → Jπ transitions for J ≠ 0, which is demonstrated for data obtained in 110In→110Cd decay. With knowledge of the shapes of the states involved, as obtained, for example, from the use of Kumar-Cline shape invariants, the mixing of the states can be extracted.

  8. Basics of spectroscopic instruments. Hardware of NMR spectrometer

    International Nuclear Information System (INIS)

    Sato, Hajime

    2009-01-01

    NMR is a powerful tool for structure analysis of small molecules, natural products, biological macromolecules, synthesized polymers, samples from material science and so on. Magnetic Resonance Imaging (MRI) is applicable to plants and animals Because most of NMR experiments can be done by an automation mode, one can forget hardware of NMR spectrometers. It would be good to understand features and performance of NMR spectrometers. Here I present hardware of a modern NMR spectrometer which is fully equipped with digital technology. (author)

  9. In situ transmission electron microscopy for magnetic nanostructures

    DEFF Research Database (Denmark)

    Ngo, Duc-The; Kuhn, Luise Theil

    2016-01-01

    Nanomagnetism is a subject of great interest because of both application and fundamental aspects in which understanding of the physical and electromagnetic structure of magnetic nanostructures is essential to explore the magnetic properties. Transmission electron microscopy (TEM) is a powerful tool...... that allows understanding of both physical structure and micromagnetic structure of the thin samples at nanoscale. Among TEM techniques, in situ TEM is the state-of-the-art approach for imaging such structures in dynamic experiments, reconstructing a real-time nanoscale picture of the properties......-structure correlation. This paper aims at reviewing and discussing in situ TEM magnetic imaging studies, including Lorentz microscopy and electron holography in TEM, applied to the research of magnetic nanostructures....

  10. Pulsed coherent spectrometer of nuclear magnetic and nuclear quadrupole resonance

    International Nuclear Information System (INIS)

    Karnachev, A.S.; Solov'ev, E.E.

    1996-01-01

    The spectrometer intended for studies on solid bodies was created on the basis of the X1-48 device for investigation of amplitude-frequency characteristics with the frequency range of 5-100 MHz, the receiver sensitivity by the signal-noise ratio at the outlet of 12 dB not worse than 0.5 μV and the feed-up capacity up to 80 W. The X1-48 minimal remodeling made it possible to use it in the spectrometer system as a signal feed-up source and measurer of the amplitude-frequency characteristic of the spectrometer receiver tract. 12 refs., 11 figs

  11. Particle astronomy with a superconducting magnet.

    Science.gov (United States)

    Buffington, A.

    1972-01-01

    The magnetic spectrometer measures deflections of charged particles moving in a magnetic field and provides a direct means of determining the rigidity of charged primary cosmic rays up to about 100 GV/c rigidity. The underlying concepts of the method are reviewed, and factors delineating the applicable momentum range and accuracy are described along with calibration techniques. Previous experiments employing this technique are summarized, and prospects for future applications are evaluated with emphasis on separate measurement of electron and positron spectra and on isotopic separation.

  12. Electronic and magnetic properties of 3d transition metal-doped strontium clusters: Prospective magnetic superatoms

    International Nuclear Information System (INIS)

    Chauhan, Vikas; Sen, Prasenjit

    2013-01-01

    Highlights: • Structural, electronic and magnetic properties of TM-Sr clusters are studied using DFT methods. • CrSr 9 and MnSr 10 have enhanced stability in the CrSr n and MnSrn series. • These two clusters behave as magnetic superatoms. • A qualitative understanding of the magnetic coupling between two superatom units is offered. • Reactivity of these superatoms to molecular oxygen also studied. - Abstract: Structural, electronic and magnetic properties of 3d transition metal doped strontium clusters are studied using first-principles electronic structure methods based on density functional theory. Clusters with enhanced kinetic and thermodynamic stability are identified by studying their hardness, second order energy difference and adiabatic spin excitation energy. CrSr 9 and MnSr 10 are found to have enhanced stability. They retain their structural identities in assemblies, and are classified as magnetic superatoms. A qualitative understanding of the magnetic coupling between two cluster units is arrived at. Reactivity of these superatoms with O 2 molecule is also studied. Prospects for using these magnetic superatoms in applications are discussed

  13. Intense synchrotron radiation from a magnetically compressed relativistic electron layer

    International Nuclear Information System (INIS)

    Shearer, J.W.; Nowak, D.A.; Garelis, E.; Condit, W.C.

    1975-10-01

    Using a simple model of a relativistic electron layer rotating in an axial magnetic field, energy gain by an increasing magnetic field and energy loss by synchrotron radiation were considered. For a typical example, initial conditions were approximately 8 MeV electron in approximately 14 kG magnetic field, at a layer radius of approximately 20 mm, and final conditions were approximately 4 MG magnetic field approximately 100 MeV electron layer energy at a layer radius of approximately 1.0 mm. In the final state, the intense 1-10 keV synchrotron radiation imposes an electron energy loss time constant of approximately 100 nanoseconds. In order to achieve these conditions in practice, the magnetic field must be compressed by an imploding conducting liner; preferably two flying rings in order to allow the synchrotron radiation to escape through the midplane. The synchrotron radiation loss rate imposes a lower limit to the liner implosion velocity required to achieve a given final electron energy (approximately 1 cm/μsec in the above example). In addition, if the electron ring can be made sufficiently strong (field reversed), the synchrotron radiation would be a unique source of high intensity soft x-radiation

  14. View of the Axial Field Spectrometer

    CERN Multimedia

    1980-01-01

    The Axial Field Spectrometer, with the vertical uranium/scintillator calorimeter and the central drift chamber retracted for service. One coil of the Open Axial Field Magnet is just visible to the right.

  15. Design of a wideband multilayer grating spectrometer for the study of electronic structure of thin-film CIS solar cells

    International Nuclear Information System (INIS)

    Imazono, Takashi; Koike, Masato; Kuramoto, Satoshi; Nagano, Tetsuya; Koeda, Masaru; Moriya, Naoji

    2014-01-01

    A soft x-ray emission spectrometer equipped with a wideband Ni/C multilayer-coated laminar-type varied-line-spacing holographic grating is designed to analyze the electronic structure in thin-film copper indium selenide (CIS) solar cells nondestructively by soft x-ray emission spectroscopy. The spectrometer equipped with the multilayer grating thus designed allows us to detect the L emission lines of Cu, In, and Se simultaneously from a CIS absorber layer in the 1–3.5 keV range at a constant angle of incidence. (author)

  16. Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy

    Directory of Open Access Journals (Sweden)

    Guillaume Ducournau

    2009-11-01

    Full Text Available A review is provided of sources and detectors that can be employed in the THz range before the description of an opto-electronic source of monochromatic THz radiation. The realized spectrometer has been applied to gas phase spectroscopy. Air-broadening coefficients of HCN are determined and the insensitivity of this technique to aerosols is demonstrated by the analysis of cigarette smoke. A multiple pass sample cell has been used to obtain a sensitivity improvement allowing transitions of the volatile organic compounds to be observed. A solution to the frequency metrology is presented and promises to yield accurate molecular line center measurements.

  17. Electronic response of rare-earth magnetic-refrigeration compounds GdX2 (X = Fe and Co)

    Science.gov (United States)

    Bhatt, Samir; Ahuja, Ushma; Kumar, Kishor; Heda, N. L.

    2018-05-01

    We present the Compton profiles (CPs) of rare-earth-transition metal compounds GdX2 (X = Fe and Co) using 740 GBq 137Cs Compton spectrometer. To compare the experimental momentum densities, we have also computed the CPs, electronic band structure, density of states (DOS) and Mulliken population (MP) using linear combination of atomic orbitals (LCAO) method. Local density and generalized gradient approximations within density functional theory (DFT) along with the hybridization of Hartree-Fock and DFT (B3LYP and PBE0) have been considered under the framework of LCAO scheme. It is seen that the LCAO-B3LYP based momentum densities give a better agreement with the experimental data for both the compounds. The energy bands and DOS for both the spin-up and spin-down states show metallic like character of the reported intermetallic compounds. The localization of 3d electrons of Co and Fe has also been discussed in terms of equally normalized CPs and MP data. Discussion on magnetization using LCAO method is also included.

  18. Study and outlook of Dimuon spectrometer of ALICE experiment at LHC

    International Nuclear Information System (INIS)

    1997-01-01

    The Dimuon spectrometer and its functional integration in the ALICE experiment, planned to work by the Large Hadron Collider at CERN, is briefly presented. The detection assembly consists of a hadron absorber placed near the interaction location, followed by a large dipole superconducting magnet of 4 m aperture and 3 T.m field integral for muon analysis in the rapidity range 2 to 4. The muon tracking is ensured by 5 detection stations bunching 1 million electronic paths on a total detection area of about 100 m 2 . The muon trigger system consists of 4 detection levels ensuring a 10 3 rejection of the incident hadrons. SUBATECH is implied in the tracking and trigger domains of the project. The tracking parameters, relating to spatial resolution, chamber efficiency, magnetic field integral, homogeneity, absorber composition, etc., were optimized in the laboratory. This technical effort was followed by further development of tracking chambers of the spectrometer, based on the MICROMEGAS (MICRO-MEsh-GAseous Structure) detector, conceived by G.Charpak, characterized by its fast response (200 ns) and high position resolution (σ = 100 μm). Larger detectors, with areas of the order of 1 m 2 , as well as, the optimization of readout electronics and associated data acquisition systems are the current preoccupations of a group of 3 physicists and 4 engineers and technicians. A second level muon trigger system was designed to obtain the invariant mass reconstruction for all the muons pairs that cross the first level Pt threshold. After a number of preparing simulations of the trigger system the design of the second level trigger electronics is now to be realized. This work is carried out by two assistant researchers, a post-doctoral researcher and an engineer

  19. Suprathermal electron studies in the TCV tokamak: Design of a tomographic hard-x-ray spectrometer

    International Nuclear Information System (INIS)

    Gnesin, S.; Coda, S.; Decker, J.; Peysson, Y.

    2008-01-01

    Electron cyclotron resonance heating and electron cyclotron current drive, disruptive events, and sawtooth activity are all known to produce suprathermal electrons in fusion devices, motivating increasingly detailed studies of the generation and dynamics of this suprathermal population. Measurements have been performed in the past years in the tokamak a configuration variable (TCV) tokamak using a single pinhole hard-x-ray (HXR) camera and electron-cyclotron-emission radiometers, leading, in particular, to the identification of the crucial role of spatial transport in the physics of ECCD. The observation of a poloidal asymmetry in the emitted suprathermal bremsstrahlung radiation motivates the design of a proposed new tomographic HXR spectrometer reported in this paper. The design, which is based on a compact modified Soller collimator concept, is being aided by simulations of tomographic reconstruction. Quantitative criteria have been developed to optimize the design for the greatly variable shapes and positions of TCV plasmas.

  20. Turbulence-driven anisotropic electron tail generation during magnetic reconnection

    Science.gov (United States)

    DuBois, A. M.; Scherer, A.; Almagri, A. F.; Anderson, J. K.; Pandya, M. D.; Sarff, J. S.

    2018-05-01

    Magnetic reconnection (MR) plays an important role in particle transport, energization, and acceleration in space, astrophysical, and laboratory plasmas. In the Madison Symmetric Torus reversed field pinch, discrete MR events release large amounts of energy from the equilibrium magnetic field, a fraction of which is transferred to electrons and ions. Previous experiments revealed an anisotropic electron tail that favors the perpendicular direction and is symmetric in the parallel. New profile measurements of x-ray emission show that the tail distribution is localized near the magnetic axis, consistent modeling of the bremsstrahlung emission. The tail appears first near the magnetic axis and then spreads radially, and the dynamics in the anisotropy and diffusion are discussed. The data presented imply that the electron tail formation likely results from a turbulent wave-particle interaction and provides evidence that high energy electrons are escaping the core-localized region through pitch angle scattering into the parallel direction, followed by stochastic parallel transport to the plasma edge. New measurements also show a strong correlation between high energy x-ray measurements and tearing mode dynamics, suggesting that the coupling between core and edge tearing modes is essential for energetic electron tail formation.

  1. Magnetic holes in the dipolarized magnetotail: ion and electron anisotropies

    Science.gov (United States)

    Shustov, P.; Artemyev, A.; Zhang, X. J.; Yushkov, E.; Petrukovich, A. A.

    2017-12-01

    We conduct statistics on magnetic holes observed by THEMIS spacecraft in the near-Earth magnetotail. Groups of holes are detected after dipolarizations in the quiet, equatorial plasma sheet. Magnetic holes are characterized by significant magnetic field depressions (up to 50%) and strong electron currents ( 10-50 nA/m2), with spatial scales much smaller than the ion gyroradius. These magnetic holes are populated by hot (>10 keV), transversely anisotropic electrons supporting the pressure balance. We present statistical properties of these sub-ion scale magnetic holes and discuss possible mechanisms on the hole formation.

  2. Observation of Magnetic Induction Distribution by Scanning Interference Electron Microscopy

    Science.gov (United States)

    Takahashi, Yoshio; Yajima, Yusuke; Ichikawa, Masakazu; Kuroda, Katsuhiro

    1994-09-01

    A scanning interference electron microscope (SIEM) capable of observing magnetic induction distribution with high sensitivity and spatial resolution has been developed. The SIEM uses a pair of fine coherent scanning probes and detects their relative phase change by magnetic induction, giving raster images of microscopic magnetic distributions. Its performance has been demonstrated by observing magnetic induction distributed near the edge of a recorded magnetic storage medium. Obtained images are compared with corresponding images taken in the scanning Lorentz electron microscope mode using the same microscope, and the differences between them are discussed.

  3. The Magnetic Recoil Spectrometer for time-resolved neutron measurements (MRSt) at the NIF

    Science.gov (United States)

    Parker, C. E.; Frenje, J. A.; Wink, C. W.; Gatu Johnson, M.; Lahmann, B.; Li, C. K.; Seguin, F. H.; Petrasso, R. D.; Hilsabeck, T. J.; Kilkenny, J. D.; Bionta, R.; Casey, D. T.; Khater, H. Y.; Forrest, C. J.; Glebov, V. Yu.; Sorce, C.; Hares, J. D.; Siegmund, O. H. W.

    2017-10-01

    The next-generation Magnetic Recoil Spectrometer, called MRSt, will provide time-resolved measurements of the DT-neutron spectrum. These measurements will provide critical information about the time evolution of the fuel assembly, hot-spot formation, and nuclear burn in Inertial Confinement Fusion (ICF) implosions at the National Ignition Facility (NIF). The neutron spectrum in the energy range 12-16 MeV will be measured with high accuracy ( 5%), unprecedented energy resolution ( 100 keV) and, for the first time ever, time resolution ( 20 ps). An overview of the physics motivation, conceptual design for meeting these performance requirements, and the status of the offline tests for critical components will be presented. This work was supported in part by the U.S. DOE, LLNL, and LLE.

  4. Magnetic fluctuations and heavy electron superconductivity

    International Nuclear Information System (INIS)

    Norman, M.R.

    1988-01-01

    A magnetic fluctuation self-energy based on neutron scattering data is used to calculate mass renormalizations, and superconducting critical temperatures and order parameters, for various heavy electron metals

  5. Increases of equatorial total electron content (TEC) during magnetic storms

    International Nuclear Information System (INIS)

    Yeboah-Amankwah, D.

    1976-01-01

    This paper is a report on the analysis of equatorial electron content, TEC, during magnetic storms. Storms between 1969 and 1972 have been examined as part of an on-going study of TEC morphology during magnetically disturbed days. The published magnetic Ksup(p) indices and TEC data from the Legon abservatory have been employed. The general picture arising from the analysis is that the total electron content of the ionosphere is significantly enhanced during magnetic storms. (author)

  6. Electronic module for control of sample feeding device of spectrometers of X-ray fluorescent analysis of CRV type

    International Nuclear Information System (INIS)

    Petrov, V.A.; Fursov, A.V.

    2002-01-01

    The scheme of electronic module for sample feeding device control for the CRV type X-ray fluorescence analysis spectrometers is considered. This module provides realization of next functions: sample change operations and installation in starting position; signaling and defense at emergency cases; indication of any sample amount in the spectrometer chamber; testing function at tuning and testing of modules. All these principal functions are entrusted with microcontroller. Programming of the microcontroller is putting into effect by algorithm of the whole sample feeding device. In the capacity of microcontroller the single crystalline processor PICI16C54 and stepping motor of NV-306-V2202 model have been used

  7. Modelling the line shape of very low energy peaks of positron beam induced secondary electrons measured using a time of flight spectrometer

    International Nuclear Information System (INIS)

    Fairchild, A J; Chirayath, V A; Gladen, R W; Chrysler, M D; Koymen, A R; Weiss, A H

    2017-01-01

    In this paper, we present results of numerical modelling of the University of Texas at Arlington’s time of flight positron annihilation induced Auger electron spectrometer (UTA TOF-PAES) using SIMION® 8.1 Ion and Electron Optics Simulator. The time of flight (TOF) spectrometer measures the energy of electrons emitted from the surface of a sample as a result of the interaction of low energy positrons with the sample surface. We have used SIMION® 8.1 to calculate the times of flight spectra of electrons leaving the sample surface with energies and angles dispersed according to distribution functions chosen to model the positron induced electron emission process and have thus obtained an estimate of the true electron energy distribution. The simulated TOF distribution was convolved with a Gaussian timing resolution function and compared to the experimental distribution. The broadening observed in the simulated TOF spectra was found to be consistent with that observed in the experimental secondary electron spectra of Cu generated as a result of positrons incident with energy 1.5 eV to 901 eV, when a timing resolution of 2.3 ns was assumed. (paper)

  8. Astrophysics and particle physics in space with the Alpha Magnetic Spectrometer

    CERN Document Server

    Lamanna, G

    2003-01-01

    The Alpha Magnetic Spectrometer is a high energy particle physics experiment in space scheduled to be installed on the International Space Station (ISS) by 2006 for a three-year mission. After a precursor flight of a prototype detector on board of the NASA Space Shuttle in June 1998, the construction of the detector in its final configuration is started and it will be completed by 2004. The purpose of this experiment is to provide a high statistics measurement of charged particles and nuclei in rigidity range 0.5 GV to few TV and to explore the high-energy (>1 GeV) gamma-ray sky. In this paper we describe the detector layout and present an overview of the main scientific goals both in the domain of astrophysics: cosmic- ray origin, age and propagation and the exploration of the most energetic gamma-ray sources; and in the domain of astroparticle: the antimatter and the dark matter searches. (53 refs).

  9. Reversed magnetic shear suppression of electron-scale turbulence on NSTX

    Science.gov (United States)

    Yuh, Howard Y.; Levinton, F. M.; Bell, R. E.; Hosea, J. C.; Kaye, S. M.; Leblanc, B. P.; Mazzucato, E.; Smith, D. R.; Domier, C. W.; Luhmann, N. C.; Park, H. K.

    2009-11-01

    Electron thermal internal transport barriers (e-ITBs) are observed in reversed (negative) magnetic shear NSTX discharges^1. These e-ITBs can be created with either neutral beam heating or High Harmonic Fast Wave (HHFW) RF heating. The e-ITB location occurs at the location of minimum magnetic shear determined by Motional Stark Effect (MSE) constrained equilibria. Statistical studies show a threshold condition in magnetic shear for e-ITB formation. High-k fluctuation measurements at electron turbulence wavenumbers^3 have been made under several different transport regimes, including a bursty regime that limits temperature gradients at intermediate magnetic shear. The growth rate of fluctuations has been calculated immediately following a change in the local magnetic shear, resulting in electron temperature gradient relaxation. Linear gyrokinetic simulation results for NSTX show that while measured electron temperature gradients exceed critical linear thresholds for ETG instability, growth rates can remain low under reversed shear conditions up to high electron temperatures gradients. ^1H. Yuh, et. al., PoP 16, 056120 ^2D.R. Smith, E. Mazzucato et al., RSI 75, 3840 ^3E. Mazzucato, D.R. Smith et al., PRL 101, 075001

  10. Magnetized relativistic electron-ion plasma expansion

    Science.gov (United States)

    Benkhelifa, El-Amine; Djebli, Mourad

    2016-03-01

    The dynamics of relativistic laser-produced plasma expansion across a transverse magnetic field is investigated. Based on a one dimensional two-fluid model that includes pressure, enthalpy, and rest mass energy, the expansion is studied in the limit of λD (Debye length) ≤RL (Larmor radius) for magnetized electrons and ions. Numerical investigation conducted for a quasi-neutral plasma showed that the σ parameter describing the initial plasma magnetization, and the plasma β parameter, which is the ratio of kinetic to magnetic pressure are the key parameters governing the expansion dynamics. For σ ≪ 1, ion's front shows oscillations associated to the break-down of quasi-neutrality. This is due to the strong constraining effect and confinement of the magnetic field, which acts as a retarding medium slowing the plasma expansion.

  11. Electron cloud in various kinds of magnetic field of BEPCII

    International Nuclear Information System (INIS)

    Liu Yudong; Guo Zhiyuan; Qin Qing; Wang Jiuqing

    2006-01-01

    Electron cloud instability (ECI) may take place in a positron storage ring when the machine is operated with a multi-bunch positron beam. According to the actual shape of the vacuum chamber in the BEPCII, a programme which is different from the other simulation codes has been developed. Because of the distance between dipole magnet and sextupole, the quadrupole magnet of BEPCII is very short, much of the photoelectrons can be produced and can move in magnetic fields. The motion of electrons in various kinds of magnetic fields is studied in detail, especially for the solenoid field which will be wound in the vacuum pipe of BEPCII. Simulation shows that the solenoid field is very effective to confine the electrons to the vicinity of the vacuum chamber wall and to make an electron free region at the vacuum pipe centre. (authors)

  12. A NMR spectrometer for educational purposes; Espectrometro de RMN para ensino

    Energy Technology Data Exchange (ETDEWEB)

    Colnago, Luiz A; Torre Neto, Andre [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Nucleo de Pesquisa e Desenvolvimento de Instrumentacao Agropecuaria; Villar, Jose D.F.; Seidl, Peter R [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

    1992-12-31

    A NMR spectrometer has been constructed for educational purposes, such as teaching of the technique basic principles and instrumentation. The spectrometer has been designed with a minimum number of components so that the students may have acquittance with both the spectrometer, through block diagrams, and the small numbers of existent components . The device was based on a 0.t Tesla magnet from the continuous wave spectrometer (E M 300 - Varian) existent at the Instituto Militar de Engenharia, and it is expected to facilitate the comprehension of the commercial spectrometers 1 ref., 3 figs.

  13. Magnetic field manipulation of spin current in a single-molecule magnet tunnel junction with two-electron Coulomb interaction

    Science.gov (United States)

    Zhang, Chao; Yao, Hui; Nie, Yi-Hang; Liang, Jiu-Qing; Niu, Peng-Bin

    2018-04-01

    In this work, we study the generation of spin-current in a single-molecule magnet (SMM) tunnel junction with Coulomb interaction of transport electrons and external magnetic field. In the absence of field the spin-up and -down currents are symmetric with respect to the initial polarizations of molecule. The existence of magnetic field breaks the time-reversal symmetry, which leads to unsymmetrical spin currents of parallel and antiparallel polarizations. Both the amplitude and polarization direction of spin current can be controlled by the applied magnetic field. Particularly when the magnetic field increases to a certain value the spin-current with antiparallel polarization is reversed along with the magnetization reversal of the SMM. The two-electron occupation indeed enhances the transport current compared with the single-electron process. However the increase of Coulomb interaction results in the suppression of spin-current amplitude at the electron-hole symmetry point. We propose a scheme to compensate the suppression with the magnetic field.

  14. Magnetic Properties of Electron-Doped LaCoO3

    Science.gov (United States)

    Tomiyasu, Keisuke; Sato, Mika; Koyama, Shun-Ichi; Nojima, Tsutomu; Kajimoto, Ryoichi; Ji, Sungdae; Iwasa, Kazuaki

    2017-09-01

    We studied electron-doped LaCo1 - yTey6 + O3 by magnetization measurements and neutron scattering. The effective Bohr magneton, estimated by Curie-Weiss fitting around room temperature, is independent of y. This suggests that magnetic Co3+(HS), not nonmagnetic Co3+(LS), is mainly replaced by doped magnetic Co2+(HS). At the lowest temperatures, a Brillouin-function-like saturating behavior persists in the magnetization curves even in the high-y samples, and neither a clear magnetic reflection nor magnetic dispersion is observed by neutron scattering. These findings indicate that the magnetic correlation is very weak, in contrast to the well-known hole-doped LaCoO3 accompanied by a drastic transition to a ferromagnetic metal. However, we also found that the low-y samples exhibit nonnegligible enhancement of the saturated magnetization by ˜2μB per a doped electron. All these characteristics are discussed in the light of the activation and inactivation of a spin-state blockade.

  15. Molecular Structure Laboratory. Fourier Transform Nuclear Magnetic Resonance (FTNMR) Spectrometer and Ancillary Instrumentation at SUNY Geneseo

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, David K [State Univ. of New York (SUNY), Geneseo, NY (United States)

    2015-12-31

    An Agilent 400-MR nuclear magnetic resonance (NMR) spectrometer and ancillary equipment were purchased, which are being used for molecular structure elucidation.  The instrumentation is housed in a pre-existing facility designed specifically for its use. This instrument package is being used to expand the research and educational efforts of the faculty and students at SUNY-Geneseo and is made available to neighboring educational institutions and business concerns.  Funds were also used for training of College personnel, maintenance of the instrumentation, and installation of the equipment.

  16. Simulations of space charge neutralization in a magnetized electron cooler

    Energy Technology Data Exchange (ETDEWEB)

    Gerity, James [Texas A-M; McIntyre, Peter M. [Texas A-M; Bruhwiler, David Leslie [RadiaSoft, Boulder; Hall, Christopher [RadiaSoft, Boulder; Moens, Vince Jan [Ecole Polytechnique, Lausanne; Park, Chong Shik [Fermilab; Stancari, Giulio [Fermilab

    2017-02-02

    Magnetized electron cooling at relativistic energies and Ampere scale current is essential to achieve the proposed ion luminosities in a future electron-ion collider (EIC). Neutralization of the space charge in such a cooler can significantly increase the magnetized dynamic friction and, hence, the cooling rate. The Warp framework is being used to simulate magnetized electron beam dynamics during and after the build-up of neutralizing ions, via ionization of residual gas in the cooler. The design follows previous experiments at Fermilab as a verification case. We also discuss the relevance to EIC designs.

  17. The CHAOS spectrometer for pion physics at TRIUMF

    International Nuclear Information System (INIS)

    Smith, G.R.; Amaudruz, P.A.; Brack, J.T.

    1994-12-01

    The Canadian high acceptance orbit spectrometer (CHAOS) is a unique magnetic spectrometer system recently commissioned for studies of pion induced reactions at TRIUMF. It is based on a cylindrical dipole magnet producing vertical magnetic fields up to 1.6 T. The scattering target is located in the center of the magnet. Charged particle tracks produced by pion interactions there are identified using four concentric cylindrical wire chambers surrounding the target. Particle identification and track multiplicity are determined by cylindrical layers of scintillation counters and lead glass Cerenkov counters, which also provide a first level trigger. A sophisticated second level trigger system permits pion fluxes in excess of 5 MHz to be employed. The detector subtends 360 o in the horizontal plane, and ±7 o out of this plane for a solid angle coverage approximately 10% of 4π sr. The momentum resolution delivered by the detector system is 1% (σ). (author). 16 refs., 12 figs

  18. Development of a Multi-GeV spectrometer for laser-plasma experiment at FLAME

    Science.gov (United States)

    Valente, P.; Anelli, F.; Bacci, A.; Batani, D.; Bellaveglia, M.; Benocci, R.; Benedetti, C.; Cacciotti, L.; Cecchetti, C. A.; Clozza, A.; Cultrera, L.; Di Pirro, G.; Drenska, N.; Faccini, R.; Ferrario, M.; Filippetto, D.; Fioravanti, S.; Gallo, A.; Gamucci, A.; Gatti, G.; Ghigo, A.; Giulietti, A.; Giulietti, D.; Gizzi, L. A.; Koester, P.; Labate, L.; Levato, T.; Lollo, V.; Londrillo, P.; Martellotti, S.; Pace, E.; Pathak, N.; Rossi, A.; Tani, F.; Serafini, L.; Turchetti, G.; Vaccarezza, C.

    2011-10-01

    The advance in laser-plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular, the upcoming experiments with the 250 TW laser at the FLAME facility of the INFN Laboratori Nazionali di Frascati, will enter the GeV regime with more than 100 pC of electrons. At the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need for developing a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV), with still unknown angular divergences. Within the PlasmonX experiment at FLAME, a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence, present challenges in the design and construction of such a device. We present the design considerations for this spectrometer that lead to the use of scintillating fibers, multichannel photo-multipliers and a multiplexing electronics, a combination which is innovative in the field. We also present the experimental results obtained with a high intensity electron beam performed on a prototype at the LNF beam test facility.

  19. Development of a Multi-GeV spectrometer for laser-plasma experiment at FLAME

    International Nuclear Information System (INIS)

    Valente, P.; Anelli, F.; Bacci, A.; Batani, D.; Bellaveglia, M.; Benocci, R.; Benedetti, C.; Cacciotti, L.; Cecchetti, C.A.; Clozza, A.; Cultrera, L.; Di Pirro, G.; Drenska, N.; Faccini, R.; Ferrario, M.; Filippetto, D.; Fioravanti, S.; Gallo, A.; Gamucci, A.; Gatti, G.

    2011-01-01

    The advance in laser-plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular, the upcoming experiments with the 250 TW laser at the FLAME facility of the INFN Laboratori Nazionali di Frascati, will enter the GeV regime with more than 100 pC of electrons. At the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need for developing a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV), with still unknown angular divergences. Within the PlasmonX experiment at FLAME, a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence, present challenges in the design and construction of such a device. We present the design considerations for this spectrometer that lead to the use of scintillating fibers, multichannel photo-multipliers and a multiplexing electronics, a combination which is innovative in the field. We also present the experimental results obtained with a high intensity electron beam performed on a prototype at the LNF beam test facility.

  20. Layered Black Phosphorus: Strongly Anisotropic Magnetic, Electronic, and Electron-Transfer Properties.

    Science.gov (United States)

    Sofer, Zdeněk; Sedmidubský, David; Huber, Štěpán; Luxa, Jan; Bouša, Daniel; Boothroyd, Chris; Pumera, Martin

    2016-03-01

    Layered elemental materials, such as black phosphorus, exhibit unique properties originating from their highly anisotropic layered structure. The results presented herein demonstrate an anomalous anisotropy for the electrical, magnetic, and electrochemical properties of black phosphorus. It is shown that heterogeneous electron transfer from black phosphorus to outer- and inner-sphere molecular probes is highly anisotropic. The electron-transfer rates differ at the basal and edge planes. These unusual properties were interpreted by means of calculations, manifesting the metallic character of the edge planes as compared to the semiconducting properties of the basal plane. This indicates that black phosphorus belongs to a group of materials known as topological insulators. Consequently, these effects render the magnetic properties highly anisotropic, as both diamagnetic and paramagnetic behavior can be observed depending on the orientation in the magnetic field. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Experimental test of nuclear magnetization distribution and nuclear structure models

    International Nuclear Information System (INIS)

    Beirsdorfer, P; Crespo-Lopez-Urrutia, J R; Utter, S B.

    1999-01-01

    stringent bounds on the models predicting currents and magnetic fields in the nucleus. We have implemented our method by constructing a very high-resolution spectrometer sensitive to light near 3800 A, which is the wavelength of light corresponding to the hyperfine splitting of the orbital of a single electron bound to a thallium nucleus, Tl 80+ . The spectrometer is unique in its design and consists of two independent arms separated by 90 ampersand deg;, each with an ultra sensitive CCD camera, a large-diameter transmission grating, and various focusing elements The spectrometer was successfully tested at the Livermore EBIT facility using the lower energy device, EBIT-II, and found to produce results to an accuracy of about 1 part in 65,000 with typical line widths on the order of 5.5 channels of the CCD detector, or equivalently, 0.55 A. Despite the breakdown of SuperEBIT, 98-LW-057 was successful in creating new capabilities unique to LLNL. High-precision measurements in the near-UV domain made possible with the development of this unique spectrometer system, coupled with the diverse capabilities of an electron beam ion trap, provide a pathway for the undertaking of scientifically and programmatically interesting measurements that test our fundamental knowledge of the physical world, such as the nuclear magnetization measurements we set out to do, as well as provide necessary data for the understanding of high-temperature plasmas

  2. Magnetic collimation and metal foil filtering for electron range and fluence modulation

    International Nuclear Information System (INIS)

    Phaisangittisakul, N.; D'Souza, W.D.; Ma Lijun

    2004-01-01

    We investigated the use of magnetically collimated electron beams together with metal filters for electron fluence and range modulation. A longitudinal magnetic field collimation method was developed to reduce skin dose and to improve the electron beam penumbra. Thin metal foils were used to adjust the energies of magnetically collimated electrons. The effects for different types of foils such as Al, Be, Cu, Pb, and Ti were studied using Monte Carlo calculations. An empirical pencil beam dose calculation model was developed to calculate electron dose distributions under magnetic collimation and foil modulation. An optimization method was developed to produce conformal dose distributions for simulated targets such as a horseshoe-shaped target. Our results show that it is possible to produce an electron depth dose enhancement peak using similar techniques of producing a spread-out Bragg peak. In conclusion, our study demonstrates new aspects of using magnetic collimation and foil filtration for producing fluence and range modulated electron dose distributions

  3. Bent crystal spectrometer for both frequency and wavenumber resolved x-ray scattering at a seeded free-electron laser.

    Science.gov (United States)

    Zastrau, Ulf; Fletcher, Luke B; Förster, Eckhart; Galtier, Eric Ch; Gamboa, Eliseo; Glenzer, Siegfried H; Heimann, Philipp; Marschner, Heike; Nagler, Bob; Schropp, Andreas; Wehrhan, Ortrud; Lee, Hae Ja

    2014-09-01

    We present a cylindrically curved GaAs x-ray spectrometer with energy resolution ΔE/E = 1.1 × 10(-4) and wave-number resolution of Δk/k = 3 × 10(-3), allowing plasmon scattering at the resolution limits of the Linac Coherent Light Source (LCLS) x-ray free-electron laser. It spans scattering wavenumbers of 3.6 to 5.2/Å in 100 separate bins, with only 0.34% wavenumber blurring. The dispersion of 0.418 eV/13.5 μm agrees with predictions within 1.3%. The reflection homogeneity over the entire wavenumber range was measured and used to normalize the amplitude of scattering spectra. The proposed spectrometer is superior to a mosaic highly annealed pyrolytic graphite spectrometer when the energy resolution needs to be comparable to the LCLS seeded bandwidth of 1 eV and a significant range of wavenumbers must be covered in one exposure.

  4. Magnetic turbulent electron transport in a reversed field pinch

    International Nuclear Information System (INIS)

    Schoenberg, K.; Moses, R.

    1990-01-01

    A model of magnetic turbulent electron transport is presented. The model, based on the thermal conduction theory of Rechester and Rosenbluth, entails a Boltzmann description of electron dynamics in the long mean-free-path limit and quantitatively describes the salient features of superthermal electron measurements in the RFP edge plasma. Included are predictions of the mean superthermal electron energy, current density, and power flux asymmetry. A discussion of the transport model, the assumptions implicit in the model, and the relevance of this work to more general issue of magnetic turbulent transport in toroidal systems is presented. 32 refs., 3 figs

  5. Electronic and magnetic properties of MnAu nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, Safi 46000 (Morocco); LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); Hlil, E.K. [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France); Hamedoun, M. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Benyoussef, A. [LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); Mounkachi, O; El moussaoui, H. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco)

    2014-03-15

    Self-consistent ab initio calculations, based on DFT (Density Functional Theory) approach and using FLAPW (Full potential Linear Augmented Plane Wave) method, are performed to investigate both electronic and magnetic properties of the MnAu nanoparticles. Polarized spin is included in calculations within the framework of the antiferromagnetic. The Mn magnetic moments where considered to be along c axes. Obtained data from ab initio calculations are used as input for the high temperature series expansions (HTSEs) calculations to compute other magnetic parameters. The zero-field high temperature static susceptibility series of the magnetic moment (m) and nearest-neighbour Heisenberg and XY models on a MnAu nanoparticles is thoroughly analyzed by means of a power series coherent anomaly method (CAM) for different nanoparticles. The exchanges interactions between the magnetic atoms are obtained for MnAu nanoparticles. - Highlights: • The electronic properties of the MnAu nanoparticles are studied using the DFT and FLAPW. • Magnetic moment is computed. • The ab initio calculations are used as input for HTSEs to compute other magnetic parameters. • The exchanges interactions and blocking temperature are obtained for MnAu nanoparticles.

  6. Electronic and magnetic properties of MnAu nanoparticles

    International Nuclear Information System (INIS)

    Masrour, R.; Hlil, E.K.; Hamedoun, M.; Benyoussef, A.; Mounkachi, O; El moussaoui, H.

    2014-01-01

    Self-consistent ab initio calculations, based on DFT (Density Functional Theory) approach and using FLAPW (Full potential Linear Augmented Plane Wave) method, are performed to investigate both electronic and magnetic properties of the MnAu nanoparticles. Polarized spin is included in calculations within the framework of the antiferromagnetic. The Mn magnetic moments where considered to be along c axes. Obtained data from ab initio calculations are used as input for the high temperature series expansions (HTSEs) calculations to compute other magnetic parameters. The zero-field high temperature static susceptibility series of the magnetic moment (m) and nearest-neighbour Heisenberg and XY models on a MnAu nanoparticles is thoroughly analyzed by means of a power series coherent anomaly method (CAM) for different nanoparticles. The exchanges interactions between the magnetic atoms are obtained for MnAu nanoparticles. - Highlights: • The electronic properties of the MnAu nanoparticles are studied using the DFT and FLAPW. • Magnetic moment is computed. • The ab initio calculations are used as input for HTSEs to compute other magnetic parameters. • The exchanges interactions and blocking temperature are obtained for MnAu nanoparticles

  7. Electron vortex magnetic holes: A nonlinear coherent plasma structure

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, Christopher T., E-mail: c.t.haynes@qmul.ac.uk; Burgess, David; Sundberg, Torbjorn [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Camporeale, Enrico [Multiscale Dynamics, Centrum Wiskunde and Informatica (CWI), Amsterdam (Netherlands)

    2015-01-15

    We report the properties of a novel type of sub-proton scale magnetic hole found in two dimensional particle-in-cell simulations of decaying turbulence with a guide field. The simulations were performed with a realistic value for ion to electron mass ratio. These structures, electron vortex magnetic holes (EVMHs), have circular cross-section. The magnetic field depression is associated with a diamagnetic azimuthal current provided by a population of trapped electrons in petal-like orbits. The trapped electron population provides a mean azimuthal velocity and since trapping preferentially selects high pitch angles, a perpendicular temperature anisotropy. The structures arise out of initial perturbations in the course of the turbulent evolution of the plasma, and are stable over at least 100 electron gyroperiods. We have verified the model for the EVMH by carrying out test particle and PIC simulations of isolated structures in a uniform plasma. It is found that (quasi-)stable structures can be formed provided that there is some initial perpendicular temperature anisotropy at the structure location. The properties of these structures (scale size, trapped population, etc.) are able to explain the observed properties of magnetic holes in the terrestrial plasma sheet. EVMHs may also contribute to turbulence properties, such as intermittency, at short scale lengths in other astrophysical plasmas.

  8. Magnetospheric Multiscale Observations of Electron Vortex Magnetic Hole in the Turbulent Magnetosheath Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Huang, S. Y.; Yuan, Z. G.; Wang, D. D.; Yu, X. D. [School of Electronic Information, Wuhan University, Wuhan (China); Sahraoui, F.; Contel, O. Le [Laboratoire de Physique des Plasmas, CNRS-Ecole Polytechnique-UPMC, Palaiseau (France); He, J. S. [School of Earth and Space Sciences, Peking University, Beijing (China); Zhao, J. S. [Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing (China); Deng, X. H.; Pang, Y.; Li, H. M. [Institute of Space Science and Technology, Nanchang University, Nanchang (China); Zhou, M. [Department of Physics and Astronomy, University of California, Los Angeles, CA (United States); Fu, H. S.; Yang, J. [School of Space and Environment, Beihang University, Beijing (China); Shi, Q. Q. [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai (China); Lavraud, B. [Institut de Recherche and Astrophysique et Planétologie, Université de Toulouse (UPS), Toulouse (France); Pollock, C. J.; Giles, B. L. [NASA, Goddard Space Flight Center, Greenbelt, MD (United States); Torbert, R. B. [University of New Hampshire, Durham, NH (United States); Russell, C. T., E-mail: shiyonghuang@whu.edu.cn [Department of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA (United States); and others

    2017-02-20

    We report on the observations of an electron vortex magnetic hole corresponding to a new type of coherent structure in the turbulent magnetosheath plasma using the Magnetospheric Multiscale mission data. The magnetic hole is characterized by a magnetic depression, a density peak, a total electron temperature increase (with a parallel temperature decrease but a perpendicular temperature increase), and strong currents carried by the electrons. The current has a dip in the core region and a peak in the outer region of the magnetic hole. The estimated size of the magnetic hole is about 0.23 ρ {sub i} (∼30 ρ {sub e}) in the quasi-circular cross-section perpendicular to its axis, where ρ {sub i} and ρ {sub e} are respectively the proton and electron gyroradius. There are no clear enhancements seen in high-energy electron fluxes. However, there is an enhancement in the perpendicular electron fluxes at 90° pitch angle inside the magnetic hole, implying that the electrons are trapped within it. The variations of the electron velocity components V {sub em} and V {sub en} suggest that an electron vortex is formed by trapping electrons inside the magnetic hole in the cross-section in the M – N plane. These observations demonstrate the existence of a new type of coherent structures behaving as an electron vortex magnetic hole in turbulent space plasmas as predicted by recent kinetic simulations.

  9. Handheld spectrometers: the state of the art

    Science.gov (United States)

    Crocombe, Richard A.

    2013-05-01

    "Small" spectrometers fall into three broad classes: small versions of laboratory instruments, providing data, subsequently processed on a PC; dedicated analyzers, providing actionable information to an individual operator; and process analyzers, providing quantitative or semi-quantitative information to a process controller. The emphasis of this paper is on handheld dedicated analyzers. Many spectrometers have historically been large, possible fragile, expensive and complicated to use. The challenge over the last dozen years, as instruments have moved into the field, has been to make spectrometers smaller, affordable, rugged, easy-to-use, but most of all capable of delivering actionable results. Actionable results can dramatically improve the efficiency of a testing process and transform the way business is done. There are several keys to this handheld spectrometer revolution. Consumer electronics has given us powerful mobile platforms, compact batteries, clearly visible displays, new user interfaces, etc., while telecomm has revolutionized miniature optics, sources and detectors. While these technologies enable miniature spectrometers themselves, actionable information has demanded the development of rugged algorithms for material confirmation, unknown identification, mixture analysis and detection of suspicious materials in unknown matrices. These algorithms are far more sophisticated than the `correlation' or `dot-product' methods commonly used in benchtop instruments. Finally, continuing consumer electronics advances now enable many more technologies to be incorporated into handheld spectrometers, including Bluetooth, wireless, WiFi, GPS, cameras and bar code readers, and the continued size shrinkage of spectrometer `engines' leads to the prospect of dual technology or `hyphenated' handheld instruments.

  10. Characterization of electromagnetic fields in the aSPECT spectrometer and reduction of systematic errors

    Energy Technology Data Exchange (ETDEWEB)

    Ayala Guardia, Fidel

    2011-10-15

    The aSPECT spectrometer has been designed to measure, with high precision, the recoil proton spectrum of the free neutron decay. From this spectrum, the electron antineutrino angular correlation coefficient a can be extracted with high accuracy. The goal of the experiment is to determine the coefficient a with a total relative error smaller than 0.3%, well below the current literature value of 5%. First measurements with the aSPECT spectrometer were performed in the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich. However, time-dependent background instabilities prevented us from reporting a new value of a. The contents of this thesis are based on the latest measurements performed with the aSPECT spectrometer at the Institut Laue-Langevin (ILL) in Grenoble, France. In these measurements, background instabilities were considerably reduced. Furthermore, diverse modifications intended to minimize systematic errors and to achieve a more reliable setup were successfully performed. Unfortunately, saturation effects of the detector electronics turned out to be too high to determine a meaningful result. However, this and other systematics were identified and decreased, or even eliminated, for future aSPECT beamtimes. The central part of this work is focused on the analysis and improvement of systematic errors related to the aSPECT electromagnetic fields. This work yielded in many improvements, particularly in the reduction of the systematic effects due to electric fields. The systematics related to the aSPECT magnetic field were also minimized and determined down to a level which permits to improve the present literature value of a. Furthermore, a custom NMR-magnetometer was developed and improved during this thesis, which will lead to reduction of magnetic field-related uncertainties down to a negligible level to determine a with a total relative error of at least 0.3%.

  11. Electron-inertia effects on driven magnetic field reconnection

    International Nuclear Information System (INIS)

    Al-Salti, N.; Shivamoggi, B.K.

    2003-01-01

    Electron-inertia effects on the magnetic field reconnection induced by perturbing the boundaries of a slab of plasma with a magnetic neutral surface inside are considered. Energetics of the tearing mode dynamics with electron inertia which controls the linearized collisionless magnetohydrodynamics (MHD) are considered with a view to clarify the role of the plasma pressure in this process. Cases with the boundaries perturbed at rates slow or fast compared with the hydromagnetic evolution rate are considered separately. When the boundaries are perturbed at a rate slow compared with the hydromagnetic evolution rate and fast compared with the resistive diffusion rate, the plasma response for early times is according to ideal MHD. A current sheet formation takes place at the magnetic neutral surface for large times in the ideal MHD stage and plasma becomes motionless. The subsequent evolution of the current sheet is found to be divided into two distinct stages: (i) the electron-inertia stage for small times (when the current sheet is very narrow); (ii) the resistive-diffusion stage for large times. The current sheet mainly undergoes exponential damping in the electron-inertia regime while the bulk of the diffusion happens in the resistivity regime. For large times of the resistive-diffusion stage when plasma flow is present, the current sheet completely disappears and the magnetic field reconnection takes place. When the boundaries are perturbed at a rate fast compared even with the hydromagnetic evolution rate, there is no time for the development of a current sheet and the magnetic field reconnection has been found not to take place

  12. In-situ magnetization/heating electron holography to study the magnetic ordering in arrays of nickel metallic nanowires

    Directory of Open Access Journals (Sweden)

    Eduardo Ortega

    2018-05-01

    Full Text Available Magnetic nanostructures of different size, shape, and composition possess a great potential to improve current technologies like data storage and electromagnetic sensing. In thin ferromagnetic nanowires, their magnetization behavior is dominated by the competition between magnetocrystalline anisotropy (related to the crystalline structure and shape anisotropy. In this way electron diffraction methods like precession electron diffraction (PED can be used to link the magnetic behavior observed by Electron Holography (EH with its crystallinity. Using off-axis electron holography under Lorentz conditions, we can experimentally determine the magnetization distribution over neighboring nanostructures and their diamagnetic matrix. In the case of a single row of nickel nanowires within the alumina template, the thin TEM samples showed a dominant antiferromagnetic arrangement demonstrating long-range magnetostatic interactions playing a major role.

  13. Effects of electron inertia in collisionless magnetic reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Andrés, Nahuel, E-mail: nandres@iafe.uba.ar; Gómez, Daniel [Instituto de Astronomía y Física del Espacio, CC. 67, suc. 28, 1428, Buenos Aires (Argentina); Departamento de Física, Facultad de Ciencias Exactas y Naturales, Univrsidad de Buenos Aires, Pabellón I, 1428, Buenos Aires (Argentina); Martin, Luis; Dmitruk, Pablo [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Univrsidad de Buenos Aires, Pabellón I, 1428, Buenos Aires (Argentina)

    2014-07-15

    We present a study of collisionless magnetic reconnection within the framework of full two-fluid MHD for a completely ionized hydrogen plasma, retaining the effects of the Hall current, electron pressure and electron inertia. We performed 2.5D simulations using a pseudo-spectral code with no dissipative effects. We check that the ideal invariants of the problem are conserved down to round-off errors. Our numerical results confirm that the change in the topology of the magnetic field lines is exclusively due to the presence of electron inertia. The computed reconnection rates remain a fair fraction of the Alfvén velocity, which therefore qualifies as fast reconnection.

  14. The resonance between runaway electrons and magnetic ripple in HT-7 Tokamak

    International Nuclear Information System (INIS)

    Zhou Ruijie; Hu Liqun; Lu Hongwei; Lin Shiyao; Zhong Guoqiang; Xu Ping; Zhang Jizong

    2011-01-01

    For suppressing the energy of runaway electrons in tokamak plasma, we analyzed the X-ray energy spectra by runaway electrons in different discharges of the HT-7 tokamak experiment performed in the autumn of 2009. The resonant phenomenon between runaway electrons and magnetic ripple was found. Although, the energy of runaway electrons in the plasma core can be as high as several tens of MeV, but when they are transported to the edge, the electron energy are limited to a certain range by resonance with the magnetic ripple of different harmonic numbers. The runaway electrons under high loop voltage resonate with low step magnetic perturbations, with high energy gain; whereas the runaway electrons under low loop voltage resonate with high level magnetic perturbations, with low energy gain. Using this mechanism, the energy of runaway electrons can be restricted to a low level, and this will significantly mitigate the damage effect on the equipment caused by runaway electrons. (authors)

  15. Observations of electron vortex magnetic holes and related wave-particle interactions in the turbulent magnetosheath

    Science.gov (United States)

    Huang, S.; Sahraoui, F.; Yuan, Z.; He, J.; Zhao, J.; Du, J.; Le Contel, O.; Wang, X.; Deng, X.; Fu, H.; Zhou, M.; Shi, Q.; Breuillard, H.; Pang, Y.; Yu, X.; Wang, D.

    2017-12-01

    Magnetic hole is characterized by a magnetic depression, a density peak, a total electron temperature increase (with a parallel temperature decrease but a perpendicular temperature increase), and strong currents carried by the electrons. The current has a dip in the core region of the magnetic hole and a peak in the outer region of the magnetic hole. There is an enhancement in the perpendicular electron fluxes at 90° pitch angles inside the magnetic hole, implying that the electrons are trapped within it. The variations of the electron velocity components Vem and Ven suggest that an electron vortex is formed by trapping electrons inside the magnetic hole in the circular cross-section. These observations demonstrate the existence of a new type of coherent structures behaving as an electron vortex magnetic hole in turbulent space plasmas as predicted by recent kinetic simulations. We perform a statistically study using high time solution data from the MMS mission. The magnetic holes with short duration (i.e., < 0.5 s) have their cross section smaller than the ion gyro-radius. Superposed epoch analysis of all events reveals that an increase in the electron density and total temperature, significantly increase (resp. decrease) the electron perpendicular (resp. parallel) temperature, and an electron vortex inside the holes. Electron fluxes at 90° pitch angles with selective energies increase in the KSMHs, are trapped inside KSMHs and form the electron vortex due to their collective motion. All these features are consistent with the electron vortex magnetic holes obtained in 2D and 3D particle-in-cell simulations, indicating that the observed the magnetic holes seem to be best explained as electron vortex magnetic holes. It is furthermore shown that the magnetic holes are likely to heat and accelerate the electrons. We also investigate the coupling between whistler waves and electron vortex magnetic holes. These whistler waves can be locally generated inside electron

  16. Rotating double arm spectrometer to study hard scattering interactions at Serpukhov accelerator

    International Nuclear Information System (INIS)

    Abramov, V.V.; Baldin, B.Yu.; Buzulutskov, A.F.

    1991-01-01

    The double arm magnetic spectrometer designed to study high P T particle production with intense proton and pion beams is described. Particle trajectories are measured by the drift and proportional chambers. Particles are identified by Cherenkov ring spectrometer and muon identifier. The spectrometer can be rotated around the target up to 160 mrad. 2 tabs.; 13 figs

  17. Trigger electronics for the forward and backward hodoscopes of ANKE

    International Nuclear Information System (INIS)

    Dymov, S.N.; Komarov, V.I.; Kulikov, A.V.; Merzlyakov, S.I.; Petrus, A.Yu.; Zhuravlev, N.I.; Mussgiller, A.

    2002-01-01

    Trigger electronics of the forward and backward scintillation hodoscopes of ANKE, the magnetic spectrometer placed at the internal beam line of the COSY-Juelich accelerator, is described. The two developed sets of trigger electronic modules are implemented in the whole ANKE trigger system and are used for the running experiments. For selection of double particle events in the hodoscope both the combinatory logic and the charge discrimination are used

  18. Electron emission relevant to inner-shell photoionization of condensed water studied by multi-electron coincidence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hikosaka, Y., E-mail: hikosaka@las.u-toyama.ac.jp [Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan); Mashiko, R.; Konosu, Y.; Soejima, K. [Department of Environmental Science, Niigata University, Niigata 950-2181 (Japan); Shigemasa, E. [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); SOKENDAI, Okazaki 444-8585 (Japan)

    2016-11-15

    Highlights: • Multi-electron coincidence spectroscopy is applied to the study of electron emissions from condensed H2O molecules. • Coincidence Auger spectra are obtained for different photoelectron energies. • The energy distribution of the slow electrons ejected in the Auger decay is deduced from three-fold coincidences. - Abstract: Multi-electron coincidence spectroscopy using a magnetic-bottle electron spectrometer has been applied to the study of the Auger decay following O1s photoionization of condensed H{sub 2}O molecules. Coincidence Auger spectra are obtained for three different photoelectron energy ranges. In addition, the energy distribution of the slow electrons ejected in the Auger decay of the O1s core hole is deduced from three-fold coincidences.

  19. The magnetic spectrometer PAMELA for the study of cosmic antimatter in space

    International Nuclear Information System (INIS)

    Basini, G.; Hof, M.; Barbiellini, G.; Boezio, M.; Bellotti, R.; Cafagna, F.

    1995-01-01

    In the framework of the RIM (Russian Italian mission) program, PAMELA is the experiment devoted to the accurate measurement of the positron and antiproton spectra from the very low energy thresh-old of 100 MeV up to more than 50 GeV, and to hunt antinuclei with sensitivity better than 10 -7 in the helium/helium ratio. A permanent magnet equipped by microstrip silicon sensors, measures the particle momentum with MDR=400 GV/c on GF=25 cm 2 sr. An accurate ToF system, a 19 X o deep imaging calorimeter, an aerogel Cherenkov counter and a TRD detector complement the spectrometer in order an efficient e +- /p +- separation and some light isotope identification capability. The PAMELA experiment will be carried out on a 700 km high polar orbit, on board of the Earth-observation meteor-3A satellite, to be launched at the end of 1988

  20. Laser ionization time of flight mass spectrometer for isotope mass detection and elemental analysis of materials

    Science.gov (United States)

    Ahmed, Nasar; Ahmed, Rizwan; Umar, Z. A.; Aslam Baig, M.

    2017-08-01

    In this paper we present the construction and modification of a linear time-of-flight mass spectrometer to improve its mass resolution. This system consists of a laser ablation/ionization section based on a Q-switched Nd:YAG laser (532 nm, 500 mJ, 5 ns pulse duration) integrated with a one meter linear time-of-flight mass spectrometer coupled with an electric sector and a magnetic lens and outfitted with a channeltron electron multiplier for ion detection. The resolution of the system has been improved by optimizing the accelerating potential and inserting a magnetic lens after the extraction region. The isotopes of lithium, lead and cadmium samples have been resolved and detected in accordance with their natural abundance. The capability of the system has been further exploited to determine the elemental composition of a brass alloy, having a certified composition of zinc and copper. Our results are in excellent agreement with its certified composition. This setup is found to be extremely efficient and convenient for fast analyses of any solid sample.

  1. Dynamic stabilization of the magnetic field surrounding the neutron electric dipole moment spectrometer at the Paul Scherrer Institute

    Energy Technology Data Exchange (ETDEWEB)

    Afach, S.; Fertl, M.; Franke, B., E-mail: beatrice.franke@psi.ch, E-mail: bernhard.lauss@psi.ch; Kirch, K. [Paul Scherrer Institute, Villigen (Switzerland); Institute for Particle Physics, Eidgenössische Technische Hochschule, Zürich (Switzerland); Bison, G.; Burri, F.; Chowdhuri, Z.; Daum, M.; Henneck, R.; Lauss, B., E-mail: beatrice.franke@psi.ch, E-mail: bernhard.lauss@psi.ch; Meier, M.; Schmidt-Wellenburg, P.; Zsigmond, G. [Paul Scherrer Institute, Villigen (Switzerland); Bodek, K.; Zejma, J. [Jagellonian University, Cracow (Poland); Grujic, Z.; Kasprzak, M.; Weis, A. [University of Fribourg (Switzerland); Hélaine, V. [Laboratoire de Physique Corpusculaire, Caen (France); Paul Scherrer Institute, Villigen (Switzerland); Koch, H.-C. [Institut für Physik, Johannes-Gutenberg-Universität, Mainz (Germany); University of Fribourg (Switzerland); and others

    2014-08-28

    The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of the neutron electric dipole moment spectrometer located at the Paul Scherrer Institute. The SFC system reduces the DC component of the external magnetic field by a factor of about 20. Within a control volume of approximately 2.5 m × 2.5 m × 3 m, disturbances of the magnetic field are attenuated by factors of 5–50 at a bandwidth from 10{sup −3} Hz up to 0.5 Hz, which corresponds to integration times longer than several hundreds of seconds and represent the important timescale for the neutron electric dipole moment measurement. These shielding factors apply to random environmental noise from arbitrary sources. This is achieved via a proportional-integral feedback stabilization system that includes a regularized pseudoinverse matrix of proportionality factors which correlates magnetic field changes at all sensor positions to current changes in the SFC coils.

  2. Monte Carlo characterization of clinical electron beams in transverse magnetic fields

    International Nuclear Information System (INIS)

    Lee, Michael C.; Ma, Chang-Ming

    2000-01-01

    Monte Carlo simulations were employed to study the characteristics of the electron beams of a clinical linear accelerator in the presence of 1.5 and 3.0 T transverse magnetic fields and to assess the possibility of using magnetic fields in conjunction with modulated electron radiation therapy (MERT). The starting depth of the magnetic field was varied over several centimetres. It was found that peak doses of as much as 2.7 times the surface dose could be achieved with a 1.5 T magnetic field. The magnetic field was shown to reduce the 80% and 20% dose drop-off distance by 50% to 80%. The distance between the 80% dose levels of the pseudo-Bragg peak induced by the magnetic field was found to be extremely narrow, generally less than 1 cm. However, by modulating the energy and intensity of the electron fields while simultaneously moving the magnetic field, a homogeneous dose distribution with low surface dose and a sharp dose fall-off was generated. Heterogeneities are shown to change the effective range of the electron beams, but not eliminate the advantages of a sharp depth-dose drop-off or high peak-to-surface dose ratio. This suggests the applicability of MERT with magnetic fields in heterogeneous media. The results of this study demonstrate the ability to use magnetic fields in MERT to produce highly desirable dose distributions. (author)

  3. Magnetic and electronic properties of some actinide intermetallic compounds

    International Nuclear Information System (INIS)

    Yaar, Ilan

    1992-06-01

    The electronic structure and magnetic properties of the light actinide intermetallic compounds are often related to interplay between localized and itinerant (band like) behavior of the 5f- electrons. In the present work, the properties of some actinide, mainly Np, intermetallic compounds were studied by Mossbauer effect, ac and dc susceptibility, X-ray and Neutron diffraction techniques. 1. NpX 2 (X=Ga,Si) - Both compounds order ferromagnetically at TC=55(2) and 48(2) K respectively. A comparison of our data with the results for other NpX 2 (X=Al,As,Sb,Tl) compounds indicates that NpGa 2 is a highly localized 5f electron system, whereas in NpSi 2 the 5f electrons are partially delocalized. The magnetic properties of NpX 2 compounds can neither be consistently explained within the conventional crystal electric field picture (CEF) nor by takink into account hybridization dressing of local spin density models. 2. NpX 3 (X=Ga,Si,In,Al) in the cubic AuCu 3 (Pm3m) crystallographic structure - From the Mossbauer isomer shift (IS) data we argue that the Np ion in the NpX 3 family is close to the formal 3+ (5I 4 ) charge state. The magnetic moment of the Np in NpSi 3 is totally suppressed whereas in NpGa 3 and NpAl 3 a localized (narrow band) moment is established. However, in NpIn 3 at 4.2 K, a modulated magnetic moment (0-1.5μB) is observed. Comparing the magnetic behavior of the NpX 3 family (X=Si,Ge,Ga, Al,In and Sn), we find an impressive variation of the magnetic properties, from temperature independent paramagnetism (TIP), localized and modulated ordered moments, to the formation of a concentrated Kondo lattice. Hybridization of 5f electrons with ligand electrons appears to play a crucial role in establishing these magnetic properties. However, at present a consistent theoretical picture can not be drawn. 3. XFe 4 Al 8 (X=Ho,Np,U) spin galss (SG) systems in the ThMn 12 (I 4 /mmm) crystallographic structure - Localized and itinerant behaviour of the f electrons

  4. Electronic and magnetic properties of small rhodium clusters

    Energy Technology Data Exchange (ETDEWEB)

    Soon, Yee Yeen; Yoon, Tiem Leong [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lim, Thong Leng [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia)

    2015-04-24

    We report a theoretical study of the electronic and magnetic properties of rhodium-atomic clusters. The lowest energy structures at the semi-empirical level of rhodium clusters are first obtained from a novel global-minimum search algorithm, known as PTMBHGA, where Gupta potential is used to describe the atomic interaction among the rhodium atoms. The structures are then re-optimized at the density functional theory (DFT) level with exchange-correlation energy approximated by Perdew-Burke-Ernzerhof generalized gradient approximation. For the purpose of calculating the magnetic moment of a given cluster, we calculate the optimized structure as a function of the spin multiplicity within the DFT framework. The resultant magnetic moments with the lowest energies so obtained allow us to work out the magnetic moment as a function of cluster size. Rhodium atomic clusters are found to display a unique variation in the magnetic moment as the cluster size varies. However, Rh{sub 4} and Rh{sub 6} are found to be nonmagnetic. Electronic structures of the magnetic ground-state structures are also investigated within the DFT framework. The results are compared against those based on different theoretical approaches available in the literature.

  5. Chiral magnetism of magnetic adatoms generated by Rashba electrons

    Science.gov (United States)

    Bouaziz, Juba; dos Santos Dias, Manuel; Ziane, Abdelhamid; Benakki, Mouloud; Blügel, Stefan; Lounis, Samir

    2017-02-01

    We investigate long-range chiral magnetic interactions among adatoms mediated by surface states spin-splitted by spin-orbit coupling. Using the Rashba model, the tensor of exchange interactions is extracted wherein a thepseudo-dipolar interaction is found, in addition to the usual isotropic exchange interaction and the Dzyaloshinskii-Moriya interaction. We find that, despite the latter interaction, collinear magnetic states can still be stabilized by the pseudo-dipolar interaction. The interadatom distance controls the strength of these terms, which we exploit to design chiral magnetism in Fe nanostructures deposited on a Au(111) surface. We demonstrate that these magnetic interactions are related to superpositions of the out-of-plane and in-plane components of the skyrmionic magnetic waves induced by the adatoms in the surrounding electron gas. We show that, even if the interatomic distance is large, the size and shape of the nanostructures dramatically impacts on the strength of the magnetic interactions, thereby affecting the magnetic ground state. We also derive an appealing connection between the isotropic exchange interaction and the Dzyaloshinskii-Moriya interaction, which relates the latter to the first-order change of the former with respect to spin-orbit coupling. This implies that the chirality defined by the direction of the Dzyaloshinskii-Moriya vector is driven by the variation of the isotropic exchange interaction due to the spin-orbit interaction.

  6. Simulation study on avoiding runaway electron generation by magnetic perturbations

    International Nuclear Information System (INIS)

    Tokuda, S.; Yoshino, R.; Matsumoto, T.; Hudson, S.R.; Kawano, Y.; Takizuka, T.

    2001-01-01

    Simulations have demonstrated that magnetic islands having the widths expected on the major disruption cause the collisionless loss of the relativistic electrons, and that the resultant loss rate is high enough to avoid or to suppress the runaway generation. It is because, for the magnetic fluctuations in the disruption, the loss of the electron confinement due to the breakdown of the toroidal momentum conservation overwhelms the runaway electron confinement due to the phase-averaging effect of relativistic electrons. Simulation results agree closely with recent experiments on fast plasma shutdown, showing that it is possible to prevent the generation of runaway electrons. (author)

  7. Space shuttle charging or beam-plasma discharge: What can electron spectrometer observations contribute to solving the question?

    International Nuclear Information System (INIS)

    Watermann, J.; Wilhelm, K.; Torkar, K.M.; Riedler, W.

    1988-01-01

    Several cooperative plasma experiments were carried out on board Spacelab-1, the ninth payload of the Space Transportation System (STS-9). Among them, the electron spectrometer 1ES019A was designed to observe 01.-12.5 keV electron fluxes with high temporal and spatial resolution, while the SEPAC electron beam accelerator emitted electron beams with currents up to 280 mA and maximum energies of 5 keV. Since the question of orbiter charging to high voltages has controversially been discussed in several publications on STS-3 and STS-9 electron beam experiments, an attempt is made to relate information from the return electron flux observed during the SEPAC operations to the vehicle charging interpretation. A close examination reveals that most of our observations can be understood if the occurrence of a beam-plasma discharge is assumed at least for electron beam intensities above 100 mA. This would provide a substantial return current capability. High orbiter charging effects during electron beam accelerator electron emissions are consequently not supported by the observations

  8. Electronic and magnetic properties of intermetallic compound YCo5

    International Nuclear Information System (INIS)

    Zhang, G.W.; Feng, Y.P.; Ong, C.K.

    1998-01-01

    The electronic and magnetic properties of the intermetallic compound YCo 5 have been studied using density functional theory with the local spin density approximation. The calculated magnetic moments of Y, Co(2c) and Co(3g) are -0.61, 1.68 and 2.04 μ B , respectively, and the total magnetic moment is about 8.87 μ B per formula unit, which agrees well with the previous experimental results. The dependence of the magnetic moments of Y, Co(2c) and Co(3g) on the lattice spacing has been investigated. The local electronic structure of Y, Co(2c) and Co(3g) are discussed in detail. The local magnetic susceptibilities of Y, Co(2c) and Co(3g) are calculated. Based on our results, YCo 5 was found to have characteristic of a strong ferromagnet. (orig.)

  9. Effects of finite electron temperature on gradient drift instabilities in partially magnetized plasmas

    Science.gov (United States)

    Lakhin, V. P.; Ilgisonis, V. I.; Smolyakov, A. I.; Sorokina, E. A.; Marusov, N. A.

    2018-01-01

    The gradient-drift instabilities of partially magnetized plasmas in plasma devices with crossed electric and magnetic fields are investigated in the framework of the two-fluid model with finite electron temperature in an inhomogeneous magnetic field. The finite electron Larmor radius (FLR) effects are also included via the gyroviscosity tensor taking into account the magnetic field gradient. This model correctly describes the electron dynamics for k⊥ρe>1 in the sense of Padé approximants (here, k⊥ and ρe are the wavenumber perpendicular to the magnetic field and the electron Larmor radius, respectively). The local dispersion relation for electrostatic plasma perturbations with the frequency in the range between the ion and electron cyclotron frequencies and propagating strictly perpendicular to the magnetic field is derived. The dispersion relation includes the effects of the equilibrium E ×B electron current, finite ion velocity, electron inertia, electron FLR, magnetic field gradients, and Debye length effects. The necessary and sufficient condition of stability is derived, and the stability boundary is found. It is shown that, in general, the electron inertia and FLR effects stabilize the short-wavelength perturbations. In some cases, such effects completely suppress the high-frequency short-wavelength modes so that only the long-wavelength low-frequency (with respect to the lower-hybrid frequency) modes remain unstable.

  10. Particle Acceleration and Magnetic Field Generation in Electron-Positron Relativistic Shocks

    Science.gov (United States)

    Nishikawa, K.-I.; Hardee, P.; Richardson, G.; Preece, R.; Sol, H.; Fishman, G. J.

    2005-01-01

    Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., Buneman, Weibel, and other two-stream instabilities) created in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a three-dimensional relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic electron-positron jet front propagating into an ambient electron-positron plasma with and without initial magnetic fields. We find small differences in the results for no ambient and modest ambient magnetic fields. New simulations show that the Weibel instability created in the collisionless shock front accelerates jet and ambient particles both perpendicular and parallel to the jet propagation direction. Furthermore, the nonlinear fluctuation amplitudes of densities, currents, and electric and magnetic fields in the electron-positron shock are larger than those found in the electron-ion shock studied in a previous paper at a comparable simulation time. This comes from the fact that both electrons and positrons contribute to generation of the Weibel instability. In addition, we have performed simulations with different electron skin depths. We find that growth times scale inversely with the plasma frequency, and the sizes of structures created by tine Weibel instability scale proportionally to the electron skin depth. This is the expected result and indicates that the simulations have sufficient grid resolution. While some Fermi acceleration may occur at the jet front, the majority of electron and positron acceleration takes place behind the jet front and cannot be characterized as Fermi acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying nonuniform, small-scale magnetic fields, which contribute to the electron s (positron s) transverse deflection behind the jet head. This

  11. Energy-loss magnetic chiral dichroism (EMCD): magnetic chiral dichroism in the electron microscope

    Czech Academy of Sciences Publication Activity Database

    Rubino, S.; Schattschneider, P.; Stöger-Pollach, M.; Hébert, S.; Rusz, Ján; Calmels, L.; Warot-Fonrose, B.; Houdellier, F.; Serin, V.; Novák, Pavel

    2008-01-01

    Roč. 23, č. 10 (2008), s. 2582-2590 ISSN 0884-2914 EU Projects: European Commission(XE) 508971 - CHIRALTEM Institutional research plan: CEZ:AV0Z10100521 Keywords : magnetic circular dichroism * transmission electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.743, year: 2008

  12. Calibration of the OHREX high-resolution imaging crystal spectrometer at the Livermore electron beam ion traps

    Energy Technology Data Exchange (ETDEWEB)

    Hell, N. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Dr. Remeis-Sternwarte and ECAP, Universität Erlangen-Nürnberg, Bamberg 96049 (Germany); Beiersdorfer, P.; Magee, E. W.; Brown, G. V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2016-11-15

    We report the calibration of the Orion High-Resolution X-ray (OHREX) imaging crystal spectrometer at the EBIT-I electron beam ion trap at Livermore. Two such instruments, dubbed OHREX-1 and OHREX-2, are fielded for plasma diagnostics at the Orion laser facility in the United Kingdom. The OHREX spectrometer can simultaneously house two spherically bent crystals with a radius of curvature of r = 67.2 cm. The focusing properties of the spectrometer allow both for larger distance to the source due to the increase in collected light and for observation of extended sources. OHREX is designed to cover a 2.5°–3° spectral range at Bragg angles around 51.3°. The typically high resolving powers at these large Bragg angles are ideally suited for line shape diagnostics. For instance, the nominal resolving power of the instrument (>10 000) is much higher than the effective resolving power associated with the Doppler broadening due to the temperature of the trapped ions in EBIT-I. The effective resolving power is only around 3000 at typical EBIT-I conditions, which nevertheless is sufficient to set up and test the instrument’s spectral characteristics. We have calibrated the spectral range for a number of crystals using well known reference lines in the first and second order and derived the ion temperatures from these lines. We have also made use of the 50 μm size of the EBIT-I source width to characterize the spatial focusing of the spectrometer.

  13. Electron temperatures within magnetic clouds between 2 and 4 AU: Voyager 2 observations

    Science.gov (United States)

    Sittler, E. C.; Burlaga, L. F.

    1998-08-01

    We have performed an analysis of Voyager 2 plasma electron observations within magnetic clouds between 2 and 4 AU identified by Burlaga and Behannon [1982]. The analysis has been confined to three of the magnetic clouds identified by Burlaga and Behannon that had high-quality data. The general properties of the plasma electrons within a magnetic cloud are that (1) the moment electron temperature anticorrelates with the electron density within the cloud, (2) the ratio Te/Tp tends to be >1, and (3) on average, Te/Tp~7.0. All three results are consistent with previous electron observations within magnetic clouds. Detailed analyses of the core and halo populations within the magnetic clouds show no evidence of either an anticorrelation between the core temperature TC and the electron density Ne or an anticorrelation between the halo temperature TH and the electron density. Within the magnetic clouds the halo component can contribute more than 50% of the electron pressure. The anticorrelation of Te relative to Ne can be traced to the density of the halo component relative to the density of the core component. The core electrons dominate the electron density. When the density goes up, the halo electrons contribute less to the electron pressure, so we get a lower Te. When the electron density goes down, the halo electrons contribute more to the electron pressure, and Te goes up. We find a relation between the electron pressure and density of the form Pe=αNeγ with γ~0.5.

  14. An efficient digital phase sensitive detector for use in electron spin resonance spectroscopy

    International Nuclear Information System (INIS)

    Vistnes, A.I; Wormald, D.I.; Isachsen, S.

    1983-10-01

    A digital sensitive detector for a modified Bruker electron spin resonance spectrometer, equipped with an Aspect 2000 minicomputer, is described. Magnetic field modulation is derived from a clock in the computer, which makes it possible to perform the data acquisition fully synchronously with the modulation. The resulting high phase accuracy makes it possible to compress the data to a single modulation period before the Fourier transformation. Both the in-phase and the phase-quadrature signals (of the first or second harmonic) are recorded simultaneously. The system makes the data processing, including the Fourier transformation, approximately 1000 times faster than previously reported digital phase sensitive detector systems for electron spin resonance spectrometers

  15. Effect of nonthermal electrons on oblique electrostatic excitations in a magnetized electron-positron-ion plasma

    Energy Technology Data Exchange (ETDEWEB)

    Alinejad, H. [Department of Physics, Faculty of Basic Science, Babol University of Technology, Babol 47148-71167 (Iran, Islamic Republic of)

    2012-05-15

    The linear and nonlinear propagation of ion-acoustic waves are investigated in a magnetized electron-positron-ion (e-p-i) plasma with nonthermal electrons. In the linear regime, the propagation of two possible modes and their evolution are studied via a dispersion relation. In the cases of parallel and perpendicular propagation, it is shown that these two possible modes are always stable. Then, the Korteweg-de Vries equation describing the dynamics of ion-acoustic solitary waves is derived from a weakly nonlinear analysis. The influence on the solitary wave characteristics of relevant physical parameters such as nonthermal electrons, magnetic field, obliqueness, positron concentration, and temperature ratio is examined. It is observed that the increasing nonthermal electrons parameter makes the solitary structures much taller and narrower. Also, it is revealed that the magnetic field strength makes the solitary waves more spiky. The present investigation contributes to the physics of the nonlinear electrostatic ion-acoustic waves in space and laboratory e-p-i plasmas in which wave damping produces an electron tail.

  16. Tailoring of electron flow current in magnetically insulated transmission lines

    Directory of Open Access Journals (Sweden)

    J. P. Martin

    2009-03-01

    Full Text Available It is desirable to optimize (minimizing both the inductance and electron flow the magnetically insulated vacuum sections of low impedance pulsed-power drivers. The goal of low inductance is understandable from basic efficiency arguments. The goal of low electron flow results from two observations: (1 flowing electrons generally do not deliver energy to (or even reach most loads, and thus constitute a loss mechanism; (2 energetic electrons deposited in a small area can cause anode damage and anode plasma formation. Low inductance and low electron flow are competing goals; an optimized system requires a balance of the two. While magnetically insulated systems are generally forgiving, there are times when optimization is crucial. For example, in large pulsed-power drivers used to energize high energy density physics loads, the electron flow as a fraction of total current is small, but that flow often reaches the anode in relatively small regions. If the anode temperature becomes high enough to desorb gas, the resulting plasma initiates a gap closure process that can impact system performance. Magnetic-pressure driven (z pinches and material equation of state loads behave like a fixed inductor for much of the drive pulse. It is clear that neither fixed gap nor constant-impedance transmission lines are optimal for driving inductive loads. This work shows a technique for developing the optimal impedance profile for the magnetically insulated section of a high-current driver. Particle-in-cell calculations are used to validate the impedance profiles developed in a radial disk magnetically insulated transmission line geometry. The input parameters are the spacing and location of the minimum gap, the effective load inductance, and the desired electron flow profile. The radial electron flow profiles from these simulations are in good agreement with theoretical predictions when driven at relatively high voltage (i.e., V≥2  MV.

  17. Momentum mapping spectrometer for probing the fragmentation dynamics of molecules induced by keV electrons

    International Nuclear Information System (INIS)

    Singh, Raj; Bhatt, Pragya; Yadav, Namita; Shanker, R

    2011-01-01

    We describe a new experimental setup for studying the fragmentation dynamics of molecules induced by the impact of keV electrons using the well-known technique of recoil ion momentum spectroscopy. The apparatus consists of mainly a time- and position-sensitive multi-hit particle detector for ion analysis and a channel electron multiplier detector for detecting the ejected electrons. Different components of the setup and the relevant electronics for data acquisition are described in detail with their working principles. In order to verify the reliable performance of the setup, we have recorded the collision-induced ionic spectra of the CO 2 molecule by the impact of keV electrons. Information about the ion pairs of CO + :O + , C + :O + and O + :O + resulting from dissociative ionizing collisions of 20 and 26 keV electrons with a dilute gaseous target of CO 2 molecules has been obtained. Under conditions of the present experiment, the momentum resolutions of the spectrometer for the combined momenta of CO + and O + ions in the direction of the time-of-flight axis and perpendicular to the direction of an electron beam are found to be 10.0 ± 0.2 and 15.0 ± 0.3 au, respectively

  18. Measurement of the magnetic interaction between two bound electrons of two separate ions.

    Science.gov (United States)

    Kotler, Shlomi; Akerman, Nitzan; Navon, Nir; Glickman, Yinnon; Ozeri, Roee

    2014-06-19

    Electrons have an intrinsic, indivisible, magnetic dipole aligned with their internal angular momentum (spin). The magnetic interaction between two electronic spins can therefore impose a change in their orientation. Similar dipolar magnetic interactions exist between other spin systems and have been studied experimentally. Examples include the interaction between an electron and its nucleus and the interaction between several multi-electron spin complexes. The challenge in observing such interactions for two electrons is twofold. First, at the atomic scale, where the coupling is relatively large, it is often dominated by the much larger Coulomb exchange counterpart. Second, on scales that are substantially larger than the atomic, the magnetic coupling is very weak and can be well below the ambient magnetic noise. Here we report the measurement of the magnetic interaction between the two ground-state spin-1/2 valence electrons of two (88)Sr(+) ions, co-trapped in an electric Paul trap. We varied the ion separation, d, between 2.18 and 2.76 micrometres and measured the electrons' weak, millihertz-scale, magnetic interaction as a function of distance, in the presence of magnetic noise that was six orders of magnitude larger than the magnetic fields the electrons apply on each other. The cooperative spin dynamics was kept coherent for 15 seconds, during which spin entanglement was generated, as verified by a negative measured value of -0.16 for the swap entanglement witness. The sensitivity necessary for this measurement was provided by restricting the spin evolution to a decoherence-free subspace that is immune to collective magnetic field noise. Our measurements show a d(-3.0(4)) distance dependence for the coupling, consistent with the inverse-cube law.

  19. Calibration of imaging plates to electrons between 40 and 180 MeV

    International Nuclear Information System (INIS)

    Rabhi, N.; Batani, D.; Boutoux, G.; Ducret, J.-E.; Bohacek, K.; Guillaume, E.; Thaury, C.; Jakubowska, K.; Thfoin, I.

    2016-01-01

    This paper presents the response calibration of Imaging Plates (IPs) for electrons in the 40-180 MeV range using laser-accelerated electrons at Laboratoire d’Optique Appliquée (LOA), Palaiseau, France. In the calibration process, the energy spectrum and charge of electron beams are measured by an independent system composed of a magnetic spectrometer and a Lanex scintillator screen used as a calibrated reference detector. It is possible to insert IPs of different types or stacks of IPs in this spectrometer in order to detect dispersed electrons simultaneously. The response values are inferred from the signal on the IPs, due to an appropriate charge calibration of the reference detector. The effect of thin layers of tungsten in front and/or behind IPs is studied in detail. GEANT4 simulations are used in order to analyze our measurements.

  20. Magnetic electron lenses

    CERN Document Server

    1982-01-01

    No single volume has been entirely devoted to the properties of magnetic lenses, so far as I am aware, although of course all the numerous textbooks on electron optics devote space to them. The absence of such a volume, bringing together in­ formation about the theory and practical design of these lenses, is surprising, for their introduction some fifty years ago has created an entirely new family of commercial instruments, ranging from the now traditional transmission electron microscope, through the reflection and transmission scanning microscopes, to co­ lumns for micromachining and microlithography, not to mention the host of experi­ mental devices not available commercially. It therefore seemed useful to prepare an account of the various aspects of mag­ netic lens studies. These divide naturally into the five chapters of this book: the theoretical background, in which the optical behaviour is described and formu­ lae given for the various aberration coefficients; numerical methods for calculat­ ing...

  1. High temperature electrons exhausted from rf plasma sources along a magnetic nozzle

    Science.gov (United States)

    Takahashi, Kazunori; Akahoshi, Hikaru; Charles, Christine; Boswell, Rod W.; Ando, Akira

    2017-08-01

    Two dimensional profiles of electron temperature are measured inside and downstream of a radiofrequency plasma thruster source having a magnetic nozzle and being immersed in vacuum. The temperature is estimated from the slope of the fully swept I-V characteristics of a Langmuir probe acquired at each spatial position and with the assumption of a Maxwellian distribution. The results show that the peripheral high temperature electrons in the magnetic nozzle originate from the upstream antenna location and are transported along the "connecting" magnetic field lines. Two-dimensional measurements of electron energy probability functions are also carried out in a second simplified laboratory device consisting of the source contiguously connected to the diffusion chamber: again the high temperature electrons are detected along the magnetic field lines intersecting the wall at the antenna location, even when the antenna location is shifted along the main axis. These results demonstrate that the peripheral energetic electrons in the magnetic nozzle mirror those created in the source tube.

  2. Device for irradiation with electron and a magnetic lens for deviation of beams of charged particles, especially electrons

    International Nuclear Information System (INIS)

    Anderberg, B.

    1990-01-01

    An electron beam is sweeping aver the object while this is moved forward. In order to achieve a uniform irradiation and compensate for geometric errors, an additional magnetic lens is located immediately beneath the exposed area. The magnetic lens refract the electron beam in such a manner that the particle trajectories become parallel or slightly convergent after the lens. The lens consists of two parallel permanent bar magnets, preferably laminated magnets. (L.F.)

  3. Local secondary-electron emission spectra of graphite and gold surfaces obtained using the Scanning Probe Energy Loss Spectrometer (SPELS)

    International Nuclear Information System (INIS)

    Lawton, J J; Pulisciano, A; Palmer, R E

    2009-01-01

    Secondary-electron emission (SEE) spectra have been obtained with the Scanning Probe Energy Loss Spectrometer at a tip-sample distance of only 50 nm. Such short working distances are required for the best theoretical spatial resolution (<10 nm). The SEE spectra of graphite, obtained as a function of tip bias voltage, are shown to correspond to unoccupied states in the electronic band structure. The SEE spectra of thin gold films demonstrate the capability of identifying (carbonaceous) surface contamination with this technique.

  4. Local secondary-electron emission spectra of graphite and gold surfaces obtained using the Scanning Probe Energy Loss Spectrometer (SPELS)

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, J J; Pulisciano, A; Palmer, R E, E-mail: R.E.Palmer@bham.ac.u [Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2009-11-25

    Secondary-electron emission (SEE) spectra have been obtained with the Scanning Probe Energy Loss Spectrometer at a tip-sample distance of only 50 nm. Such short working distances are required for the best theoretical spatial resolution (<10 nm). The SEE spectra of graphite, obtained as a function of tip bias voltage, are shown to correspond to unoccupied states in the electronic band structure. The SEE spectra of thin gold films demonstrate the capability of identifying (carbonaceous) surface contamination with this technique.

  5. Magnetic Electron Filtering by Fluid Models for the PEGASES Thruster

    Science.gov (United States)

    Leray, Gary; Chabert, Pascal; Lichtenberg, Allan; Lieberman, Michael

    2009-10-01

    The PEGASES thruster produces thrust by creating positive and negative ions, which are then accelerated. To accelerate both type of ions, electrons need to be filtered, which is achieved by applying a static magnetic field strong enough to magnetize the electrons but not the ions. A 1D fluid model with three species (electrons, positive and negative ions) and an analytical model are proposed to understand this process for an oxygen plasma with p = 10 mTorr and B0 = 300 G [1]. The resulting ion-ion plasma formation in the transverse direction (perpendicular to the magnetic field) is demonstrated. It is shown that an additional electron/positive ion loss term is required. The solutions are evaluated for two main parameters: the ionizing fraction at the plasma center (x = 0), ne0/ng, and the electronegativity ratio at the center, α0=nn0/ne0. The effect of geometry and magnetic field amplitude are also discussed. [4pt] [1] Leray G, Chabert P, Lichtenberg A J and Lieberman M A, J. Phys. D: Appl. Phys., Plasma Modelling Cluster issue, to appear (2009)

  6. Self-consistent electronic structure of spin-polarized dilute magnetic semiconductor quantum wells

    International Nuclear Information System (INIS)

    Hong, S. P.; Yi, K. S.; Quinn, J. J.

    2000-01-01

    The electronic properties of spin-symmetry-broken dilute magnetic semiconductor quantum wells are investigated self-consistently at zero temperature. The spin-split subband structure and carrier concentration of modulation-doped quantum wells are examined in the presence of a strong magnetic field. The effects of exchange and correlations of electrons are included in a local-spin-density-functional approximation. We demonstrate that exchange correlation of electrons decreases the spin-split subband energy but enhances the carrier density in a spin-polarized quantum well. We also observe that as the magnetic field increases, the concentration of spin-down (majority) electrons increases but that of spin-up (minority) electrons decreases. The effect of orbital quantization on the in-plane motion of electrons is also examined and shows a sawtoothlike variation in subband electron concentrations as the magnetic-field intensity increases. The latter variation is attributed to the presence of ionized donors acting as the electron reservoir, which is partially responsible for the formation of the integer quantum Hall plateaus. (c) 2000 The American Physical Society

  7. Injection, compression and confinement of electrons in a magnetic mirror

    International Nuclear Information System (INIS)

    Fisher, A.

    1975-01-01

    A Helmholtz coil configuration has been constructed where the magnetic field can be increased to about 10 kGauss in 20 μsec. Electrons are injected from a hot tantalum filament between two plates across which a potential of about 5 keV is applied. The electric field E is perpendicular to the magnetic field B so that the direction of the E x B drift is radial--into the magnetic mirror. About 10 14 electrons were injected and about 10 13 electrons were trapped. The initial electron energy was about 5 keV and after compression 500 keV x-rays were observed. The confinement time is very sensitive to vacuum. Confinement times of milliseconds and good compression were observed at vacuum of 5.10 -5 torr or less. Above 5.10 -5 torr there was no trapping or compression. After a compressed ring of electrons was formed, it was released by a pulse applied to one of the Helmholtz coils that reduced the field. Ejection of the electron ring was observed by x-ray measurements

  8. The magnetic spectrometer PAMELA for the study of cosmic antimatter in space

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy)]|[INFN, Rome (Italy); Hof, M. [Siegen univ. (Germany). Fachbereich Physik; Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy); Bellotti, R.; Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy)

    1995-09-01

    In the framework of the RIM (Russian Italian mission) program, PAMELA is the experiment devoted to the accurate measurement of the positron and antiproton spectra from the very low energy thresh-old of 100 MeV up to more than 50 GeV, and to hunt antinuclei with sensitivity better than 10{sup -7} in the helium/helium ratio. A permanent magnet equipped by microstrip silicon sensors, measures the particle momentum with MDR=400 GV/c on GF=25 cm{sup 2} sr. An accurate ToF system, a 19 X{sub o} deep imaging calorimeter, an aerogel Cherenkov counter and a TRD detector complement the spectrometer in order an efficient e{sup +-}/p{sup +-} separation and some light isotope identification capability. The PAMELA experiment will be carried out on a 700 km high polar orbit, on board of the Earth-observation meteor-3A satellite, to be launched at the end of 1988.

  9. Energization of electrons in a plasma beam entering a curved magnetic field

    International Nuclear Information System (INIS)

    Brenning, N.; Lindberg, L.; Eriksson, A.

    1980-09-01

    Earlier experiments have indicated that suprathermal electrons appear when a collisionless plasma flowing along a magnetic field enters a region where the magnetic field is curved. In the present investigation newly developed methods of He-spectroscopy based on the absolute intensities of the He I 3889 A and He II 4686 A lines are utilized to study the electron temperature and to estimate the population of non-thermal electrons. The density of helium added for the diagnostic purpose is so low that the flow is not disturbed. It is found that the intrusion of the plasma into a curved or transverse field gives rise to a slight increase (15-20%) in the electron temperature and a remarkable increase in the fraction of non-thermal (>100 eV) electrons from below 1% to as much as 20-25% of the total electron population. There are also indications that the energization of electrons is particularly efficient on that side of the plasma beam which becomes polarized to a positive potential when entering the curved field. The experiments are confined to the case of weak magnetic field, i.e. only the electrons are magnetically confined. New details of the electric field and potential structure are presented and discussed. Electric field components parallel to the magnetic field are likely to energize the electrons, probably through the run-away phenomenon. (Auth.)

  10. Relativistic degenerate electron plasma in an intense magnetic field

    International Nuclear Information System (INIS)

    Delsante, A.E.; Frankel, N.E.

    1978-01-01

    The dielectric response function for a dense, ultra-degenerate relativistic electron plasma in an intense uniform magnetic field is presented. Dispersion relations for plasma oscillations parallel and perpendicular to the magnetic field are obtained

  11. Design, construction, and calibration of a nonfocusing neutron spectrometer

    International Nuclear Information System (INIS)

    Storey, W.

    1974-12-01

    A fourteen-channel time-resolved neutron spectrometer with associated Faraday cup has been designed and constructed for use in the field. A neutron energy range of 9.5 to 15 MeV is covered. Both instruments detect protons elastically scattered from a thin hydrogenous foil in interaction with the neutron beam, with magnetic analysis of the protons by the spectrometer. The design requirements of small size and weight and 0.6 to 0.7 MeV resolution have been met. Following a description of the instrument and of its geometry, there is a detailed presentation of the design and construction of the instrument. The section on instrument performance is concerned with the comparison between predicted performance based upon computation, in which the magnet is of primary interest, and upon measured performance based upon a calibration experiment, which is given a general description in Appendix A. Software used mainly for signal prediction and unfolding, for both the neutron spectrometer and Faraday cup, is described

  12. A novel rhombohedron-like nickel ferrite nanostructure: Microwave combustion synthesis, structural characterization and magnetic properties

    Directory of Open Access Journals (Sweden)

    G. Suresh Kumar

    2016-09-01

    Full Text Available Research on nickel ferrite nanostructures has drawn a great interest because of its inherent chemical, physical and electronic properties. In this study, we have synthesized rhombohedron – like nickel ferrite nanostructure by a rapid microwave assisted combustion method using ethylenediamminetetraacetic acid as a chelating agent. X-ray diffraction, Fourier transform infrared spectrometer, transmission electron microscope and energy dispersive X-ray microanalyser were used to characterize the prepared sample. The magnetic behaviour was analysed by means of field dependent magnetization measurement which indicates that the prepared sample exhibits a soft ferromagnetic nature with saturation magnetization of 63.034 emu/g. This technique can be a potential method to synthesize novel nickel ferrite nanostructure with improved magnetic properties.

  13. Electric-field effects on electronic tunneling transport in magnetic barrier structures

    International Nuclear Information System (INIS)

    Guo Yong; Wang Hao; Gu Binglin; Kawazoe, Yoshiyuki

    2000-01-01

    Electronic transport properties in magnetic barrier structures under the influence of an electric field have been investigated. The results indicate that the characteristics of transmission resonance are determined not only by the structure and the incident wave vector but also strongly by the electric field. It is shown that the transmission coefficient at resonance in the low-energy range is suppressed by applying the electric field for electron tunneling through the magnetic barrier structure, arranged with identical magnetic barriers and wells. It is also shown that the transmission resonance is first enhanced up to optimal resonance, and then suppressed with further increased electric field for electron tunneling through the magnetic barrier structure, arranged with unidentical building blocks. Strong suppression of the current density is also found in the magnetic barrier structure, arranged with two different building blocks

  14. Scattering of magnetized electrons at the boundary of low temperature plasmas

    Science.gov (United States)

    Krüger, Dennis; Trieschmann, Jan; Brinkmann, Ralf Peter

    2018-02-01

    Magnetized technological plasmas with magnetic fields of 10-200 mT, plasma densities of 1017-1019 m-3, gas pressures of less than 1 Pa, and electron energies from a few to (at most) a few hundred electron volts are characterized by electron Larmor radii r L, that are small compared to all other length scales of the system, including the spatial scale L of the magnetic field and the collisional mean free path λ. In this regime, the classical drift approximation applies. In the boundary sheath of these discharges, however, that approximation breaks down: The sheath penetration depth of electrons (a few to some ten Debye length λ D; depending on the kinetic energy; typically much smaller than the sheath thickness of tens/hundreds of λ D) is even smaller than r L. For a model description of the electron dynamics, an appropriate boundary condition for the plasma/sheath interface is required. To develop such, the interaction of magnetized electrons with the boundary sheath is investigated using a 3D kinetic single electron model that sets the larger scales L and λ to infinity, i.e. neglects magnetic field gradients, the electric field in the bulk, and collisions. A detailed comparison of the interaction for a Bohm sheath (which assumes a finite Debye length) and a hard wall model (representing the limit {λ }{{D}}\\to 0; also called the specular reflection model) is conducted. Both models are found to be in remarkable agreement with respect to the sheath-induced drift. It is concluded that the assumption of specular reflection can be used as a valid boundary condition for more realistic kinetic models of magnetized technological plasmas.

  15. New Electron Cloud Detectors for the PS Main Magnets

    CERN Document Server

    Yin Vallgren, Ch; Gilardoni, S; Taborelli, M; Neupert, H; Ferreira Somoza, J

    2014-01-01

    Electron cloud (EC) has already been observed during normal operation of the PS, therefore it is necessary to study its in fluence on any beam instability for the future LHC Injector Upgrade (LIU). Two new electron cloud detectors have been discussed, developed and installed during the Long Shutdown (LS1) in one of the PS main magnets. The first measurement method is based on current measurement by using a shielded button-type pick-up. Due to the geometry and space limitation in the PS magnet, the button-type pick-up made of a 96%Al2O3 block coated with a thin layer of solvent-based Ag painting, placed 30 degrees to the bottom part of the vacuum chamber was installed in the horizontal direction where the only opening of the magnet coil is. The other newly developed measurement method is based on detection of photons emitted by the electrons from the electron cloud impinging on the vacuum chamber walls. The emitted photons are reected to a quartz window. A MCP-PMT (Micro-Channel Plate Photomultiplier Tube) wit...

  16. Numerical methods in electron magnetic resonance

    International Nuclear Information System (INIS)

    Soernes, A.R.

    1998-01-01

    The focal point of the thesis is the development and use of numerical methods in the analysis, simulation and interpretation of Electron Magnetic Resonance experiments on free radicals in solids to uncover the structure, the dynamics and the environment of the system

  17. Numerical methods in electron magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Soernes, A.R

    1998-07-01

    The focal point of the thesis is the development and use of numerical methods in the analysis, simulation and interpretation of Electron Magnetic Resonance experiments on free radicals in solids to uncover the structure, the dynamics and the environment of the system.

  18. Electronic and magnetic properties of pristine and hydrogenated borophene nanoribbons

    Science.gov (United States)

    Meng, Fanchen; Chen, Xiangnan; Sun, Songsong; He, Jian

    2017-07-01

    The groundbreaking works in graphene and graphene nanoribbons (GNRs) over the past decade, and the very recent discovery of borophene naturally draw attention to the yet-to-be-explored borophene nanoribbons (BNRs). We herein report a density functional theory (DFT) study of the electronic and magnetic properties of BNRs. The foci are the impact of orientation (denoted as BxNRs and ByNRs with their respective periodic orientations along x- and y-axis), ribbon width (Nx, Ny=4-15), and hydrogenation effects on the geometric, electronic and magnetic properties of BNRs. We found that the anisotropic quasi-planar geometric structure of BNR and the edge states largely govern its electronic and magnetic properties. In particular, pristine ByNRs adopt a magnetic ground state, either anti-ferromagnetic (AFM) or ferromagnetic (FM) depending on the ribbon width, while pristine BxNRs are non-magnetic (NM). Upon hydrogenation, all BNRs exhibit NM. Interestingly, both pristine and hydrogenated ByNRs undergo a metal-semiconductor-metal transition at Ny=7, while all BxNRs remain metallic.

  19. Determination of the Jet Neutron Rate and Fusion Power using the Magnetic Proton Recoil Neutron Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Sjoestrand, Henrik

    2003-01-01

    In this thesis a new independent method has been developed to enable precise measurements of neutron yields and rates from fusion plasmas and thereby determining the fusion power and fusion energy. The new method, together with the associated diagnostics, can provide information of great importance to present and future high fusion yield experiments, such as the Joint European Torus (JET) tokamak and the International Thermonuclear Experiment Reactor (ITER). The method has been applied to data from high fusion rate experiments from the tritium campaign at JET. By using the count-rate from the Magnetic Proton Recoil (MPR) neutron spectrometer the number of neutrons in the spectrometer's line of sight has been calculated. To be able to do this, all relevant factors between the plasma and the instrument have been evaluated. The number of neutrons in the MPR line of sight has been related to the total number of produced neutrons in the plasma by using information on the neutron emission profile. The achieved results have been compared with other JET neutron diagnostic data and the agreement is shown to be very good.

  20. Absolute sensitivity calibration from 20 A to 430 A of a grazing incidence spectrometer with a multi-element spectral detector

    International Nuclear Information System (INIS)

    Terry, J.L.; Manning, H.L.; Marmar, E.S.

    1986-07-01

    Two methods which together allow sensitivity calibration from 20 A to 430 A are described in detail. The first method, useful up to 120 A, uses a low power source to generate Kα x-rays which are alternately viewed by an absolute detector (a proportional counter) and the spectrometer. The second method extends that calibration to 430 A. It relies on the 2:1 brightness ratio of bright doublet lines from impurity ions which have a single outer shell electron and which are present in hot, magnetically confined plasmas. It requires that the absolute sensitivity of the spectrometer be known at one wavelength point, and in practice requires a multi-element spectral detector

  1. Electronic Structure Calculation of Permanent Magnets using the KKR Green's Function Method

    Science.gov (United States)

    Doi, Shotaro; Akai, Hisazumi

    2014-03-01

    Electronic structure and magnetic properties of permanent magnetic materials, especially Nd2Fe14B, are investigated theoretically using the KKR Green's function method. Important physical quantities in magnetism, such as magnetic moment, Curie temperature, and anisotropy constant, which are obtained from electronics structure calculations in both cases of atomic-sphere-approximation and full-potential treatment, are compared with past band structure calculations and experiments. The site preference of heavy rare-earth impurities are also evaluated through the calculation of formation energy with the use of coherent potential approximations. Further, the development of electronic structure calculation code using the screened KKR for large super-cells, which is aimed at studying the electronic structure of realistic microstructures (e.g. grain boundary phase), is introduced with some test calculations.

  2. ELECTRON TRAPPING IN WIGGLER AND QUADRUPOLE MAGNETS OF CESRTA

    International Nuclear Information System (INIS)

    Wang, Lanfa

    2010-01-01

    The Cornell Electron Storage Ring (CESR) has been reconfigured as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R and D (1). One of the primary goals of the CesrTA program is to investigate the interaction of the electron cloud with low emittance positron beam to explore methods to suppress the electron cloud, develop suitable advanced instrumentation required for these experimental studies and benchmark predictions by simulation codes. This paper reports the simulation of the electron-cloud formation in the wiggler and quadrupole magnets using the 3D code CLOUDLAND. We found that electrons can be trapped with long lifetime in a quadrupole magnet due to the mirror field trapping mechanism and photoelectrons produced in the wiggler zero field zone have long lifetime due to their complicated trajectory.

  3. Two-dimensional plasma expansion in a magnetic nozzle: Separation due to electron inertia

    International Nuclear Information System (INIS)

    Ahedo, Eduardo; Merino, Mario

    2012-01-01

    A previous axisymmetric model of the supersonic expansion of a collisionless, hot plasma in a divergent magnetic nozzle is extended here in order to include electron-inertia effects. Up to dominant order on all components of the electron velocity, electron momentum equations still reduce to three conservation laws. Electron inertia leads to outward electron separation from the magnetic streamtubes. The progressive plasma filling of the adjacent vacuum region is consistent with electron-inertia being part of finite electron Larmor radius effects, which increase downstream and eventually demagnetize the plasma. Current ambipolarity is not fulfilled and ion separation can be either outwards or inwards of magnetic streamtubes, depending on their magnetization. Electron separation penalizes slightly the plume efficiency and is larger for plasma beams injected with large pressure gradients. An alternative nonzero electron-inertia model [E. Hooper, J. Propul. Power 9, 757 (1993)] based on cold plasmas and current ambipolarity, which predicts inwards electron separation, is discussed critically. A possible competition of the gyroviscous force with electron-inertia effects is commented briefly.

  4. Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

    International Nuclear Information System (INIS)

    Molvik, A.W.; Kireeff Covo, M.; Cohen, R.; Coleman, J.; Sharp, W.; Bieniosek, F.; Friedman, A.; Roy, P.K.; Seidl, P.; Lund, S.M.; Faltens, A.; Vay, J.L.; Prost, L.

    2007-01-01

    The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam

  5. Electron correlation and magnetism: a perspective

    International Nuclear Information System (INIS)

    Mishra, S.G.

    1995-01-01

    In this article, a panoramic view of the results on the correlation effects in metals is presented. In the first two sections the scope of the subject of magnetism and talk about the necessity of inclusion of correlation in the free electron theory of metals is given. Then introduce some minimal models of correlation and magnetism in solids is discussed. Finally a brief perspective of some old and recent results on the Hubbard model are presented. Among the system described includes helium 3 high temperature superconductors. (author). 21 refs

  6. Simulation of loss electron in vacuum magnetically insulated transmission lines

    International Nuclear Information System (INIS)

    Zhang Pengfei; Li Yongdong; Liu Chunliang; Wang Hongguang; Guo Fan; Yang Hailiang; Qiu Aici; Su Zhaofeng; Sun Jianfeng; Sun Jiang; Gao Yi

    2011-01-01

    In the beginning of magnetic insulated period, loss electron in coaxial vacuum magnetically insulated transmission line (MITL) strikes anode and the bremsstrahlung photons are generated in the mean time. Based on the self-limited flow model, velocity in direction of energy transport, energy spectrum and angular distribution of loss electron are simulated by PIC code, energy spectrum of bremsstrahlung photons as well calculated though Monte Carlo method. Computational results show that the velocity of loss electron is less than 2.998 x 108 m/s, the angular excursion of electron is not much in a board extent of energy spectrum. These results show an indirect diagnosis of vacuum insulted transmission line working status based on loss electron bremsstrahlung. (authors)

  7. Magnetic Field Generation and Electron Acceleration in Relativistic Laser Channel

    International Nuclear Information System (INIS)

    Kostyukov, I.Yu.; Shvets, G.; Fisch, N.J.; Rax, J.M.

    2001-01-01

    The interaction between energetic electrons and a circularly polarized laser pulse inside an ion channel is studied. Laser radiation can be resonantly absorbed by electrons executing betatron oscillations in the ion channel and absorbing angular momentum from the laser. The absorbed angular momentum manifests itself as a strong axial magnetic field (inverse Faraday effect). The magnitude of this magnetic field is calculated and related to the amount of the absorbed energy. Absorbed energy and generated magnetic field are estimated for the small and large energy gain regimes. Qualitative comparisons with recent experiments are also made

  8. Mass-spectrometer of knock-on nuclei for reactor 'Pik'

    International Nuclear Information System (INIS)

    Begzhanov, P.B.; Nazarov, A.G.; Petrov, G.A.; Pikul', V.P.

    1999-01-01

    For reactor 'Pik' (that is being built in St. Petersburg Institute of Nuclear Physics) there was designed a universal two shoulder mass-spectrometer for non-decelerated fission products (FP) of nuclei. The spectrometer helps to obtain different values of linear magnification, dispersion, aberration coefficients and transmission without making structural changes in the device. To separate FP for one shoulder of spectrometer we chose ion-optical scheme (IOS) consisting of three electrostatic analyzers and three-sectional magnet 'JOSEF' that had high dispersion by masses at small deflection radius. IOS calculations of mass-spectrometer were performed with the help of program TRANSVOL (transfer of phase volume) designed basing on TRIO program. The program allows calculating of complete IOS transmission with taking into account elements aperture and beam officering

  9. The thermal triple-axis-spectrometer EIGER at the continuous spallation source SINQ

    Energy Technology Data Exchange (ETDEWEB)

    Stuhr, U., E-mail: uwe.stuhr@psi.ch [Laboratory of Neutron Scattering and Imaging, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Roessli, B.; Gvasaliya, S. [Laboratory of Neutron Scattering and Imaging, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Rønnow, H.M. [Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Féderale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Filges, U.; Graf, D.; Bollhalder, A.; Hohl, D.; Bürge, R.; Schild, M.; Holitzner, L.; Kaegi, C.; Keller, P.; Mühlebach, T. [Laboratory for Scientific Development and Novel Materials, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland)

    2017-05-01

    EIGER is the new thermal triple-axis-spectrometer at the continuous spallation SINQ at PSI. The shielding of the monochromator consists only of non- or low magnetizable materials, which allows the use of strong magnetic fields with the instrument. This shielding reduces the high energy neutron contamination to a comparable level of thermal spectrometers at reactor sources. The instrument design, the performance and first results of the spectrometer are presented.

  10. New proposal of mechanical reinforcement structures to annular REBaCuO bulk magnet for compact and cryogen-free NMR spectrometer

    Science.gov (United States)

    Fujishiro, H.; Takahashi, K.; Naito, T.; Yanagi, Y.; Itoh, Y.; Nakamura, T.

    2018-07-01

    We have proposed new reinforcement structures using an aluminum alloy ring to the annular REBaCuO bulks applicable to compact and cryogen-free 400 MHz (9.4 T) nuclear magnetic resonance (NMR) spectrometer using a numerical simulation of mechanical stress. The thermal compressive stress, σθcool, which was applied to the annular bulks during cooling due to the difference of thermal expansion coefficient between bulk and aluminum alloy, became fairly enhanced at the surface of the uppermost bulk for the new reinforcement structures, compared to the conventional reinforcement with the same height as the annular bulk, in which the compressive σθcool value was reduced. During field-cooled magnetization (FCM), the electromagnetic hoop stress, σθFCM, became the maximum at the innermost edge of the uppermost ring bulk at intermediate time step. The actual total hoop stress, σθ (= σθcool + σθFCM), due to both cooling and FCM processes was also analyzed and the new ring structures are fairly effective to reduce the σθ value and became lower than the fracture strength of the bulk. The new reinforcement structures have a possibility to avoid the fracture of the bulks and to realize a 400 MHz NMR spectrometer.

  11. Fourier Imaging X-ray Spectrometer (FIXS) for the Argentinian, Scout-launched satelite de Aplicaciones Cienficas-1 (SAC-1)

    International Nuclear Information System (INIS)

    Dennis, B.R.; Crannell, C.J.; Desai, U.D.

    1988-01-01

    The Fourier Imaging X-ray Spectrometer (FIXS) is one of four instruments on SAC-1, the Argentinian satellite being proposed for launch by NASA on a Scout rocket in 1992/3. The FIXS is designed to provide solar flare images at X-ray energies between 5 and 35 keV. Observations will be made on arcsecond size scales and subsecond time scales of the processes that modify the electron spectrum and the thermal distribution in flaring magnetic structures

  12. Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides

    Science.gov (United States)

    Hackett, Timothy A.; Baldwin, D. J.; Paudyal, D.

    2017-11-01

    Theoretical understanding of interactions between localized and mobile electrons and the crystal environment in light lanthanides is important because of their key role in much needed magnetic anisotropy in permanent magnet materials that have a great impact in automobile and wind turbine applications. We report electronic, magnetic, and magnetocrystalline properties of these basic light lanthanide elements studied from advanced density functional theory (DFT) calculations. We find that the inclusion of onsite 4f electron correlation and spin orbit coupling within the full-potential band structure is needed to understand the unique magnetocrystalline properties of these light lanthanides. The onsite electron correlation, spin orbit coupling, and full potential for the asphericity of charge densities must be taken into account for the proper treatment of 4f states. We find the variation of total energy as a function of lattice constants that indicate multiple structural phases in Ce contrasting to a single stable structure obtained in other light lanthanides. The 4f orbital magnetic moments are partially quenched as a result of crystalline electric field splitting that leads to magnetocrystalline anisotropy. The charge density plots have similar asphericity and environment in Pr and Nd indicating similar magnetic anisotropy. However, Ce and Sm show completely different asphericity and environment as both orbital moments are significantly quenched. In addition, the Fermi surface structures exemplified in Nd indicate structural stability and unravel a cause of anisotropy. The calculated magnetocrystalline anisotropy energy (MAE) reveals competing c-axis and in-plane anisotropies, and also predicts possibilities of unusual structural deformations in light lanthanides. The uniaxial magnetic anisotropy is obtained in the double hexagonal closed pack structures of the most of the light lanthanides, however, the anisotropy is reduced or turned to planar in the low symmetry

  13. Electron Fermi acceleration in collapsing magnetic traps: Computational and analytical models

    International Nuclear Information System (INIS)

    Gisler, G.; Lemons, D.

    1990-01-01

    The authors consider the heating and acceleration of electrons trapped on magnetic field lines between approaching magnetic mirrors. Such a collapsing magnetic trap and consequent electron energization can occur whenever a curved (or straight) flux tube drifts into a relatively straight (or curved) perpendicular shock. The relativistic, three-dimensional, collisionless test particle simulations show that an initial thermal electron distribution is bulk heated while a few individual electrons are accelerated to many times their original energy before they escape the trap. Upstream field-aligned beams and downstream pancake distributions perpendicular to the field are predicted. In the appropriate limit the simulation results agree well with a nonrelativistic analytic model of the distribution of escaping electrons which is based on the first adiabatic invariant and energy conservation between collisions with the mirrors. Space science and astrophysical applications are discussed

  14. Nonlinear electron transport in magnetized laser plasmas

    International Nuclear Information System (INIS)

    Kho, T.H.; Haines, M.G.

    1986-01-01

    Electron transport in a magnetized plasma heated by inverse bremsstrahlung is studied numerically using a nonlinear Fokker--Planck model with self-consistent E and B fields. The numerical scheme is described. Nonlocal transport is found to alter many of the transport coefficients derived from linear transport theory, in particular, the Nernst and Righi--Leduc effects, in addition to the perpendicular heat flux q/sub perpendicular/, are substantially reduced near critical surface. The magnetic field, however, remains strongly coupled to the nonlinear q/sub perpendicular/ and, as has been found in hydrosimulations, convective amplification of the magnetic field occurs in the overdense plasma

  15. Experiments on the injection, confinement, and ejection of electron clouds in a magnetic mirror

    International Nuclear Information System (INIS)

    Eckhouse, S.; Fisher, A.; Rostoker, N.

    1978-01-01

    A cloud of (5 to 10 keV) electrons is injected into a magnetic mirror field. The magnetic field rises in 40--120 μsec to a maximum of 10 kG. Two methods of injection were tried: In the first, the injector is located at the mirror midplane and electrons are injected perpendicular to the magnetic field lines. In the second scheme, the injector is located near the mirror maximum. Up to about 10 11 electrons were trapped in both schemes with a mean kinetic energy of 0.3 MeV. Measured confinement time is limited only by the magnetic field decay time. The compressed electron cloud executes electrostatic oscillations. The frequency of the oscillation is proportional to the number of electrons trapped, and it is independent of the value of the magnetic field and the initial electron energy. The electron cloud was ejected along the mirror axis and properties of the ejected electron cloud were measured by x-ray pulses from bremstrahlung of electrons on the vacuum system wall and by collecting electrons on a Faraday cup

  16. Free-electron lasers with magnetized ion-wiggler

    International Nuclear Information System (INIS)

    Mehdian, H.; Jafari, S.; Hasanbeigi, A.; Ebrahimi, F.

    2009-01-01

    Significant progress has been made using laser ionized channels to guide electron beams in the ion focus regime in a free-electron laser. Propagation of an electron beam in the ion focusing regime (IFR) allows the beam to propagate without expanding from space-charge repulsion. The ninth-degree polynomial dispersion relation for electromagnetic and space-charge waves is derived analytically by solving the electron momentum transfer and wave equations. The variation of resonant frequencies and peak growth rates with axial magnetic field strength has been demonstrated. Substantial enhancement in peak growth rate is obtained as the axial field frequency approaches the gyroresonance frequency.

  17. Electronic structure and magnetic properties of the ThCo4B compound

    International Nuclear Information System (INIS)

    Benea, D.; Pop, V.; Isnard, O.

    2008-01-01

    Detailed theoretical investigations of the electronic and magnetic properties of the newly discovered ThCo 4 B compound have been performed. The influence of the local environment on the magnitude of the Co magnetic moments is discussed by comparing the magnetic and electronic properties in the ThCo 4 B, YCo 4 B and ThCo 5 systems. All theoretical investigations of the electronic and magnetic properties have been done using the Korringa-Kohn-Rostoker (KKR) band-structure method in the ferromagnetic state. Very good agreement of the calculated and the experimental magnetic moments is obtained. Larger exchange-splitting is observed on the 2c site which carries by far the largest magnetic moment. Comparison of the band structure calculation for ThCo 5 and ThCo 4 B reveals that the presence of boron in the Co 6i site environment induces a broadening of the electronic bands as well as a significant reduction of the exchange-splitting and a diminution of the DOS at the Fermi level. These differences are attributed to the hybridization of the boron electronic states to the cobalt 3d ones. The calculated magnetic moment is 1.94μ B /formula unit. A large difference on the magnetic moment magnitude of the two Co sites is observed since 1.30 and 0.27μ B /atom are calculated for the 2c and 6i sites, respectively. The orbital contribution is found to differ by almost an order of magnitude on both cobalt sites. The Co magnetic moment is much smaller in the ThCo 4 B than in the YCo 4 B or RCo 4 B (where R is a rare earth) isotypes evidencing the major role played by the Th-Co bands on the electronic properties

  18. Electron beam fabrication and characterization of high-resolution magnetic force microscopy tips

    Science.gov (United States)

    Rührig, M.; Porthun, S.; Lodder, J. C.; McVitie, S.; Heyderman, L. J.; Johnston, A. B.; Chapman, J. N.

    1996-03-01

    The stray field, magnetic microstructure, and switching behavior of high-resolution electron beam fabricated thin film tips for magnetic force microscopy (MFM) are investigated with different imaging modes in a transmission electron microscope (TEM). As the tiny smooth carbon needles covered with a thermally evaporated magnetic thin film are transparent to the electron energies used in these TEMs it is possible to observe both the external stray field emanating from the tips as well as their internal domain structure. The experiments confirm the basic features of electron beam fabricated thin film tips concluded from various MFM observations using these tips. Only a weak but highly concentrated stray field is observed emanating from the immediate apex region of the tip, consistent with their capability for high resolution. It also supports the negligible perturbation of the magnetization sample due to the tip stray field observed in MFM experiments. Investigation of the magnetization distributions within the tips, as well as preliminary magnetizing experiments, confirm a preferred single domain state of the high aspect ratio tips. To exclude artefacts of the observation techniques both nonmagnetic tips and those supporting different magnetization states are used for comparison.

  19. Generation of Electron Whistler Waves at the Mirror Mode Magnetic Holes: MMS Observations and PIC Simulation

    Science.gov (United States)

    Ahmadi, N.; Wilder, F. D.; Usanova, M.; Ergun, R.; Argall, M. R.; Goodrich, K.; Eriksson, S.; Germaschewski, K.; Torbert, R. B.; Lindqvist, P. A.; Le Contel, O.; Khotyaintsev, Y. V.; Strangeway, R. J.; Schwartz, S. J.; Giles, B. L.; Burch, J.

    2017-12-01

    The Magnetospheric Multiscale (MMS) mission observed electron whistler waves at the center and at the gradients of magnetic holes on the dayside magnetosheath. The magnetic holes are nonlinear mirror structures which are anti-correlated with particle density. We used expanding box Particle-in-cell simulations and produced the mirror instability magnetic holes. We show that the electron whistler waves can be generated at the gradients and the center of magnetic holes in our simulations which is in agreement with MMS observations. At the nonlinear regime of mirror instability, the proton and electron temperature anisotropy are anti-correlated with the magnetic hole. The plasma is unstable to electron whistler waves at the minimum of the magnetic field structures. In the saturation regime of mirror instability, when magnetic holes are dominant, electron temperature anisotropy develops at the edges of the magnetic holes and electrons become isotropic at the magnetic field minimum. We investigate the possible mechanism for enhancing the electron temperature anisotropy and analyze the electron pitch angle distributions and electron distribution functions in our simulations and compare it with MMS observations.

  20. Experimental Investigation of Electron Cloud Containment in a Nonuniform Magnetic Field

    Science.gov (United States)

    Eninger, J. E.

    1974-01-01

    Dense clouds of electrons were generated and studied in an axisymmetric, nonuniform magnetic field created by a short solenoid. The operation of the experiment was similar to that of a low-pressure (approximately 0.000001 Torr) magnetron discharge. Discharge current characteristics are presented as a function of pressure, magnetic field strength, voltage, and cathode end-plate location. The rotation of the electron cloud is determined from the frequency of diocotron waves. In the space charge saturated regime of operation, the cloud is found to rotate as a solid body with frequency close to V sub a/phi sub a where V sub a is the anode voltage and phi suba is the total magnetic flux. This result indicates that, in regions where electrons are present, the magnetic field lines are electrostatic equipotentials (E bar, B bar = 0). Equilibrium electron density distributions suggested by this conditions are integrated with respect to total ionizing power and are found consistent with measured discharge currents.

  1. Experimental investigation of electron cloud containment in a nonuniform magnetic field

    International Nuclear Information System (INIS)

    Eninger, J.E.

    1974-05-01

    Dense clouds of electrons were generated and studied in an axisymmetric, nonuniform magnetic field created by a short solenoid. The operation of the experiment was similar to that of a low-pressure (approximately 0.000001 torr) magnetron discharge. Discharge current characteristics are presented as a function of pressure, magnetic field strength, voltage, and cathode end-plate location. The rotation of the electron cloud is determined from the frequency of diocotron waves. In the space charge saturated regime of operation, the cloud is found to rotate as a solid body with frequency close to V/sub a/phi/sub a/ where V/sub a/ is the anode voltage and phi/sub a/ is the total magnetic flux. This result indicates that, in regions where electrons are present, the magnetic field lines are electrostatic equipotentials (E bar, B bar = 0). Equilibrium electron density distributions suggested by this condition are integrated with respect to total ionizing power and are found consistent with measured discharge currents. (U.S.)

  2. Experimental modelling of the dipole magnet for the electron storage ring DELSY

    CERN Document Server

    Meshkov, I N; Syresin, E M

    2003-01-01

    In the Joint Institute for Nuclear Research (Dubna) the project of Dubna Electron Synchrotron (DELSY) with an electron energy of 1.2 GeV is developed. The electron storage ring in the DELSY project is planned to be created on the basis of magnetic elements, which were used earlier in the storage ring AmPS (NIKHEF, Amsterdam). The optics of the ring is necessary to be changed, its perimeter to be reduced approximately in one and a half time, the energy of electrons to be increased. The paper is devoted to the development of a modified dipole magnet of the storage ring. The preliminary estimation of geometry of the magnet pole is carried out by means of computer modelling using two- and three- dimensional codes of the magnetic field calculation SUPERFISH and RADIA. The experimental stand for the measurements of the dipole magnetic field is described. As the result of calculational and experimental modelling for the dipole magnet, the geometry of its poles was estimated, providing in the horizontal aperture +- 3...

  3. VEGAS: VErsatile GBT Astronomical Spectrometer

    Science.gov (United States)

    Bussa, Srikanth; VEGAS Development Team

    2012-01-01

    The National Science Foundation Advanced Technologies and Instrumentation (NSF-ATI) program is funding a new spectrometer backend for the Green Bank Telescope (GBT). This spectrometer is being built by the CICADA collaboration - collaboration between the National Radio Astronomy Observatory (NRAO) and the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California Berkeley.The backend is named as VErsatile GBT Astronomical Spectrometer (VEGAS) and will replace the capabilities of the existing spectrometers. This backend supports data processing from focal plane array systems. The spectrometer will be capable of processing up to 1.25 GHz bandwidth from 8 dual polarized beams or a bandwidth up to 10 GHz from a dual polarized beam.The spectrometer will be using 8-bit analog to digital converters (ADC), which gives a better dynamic range than existing GBT spectrometers. There will be 8 tunable digital sub-bands within the 1.25 GHz bandwidth, which will enhance the capability of simultaneous observation of multiple spectral transitions. The maximum spectral dump rate to disk will be about 0.5 msec. The vastly enhanced backend capabilities will support several science projects with the GBT. The projects include mapping temperature and density structure of molecular clouds; searches for organic molecules in the interstellar medium; determination of the fundamental constants of our evolving Universe; red-shifted spectral features from galaxies across cosmic time and survey for pulsars in the extreme gravitational environment of the Galactic Center.

  4. Iterative reconstruction of magnetic induction using Lorentz transmission electron tomography

    International Nuclear Information System (INIS)

    Phatak, C.; Gürsoy, D.

    2015-01-01

    Intense ongoing research on complex nanomagnetic structures requires a fundamental understanding of the 3D magnetization and the stray fields around the nano-objects. 3D visualization of such fields offers the best way to achieve this. Lorentz transmission electron microscopy provides a suitable combination of high resolution and ability to quantitatively visualize the magnetization vectors using phase retrieval methods. In this paper, we present a formalism to represent the magnetic phase shift of electrons as a Radon transform of the magnetic induction of the sample. Using this formalism, we then present the application of common tomographic methods particularly the iterative methods, to reconstruct the 3D components of the vector field. We present an analysis of the effect of missing wedge and the limited angular sampling as well as reconstruction of complex 3D magnetization in a nanowire using simulations. - Highlights: • We present a formalism to represent electron-optical magnetic phase shift as a Radon transform of the 3D magnetic induction of the nano-object. • We have analyzed four different tomographic reconstruction methods for vectorial data reconstruction. • Reconstruction methods were tested for varying experimental limitations such as limited tilt range and limited angular sampling. • The analysis showed that Gridrec and SIRT methods performed better with lower errors than other reconstruction methods

  5. Magnetic-field generation and electron-collimation analysis for propagating fast electron beams in overdense plasmas

    International Nuclear Information System (INIS)

    Cai Hongbo; Zhu Shaoping; Chen Mo; Wu Sizhong; He, X. T.; Mima, Kunioki

    2011-01-01

    An analytical fluid model is proposed for artificially collimating fast electron beams produced in the interaction of ultraintense laser pulses with specially engineered low-density-core-high-density-cladding structure targets. Since this theory clearly predicts the characteristics of the spontaneously generated magnetic field and its dependence on the plasma parameters of the targets transporting fast electrons, it is of substantial relevance to the target design for fast ignition. The theory also reveals that the rapid changing of the flow velocity of the background electrons in a transverse direction (perpendicular to the flow velocity) caused by the density jump dominates the generation of a spontaneous interface magnetic field for these kinds of targets. It is found that the spontaneously generated magnetic field reaches as high as 100 MG, which is large enough to collimate fast electron transport in overdense plasmas. This theory is also supported by numerical simulations performed using a two-dimensional particle-in-cell code. It is found that the simulation results agree well with the theoretical analysis.

  6. Studies of a hybrid avalanche photo-detector in magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Šantelj, L., E-mail: luka.santelj@kek.jp [High Energy Accelerator Research Organization (KEK) (Japan); Adachi, I. [High Energy Accelerator Research Organization (KEK) (Japan); Sokendai University (Japan); Hataya, K. [Tokyo Metropolitan University (Japan); Iori, S. [Toho University (Japan); Iwata, S.; Kakuno, H. [Tokyo Metropolitan University (Japan); Kataura, R. [Niigata University (Japan); Kawai, H. [Chiba University (Japan); Kindo, H. [Sokendai University (Japan); Korpar, S. [University of Maribor (Slovenia); Jožef Stefan Institute, Ljubljana (Slovenia); Križan, P. [Jožef Stefan Institute, Ljubljana (Slovenia); University of Ljubljana (Slovenia); Mrvar, M. [Jožef Stefan Institute, Ljubljana (Slovenia); Nath, K. [Indian Institute of Technology Guwahati (India); Nishida, S. [High Energy Accelerator Research Organization (KEK) (Japan); Sokendai University (Japan); Ogawa, S. [Niigata University (Japan); Pestotnik, R.; Stanovnik, A.; Seljak, A. [Jožef Stefan Institute, Ljubljana (Slovenia); Sumiyoshi, T. [Tokyo University of Science, Tokyo (Japan); Tabata, M. [Chiba University (Japan); and others

    2017-02-11

    For the Belle II spectrometer a proximity focusing RICH counter with an aerogel radiator (ARICH) will be employed as a PID system in the forward endcap region of the spectrometer. The main challenge was the development of a reliable multichannel sensor for single photons that operates in the high magnetic field of the spectrometer (1.5 T) and withstands the radiation levels expected at the experiment. A 144-channel Hybrid Avalanche Photo-Detector (HAPD) was developed with Hamamatsu Photonics K.K. and the mass production of ∼480 HAPDs was completed recently. While our first tests of HAPD performance in the magnetic field (before mass production) showed no issues, we lately observed a presence of very large signal pulses (∼5000× single photon signal), generated internally within about 20% of HAPDs, while operating in the magnetic field. The rate of these pulses varies from sample to sample. These pulses impact the HAPD performance in two ways: they introduce periods of dead time and, in some cases, damage to the front-end electronics was observed. Here we present conditions under which such large pulses are generated, their properties and impact on HAPD performance, and discuss possible mechanism of their origin.

  7. Electron holography study of magnetization behavior in the writer pole of a perpendicular magnetic recording head by a 1 MV transmission electron microscope.

    Science.gov (United States)

    Hirata, Kei; Ishida, Yoichi; Akashi, Tetsuya; Shindo, Daisuke; Tonomura, Akira

    2012-01-01

    The magnetic domain structure of the writer poles of perpendicular magnetic recording heads was studied using electron holography. Although the domain structure of a 100-nm-thick writer pole could be observed with a 300 kV transmission electron microscope, that of the 250-nm-thick writer pole could not be analyzed due to the limited transmission capability of the instrument. On the other hand, the detailed domain structure of the 250-nm-thick writer pole was successfully analyzed by a 1 MV electron microscope using its high transmission capability. The thickness and material dependency of the domain structure of a writer pole were discussed.

  8. An Airborne Infrared Spectrometer for Solar Eclipse Observations

    Science.gov (United States)

    Samra, Jenna; DeLuca, Edward E.; Golub, Leon; Cheimets, Peter; Philip, Judge

    2016-05-01

    The airborne infrared spectrometer (AIR-Spec) is an innovative solar spectrometer that will observe the 2017 solar eclipse from the NSF/NCAR High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER). AIR-Spec will image five infrared coronal emission lines to determine whether they may be useful probes of coronal magnetism.The solar magnetic field provides the free energy that controls coronal heating, structure, and dynamics. Energy stored in coronal magnetic fields is released in flares and coronal mass ejections and ultimately drives space weather. Therefore, direct coronal field measurements have significant potential to enhance understanding of coronal dynamics and improve solar forecasting models. Of particular interest are observations of field lines in the transitional region between closed and open flux systems, providing important information on the origin of the slow solar wind.While current instruments routinely observe only the photospheric and chromospheric magnetic fields, AIR-Spec will take a step toward the direct observation of coronal fields by measuring plasma emission in the infrared at high spatial and spectral resolution. During the total solar eclipse of 2017, AIR-Spec will observe five magnetically sensitive coronal emission lines between 1.4 and 4 µm from the HIAPER Gulfstream V at an altitude above 14.9 km. The instrument will measure emission line intensity, width, and Doppler shift, map the spatial distribution of infrared emitting plasma, and search for waves in the emission line velocities.AIR-Spec consists of an optical system (feed telescope, grating spectrometer, and infrared detector) and an image stabilization system, which uses a fast steering mirror to correct the line-of-sight for platform perturbations. To ensure that the instrument meets its research goals, both systems are undergoing extensive performance modeling and testing. These results are shown with reference to the science requirements.

  9. Contribution to the study of electron paramagnetic resonance and relaxation

    International Nuclear Information System (INIS)

    Theobald, Jean-Gerard

    1962-01-01

    This research thesis reports an experimental work which comprises the development of a very practical and very sensitive electron paramagnetic resonance spectrometer, and the use of this equipment for the study of irradiated substances and carbons. By studying electronic resonance signals by fast modulation of the magnetic field, the author studied phenomena of quick passage in electronic resonance, and showed that the study of these phenomena requires observation systems with a particularly large bandwidth. He reports the measurement of the line width of packs of spins of inhomogeneous lines by two different methods [fr

  10. Magnetic insulation of secondary electrons in plasma source ion implantation

    International Nuclear Information System (INIS)

    Rej, D.J.; Wood, B.P.; Faehl, R.J.; Fleischmann, H.H.

    1993-01-01

    The uncontrolled loss of accelerated secondary electrons in plasma source ion implantation (PSII) can significantly reduce system efficiency and poses a potential x-ray hazard. This loss might be reduced by a magnetic field applied near the workpiece. The concept of magnetically-insulated PSII is proposed, in which secondary electrons are trapped to form a virtual cathode layer near the workpiece surface where the local electric field is essentially eliminated. Subsequent electrons that are emitted can then be reabsorbed by the workpiece. Estimates of anomalous electron transport from microinstabilities are made. Insight into the process is gained with multi-dimensional particle-in-cell simulations

  11. Electronic structure and magnetic properties of Pd sub(3)Fe

    International Nuclear Information System (INIS)

    Kuhnen, C.A.

    1988-01-01

    In this work we study the electronic and magnetic properties of the Pd sub(3)Fe alloy. For the ordered phase of Pd sub(3)Fe we employed the Linear Muffin-Tin Orbitals Method, with the atomic sphere approximation, which is a first principles method and includes spin polarization. The theoretical results for the thermal and magnetic properties show good agreement with experience. Here we explain the formation of the localized magnetic moments from completely itinerant electrons. We investigate the influence of the hydrogen in the physical properties of the compound Pd sub(3)Fe, where we obtain a drastic reduction in the magnetic moments at the Pd and Fe sites. This reduction is confirmed by experience. The self consistent potentials of the Pd sub(3)Fe compound were used for an analysis of the influence of the disorder in the electronic structure of Pd sub(3)Fe alloy. To this end, we employ a spin polarized version of the Green's Function Method with the Coherent Potential Approximation (or KKR-CPA). The results obtained show that in random ferromagnetic alloys different degrees of disorder occurs for the different spin directions. The formation of the magnetic moments in these alloys were explained from the existence of 'virtual crystal' states for spin up electrons and 'split band' states for spin down electrons. Finally we employ the muffin-tin orbitals to calculate the X-ray photoemission spectra of the Pd sub(3)Fe and Pd sub(3)FeH compounds, which allows us a direct comparison between theory and experiment. (author)

  12. Adiabatic Expansion of Electron Gas in a Magnetic Nozzle

    Science.gov (United States)

    Takahashi, Kazunori; Charles, Christine; Boswell, Rod; Ando, Akira

    2018-01-01

    A specially constructed experiment shows the near perfect adiabatic expansion of an ideal electron gas resulting in a polytropic index greater than 1.4, approaching the adiabatic value of 5 /3 , when removing electric fields from the system, while the polytropic index close to unity is observed when the electrons are trapped by the electric fields. The measurements were made on collisionless electrons in an argon plasma expanding in a magnetic nozzle. The collision lengths of all electron collision processes are greater than the scale length of the expansion, meaning the system cannot be in thermodynamic equilibrium, yet thermodynamic concepts can be used, with caution, in explaining the results. In particular, a Lorentz force, created by inhomogeneities in the radial plasma density, does work on the expanding magnetic field, reducing the internal energy of the electron gas that behaves as an adiabatically expanding ideal gas.

  13. Spectrometer for shot-to-shot photon energy characterization in the multi-bunch mode of the free electron laser at Hamburg

    International Nuclear Information System (INIS)

    Palutke, S.; Wurth, W.; Gerken, N. C.; Mertens, K.; Klumpp, S.; Martins, M.; Mozzanica, A.; Schmitt, B.; Wunderer, C.; Graafsma, H.; Meiwes-Broer, K.-H.

    2015-01-01

    The setup and first results from commissioning of a fast online photon energy spectrometer for the vacuum ultraviolet free electron laser at Hamburg (FLASH) at DESY are presented. With the use of the latest advances in detector development, the presented spectrometer reaches readout frequencies up to 1 MHz. In this paper, we demonstrate the ability to record online photon energy spectra on a shot-to-shot base in the multi-bunch mode of FLASH. Clearly resolved shifts in the mean wavelength over the pulse train as well as shot-to-shot wavelength fluctuations arising from the statistical nature of the photon generating self-amplified spontaneous emission process have been observed. In addition to an online tool for beam calibration and photon diagnostics, the spectrometer enables the determination and selection of spectral data taken with a transparent experiment up front over the photon energy of every shot. This leads to higher spectral resolutions without the loss of efficiency or photon flux by using single-bunch mode or monochromators

  14. Electronics design of the RPC system for the OPERA muon

    International Nuclear Information System (INIS)

    Acquafredda, R.; Ambrosio, M.; Consiglio, L.

    2004-01-01

    The present document describes the front-end electronics of the RPC system that instruments the magnet muon spectrometer of the OPERA experiment. The main task of the OPERA spectrometer is to provide particle tracking information for muon identification and simplify the matching between the Precision Trackers. As no trigger has been foreseen for the experiment, the spectrometer electronics must be self-triggered with single-plane readout capability. Moreover, precision time information must be added within each event frame for off-line reconstruction. The read-out electronics is made of three different stages: the Front-End Boards (FEBs) system, the Controller Boards (CBs) system and Trigger Boards (TBs) system. The FEB system provides discrimination of the strip incoming signals; a FAST-OR output of the input signals is also available for trigger plane signal generation. FEB signals are required by the CB system that provides the zero suppression and manages the communication to the DAQ and Slow Control. A Trigger Board allows to operate in both self-trigger mode (the FEB's FAST-OR signal starts the plane acquisition) or in external-trigger mode (different conditions can be set on the FAST-OR signals generated from different planes)

  15. Improving the resolution in soft X-ray emission spectrometers through photon-counting using an Electron Multiplying CCD

    International Nuclear Information System (INIS)

    Hall, D J; Soman, M; Tutt, J; Murray, N; Holland, A; Schmitt, T; Raabe, J; Strocov, V N; Schmitt, B

    2012-01-01

    In 2007, a study of back-illuminated Charge-Coupled Devices (CCDs) for soft X-ray photon detection demonstrated the improvements that could be brought over more traditional micro-channel plate detectors for X-ray spectrometers based on diffraction gratings and position sensitive detectors. Whilst the spatial resolution was reported to be improved dramatically, an intrinsic limit of approximately 25 micrometers was found due to the spreading of the charge cloud generated in the CCD across several pixels. To overcome this resolution limit, it is necessary to move away from the current integrated imaging methods and consider a photon-counting approach, recording the photon interaction locations to the sub-pixel level. To make use of photon-counting techniques it is important that the individual events are separable. To maintain the throughput of the spectrometer for high intensity lines, higher frame rates and therefore higher readout speeds are required. With CCD based systems, the increased noise at high readout speeds can limit the photon-counting performance. The Electron-Multiplying CCD shares a similar architecture with the standard CCD but incorporates a g ain register . This novel addition allows controllable gain to be applied to the signal before the read noise is introduced, therefore allowing individual events to be resolved above the noise even at much higher readout rates. In the past, the EM-CCD has only been available with imaging areas too small to be practical in soft X-ray emission spectrometers. The current drive for large area Electron-Multiplying CCDs is opening this technology to new photon-counting applications, requiring in-depth analysis of the processes and techniques involved. Early results indicate that through the introduction of photon-counting techniques the resolution in such systems can be dramatically improved.

  16. Discovery of the radioactive decay of 223Ra by 14C emission and experiments with the magnetic spectrometer Soleno

    International Nuclear Information System (INIS)

    Hourani, E.; Hussonnois, M.

    1987-01-01

    The aim of this report is to review the experiment of Rose and Jones (discovery in 1984 of radioactive decay of 223 Ra by 14 C nuclei emission) with the subsequent one of Alexandrov (et al) performed with the same technique. The experiments performed by the group at Orsay on 14 C radioactivity of radium isotopes with the magnetic spectrometer Soleno are also reviewed. This review comprises the presentation and comments of the original results and arguments taken in their historical context

  17. Electronic band structure of magnetic bilayer graphene superlattices

    International Nuclear Information System (INIS)

    Pham, C. Huy; Nguyen, T. Thuong; Nguyen, V. Lien

    2014-01-01

    Electronic band structure of the bilayer graphene superlattices with δ-function magnetic barriers and zero average magnetic flux is studied within the four-band continuum model, using the transfer matrix method. The periodic magnetic potential effects on the zero-energy touching point between the lowest conduction and the highest valence minibands of pristine bilayer graphene are exactly analyzed. Magnetic potential is shown also to generate the finite-energy touching points between higher minibands at the edges of Brillouin zone. The positions of these points and the related dispersions are determined in the case of symmetric potentials.

  18. Electron cooling and finite potential drop in a magnetized plasma expansion

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Sanchez, M. [Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Navarro-Cavallé, J. [Escuela Técnica Superior de Ingeniería Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain); Ahedo, E. [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Avda. Universidad 30, Leganés 28911, Madrid (Spain)

    2015-05-15

    The steady, collisionless, slender flow of a magnetized plasma into a surrounding vacuum is considered. The ion component is modeled as mono-energetic, while electrons are assumed Maxwellian upstream. The magnetic field has a convergent-divergent geometry, and attention is restricted to its paraxial region, so that 2D and drift effects are ignored. By using the conservation of energy and magnetic moment of particles and the quasi-neutrality condition, the ambipolar electric field and the distribution functions of both species are calculated self-consistently, paying attention to the existence of effective potential barriers associated to magnetic mirroring. The solution is used to find the total potential drop for a set of upstream conditions, plus the axial evolution of various moments of interest (density, temperatures, and heat fluxes). The results illuminate the behavior of magnetic nozzles, plasma jets, and other configurations of interest, showing, in particular, in the divergent plasma the collisionless cooling of electrons, and the generation of collisionless electron heat fluxes.

  19. Analysis of magnetic electron lens with secant hyperbolic field distribution

    International Nuclear Information System (INIS)

    Pany, S.S.; Ahmed, Z.; Dubey, B.P.

    2014-01-01

    Electron-optical imaging instruments like Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) use specially designed solenoid electromagnets for focusing of the electron beam. Indicators of imaging performance of these instruments, like spatial resolution, have a strong correlation with the focal characteristics of the magnetic lenses, which in turn have been shown to be sensitive to the details of the spatial distribution of the axial magnetic field. Owing to the complexity of designing practical lenses, empirical mathematical expressions are important to obtain the desired focal properties. Thus the degree of accuracy of such models in representing the actual field distribution determines accuracy of the calculations and ultimately the performance of the lens. Historically, the mathematical models proposed by Glaser [1] and Ramberg [2] have been extensively used. In this paper the authors discuss another model with a secant-hyperbolic type magnetic field distribution function, and present a comparison between models, utilizing results from finite element-based field simulations as the reference for evaluating performance

  20. GHz nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Cross, T.A.; Drobny, G.; Trewhella, J.

    1994-12-01

    For the past dozen years, 500- and 600-MHz spectrometers have become available in many laboratories. The first 600-MHz NMR spectrometer (at Carnegie Mellon University) was commissioned more than 15 years ago and, until 1994, represented the highest field available for high-resolution NMR. This year, we have witnessed unprecedented progress in the development of very high field magnets for NMR spectroscopy, including the delivery of the first commercial 750-MHz NMR spectrometers. In addition, NMR signals have been obtained from 20-Tesla magnets (850 MHz for {sup 1}H`s) at both Los Alamos National Laboratory and Florida State University in the NHMFL (National High Magnetic Field Laboratory). These preliminary experiments have been performed in magnets with 100-ppm homogeneity, but a 20-Tesla magnet developed for the NHMFL will be brought to field this year with a projected homogeneity of 0.1 ppm over a 1-cm-diam spherical volume.

  1. Foucault imaging and small-angle electron diffraction in controlled external magnetic fields.

    Science.gov (United States)

    Nakajima, Hiroshi; Kotani, Atsuhiro; Harada, Ken; Ishii, Yui; Mori, Shigeo

    2016-12-01

    We report a method for acquiring Foucault images and small-angle electron diffraction patterns in external magnetic fields using a conventional transmission electron microscope without any modification. In the electron optical system that we have constructed, external magnetic fields parallel to the optical axis can be controlled using the objective lens pole piece under weak excitation conditions in the Foucault mode and the diffraction mode. We observe two ferromagnetic perovskite-type manganese oxides, La 0.7 Sr 0.3 MnO 3 (LSMO) and Nd 0.5 Sr 0.5 MnO 3 , in order to visualize magnetic domains and their magnetic responses to external magnetic fields. In rhombohedral-structured LSMO, pinning of magnetic domain walls at crystallographic twin boundaries was found to have a strong influence on the generation of new magnetic domains in external applied magnetic fields. © The Author 2016. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Localized Electron Heating by Strong Guide-Field Magnetic Reconnection

    Science.gov (United States)

    Guo, Xuehan; Sugawara, Takumichi; Inomoto, Michiaki; Yamasaki, Kotaro; Ono, Yasushi; UTST Team

    2015-11-01

    Localized electron heating of magnetic reconnection was studied under strong guide-field (typically Bt 15Bp) using two merging spherical tokamak plasmas in Univ. Tokyo Spherical Tokamak (UTST) experiment. Our new slide-type two-dimensional Thomson scattering system documented for the first time the electron heating localized around the X-point. The region of high electron temperature, which is perpendicular to the magnetic field, was found to have a round shape with radius of 2 [cm]. Also, it was localized around the X-point and does not agree with that of energy dissipation term Et .jt . When we include a guide-field effect term Bt / (Bp + αBt) for Et .jt where α =√{ (vin2 +vout2) /v∥2 } , the energy dissipation area becomes localized around the X-point, suggesting that the electrons are accelerated by the reconnection electric field parallel to the magnetic field and thermalized around the X-point. This work was supported by JSPS A3 Foresight Program ``Innovative Tokamak Plasma Startup and Current Drive in Spherical Torus,'' a Grant-in-Aid from the Japan Society for the Promotion of Science (JSPS) Fellows 15J03758.

  3. Theme of the Workshop on Itinerant-Electron Magnetism, and Spin Fluctuations

    Science.gov (United States)

    Yoshimura, Kazuyoshi

    2017-06-01

    The international workshop on itinerant-electron magnetism was held during September 25-27, 2015 in the seminar house of Graduate School of Science, Kyoto University, Kyoto, Japan. Here, I explain the theme of this workshop, and stress the development of itinerant-electron magnetism in several decades. The workshop was also organized in commemoration of Professor Yoshinori Takahashi’s retirement from University of Hyogo, Japan. Here, I also explain some of his works contributing to the development of itinerant magnetism.

  4. Electron Gas Dynamic Conductivity Tensor on the Nanotube Surface in Magnetic Field

    Directory of Open Access Journals (Sweden)

    A. M. Ermolaev

    2011-01-01

    Full Text Available Kubo formula was derived for the electron gas conductivity tensor on the nanotube surface in longitudinal magnetic field considering spatial and time dispersion. Components of the degenerate and nondegenerate electron gas conductivity tensor were calculated. The study has showed that under high electron density, the conductivity undergoes oscillations of de Haas-van Alphen and Aharonov-Bohm types with the density of electrons and magnetic field changes.

  5. High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

    Energy Technology Data Exchange (ETDEWEB)

    Bizen, Teruhiko [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)]. E-mail: bizen@spring8.or.jp; Asano, Yoshihiro [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Marechal, Xavier-Marie [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Seike, Takamitsu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Aoki, Tsuyoshi [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Fukami, Kenji [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hosoda, Naoyasu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yonehara, Hiroto [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takagi, Tetsuya [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hara, Toru [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Tanaka, Takashi [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kitamura, Hideo [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

    2007-05-11

    High-energy electron-beam bombardment of Nd{sub 2}Fe{sub 14}B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small.

  6. High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

    International Nuclear Information System (INIS)

    Bizen, Teruhiko; Asano, Yoshihiro; Marechal, Xavier-Marie; Seike, Takamitsu; Aoki, Tsuyoshi; Fukami, Kenji; Hosoda, Naoyasu; Yonehara, Hiroto; Takagi, Tetsuya; Hara, Toru; Tanaka, Takashi; Kitamura, Hideo

    2007-01-01

    High-energy electron-beam bombardment of Nd 2 Fe 14 B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small

  7. Single spectrometer station for neutrino-tagging

    International Nuclear Information System (INIS)

    Nedyalkov, I.P.

    1984-01-01

    A neutrino tagging station built with respect to the following scheme is proposed. A beam of muons and kaons passes through a magnetic spectrometer, where the energy of each particle is measured. There are coordinate detectors behind the spectrometer in several planes, where the direction of the trajectory of a given particle is determined. Thus, mesons enter the decay point wth the known 4-momentum. Behind the decay point the direction of μ-meson generated by the decay of parent mesons is measured. It is shown that information is sufficient for determining the kind of parent particle (pion or kaon), the energy and the direction of trajectory of the neutrino

  8. Electronic transport and magnetization dynamics in magnetic systems

    International Nuclear Information System (INIS)

    Borlenghi, Simone

    2011-01-01

    The aim of this thesis is to understand the mutual influence between electronic transport and magnetization dynamics in magnetic hybrid metallic nano-structures. At first, we have developed a theoretical model, based on random matrix theory, to describe at microscopic level spin dependent transport in a heterogeneous nano-structure. This model, called Continuous Random Matrix Theory (CRMT), has been implemented in a simulation code that allows one to compute local (spin torque, spin accumulation and spin current) and macroscopic (resistance) transport properties of spin valves. To validate this model, we have compared it with a quantum theory of transport based on the non equilibrium Green's functions formalism. Coupling the two models has allowed to perform a multi-scale description of metallic hybrid nano-structures, where ohmic parts are described using CRMT, while purely quantum parts are described using Green's functions. Then, we have coupled CRMT to a micro-magnetic simulation code, in order to describe the complex dynamics of the magnetization induced by spin transfer effect. The originality of this approach consists in modelling a spectroscopic experiment based on a mechanical detection of the ferromagnetic resonance, and performed on a spin torque nano-oscillator. This work has allowed us to obtain the dynamical phase diagram of the magnetization, and to detect the selection rules for spin waves induced by spin torque, as well as the competition between the Eigen-modes of the system when a dc current flows through the multilayer, in partial agreement with experimental data. (author)

  9. Electron Emission by N6+ Ions Scattered at a Magnetized Iron Surface

    International Nuclear Information System (INIS)

    Solleder, B.; Lemell, C.; Burgdoerfer, J.; Tokesi, K.

    2006-01-01

    Complete text of publication follows. Magnetized materials are of considerable interest in the electronics industry (hard discs, spintronics, etc.). A detailed understanding of the properties of magnetized surfaces is therefore important to optimize technical applications. In the last decades, different experimental techniques have been developed to probe spin effects in magnetized materials. In this work the spin polarization of electrons emitted during the impact of N 6+ ions on a magnetized Fe surface is investigated. We study potential emission (PE) of electrons as well as secondary electron (SE) production and transport in the target with the help of Monte Carlo (MC) simulations. Spin dependence of electron transfer processes and of transport in the solid are included. Fig. 1 shows the results of our simulation for the energy distribution and spin polarization of emitted electrons in comparison with experimental data of Pfandzelter et al. [1] for the interaction of N 6+ ions with magnetized Fe. Electrons with energies higher than 200 eV are predominantly PE electrons, emitted close to the surface via autoionization (AI), Auger capture (AC) and Auger deexcitation (AD) channels. Low energy electrons are dominated by promoted, autoionized, and secondary electrons. The polarization of above surface electrons is determined by the high of the potential barrier separating projectile and target. At large distances, the barrier drops only slightly below the Fermi edge and enables transitions of electrons from this part of the band structure which has about 50% polarization. These electrons are transferred to high n states feeding promotion and AI processes between high lying states. Electrons emitted by these processes therefore reflect the polarization near the Fermi edge. Close to the surface, the barrier is low enough to allow for electron capture from the entire conduction band. K-Auger electrons are emitted in immediate vicinity of the surface and therefore mirror

  10. Magnetism in grain-boundary phase of a NdFeB sintered magnet studied by spin-polarized scanning electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kohashi, Teruo, E-mail: teruo.kohashi.fc@hitachi.com; Motai, Kumi [Central Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-0395 (Japan); Nishiuchi, Takeshi; Hirosawa, Satoshi [Magnetic Materials Research Laboratory, Hitachi Metals Ltd., Osaka 618-0013 (Japan)

    2014-06-09

    The magnetism in the grain-boundary phase of a NdFeB sintered magnet was measured by spin-polarized scanning electron microscopy (spin SEM). A sample magnet was fractured in the ultra-high-vacuum chamber to avoid oxidation, and its magnetizations in the exposed grain-boundary phase on the fracture surface were evaluated through the spin polarization of secondary electrons. Spin-SEM images were taken as the fracture surface was milled gradually by argon ions, and the magnetization in the grain-boundary phase was quantitatively obtained separately from that of the Nd{sub 2}Fe{sub 14}B phase. The obtained magnetization shows that the grain-boundary phase of this magnet has substantial magnetization, which was confirmed to be ferromagnetic.

  11. The magnetic recoil spectrometer (MRSt) for time-resolved measurements of the neutron spectrum at the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Frenje, J. A., E-mail: jfrenje@psfc.mit.edu; Wink, C. W.; Gatu Johnson, M.; Li, C. K.; Séguin, F. H.; Petrasso, R. D. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Hilsabeck, T. J.; Kilkenny, J. D. [General Atomics, San Diego, California 92186 (United States); Bell, P.; Bionta, R.; Cerjan, C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2016-11-15

    The next-generation magnetic recoil spectrometer for time-resolved measurements of the neutron spectrum has been conceptually designed for the National Ignition Facility. This spectrometer, called MRSt, represents a paradigm shift in our thinking about neutron spectrometry for inertial confinement fusion applications, as it will provide simultaneously information about the burn history and time evolution of areal density (ρR), apparent ion temperature (T{sub i}), yield (Y{sub n}), and macroscopic flows during burn. From this type of data, an assessment of the evolution of the fuel assembly, hotspot, and alpha heating can be made. According to simulations, the MRSt will provide accurate data with a time resolution of ∼20 ps and energy resolution of ∼100 keV for total neutron yields above ∼10{sup 16}. At lower yields, the diagnostic will be operated at a higher-efficiency, lower-energy-resolution mode to provide a time resolution of ∼20 ps.

  12. The magnetic recoil spectrometer (MRSt) for time-resolved measurements of the neutron spectrum at the National Ignition Facility (NIF).

    Science.gov (United States)

    Frenje, J A; Hilsabeck, T J; Wink, C W; Bell, P; Bionta, R; Cerjan, C; Gatu Johnson, M; Kilkenny, J D; Li, C K; Séguin, F H; Petrasso, R D

    2016-11-01

    The next-generation magnetic recoil spectrometer for time-resolved measurements of the neutron spectrum has been conceptually designed for the National Ignition Facility. This spectrometer, called MRSt, represents a paradigm shift in our thinking about neutron spectrometry for inertial confinement fusion applications, as it will provide simultaneously information about the burn history and time evolution of areal density (ρR), apparent ion temperature (T i ), yield (Y n ), and macroscopic flows during burn. From this type of data, an assessment of the evolution of the fuel assembly, hotspot, and alpha heating can be made. According to simulations, the MRSt will provide accurate data with a time resolution of ∼20 ps and energy resolution of ∼100 keV for total neutron yields above ∼10 16 . At lower yields, the diagnostic will be operated at a higher-efficiency, lower-energy-resolution mode to provide a time resolution of ∼20 ps.

  13. Multiplate ionization total absorption spectrometer with a compressed gas

    International Nuclear Information System (INIS)

    Baskakov, V.I.; Dolgoshein, B.A.; Kantserov, V.A.

    1978-01-01

    The characteristics of a multiplate total absorption spectrometer working with the compressed xenon (up to 25 atm) containing up to 23 radiation lengths of matter are studied. The dependence of the spectrometer energy resolution on the detecting matter density, on the material and thickness of the absorber plates has been studied. The ability of the spectrometer with a tungsten absorber to select hadrons and electrons with P=6 GeV/c by total energy release and characteristics of the cascade longitudinal development has been also studied. The gas spectrometer as it is shown differs quite slightly from the similar spectrometer with liquid argon as for its time resolution it is much better

  14. The Fourier Imaging X-ray Spectrometer (FIXS) for the Argentinian, Scout-launched satelite de Aplicaciones Cienficas-1 (SAC-1)

    Science.gov (United States)

    Dennis, Brian R.; Crannell, Carol JO; Desai, Upendra D.; Orwig, Larry E.; Kiplinger, Alan L.; Schwartz, Richard A.; Hurford, Gordon J.; Emslie, A. Gordon; Machado, Marcos; Wood, Kent

    1988-01-01

    The Fourier Imaging X-ray Spectrometer (FIXS) is one of four instruments on SAC-1, the Argentinian satellite being proposed for launch by NASA on a Scout rocket in 1992/3. The FIXS is designed to provide solar flare images at X-ray energies between 5 and 35 keV. Observations will be made on arcsecond size scales and subsecond time scales of the processes that modify the electron spectrum and the thermal distribution in flaring magnetic structures.

  15. A superheterodyne spectrometer for electronic paramagnetic. Resonance; Spectrometre superheterodyne de resonance paramagnetique electronique

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-12-15

    After a few generalities about electron paramagnetic resonance, a consideration of different experimental techniques authorises the choice of a particular type of apparatus. An EPR superheterodyne spectrometer built in the laboratory and having a novel circuit is described in detail. With this apparatus, many experimental results have been obtained and some of these are described as example. (author) [French] Apres quelques generalites sur le phenomene de resonance paramagnetique electronique, une synthese des differentes techniques experimentales, permet de fixer le choix d'un type d'appareillage. Un spectrometre de RPE superheterodyne realise en laboratoire et comportant un circuit original est expose dans le detail. Cet appareil a permis de nombreux resultats experimentaux dont quelques-uns sont decrits a titre d'exemple. (auteur)

  16. Development of cold neutron spectrometers

    International Nuclear Information System (INIS)

    Lee, Changhee; Lee, C. H.; So, J. Y.; Park, S.; Han, Y. S.; Cho, S. J.; Moon, M. K.; Choi, Y. H.; Sun, G. M.

    2012-03-01

    □ Cold Neutron Triple Axsis Spectrometer (Cold-TAS) Development Ο Fabrication and Installation of the Major Cold-TAS Components Ο Performance Test of the Cold-TAS □ Cold Neutron Time-of-Flight Spectrometer(DC-TOF) Development Ο Fabrication of the Major DC-TOF Components Ο Development DC-TOF Data Reduction Software □ Expected Contribution The two world-class inelastic neutron scattering instruments measure atomic or molecular scale dynamics of meV energy range. This unprecedented measurement capability in the country will enable domestic and international scientists to observe new phenomena in their materials research to obtain world class results. Especially those who work in the fields of magnetic properties of superconductors and multiferroics, molecular dynamics, etc. will get more benefit from these two instruments

  17. Energetic Electron Acceleration and Injection During Dipolarization Events in Mercury's Magnetotail

    Science.gov (United States)

    Dewey, Ryan M.; Slavin, James A.; Raines, Jim M.; Baker, Daniel N.; Lawrence, David J.

    2017-12-01

    Energetic particle bursts associated with dipolarization events within Mercury's magnetosphere were first observed by Mariner 10. The events appear analogous to particle injections accompanying dipolarization events at Earth. The Energetic Particle Spectrometer (3 s resolution) aboard MESSENGER determined the particle bursts are composed entirely of electrons with energies ≳ 300 keV. Here we use the Gamma-Ray Spectrometer high-time-resolution (10 ms) energetic electron measurements to examine the relationship between energetic electron injections and magnetic field dipolarization in Mercury's magnetotail. Between March 2013 and April 2015, we identify 2,976 electron burst events within Mercury's magnetotail, 538 of which are closely associated with dipolarization events. These dipolarizations are detected on the basis of their rapid ( 2 s) increase in the northward component of the tail magnetic field (ΔBz 30 nT), which typically persists for 10 s. Similar to those at Earth, we find that these dipolarizations appear to be low-entropy, depleted flux tubes convecting planetward following the collapse of the inner magnetotail. We find that electrons experience brief, yet intense, betatron and Fermi acceleration during these dipolarizations, reaching energies 130 keV and contributing to nightside precipitation. Thermal protons experience only modest betatron acceleration. While only 25% of energetic electron events in Mercury's magnetotail are directly associated with dipolarization, the remaining events are consistent with the Near-Mercury Neutral Line model of magnetotail injection and eastward drift about Mercury, finding that electrons may participate in Shabansky-like closed drifts about the planet. Magnetotail dipolarization may be the dominant source of energetic electron acceleration in Mercury's magnetosphere.

  18. Electron thermal confinement in a partially stochastic magnetic structure

    Science.gov (United States)

    Morton, L. A.; Young, W. C.; Hegna, C. C.; Parke, E.; Reusch, J. A.; Den Hartog, D. J.

    2018-04-01

    Using a high-repetition-rate Thomson scattering diagnostic, we observe a peak in electron temperature Te coinciding with the location of a large magnetic island in the Madison Symmetric Torus. Magnetohydrodynamic modeling of this quasi-single helicity plasma indicates that smaller adjacent islands overlap with and destroy the large island flux surfaces. The estimated stochastic electron thermal conductivity ( ≈30 m 2/s ) is consistent with the conductivity inferred from the observed Te gradient and ohmic heating power. Island-shaped Te peaks can result from partially stochastic magnetic islands.

  19. "Diffusion" region of magnetic reconnection: electron orbits and the phase space mixing

    Science.gov (United States)

    Kropotkin, Alexey P.

    2018-05-01

    The nonlinear dynamics of electrons in the vicinity of magnetic field neutral lines during magnetic reconnection, deep inside the diffusion region where the electron motion is nonadiabatic, has been numerically analyzed. Test particle orbits are examined in that vicinity, for a prescribed planar two-dimensional magnetic field configuration and with a prescribed uniform electric field in the neutral line direction. On electron orbits, a strong particle acceleration occurs due to the reconnection electric field. Local instability of orbits in the neighborhood of the neutral line is pointed out. It combines with finiteness of orbits due to particle trapping by the magnetic field, and this should lead to the effect of mixing in the phase space, and the appearance of dynamical chaos. The latter may presumably be viewed as a mechanism producing finite conductivity in collisionless plasma near the neutral line. That conductivity is necessary to provide violation of the magnetic field frozen-in condition, i.e., for magnetic reconnection to occur in that region.

  20. Quantitative in situ magnetization reversal studies in Lorentz microscopy and electron holography

    International Nuclear Information System (INIS)

    Rodríguez, L.A.; Magén, C.; Snoeck, E.; Gatel, C.; Marín, L.; Serrano-Ramón, L.

    2013-01-01

    A generalized procedure for the in situ application of magnetic fields by means of the excitation of the objective lens for magnetic imaging experiments in Lorentz microscopy and electron holography is quantitatively described. A protocol for applying magnetic fields with arbitrary in-plane magnitude and orientation is presented, and a freeware script for Digital Micrograph ™ is provided to assist the operation of the microscope. Moreover, a method to accurately reconstruct hysteresis loops is detailed. We show that the out-of-plane component of the magnetic field cannot be always neglected when performing quantitative measurements of the local magnetization. Several examples are shown to demonstrate the accuracy and functionality of the methods. - Highlights: • Generalized procedure for application of magnetic fields with the TEM objective lens. • Arbitrary in-plane magnetic field magnitude and orientation can be applied. • Method to accurately reconstruct hysteresis loops by electron holography. • Out-of-plane field component should be considered in quantitative measurements. • Examples to illustrate the method in Lorentz microscopy and electron holography

  1. Installation And Test Of Electron Beam Generation System To Produce Far-Infrared Radiation And X-Ray Pulses

    International Nuclear Information System (INIS)

    Wichaisirimongkol, Pathom; Jinamoon, Witoon; Khangrang, Nopadon; Kusoljariyakul, Keerati; Rhodes, Michael W.; Rimjaem, Sakhorn; Saisut, Jatuporn; Chitrlada, Thongbai; Vilaithong, Thiraphat; Wiedemann, Helmut

    2005-10-01

    SURIYA project at the Fast Neutron Research Facility, Chiang Mai University, aims to establish a facility to generate femtosecond electron beams. This electron beam can be used to generate high intensity far-infrared radiation and ultra-short X-ray pulses. The main components of the system are a 3 MeV RF electron gun with a thermionic cathode, an a-magnet as a bunch compressor, and post acceleration 15-20 MeV by a linear accelerator (linac). Between the main components, there are focusing quadrupole magnets and steering magnets to maintain the electron beam within a high vacuum tube. At the end of the beam transport line, a dipole magnet has been installed to function as a beam dump and an energy spectrometer. After the installation and testing of individual major components were completed, we have been investigating the generation of the electron beam, intense far- infrared radiation and ultra short X-ray pulses

  2. Electron beam fabrication and characterization of high- resolution magnetic force microscopy tips

    NARCIS (Netherlands)

    Ruhrig, M.; Rührig, M.; Porthun, S.; Porthun, S.; Lodder, J.C.; Mc vitie, S.; Heyderman, L.J.; Johnston, A.B.; Chapman, J.N.

    1996-01-01

    The stray field, magnetic microstructure, and switching behavior of high‐resolution electron beam fabricated thin film tips for magnetic force microscopy (MFM) are investigated with different imaging modes in a transmission electron microscope (TEM). As the tiny smooth carbon needles covered with a

  3. Hybridization of electron states in a step quantum well in a magnetic field

    International Nuclear Information System (INIS)

    Barseghyan, M.G.; Kirakosyan, A.A.

    2005-01-01

    The quantum states and energy levels of an electrion in a rectangular step quantum well in a magnetic field parallel to the plane of two-dimentional electron gas are investigated. It is shown that the joint effect of the magnetic field and confining potential of the quantum well results in redical change of the electron spectrum. The dependence of the electron energy levels on the quantum well parameters, magnetic field induction and projection of the wave-vector along the magnetic field induction are calculated. Numerical calculations are carried out for a AlAs/GaAlAs/GaAs/AlAs step quantum well

  4. Possibility of testing the light dark matter hypothesis with the alpha magnetic spectrometer.

    Science.gov (United States)

    Hooper, Dan; Xue, Wei

    2013-01-25

    The spectrum and morphology of gamma rays from the Galactic center and the spectrum of synchrotron emission observed from the Milky Way's radio filaments have each been interpreted as possible signals of ∼ 7-10 GeV dark matter particles annihilating in the inner Galaxy. In dark matter models capable of producing these signals, the annihilations should also generate significant fluxes of ∼ 7-10 GeV positrons which can lead to a distinctive bumplike feature in a local cosmic ray positron spectrum. In this Letter, we show that while such a feature would be difficult to detect with PAMELA, it would likely be identifiable by the currently operating Alpha Magnetic Spectrometer experiment. As no known astrophysical (i.e., nondark matter) sources or mechanisms are likely to produce such a sharp feature, the observation of a positron bump at around 7-10 GeV would significantly strengthen the case for a dark matter interpretation of the reported gamma-ray and radio anomalies.

  5. Neutron spin echo spectrometer at JRR-3M

    International Nuclear Information System (INIS)

    Takeda, Takayoshi; Komura, Shigehiro; Seto, Hideki; Nagai, Michihiro; Kobayashi, Hideki; Yokoi, Eiji; Ebisawa, Tooru; Tasaki, Seiji.

    1993-01-01

    We have designed and have been constructing at C 2-2 cold neutron guide port of JRR-3M, JAERI, a neutron spin echo spectrometer (NSE) which is equipped with two optimized magnets for neutron spin precession, a position sensitive detector (PSD), a converging polarizer and a wide area analyzer. The dynamic range of scattering vector Q covers from 0.01 A -1 to 0.3 A -1 and that of energy E from 30neV to 0.1meV. This spectrometer makes it possible to study a mesoscopic spatial structure of the order of 1-100nm combined with a nanosecond temporal structure of the order of 0.1-100ns corresponding to dynamical behavior of large molecules such as polymer. A test experiment shows that the homogeneity condition of the precession magnet is loosened by means of PSD. (author)

  6. A Shuttle Upper Atmosphere Mass Spectrometer /SUMS/ experiment

    Science.gov (United States)

    Blanchard, R. C.; Duckett, R. J.; Hinson, E. W.

    1982-01-01

    A magnetic mass spectrometer is currently being adapted to the Space Shuttle Orbiter to provide repeated high altitude atmosphere data to support in situ rarefied flow aerodynamics research, i.e., in the high velocity, low density flight regime. The experiment, called Shuttle Upper Atmosphere Mass Spectrometer (SUMS), is the first attempt to design mass spectrometer equipment for flight vehicle aerodynamic data extraction. The SUMS experiment will provide total freestream atmospheric quantitites, principally total mass density, above altitudes at which conventional pressure measurements are valid. Experiment concepts, the expected flight profile, tradeoffs in the design of the total system and flight data reduction plans are discussed. Development plans are based upon a SUMS first flight after the Orbiter initial development flights.

  7. NONTHERMALLY DOMINATED ELECTRON ACCELERATION DURING MAGNETIC RECONNECTION IN A LOW-β PLASMA

    International Nuclear Information System (INIS)

    Li, Xiaocan; Li, Gang; Guo, Fan; Li, Hui

    2015-01-01

    By means of fully kinetic simulations, we investigate electron acceleration during magnetic reconnection in a nonrelativistic proton–electron plasma with conditions similar to solar corona and flares. We demonstrate that reconnection leads to a nonthermally dominated electron acceleration with a power-law energy distribution in the nonrelativistic low-β regime but not in the high-β regime, where β is the ratio of the plasma thermal pressure and the magnetic pressure. The accelerated electrons contain most of the dissipated magnetic energy in the low-β regime. A guiding-center current description is used to reveal the role of electron drift motions during the bulk nonthermal energization. We find that the main acceleration mechanism is a Fermi-type acceleration accomplished by the particle curvature drift motion along the electric field induced by the reconnection outflows. Although the acceleration mechanism is similar for different plasma β, low-β reconnection drives fast acceleration on Alfvénic timescales and develops power laws out of thermal distribution. The nonthermally dominated acceleration resulting from magnetic reconnection in low-β plasma may have strong implications for the  highly efficient electron acceleration in solar flares and other astrophysical systems

  8. Wave functions for a relativistic electron in superstrong magnetic fields

    International Nuclear Information System (INIS)

    Dumitrescu, Gh.

    2003-01-01

    In the past decade few authors attempted to search interesting features of the radiation of a specific neutron star, the magnetar. In this paper we investigate some features of the motion of an electron in a strong magnetic field as it occurs in a magnetar atmosphere. We have applied the conditions of the super relativistic electrons in super-strong magnetic fields proposed by Gonthier et al. to express two specific spin operators and their eigenfunctions. We have done this in order to investigate into a further paper an estimation of the cross section in Compton process in strong and superstrong magnetic fields in relativistic regime. (author)

  9. Magnetic resonance in zero-field: construction of a spectrometer, evaluation of a method for structure studies

    International Nuclear Information System (INIS)

    Llor, M.

    1987-01-01

    The method known as Nuclear Resonance in the zero-field, applied to the spectral analysis of powders, is discussed. In the method, the anisotropy due to the preferential direction of the magnetic field is suppressed, but a high sensitivity is keeped. For powders spectra, the process allows the obtention resolutions, of dipolar and quadrupolar couplings, in the range of those only obtained on monocrystals under strong fields. By suitable magnetic field oscillations, and by the effect of the high field on the RMN signal, the transient evolutions of the spins are obtained. Concerning the absence of a preferred direction in the zero-field, a powder or the monocrystals show nearly the same behavior. In such conditions, a much more interesting spectra than those from a powder in a strong field, can be obtained. The RMN spectrometer is described. The possibilities, the experimental and theoretical limits of the proposed method, are analyzed. Applications on dipolar (proton and phosphor) and quadrupolar (deuterium) interactions, on hydrated salts and on cyclophasphazenes are carried out [fr

  10. Electronic structure and magnetic anisotropy of Sm2Fe17Nx

    Science.gov (United States)

    Akai, Hisazumi; Ogura, Masako

    2014-03-01

    Electronic structure and magnetic properties of Sm2Fe17Nx are studies on the basis of the first-principles electronic structure calculation in the framework of the density functional theory within the local density and coherent potential approximations. The magnetic anisotropy of the system as a function of nitrogen concentration x is discussed by taking account not only of the crystal field effects but also of the effects of the f-electron transfer from Sm to the neighboring sites. Also discussed is the magnetic transition temperature that is estimated by mapping the system into a Heisenberg model. The results show the crystalline magnetic anisotropy changes its direction from in-plane to uniaxial ones as x increases. It takes the maximum value near x ~ 2 . 8 and then decreases slightly towards x = 3 . The mechanism for these behaviors is discussed in the light of the results of detailed calculations on the bonding properties between Sm and its neighboring N. This work was partly supported by Elements Strategy Initiative Center for Magnetic Materials Project, the Ministry of Education, Culture, Sports, Science and Technology, Japan.

  11. Electron-Bernstein Waves in Inhomogeneous Magnetic Fields

    DEFF Research Database (Denmark)

    Armstrong, R. J.; Frederiksen, Å.; Pécseli, Hans

    1984-01-01

    The propagation of small amplitude electron-Bernstein waves in different inhomogeneous magnetic field geometries is investigated experimentally. Wave propagation towards both cut-offs and resonances are considered. The experimental results are supported by a numerical ray-tracing analysis. Spatia...

  12. Simulation of therapeutic electron beam tracking through a non-uniform magnetic field using finite element method.

    Science.gov (United States)

    Tahmasebibirgani, Mohammad Javad; Maskani, Reza; Behrooz, Mohammad Ali; Zabihzadeh, Mansour; Shahbazian, Hojatollah; Fatahiasl, Jafar; Chegeni, Nahid

    2017-04-01

    In radiotherapy, megaelectron volt (MeV) electrons are employed for treatment of superficial cancers. Magnetic fields can be used for deflection and deformation of the electron flow. A magnetic field is composed of non-uniform permanent magnets. The primary electrons are not mono-energetic and completely parallel. Calculation of electron beam deflection requires using complex mathematical methods. In this study, a device was made to apply a magnetic field to an electron beam and the path of electrons was simulated in the magnetic field using finite element method. A mini-applicator equipped with two neodymium permanent magnets was designed that enables tuning the distance between magnets. This device was placed in a standard applicator of Varian 2100 CD linear accelerator. The mini-applicator was simulated in CST Studio finite element software. Deflection angle and displacement of the electron beam was calculated after passing through the magnetic field. By determining a 2 to 5cm distance between two poles, various intensities of transverse magnetic field was created. The accelerator head was turned so that the deflected electrons became vertical to the water surface. To measure the displacement of the electron beam, EBT2 GafChromic films were employed. After being exposed, the films were scanned using HP G3010 reflection scanner and their optical density was extracted using programming in MATLAB environment. Displacement of the electron beam was compared with results of simulation after applying the magnetic field. Simulation results of the magnetic field showed good agreement with measured values. Maximum deflection angle for a 12 MeV beam was 32.9° and minimum deflection for 15 MeV was 12.1°. Measurement with the film showed precision of simulation in predicting the amount of displacement in the electron beam. A magnetic mini-applicator was made and simulated using finite element method. Deflection angle and displacement of electron beam were calculated. With

  13. Relation between parameters of self-sustaining magnetically confined electron cloud and external conditions

    International Nuclear Information System (INIS)

    Yu Qingchang

    1991-01-01

    On the basis of the fluid theory of the axisymmetrical self-sustaining magnetically confined electron clouds an approximate analytical method is developed. By means of this method the relations between the parameters of this type of electron cloud and external conditions are studied. The parameters include electron density, electron temperature, drift angular frequency of electrons, radius of the electron cloud and electric potential at the centre of the electron cloud. They depend on the voltage, magnetic induction, pressure, electromagnetic field distribution in the confinement device and parameters of electron-atom collisions

  14. IN5 Polarisation Option (IPOP) and HIgh FIeld Magnet Option (HIFIMO) for the IN5 time-of-flight spectrometer

    International Nuclear Information System (INIS)

    Ollivier, J.; Mutka, H.

    2011-01-01

    The new secondary spectrometer for the cold neutron time-of-flight (ToF) instrument IN5 was built with non-magnetic material, keeping in mind the upgrade option of polarisation analysis (PA) and the possibility of applying high continuous magnetic fields. The refurbished instrument has a high incident flux and elevated count-rate and offers a unique opportunity for applying polarised neutron methods for high resolution inelastic scattering, including single crystal investigations. On IN5 the polarised option would use the PASTIS concept of three sets of compact perpendicular coils (see the PANTHER proposal) allowing XYZPA and a 3 He analyser banana. As for high magnetic fields: a magnet suitable for ToF instruments must place a minimal amount of material in the incoming and outgoing beams and provide a large asymmetric view towards the detectors. An homogeneous field area of about 20 mm diameter over 30 mm height is also required. There is a size constraint set by the 800 mm diameter sample chamber and the optimal angular acceptance towards the detectors is -12 degrees / +135 degrees in the equatorial plane and +/- 22 degrees in the vertical direction

  15. Anomalous transport of magnetized electrons interacting with EC waves

    Energy Technology Data Exchange (ETDEWEB)

    Tsironis, C; Vlahos, L [Section of Astrophysics, Astronomy and Mechanics, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2005-01-01

    We consider the nonlinear interaction of magnetized electrons with an oblique narrow-band electromagnetic wave-packet. The interaction is analysed over and near the local threshold to chaos. The statistical character of the forcing that controls the trajectories of the particles is also studied. We focus our analysis on issues related to energy and spatial diffusion across the magnetic field by following the evolution of the ensemble mean squares (({gamma} - {gamma}{sub 0}){sup 2}) and ((r{sub perpendicular}-r{sub perpendicular0}){sup 2}) for various values of the wave amplitude and angle of wave propagation. We study, in particular, the interaction of magnetized electrons with waves having strong and moderate amplitudes, near the transition to chaos, where the dynamics is complex and a mixture of periodic and stochastic orbits coexist. The electron diffusions in real and energy spaces are found to obey simple power laws in time, and the scaling exponents are indicative of sub-diffusion. This is a direct consequence of the effect of the resonant phase-space islands in the particle motion.

  16. Quantitative study of magnetic field distribution by electron holography and micromagnetic simulations

    International Nuclear Information System (INIS)

    Beleggia, M.; Schofield, M.A.; Zhu, Y.; Malac, M.; Liu, Z.; Freeman, M.

    2003-01-01

    The magnetic configuration of a submicrometer Ni 88 Fe 12 permalloy island has been quantitatively mapped by off-axis electron holography. The two main contributions to the electron-optical phase shift, namely the phase shifts induced by the electrostatic and magnetic potentials, including fringing fields, were separated by inverting the specimen of 180 deg. with respect to the electron beam and directly measuring the mean inner potential. A quantitative map of the projected magnetic induction in the sample was thereby retrieved and compared to results of micromagnetic and electromagnetic calculations, providing the minimum-energy configuration and the phase shift, respectively

  17. Electron tomography of porous materials and magnetic nanoparticles

    International Nuclear Information System (INIS)

    Uusimäki, T.

    2015-01-01

    Electron tomography, as carried out in a transmission electron microscope is a method to reveal the three dimensional structure of the sample at the nanometer scale. It is based on tilting the sample and recording subsequent images at different projections angles. Using specific reconstruction algorithms the density distribution of the sample can then be reproduced. In this thesis, electron tomography has been implemented for material science specimens and more rigorously to porous media infiltrated with magnetic nanoparticles. The volume and spatial distribution along with the knowledge of the demagnetizing factors were then used within a magnetic Monte Carlo simulation to predict the magnetic response of the nanoparticle assembly. The local curvature of nanoparticles within the template, known to be a critical geometrical parameter influencing material properties, was extracted with two distinctive methods. Furthermore, new capabilities needed for image analysis and processing of the tilt series had to be implemented for improved alignments and segmentation. A new method to align the tilt series without depending on markers was written for obtaining high quality reconstructions. Also a comparison was made between different scanning TEM acquisition modes such as incoherent bright field and high angle annular dark field imaging modes with respect to resolution and contrast changes. (author) [de

  18. Development and testing of a double-focusing, static, axisymmetric mass spectrometer

    International Nuclear Information System (INIS)

    Ritter, G.

    1979-04-01

    The developed mass spectrometer affords very high acceptance (cm 2 sr) compared with conventional mass spectrometers owing to its large solid angle of 0.178 sr. The ion optical properties of the instrument were tested by bombarding various targets (Al, Ni, Ti, Cu, Si) with potassium or caesium ions from a thermionic ion source with energies of 1, 2 and 3 keV and recording mass spectra of positive and negative sputtered ions. The ion optical beam path was calculated analytically (magnet system) in part and numerically in part (energy analyzer, einzel lenses and detector system) and represented in graph form. The results obtained from the mass spectra showed that the magnet system with its twelve permanent magnets is too irregular to produce mass linses with good resolution. Furthermore, it was found that the maximum primary energy of the alkali ions that was possible in this mass spectrometer owing to the breakdown strength was not sufficient to record surface-specific mass spectra since the target surface was covered within a very short time with an at least monatomic layer of alkali ions from the thermionic ion source. (orig./HP) [de

  19. Electronic and magnetic properties of organic conductors (DMET)2MBr4 (M=Fe, Ga)

    International Nuclear Information System (INIS)

    Enomoto, Kengo; Miyazaki, Akira; Enoki, Toshiaki; Yamaura, Jun-ichi

    2003-01-01

    (DMET) 2 MBr 4 (M=Fe, Ga) are isostructural organic conductors whose crystal structure consists of an alternate stacking of quasi one-dimensional chain-based donor layers and anion square lattices. The resistivity, ESR, magnetic susceptibility, magnetization, and magnetoresistance of these salts were investigated in order to clarify the correlation between the electronic structure and the magnetism. The electronic structures of both salts are metallic down to T MI - 40 K, below which a Mott insulating state is stabilized, accompanied by an SDW transition at T SDW - 25 K. The FeBr 4 salt with Fe 3+ (S=5/2) localized spins undergoes an antiferromagnetic transition at T N = 3.7 K. In the FeBr 4 salt, the magnetization curves, which show field-direction-dependent anomalies in addition to a spin-flop transition, are demonstrated to have a participation of donor π-electron spins in the magnetization processes. The field dependence of the magnetoresistances below T N tracks faithfully that of the magnetization, where the donor π-electrons and Fe 3+ d-electrons are responsible for the former and the latter, respectively. This clearly demonstrates the presence of the π-d interaction that plays an important role in the interplay between electron transport and magnetism. (author)

  20. Conceptual design of the Radial Gamma Ray Spectrometers system for α particle and runaway electron measurements at ITER

    DEFF Research Database (Denmark)

    Nocente, Massimo; Tardocchi, Marco; Barnsley, Robin

    2017-01-01

    We here present the principles and main physics capabilities behind the design of the radial gamma ray spectrometers (RGRS) system for alpha particle and runaway electron measurements at ITER. The diagnostic benefits from recent advances in gamma-ray spectrometry for tokamak plasmas and combines...... the measurements sensitive to α particles at characteristic resonant energies and to possible anisotropies of their slowing down distribution function. An independent assessment of the neutron rate by gamma-ray emission is also feasible. In case of runaway electrons born in disruptions with a typical duration...... of 100ms, a time resolution of at least 10ms for runaway electron studies can be achieved depending on the scenario and down to a current of 40 kA by use of external gas injection. We find that the bremsstrahlung spectrum in the MeV range from confined runaways is sensitive to the electron velocity space...

  1. Extending The Useful Life Of Older Mass Spectrometers

    International Nuclear Information System (INIS)

    Johnson, S.; Cordaro, J.; Holland, M.; Jones, V.

    2010-01-01

    Thermal ionization and gas mass spectrometers are widely used across the Department of Energy (DOE) Complex and contractor laboratories. These instruments support critical missions, where high reliability and low measurement uncertainty are essential. A growing number of these mass spectrometers are significantly older than their original design life. The reality is that manufacturers have declared many of the instrument models obsolete, with direct replacement parts and service no longer available. Some of these obsolete models do not have a next generation, commercially available replacement. Today's budget conscious economy demands for the use of creative funds management. Therefore, the ability to refurbish (or upgrade) these valuable analytical tools and extending their useful life is a cost effective option. The Savannah River Site (SRS) has the proven expertise to breathe new life into older mass spectrometers, at a significant cost savings compared to the purchase and installation of new instruments. A twenty-seven year old Finnigan MAT-261(trademark) Thermal Ionization Mass Spectrometer (TIMS), located at the SRS F/H Area Production Support Laboratory, has been successfully refurbished. Engineers from the Savannah River National Laboratory (SRNL) fabricated and installed the new electronics. These engineers also provide continued instrument maintenance services. With electronic component drawings being DOE Property, other DOE Complex laboratories have the option to extend the life of their aged Mass Spectrometers.

  2. Axis-encircling electron beam generation using a smooth magnetic cusp for gyrodevices

    International Nuclear Information System (INIS)

    He, W.; Whyte, C. G.; Rafferty, E. G.; Cross, A. W.; Phelps, A. D. R.; Ronald, K.; Young, A. R.; Robertson, C. W.; Speirs, D. C.; Rowlands, D. H.

    2008-01-01

    The generation of an annular-shaped axis-encircling electron beam using a smooth magnetic cusp was studied through numerical simulations and experiments for harmonic operation of a gyrodevice. Two magnetic coils were used to form a magnetic cusp located just downstream from the velvet cathode of an accelerator diode. An electron beam of current 34 A and voltage 130 kV with an adjustable velocity ratio α up to 1.2 was fully transported to the downstream uniform magnetic field region and used to drive a gyrotron traveling wave amplifier into saturation

  3. The data acquisition system used in one-dimension multichannel fast electron energy loss spectrometer

    International Nuclear Information System (INIS)

    Jiang Weichun; Zhu Linfan; Zhang Yijun; Xu Kezuo

    2010-01-01

    It describes a data acquisition system used in one dimension multichannel fast electron energy loss spectrometer, which can work in scan acquisition mode and static acquisition mode. The timing precision of the scan mode is less than 4 μs by utilizing the gated signal generated by data acquisition card DAQ2010 and an AND logic circuit. A timer card PCI8554 is used to synchronize the data acquisition card and the personal computer. The scan voltage supply is controlled by the personal computer through the RS232 interface. The multithreading technology is used in the acquisition software in order to improve the accommodating-err ability of the acquisition system. A satisfactory test result is given. (authors)

  4. Photoelectron spectrometer for attosecond spectroscopy of liquids and gases

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, I.; Huppert, M.; Wörner, H. J., E-mail: hwoerner@ethz.ch [Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich (Switzerland); Brown, M. A. [Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich (Switzerland); Bokhoven, J. A. van [Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich (Switzerland); Laboratory for Catalysis and Sustainable Chemistry, Paul Scherrer Institute, 5232 Villigen (Switzerland)

    2015-12-15

    A new apparatus for attosecond time-resolved photoelectron spectroscopy of liquids and gases is described. It combines a liquid microjet source with a magnetic-bottle photoelectron spectrometer and an actively stabilized attosecond beamline. The photoelectron spectrometer permits venting and pumping of the interaction chamber without affecting the low pressure in the flight tube. This pressure separation has been realized through a sliding skimmer plate, which effectively seals the flight tube in its closed position and functions as a differential pumping stage in its open position. A high-harmonic photon spectrometer, attached to the photoelectron spectrometer, exit port is used to acquire photon spectra for calibration purposes. Attosecond pulse trains have been used to record photoelectron spectra of noble gases, water in the gas and liquid states as well as solvated species. RABBIT scans demonstrate the attosecond resolution of this setup.

  5. Photoelectron spectrometer for attosecond spectroscopy of liquids and gases

    International Nuclear Information System (INIS)

    Jordan, I.; Huppert, M.; Wörner, H. J.; Brown, M. A.; Bokhoven, J. A. van

    2015-01-01

    A new apparatus for attosecond time-resolved photoelectron spectroscopy of liquids and gases is described. It combines a liquid microjet source with a magnetic-bottle photoelectron spectrometer and an actively stabilized attosecond beamline. The photoelectron spectrometer permits venting and pumping of the interaction chamber without affecting the low pressure in the flight tube. This pressure separation has been realized through a sliding skimmer plate, which effectively seals the flight tube in its closed position and functions as a differential pumping stage in its open position. A high-harmonic photon spectrometer, attached to the photoelectron spectrometer, exit port is used to acquire photon spectra for calibration purposes. Attosecond pulse trains have been used to record photoelectron spectra of noble gases, water in the gas and liquid states as well as solvated species. RABBIT scans demonstrate the attosecond resolution of this setup

  6. Photoelectron spectrometer for attosecond spectroscopy of liquids and gases

    Science.gov (United States)

    Jordan, I.; Huppert, M.; Brown, M. A.; van Bokhoven, J. A.; Wörner, H. J.

    2015-12-01

    A new apparatus for attosecond time-resolved photoelectron spectroscopy of liquids and gases is described. It combines a liquid microjet source with a magnetic-bottle photoelectron spectrometer and an actively stabilized attosecond beamline. The photoelectron spectrometer permits venting and pumping of the interaction chamber without affecting the low pressure in the flight tube. This pressure separation has been realized through a sliding skimmer plate, which effectively seals the flight tube in its closed position and functions as a differential pumping stage in its open position. A high-harmonic photon spectrometer, attached to the photoelectron spectrometer, exit port is used to acquire photon spectra for calibration purposes. Attosecond pulse trains have been used to record photoelectron spectra of noble gases, water in the gas and liquid states as well as solvated species. RABBIT scans demonstrate the attosecond resolution of this setup.

  7. Technique for comparing AES signals from different spectrometers using common materials

    International Nuclear Information System (INIS)

    Baer, D.R.; Thomas, M.T.

    1985-10-01

    A simple procedure is outlined to obtain relative sensitivity curves that allow data collected on one Auger electron spectrometer to be related to data collected on a different spectrometer or to a standard data set. Data collected on three CMA systems demonstrates that dN/dE peak to peak amplitude ratios for pure elements can vary considerably but in a systematic manner for different systems. Such differences can be produced by variations in system design, by specimen or electron gun alignment, spectrometer contamination or other problems. However if the differences in relative sensitivity are considered in the data analysis, data sets from different systems can be interrelated with reasonable accuracy

  8. Performance of a compact detector package for the out-of-plane spectrometer system

    International Nuclear Information System (INIS)

    Zhou, Z.-L.; Sirca, S.; Boeglin, W.; Sarty, A.J.; Alarcon, R.; Beck, R.; Bernstein, A.; Bertozzi, W.; Botto, T.; Bourgeois, P.; Calarco, J.; Casagrande, F.; Chen, J.; Comfort, J.R.; Dale, D.; Distler, M.O.; Dodson, G.; Dolfini, S.; Dooley, A.; Dow, K.; Epstein, M.; Farkhondeh, M.; Georgakopoulos, S.; Gilad, S.; Hicks, R.; Holtrop, M.; Hotta, A.; Jiang, X.; Joo, K.; Jordan, D.; Kaloskamis, N.; Karabarbounis, A.; Kirkpatrick, J.; Kowalski, S.; Kunz, C.; Liyanage, N.; Mandeville, J.; Margaziotis, D.J.; McIlvain, T.; Mertz, C.; Milner, R.; Miskimen, R.; Nakagawa, I.; Papanicolas, C.N.; Pavan, M.; Peterson, G.; Ramirez, A.; Rowntree, D.; Sato, Y.; Shaw, J.; Six, E.; Sobczynski, S.; Soong, S.-B.; Sparveris, N.; Stave, S.; Stiliaris, S.; Tamae, T.; Tieger, D.; Tschalaer, C.; Tsentalovich, G.; Turchinetz, W.; Vellidis, C.; Warren, G.A.; Weinstein, L.B.; Williamson, S.E.; Young, A.; Zhao, J.; Zwart, T.

    2002-01-01

    We report on the design and performance of compact detector packages currently installed in the four magnetic out-of-plane spectrometers for electron scattering experiments at the MIT-Bates Linear Accelerator Center. The detector packages have been designed to meet the mechanical requirements arising from out-of-plane particle detection. They offer good trajectory and momentum reconstruction, particle identification and time-of-flight measurements for electrons, pions, protons, and deuterons with large momentum bites and in broad kinematical ranges and high luminosities. The detectors have so far been used with great success in out-of-plane measurements of 12 C(e→,e'p), 2 H(e→,e'p), virtual Compton scattering below pion threshold and in studies of the N→Δ transition in both exclusive reaction channels 1 H(e→,e'p)π 0 and 1 H(e→,e'π + )n

  9. A particle identification technique for large acceptance spectrometers

    International Nuclear Information System (INIS)

    Cappuzzello, F.; Cavallaro, M.; Cunsolo, A.; Foti, A.; Carbone, D.; Orrigo, S.E.A.; Rodrigues, M.R.D.

    2010-01-01

    A technique to identify the heavy ions produced in nuclear reactions is presented. It is based on the use of a hybrid detector, which measures the energy loss, the residual energy, the position and angle of the ions at the focal plane of a magnetic spectrometer. The key point is the use of a powerful algorithm for the reconstruction of the ion trajectory, which makes the technique reliable even with large acceptance optical devices. Experimental results with the MAGNEX spectrometer show a remarkable resolution of about 1/160 in the mass parameter.

  10. Electron beam curable branched chain polyurethane acrylates for magnetic media coatings

    International Nuclear Information System (INIS)

    Ukachi, Takashi; Haga, Kei-ichi; Matsumura, Yoshio

    1989-01-01

    Electron beam curable binder resins have been studied to realize the high quality magnetic coatings. It was supposed that resins with a higher crosslink density could lead to magnetic coatings with higher abrasion resistance. Branched chain polyurethane acrylates show a higher degree of cure by irradiation with an electron beam in comparison with linear polyurethane acrylates. This paper describes the potential wear resistance between properties of magnetic coatings and the physical properties of the cured unpigmented branched chain polyurethane acrylates that were used as the binder resins. (author)

  11. Role of electron-electron interactions in the RKKY theory of magnetism

    International Nuclear Information System (INIS)

    Cooke, J.F.

    1978-10-01

    The theory of magnetism in heavy rare earth metals is based on the RKKY theory. In this formalism the indirect exchange interaction between the local 4f spins is mediated by the conduction electrons. When carried to second order in the 4f-conduction electron interaction, traditional perturbation theory leads to a Heisenberg-like interaction between the local spins which depends on the electronic energy bands and 4f-conduction electron exchange matrix elements. This derivation neglects the detailed behavior of electron-electron interaction within the conduction band, which is known to be important in metallic systems. By using an equation of motion method, an expression for the inelastic neutron scattering cross-section has been derived which includes, in an approximate way, this electron-electron interaction. The results of this calculation indicate that spin-wave peaks can be broadened and shifted if the spin-wave band lies near the conduction electron Stoner continuum. The origin of this effect is similar to that found in itinerant electron systems where the spin-wave band actually intersects the Stoner continuum, resulting in the disappearance of the spin-wave mode

  12. Role of electron-electron interactions in the RKKY theory of magnetism

    International Nuclear Information System (INIS)

    Cooke, J.F.

    1979-01-01

    The theory of magnetism in heavy rare earth metals is based on the RKKY theory. In this formalism the indirect exchange interaction between the local 4f spins is mediated by the conduction electrons. When carried to second order in the 4f-conduction electron interaction, traditional pertubation theory leads to a Heisenberg-like interaction between the local spins which depends on the electronic energy bands and 4f-conduction electron exchange matrix elements. This derivation neglects the detailed behavior of electron-electron interaction within the conduction band, which is known to be important in metallic systems. By using an equation of motion method, an expression for the inelastic neutron scattering cross-section has been derived which includes, in an approximate way, this electron-electron interaction. The results of this calculation indicate that spin-wave peaks can be broadened and shifted if the spin-wave band lies near the conduction electron Stoner continuum. The origin of this effect is similar to that found in itinerant electron systems where the spin-wave band actually intersects the Stoner continuum, resulting in the disappearance of the spin-wave mode

  13. NMR spectrometers. Current status and assessment of demand for high-resolution NMR spectrometers and for high-performance, solid NMR spectrometers at the scientific colleges and other research institutes in the Federal Republic of Germany. Pt. 1

    International Nuclear Information System (INIS)

    Schmidt, K.

    1989-01-01

    The survey includes high-resolution NMR spectrometers for liquids and solutions with magnetic field intensities of 11.7 Tesla and more (proton frequencies from 500 to 600 MHz) as well as high-performance solid-state NMR spectrometers with field intensities of, at least, 6.3 Tesla (proton frequencies of 270 MHz and more). The given results which had been obtained from documents of the manufacturers try to meet the manufacturers' need for safety. Market shares and sites are not listed. (DG) [de

  14. Nonlinear Electron Waves in Strongly Magnetized Plasmas

    DEFF Research Database (Denmark)

    Pécseli, Hans; Juul Rasmussen, Jens

    1980-01-01

    Weakly nonlinear dispersive electron waves in strongly magnetized plasma are considered. A modified nonlinear Schrodinger equation is derived taking into account the effect of particles resonating with the group velocity of the waves (nonlinear Landau damping). The possibility of including the ion...... dynamics in the analysis is also demonstrated. As a particular case the authors investigate nonlinear waves in a strongly magnetized plasma filled wave-guide, where the effects of finite geometry are important. The relevance of this problem to laboratory experiments is discussed....

  15. Nanoscale magnetic characterization of tunneling magnetoresistance spin valve head by electron holography.

    Science.gov (United States)

    Park, Hyun Soon; Hirata, Kei; Yanagisawa, Keiichi; Ishida, Yoichi; Matsuda, Tsuyoshi; Shindo, Daisuke; Tonomura, Akira

    2012-12-07

    Nanostructured magnetic materials play an important role in increasing miniaturized devices. For the studies of their magnetic properties and behaviors, nanoscale imaging of magnetic field is indispensible. Here, using electron holography, the magnetization distribution of a TMR spin valve head of commercial design is investigated without and with a magnetic field applied. Characterized is the magnetic flux distribution in complex hetero-nanostructures by averaging the phase images and separating their component magnetic vectors and electric potentials. The magnetic flux densities of the NiFe (shield and 5 nm-free layers) and the CoPt (20 nm-bias layer) are estimated to be 1.0 T and 0.9 T, respectively. The changes in the magnetization distribution of the shield, bias, and free layers are visualized in situ for an applied field of 14 kOe. This study demonstrates the promise of electron holography for characterizing the magnetic properties of hetero-interfaces, nanostructures, and catalysts. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Proposal for a forward spectrometer at the 4π detector

    International Nuclear Information System (INIS)

    Berdermann, E.; Luehning, J.; Lynen, U.; Milkau, U.; Mueller, K.; Sann, H.; Stelzer, H.; Trautmann, W.; Kreutz, P.; Kuehmichel, A.; Pinkenburg, C.; Pochodzalla, J.; Moretto, L.; Mueller, W.F.J.; Wozniak, G.; Imme, G.; Raciti, G.; Adloff, G.C.; Bilwes, B.; Bilwes, R.; Michel, M.; Masse, C.; Rudolf, G.; Scheibling, F.; Stuttge, L.

    1988-03-01

    We propose to complement the 4π detector to be installed at the SIS-ESR facility with a forward spectrometer (ALADiN) capable of detecting and identifying nuclear fragments up to the largest masses and momenta expected at SIS. Positioned behind the time-of-flight wall of the 4π detector the spectrometer should subtend an angular range of approximately ±5 0 in horizontal and at least ±2 0 in vertical direction and thus cover a sufficiently large part of the forward region. In order to satisfy these requirements and to obtain the necessary resolution in mass and momentum the dipole magnet needs, at least, a gap height of 0.5 m, a horizontal acceptance of 1.5 m and a bending power of 2 Tm. The following sections of this proposal start out with a more detailed presentation of the physics motivation which will concentrate on multifragmentation as a new and hitherto unexplored decay mode of nuclear matter under extreme conditions. The description of the spectrometer divides into three sections containing the description of the magnet and the vacuum system, of the detectors needed to track and to identify the fragments, and of the performance of the spectrometer. (orig./HSI)

  17. Photodetachment electron flux of H− in combined electric and magnetic fields with arbitrary orientation

    International Nuclear Information System (INIS)

    Wang, De-hua

    2013-01-01

    Highlights: •On the basis of the semiclassical theory, the photodetachment electron flux of H − in combined electric field and magnetic field with arbitrary orientation has been studied for the first time. •Our calculation results suggest that the electron flux distributions on the detector plane is not only related to the angle between the electric and magnetic fields, but also related to the electron energy. •Our studies may guide the future experimental researches in the photodetachment microscopy of some more complex negative ions in the presence of external fields. -- Abstract: On the basis of the semi-classical theory, we calculate the photodetachment electron flux of H − in combined electric field and magnetic field with arbitrary orientation. Our results suggest that the electron flux distributions on the detector plane is not only related to the angle between the electric and magnetic fields, but also related to the electron energy. With the increase of the angle between the electric and magnetic field, the oscillating region in the electron flux distributions becomes smaller. In addition, we find with the increase of the detached electron's energy, the oscillating structure in the flux distributions becomes much more complicated. Therefore, the oscillation in the detached electron flux distributions can be controlled by adjusting the angle between the electric and magnetic field and the detached electron's energy. We hope that our studies may guide the future experimental researches in the photodetachment microscopy of negative ion in the presence of external fields

  18. The Relationship Between Magnet Designation, Electronic Health Record Adoption, and Medicare Meaningful Use Payments.

    Science.gov (United States)

    Lippincott, Christine; Foronda, Cynthia; Zdanowicz, Martin; McCabe, Brian E; Ambrosia, Todd

    2017-08-01

    The objective of this study was to examine the relationship between nursing excellence and electronic health record adoption. Of 6582 US hospitals, 4939 were eligible for the Medicare Electronic Health Record Incentive Program, and 6419 were eligible for evaluation on the HIMSS Analytics Electronic Medical Record Adoption Model. Of 399 Magnet hospitals, 330 were eligible for the Medicare Electronic Health Record Incentive Program, and 393 were eligible for evaluation in the HIMSS Analytics Electronic Medical Record Adoption Model. Meaningful use attestation was defined as receipt of a Medicare Electronic Health Record Incentive Program payment. The adoption electronic health record was defined as Level 6 and/or 7 on the HIMSS Analytics Electronic Medical Record Adoption Model. Logistic regression showed that Magnet-designated hospitals were more likely attest to Meaningful Use than non-Magnet hospitals (odds ratio = 3.58, P electronic health records than non-Magnet hospitals (Level 6 only: odds ratio = 3.68, P electronic health record use, which involves earning financial incentives for successful adoption. Continued investigation is needed to examine the relationships between the quality of nursing care, electronic health record usage, financial implications, and patient outcomes.

  19. Miniature neutron-alpha activation spectrometer

    International Nuclear Information System (INIS)

    Rhodes, Edgar; Goldsten, John; Holloway, James Paul; He, Zhong

    2002-01-01

    We are developing a miniature neutron-alpha activation spectrometer for in-situ analysis of chem-bio samples, including rocks, fines, ices, and drill cores, suitable for a lander or Rover platform for Mars or outer-planet missions. In the neutron-activation mode, penetrating analysis will be performed of the whole sample using a γ spectrometer and in the α-activation mode, the sample surface will be analyzed using Rutherford-backscatter and x-ray spectrometers. Novel in our approach is the development of a switchable radioactive neutron source and a small high-resolution γ detector. The detectors and electronics will benefit from remote unattended operation capabilities resulting from our NEAR XGRS heritage and recent development of a Ge γ detector for MESSENGER. Much of the technology used in this instrument can be adapted to portable or unattended terrestrial applications for detection of explosives, chemical toxins, nuclear weapons, and contraband

  20. Classical understanding of electron vortex beams in a uniform magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yeong Deok [Department of Computer Science and Engineering, Woosuk University, Wanju, Cheonbuk, 565-701 (Korea, Republic of); Choi, Taeseung, E-mail: tschoi@swu.ac.kr [Division of Applied Food System, College of Natural Science, Seoul Women' s University, Seoul 139-774 (Korea, Republic of); School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea, Republic of)

    2017-04-25

    Recently, interesting observations on electron vortex beams have been made. We propose a classical model that shows vortex-like motion due to suitably-synchronized motion of each electron's cyclotron motion in a uniform magnetic field. It is shown that some basic features of electron vortex beams in a uniform magnetic field, such as azimuthal currents, the relation between energy and kinetic angular momentum, and the parallel-axis theorem are understandable by using this classical model. We also show that the time-dependence of kinetic angular momentum of electron vortex beams could be understood as an effect of a specific nonuniform distribution of classical electrons. - Highlights: • A classical model for electron vortex beams is proposed. • The basic features of azimuthal currents could be understood by using this model. • The kinetic angular momentum of electron vortex beams is intuitively understandable.