Polarized atomic beams for targets

International Nuclear Information System (INIS)

Grueebler, W.

1984-01-01

The basic principle of the production of polarized atomic hydrogen and deuterium beams are reviewed. The status of the present available polarization, density and intensity are presented. The improvement of atomic beam density by cooling the hydrogen atoms to low velocity is discussed. The possible use of polarized atomic beams as targets in storage rings is shown. It is proposed that polarized atomic beams can be used to produce polarized gas targets with high polarization and greatly improved density

A laser-driven source of polarized hydrogen and deuterium

International Nuclear Information System (INIS)

Young, L.; Holt, R.J.; Gilman, R.A.; Kowalczyk, R.; Coulter, K.

1989-01-01

A novel laser-driven polarized source of hydrogen and deuterium which operates on the principle of spin-exchange optical pumping is being developed. This source is designed to operate as an internal target in an electron storage ring for fundamental studies of spin-dependent structure of nuclei. It has the potential to exceed the flux from existing conventional sources (3 times 10 16/ s) by an order of magnitude. Currently, the source delivers hydrogen at a flux of 8 times 10 16 atoms/s with an atomic polarization of 24% and deuterium at 6 times 10 16 atoms/s with a polarization of 29%. Technical obstacles which have been overcome, with varying degrees of success are complete Doppler-coverage in the optical-pumping stage without the use of a buffer gas, wall-induced depolarization and radiation-trapping. Future improvements should allow achievement of the design goals of 4 times 10 17 atoms/s with a polarization of 50%. 8 refs., 2 figs

Development of a hydrogen and deuterium polarized gas target for application in storage rings. Annual report, February 1, 1986-January 31, 1987

International Nuclear Information System (INIS)

Haeberli, W.

1986-01-01

Insertion of an internal polarized gas target into storage rings for protons, antiprotons or electrons would permit interesting new experiments, particularly if the circulating beam is polarized as well. The purpose of the present project is the development of a polarized gas target, based on injection of polarized hydrogen or deuterium atoms into a storage cell in order to build up the required target thickness. A method has been developed and tested, which permits measurement of the target polarization under realistic conditions (i.e., in the presence of an intense ion beam) without the need for a large accelerator. First measurements with an oxidized aluminum cell have been made. It is proposed to study wall depolarization in storage cells and to search for suitable wall conditions (wall material, coating, temperature, vacuum conditions) to permit eventual construction of a polarized gas target for a storage ring

Deuterium high pressure target

International Nuclear Information System (INIS)

Perevozchikov, V.V.; Yukhimchuk, A.A.; Vinogradov, Yu.I.

2001-01-01

The design of the deuterium high-pressure target is presented. The target having volume of 76 cm 3 serves to provide the experimental research of muon catalyzed fusion reactions in ultra-pure deuterium in the temperature range 80-800 K under pressures of up to 150 MPa. The operation of the main systems of the target is described: generation and purification of deuterium gas, refrigeration, heating, evacuation, automated control system and data collection system

Fine target of deuterium

International Nuclear Information System (INIS)

Diaz Diaz, J.; Granados Gonzalez, C. E.; Gutierrez Bernal, R.

1959-01-01

A fine target of deuterium on a tantalum plate by the absorption method is obtained. In order to obtain the de gasification temperature an induction generator of high frequency is used and the deuterium pass is regulated by means of a palladium valve. Two vacuum measures are available, one to measure the high vacuum in the de gasification process of the tantalum plate and the other, for low vacuum, to measure the deuterium inlet in the installation and the deuterium pressure change in the installation after the absorption in the tantalum plate. A target of 48 μ gr/cm 2 thick is obtained. (Author) 1 refs

Spin polarized deuterium

International Nuclear Information System (INIS)

Glyde, H.R.; Hernadi, S.I.

1986-01-01

Several ground state properties of (electron) spin-polarized deuterium (D) such as the energy, single quasiparticle energies and lifetimes, Landau parameters and sound velocities are evaluated. The calculations begin with the Kolos-Wolneiwicz potential and use the Galitskii-FeynmanHartree-Fock (GFHF) approximation. The deuteron nucleas has spin I = 1, and spin states I/sub z/ = 1,0,-1. We explore D 1 , D 2 and D 3 in which, respectively, one spin state only is populated, two states are equally populated, and three states are equally populated. We find the GFHF describes D 1 well, but D 2 and D 3 less well. The Landau parameters, F/sub L/, are small compared to liquid 3 He and very small for doubly polarized D 1 (i.e. the F/sub L/ decrease with nuclear polarization)

Laser driven source of spin polarized atomic deuterium and hydrogen

International Nuclear Information System (INIS)

Poelker, M.; Coulter, K.P.; Holt, R.J.

1993-01-01

Optical pumping of potassium atoms in the presence of a high magnetic field followed by spin exchange collisions with deuterium (hydrogen) is shown to yield a high flux of spin polarized atomic deuterium (hydrogen). The performance of the laser driven source has been characterized as a function of deuterium (hydrogen) flow rate, potassium density, pump laser power, and magnetic field. Under appropriate conditions, the authors have observed deuterium atomic polarization as high as 75% at a flow rate 4.2x10 17 atoms/second. Preliminary results suggest that high nuclear polarizations are obtained in the absence of weak field rf transitions as a result of a spin temperature distribution that evolves through frequent H-H (D-D) collisions

Production of polarized negative deuterium ion beam with dual optical pumping in KEK

Energy Technology Data Exchange (ETDEWEB)

Kinsho, M.; Ikegami, K.; Takagi, A. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan); Mori, Y.

1997-02-01

To obtain highly nuclear-spin vector polarized negative deuterium ion beam, a dual optically pumped polarized negative deuterium ion source has been developed at KEK. It is possible to select a pure nuclear-spin state with this scheme, and negative deuterium ion beam with 100% nuclear-spin vector polarization can be produced in principle. We have obtained about 70% of nuclear-spin vector polarized negative deuterium ion beam so far. This result may open up a new possibilities for the optically pumped polarized ion source. (author)

Polarized internal targets for electronuclear experiments

International Nuclear Information System (INIS)

van den Brand, J.F.J.

1993-01-01

Polarized internal gas targets represent a unique opportunity for the measurement of spin observables in electro-nuclear physics. Two measurements will be discussed. First, spin observables have been measured in elastic and quasi-free scattering of 45, 200, 300, and 415 MeV polarized protons from a polarized 3 He internal gas target at the Indiana University Cyclotron Facility Cooler Ring. The data obtained constitute the first measurement of spin correlation parameters using a storage ring with polarized beam and polarized internal gas target. Second, a quasi-free (e,e'p) experiment using tensor polarized deuterium will be discussed. Here, the goal is the measurement of the S- and D-state parts of the proton spectral function by scattering 700 MeV electrons from an atomic beam source. Large acceptance detectors have been used in both experiments. The internal-target technique has broad applicability in nuclear and particle physics

Laser-driven polarized H/D sources and targets

International Nuclear Information System (INIS)

Clasie, B.; Crawford, C.; Dutta, D.; Gao, H.; Seely, J.; Xu, W.

2005-01-01

Traditionally, Atomic Beam Sources are used to produce targets of nuclear polarized hydrogen (H) or deuterium (D) for experiments using storage rings. Laser-Driven Sources (LDSs) offer a factor of 20-30 gain in the target thickness (however, with lower polarization) and may produce a higher overall figure of merit. The LDS is based on the technique of spin-exchange optical pumping where alkali vapor is polarized by absorbing circularly polarized laser photons. The H or D atoms are nuclear-polarized through spin-exchange collisions with the polarized alkali vapor and through subsequent hyperfine interactions during frequent H-H or D-D collisions

Evidence for Nuclear Tensor Polarization of Deuterium Molecules in Storage Cells

International Nuclear Information System (INIS)

van den Brand, J.; Bulten, H.; Zhou, Z.; Unal, O.; van den Brand, J.; Ferro-Luzzi, M.; Botto, T.; Bouwhuis, M.; Heimberg, P.; de Jager, C.; de Lange, D.; Nooren, G.; Papadakis, N.; Passchier, I.; Poolman, H.; Steijger, J.; Vodinas, N.; de Vries, H.; van den Brand, J.; Ferro-Luzzi, M.; Lang, J.; Alarcon, R.; Dolfini, S.; Ent, R.; Higinbotham, D.

1997-01-01

Deuterium molecules were obtained by recombination, on a copper surface, of deuterium atoms prepared in specific hyperfine states. The molecules were stored for about 5ms in an open-ended cylindrical cell, placed in a 23mT magnetic field, and their tensor polarization was measured by elastic scattering of 704MeV electrons. The results of the measurements are consistent with the deuterium molecules retaining the tensor polarization of the initial atoms. copyright 1997 The American Physical Society

Polarized gas targets for storage rings

International Nuclear Information System (INIS)

Holt, R.J.

1990-01-01

It is widely recognized that polarized gas targets in electron storage rings represent a new opportunity for precision nuclear physics studies. New developments in polarized target technology specific to internal applications will be discussed. In particular, polarized gas targets have been used in the VEPP-3 electron ring in Novosibirsk. A simple storage cell was used to increase the total target thickness by a factor of 15 over the simple gas jet target from an atomic beam source. Results from the initial phase of this project will be reported. In addition, the plans for increasing the luminosity by an additional order or magnitude will be presented. The application of this work to polarized hydrogen and deuterium targets for the HERA ring will be noted. The influence of beam-induced depolarization, a phenomena encountered in short-pulse electron storage rings, will be discussed. Finally, the performance tests of laser-driven sources will be presented. 8 refs., 12 figs., 1 tab

Liquid hydrogen and deuterium targets

International Nuclear Information System (INIS)

Bougon, M.; Marquet, M.; Prugne, P.

1961-01-01

A description is given of 1) Atmospheric pressure target: liquid hydrogen, 400 mm thickness; thermal insulation: styrofoam; the hydrogen vapors are used to improve the target cooling; Mylar windows. 2) Vacuum target: 12 liter content: hydrogen or deuterium; liquid thickness 400 mm; thermal insulation is afforded by a vacuum vessel and a liquid nitrogen shield. Recovery and liquefaction of deuterium vapors are managed in the vacuum vessel which holds the target. The target emptying system is designed for operating in a few minutes. (author) [fr

Liquid hydrogen and deuterium targets; Cibles a hydrogene et deuterium liquides

Energy Technology Data Exchange (ETDEWEB)

Bougon, M; Marquet, M; Prugne, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1961-07-01

A description is given of 1) Atmospheric pressure target: liquid hydrogen, 400 mm thickness; thermal insulation: styrofoam; the hydrogen vapors are used to improve the target cooling; Mylar windows. 2) Vacuum target: 12 liter content: hydrogen or deuterium; liquid thickness 400 mm; thermal insulation is afforded by a vacuum vessel and a liquid nitrogen shield. Recovery and liquefaction of deuterium vapors are managed in the vacuum vessel which holds the target. The target emptying system is designed for operating in a few minutes. (author) [French] Description de: 1) Cible a pression atmospherique; hydrogene liquide, 400 mm d'epaisseur; l'isolement thermique: styrofoam; on utilise les vapeurs d'hydrogene pour ameliorer le refroidissement de la cible; hublots en Mylar. 2) Cible sous vide; contenance 12 litres; hydrogene ou deuterium; epaisseur du liquide 400 mm; l'isolement thermique est assure par une cuve a vide et un ecran d'azote liquide. Recuperation et liquefaction des vapeurs de deuterium sont effectuees dans la cuve a vide contenant la cible. Le systeme de vidange pour la cible est concu pour fonctionner en quelques minutes. (auteur)

Spin-polarized hydrogen, deuterium, and tritium : I

International Nuclear Information System (INIS)

Haugen, M.; Ostgaard, E.

1989-01-01

The ground-state energy of spin-polarized hydrogen, deuterium and tritium is calculated by means of a modified variational lowest order constrained-variation method, and the calculations are done for five different two-body potentials. Spin-polarized H is not self-bound according to our theoretical results for the ground-state binding energy. For spin-polarized D, however, we obtain theoretical results for the ground-state binding energy per particle from -0.4 K at an equilibrium particle density of 0.25 σ -3 or a molar volume of 121 cm 3 /mol to +0.32 K at an equilibrium particle density of 0.21 σ -3 or a molar volume of 142 cm 3 /mol, where σ = 3.69 A (1A = 10 -10 m). It is, therefore, not clear whether spin-polarized deuterium should be self-bound or not. For spin-polarized T, we obtain theoretical results for the ground-state binding energy per particle from -4.73 K at an equilibrium particle density of 0.41 σ -3 or a molar volume of 74 cm 3 /mol to -1.21 K at an equilibrium particle density of 0.28 σ -3 or a molar volume of 109 cm 3 /mol. (Author) 27 refs., 9 figs., tab

PST 2009: XIII International Workshop on Polarized Sources Targets and Polarimetry

Science.gov (United States)

Lenisa, Paolo

2011-05-01

The workshops on polarized sources, targets, and polarimetry are held every two years. In 2009 the meeting took place in Ferrara, Italy, and was organized by the University of Ferrara and INFN. Sessions on Polarized Proton and Deuterium Sources, Polarized Electron Sources, Polarimetry, Polarized Solid Targets, and Polarized Internal Targets, highlighted topics, recent developments, and progress in the field. A session dedicated to Future Facilities provided an overview of a number of new activities in the spin-physics sector at facilities that are currently in the planning stage. Besides presenting a broad overview of polarized ion sources, electron sources, solid and gaseous targets, and their neighbouring fields, the workshop also addressed the application of polarized atoms in applied sciences and medicine that is becoming increasingly important.

A high field optical-pumping spin-exchange polarized deuterium source

International Nuclear Information System (INIS)

Coulter, K.P.; Holt, R.J.; Kinney, E.R.; Kowalczyk, R.S.; Poelker, M.; Potterveld, D.H.; Young, L.; Zeidman, B.; Toporkov, D.

1992-01-01

Recent results from a prototype high field optical-pumping spin-exchange polarized deuterium source are presented. Atomic polarization as high as 62% have been observed with an intensity of 6.3 x 10 17 atoms-sec -1 and 65% dissociation fraction

Summary of the XIII International Workshop on Polarized Sources, Targets and Polarimetry

Science.gov (United States)

Rathmann, F.

2011-01-01

The workshops on polarized sources, targets, and polarimetry are held every two years. The present meeting took place in Ferrara, Italy, and was organized by the University of Ferrara. Sessions on Polarized Proton and Deuterium Sources, Polarized Electron Sources, Polarimetry, Polarized Solid Targets, and Polarized Internal Targets, highlighted topics, recent developments, and progress in the field. A session decicated to Future Facilities provided an overview of a number of new activities in the spin-physics sector at facilities that are currently in the planning stage. Besides presenting a broad overview of polarized ion sources, electron sources, solid and gaseous targets, and their neighboring fields, the workshop also addressed the application of polarized atoms in applied sciences and medicine that is becoming increasingly important.

Fine target of deuterium; Blanco fino de deuterio

Energy Technology Data Exchange (ETDEWEB)

Diaz Diaz, J; Granados Gonzalez, C E; Gutierrez Bernal, R

1959-07-01

A fine target of deuterium on a tantalum plate by the absorption method is obtained. In order to obtain the de gasification temperature an induction generator of high frequency is used and the deuterium pass is regulated by means of a palladium valve. Two vacuum measures are available, one to measure the high vacuum in the de gasification process of the tantalum plate and the other, for low vacuum, to measure the deuterium inlet in the installation and the deuterium pressure change in the installation after the absorption in the tantalum plate. A target of 48 {mu} gr/cm{sup 2} thick is obtained. (Author) 1 refs.

Burn performance of deuterium-tritium, deuterium-deuterium, and catalyzed deuterium ICF targets

International Nuclear Information System (INIS)

Harris, D.B.; Blue, T.E.

1983-01-01

The University of Illinois hydrodynamic burn code, AFBURN, has been used to model the performance of homogeneous D-T, D 2 , and catalyzed deuterium ICF targets. Yields and gains are compared for power-producing targets. AFBURN is a one-dimensional, two-temperature, single-fluid hydrodynamic code with non-local fusion product energy deposition. The initial conditions for AFBURN are uniformly compressed targets with central hot spots. AFBURN predicts that maximum D 2 target gains are obtained for target rhoR and spark rhoR about seven times larger than the target and spark rhoR for maximum D-T target gains, that the maximum D 2 target gain is approximately one third of the maximum D-T target gain, and that the corresponding yields are approximately equal. By recycling tritium and 3 He from previous targets, D 2 target performance can be improved by about 10%. (author)

Absence of molecular deuterium dissociation during room-temperature permeation into polystyrene ICF target shells

International Nuclear Information System (INIS)

Honig, A.; Alexander, N.; Fan, Q.; Gram, R.; Kim, H.

1991-01-01

Polystyrene microshells filled with deuterium and tritium gas are important target shells for inertially confined fusion (ICF) and are particularly promising for target containing spin-polarized hydrogens fuels. A currently active approach to the latter uses polarized D in HD, in a method which requires preservation of the high purity of the initially prepared HD (very low specified H 2 and D 2 concentrations). This would not be possible if dissociation should occur during permeation into the target shells. We have thus tested polystyrene shells using a novel method which employs very pure polystyrene shells using a novel method which employs very pure ortho-D 2 as the test gas. An upper limit of 6 x 10 -4 was deduced for the dissociation of D 2 upon room temperature permeation through an approximately 8 um wall of polystyrene, clearing the way for use of polystyrene target shells for ICF fusion experiments with spin-polarized hydrogens fuels. 19 refs., 1 fig

Status of the hydrogen and deuterium atomic beam polarized target for NEPTUN experiment

International Nuclear Information System (INIS)

Balandikov, N.I.; Ershov, V.P.; Fimushkin, V.V.; Kulikov, M.V.; Pilipenko, Y.K.; Shutov, V.B.

1995-01-01

NEPTUN-NEPTUN-A is a polarized experiment at Accelerating and Storage Complex (UNK, IHEP) with two internal targets. Status of the atomic beam polarized target that is being developed at the Joint Institute for Nuclear Research, Dubna is presented. copyright 1995 American Institute of Physics

Deeply Virtual Compton Scattering off a deuterium target at the HERMES experiment

International Nuclear Information System (INIS)

Movsisyan, Aram

2011-05-01

Deeply virtual Compton scattering is studied in this report, using all data collected at the HERMES experiment from 1996 to 2005. Azimuthal asymmetries with respect to beam-helicity, beam-charge and target polarization alone and also to their different combinations for hard exclusive electroproduction of real photons in deep-inelastic scattering from a both unpolarized and longitudinally polarized deuterium targets are measured. The asymmetries are attributed to the interference between the deeply virtual Compton scattering and Bethe-Heitler processes. The asymmetries are observed in the exclusive region -(1.5) 2 GeV 2 2 X 2 GeV 2 of the squared missing mass. The dependences of these asymmetries on -t, x N , or Q 2 are investigated. The results include the coherent process ed→edγ and the incoherent process ed→epnγ where in addition a nucleon may be excited to a resonance. For an unpolarized deuterium target, the leading Fourier amplitude of the beam-helicity asymmetry that is sensitive to the interference term is found to be substantial, but no significant t dependence is observed. The leading amplitude of the beam-charge asymmetry is substantial at large -t, but becomes small at small values of -t. The amplitudes of the beam-helicity asymmetry that are sensitive to the squared DVCS term are found to be consistent with zero. The deuteron Compton form factor H 1 appears to have a similar behavior as H of the proton. (orig.)

Design of a deuterium and tritium-ablator shock ignition target for the National Ignition Facility

International Nuclear Information System (INIS)

Terry, Matthew R.; Perkins, L. John; Sepke, Scott M.

2012-01-01

Shock ignition presents a viable path to ignition and high gain on the National Ignition Facility (NIF). In this paper, we describe the development of the 1D design of 0.5 MJ class, all-deuterium and tritium (fuel and ablator) shock ignition target that should be reasonably robust to Rayleigh-Taylor fluid instabilities, mistiming, and hot electron preheat. The target assumes “day one” NIF hardware and produces a yield of 31 MJ with reasonable allowances for laser backscatter, absorption efficiency, and polar drive power variation. The energetics of polar drive laser absorption require a beam configuration with half of the NIF quads dedicated to launching the ignitor shock, while the remaining quads drive the target compression. Hydrodynamic scaling of the target suggests that gains of 75 and yields 70 MJ may be possible.

Energy properties of deuterium cluster impacts on TiD targets

International Nuclear Information System (INIS)

Yamamura, Yasunori

1992-01-01

In order to know the energy properties of deuterium atoms in the cluster impact region, the deuterium cluster impact phenomena have been simulated by using the time-evolution Monte Carlo simulation code DYACAT, where the (D) n (n being 100 to 500 ) with energy 500eV/atom are bombarded on TiD targets. For comparison, the energy properties of 500 eV/atom (Al) 500 cluster impacts on amorphous Au targets have also been simulated. In the case of the deuterium cluster impacts on TiD targets, the high energy tail of the energy distribution of deuterium atoms drops so fast. The temperature of the deuterium cluster impact region is less than 100 ev, and it decreases slightly as the cluster size increases due to the enhanced energy removal with reflected deuterium atoms and sputtered deuterium atoms. While in the case of 500 eV/atom (Al) 500 cluster impacts on Au the high-energy tail of the energy distribution of Al atoms due to the big cluster impact can be well described in terms of the Maxwell-Boltzmann function whose temperature is 270 ev. (author)

Deeply Virtual Compton Scattering off a deuterium target at the HERMES experiment

Energy Technology Data Exchange (ETDEWEB)

Movsisyan, Aram

2011-05-15

Deeply virtual Compton scattering is studied in this report, using all data collected at the HERMES experiment from 1996 to 2005. Azimuthal asymmetries with respect to beam-helicity, beam-charge and target polarization alone and also to their different combinations for hard exclusive electroproduction of real photons in deep-inelastic scattering from a both unpolarized and longitudinally polarized deuterium targets are measured. The asymmetries are attributed to the interference between the deeply virtual Compton scattering and Bethe-Heitler processes. The asymmetries are observed in the exclusive region -(1.5){sup 2} GeV{sup 2}deuterium target, the leading Fourier amplitude of the beam-helicity asymmetry that is sensitive to the interference term is found to be substantial, but no significant t dependence is observed. The leading amplitude of the beam-charge asymmetry is substantial at large -t, but becomes small at small values of -t. The amplitudes of the beam-helicity asymmetry that are sensitive to the squared DVCS term are found to be consistent with zero. The deuteron Compton form factor H{sub 1} appears to have a similar behavior as H of the proton. (orig.)

Direct drive acceleration of planar liquid deuterium targets

International Nuclear Information System (INIS)

Sethian, J.D.; Bodner, S.E.; Colombant, D.G.; Dahlburg, J.P.; Obenschain, S.P.; Pawley, C.J.; Serlin, V.; Gardner, J.H.; Aglitskiy, Y.; Chan, Y.; Deniz, A.V.; Lehecka, T.; Klapisch, M.

1999-01-01

The Nike laser (∼2 - 3 kJ, ∼10 14 W/cm 2 ) has been used to ablatively accelerate planar liquid deuterium targets. These experiments are designed to test some aspects of a high gain direct drive target design. The target consists of a low-density foam that is filled with liquid deuterium and covered with a thin polyimide membrane. The measured target trajectory agrees well with one-dimensional (1D) simulations. The growth of the areal mass modulations were measured with a new, 1.26 keV x-ray backlighter. The modulations appear later and grow to a smaller amplitude when the foot of the laser pulse is made spatially smoother. A thin layer of gold on the front of the target reduces the modulations. The results are compared with 2D modeling

Development Of A Hydrogen And Deuterium Polarized Gas Target For Application In Storage Rings

International Nuclear Information System (INIS)

Haeberli, Willy

2009-01-01

The exploration of spin degrees of freedom in nuclear and high-energy interactions requires the use of spin-polarized projectiles and/or spin-polarized targets. During the last two decades, the use of external beams from cyclotrons has to a large extent been supplanted by use of circulating beams stored in storage rings. In these experiments, the circulating particles pass millions of times through targets internal to the ring. Thus the targets need to be very thin to avoid beam loss by scattering out of the acceptance aperture of the ring.

Work of the Liquid Deuterium Target of the Joint Institute for Nuclear Research at the Yerevan Electron Acceleration Ring

CERN Document Server

Golovanov, L B; Panebratsev, Yu A; Tsvinev, A P; Chumakov, V F; Shimansky, S S; Babayan, K Z; Mirzoyan, A E; Movsesyan, G D; Sirunyan, A M

2003-01-01

A cryogenic installation with a target filled with liquid hydrogen (deuterium), developed in the LHE JINR is described. The installation was used in an experimental run at the Yerevan ring accelerator with a beam of polarized photons. A description of the installation, features of its work in the YerPhI and its operational parameters is given.

Laser-driven source of spin-polarized atomic hydrogen and deuterium

International Nuclear Information System (INIS)

Poelker, M.

1995-01-01

A laser-driven source of spin-polarized hydrogen (H) and deuterium (D) that relies on the technique of optical pumping spin exchange has been constructed. In this source, H or D atoms and potassium atoms flow continuously through a drifilm-coated spin-exchange cell where potassium atoms are optically pumped with circularly-polarized laser light in a high magnetic field. The H or D atoms become polarized through spin-exchange collisions with polarized potassium atoms. High electron polarization (∼80%) has been measured for H and D atoms at flow rates ∼2x10 17 atoms/s. Lower polarization values are measured for flow rates exceeding 1x10 18 atoms/s. In this paper, we describe the performance of the laser-driven source as a function of H and D atomic flow rate, magnetic field strength, alkali density and pump-laser power. Polarization measurements as a function of flow rate and magnetic field suggest that, despite a high magnetic field, atoms within the optical-pumping spin-exchange apparatus evolve to spin-temperature equilibrium which results in direct polarization of the H and D nuclei. (orig.)

The control system of the polarized internal target of ANKE at COSY

Energy Technology Data Exchange (ETDEWEB)

Kleines, H. [Zentralinstitut fuer Elektronik, Forschungszentrum Juelich, 52425 Juelich (Germany); Sarkadi, J. [Zentralinstitut fuer Elektronik, Forschungszentrum Juelich, 52425 Juelich (Germany); Zwoll, K. [Zentralinstitut fuer Elektronik, Forschungszentrum Juelich, 52425 Juelich (Germany); Engels, R. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Grigoryev, K. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Mikirtychyants, M. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Nekipelov, M. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Rathmann, F. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Seyfarth, H. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany)]. E-mail: h.seyfarth@fz-juelich.de; Kravtsov, P. [St. Petersburg Nuclear Physics Institute, 188350 Gatchina (Russian Federation); Vasilyev, A. [St. Petersburg Nuclear Physics Institute, 188350 Gatchina (Russian Federation)

2006-05-10

The polarized internal target for the ANKE experiment at the Cooler Synchrotron COSY of the Forschungszentrum Juelich utilizes a polarized atomic beam source to feed a storage cell with polarized hydrogen or deuterium atoms. The nuclear polarization is measured with a Lamb-shift polarimeter. For common control of the two systems, industrial equipment was selected providing reliable, long-term support and remote control of the target as well as measurement and optimization of its operating parameters. The interlock system has been implemented on the basis of SIEMENS SIMATIC S7-300 family of programmable logic controllers. In order to unify the interfacing to the control computer, all front-end equipment is connected via the PROFIBUS DP fieldbus. The process control software was implemented using the Windows-based WinCC toolkit from SIEMENS. The variety of components, to be controlled, and the logical structure of the control and interlock system are described. Finally, a number of applications derived from the present development to other, new installations are briefly mentioned.

The control system of the polarized internal target of ANKE at COSY

Science.gov (United States)

Kleines, H.; Sarkadi, J.; Zwoll, K.; Engels, R.; Grigoryev, K.; Mikirtychyants, M.; Nekipelov, M.; Rathmann, F.; Seyfarth, H.; Kravtsov, P.; Vasilyev, A.

2006-05-01

The polarized internal target for the ANKE experiment at the Cooler Synchrotron COSY of the Forschungszentrum Jülich utilizes a polarized atomic beam source to feed a storage cell with polarized hydrogen or deuterium atoms. The nuclear polarization is measured with a Lamb-shift polarimeter. For common control of the two systems, industrial equipment was selected providing reliable, long-term support and remote control of the target as well as measurement and optimization of its operating parameters. The interlock system has been implemented on the basis of SIEMENS SIMATIC S7-300 family of programmable logic controllers. In order to unify the interfacing to the control computer, all front-end equipment is connected via the PROFIBUS DP fieldbus. The process control software was implemented using the Windows-based WinCC toolkit from SIEMENS. The variety of components, to be controlled, and the logical structure of the control and interlock system are described. Finally, a number of applications derived from the present development to other, new installations are briefly mentioned.

Polarization measurement for internal polarized gaseous targets

International Nuclear Information System (INIS)

Ye Zhenyu; Ye Yunxiu; Lv Haijiang; Mao Yajun

2004-01-01

The authors present an introduction to internal polarized gaseous targets, polarization method, polarization measurement method and procedure. To get the total nuclear polarization of hydrogen atoms (including the polarization of the recombined hydrogen molecules) in the target cell, authors have measured the parameters relating to atomic polarization and polarized hydrogen atoms and molecules. The total polarization of the target during our measurement is P T =0.853 ± 0.036. (authors)

New directions in the theory of spin-polarized atomic hydrogen and deuterium

International Nuclear Information System (INIS)

Koelman, J.M.V.A.

1988-01-01

The three chapters of this thesis dealing with collisions between hydrogen (or deuterium) atoms in their ground state, each treat a different development in the theory of atomic hydrogen or deuterium gas. The decay due to interatomic collisions hindered till now all attempts to reach the low temperature, high-density regime where effects due to degeneracy are expected to show up. In ch. 2 a simple way out is presented for the case of Fermi gases: In spin-polarized Fermi systems at very low temperatures collisions are much effective than in Bose systems. For the Fermi gas, consisting of magnetically confined deuterium atoms, it appears that fast spin-exchange collisions automatically lead to a completely spin-polarized gas for which the spin-relaxation limited lifetime increases dramatically with decreasing temperature. As also the ratio of internal thermalization rate over decay rate increases with decreasing temperature, this gas can be cooled by forced evaporation down to very low temperatures. In ch. 3 it iis shown that the nuclear spin dynamics due to the hyperfine interaction during collisions, strongly limits the improvement in frequency stability attainable by H masers operating at low temperatures. In ch. 4 the phenomenon of spin waves is studied. It is shown that, despite the fact that interactions between two atoms are nuclear-spin independent, the outcome of a scattering event does not depend on the nuclear spins involved due to the particle indistinguishability effects at low collision energies. This effect gives rise to quantum phenomena on a macroscopic scale via the occurrence of spin waves. (author). 185 refs.; 34 figs

Remote Monitoring of the Polarized Target's Control for E1039

Science.gov (United States)

Fox, David; SeaQuest Collaboration

2017-09-01

The 1039 experiment at FNAL will further our understanding of spin structure by measuring the contribution that sea quarks orbital angular momentum provide to overall nucleon spin. It is accepted that the valence-quarks of nucleons only provide 30% of the total nucleon spin. To study the nucleon's sea quark contribution, E1039 will use the Drell-Yan process by colliding 120 GeV un-polarized beam protons with polarized ammonia targets of hydrogen and deuterium. The asymmetric spin distributions of resulting dimuons will be measured. These asymmetries are sensitive, among other effects, to the orbital angular momentum contribution of the sea quarks. The polarized target requires a multi-stage vacuum pump located near the target. Since access to its present controls will not be possible during running, remote control and monitoring upgrades were required. A secondary control panel was purchased and tested. Information from the programmable logic controller (PLC) must be fed into our data stream to enable remote monitoring and to signal possible alarm conditions. This solution and the program created using explicit TCP/IP messaging to extract data tags from the PLC and log it within our databases will be presented. Supported by U.S. D.O.E. Medium Energy Nuclear Physics under Grant DE-FG02-03ER41243.

Polarized targets and beams

International Nuclear Information System (INIS)

Meyer, W.

1985-01-01

First the experimental situation of the single-pion photoproduction and the photodisintegration of the deuteron is briefly discussed. Then a description of the Bonn polarization facilities is given. The point of main effort is put on the polarized target which plays a vital role in the program. A facility for photon induced double polarization experiments at ELSA will be presented in section 4. Properties of a tensor polarized deuteron target are discussed in section 5. The development in the field of polarized targets, especially on new target materials, enables a new generation of polarized target experiments with (polarized) electrons. Some comments on the use of a polarized target in combination with electron beams will be discussed in section 6. Electron deuteron scattering from a tensor polarized deuteron target is considered and compared with other experimental possibilities. (orig./HSI)

A search for parity violation in the inelastic scattering of polarized electrons from deuterium at 19.4 GeV

International Nuclear Information System (INIS)

Prescott, C.Y.; Atwood, W.B.; Cottrell, R.L.A.

1977-01-01

A search for parity violating effects in the inelastic scattering of polarized electrons off an unpolarized deuterium target at 19.4 GeV has recently been performed at SLAC. Using the 20-GeV/c and 8-GeV/c spectrometers, two kinematical points with Q 2 values of 1.2 GeV/c 2 and 4.2 GeV/c 2 , respectively, have been measured. Statistical accuracy of the measurements approaches the level of the weak interactions. Systematic errors are still being studied. Techniques to measure and control systematic errors and the present status of the data analysis are discussed

Design of a cryogenic deuterium gas target for neutron therapy

International Nuclear Information System (INIS)

Kuchnir, F.T.; Waterman, F.M.; Forsthoff, H.; Skaggs, L.S.; Vander Arend, P.C.; Stoy, S.

1976-01-01

A cryogenic deuterium gas target operating at 80 0 K and 10 atm pressure has been designed for use with a small cyclotron; the D(d,n) reaction is used to produce a neutron beam suitable for radiation therapy. The target is cooled by circulation of the gas in a closed loop between the target and an external heat exchanger immersed in liquid nitrogen

A laser driven source of spin polarized atomic hydrogen and deuterium

International Nuclear Information System (INIS)

Poelker, M.; Coulter, K.P.; Holt, R.J.; Jones, C.E.; Kowalczyk, R.S.; Young, L.; Toporkov, D.

1993-01-01

Recent results from a laser-driven source of polarized hydrogen (H) and deuterium (D) are presented. The performance of the source is described as a function of atomic flow rate and magnetic field. The data suggest that because atomic densities in the source are high, the system can approach spin-temperature equilibrium although applied magnetic fields are much larger than the critical field of the atoms. The authors also observe that potassium contamination in the source emittance can be reduced to a negligible amount using a teflon-lined transport tube

Measurements of the spin structure of the nucleon using SPHICE: A strongly polarized hydrogen and deuterium ice target

International Nuclear Information System (INIS)

Babusci, D.; Blecher, M.; Breuer, M.; Caracappa, A.; Commeaux, C.; Didelez, J.; Fan, Q.; Giordano, G.; Hicks, K.; Hoblit, S.; Hoffmann-Rothe, P.; Honig, A.; Kistner, O.C.; Khandaker, M.; Li, Z.; Lucas, M.A.; Matone, G.; Miceli, L.; Preedom, B.M.; Rigney, M.; Sandorfi, A.M.; Schaerf, C.; Thorn, C.E.

1995-01-01

Frozen-spin HD polarized targets operating between 0.4 and 4K, used with cold-transfer (4K) techniques, provide great configurational flexibility. Their long depolarization times under target usage conditions assure reasonable match between polarization production and usage times, for weakly ionizing beam fluxes, and the very long relaxation times at fields above 7T (∼1 yr.) provide an economical storage mode and open-quote open-quote off-the-shelf close-quote close-quote availability. copyright 1995 American Institute of Physics

Polarized nuclear target based on parahydrogen induced polarization

OpenAIRE

Budker, D.; Ledbetter, M. P.; Appelt, S.; Bouchard, L. S.; Wojtsekhowski, B.

2012-01-01

We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast ($\\sim$100 Hz) polarization reversal, and operation with large intensity of an electron beam.

Polarized semi-inclusive deep-inelastic scattering on transversely and longitudinally polarized nucleons at HERMES

International Nuclear Information System (INIS)

Hommes, B.

2005-01-01

The HERMES experiment has measured double spin asymmetries in the cross section for deep-inelastic scattering of longitudinal polarized positrons off longitudinal polarized hydrogen and deuterium targets. From these asymmetries, based on inclusive and semi-inclusive measurements, polarized quark distributions were extracted as a function of x. Single-spin azimuthal asymmetries in semi-inclusive pion production were measured by the HERMES experiment for the first time, with a transversely polarized hydrogen target. Two different sine-dependencies were extracted which can be related to the quark transversity distribution h q 1 (x) and the Sivers function (Author)

Accelerator-based neutron source using a cold deuterium target with degenerate electrons

Directory of Open Access Journals (Sweden)

R. E. Phillips

2013-07-01

Full Text Available A neutron generator is considered in which a beam of tritons is incident on a hypothetical cold deuterium target with degenerate electrons. The energy efficiency of neutron generation is found to increase substantially with electron density. Recent reports of potential targets are discussed.

Characterization of a deuterium-deuterium plasma fusion neutron generator

Science.gov (United States)

Lang, R. F.; Pienaar, J.; Hogenbirk, E.; Masson, D.; Nolte, R.; Zimbal, A.; Röttger, S.; Benabderrahmane, M. L.; Bruno, G.

2018-01-01

We characterize the neutron output of a deuterium-deuterium plasma fusion neutron generator, model 35-DD-W-S, manufactured by NSD/Gradel-Fusion. The measured energy spectrum is found to be dominated by neutron peaks at 2.2 MeV and 2.7 MeV. A detailed GEANT4 simulation accurately reproduces the measured energy spectrum and confirms our understanding of the fusion process in this generator. Additionally, a contribution of 14 . 1 MeV neutrons from deuterium-tritium fusion is found at a level of 3 . 5%, from tritium produced in previous deuterium-deuterium reactions. We have measured both the absolute neutron flux as well as its relative variation on the operational parameters of the generator. We find the flux to be proportional to voltage V 3 . 32 ± 0 . 14 and current I 0 . 97 ± 0 . 01. Further, we have measured the angular dependence of the neutron emission with respect to the polar angle. We conclude that it is well described by isotropic production of neutrons within the cathode field cage.

Stanford polarized atomic beam target

International Nuclear Information System (INIS)

Mavis, D.G.; Dunham, J.S.; Hugg, J.W.; Glavish, H.F.

1976-01-01

A polarized atomic beam source was used to produce an atomic hydrogen beam which was in turn used as a polarized proton target. A target density of 2 x 10'' atoms/cm 3 and a target polarization of 0.37 without the use of rf transitions were measured. These measurements indicate that a number of experiments are currently feasible with a variety of polarized target beams

Polarization and molar volumes of ortho- and para-deuterium solutions

International Nuclear Information System (INIS)

Milenko, Yu.Ya.; Sibileva, R.M.

1976-01-01

The dielectric constant of liquid solutions of ortho-and para-deuterium is measured over the range of 2.2-91% p-D 2 from 18.7 to 20.4deg K. Data on polarization and molar volumes are obtained for the whole (0-100%) concentration range. Corrected summary to paper [2] is also listed: dielectric constant of ortho- and para-hydrogen liquid solution is measured within a concentration range of 0-97% of o-molecules at 14-20.4deg K. It is established that dependence of the Clausius-Mossotti function for o-p-hydrogen solutions of o-p-composition is linear. Molar volumes of the o-p-mixtures are calculated. The excessive molar volumes are found, positive deviation from additivity, 0.15% is established

Neutron polarization in polarized 3He targets

International Nuclear Information System (INIS)

Friar, J.L.; Gibson, B.F.; Payne, G.L.; Bernstein, A.M.; Chupp, T.E.

1990-01-01

Simple formulas for the neutron and proton polarizations in polarized 3 He targets are derived assuming (1) quasielastic final states; (2) no final-state interactions; (3) no meson-exchange currents; (4) large momentum transfers; (5) factorizability of 3 He SU(4) response-function components. Numerical results from a wide variety of bound-state solutions of the Faddeev equations are presented. It is found that this simple model predicts the polarization of neutrons in a fully polarized 3 He target to be 87%, while protons should have a slight residual polarization of -2.7%. Numerical studies show that this model works very well for quasielastic electron scattering

Review of polarized ammonium target

International Nuclear Information System (INIS)

Matsuda, Tatsuo

1987-01-01

Recently, ammonia (NH 3 ) and deutron ammonia (ND 3 ), instead of conventional alcohol substances, have been used more frequently as a polarized target substance for experiments of polarization at high energy regions. This article reviews major features of the polarized (deutron) ammonia targets. The dynamic nuclear polarization (DNT) method is widely used in high energy polarization experiments. While only a low polarization degree of hydrogen nucleus of 1.7 percent can be obtained by the Brute force method, DNP can produce polarization as high as ∼ 90 percent (2.5 T, ∼ 200 mK). In 1979, ammonia was irradiated with radiations to form NH 2 free radicals, resulting in the achievement of a high polarization degree of greater than 90 percent (hydrogen). Since then, ammonia and deutron ammonia have increasingly been replacing alcohols including butanol. Irradiation of a target substance with radiations destroys the structure of the substance, leading to a decrease in polarization degree. However, ammonia produces unpaired electrons as a result of irradiation, allowing it to be highly resistant to radiation. This report also present some study results, including observations on effects of radiation on the polarization degree of a target, effects of annealing, and polarization of 14 N. A process for producing an ammonia target is also described. (Nogami, K.)

Fusion of a polarized projectile with a polarized target

International Nuclear Information System (INIS)

Christley, J.A.; Johnson, R.C.; Thompson, I.J.

1995-01-01

The fusion cross sections for a polarized target with both unpolarized and polarized projectiles are studied. Expressions for the observables are given for the case when both nuclei are polarized. Calculations for fusion of an aligned 165 Ho target with 16 O and polarized 7 Li beams are presented

A spin-filter polarimeter for low energy hydrogen and deuterium ion beams

International Nuclear Information System (INIS)

Lemieux, S.K.; Clegg, T.B.; Karwowski, H.J.; Thompson, W.J.; Crosson, E.R.

1993-01-01

An efficient polarimeter which reveals populations of individual hyperfine states of nuclear-spin-polarized H ± (or D ± ) ion beams has been tested. This device is based on unique properties of a three-level interaction in the 2S 1/2 and 2P 1/2 states of hydrogen (or deuterium) atoms, created when the incident, polarized ion beams undergo electron pickup in cesium vapour. Used on a polarized ion source, its efficiency faciy facilitates both rapid optimization and continual monitoring of parameters that affect the beam polarization. With such sources, and perhaps in applications with polarized gas jet targets, the device has potential for an absolute accuracy of better than 2%. (orig.)

Energy cost of negative pion production on deuterium-tritium target

Energy Technology Data Exchange (ETDEWEB)

Kuzminov, V.V. (Petersburg Nuclear Physics Inst., Gatchina, St. Petersburg (Russian Federation)); Petrov, Yu.V. (Petersburg Nuclear Physics Inst., Gatchina, St. Petersburg (Russian Federation)); Shabelski, Yu.M. (Petersburg Nuclear Physics Inst., Gatchina, St. Petersburg (Russian Federation))

1993-12-01

The negative pion production by deuterons (T[sub 0] = 0.8 GeV/nucl.) was calculated for a cylindrical gaseous deuterium-tritium target (the density of DT-mixture is [phi] = 0.5). Revised cross sections of nucleon-nucleus interaction were used in a Monte Carlo simulation and multiple nucleon-nuclei collisions were taken into account. The energy cost of negative pion production is [epsilon][sub [pi][sup -

Deuterium NMR, induced and intrinsic cholesteric lyomesophases

International Nuclear Information System (INIS)

Alcantara, M.R.

1982-01-01

Induced and intrinsic cholesteric lyotropic mesophases were studied. Induced cholesteric lyomesophases based on potassium laurate (KL) system, with small amounts of cholesterol added, were studied by deuterium NMR and by polarizing microscopy. Order profiles obtained from deuterium NMR of KL perdenderated chains in both induced cholesteric and normal mesophases were compared. The intrinsic cholesteric lyotropic mesophases were based on the amphiphile potassium N-lauroyl serinate (KLNS) in the resolved levo form. The study of the type I intrinsic cholesteric mesophase was made by optical microscopy under polarized light and the type II intrinsic cholesteric lyomesophase was characterized by deuterium NMR. The new texture was explained by the use of the theory of disclinations developed for thermotropic liquid crystals, specially for cholesteric type. (M.J.C.) [pt

System for measuring the proton polarization in a polarized target

International Nuclear Information System (INIS)

Karnaukhov, I.M.; Lukhanin, A.A.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

1984-01-01

The system for measuring the proton polarization in a polarized target representing the high-sensitivity nuclear magnetic resonance (NMR) is described Q-meter with series connection and a circuit for measuring system resonance characteristic is used for NMR-absorption signal recording. Measuring coil is produced of a strip conductor in order to obtain uniform system sensitivity to polarization state in all target volume and improve signal-to-noise ratio. Polarization measuring system operates ion-line with the M-6000 computer. The total measuring error for the value of free proton polarization in target taking into account the error caused by local depolarization of working substance under irradiation by high-intense photon beam is <= 6%. Long-term application of the described system for measuring the proton polarization in the LUEh-20000 accelerator target used in the pion photoproduction experiments has demonstrated its high reliability

Dynamic nuclear polarization of irradiated target materials

International Nuclear Information System (INIS)

Seely, M.L.

1982-01-01

Polarized nucleon targets used in high energy physics experiments usually employ the method of dynamic nuclear polarization (DNP) to polarize the protons or deuterons in an alcohol. DNP requires the presence of paramagnetic centers, which are customarily provided by a chemical dopant. These chemically doped targets have a relatively low polarizable nucleon content and suffer from loss of polarization when subjected to high doses of ionizing radiation. If the paramagnetic centers formed when the target is irradiated can be used in the DNP process, it becomes possible to produce targets using materials which have a relatively high polarizable nucleon content, but which are not easily doped by chemical means. Furthermore, the polarization of such targets may be much more radiation resistant. Dynamic nuclear polarization in ammonia, deuterated ammonia, ammonium hydroxide, methylamine, borane ammonia, butonal, ethane and lithium borohydride has been studied. These studies were conducted at the Stanford Linear Accelerator Center using the Yale-SLAC polarized target system. Results indicate that the use of ammonia and deuterated ammonia as polarized target materials would make significant increases in polarized target performance possible

The Bochum Polarized Target

International Nuclear Information System (INIS)

Reicherz, G.; Goertz, S.; Harmsen, J.; Heckmann, J.; Meier, A.; Meyer, W.; Radtke, E.

2001-01-01

The Bochum 'Polarized Target' group develops the target material 6 LiD for the COMPASS experiment at CERN. Several different materials like alcohols, alcanes and ammonia are under investigation. Solid State Targets are polarized in magnetic fields higher than B=2.5T and at temperatures below T=1K. For the Dynamic Nuclear Polarization process, paramagnetic centers are induced chemically or by irradiation with ionizing beams. The radical density is a critical factor for optimization of polarization and relaxation times at adequate magnetic fields and temperatures. In a high sensitive EPR--apparatus, an evaporator and a dilution cryostat with a continuous wave NMR--system, the materials are investigated and optimized. To improve the polarization measurement, the Liverpool NMR-box is modified by exchanging the fixed capacitor for a varicap diode which not only makes the tuning very easy but also provides a continuously tuned circuit. The dependence of the signal area upon the circuit current is measured and it is shown that it follows a linear function

Hot muonic deuterium and tritium from cold targets

International Nuclear Information System (INIS)

Marshall, G.M.; Beveridge, J.L.; Bailey, J.M.; Beer, G.A.; Knowles, P.E.; Mason, G.R.; Olin, A.; Brewer, J.H.; Forster, B.M.; Huber, T.M.; Pippitt, B.; Jacot-Guillarmod, R.; Schellenberg, L.; Martoff, C.J.; Petitjean, C.

1992-01-01

Experiments are described which use a solid hydrogen layer to form muonic hydrogen isotopes in vacuum. The method relies on transfer of the muon from protium to either a deuteron or a triton. The resulting muonic deuterium or muonic tritium will not immediately thermalize because of the very low elastic cross sections, and may be emitted from the surface of the layer. Measurements which detect decay electrons, muonic x-rays, and fusion products have been used to study the processes. A target has been constructed which exploits muonic atom emission in order to study the energy dependence of transfer and muon molecular formation

Polarized targets in high energy physics

Energy Technology Data Exchange (ETDEWEB)

Cates, G.D. Jr. [Princeton Univ., NJ (United States)

1994-12-01

Various approaches are discussed for producing polarized nuclear targets for high energy physics experiments. As a unifying theme, examples are drawn from experiments to measure spin dependent structure functions of nucleons in deep inelastic scattering. This single physics goal has, over roughly two decades, been a driving force in advances in target technology. Actual or planned approaches have included solid targets polarized by dynamic nuclear polarization (DNP), several types of internal targets for use in storage rings, and gaseous {sup 3}He targets polarized by spin-exchange optical pumping. This last approach is the type of target adopted for SLAC E-142, an experiment to measure the spin structure function of the neutron, and is described in detail.

Polarized targets in high energy physics

International Nuclear Information System (INIS)

Cates, G.D. Jr.

1994-01-01

Various approaches are discussed for producing polarized nuclear targets for high energy physics experiments. As a unifying theme, examples are drawn from experiments to measure spin dependent structure functions of nucleons in deep inelastic scattering. This single physics goal has, over roughly two decades, been a driving force in advances in target technology. Actual or planned approaches have included solid targets polarized by dynamic nuclear polarization (DNP), several types of internal targets for use in storage rings, and gaseous 3 He targets polarized by spin-exchange optical pumping. This last approach is the type of target adopted for SLAC E-142, an experiment to measure the spin structure function of the neutron, and is described in detail

On the large COMPASS polarized deuteron target

CERN Document Server

Finger, M; Baum, G; Doshita, N; Finger, M Jr; Gautheron, F; Goertz, St; Hasegawa, T; Heckmann, J; Hess, Ch; Horikawa, N; Ishimoto, S; Iwata, T; Kisselev, Y; Koivuniemi, J; Kondo, K; Le Goff, J-M; Magnon, A; Marchand, C; Matsuda, T; Meyer, W; Reicherz, G; Srnka, A

2006-01-01

The spin structure of the nucleons is investigated in deep inelastic scattering of a polarized muon beam and a polarized nucleon target in the COMPASS experiment at CERN since 2001. To achieve high luminosities a large solid polarized target is used. The COMPASS polarized target consists of a high cooling power $^{3}$He/$^{4}$He dilution refrigerator capable to maintain working temperature of the target material at about 50mK, a superconducting solenoid and dipole magnet system for longitudinal and transversal magnetic field on the target material, respectively, target cells containing polarizable material, microwave cavities and high power microwave radiation systems for dynamic nuclear polarization and the nuclear magnetic resonance system for nuclear spin polarization measurements. During 2001–2004 experiments superconducting magnet system with opening angle $\\pm$69 mrad, polarized target holder with two target cells and corresponding microwave and NMR systems have been used. For the data taking from 200...

Optimization of a liquid hydrogen/deuterium target with extremely thin foil windows

International Nuclear Information System (INIS)

Nake, C.J.

1993-09-01

For external experiments at COSY a target of liquid hydrogen or deuterium has been developed, which is very small in order to take advantage of the excellent beam quality of COSY. Targets with thicknesses down to only mm's have been built and operate without bubbles. In order to make the effects of reactions in the windows much smaller than the target reactions, windows with a thickness of about 1.5 μm have been achieved. A novel system which stabilizes the pressure difference between the inside and the outside of the target cell to a small constant value under all target conditions is used. (orig.)

Thin film coatings which inhibit spin relaxation of polarized potassium atoms

International Nuclear Information System (INIS)

Thomas, G.E.; Holt, R.J.; Boyer, D.; Green, M.C.; Kowalczyk, R.S.; Young, L.

1986-01-01

A prototype of a polarized deuterium target which employs the spin exchange method is being developed. The mixing cell for mixing deuterium atoms and potassium vapor requires a surface that will reflect these atoms without being destroyed by the corrosive potassium. Thin film coating methods and a technique for coating pyrex are described. Results of spin relaxation measurements are given

Polarized targets at triangle universities nuclear laboratory

Energy Technology Data Exchange (ETDEWEB)

Seely, M.L. [North Carolina State Univ., Raleigh, NC (United States); Gould, C.R. [North Carolina State Univ., Raleigh, NC (United States); Haase, D.G. [North Carolina State Univ., Raleigh, NC (United States); Huffman, P.R. [Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Keith, C.D. [North Carolina State Univ., Raleigh, NC (United States); Roberson, N.R. [Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Tornow, W. [Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Wilburn, W.S. [Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States)

1995-03-01

A summary of the polarized and aligned nuclear targets which have been constructed and used at the Triangle Universities Nuclear Laboratory is given. Statically polarized targets, typically operating at a temperature of 12 mK and a magnetic field of 7 T, have provided significant nuclear polarization in {sup 1}H, {sup 3}He, {sup 27}Al, {sup 93}Nb and {sup 165}Ho. A rotating, aligned {sup 165}Ho target is also in use. A {sup 3}He melting curve thermometer has been developed for use in statically polarized targets. A dynamically polarized proton target is under construction. ((orig.))

Physics with polarized electrons and targets

International Nuclear Information System (INIS)

Donnelly, T.W.

1984-01-01

With the advent of electron stretcher or storage rings electron scattering from polarized targets becomes a general new tool for nuclear structure studies. Without such facilities it is necessary to have very dense polarized targets for use with the typical (less or approximately equal 50 μA) electron beams available and very few measurements of this type have been attempted. On the other hand, with electron rings the effective circulating current can be greatly increased. In this case much thinner internal targets may be used while still maintaining the same luminosity as in external beam experiments. In ancticipation of such new experimental capabilities we have re-developed the theoretical basis for discussions of electron scattering from polarized targets using either unpolarized or polarized electron beams. This work takes the formalism of unpolarized (e,e') and extends it in a straightforward way to include general polarizations of electrons, target nuclei, recoil nuclei or any combinations of these polarizations. In the present context it is only possible to provide a brief summary of the general form of the cross section and to present a few illustrative examples of the nuclear structure information that may be extracted from such polarization measurements

Solid Polarized Targets and Applications

International Nuclear Information System (INIS)

Crabb, D. G.

2008-01-01

Examples are given of dynamically polarized targets in use today and how the subsystems have changed to meet the needs of todays experiments. Particular emphasis is placed on target materials such as ammonia and lithium deuteride. Recent polarization studies of irradiated materials such as butanol, deuterated butanol, polyethylene, and deuterated polyethylene are presented. The operation of two non-DNP target systems as well as applications of traditional DNP targets are briefly discussed

Polarized target physics at the Bonn electron accelerators

International Nuclear Information System (INIS)

Meyer, W.

1988-12-01

At the BONN 2.5 GeV electron synchrotron experiments with polarized nucleon targets have a long tradition. Starting with measurements of the target asymmetry in single pion photoproduction off polarized protons, resp. neutrons, the experiments have been concentrated on photodisintegration measurements of polarized deuterons. Parallel to these activities a considerable progress in the field of the target technology, e.g. cryogenics and target materials, has been made, by which all the measurements have profitted enormously. Especially the development of the new target material ammonia has allowed the first use of a polarized deuteron (ND 3 ) target in an intense electron beam. The construction of a frozen spin target, which will be used in combination with a tagged polarized photon beam, makes a new generation of polarized target experiments in photon induced reactions possible. Together with electron scattering off polarized deuterons and neutrons they will be a main activity in the physics program at the new stretcher accelerator ELSA in BONN. (orig.)

The polarized double cell target of the SMC

International Nuclear Information System (INIS)

Adams, D.; Adeva, B.; Arik, E.; Arvidson, A.; Badelek, B.; Ballintijn, M.K.; Bardin, G.; Baum, G.; Berglund, P.; Betev, L.; Bird, I.G.; Birsa, R.; Bjoerkholm, P.; Bonner, B.E.; Botton, N. de; Boutemeur, M.; Bradamante, F.; Bravar, A.; Bressan, A.; Bueltmann, S.; Burtin, E.; Cavata, C.; Crabb, D.; Cranshaw, J.; Cuhadar, T.; Torre, S. Dalla; Dantzig, R. van; Derro, B.; Deshpande, A.; Dhawan, S.; Dulya, C.; Dyring, A.; Eichblatt, S.; Faivre, J.C.; Fasching, D.; Feinstein, F.; Fernandez, C.; Forthmann, S.; Frois, B.; Gallas, A.; Garzon, J.A.; Gaussiran, T.; Gilly, H.; Giorgi, M.; Goeler, E. von; Goertz, S.; Gracia, G.; Groot, N. de; Perdekamp, M. Grosse; Guelmez, E.; Haft, K.; Harrach, D. von; Hasegawa, T.; Hautle, P.; Hayashi, N.; Heusch, C.A.; Horikawa, N.; Hughes, V.W.; Igo, G.; Ishimoto, S.; Iwata, T.; Kabuss, E.M.; Kageya, T.; Karev, A.; Kessler, H.J.; Ketel, T.J.; Kiryluk, J.; Kishi, A.; Kisselev, Yu.; Klostermann, L.; Kraemer, D.; Krivokhijine, V.; Kroeger, W.; Kurek, K.; Kyynaeraeinen, J.; Lamanna, M.; Landgraf, U.; Layda, T.; Le Goff, J.M.; Lehar, F.; Lesquen, A. de; Lichtenstadt, J.; Lindqvist, T.; Litmaath, M.; Lowe, M.; Magnon, A.; Mallot, G.K.; Marie, F.; Martin, A.; Martino, J.; Matsuda, T.; Mayes, B.; McCarthy, J.S.; Medved, K.; Meyer, W.; Middelkoop, G. van; Miller, D.; Miyachi, Y.; Mori, K.; Moromisato, J.; Nassalski, J.; Naumann, L.; Neganov, B.; Niinikoski, T.O.; Oberski, J.E.J.; Ogawa, A.; Ozben, C.; Parks, D.P.; Pereira, H.; Penzo, A.; Perrot-Kunne, F.; Peshekhonov, D.; Piegaia, R.; Pinsky, L.; Platchkov, S.; Plo, M.; Pose, D.; Postma, H.; Pretz, J.; Pussieux, T.; Pyrlik, J.; Raedel, G.; Reyhancan, I.; Reicherz, G.; Rieubland, J.M.; Rijllart, A.; Roberts, J.B.; Rock, S.; Rodriguez, M.; Rondio, E.; Rosado, A.; Roscherr, B.; Sabo, I.; Saborido, J.; Sandacz, A.; Savin, I.; Schiavon, P.; Schiller, A.; Schueler, K.P.; Segel, R.; Seitz, R.; Semertzidis, Y.; Sever, F.; Shanahan, P.; Sichtermann, E.P.; Simeoni, F.; Smirnov, G.I.; Staude, A.; Steinmetz, A.; Stiegler, U.; Stuhrmann, H.; Szleper, M.; Teichert, K.M.; Tessarotto, F.; Thers, D.; Tlaczala, W.; Trentalange, S.; Tripet, A.; Unel, G.; Velasco, M.; Vogt, J.; Voss, R.; Weinstein, R.; Whitten, C.; Windmolders, R.; Willumeit, R.; Wislicki, W.; Witzmann, A.; Zanetti, A.M.; Zaremba, K.; Zhao, J.

1999-01-01

The polarized target of the Spin Muon Collaboration at CERN was used for deep inelastic muon scattering experiments during 1993-1996 with a polarized muon beam to investigate the spin structure of the nucleon. Most of the experiments were carried out with longitudinal target polarization and 190 GeV muons, and some were done with transverse polarization and 100 GeV muons. Protons as well as deuterons were polarized by dynamic nuclear polarization (DNP) in three kinds of solid materials -- butanol, ammonia, and deuterated butanol -- with maximum degrees of polarization of 94%, 91% and 60%, respectively. Considerable attention was paid to the accuracies of the NMR polarization measurements and their analyses, the accuracies achieved were between 2.0% and 3.2%. The SMC target system with two cells of opposite polarizations, each cell 65 cm long and 5 cm in diameter, constitutes the largest polarized target system ever built and facilitates accurate spin asymmetry measurements. The design considerations, construction and performance of the target are reviewed

System for measuring of proton polarization in polarized target

International Nuclear Information System (INIS)

Derkach, A.Ya.; Lukhanin, A.A.; Karnaukhov, I.M.; Kuz'menko, V.S.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

1981-01-01

Measurement system of proton polarization in the target, which uses the method of nuclear magnetic resonance is described. To record the signal of NMR-absorption a parallel Q-meter of voltage with analogous subtraction of resonance characteristics of measurement circuit is used. To obtain gradual sensitivity of the system to polarization state in the whole volume of the target the measurement coils is made of tape conductor. The analysis and mathematical modelling of Q-meter are carried out. Corrections for nonlinearity and dispersion are calculated. Key diagrams of the main electron blocks of Q-meter are presented. The system described operates on line with the M6000 computer. Total error of measurement of polarization value of free protons in the target does not exceed 6% [ru

Carbon and deuterium nuclear magnetic resonance in solids

Energy Technology Data Exchange (ETDEWEB)

Shattuck, Thomas Wayne [Univ. of California, Berkeley, CA (United States)

1976-07-01

In Chapter I we present the results on a study of cross polarization dynamics, between protons and carbon-13 in adamantane, by the direct observation of the dilute, carbon-13, spins. These dynamics are an important consideration in the efficiency of proton enhancement double-resonance techniques and they also provide good experimental models for statistical theories of cross relaxation. In order to test these theories we present a comparison of the experimental and theoretical proton dipolar fluctuation correlation time τ_c, which is experimentally 110 ± 15 μsec and theoretically 122 μsec for adamantane. These double resonance considerations provide the background for extensions to deuterium and double quantum effects discussed in Chapter II. In Chapter II an approach to high resolution nmr of deuterium in solids is described. The m = 1 → -1 transition is excited by a double quantum process and the decay of coherence Q(τ) is monitored. Fourier transformation yields a deuterium spectrum devoid of quadrupole splittings and broadening. If the deuterium nuclei are dilute and the protons are spin decoupled, the double-quantum spectrum is a high resolution one and yields information on the deuterium chemical shifts Δω. The relationship Q(τ) ~ cos 2Δωτ is checked and the technique is applied to a single crystal of oxalic acid dihydrate enriched to ~ 10% in deuterium. The carboxyl and the water deuterium shifts are indeed resolved and the anisotropy of the carboxyl shielding tensor is estimated to be Δσ = 32 ± 3 ppm. A complete theoretical analysis is presented. The extension of cross relaxation techniques, both direct and indirect, to proton-deuterium double resonance is also described. The m = 1 → -1 double quantum transition and the m = ± 1 → 0 single quantum transitions may all be polarized and we present the derivation of the Hartmann-Hahn cross polarization conditions for each case. In addition the dynamics of the double quantum process

Development of high pressure deuterium gas targets for the generation of intense mono-energetic fast neutron beams

International Nuclear Information System (INIS)

Guzek, J.; Richardson, K.; Franklyn, C.B.; Waites, A.; McMurray, W.R.; Watterson, J.I.W.; Tapper, U.A.S.

1999-01-01

Two different technical solutions to the problem of generation of mono-energetic fast neutron beams on the gaseous targets are presented here. A simple and cost-effective design of a cooled windowed gas target system is described in the first part of this paper. It utilises a thin metallic foil window and circulating deuterium gas cooled down to 100 K. The ultimate beam handling capability of such target is determined by the properties of the window. Reliable performance of this gas target system was achieved at 1 bar of deuterium gas, when exposed to a 45 μA beam of 5 MeV deuterons, for periods in excess of 6 h. Cooling of the target gas resulted in increased fast neutron output and improved neutron to gamma-ray ratio. The second part of this paper discusses the design of a high pressure, windowless gas target for use with pulsed, low duty cycle accelerators. A rotating seal concept was applied to reduce the gas load in a differentially pumped system. This allows operation at 1.23 bar of deuterium gas pressure in the gas cell region. Such a gas target system is free from the limitations of the windowed target but special attention has to be paid to the heat dissipation capability of the beam dump, due to the use of a thin target. The rotating seal concept is particularly suitable for use with accelerators such as radio-frequency quadrupole (RFQ) linacs that operate with a very high peak current at low duty cycle. The performance of both target systems was comprehensively characterized using the time-of-flight (TOF) technique. This demonstrated that very good quality mono-energetic fast neutron beams were produced with the slow neutron and gamma-ray component below 10% of the total target output

Polarized few-nucleon targets: new developments

International Nuclear Information System (INIS)

Haeusser, O.

1992-09-01

We discuss recent improvements in producing polarized few-nucleon targets for nuclear and particle physics experiments. The emphasis is on progress with polarized gas targets intended for experiments at electron and proton storage rings. (author) 54 refs., 1 tab

Polarized few-nucleon targets: new developments

Energy Technology Data Exchange (ETDEWEB)

Haeusser, O

1992-09-01

We discuss recent improvements in producing polarized few-nucleon targets for nuclear and particle physics experiments. The emphasis is on progress with polarized gas targets intended for experiments at electron and proton storage rings. (author) 54 refs., 1 tab.

Baryon spectroscopy with polarization observables from CLAS

Energy Technology Data Exchange (ETDEWEB)

Strauch, Steffen [Univ. of South Carolina, Columbia, SC (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2016-11-01

The spectrum of nucleon excitations is dominated by broad and overlapping resonances. Polarization observables in photoproduction reactions are key in the study of these excitations. They give indispensable constraints to partial-wave analyses and help clarify the spectrum. A series of polarized photoproduction experiments have been performed at the Thomas Jefferson National Accelerator Facility with the CEBAF Large Acceptance Spectrometer (CLAS). These measurements include data with linearly and circularly polarized tagged-photon beams, longitudinally and transversely polarized proton and deuterium targets, and recoil polarizations through the observation of the weak decay of hyperons. An overview of these studies and recent results will be given.

COMPASS polarized target for Drell-Yan

CERN Document Server

Pešek, M

2014-01-01

In the COMPASS Drell–Yan experiment the pion beam with momen tum of 190 GeV/ c and in- tensity up to 10 8 pions/s will interact with transversely polarized proton t arget producing muon pair via Drell–Yan process. The solid-state NH 3 will be polarized by dynamic nuclear polar- ization. Maximum polarization reached during data taking i s expected to be up to 90%. The non-interacting beam and other particles produced inside t he target will be stopped in the hadron absorber after the target. Two target cells, sepparated by a 20 cm gap in between, each 55 cm long and 4 cm in diameter give the target material volume about 691 cm 3 . The target platform needs to be moved by 2.3 m in upstream dire ction from the position used in previous experiments in order to accomodate the absorber. D uring the beam time higher radiation is expected in the area of the control room. Thus a new target r emote control system is needed. The target magnet is undergoing a substantial upgrade. Drell–Yan data taking is expected t...

The polarized double cell target of the SMC

CERN Document Server

Adams, D; Adeva, B; Arik, E; Arvidson, A; Badelek, B; Ballintijn, M K; Bardin, G; Baum, G; Berglund, P; Betev, L; Bird, I G; Birsa, R; Björkholm, P; Bonner, B E; De Botton, N R; Boutemeur, M; Bradamante, Franco; Bravar, A; Bressan, A; Bültmann, S; Burtin, E; Cavata, C; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Derro, B R; Deshpande, A A; Dhawan, S K; Dulya, C M; Dyring, A; Eichblatt, S; Faivre, Jean-Claude; Fasching, D; Feinstein, F; Fernández, C; Forthmann, S; Frois, Bernard; Gallas, A; Garzón, J A; Gaussiran, T; Gilly, H; Giorgi, M A; von Goeler, E; Görtz, S; Gracia, G; De Groot, N; Grosse-Perdekamp, M; Gülmez, E; Haft, K; Von Harrach, D; Hasegawa, T; Hautle, P; Hayashi, N; Heusch, C A; Horikawa, N; Hughes, V W; Igo, G; Ishimoto, S; Iwata, T; Kabuss, E M; Kageya, T; Karev, A G; Kessler, H J; Ketel, T; Kiryluk, J; Kishi, A; Kiselev, Yu F; Klostermann, L; Krämer, Dietrich; Krivokhizhin, V G; Kröger, W; Kurek, K; Kyynäräinen, J; Lamanna, M; Landgraf, U; Layda, T; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Lindqvist, T; Litmaath, M; Loewe, M; Magnon, A; Mallot, G K; Marie, F; Martin, A; Martino, J; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Meyer, W T; Van Middelkoop, G; Miller, D; Miyachi, Y; Mori, K; Moromisato, J H; Nassalski, J P; Naumann, Lutz; Neganov, B S; Niinikoski, T O; Oberski, J; Ogawa, A; Ozben, C; Parks, D P; Pereira, H; Penzo, Aldo L; Perrot-Kunne, F; Peshekhonov, V D; Piegaia, R; Pinsky, L; Platchkov, S K; Pló, M; Pose, D; Postma, H; Pretz, J; Pussieux, T; Pyrlik, J; Rädel, G; Reyhancan, I; Reicherz, G; Rijllart, A; Roberts, J B; Rock, S E; Rodríguez, M; Rondio, Ewa; Rosado, A; Roscherr, B; Sabo, I; Saborido, J; Sandacz, A; Savin, I A; Schiavon, R P; Schiller, A; Schüler, K P; Segel, R E; Seitz, R; Semertzidis, Y K; Sever, F; Shanahan, P; Sichtermann, E P; Simeoni, F; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Szleper, M; Teichert, K M; Tessarotto, F; Thers, D; Tlaczala, W; Trentalange, S; Tripet, A; Ünel, G; Velasco, M; Vogt, J; Voss, Rüdiger; Weinstein, R; Whitten, C; Windmolders, R; Willumeit, R; Wislicki, W; Witzmann, A; Zanetti, A M; Zaremba, K; Zhao, J

1999-01-01

The polarized target of the Spin Muon Collaboration at CERN was used for deep inelastic muon scattering experiments during 1993 to 1996 with a polarized muon beam to investigate the spin structure of the nucleon. Most of the experiments were carried out with longitudinal target polarization and 190 GeV muons, and some were done with transverse polarization and 100 GeV muons. Protons as well as deuterons were polarized by dynamic nuclear polarization (DNP) in three kinds of solid materials $-$ butanol, ammonia, and deuterated butanol, with maximum degrees of polarization of 94, 91, and 60 \\%, respectively. Considerable attention was paid to the accuracies of the NMR polarization measurements and their analyses. The achieved accuracies were between 2.0 and 3.2 \\%. The SMC target system with two cells of opposite polarizations, each cell 65 cm long and 5 cm in diameter, constitutes the largest polarized target system ever built and facilitates accurate spin asymmetry measurements. The design considerations, the ...

Superconducting polarizing magnet for a movable polarized target

International Nuclear Information System (INIS)

Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

1998-01-01

The superconducting polarizing magnet was constructed for the JINR (Dubna) movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T in the centre with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet contains a main solenoidal winding 558 mm long and 206/144 mm in diameters, and compensating and correcting winding placed at its ends. The windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat. The diameter of the 'warm' aperture of the magnet cryostat is 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements, using a NMR-magnetometer are given. A similar magnet constructed at DAPNIA, CEA/Saclay (France), represented a model for the present development. The MPT array is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the synchrophasotron of the Laboratory of High Energies (LHE), JINR (Dubna)

Requirements on internal targets for the Aladdin storage ring

International Nuclear Information System (INIS)

Holt, R.J.

1984-01-01

The feasibility of performing electron scattering experiments with polarized targets in electron storage rings is explored by considering an electron-deuteron scattering experiment at the Aladdin storage ring. It is noted that this new method is compatible with recent proposals for linac-stretcher-ring accelerator designs. A new method for producing a polarized hydrogen or deuterium target is proposed and some preliminary results are described. 21 references, 6 figures, 1 table

Θ"+ search at HERMES with deuterium and hydrogen targets

International Nuclear Information System (INIS)

Wang Siguang; Schnell, Gunar

2016-01-01

The previous search at HERMES for narrow baryon states excited in quasi-real photo-production, decaying through the channel Θ"+ → pK_S"0 → pπ"+ π"-, has been extended. Improved decay-particle reconstruction, more advanced particle identification, and increased event samples are employed. The structure that was observed earlier at an invariant mass of 1528 MeV shifts to 1522 MeV in the new analysis of data with a deuterium target, with a drop of statistical significance to about 2σ. The number of events above background is 68_-_3_1"+"9"8(stat)±13(sys). No such structure is observed in the hydrogen data set. (author)

Dynamically polarized hydrogen target as a broadband, wavelength-independent thermal neutron spin polarizer

International Nuclear Information System (INIS)

Zhao Jinkui; Garamus, Vasil M.; Mueller, Wilhelm; Willumeit, Regine

2005-01-01

A hydrogen-rich sample with dynamically polarized hydrogen nuclei was tested as a wavelength-independent neutron transmission spin polarizer. The experiment used a modified setup of the dynamic nuclear polarization target station at the GKSS research center. The standard solvent sample at the GKSS DNP station was used. It is 2.8mm thick and consists of 43.4wt% water, 54.6wt% glycerol, and 2wt% of EHBA-Cr(v) complex. The wavelength of the incident neutrons for the transmission experiment was λ=8.1A with Δλ/λ=10%. The polarization of neutron beam after the target sample was analyzed with a supermirror analyzer. A neutron polarization of -52% was achieved at the hydrogen polarization of -69%. Further experiments will test the feasibility of other hydrogen-rich materials, such as methane, as the polarizer. A theoretical calculation shows that a polarized methane target would allow over 95% neutron polarizations with more than 30% transmission

Measurement of the Asymmetry of Photoproduction of π- Mesons on Linearly Polarized Deuterons by Linearly Polarized Photons

Science.gov (United States)

Gauzshtein, V. V.; Zevakov, S. A.; Levchuk, M. I.; Loginov, A. Yu.; Nikolenko, D. M.; Rachek, I. A.; Sadykov, R. Sh.; Toporkov, D. K.; Shestakov, Yu. V.

2018-05-01

The first results of a double polarization experiment to extract the asymmetry of the reaction of photoproduction of a π- meson by a linearly polarized photon on a tensor-polarized deuteron in the energy range of the virtual photon (300-700 MeV) are presented. The measurements were performed on an internal tensor-polarized deuterium target in the VEPP-3 electron-positron storage ring for the electron beam energy equal to 2 GeV. The experiment employed the method of recording two protons and the scattered electron in coincidence. The obtained measurement results are compared with the theoretical predictions obtained in the momentum approximation with allowance for πN and NN rescattering in the final state.

Polarized target as analyzer of polarization of particle beam with spin Ssub(B)=1/2

International Nuclear Information System (INIS)

Golovin, V.M.; Golubeva, M.B.; Gornushkin, Yu.A.

1982-01-01

A possibility of using a polarized target as a target analyzer of beam particle polarization (Ssub(T)=1/2 Psub(T) vector) so that all the components of beam polarization Ssub(B)=1/2 anti Psub(B) should be determined in one experiment, is revealed. A proton polarization target is considered as a polarization target-analyzer. Asub(SK) and Asub(kk) asymmetry tensors are considered for elastic pp and pn scatterings by amplitudes of NN scattering which attain the values of 0.3-0.9 at 95-400 MeV. Asub(kk)(pp) and Asub(sk)(pp) are experimentally measured in the 445-576 MeV range. It is found that their highest absolute values are equal to 0.4-0.5 and 0.2-0.3 respectively. Elastic proton scattering on polarized electrons may be another variant of using polarized target for measuring proton beam polarization. Asub(sk) and Asub(kk) components of asymmetry tensor of elastic pe scattering are graphically presented. A possibility of using a polarized charge with spin I=1/2 as a target-analyzer of particle beam polarization is marked

Laser ``M'egajoule'' cryogenic target program: from target fabrication to conformation of the deuterium-tritium ice layer

Science.gov (United States)

Collier, Rémy; Durut, Frédéric; Reneaume, Benoît; Chicane, Cédric; Théobald, Marc; Breton, Olivier; Martin, Michel; Fleury, Emmanuel; Vincent-Viry, Olivier; Bachelet, Franck; Jeannot, Laurent; Geoffray, Isabelle; Botrel, Ronan; Dauteuil, Christophe; Hermerel, Cyril; Choux, Alexandre; Bednarczyk, Sophie; Legaie, Olivier

2008-11-01

For the French inertial confinement fusion (ICF) experiments, cryogenic target assemblies (CTAs) for the LMJ program are manufactured and filled at CEA Valduc (Dijon) in the cryogenic targets filling station (IRCC). They will be moved at about 20 K into a transport cryostat for cryogenic targets and will be driven from CEA/Valduc to CEA/CESTA (Bordeaux). Cryogenic targets will then be transferred by several cryogenic grippers on the cryogenic target positioner before shots. The CTA has to meet severe specifications and involves a lot of challenging tasks for its manufacture. To fill CTAs by permeation with deuterium-tritium (DT), the IRCC need to meet strict thermal, mechanical and dimensional specifications. To obtain a good combustion yield, a very homogenous DT ice layer and very smooth roughness at 1.5 K below the DT triple point are also required. This paper deals with the up to date main issues in the different fields of the LMJ cryogenic target program.

Polarized proton target-IV. Operations manual

International Nuclear Information System (INIS)

Hill, D.; Fletcher, O.; Moretti, A.; Onesto, F.

1976-01-01

Standard operating procedures are presented for the vacuum, cryogenic, and electronic systems of a polarized proton target. The systems are comprised of (1) a target cryostat; (2) a 4 He pumping system; (3) a 3 He pumping system; (4) a microwave system; (5) a magnet and power supply; (6) a computerized polarization monitor; and (7) miscellaneous auxiliary equipment

Ex-vacuo nuclear reaction analysis of deuterium

International Nuclear Information System (INIS)

Lee, S.R.; Doyle, B.L.

1989-01-01

A novel technique for performing in-air d( 3 He, p) nuclear reaction analysis of deuterium using external 3 He ion beams ranging in energy from 0.3-2.0 MeV is presented. Variable on-target beam energies for the depth profiling of deuterium are obtained by varying the transmission distance of the external 3 He beam in air. The ex-vacuo nuclear reaction analysis (XNRA) apparatus is described, and unique aspects and limitations of in-air depth profiling of deuterium using the d( 3 He, p) reaction are discussed. Example analyses where XNRA has been used for the multidimensional measurement of deuterium in fusion reactor components are presented in order to illustrate the advantages of XNRA for deuterium. These advantages include nondestructive analysis of large targets, efficient depth profiling via variable air gap energy tuning, and rapid analysis of numerous samples in the absence of vacuum cycling. (orig.)

Optically pumped electron spin polarized targets for use in the production of polarized ion beams

International Nuclear Information System (INIS)

Anderson, L.W.

1979-01-01

The production of relatively dense electron spin polarized alkali metal vapor targets by optical pumping with intense cw dye lasers is discussed. The target density and electron spin polarization depend on the dye laser intensity and bandwidth, the magnetic field at the target, and the electron spin depolarization time. For example in a magnetic field of 1.5 x 10 3 G, and using 1 W dye laser with a bandwidth of 10 10 Hz one can construct an electron spin polarized Na vapor target with a target thickness of 1.6 x 10 13 atoms/cm 2 and an average electron spin polarization of about 90% even though the Na atoms are completely depolarized at every wall collision. Possible uses of the electron spin polarized targets for the production of intense beams of polarized H - or 3 He - ions are discussed. (orig.)

Cryogenic polarized target facility: status

International Nuclear Information System (INIS)

Gould, C.; Nash, H.K.; Roberson, N.; Schneider, M.; Seagondollar, W.; Soderstrum, J.

1985-01-01

The TUNL cryogenically polarized target facility consists of a 3 He- 4 He dilution refrigerator and a superconducting magnet, together capable of maintaining samples at between 10 and 20 mK in magnetic fields up to 7 Tesla. At these temperatures and magnetic fields brute-force nuclear orientation occurs. Polarizations from 20 to 60% are attainable in about twenty nonzero spin nuclei. Most are metals, ranging in mass from 6 Li to 209 Bi, but the nuclei 1 H and 3 He are also polarizable via this method. The main effort is directed towards a better determination of the effective spin-spin force in nuclei. These experiments are briefly described and the beam stabilization system, cryostat and polarized 3 He targets are discussed

System of measurement of proton polarization in a polarized target

Energy Technology Data Exchange (ETDEWEB)

Karnaukov, I.M.; Chechetenko, V.F.; Lukhanin, A.A.; Telegin, Y.N.; Trotsenko, V.I.

1985-05-01

This paper describes a nuclear magnetic resonance spectrometer with high sensitivity. The signal of NMR absorption is recorded by a Q-meter with a series circuit and a circuit for compensation of the resonance characteristic of the measuring circuit. In order to ensure uniform sensitivity of the system to the state of polarization throughout the volume of the target and to enhance the S/N ration the measuring coil is made of a flat conductor. The polarization-measuring system works on-line with an M-6000 computer. The total error of measurement of the polarization of free protons in a target with allowance for the error due to local depolarization of free protons in a target with allowance for the error due to local depolarization of the working substance under irradiation with an intense photon beam is less than or equal to 6%.

Report of the workshop on polarized target materials

International Nuclear Information System (INIS)

Court, G.R.; Crabb, D.G.; Fernow, R.C.; Fitzgerald, D.H.; Gray, S.W.; Hill, D.A.; Jarmer, J.J.; Krisch, A.D.; Krumpolic, M.; Niinikoski, T.O.

1978-01-01

The workshop concentrated on an examination of: radiation damage in polarized target materials, a survey of clean target materials, and dynamic polarization results with the new stable Cr(V) complexes. In addition to the normal polarized target experts with backgrounds in high energy physics, low temperature physics and solid state physics, scientists with strong backgrounds in various areas of chemistry and radiation damage physics were included, as these areas were quite crucial to the workshop goals. However, it is clear that much closer collaboration with experts in these areas will be necessary to find polarized target materials that allow more precise experiments on high P 2 perpendicular processes and inclusive processes

Relativistic description of the Fermi motion effects on deuterium targets

International Nuclear Information System (INIS)

Kusno, D.

1979-12-01

A comprehensive analysis of the inconsistencies of the conventional, non-relativistic approach, which has been used so far in the extraction of neutron data from deuterium targets, is given. A new approach dealing with the smearing effects, due to the nucleon's Fermi motion inside the deuteron, is developed as an alternative to the conventional one. This new approach is a spin-less, relativistic, simple and consistent approach. A new covariant model of the elastic electromagnetic form factors of the deuteron in the impulse approximation is also presented. The treatment includes spin and allows for a possibility of determining completely the two elastic structure functions

Influence of tungsten microstructure and ion flux on deuterium plasma-induced surface modifications and deuterium retention

NARCIS (Netherlands)

Buzi, L.; De Temmerman, G.; Unterberg, B.; M. Reinhart,; Dittmar, T.; Matveev, D.; Linsmeier, C.; Breuer, U.; Kreter, A.; Van Oost, G.

2015-01-01

The influence of surface temperature, particle flux density and material microstructure on the surface morphology and deuterium retention was studied by exposing tungsten targets (20 μm and 40 μm grain size) to deuterium plasma at the same particle fluence (1026 m−2) and

New investigations of polarized solid HD targets

International Nuclear Information System (INIS)

Honig, A.; Whisnant, C.S.

1995-01-01

Polarized solid HD targets in a frozen-spin mode, with superior nuclear physics characteristics and simple operational configurations, have previously been restricted in their deployment due to a disproportionate target production time with respect to utilization time. Recent investigations have yielded frozen-spin polarization lifetimes, at a convenient target temperature of 1.5 K, of nearly a year for both H and D at high holding fields, and of more than a week at sub-Tesla holding fields. These results, taken together with the advent of new interesting spin-physics using relatively weakly ionizing beams, such as polarized photon beams, remove the above impediment and open up the use of polarized solid HD to long duration nuclear spin-physics experiments. Large, multiple targets can be produced, retrieved from the polarization-production apparatus with a cold-transport (4 K) device, stored for very long times in inexpensive (1.5 K, 7 T) cryostats, and introduced 'off-the-shelf' into in-beam cryostats via the portable cold-transport apparatus. Various modes for achieving polarized H and/or D, as well as already achieved and expected polarization values, are reported. Experimental results are given on Kapitza resistance between the solid HD and the cooling wires necessary to obtain low temperatures during the heat-evolving polarization process. 15 mK is achievable using gold-plated aluminum wires, which constitute 15% extraneous nucleons over the number of polarizable H or D nucleons. Application to more highly ionizing beams is also given consideration. ((orig.))

Broad-aperture polarized proton target with arbitrary orientation of polarization vector

International Nuclear Information System (INIS)

Belyaev, A.A.; Get'man, V.A.; Derkach, A.Ya.; Karnaukhov, I.M.; Lukhanin, A.A.; Razumnyj, A.A.; Sorokin, P.V.; Sporov, E.A.; Telegin, Yu.N.; Trotsenko, V.I.

1985-01-01

Polarized proton target with the Helmholtz broad-aperture superconducting magnetic system is described. Axial aperture α=95 deg, inter-coil access angle β=23 deg. The structure of the target allows various versions of the installation what make sure an arbitrary orientation of polarization vector. The 0.1 W cold output 3 He evaporation cryostat was used to obtain the work temperature 0.5 K allowing quick transformation to a 3 He- 4 He dilution refrigerator. Results of the study are given on the dynamical proton polarization in 1,2-propylenglycol with various stable Cr 5 complexes

Proceedings of the workshop on polarized targets in storage rings

International Nuclear Information System (INIS)

Holt, R.J.

1984-08-01

Polarization phenomena have played an increasingly important part in the study of nuclei and nucleons in recent years. Polarization studies have been hampered by the relatively few and rather fragile polarized targets which are presently available. The concept of polarized gas targets in storage rings opens a much wider range of possibilities than is available in the external target geometry. This novel method will represent a considerable advance in nuclear physics and will continue to receive much attention in plans for future facilities. An internal, polarized-target station is being planned for the cooler ring at the Indiana University Cyclotron Facility. Internal targets are compatible with recent designs of electron accelerators proposed by the Massachusetts Institute of Technology and the Southeastern Universities Research Association. The key to nuclear-science programs based on internal targets pivots on recent developments in polarized atomic beam methods, which include the more recent laser-driven polarized targets. The workshop drew together a unique group of physicists in the fields of high-energy, nuclear and atomic physics. The meeting was organized in a manner that stimulated discussion among the 58 participants and focused on developments in polarized target technology and the underlying atomic physics. An impressive array of future possibilities for polarized targets as well as current developments in polarized target technology were discussed at the workshop. Abstracts of individual items from the workshop were prepared separately for the data base

Polarized proton and deuteron solid HD targets

International Nuclear Information System (INIS)

Honig, A.

1977-01-01

A decade has now elapsed since HD was proposed as a polarized proton and deuteron target with exceptionally desirable properties. These include a very high free proton proportion, independently polarizable proton and deuteron systems, and a ''frozen-spin'' mode of operation which allows separation of the functions of production and utilization of the highly polarized target. A discussion is given of what can be expected of the polarized HD system right now, without further research. The basic features of solid HD pertinent to its use as a ''frozen-spin'' target are outlined, then a summary is given of the particular experimental results which support the contention that the target will perform successfully, and finally, some feasible operating modes and the expected performances from them are presented

Numerical studies of deuterium-tritium ignition in impact-fusion targets

International Nuclear Information System (INIS)

Zubrin, R.M.; Ribe, F.L.

1989-01-01

A numerical one-dimensional solution of the Euler equations for an imploding spherical tungsten shell with internal deuterium-tritium gas is applied to study impact-fusion dynamics with parameters of fusion reactor relevance. Thermal conduction and radiative energy loss by the plasma are taken into account, as is heating by fusion generated alpha particles. A variety of target sizes and impact velocities are examined, and scaling laws for fusion yields are deduced which define possible parameters for conceptual commercial impact-fusion power reactors. It is found that shell energies and velocities of about 30 MJ and 110 km/s would be satisfactory. A commercial impact-fusion reactor based on such parameters is discussed

A horizontal dilution refrigerator for polarized target

International Nuclear Information System (INIS)

Isagawa, S.; Ishimoto, S.; Masaike, A.; Morimoto, K.

1978-01-01

A horizontal dilution refrigerator was constructed with a view to the spin frozen target and the deuteron polarized target. High cooling power at high temperature such as 3.7 mW at 400 mK serves for overcoming a heat load of microwave to polarize the nuclear spins in the target material. The cooling power at 50 mK was 50 μW, which is sufficient to hold the high nuclear polarization for long time. The lowest temperature reached was 26 mK. The refrigerator has rather simple heat exchangers, a long stainless steel double tube heat exchanger and two coaxial type heat exchangers with sintered copper. The mixing chamber is made of polytetrafluoroethylene (TFE) and demountable so that the target material can be easily put into it. (Auth.)

Nuclear spin polarized H and D by means of spin-exchange optical pumping

Science.gov (United States)

Stenger, Jörn; Grosshauser, Carsten; Kilian, Wolfgang; Nagengast, Wolfgang; Ranzenberger, Bernd; Rith, Klaus; Schmidt, Frank

1998-01-01

Optically pumped spin-exchange sources for polarized hydrogen and deuterium atoms have been demonstrated to yield high atomic flow and high electron spin polarization. For maximum nuclear polarization the source has to be operated in spin temperature equilibrium, which has already been demonstrated for hydrogen. In spin temperature equilibrium the nuclear spin polarization PI equals the electron spin polarization PS for hydrogen and is even larger than PS for deuterium. We discuss the general properties of spin temperature equilibrium for a sample of deuterium atoms. One result are the equations PI=4PS/(3+PS2) and Pzz=PSṡPI, where Pzz is the nuclear tensor polarization. Furthermore we demonstrate that the deuterium atoms from our source are in spin temperature equilibrium within the experimental accuracy.

Polarized proton target with horizontal spin orientation

International Nuclear Information System (INIS)

Bunyatova, Eh.I.; Kiselev, Yu.F.; Kozlenko, N.G.

1988-01-01

Proton target, the polarization vector of which may be arbitrary oriented in horizontal plane relatively to the beam, is developed and tested. 70% value of polarization is obtained. 0.6 K temperature is acquired through 3 He pumping out continuous cycle. 1.2-propylene glycol - Cr(V) was used as working medium. Magnetic system is made in the form of Helmholtz sperconducting coils with working curren close to critical one. Target polarization is measured by NMR technique using original system of proton signal processing

Compression of a spherically symmetric deuterium-tritium plasma liner onto a magnetized deuterium-tritium target

International Nuclear Information System (INIS)

Santarius, J. F.

2012-01-01

Converging plasma jets may be able to reach the regime of high energy density plasmas (HEDP). The successful application of plasma jets to magneto-inertial fusion (MIF) would heat the plasma by fusion products and should increase the plasma energy density. This paper reports the results of using the University of Wisconsin’s 1-D Lagrangian, radiation-hydrodynamics, fusion code BUCKY to investigate two MIF converging plasma jet test cases originally analyzed by Samulyak et al.[Physics of Plasmas 17, 092702 (2010)]. In these cases, 15 cm or 5 cm radially thick deuterium-tritium (DT) plasma jets merge at 60 cm from the origin and converge radially onto a DT target magnetized to 2 T and of radius 5 cm. The BUCKY calculations reported here model these cases, starting from the time of initial contact of the jets and target. Compared to the one-temperature Samulyak et al. calculations, the one-temperature BUCKY results show similar behavior, except that the plasma radius remains about twice as long near maximum compression. One-temperature and two-temperature BUCKY results differ, reflecting the sensitivity of the calculations to timing and plasma parameter details, with the two-temperature case giving a more sustained compression.

High pressure deuterium-tritium gas target vessels for muon-catalyzed fusion experiments

International Nuclear Information System (INIS)

Caffrey, A.J.; Spaletta, H.W.; Ware, A.G.; Zabriskie, J.M.; Hardwick, D.A.; Maltrud, H.R.; Paciotti, M.A.

1989-01-01

In experimental studies of muon-catalyzed fusion, the density of the hydrogen gas mixture is an important parameter. Catalysis of up to 150 fusions per muon has been observed in deuterium-tritium gas mixtures at liquid hydrogen density; at room temperature, such densities require a target gas pressure of the order of 1000 atmospheres (100 MPa, 15,000 psi). We report here the design considerations for hydrogen gas target vessels for muon-catalyzed fusion experiments that operate at 1000 and 10,000 atmospheres. The 1000 atmosphere high pressure target vessels are fabricated of Type A-286 stainless steel and lined with oxygen-free, high-conductivity (OFHC) copper to provide a barrier to hydrogen permeation of the stainless steel. The 10,000 atmosphere ultrahigh pressure target vessels are made from 18Ni (200 grade) maraging steel and are lined with OFHC copper, again to prevent hydrogen permeation of the steel. In addition to target design features, operating requirements, fabrication procedures, and secondary containment are discussed. 13 refs., 3 figs., 1 tab

Studies of spin relaxation and recombination at the HERMES hydrogen/deuterium gas target

International Nuclear Information System (INIS)

Baumgarten, C.

2000-09-01

The HERMES (HERA measurement of spin) experiment is located in the eastern straight section of the HERA storage ring at DESY in Hamburg. It is designed to study the spin structure of the nucleons by deep inelastic scattering of polarized positrons resp. electrons provided by the HERA storage ring at 27.5 GeV impingingon the nucleons of internal polarized gas targets. The setup of the HERMES experiment is shown. First results are the measurement of the spin structure functions g 1 n with the polarized 3 He target (1995) and of g 1 p with polarized atomic hydrogen target, which was operated in 1996 and 1997. Beneath the inclusive physics, the possibility to detect and identify hadronic scattering products allows the measurement of semi-inclusive processes with the central item of the HERMES physics program. (orig.)

Long-Lifetime Low-Scatter Neutron Polarization Target

International Nuclear Information System (INIS)

Richardson, Jonathan M.

2004-01-01

Polarized neutrons scattering is an important technology for characterizing magnetic and other materials. Polarized helium three (P-3He) is a novel technology for creating polarized beams and, perhaps more importantly, for the analysis of polarization in highly divergent scattered beams. Analysis of scattered beams requires specialized targets with complex geometries to ensure accurate results. Special materials and handling procedures are required to give the targets a long useful lifetime. In most cases, the targets must be shielded from stray magnetic fields from nearby equipment. SRL has developed and demonstrated hybrid targets made from glass and aluminum. We have also developed and calibrated a low-field NMR system for measuring polarization lifetimes. We have demonstrated that our low-field system is able to measure NMR signals in the presence of conducting (metallic) cell elements. We have also demonstrated a non-magnetic valve that can be used to seal the cells. We feel that these accomplishments in Phase I are sufficient to ensure a successful Phase II program. The commercial market for this technology is solid. There are over nine neutron scattering centers in the US and Canada and over 22 abroad. Currently, the US plans to build a new $1.4B scattering facility called the Spallation Neutron Source (SNS). The technology developed in this project will allow SRL to supply targets to both existing and future facilities. SRL is also involved with the application of P-3He to medical imaging

Polarized deuteron elastic scattering from a polarized proton target

International Nuclear Information System (INIS)

Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R.; Zankel, H.

1983-01-01

Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76 0 ,85 0 ,98 0 ,115 0 ,132 0 ). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results. (orig.)

Polarized deuteron elastic scattering from a polarized proton target

Energy Technology Data Exchange (ETDEWEB)

Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Physikalisches Inst.); Zankel, H. (Graz Univ. (Austria). Inst. fuer Theoretische Physik)

1983-01-13

Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76/sup 0/,85/sup 0/,98/sup 0/,115/sup 0/,132/sup 0/). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results.

H- ion current from a polarized vapor target

International Nuclear Information System (INIS)

Cornelius, W.D.

1984-01-01

A method of determining the polarization transferred to hydrogen atoms in charge-exchange reactions is outlined. The method also provides a means of determining target polarizations once the polarization transfer function is known

Nonlinear Magnetic Phenomena in Highly Polarized Target Materials

CERN Document Server

Kiselev, Yu F

2007-01-01

The report introduces and surveys nonlinear magnetic phenomena which have been observed at high nuclear polarizations in polarized targets of the SMC and of the COMPASS collaborations at CERN. Some of these phenomena, namely the frequency modulation eect and the distortion of the NMR line shape, promote the development of the polarized target technique. Others, as the spin-spin cross-relaxation between spin subsystems can be used for the development of quantum statistical physics. New findings bear on an electromagnetic noise and the spectrally resolved radiation from LiD with negatively polarized nuclei detected by low temperature bolometers. These nonlinear phenomena need to be taken into account for achieving the ultimate polarizations.

The SLAC high-density gaseous polarized 3He target

International Nuclear Information System (INIS)

Johnson, J.R.; Chupp, T.E.; Smith, T.B.; Cates, G.D.; Driehuys, B.; Middleton, H.; Newbury, N.R.; Hughes, E.W.; Meyer, W.

1995-01-01

A large-scale high-pressure gaseous 3 He polarized target has been developed for use with a high-intensity polarized electron beam at the Stanford Linear Accelerator Center. This target was used successfully in an experiment to study the spin structure of the neutron. The target provided an areal density of about 7x10 21 nuclei/cm 2 and operated at 3 He polarizations between about 30% and 40% for the six-week duration of the experiment. ((orig.))

Polarized Electron Beams for Nuclear Physics at the MIT Bates Accelerator Center

CERN Document Server

Farkhondeh, Manouchehr; Franklin, Wilbur; Ihloff, Ernie; McAllister, Brian; Milner, Richard; North, William; Tschalär, C; Tsentalovich, Evgeni; Wang, Defa; Wang, Dong; Wang, Fuhua; Zolfaghari, Abbasali; Zwart, Townsend; van der Laan, Jan

2005-01-01

The MIT Bates Accelerator Center is delivering highly polarized electron beams to its South Hall Ring for use in Nuclear Physics Experiments. Circulating electron currents in excess of 200 mA with polarization of 70% are scattered from a highly polarized, but very thin atomic beam source deuterium target. At the electron source a compact diode laser creates photoemission of quasi-CW mA pulses of polarized electrons at low duty factors from a strained GaAs photocathode. Refurbished RF transmitters provide power to the 2856 MHz linac, accelerating the beam to 850 MeV in two passes before injection into the South Hall Ring. In the ring a Siberian snake serves to maintain a high degree of longitudinal polarization at the BLAST scattering target. A Compton laser back-scattering polarimeter measures the electron beam polarization with a statistical acuracy of 6% every 15 minutes.

Laser-driven nuclear-polarized hydrogen internal gas target

International Nuclear Information System (INIS)

Seely, J.; Crawford, C.; Clasie, B.; Xu, W.; Dutta, D.; Gao, H.

2006-01-01

We report the performance of a laser-driven polarized internal hydrogen gas target (LDT) in a configuration similar to that used in scattering experiments. This target used the technique of spin-exchange optical pumping to produce nuclear spin polarized hydrogen gas that was fed into a cylindrical storage (target) cell. We present in this paper the performance of the target, methods that were tried to improve the figure-of-merit (FOM) of the target, and a Monte Carlo simulation of spin-exchange optical pumping. The dimensions of the apparatus were optimized using the simulation and the experimental results were in good agreement with the results from the simulation. The best experimental result achieved was at a hydrogen flow rate of 1.1x10 18 atoms/s, where the sample beam exiting the storage cell had 58.2% degree of dissociation and 50.5% polarization. Based on this measurement, the atomic fraction in the storage cell was 49.6% and the density averaged nuclear polarization was 25.0%. This represents the highest FOM for hydrogen from an LDT and is higher than the best FOM reported by atomic beam sources that used storage cells

Electric field measurements in a hollow cathode discharge by two-photon polarization spectroscopy of atomic deuterium

International Nuclear Information System (INIS)

Rosa, M I de la; Perez, C; Gruetzmacher, K; Gonzalo, A B; Steiger, A

2006-01-01

The local electric field strength (E-field) is an important parameter to be known in low pressure plasmas such as glow discharges, RF and microwave discharges, plasma boundaries in tokamaks etc. In this paper, we demonstrate, for the first time, the potential of two-photon polarization spectroscopy measuring the E-field in the cathode fall region of a hollow cathode discharge, via Doppler-free spectra of the Stark splitting of the 2S level of atomic deuterium. Electric field strength is determined in the range from 2 to 5 kV cm -1 . Compared with LIF, this method has several advantages: it is not affected by background radiation, it can be applied without limitation at elevated pressure and it allows simultaneous measurement of absolute local atomic ground state densities of hydrogen isotopes

A technique for measurement of vector and tensor polarization in solid spin one polarized targets

International Nuclear Information System (INIS)

Kielhorn, W.F.

1991-06-01

Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs

Construction and test of a polarized proton target

International Nuclear Information System (INIS)

Aures, R.

1983-12-01

This work describes experiments in which for the first time a proton target has been constructed which is polarized by the ''brute-force'' method. This method requires very low temperatures and high magnetic fields. The low temperatures (down to 10 mK) are obtained by a 3 He/ 4 He dilution refrigerator, the magnetic field (up to 9 T) is produced by a superconducting split pair magnet. The proton target has a volume of about 18 cm 3 and consists of pressed titaniumhydride powder, which has a titanium/-hydrogen ratio of 1:1,96. The hydrogen content is 1,3 mol. Titaniumhydride has the advantage of sufficient heat conductivity at low temperatures and a very high proton density. The heat conductivity of the sample is measured, with and without the presence of a magnetic field. Thermodynamical measurements and adiabatic demagnetisation experiments proved quantitatively the polarization of the protons. The polarization of the proton has been measured in a transmission experiment using polarized neutrons of 1.2 MeV. The result shows a good agreement of theoretical and actual polarization. From the results it can be concluded, that this sample can be used successfully as a polarized proton target for neutron scattering experiments to measure spin-correlations. (orig.) [de

Electro- and photonuclear physics with polarized beams and targets

International Nuclear Information System (INIS)

Holt, R.J.

1987-01-01

Two long-standing issues in photonuclear physics, the giant M1 resonance in Pb and deuteron photodisintegration, have been studied recently with polarized photons at Urbana and Frascati, respectively. The implications that this work has for settling these key issues will be discussed. In addition, the advantages of the internal polarized target method for electron scattering studies will be discussed and the technology of internal polarized target development will be reviewed. The first results from a spin-exchange, optically-pumped polarized H and D source will be presented

Superconducting shielding for a polarized target in PANDA

Energy Technology Data Exchange (ETDEWEB)

Mora Espi, Maria Carmen; Froehlich, Bertold; Dbeyssi, Alaa; Aguar Bartolome, Patricia; Gerz, Kathrin; Ahmed, Samer; Wang, Yadi; Lin, Dexu; Feldbauer, Florian [Helmholtz-Institut Mainz (Germany); Penuelas, Ana [Universitat de Valencia (Spain); Collaboration: PANDA-Collaboration

2016-07-01

The measurement of the phase between the electric and the magnetic form factors of the proton can be measured using a polarized interaction. A feasible possibility to allow this kind of reactions would be to develop a transversely polarized proton target to be used in the PANDA experiment. The first step to achieve the transverse target polarization is to study the feasibility of shielding the target region from the external 2 T longitudinal magnetic field generated by the PANDA solenoid. BSCOO-2212, a new high-temperature superconductor material, has been identified as a possible candidate to be used for shielding this external magnetic field. Tests at 4 K have taken place in the Helmholtz Institute Mainz with this material, and the first preliminary results are shown here.

Physics and technology of superthin internal targets in storage rings

International Nuclear Information System (INIS)

Popov, S.G.

1989-01-01

The new generation of accelerators for coincidence electronuclear investigations is discussed. The luminosity and beam parameters are calculated for an electron storage ring with an internal target operating in the superthin regime. The advantages and disadvantages in comparison with conventional operation using an external beam and target are described. The intermediate results for 2 GeV electron scattering on polarized internal deuterium target are given (joint Novosibirsk-Argonne experiment). 32 refs.; 5 figs

Recent results from the NN-interaction studies with polarized beams and targets at ANKE-COSY

Science.gov (United States)

Dymov, Sergey

2016-02-01

Adding to the nucleon-nucleon scattering database is one of the major priorities of the ANKE collaboration. Such data are necessary ingredients, not only for the understanding of nuclear forces, but also for the description of meson production and other nuclear reactions at intermediate energies. By measuring the cross section, deuteron analysing powers, and spin-correlation parameters in the dp → {pp}sn reaction, where {pp}s represents the 1S0 state, information has been obtained on small-angle neutron-proton spin-flip charge-exchange amplitudes. The measurements of pp elastic scattering by the COSY-EDDA have had a major impact on the partial wave analysis of this reaction above 1 GeV. However, these experiments only extended over the central region of c.m. angles, 300 < θcm < 1500, that has left major ambiguities in the phase shift analysis by the SAID group. In contrast, the small angle region is accessible at ANKE-COSY, that allowed measurement of the differential cross section and the analysing power at 50 < θcm < 300 in the 0.8 — 2.8 GeV energy range. The data on the pn elastic scattering are much more scarce than those of pp, especially in the region above 1.15 GeV. The study of the dp → {pp}s n reaction provides the information about the pn elastic scattering at large angles. The small angle scattering was studied with the polarized proton COSY beam and an unpolarised deuterium gas target. The detection the spectator proton in the ANKE vertex silicon detector allowed to use the deuterium target as an effective neutron one. The analysing powers of the process were obtained at six beam energies from 0.8 to 2.4 GeV.

A technique for measurement of vector and tensor polarization in solid spin one polarized targets

Energy Technology Data Exchange (ETDEWEB)

Kielhorn, W.F.

1991-06-01

Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs.

Polarized proton Target-III operators manual, revision A

International Nuclear Information System (INIS)

Hill, D.; Moretti, A.; Onesto, F.; Rynes, P.

1976-04-01

A revision is given of a manual containing standard operating procedures for the vacuum, cryogenic, and electronic systems of a polarized proton target. The discussion includes the target cryostat, the 3 He and 4 He pumping systems, remote monitors and controls, the microwave system, the magnet and power supply, the computerized polarization monitor, the 4 He liquifier and gas recovery system, and miscellaneous auxiliary equipment

Polarized proton and deuteron targets for the usage in intensive proton beams

International Nuclear Information System (INIS)

Get'man, V.A.; Derkach, A.Ya.; Karnaukhov, I.M.; Lukhanin, A.A.; Razumnyj, A.A.; Sorokin, P.V.; Sporo, E.A.; Telegin, Yu.N.

1982-01-01

Polarized proton and deuteron targets are developed and tested for conducting investigations in intense photon beams. A flowsheet of polarization targets which includes: working agent of the target, superconducting magnet, cryostat of 3 He evaporation with 3 He pumping and recirculation systems, SHF system of 4 mm range for polarization pumping, measuring system of target polarization protons is presented. Working agent of the targets includes frozen balls with 1.5 mm diameter. Ethylene-glucol and 1.2-propylene-glycol were used as a working substance for proton targets. Completely deuterated ethylene-glycol was used for the deuteron target. Vertical magnetic field with 2.7 T intensity is produced by a superconducting magnetic system. Polarization pumping is exercised at 75 GHz frequency. Q-meter of direct current is used for determination of polarization. Working temperature of the cryostat is approximately 0.5 K. The lock device permits to exercise replacement of the target working agent during 30 minutes

Prospects of polarized fixed target Drell-Yan experiments

International Nuclear Information System (INIS)

Liu, M X; Jiang, X; Crabb, D G; Chen, J P; Bai, M

2011-01-01

It has been proposed that the Siverse transverse single spin asymmetry in Drell-Yan production in transversely polarized p+p collisions would have an opposite sign compared to what has been observed in the polarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) experiments. Experimental confirmation or disproval of this prediction would provide a novel fundamental test of QCD and shed new light on our theoretical understanding of the transverse spin physics phenomena. We discuss the prospects and physics sensitivities of polarized fixed target Drell-Yan experiments that could utilize the existing proton and other hadron beams at Fermilab, and polarized proton beams at RHIC with a polarized solid proton and/or neutron target option. We show that if realized, the new experiments would provide critical measurements of not only the sign change (or not) of Sivers functions, but also the information of quark and antiquark's Sivers distributions over a wide kinematic range.

Modeling alignment enhancement for solid polarized targets

Energy Technology Data Exchange (ETDEWEB)

Keller, D. [University of Virginia, Charlottesville, VA (United States)

2017-07-15

A model of dynamic orientation using optimized radiofrequency (RF) irradiation produced perpendicular to the holding field is developed for the spin-1 system required for tensor-polarized fixed-target experiments. The derivation applies to RF produced close to the Larmor frequency of the nucleus and requires the electron spin-resonance linewidth to be much smaller than the nuclear magnetic resonance frequency. The rate equations are solved numerically to study a semi-saturated steady-state resulting from the two sources of irradiation: microwave from the DNP process and the additional RF used to manipulate the tensor polarization. The steady-state condition and continuous-wave NMR lineshape are found that optimize the spin-1 alignment in the polycrystalline materials used as solid polarized targets in charged-beam nuclear and particle physics experiments. (orig.)

Camouflaged target detection based on polarized spectral features

Science.gov (United States)

Tan, Jian; Zhang, Junping; Zou, Bin

2016-05-01

The polarized hyperspectral images (PHSI) include polarization, spectral, spatial and radiant features, which provide more information about objects and scenes than traditional intensity or spectrum ones. And polarization can suppress the background and highlight the object, leading to the high potential to improve camouflaged target detection. So polarized hyperspectral imaging technique has aroused extensive concern in the last few years. Nowadays, the detection methods are still not very mature, most of which are rooted in the detection of hyperspectral image. And before using these algorithms, Stokes vector is used to process the original four-dimensional polarized hyperspectral data firstly. However, when the data is large and complex, the amount of calculation and error will increase. In this paper, tensor is applied to reconstruct the original four-dimensional data into new three-dimensional data, then, the constraint energy minimization (CEM) is used to process the new data, which adds the polarization information to construct the polarized spectral filter operator and takes full advantages of spectral and polarized information. This way deals with the original data without extracting the Stokes vector, so as to reduce the computation and error greatly. The experimental results also show that the proposed method in this paper is more suitable for the target detection of the PHSI.

Effect of noble gas ion pre-irradiation on deuterium retention in tungsten

NARCIS (Netherlands)

Cheng, L.; Zhao, Z. H.; De Temmerman, G.; Yuan, Y.; Morgan, T. W.; Guo, L. P.; Wang, B.; Zhang, Y.; Wang, B. Y.; Zhang, P.; Cao, X. Z.; Lu, G. H.

2016-01-01

Impurity seeding of noble gases is an effective way of decreasing the heat loads onto the divertor targets in fusion devices. To investigate the effect of noble gases on deuterium retention, tungsten targets have been implanted by different noble gas ions and subsequently exposed to deuterium

A polarized atomic-beam target for COSY-Juelich

International Nuclear Information System (INIS)

Eversheim, P. D.; Altmeier, M.; Felden, O.; Glende, M.; Walker, M.; Hiemer, A.; Gebel, R.

1998-01-01

An atomic-beam target (ABT) for the EDDA experiment has been built in Bonn and was tested for the very first time at the cooler synchrotron COSY. The ABT differs from the polarized colliding-beams ion source for COSY in the DC-operation of the dissociator and the use of permanent 6-pole magnets. At present the beam optics of the ABT is set-up for maximum density in the interaction zone, but for target-cell operation it can be modified to give maximum intensity. The modular concept of this atomic ground-state target allows to provide all vector- (and tensor) polarizations for protons and deuterons, respectively. Up to now the polarization of the atomic-beam could be verified by the EDDA experiment to be > or approx. 80% with a density in the interaction zone of > or approx. 10 11 atoms/cm 2

Atmospheric influence on the deuterium excess signal in polar firn - implications for ice core interpretation

NARCIS (Netherlands)

Schlosser, Elisabeth; Oerter, H.; Masson-Delmotte, V.; Reijmer, C.H.

2008-01-01

The seasonal deuterium excess signal of fresh snow samples from Neumayer station, coastal Dronning Maud Land, Antarctica, was studied to investigate the relationship between deuterium excess and precipitation origin. An isotope model was combined with a trajectory model to determine the relative

Scattering of polarized electrons from polarized targets: Coincidence reactions and prescriptions for polarized half-off-shell single-nucleon cross sections

International Nuclear Information System (INIS)

Caballero, J.A.; Massachusetts Inst. of Tech., Cambridge, MA; Donnelly, T.W.; Massachusetts Inst. of Tech., Cambridge, MA; Poulis, G.I.; Massachusetts Inst. of Tech., Cambridge, MA

1993-01-01

Coincidence reactions of the type vector A( vector e, e'N)B involving the scattering of polarized electrons from polarized targets are discussed within the context of the plane-wave impulse approximation. Prescriptions are developed for polarized half-off single-nucleon cross sections; the different prescriptions are compared for typical quasi-free kinematics. Illustrative results are presented for coincidence polarized electron scattering from typical polarized nuclei. (orig.)

Selective deuterium ion acceleration using the Vulcan petawatt laser

Energy Technology Data Exchange (ETDEWEB)

Krygier, A. G. [Laboratoire pour l' Utilisation des Lasers Intenses, École Polytechnique, 91128 Palasiseau (France); Physics Department, The Ohio State University, Columbus, Ohio 43210 (United States); Morrison, J. T. [Propulsion Systems Directorate, Air Force Research Lab, Wright Patterson Air Force Base, Ohio 45433 (United States); Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.; Alejo, A.; Green, A.; Jung, D. [Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Clarke, R.; Notley, M. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Fuchs, J.; Vassura, L. [Laboratoire pour l' Utilisation des Lasers Intenses, École Polytechnique, 91128 Palasiseau (France); Kleinschmidt, A.; Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstrasse 9, D-64289 Darmstadt (Germany); Najmudin, Z.; Nakamura, H. [The John Adams Institute, Blackett Laboratory, Department of Physics, Imperial College, London SW7 2AZ (United Kingdom); Norreys, P. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Oliver, M. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Zepf, M. [Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Helmholtz Institute Jena, D-07743 Jena (Germany); Borghesi, M. [Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Institute of Physics of the ASCR, ELI-Beamlines Project, Na Slovance 2, 18221 Prague (Czech Republic); Freeman, R. R. [Physics Department, The Ohio State University, Columbus, Ohio 43210 (United States)

2015-05-15

We report on the successful demonstration of selective acceleration of deuterium ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison et al. [Phys. Plasmas 19, 030707 (2012)], an ion beam with >99% deuterium ions and peak energy 14 MeV/nucleon is produced with a 200 J, 700 fs, >10{sup 20}W/cm{sup 2} laser pulse by cryogenically freezing heavy water (D{sub 2}O) vapor onto the rear surface of the target prior to the shot. Within the range of our detectors (0°–8.5°), we find laser-to-deuterium-ion energy conversion efficiency of 4.3% above 0.7 MeV/nucleon while a conservative estimate of the total beam gives a conversion efficiency of 9.4%.

Selective deuterium ion acceleration using the Vulcan petawatt laser

International Nuclear Information System (INIS)

Krygier, A. G.; Morrison, J. T.; Kar, S.; Ahmed, H.; Alejo, A.; Green, A.; Jung, D.; Clarke, R.; Notley, M.; Fuchs, J.; Vassura, L.; Kleinschmidt, A.; Roth, M.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Zepf, M.; Borghesi, M.; Freeman, R. R.

2015-01-01

We report on the successful demonstration of selective acceleration of deuterium ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison et al. [Phys. Plasmas 19, 030707 (2012)], an ion beam with >99% deuterium ions and peak energy 14 MeV/nucleon is produced with a 200 J, 700 fs, >10 20 W/cm 2 laser pulse by cryogenically freezing heavy water (D 2 O) vapor onto the rear surface of the target prior to the shot. Within the range of our detectors (0°–8.5°), we find laser-to-deuterium-ion energy conversion efficiency of 4.3% above 0.7 MeV/nucleon while a conservative estimate of the total beam gives a conversion efficiency of 9.4%

Selective deuterium ion acceleration using the Vulcan petawatt laser

Science.gov (United States)

Krygier, A. G.; Morrison, J. T.; Kar, S.; Ahmed, H.; Alejo, A.; Clarke, R.; Fuchs, J.; Green, A.; Jung, D.; Kleinschmidt, A.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.; Freeman, R. R.

2015-05-01

We report on the successful demonstration of selective acceleration of deuterium ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison et al. [Phys. Plasmas 19, 030707 (2012)], an ion beam with >99% deuterium ions and peak energy 14 MeV/nucleon is produced with a 200 J, 700 fs, > 10 20 W / cm 2 laser pulse by cryogenically freezing heavy water (D2O) vapor onto the rear surface of the target prior to the shot. Within the range of our detectors (0°-8.5°), we find laser-to-deuterium-ion energy conversion efficiency of 4.3% above 0.7 MeV/nucleon while a conservative estimate of the total beam gives a conversion efficiency of 9.4%.

Local field in LiD polarized target material

CERN Document Server

Kisselev, Yu V; Baum, G; Berglund, P; Doshita, N; Gautheron, F; Görtz, S; Horikawa, N; Koivuniemi, J H; Kondo, K; Magnon, A; Meyer, Werner T; Reicherz, G

2004-01-01

We have experimentally studied the first and the second moments of D, **6Li and **7Li (I greater than 1/2) NMR lines in a granulated LiD- target material as a function of nuclear polarizations and the data has been compared with a theory elaborated by Abragam, Roinel and Bouffard for monocrystalline samples. The experiments were carried out in the large COMPASS twin-target at CERN. The static local magnetic field of the polarized nuclei was measured by frequency shift between the NMR-signals in the two oppositely polarized cells and lead to the first moment, whereas the investigation of the second moment was done through Gaussian approximation. The average field magnitude in granulated material was estimated 20% larger than the value given by the calculations for monocrystalline samples of cylindrical shape. The second moment shows a qualitative agreement with the theory but it is slightly larger at the negative than at the positive polarization. In a polarized mode, the moments depend on the saturated microw...

Exclusive ρ0 meson cross section ratios on deuterium and hydrogen targets

International Nuclear Information System (INIS)

Osborne, A.G.S.

2006-06-01

The HERMES experiment is a large forward angle spectrometer located at the HERA accelerator ring at DESY, Hamburg. This thesis presents the analysis of the kinematic dependencies of ρ 0 vector meson production on hydrogen and deuterium targets. The relative gluon and quark contribution to the ρ 0 production amplitude is expected to depend on the kinematical variable x Bj , and by measuring the ratio of ρ 0 electroproduction cross sections on deuterium and hydrogen from HERMES data this dependence is confirmed. This thesis describes the methods used to extract the cross section ratio from the HERMES data taken between the years 1996 and 2000 and compares the results with the theoretical predictions. Until 2005 the missing mass resolution of the HERMES spectrometer was only sufficient to allow exclusivity at the level of a data sample. The HERMES Recoil Detector, installed in early 2006, is an upgrade which will augment the HERMES spectrometer by establishing exclusivity at the event level and therefore improving the resolution to which various kinematical variables may be reconstructed. Additionally, the Recoil Detector will contribute to the overall background suppression capability of the HERMES spectrometer. These improvements will provide a strong reduction in the statistical uncertainties present in the ρ 0 -analysis and other analyses at HERMES. The Recoil Detector critically relies on its track reconstruction software to enable its capability to provide event level exclusive measurements. This tracking code is presented in detail. (orig.)

16th International Workshop on Polarized Sources, Targets, and Polarimetry (PSTP 2015)

CERN Document Server

2015-01-01

The Workshop on Polarized Sources, Targets and Polarimetry has been a tradition for more than 20 years, moving between Europe, USA and Japan. The XVIth International Workshop on Polarized Sources, Targets and Polarimetry (PSTP 2015) will take place at the Ruhr-University of Bochum, Germany. The workshop addresses the physics and technological challenges related to polarized gas/solid targets, polarized electron/positron/ion/neutron sources, polarimetry and their applications. will be published in Proceedings of Science

Improved techniques for the analysis of experiments with polarized targets. [1 to 2 GeV/c, polarization

Energy Technology Data Exchange (ETDEWEB)

Barrelet, E.

1975-06-01

An experiment was performed at the Bevatron to measure the polarization in the reaction ..pi../sup -/p ..-->.. ..pi../sup 0/n from a polarized target, at beam momenta between 1 and 2 GeV/c. Concentration is placed on the original aspects of our analysis, in particular: the geometrical reconstruction of the elastic events; the use of the high analyzing power of the reaction studied to probe the polarization of the target in magnitude and distribution; a study of the statistical estimation of the polarization parameter; a detailed study of the quasielastic background. (JFP)

A polarized sup 3 He internal target for storage rings

CERN Document Server

Poolman, H R; Bulten, H J; Doets, M; Ent, R; Ferro-Luzzi, M; Geurts, D G; Harvey, M; Mul, F A

2000-01-01

A polarized sup 3 He internal target was employed at the internal target facility of the Amsterdam electron Pulse Stretcher and Storage ring (AmPS) at the Dutch National Institute for Nuclear and High-Energy Physics (NIKHEF). The unique features of internal targets such as chemical and isotopic purity, high and rapidly reversible polarization, and the ability to manipulate the target spin orientation were successfully demonstrated. A nuclear polarization of 0.50 (0.42) at a sup 3 He gas flow of 1.0 (2.0)x10 sup 1 sup 7 at s sup - sup 1 could be obtained. Operation at a nominal flow of 1x10 sup 1 sup 7 at s sup - sup 1 resulted in a target thickness of 0.7x10 sup 1 sup 5 at cm sup - sup 2 at a target temperature of 17 K.

Calibration of the Fermilab E-704 polarized target

International Nuclear Information System (INIS)

Hill, D.A.

1992-01-01

This report lists the final, best estimate of the target polarization P T as a function of time for all of the periods during which scattering data were (or may have been) collected. The information under ''RUN'' refers to Δσ L -runs. The notation ''sfs'' stands for ''start of frozen spin,'' ''efs'' for ''end of frozen spin,'' ''→ la'' for ''go to large-aperture'' target magnet position, and ''nla'' for ''not large-aperture'' position, i.e., the target magnet is in ''polarizing'' position. Where the ''NOTE'' column is blank it means that all standard frozen-spin conditions were in effect: the target temperature was reduced and the magnet was in large-aperture position. The timing marks were developed on the basis of three criteria: (1) the availability of direct NMR data, (2) the inclusion of major Target and Run boundaries, and (3) the arbitrary inclusion of enough ''minor'' Run boundaries to shorten large timing gaps. The sign of the P T -values is given in the NMR convention: (+) corresponds to predominant occupation of the Zeeman ground state (the ''thermal'' NMR-signals are considered positive). Since the target magnet field pointed upstream, (+) corresponds to target spin antiparallel to the beam momentum. The estimated uncertainty on P T is ±6.5% (2σ), and the estimated uncertainty on the ratio of values for the two signs of polarization, P T (+)/PT(-), is ±4.3% (2σ)

Proton and neutron polarized targets for nucleon-nucleon experiments at SATURNE II

International Nuclear Information System (INIS)

Ball, J.; Combet, M.; Sans, J.L.; Benda, B.; Chaumette, P.; Deregel, J.; Durand, G.; Dzyubak, A.P.; Gaudron, C.; Lehar, F.; Janout, Z.; Khachaturov, B.A.

1996-01-01

A SATURNE polarized target has been used for nucleon-nucleon elastic scattering and transmission experiments for 15 years. The polarized proton target is a 70 cm 3 cartridge loaded with Pentanol-2. For polarized neutron target, two cartridges loaded with 6 LiD and 6 LiH are set in the refrigerator and can be quickly inserted in the beam. First experiments using 6 Li products in quasielastic pp or pn analyzing power measurements are compared with the same observables measured in a free nucleon-nucleon scattering using polarized proton targets. Angular distribution as a function of a kinematically conjugate angle and coplanarity in nucleon-nucleon scattering is shown for different targets. (author)

Optically pumped polarized 23Na vapor target for use in polarized ion source. Technical progress report

International Nuclear Information System (INIS)

Anderson, L.W.

1984-01-01

We are currently measuring relaxation times in an optically pumped 23 Na vapor target. Our research is directed toward improvements in the optically pumped Na vapor targets used for the production of polarized H - ions. In this progress report we review the properties of the optically pumped polarized H - ion source and especially the optically pumped Na vapor target employed in this source as well as discussing the progress of our research on relaxation times in an optically pumped Na vapor target. 30 references, 6 figures, 3 tables

A dual-optically-pumped polarized negative deuterium ion source

International Nuclear Information System (INIS)

Kinsho, M.; Mori, Y.; Ikegami, K.; Takagi, A.

1994-01-01

An optically pumped polarized H - source (OPPIS), which is based on the charge exchange between H + ions and electron-spin-polarized alkali atoms has been developed at KEK. Just by applying this scheme to a deuteron beam, it is difficult to obtain a highly vector polarized deuteron beam. To obtain highly vector polarized D - ions, we have developed a 'dual optical pumping type' of polarized D - source. With this scheme, a 100% vector nuclear-spin polarization for D - ions is possible in principle. In a preliminary experiment, a 60% of vector nuclear-spin polarized D - ions was obtained. (author)

Development of a hydrogen and deuterium polarized gas target for application in storage rings

International Nuclear Information System (INIS)

Haeberli, W.

1991-01-01

The present report contains the progress report for the second year of the 3-year budget period, and proposes work for the third year. Progress has been made on the two major components of the project, the tests of storage cells for polarized atoms under various operating conditions, and the construction of a new atomic beam source which conforms to the high vacuum requirements of storage rings

Deuterium isotope separation

International Nuclear Information System (INIS)

Benson, S.W.

1979-01-01

Deuterium-containing molecules are separated and enriched by exposing commercially available ethylene, vinyl chloride, 1,2-dichloroethane or propylene to the radiation of tuned infrared lasers to selectively decompose these compounds into enriched molecular products containing deuterium atoms. The deuterium containing molecules can be easily separated from the starting material by absorption, distillation or other simple chemical separation techniques and methods. After evaporation such deuterium containing molecules can be burned to form water with an enriched deuterium content or pyrolyzed to form hydrogen gas with an enriched deuterium content. (author)

Development of a medium energy polarized neutron facility

International Nuclear Information System (INIS)

Burzynski, S.; Gysin, C.; Henneck, R.; Jourdan, J.; Kohler, D.; Pickar, M.A.; Plattner, G.R.; Sick, I.; Berdoz, A.; Foroughi, F.; Nussbaum, Ch.; Stammbach, Th.

1984-01-01

By the end of 1983 the major construction work for the new polarized neutron source was completed. The source will provide an essentially monoenergetic beam of both polarized and unpolarized neutrons in the energy range from 20 MeV to 70 MeV. Intensities are expected to be approx. 2 x 10 5 neutrons/s.cm 2 per μA of incident proton beam. The polarization is expected to be approx. 0.2 and can be chosen to be either longitudinal or transverse. Protons from the Philips injector cyclotron are focussed onto a liquid deuterium target and produce neutrons via the 2 H(p,n)2p reaction at 0 0 . This process provides essentially monoenergetic neutrons of almost the same energy as the incoming protons. The zero production angle implies that the neutron polarization comes from the polarization of the proton beam only. This allows an easy and fast change of the neutron spin direction by selecting proton spin states in the polarized ion source (atomic beam type). (Auth.)

Optimum measurement and analysis of small polarization asymmetry in high-energy inelastic scattering using a polarized target

International Nuclear Information System (INIS)

Niinikoski, T.O.

1976-01-01

Optimum linear filter theory is employed for maximizing the signal-to-noise ratio in measurements of small polarization asymmetry in the presence of severe counting efficiency fluctuation, most likely to occur in high-energy inclusive and inelastic scattering experiments, using a polarized target. The r.m.s. error of the polarization asymmetry is obtained in closed form, allowing numeric optimization of the operation of the target. Guidelines are given for processing the record of data. (Auth.)

Tensor polarized deuteron targets for intermediate energy physics experiments

International Nuclear Information System (INIS)

Meyer, W.; Schilling, E.

1985-03-01

At intermediate energies measurements from a tensor polarized deuteron target are being prepared for the following reactions: the photodisintegration of the deuteron, the elastic pion-deuteron scattering and the elastic electron-deuteron scattering. The experimental situation of the polarization experiments for these reactions is briefly discussed in section 2. In section 3 the definitions of the deuteron polarization and the possibilities to determine the vector and tensor polarization are given. Present tensor polarization values and further improvements in this field are reported in section 4. (orig.)

A polarized solid {sup 3}He target for neutron transmission experiments

Energy Technology Data Exchange (ETDEWEB)

Keith, C.D. [North Carolina State Univ., Raleigh, NC (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Gould, C.R. [North Carolina State Univ., Raleigh, NC (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Haase, D.G. [North Carolina State Univ., Raleigh, NC (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Huffman, P.R. [Duke University, Durham, NC 27708-0308 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Roberson, N.R. [Duke University, Durham, NC 27708-0308 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Seely, M.L. [North Carolina State Univ., Raleigh, NC (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Tornow, W. [Duke University, Durham, NC 27708-0308 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Wilburn, W.S. [Duke University, Durham, NC 27708-0308 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)

1995-04-01

We describe the construction and operation of a solid {sup 3}He polarized nuclear target which we have used for measurements of the spin dependence of the n-{sup 3}He interaction at MeV energies. The target, which contains 0.4 mole of {sup 3}He was polarized to 38% at 12 mK in a field of 7 T. The target is suitable for nuclear physics measurements which are insensitive to the large magnetic field and produce beam heating of tenths of microwatts.We discuss refinements and paths to improved solid {sup 3}He targets at higher polarizations and lower fields. ((orig.)).

Michel Borghini as a Mentor and Father of the Theory of Polarization in Polarized Targets

Science.gov (United States)

de Boer, Wim

2016-02-01

This paper is a contribution to the memorial session for Michel Borghini at the Spin 2014 conference in Bejing, honoring his pivotal role for the development of polarized targets in high energy physics. Borghini proposed for the first time the correct mechanism for dynamic polarization in polarized targets using organic materials doped with free radicals. In these amorphous materials the spin levels are broadened by spin-spin interactions and g-factor anisotropy, which allows a high dynamic polarization of nuclei by cooling of the spin-spin interaction reservoir. In this contribution I summarize the experimental evidence for this mechanism. These pertinent experiments were done at CERN in the years 1971 - 1974, when I was a graduate student under the guidance of Michel Borghini. I finish by shortly describing how Borghini’s spin temperature theory is now applied in cancer therapy.

Kinetic simulation of neutron production in a deuterium z-pinch

International Nuclear Information System (INIS)

Mostrom, C.; Stygar, William A.; Thoma, Carsten; Welch, Dale Robert; Clark, R.E.; Leeper, Ramon Joe; Rose, David V.

2010-01-01

We have found computationally that, at sufficiently high currents, half of the neutrons produced by a deuterium z pinch are thermonuclear in origin. Early experiments below 1-MA current found that essentially all of the neutrons produced by a deuterium pinch are not thermonuclear, but are initiated by an instability that creates beam-target neutrons. Many subsequent authors have supported this result while others have claimed that pinch neutrons are thermonuclear. To resolve this issue, we have conducted fully kinetic, collisional, and electromagnetic simulations of the complete time evolution of a deuterium pinch. We find that at 1-MA pinch currents, most of the neutrons are, indeed, beam-target in origin. At much higher current, half of the neutrons are thermonuclear and half are beam-target driven by instabilities that produce a power law fall off in the ion energy distribution function at large energy. The implications for fusion energy production with such pinches are discussed.

Nuclear spin polarization of targets

International Nuclear Information System (INIS)

Happer, W.

1990-01-01

Lasers can be used to produce milligrams to grams of noble gas nuclei with spin polarizations in excess of 50%. These quantities are sufficient to be very useful targets in nuclear physics experiments. Alkali-metal atoms are used to capture the angular momentum of circularly polarized laser photons, and the alkali-metal atoms transfer their angular momentum to noble gas atoms in binary or three-body collisions. Non-radiative collisions between the excited alkali atoms and molecular quenching gases are essential to avoid radiation trapping. The spin exchange can involve gas-phase van der Waals molecules, consisting of a noble gas atom and an alkali metal atom. Surface chemistry is also of great importance in determining the wall-induced relaxation rates of the noble gases

Properties of thick GEM in low-pressure deuterium

International Nuclear Information System (INIS)

Lee, C S; Ota, S; Tokieda, H; Kojima, R; Watanabe, Y N; Uesaka, T

2014-01-01

Deuteron inelastic scattering (d, d') provides a promising spectroscopic tool to study nuclear incompressibility. In studies of deuteron inelastic scattering of unstable nuclei, measurements of low-energy recoiled particles is very important. In order to perform these measurements, we are developing a GEM-TPC based gaseous active target, called CAT (Center for nuclear study Active Target), operated with pure deuterium gas. The CAT has been tested with deuterium gas at 1 atm and 100-μm-thick GEMs. The low-pressure operation of CAT is planned in order to improve the detection capability for lower-energy recoil particles. A 400 μm-thick gas electron multiplier (THGEM) was chosen for the low-pressure operation of CAT. However, the properties of THGEM in low-pressure deuterium are currently undocumented. In this work, the performance of THGEM with low-pressure pure deuterium gas has been investigated. The effective gas gain of THGEM has been measured in various conditions using a 5.5-MeV 241 Am alpha source. The effective gas gain was measured for 0.2-, 0.3- and 0.4-atm deuterium gas and a gas gain of about 10 3 was achieved by a double THGEM structure at 0.2 atm. The maximum achieved gain decreased with increasing gas pressure. The dependences of the effective gas gain on the electric field strengths of the drift, transfer and induction regions were investigated. The gain stability as a function of time in hydrogen gas was also tested and a relaxation time of THGEM of about 60 hours was observed with a continuous irradiation of alpha particles, which is significantly longer than previous studies have reported. We have tried to evaluate the gas gain of THGEM in deuterium gas by considering only the Townsend ionization process; however, it turned out that more phenomenological aspects, such as transfer efficiency, should be included in the evaluation. The basic properties of THGEM in low-pressure deuterium have been investigated for the first time

Properties of thick GEM in low-pressure deuterium

Science.gov (United States)

Lee, C. S.; Ota, S.; Tokieda, H.; Kojima, R.; Watanabe, Y. N.; Uesaka, T.

2014-05-01

Deuteron inelastic scattering (d, d') provides a promising spectroscopic tool to study nuclear incompressibility. In studies of deuteron inelastic scattering of unstable nuclei, measurements of low-energy recoiled particles is very important. In order to perform these measurements, we are developing a GEM-TPC based gaseous active target, called CAT (Center for nuclear study Active Target), operated with pure deuterium gas. The CAT has been tested with deuterium gas at 1 atm and 100-μm-thick GEMs. The low-pressure operation of CAT is planned in order to improve the detection capability for lower-energy recoil particles. A 400 μm-thick gas electron multiplier (THGEM) was chosen for the low-pressure operation of CAT. However, the properties of THGEM in low-pressure deuterium are currently undocumented. In this work, the performance of THGEM with low-pressure pure deuterium gas has been investigated. The effective gas gain of THGEM has been measured in various conditions using a 5.5-MeV 241Am alpha source. The effective gas gain was measured for 0.2-, 0.3- and 0.4-atm deuterium gas and a gas gain of about 103 was achieved by a double THGEM structure at 0.2 atm. The maximum achieved gain decreased with increasing gas pressure. The dependences of the effective gas gain on the electric field strengths of the drift, transfer and induction regions were investigated. The gain stability as a function of time in hydrogen gas was also tested and a relaxation time of THGEM of about 60 hours was observed with a continuous irradiation of alpha particles, which is significantly longer than previous studies have reported. We have tried to evaluate the gas gain of THGEM in deuterium gas by considering only the Townsend ionization process; however, it turned out that more phenomenological aspects, such as transfer efficiency, should be included in the evaluation. The basic properties of THGEM in low-pressure deuterium have been investigated for the first time.

Polarization Calculation and Underwater Target Detection Inspired by Biological Visual Imaging

Directory of Open Access Journals (Sweden)

Jie Shen

2014-04-01

Full Text Available In challenging underwater environments, the polarization parameter maps calculated by the Stokes model are characterized by the high noise and error, harassing the underwater target detection tasks. In order to solve this problem, this paper proposes a novel bionic polarization calculation and underwater target detection method by modeling the visual system of mantis shrimps. This system includes many operators including a polarization-opposition calculation, a factor optimization and a visual neural network model. A calibration learning method is proposed to search the optimal value of the factors in the linear subtraction model. Finally, a six-channel visual neural network model is proposed to detect the underwater targets. Experimental results proved that the maps produced by the polarization-opposition parameter is more accurate and have lower noise than that produced by the Stokes parameter, achieving better performance in underwater target detection tasks.

Exclusive {rho}{sup 0} meson cross section ratios on deuterium and hydrogen targets

Energy Technology Data Exchange (ETDEWEB)

Osborne, A.G.S.

2006-08-15

The HERMES experiment is a large forward angle spectrometer located at the HERA accelerator ring at DESY, Hamburg. This thesis presents the analysis of the kinematic dependencies of {rho}{sup 0} vector meson production on hydrogen and deuterium targets. The relative gluon and quark contribution to the {rho}{sup 0} production amplitude is expected to depend on the kinematical variable x{sub Bj}, and by measuring the ratio of {rho}{sup 0} electroproduction cross sections on deuterium and hydrogen from HERMES data this dependence is confirmed. This thesis describes the methods used to extract the cross section ratio from the HERMES data taken between the years 1996 and 2000 and compares the results with the theoretical predictions. Until 2005 the missing mass resolution of the HERMES spectrometer was only sufficient to allow exclusivity at the level of a data sample. The HERMES Recoil Detector, installed in early 2006, is an upgrade which will augment the HERMES spectrometer by establishing exclusivity at the event level and therefore improving the resolution to which various kinematical variables may be reconstructed. Additionally, the Recoil Detector will contribute to the overall background suppression capability of the HERMES spectrometer. These improvements will provide a strong reduction in the statistical uncertainties present in the {rho}{sup 0}-analysis and other analyses at HERMES. The Recoil Detector critically relies on its track reconstruction software to enable its capability to provide event level exclusive measurements. This tracking code is presented in detail. (orig.)

Polarimetry of the polarized hydrogen deuteride HDice target under an electron beam

Energy Technology Data Exchange (ETDEWEB)

Laine, Vivien E. [Blaise Pascal Univ., Aubiere (France)

2013-10-01

The study of the nucleon structure has been a major research focus in fundamental physics in the past decades and still is the main research line of the Thomas Jefferson National Accelerator Facility (Jefferson Lab). For this purpose and to obtain statistically meaningful results, having both a polarized beam and a highly efficient polarized target is essential. For the target, this means high polarization and high relative density of polarized material. A Hydrogen Deuteride (HD) target that presents both such characteristics has been developed first at Brookhaven National Lab (BNL) and brought to the Hall B of Jefferson Lab in 2008. The HD target has been shown to work successfully under a high intensity photon beam (BNL and Jefferson Lab). However, it remained to be seen if the target could stand an electron beam of reasonably high current (nA). In this perspective, the target was tested for the first time in its frozen spin mode under an electron beam at Jefferson Lab in 2012 during the g14 experiment. This dissertation presents the principles and usage procedures of this HD target. The polarimetry of this target with Nuclear Magnetic Resonance (NMR) during the electron beam tests is also discussed. In addition, this dissertation also describes another way to perform target polarimetry with the elastic scattering of electrons off a polarized target by using data taken on helium-3 during the E97-110 experiment that occurred in Jefferson Lab's Hall A in 2003.

The Spin Structure of the Neutron Determined Using a Polarized He-3 Target

Energy Technology Data Exchange (ETDEWEB)

Middleton, H

2004-01-06

Described is a study of the internal spin structure of the neutron performed by measuring the asymmetry in spin-dependent deep inelastic scattering of polarized electrons from nuclear polarized {sup 3}He. Stanford Linear Accelerator experiment E142's sample of 400 million scattering events collected at beam energies between 19 and 26 GeV led to the most precise measurement of a nucleon spin structure function to date. The {sup 3}He target represents a major advance in polarized target technology, using the technique of spin exchange with optically pumped rubidium vapor to produce a typical {sup 3}He nuclear polarization of 34% in a 30cm long target cell with a gas density of 2.3 x 10{sup 20} cm{sup -3}. The target polarization was measured to {+-}7% using an Adiabatic Fast Passage NMR system calibrated with the thermal equilibrium polarization of the protons in a sample of water. The relatively high polarization and target thickness were the result of the development of large volume glass target cells which had inherent nuclear spin relaxation times for the {sup 3}He gas of as long as 70 hours. A target cell production procedure is presented which focuses on special glass blowing techniques to minimize surface interactions with the {sup 3}He nuclei and careful gas purification and vacuum system procedures to reduce relaxation inducing impurities.

Investigation of polarized-proton target materials by differential calorimetry: preliminary results

International Nuclear Information System (INIS)

Hill, D.A.; Hill, J.J.

1980-01-01

A simple differential calorimeter was designed and operated for an investigation of the thermodynamic properties of polarized target materials. The calibration and use of the calorimeter are discussed, after a brief exposition of our motivation for this work. The results of a preliminary study of target materials is presented with emphasis on the relevance of the glass state to dynamic polarization in chemically-doped targets

VME online system of the Bonn polarized nucleon targets and polarization measurements on NH3

International Nuclear Information System (INIS)

Thiel, W.

1991-02-01

The measurement of spin observables is the main purpose of the PHOENICS detector at the Bonn Electron Accelerator ELSA. Therefore a new frosen spin target was built allowing any spin orientation by means of two perpendicular holding fields and the use of a polarizing field up to 7 Tesla. With a vertical dilution refrigerator the polarization can be frozen at a temperature of 70 mK. This thesis describe a VME based control and monitor system for the various parts of this target. It mainly consists of a VIP processor together with different kinds of I/O and interface boards. Caused by its modular structure in hard- and software it can be easyly set up to control and monitor different hardware environments. A menu and command oriented user interface running on an ATARI computer allows a comfortable operation. Secondly the new NMR system is described in detail. It is based on the Liferpool module allowing a dispersion user interface running on an ATARI computer allows a comfortable operation. Secondly the new NMR system is described in detail. It is based on the Liverpool module allowing a dispersion free detection and a simple adjustment to different magnetic fields. A similar VME system takes care of all the necessary task for the polarization measurements. Fast optodecoupled analog I/O modules a e used as an interface to the NMR hardware. Finally the first measurements with this target are presented. Using NH 3 as target material and a polarizing field of 3.5 Tesla a proton polarization of +94% and -100% could be achieved. By lowering the magnetic field to 0.35 Tesla a superradiance effect was observed. (orig.)

Electron scattering with polarized targets at TESLA

International Nuclear Information System (INIS)

Anselmino, M.; Aschenauer, E.C.; Belostotski, S.

2000-11-01

Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e + arm of TESLA, can be directed onto a solid state target that may be either longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q 2 -dependence of the experimentally totally unknown quark transversity distributions that will complete the information on the nucleon's quark spin structure as relevant for high energy processes. Comparing their Q 2 -evolution to that of the corresponding helicity distributions constitutes an important precision test of the predictive power of QCD in the spin sector. Measuring transversity distributions and tensor charges allows access to the hitherto unmeasured chirally odd operators in QCD which are of great importance to understand the role of chiral symmetry. The possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics. (orig.)

Simulation and Automation of Microwave Frequency Control in Dynamic Nuclear Polarization for Solid Polarized Targets

Science.gov (United States)

Perera, Gonaduwage; Johnson, Ian; Keller, Dustin

2017-09-01

Dynamic Nuclear Polarization (DNP) is used in most of the solid polarized target scattering experiments. Those target materials must be irradiated using microwaves at a frequency determined by the difference in the nuclear Larmor and electron paramagnetic resonance (EPR) frequencies. But the resonance frequency changes with time as a result of radiation damage. Hence the microwave frequency should be adjusted accordingly. Manually adjusting the frequency can be difficult, and improper adjustments negatively impact the polarization. In order to overcome these difficulties, two controllers were developed which automate the process of seeking and maintaining the optimal frequency: one being a standalone controller for a traditional DC motor and the other a LabVIEW VI for a stepper motor configuration. Further a Monte-Carlo simulation was developed which can accurately model the polarization over time as a function of microwave frequency. In this talk, analysis of the simulated data and recent improvements to the automated system will be presented. DOE.

Deuterium and heavy water

International Nuclear Information System (INIS)

Vasaru, G.; Ursu, D.; Mihaila, A.; Szentgyorgyi, P.

1975-01-01

This bibliography on deuterium and heavy water contains 3763 references (1932-1974) from 43 sources of information. An author index and a subject index are given. The latter contains a list of 136 subjects, arranged in 13 main topics: abundance of deuterium , catalysts, catalytic exchange, chemical equilibria, chemical kinetics, deuterium and heavy water analysis, deuterium and heavy water properties, deuterium and heavy water separation, exchange reactions, general review, heavy water as moderator, isotope effects, synthesis of deuterium compounds

Target recognition of log-polar ladar range images using moment invariants

Science.gov (United States)

Xia, Wenze; Han, Shaokun; Cao, Jie; Yu, Haoyong

2017-01-01

The ladar range image has received considerable attentions in the automatic target recognition field. However, previous research does not cover target recognition using log-polar ladar range images. Therefore, we construct a target recognition system based on log-polar ladar range images in this paper. In this system combined moment invariants and backpropagation neural network are selected as shape descriptor and shape classifier, respectively. In order to fully analyze the effect of log-polar sampling pattern on recognition result, several comparative experiments based on simulated and real range images are carried out. Eventually, several important conclusions are drawn: (i) if combined moments are computed directly by log-polar range images, translation, rotation and scaling invariant properties of combined moments will be invalid (ii) when object is located in the center of field of view, recognition rate of log-polar range images is less sensitive to the changing of field of view (iii) as object position changes from center to edge of field of view, recognition performance of log-polar range images will decline dramatically (iv) log-polar range images has a better noise robustness than Cartesian range images. Finally, we give a suggestion that it is better to divide field of view into recognition area and searching area in the real application.

Feasibility study of a transversely polarized target in PANDA

Energy Technology Data Exchange (ETDEWEB)

Froehlich, Bertold [Helmholtz Institut Mainz (Germany)

2014-07-01

PANDA (Antiproton Annihilation at Darmstadt) is a key project at the Facility for Antiproton and Ion Research (FAIR), currently under construction at the GSI Darmstadt. PANDA is a state of the art detector for antiproton-proton fixed target experiments. A transversely polarized target in PANDA would allow the determination of the proton electromagnetic form factors in the time-like region with unprecedented accuracy and the first-time extraction of their imaginary part, opening a new window for investigating the nucleon structure. As a first step for achieving a transverse target polarization, the target region has to be shielded against the 2 T longitudinal magnetic flux from the solenoid of the PANDA spectrometer. We present numerical simulations and experimental results on intense magnetic flux shielding using a high temperature superconducting hollow cylinder.

Deuterium pass through target

International Nuclear Information System (INIS)

Alger, D.L.

1975-01-01

A neutron emitting target is described for use in neutron generating apparatus including a deuteron source and an accelerator vacuum chamber. The target consists of a tritium-containing target layer, a deuteron accumulation layer, and a target support containing passages providing communication between the accumulation layer and portions of the surface of the support exposed to the accelerator vacuum chamber. With this arrangement, deuterons passing through the target layer and implanting in and diffusing through the accumulation layer, diffuse into the communicating passages and are returned to the accelerator vacuum chamber. The invention allows the continuous removal of deuterons from the target in conventional water cooled neutron generating apparatus. Preferably, the target is provided with thin barrier layers to prevent undesirable tritium diffusion out of the target layer, as well as deuteron diffusion into the target layer

Spin Interactions and Cross-checks of Polarization in NH$_{3}$ Target

CERN Document Server

Kiselev, Yu; Doshita, N; Gautheron, F; Hess, Ch; Iwata, T; Koivuniemi, J; Kondo, K; Magnon, A; Mallot, G; Michigami, T; Meyer, W; Reicherz, G

2008-01-01

We study the magnetic structure of irradiated ammonia (NH$_{3}$) polarized by Dynamic Nuclear Polarization method at 0.2 K and at 2.5 T field. In this material, the electron spins, induced by ionizing radiation, couple $^{14}$N and $^{1}$H spins by the indirect spin-spin interaction. As a result, the local frequencies of $^{1}$H-spins are varied depending on $^{14}$N spin polarizations and lead to an asymmetry in the proton signal. This asymmetry allowes a good detection of $^{14}$N spins directly on the proton Larmor frequency. In the long COMPASS target at CERN, we use the cross-checks between spectral asymmetries and integral polarizations to decrease the relative error for longitudinal target polarizations up to $\\pm$2.0%.

The CERN polarized atomic hydrogen beam target project

International Nuclear Information System (INIS)

Kubischta, W.; Dick, L.

1990-01-01

The UA6-experiment at the CERN p bar p Colider is at present using an unpolarized hydrogen cluster target with a thickness up to 5.10 14 atoms/cm 2 . It is planned to replace this target by a polarized atomic hydrogen beam target with a thickness up to about 10 13 atoms/cm 2 . This paper discusses basic requirements and results of atom optical calculations

Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-15-1-0644 TITLE: Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells PRINCIPAL INVESTIGATOR: Chun-Ju...Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0644 5c. PROGRAM ELEMENT...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Cancer stem cells (CSCs), a cell population with acquired perpetuating self-renewal properties which

Pentanol-based target material with polarized protons

International Nuclear Information System (INIS)

Bunyatova, E.I.

1992-01-01

1-pentanol is a promising material for a target with polarized protons owing to its high resistance to radiation damage. To develop the target, the solutions of 1-pentanol or 2-pentanol with complexes of pentavalent chromium ware investigated. The material based EHBA-Cr(V) solution in a glass-like matrix, consisting of 1-pentanol, 3-pentanol and 1,2-propanediol, was proposed as a target material. It was investigated by the electron paramagnetic resonance and differential scanning calorimetry methods. 24 refs.; 3 figs.; 1 tab

Hyperfine structure of S-states of muonic deuterium

Directory of Open Access Journals (Sweden)

Alexey P. Martynenko

2015-09-01

Full Text Available On the basis of quasipotential method in quantum electrodynamics we calculate corrections of order $\\alpha^5$ and $\\alpha^6$ to hyperfine structure of $S$-wave energy levels of muonic deuterium. Relativistic corrections, effects of vacuum polarization in first, second and third orders of perturbation theory, nuclear structure and recoil corrections are taken into account. The obtained numerical values of hyperfine splitting $\\Delta E^{hfs}(1S=50.2814$ meV ($1S$ state and $\\Delta E^{hfs}(2S=6.2804$ meV ($2S$ state represent reliable estimate for a comparison with forthcoming experimental data of CREMA collaboration. The hyperfine structure interval $\\Delta_{12}=8\\Delta E^{hfs}(2S- \\Delta E^{hfs}(1S=-0.0379$ meV can be used for precision check of quantum electrodynamics prediction for muonic deuterium.

High magnetic field uniformity superconducting magnet for a movable polarized target

International Nuclear Information System (INIS)

Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

1998-01-01

The superconducting polarizing magnet was constructed for movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat with 'warm' aperture diameter of 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements using a NMR-magnetometer are given. The MPT set-up is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the Synchrophasotron of the Laboratory of High Energies (LHE), JINR, Dubna

Combining orthogonal polarization for elongated target detection with GPR

International Nuclear Information System (INIS)

Lualdi, Maurizio; Lombardi, Federico

2014-01-01

For an accurate imaging of ground penetrating radar data the polarization characteristics of the propagating electromagnetic (EM) wavefield and wave amplitude variations with antenna pattern orientation must be taken into account. For objects that show some directionality feature and cylindrical shape any misalignment between transmitter and target can strongly modify the polarization state of the backscattered wavefield, thus conditioning the detection capability of the system. Hints on the depolarization can be used to design the optimal GPR antenna survey to avoid omissions and pitfalls during data processing. This research addresses the issue of elongated target detection through a multi azimuth (or multi polarization) approach based on the combination of mutually orthogonal GPR data. Results from the analysis of the formal scattering problem demonstrate how this strategy can reach a scalar formulation of the scattering matrix and achieve a rotational invariant quantity. The effectiveness of the algorithm is then evaluated with a detailed field example showing results closely proximal to those obtained under the optimal alignment condition: detection is significantly improved and the risk of target missing is reduced. (paper)

COSY Juelich - a cooler synchrotron for unpolarized and polarized medium-energy studies

International Nuclear Information System (INIS)

Seyfarth, H.

2001-01-01

hypernuclei and the life time of the Λ hyperon in heavy nuclei. The external time-of-flight installation TOF, using the unpolarized and the polarized beam and a liquid hydrogen target is studying the production of hyperons, mesons, and Bremsstrahlung in proton-proton collisions. With liquid hydrogen and deuterium targets and various detector set-ups around the magnetic spectrograph Big Karl, the experiments GEM and MOMO investigate single and double meson production processes. After earlier unpolarized measurements of proton-proton elastic scattering excitation functions, the internal experiment EDDA now studies spin correlation parameters making use of the polarized COSY proton beam and a polarized atomic hydrogen beam source. COSY-II is using a hydrogen or deuterium cluster beam target and a COSY dipole magnet for momentum analysis to investigate single and double meson and hyperon production very near to the reaction thresholds. The special detector set-up of the magnetic spectrometer installation ANKE has allowed to measure cross sections for subthreshold production of K + mesons in the interaction of protons with thin carbon, copper, and gold strip targets. First unpolarized measurements on meson production in the proton-proton and proton-deuteron interaction and on proton-induced deuteron break-up with use of a cluster beam target will be extended by studies using the polarized proton beam and a polarized gas storage cell target. A polarized atomic beam source being ready for installation, will feed the storage cell. The talk will give a short overview on the research activities of the Forschungszentrum Juelich. It will present the characteristic features of the COSY-Juelich storage ring and the experimental research program with emphasis put onto that studying polarization effects

Targeting NCK-Mediated Endothelial Cell Front-Rear Polarity Inhibits Neovascularization.

Science.gov (United States)

Dubrac, Alexandre; Genet, Gael; Ola, Roxana; Zhang, Feng; Pibouin-Fragner, Laurence; Han, Jinah; Zhang, Jiasheng; Thomas, Jean-Léon; Chedotal, Alain; Schwartz, Martin A; Eichmann, Anne

2016-01-26

Sprouting angiogenesis is a key process driving blood vessel growth in ischemic tissues and an important drug target in a number of diseases, including wet macular degeneration and wound healing. Endothelial cells forming the sprout must develop front-rear polarity to allow sprout extension. The adaptor proteins Nck1 and 2 are known regulators of cytoskeletal dynamics and polarity, but their function in angiogenesis is poorly understood. Here, we show that the Nck adaptors are required for endothelial cell front-rear polarity and migration downstream of the angiogenic growth factors VEGF-A and Slit2. Mice carrying inducible, endothelial-specific Nck1/2 deletions fail to develop front-rear polarized vessel sprouts and exhibit severe angiogenesis defects in the postnatal retina and during embryonic development. Inactivation of NCK1 and 2 inhibits polarity by preventing Cdc42 and Pak2 activation by VEGF-A and Slit2. Mechanistically, NCK binding to ROBO1 is required for both Slit2- and VEGF-induced front-rear polarity. Selective inhibition of polarized endothelial cell migration by targeting Nck1/2 prevents hypersprouting induced by Notch or Bmp signaling inhibition, and pathological ocular neovascularization and wound healing, as well. These data reveal a novel signal integration mechanism involving NCK1/2, ROBO1/2, and VEGFR2 that controls endothelial cell front-rear polarity during sprouting angiogenesis. © 2015 American Heart Association, Inc.

Irradiation cryostat for LiH and LiD polarized solid targets

International Nuclear Information System (INIS)

Goertz, S.

1991-01-01

Scattering experiments with polarized nucleon targets are an important tool to understand the nuclear spin structure. Pion photoproduction experiments on polarized protrons and neutrons as well as measurements of the neutron and deuteron formfactors will be performed at ELSA. 7 LiH and 6 LiD seem to be attractive target materials for these experiments, because they offer high proton and deuteron polarisation, respectively. Expecially 6 LiD has further very important advantages compared to the common deuteron target materials as d-Butanol and ND 3 . This work describes the mechanism of DNP (Dynamic Nuclear Polarization) in LiH and LiD and gives a view on the nature of the so-called paramagnetic impurities in these materials. In order to maximize the nuclear polarization, the production of these radicals have to take place under well defined temperature conditions. Therefore the first version of an irradiation cryostat was built and tested in regard to its cooling power and temperature adjustment. (orig.)

Cryogenic control system of the large COMPASS polarized target

CERN Document Server

Gautheron, F; Baum, G; Berglund, P; Doshita, N; Görtz, S; Gustafsson, K K; Horikawa, N; Kisselev, Yu V; Koivuniemi, J H; Kondo, K; Meyer, Werner T; Reicherz, G

2004-01-01

The dilution refrigerator used to cool the large COMPASS polarized target is monitored through a PC running LabVIEW trademark 6.1 under Windows 2000 trademark . About 60 parameters of the target (temperatures, pressures, flow rates) are continuously plotted and checked. They are periodically recorded in an Oracle trademark database and in a data file. An alarm for every parameter can be individually activated and optionally connected to a GSM (Global System for Mobile Communication) delivery message system. A web server receives and publishes the online status of the target with online tables and graphics on a dedicated COMPASS polarized target information web site. A Siemens programmable logic controller (PLC) powered by an uninterruptable source keeps the cryogenic system safe and stable during the long beam periods by controlling valves and interlocks. This safety feature protects the dilution refrigerator against potential damages in case of power failure.

Detailed studies of a high-density polarized hydrogen gas target for storage rings

International Nuclear Information System (INIS)

Zapfe, K.; Brueckner, W.; Gaul, H.G.; Grieser, M.; Lin, M.T.; Moroz, Z.; Povh, B.; Rall, M.; Stechert, B.; Steffens, E.; Stenger, J.; Stock, F.; Tonhaeuser, J.; Montag, C.; Rathmann, F.; Fick, D.; Braun, B.; Graw, G.; Haeberli, W.

1996-01-01

A high-density target of polarized atomic hydrogen gas for applications in storage rings was produced by injecting atoms from an atomic beam source into a T-shaped storage cell. The influence of the internal gas target on electron-cooled beams of 27 MeV α-particles and 23 MeV protons in the Heidelberg Test Storage Ring has been studied in detail. Target polarization and target thickness were measured by means of 27 MeV α-particles. For hyperfine states 1+2 a target thickness of n=(0.96±0.04) x 10 14 H/cm 2 was achieved with the cell walls cooled to 100 K. Working with a weak magnetic holding field (∼5 G) the maximum target polarization was P T =0.84±0.02 when state 1 and P T =0.46±0.01 when states 1+2 were injected. The target polarization was found to be constant over a period of 3 months with a net charge of Q∼100 C passing the storage cell. (orig.)

A cryostat to hold frozen-spin polarized HD targets in CLAS: HDice-II

Energy Technology Data Exchange (ETDEWEB)

Lowry, M.M., E-mail: mlowry@jlab.org [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Bass, C.D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); D' Angelo, A. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Universita' di Roma ‘Tor Vergata’, and INFN Sezione di Roma ‘Tor Vergata’, Via della Ricerca Scientifica, 1, I-00133 Roma (Italy); Deur, A.; Dezern, G. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Hanretty, C. [University of Virginia, 1400 University Avenue, Charlottesville, VA 22903 (United States); Ho, D. [Carnegie-Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Kageya, T.; Kashy, D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Khandaker, M. [Norfolk State University, 700 Park Avenue, Norfolk, VA 23504 (United States); Laine, V. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Université Blaise Pascal, 34 Avenue Carnot, 63000 Clermont-Ferrand (France); O' Connell, T. [University of Connecticut, 115 N Eagleville Road, Storrs-Mansfield, CT 06269 (United States); Pastor, O. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Peng, P. [University of Virginia, 1400 University Avenue, Charlottesville, VA 22903 (United States); Sandorfi, A.M. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Sokhan, D. [Institut de Physique Nucleaire, Bat 100 – M053, Orsay 91406 (France); and others

2016-04-11

The design, fabrication, operation, and performance of a {sup 3/4}He dilution refrigerator and superconducting magnet system for holding a frozen-spin polarized hydrogen deuteride target in the Jefferson Laboratory CLAS detector during photon beam running is reported. The device operates both vertically (for target loading) and horizontally (for target bombardment). The device proves capable of maintaining a base temperature of 50 mK and a holding field of 1 T for extended periods. These characteristics enabled multi-month polarization lifetimes for frozen spin HD targets having proton polarization of up to 50% and deuteron up to 27%.

Deuterium-depleted water

International Nuclear Information System (INIS)

Stefanescu, Ion; Steflea, Dumitru; Saros-Rogobete, Irina; Titescu, Gheorghe; Tamaian, Radu

2001-01-01

Deuterium-depleted water represents water that has an isotopic content smaller than 145 ppm D/(D+H) which is the natural isotopic content of water. Deuterium depleted water is produced by vacuum distillation in columns equipped with structured packing made from phosphor bronze or stainless steel. Deuterium-depleted water, the production technique and structured packing are patents of National Institute of Research - Development for Cryogenics and Isotopic Technologies at Rm. Valcea. Researches made in the last few years showed the deuterium-depleted water is a biological active product that could have many applications in medicine and agriculture. (authors)

Development of high-performance alkali-hybrid polarized 3He targets for electron scattering

Science.gov (United States)

Singh, Jaideep T.; Dolph, P. A. M.; Tobias, W. A.; Averett, T. D.; Kelleher, A.; Mooney, K. E.; Nelyubin, V. V.; Wang, Yunxiao; Zheng, Yuan; Cates, G. D.

2015-05-01

Background: Polarized 3He targets have been used as effective polarized neutron targets for electron scattering experiments for over twenty years. Over the last ten years, the effective luminosity of polarized 3He targets based on spin-exchange optical pumping has increased by over an order of magnitude. This has come about because of improvements in commercially-available lasers and an improved understanding of the physics behind the polarization process. Purpose: We present the development of high-performance polarized 3He targets for use in electron scattering experiments. Improvements in the performance of polarized 3He targets, target properties, and operating parameters are documented. Methods: We utilize the technique of alkali-hybrid spin-exchange optical pumping to polarize the 3He targets. Spectrally narrowed diode lasers used for the optical pumping greatly improved the performance. A simulation of the alkali-hybrid spin-exchange optical pumping process was developed to provide guidance in the design of the targets. Data was collected during the characterization of 24 separate glass target cells, each of which was constructed while preparing for one of four experiments at Jefferson Laboratory in Newport News, Virginia. Results: From the data obtained we made determinations of the so-called X -factors that quantify a temperature-dependent and as-yet poorly understood spin-relaxation mechanism that limits the maximum achievable 3He polarization to well under 100%. The presence of the X -factor spin-relaxation mechanism was clearly evident in our data. Good agreement between the simulation and the actual target performance was obtained by including details such as off-resonant optical pumping. Included in our results is a measurement of the K -3He spin-exchange rate coefficient kseK=(7.46 ±0.62 ) ×10-20cm3/s over the temperature range 503 K to 563 K. Conclusions: In order to achieve high performance under the operating conditions described in this paper

Development of a new deuterium-deuterium (D-D) neutron generator for prompt gamma-ray neutron activation analysis.

Science.gov (United States)

Bergaoui, K; Reguigui, N; Gary, C K; Brown, C; Cremer, J T; Vainionpaa, J H; Piestrup, M A

2014-12-01

A new deuterium-deuterium (D-D) neutron generator has been developed by Adelphi Technology for prompt gamma neutron activation analysis (PGNAA), neutron activation analysis (NAA), and fast neutron radiography. The generator makes an excellent fast, intermediate, and thermal neutron source for laboratories and industrial applications that require the safe production of neutrons, a small footprint, low cost, and small regulatory burden. The generator has three major components: a Radio Frequency Induction Ion Source, a Secondary Electron Shroud, and a Diode Accelerator Structure and Target. Monoenergetic neutrons (2.5MeV) are produced with a yield of 10(10)n/s using 25-50mA of deuterium ion beam current and 125kV of acceleration voltage. The present study characterizes the performance of the neutron generator with respect to neutron yield, neutron production efficiency, and the ionic current as a function of the acceleration voltage at various RF powers. In addition the Monte Carlo N-Particle Transport (MCNP) simulation code was used to optimize the setup with respect to thermal flux and radiation protection. Copyright © 2014 Elsevier Ltd. All rights reserved.

Polarization reversal of proton spins in solid-state targets by superradiance effects

International Nuclear Information System (INIS)

Reichertz, L.A.

1991-02-01

Scattering experiments with polarized targets are prepared at the Bonn accelerator ELSA. The new Bonn frozen spin target (BOFROST) developed for real photon experiments at the PHOENICS detector has been tested in the laboratory. Proton polarization values of -99% and +94% in ammonia, -96% and +90% in butanol have been achieved at a magnetic field of 3.5 Tesla. At a temperature of 70 mK and a magnetic field of 0.35 Tesla a very fast spontaneous polarization reversal has been observed. This effect occured at negative polarization only and has been identified as a self-induced superradiance effect in the proton spin system. This work describes the polarization and relaxation measurements at BOFROST and detailed experiments concerning the superradiance effect. (orig.) [de

Characteristics of target polarization by laser ablation

Czech Academy of Sciences Publication Activity Database

Krása, Josef; Delle Side, D.; Giuffreda, E.; Nassisi, V.

2015-01-01

Roč. 33, č. 4 (2015), 601-605 ISSN 0263-0346 R&D Projects: GA ČR GAP205/12/0454; GA MŠk EE2.3.20.0279 Grant - others:LaserZdroj (OP VK 3)(XE) CZ.1.07/2.3.00/20.0279 Institutional support: RVO:68378271 Keywords : Target current in laser-produced plasmas * positive and negative target polarization * space structure of ion front Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.649, year: 2015

Wildcat: A commercial deuterium-deuterium tokamak reactor

International Nuclear Information System (INIS)

Evans, K.; Baker, C.C.; Barry, K.M.

1983-01-01

WILDCAT is a conceptual design of a catalyzed deuterium-deuterium tokamak commercial fusion reactor. WILDCAT utilizes the beneficial features of no tritium breeding, while not extrapolating unnecessarily from existing deuterium-tritium (D-T) designs. The reactor is larger and has higher magnetic fields and plasma pressures than typical D-T devices. It is more costly, but eliminates problems associated with tritium breeding and has tritium inventories and throughputs approximately two orders of magnitude less than typical D-T reactors. There are both a steady-state version with Alfven-wave current drive and a pulsed version. Extensive comparison with D-T devices has been made, and cost and safety analyses have been included. All of the major reactor systems have been worked out to a level of detail appropriate to a complete conceptual design

Feasibility study of a transversely polarized target in PANDA

Energy Technology Data Exchange (ETDEWEB)

Ahmadi, Heybat; Deiseroth, Malte; Khaneft, Dmitry; Noll, Oliver; Valente, Roserio; Zambrana, Manuel [Helmholtz-Institut Mainz (Germany); Johannes Gutenberg-Universitaet Mainz (Germany); Ahmed, Samer [Helmholtz-Institut Mainz (Germany); Capozza, Luigi; Dbeyssi, Alaa; Froehlich, Bertold; Lin, Dexu; Maas, Frank; Mora Espi, Maria Carmen; Morales Morales, Cristina; Rodriguez Pineiro, David; Zimmermann, Iris [Helmholtz-Institut Mainz (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany)

2015-07-01

The PANDA (Antiproton Annihilation at Darmstadt) spectrometer, located at the Facility for Antiproton and Ion Research (FAIR), is an excellent tool for exploring the nucleon structure. An unpolarized target allows the determination of the electromagnetic time-like form factor of the proton. An additional experiment in which the target is transversely polarized is necessary for the first-time extraction of their imaginary part. A transverse polarization requires the shielding of the 2 T longitudinal field from the PANDA-Solenoid at the target volume and an additional transverse holding field. We present results from our first experiment at the Institut fuer Kernphysik in Mainz on intense magnetic flux shielding using a BSCCO (bismuth strontium calcium copper oxide) thin-wall hollow cylinder at 4.2 K and a 1.4 T external magnetic field and compare this to numerical calculations.

On the large COMPASS polarized deuteron target

Czech Academy of Sciences Publication Activity Database

Ball, J.; Baum, G.; Doshita, N.; Finger Jr., M.; Finger, M.; Gautheron, F.; Goertz, S.; Hasegawa, T.; Heckmann, J.; Hess, C.; Horikawa, N.; Ishimoto, S.; Iwata, T.; Kisselev, Y.; Koivuniemi, J.H.; Kondo, K.; Le Goff, J.M.; Magnon, A.; Marchand, C.; Matsuda, T.; Meyer, W.; Reicherz, G.; Srnka, Aleš

2006-01-01

Roč. 56, Suppl. F (2006), F295-F305 ISSN 0011-4626 R&D Projects: GA MŠk ME 492 Institutional research plan: CEZ:AV0Z20650511 Keywords : COMPASS * polarized target * Dilution refrigerator Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.568, year: 2006

Effect of deposited tungsten on deuterium accumulation in beryllium in contact with atomic deuterium

Energy Technology Data Exchange (ETDEWEB)

Sharapov, V.M.; Gavrilov, L.E. [Institute of Physical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Kulikauskas, V.S.

1998-01-01

Usually ion or plasma beam is used for the experiment with beryllium which simulates the interaction of plasma with first wall in fusion devices. However, the use of thermal or subthermal atoms of hydrogen isotopes seems to be useful for that purpose. Recently, the authors have studied the deuterium accumulation in beryllium in contact with atomic deuterium. The experimental setup is shown, and is explained. By means of elastic recoil detection (ERD) technique, it was shown that in the exposure to D atoms at 740 K, deuterium is distributed deeply into the bulk, and is accumulated up to higher concentration than the case of the exposure to molecular deuterium. The depth and concentration of deuterium distribution depend on the exposure time, and those data are shown. During the exposure to atomic deuterium, oxide film grew on the side of a sample facing plasma. In order to understand the mechanism of deuterium trapping, the experiment was performed using secondary ion mass spectrometry (SIMS) and residual gas analysis (RGA). The influence that the tungsten deposit from the heated cathode exerted to the deuterium accumulation in beryllium in contact with atomic deuterium was investigated. These results are reported. (K.I.)

Evidence for neutron production in deuterium gas with a pyroelectric crystal without tip

International Nuclear Information System (INIS)

Tornow, W.; Shafroth, S. M.; Brownridge, J. D.

2008-01-01

We present evidence for the production of 2 H(d,n) 3 He neutrons in gaseous deuterium by using a pyroelectric crystal as positive ion accelerator. In contrast to previous studies, neutrons were generated without a tip attached to the crystal and without using a solid deuterated target. The deuterium gas provided both the projectile and target nuclei. On the average, 1 neutron/s was obtained in our ''hot fusion'' experimental setup. No neutrons were detected when a tip was used

Targeting NCK-Mediated Endothelial Cell Front-Rear Polarity Inhibits Neo-Vascularization

Science.gov (United States)

Dubrac, Alexandre; Genet, Gael; Ola, Roxana; Zhang, Feng; Pibouin-Fragner, Laurence; Han, Jinah; Zhang, Jiasheng; Thomas, Jean-Léon; Chedotal, Alain; Schwartz, Martin A.; Eichmann, Anne

2015-01-01

Background Sprouting angiogenesis is a key process driving blood vessel growth in ischemic tissues and an important drug target in a number of diseases, including wet macular degeneration and wound healing. Endothelial cells forming the sprout must develop front-rear polarity to allow sprout extension. The adaptor proteins Nck1 and 2 are known regulators of cytoskeletal dynamics and polarity, but their function in angiogenesis is poorly understood. Here we show that the Nck adaptors are required for endothelial cell front-rear polarity and migration downstream of the angiogenic growth factors VEGF-A and Slit2. Methods and Results Mice carrying inducible, endothelial-specific Nck1/2 deletions fail to develop front-rear polarized vessel sprouts and exhibit severe angiogenesis defects in the postnatal retina and during embryonic development. Inactivation of NCK1 and 2 inhibits polarity by preventing Cdc42 and Pak2 activation by VEGF-A and Slit2. Mechanistically, NCK binding to ROBO1 is required for both Slit2 and VEGF induced front-rear polarity. Selective inhibition of polarized endothelial cell migration by targeting Nck1/2 prevents hypersprouting induced by Notch or Bmp signaling inhibition, as well as pathological ocular neovascularization and wound healing. Conclusions These data reveal a novel signal integration mechanism involving NCK1/2, ROBO1/2 and VEGFR2 that controls endothelial cell front-rear polarity during sprouting angiogenesis. PMID:26659946

Target correlation and polarization effects on the electron impact ionization of He atoms

Energy Technology Data Exchange (ETDEWEB)

Saha, Hari P, E-mail: hps1@physics.ucf.edu [Physics Department, University of Central Florida, Orlando, FL 32816 (United States)

2011-03-28

We have reported here the results of our investigation of the effects of electron correlation and polarization of the target in the incident channel on the electron impact ionization of the helium atom. The triple differential cross section (TDCS) is calculated for 28.6 eV incident electron energy for the case when the two final-state outgoing electrons share 4.0 eV excess energy equally and unequally and leave in the opposite direction. The electron correlation and polarization of the He-target in the initial state are considered completely ab initio using the recently extended multiconfiguration Hartree-Fock method. The electron correlation between the two outgoing electrons in the final state is included through the variationally determined screening potential. It is found that both target correlation and polarization in the incident channel play an important role; the polarization has larger effect on the TDCS than the target correlation. We compared our results with available experimental and theoretical data.

Equipment and software for the experiment on polarized proton scattering on hydrogen and nuclei

International Nuclear Information System (INIS)

Buklej, A.E.; Govorun, N.N.; Zhurkin, V.V.

1980-01-01

Installation for the conduction of polarization measurements upon the beam of polarized protons with the 2.1 GeV/c momentum using ITEP synchrotron is described. The installation is designed for polarization measurement in elastic pp-scattering and asymmetry in summary (elastic and inelastic without meson production) scattering of polarized protons upon nuclei in the angle range up to 180 mrad, as well as polarization in elastic pn-scattering. The installation consists of 18 two-coordinate magnetostriction wire spark chambers (s.c.), emitting counters, the system of veto-counters surrounding the target, liquid hydrogen or (deuterium) target and magnet to conduct pulse analysis of scattered particles in the background measurements. Primary processing of the material is conducted on the basis of modernized programs using the M-220 and BESM-6 computers. With a help of the experimental installation described asymmetry measurement on hydrogen, Li, C, Al, Ca have been conducted. The prospect of use of the method described to separate elastic reactions in the range of very small momentum transmitted, where the background of inelastic interactions can be decreased to the negligibly low level, for precise measurement of elastic reactions cross sections and the study of polarization phenomena in the range of coulomb interference is underlined [ru

Quasielastic nucleon scattering using polarized beams and targets

International Nuclear Information System (INIS)

Haeusser, O.

1990-07-01

Inelastic scattering of polarized intermediate energy nucleons to continuum nuclear states is discussed with emphasis on recent results. Spin momentum correlations of protons in polarized targets of 3 He were observed for the first time. Complete spin observables in (p,p') show effects of the nuclear spin-isospin response and of an NN interaction modified by the nuclear medium. A comparison of Gamow Teller and isovector M1 giant resonance strengths in the sd shell provides evidence for large meson exchange current effects in the M1. (Author) (37 refs., 2 tabs., 9 figs.)

Effect of Coulomb screening on deuterium-deuterium fusion cross-section

International Nuclear Information System (INIS)

Wang Shunjin

1991-01-01

The popular Gamow formula for the deuterium-deuterium fusion cross-section is generalized to take into account the Coulomb screening effect. The generalized formula has been used to discuss the fusion process occurring in the metal medium

Deuterium exchange between hydrofluorocarbons and amines

International Nuclear Information System (INIS)

Hammond, W.B.; Bigeleisen, J.; Tuccio, S.A.

1983-01-01

The invention consists of a process for obtaining a compound enriched in deuterium which comprises the known method of exposing a gaseous hydrofluorocarbon to infrared laser radiation of a predetermined frequency to selectively cause a chemical reaction involving hydrofluorocarbon molecules containing deuterium without substantially affecting hydrofluorocarbon molecules not containing deuterium, thereby producing, as reaction products, a compound enriched in deuterium and hydrofluorocarbon depleted in deuterium; combined with a new method, which comprises enriching the deuterium content of the depleted hydrofluorocarbon by contacting the depleted hydrofluorocarbon with an alkali metal amide and an amine having a concentration of deuterium at least that which will yield an increase in deuterium concentration of the hydrofluorocarbon upon equilibration, whereby the amine becomes depleted in deuterium

Cryogenic polarized-target facility. Progress report, July 1, 1981-June 30, 1982

International Nuclear Information System (INIS)

Gould, C.R.; Haase, D.G.

1982-01-01

The goal of this three-year research project is to build a cryogenically polarized target facility for measuring total neutron cross sections for polarized neutrons incident on polarized nuclei. The components of the system have been assembled at TUNL during the current contract period. These include the dilution-refrigerator support assembly, the dilution-refrigerator itself, the dewar, the beam line, the shielding cave for the neutron source, and the neutron-detector shield and rolling-cart assembly. The dilution refrigerator is presently undergoing testing at liquid-nitrogen and liquid-helium temperatures. Experiments with aluminum and copper targets are scheduled for the coming contract period

Producing deuterium-enriched products

International Nuclear Information System (INIS)

1980-01-01

A method of producing an enriched deuterium product from a gaseous feed stream of mixed hydrogen and deuterium, comprises: (a) combining the feed stream with gaseous bromine to form a mixture of the feed stream and bromine and exposing the mixture to an electrical discharge effective to form deuterium bromide and hydrogen bromide with a ratio of D/H greater than the ratio of D/H in the feed stream; and (b) separating at least a portion of the hydrogen bromide and deuterium bromide from the mixture. (author)

Polarized photoproduction from nuclear targets with arbitrary spin and relation to deep inelastic scattering

International Nuclear Information System (INIS)

Hoodbhoy, P.; Massachusetts Inst. of Tech., Cambridge; Quaid-i-Azam Univ., Islamabad

1990-01-01

Inclusive photo-production from polarized targets of arbitrary spin is analyzed by using multipoles. The Drell-Hearn-Gerasimov sum rule, which was originally fromulated for spin-1/2 targets, is generalized to all spins and multipoles, and shown to have some interesting consequences. Measurements to test the new rules, or to derive nuclear structure information from them, could be incorporated into existing plans at electron accelerator facilities. Finally, the possible relevance of these generalized sum rules to sum rules measurable in polarized lepton-polarized target deep inelastic inclusive scattering is discussed. (orig.)

A study of lithium deuteride as a material for a polarized target

CERN Document Server

Bültmann, S; Day, D B; Fatemi, R D; Gardner, B; Harris, C M; Johnson, J R; Mccarthy, J S; McKee, P M; Meyer, Werner T; Penttilae, S I; Ponikvar, E; Rijllart, A; Rondon, Oscar A; Lorant, S S; Tobias, W A; Trentalange, S; Zhu, H; Zihlmann, B; Zimmermann, D

1999-01-01

Experiment E155 at the Stanford Linear Accelerator Center (SLAC) measured the spin-dependent structure of the proton and neutron, using for the first time sup 6 LiD as the polarized deuteron target material in a high-energy electron beam. This compound provides a significantly higher dilution factor than any other solid deuteron target material currently used in high-energy physics experiments. Results of the polarization behavior of the sup 6 LiD target material before and after exposure to the 50 GeV/c electron beam used in E155 are presented.

On the possibility of using lithium-6 deuteride, irradiated with gas discharge plasma in a target with polarized nuclei of deuterium and lithium

International Nuclear Information System (INIS)

Bunyatova, E.I.; Bubnov, N.N.; Solodovnikov, S.P.

1991-01-01

A target with polarized nuclei made on the basis of irradiated lithium-6 deuteride is of great interest for carrying out investigations in elementary particle physics. Up to now high-energy electrons have been used for generation of F-centers in 6 LiD. It is shown that one can, in principle, use ultraviolet irradiation and gas discharge plasma for generation of F-centers in 6 LiD. Both types of irradiation cause electron paramagnetic resonance signals from conductance electrons of lithium and form F-centers in 6 LiD. It seems possible to obtain the necessary samples by exposing 6 LiD to the gas discharge plasma. 9 refs.; 2 figs

Test of time-reversal invariance at COSY

Energy Technology Data Exchange (ETDEWEB)

Valdau, Yury [Helmholtz Institut fuer Strahlen- und Kernphysik, Bonn Univ. (Germany); National Research Center ' ' Kurchatov Institute' ' Petersburg Nuclear Physics Institute B.P. Konstantinov, Gatchina (Russian Federation); Eversheim, Dieter [Helmholtz Institut fuer Strahlen- und Kernphysik, Bonn Univ. (Germany); Lorentz, Bernd [Forschungszentrum Juelich, Institute fuer Kernphysik (Germany)

2016-07-01

The experiment to test the Time Reversal Invariance at Cosy (TRIC) is under the preparation by the PAX collaboration. It is planned to improve present limit on the T-odd P-even interaction by at least one order of magnitude using a unique genuine null observable available in double polarized proton-deuteron scattering. The TRIC experiment is planned as a transmission experiment using a tensor polarized deuterium target placed at the internal target place of the Cooler-Synchrotron COSY-Juelich. Total double polarized cross section will be measured observing a beam current change due to the interaction of a polarized proton beam with an internal tensor polarized deuterium target from the PAX atomic beam source. Hence, in this experiment COSY will be used as an accelerator, detector and ideal zero degree spectrometer. In addition to the high intensity polarized proton beam and high density polarized deuterium target, a new high precision beam current measurement system will be prepared for the TRIC experiment. In this report status of all the activities of PAX collaboration towards realization of the TRIC experiment will be presented.

Polarization observables for strangeness photoproduction on a frozen spin target with CLAS at Jefferson Lab

International Nuclear Information System (INIS)

Fegan, Stuart

2012-01-01

The FROST experiment at Jefferson Lab used the CLAS detector in Hall B with the intention of performing a complete measurement of polarization observables associated with strangeness photoproduction, in combination with data from previous JLab experiments. This was achieved by utilizing the FROST polarized target in conjunction with polarized photon beams, allowing direct measurement of beam-target double polarization observables. By studying strangeness reactions, such as γp → K + Λ 0 , it may be possible to find 'missing' baryon resonances, predicted by symmetric quark models but not observed in previous experiments, whose results are consistent with the di-quark model. It is thought these 'missing' resonances remain undiscovered because they have different coupling strengths for different reaction channels, such as the strangeness reactions, whereas the current data is dominated by studies of pN reactions. Observing these resonances therefore has important implications for our knowledge of the excited states of nucleons, and the models predicting the quark interactions within them. The G polarization observable is one of the beam-target double polarization observables, associated with a longitudinally polarized target and a linearly polarized photon beam, and its measurement for the strangeness reaction γp → K + Λ 0 is the focus of the work presented.

Lamb shift in the muonic deuterium atom

Energy Technology Data Exchange (ETDEWEB)

Krutov, A. A.; Martynenko, A. P. [Samara State University, Pavlov street 1, 443011, Samara (Russian Federation); Samara State University, Pavlov Street 1, 443011, Samara, Russia and Samara State Aerospace University named after academician S.P. Korolyov, Moskovskoye Shosse 34, 443086, Samara (Russian Federation)

2011-11-15

We present an investigation of the Lamb shift (2P{sub 1/2}-2S{sub 1/2}) in the muonic deuterium ({mu}D) atom using the three-dimensional quasipotential method in quantum electrodynamics. The vacuum polarization, nuclear-structure, and recoil effects are calculated with the account of contributions of orders {alpha}{sup 3}, {alpha}{sup 4}, {alpha}{sup 5}, and {alpha}{sup 6}. The results are compared with earlier performed calculations. The obtained numerical value of the Lamb shift at 202.4139 meV can be considered a reliable estimate for comparison with forthcoming experimental data.

First use of a laser-driven polarized H/D target at the IUCF cooler

International Nuclear Information System (INIS)

Bailey, K.; Brack, J.; Cadman, R. V.; Cummings, W. J.; Fedchak, J.; Fox, B.; Gao, H.; Grosshauser, C.; Holt, R. J.; Jones, C.; Kinney, E.; Kowalczyk, R.; Lu, Z.-T.; Miller, M. A.; Nagengast, W.; Owen, B.; Rith, K.; Schmidt, F.; Schulte, E.; Sowinski, J.; Sperisen, F.; Stenger, J.; Thorsland, E.; Williamson, S.

1997-01-01

The HERMES Laser-Driven Target Task Force (Argonne, Erlangen and Illinois) is charged with developing a polarized H/D target for use in the HERA ring at DESY. Rapid progress was made in the beginning of 1996, leading us to the decision to test the target in a realistic experimental environment. In particular, polarizations of 0.6 and flows above 10 18 atoms·s -1 have been achieved on the bench. The laser-driven target and a simple detector system are currently installed in Cooler storage ring at the Indiana University Cyclotron Facility in order to test its applicability to nuclear physics experiments. Target polarizations are being measured using the rvec H(p, p) and rvec D(p, p) reactions. Initial tests were reasonably successful and the target is well along toward becoming viable for nuclear physics

Neutron production with mixture of deuterium and krypton in Sahand Filippov type plasma focus facility

International Nuclear Information System (INIS)

Mohammadi, M.A.; Sobhanian, S.; Rawat, R.S.

2011-01-01

This Letter reports the order of magnitude enhancement in neutron yield from Sahand plasma focus device with krypton seeded deuterium operation. The highest average neutron yield of 2.2x10 9 neutrons per shot was achieved at 1.00 Torr deuterium with 3% krypton which is higher than the best average neutron yield of 3.18x10 8 neutrons per shot for pure deuterium operation. Estimation of average neutron energy showed that the maximum and minimum average energies are 2.98±0.6 MeV at 16 kV in 0.25 Torr deuterium with 3% Kr and 2.07±0.2 MeV at 18 kV operation in 0.5 Torr deuterium with 3% Kr, respectively. The anisotropy of neutron emission from Sahand DPF showed that the neutrons are produced mainly by beam-target mechanisms. -- Highlights: → The highest average neutron yield of 2.2x10 9 neutrons per shot was achieved at mixture of deuterium and krypton. → In the krypton seeding of deuterium also anisotropy of neutron emission deuterium is found. → The krypton seeding of deuterium made the neutron emission more reliable over wider operating pressure ranges.

Deuterium depth profiling in JT-60U W-shaped divertor tiles by nuclear reaction analysis

International Nuclear Information System (INIS)

Hayashi, T.; Ochiai, K.; Masaki, K.; Gotoh, Y.; Kutsukake, C.; Arai, T.; Nishitani, T.; Miya, N.

2006-01-01

Deuterium concentrations and depth profiles in plasma-facing graphite tiles used in the divertor of JAERI Tokamak-60 Upgrade (JT-60U) were investigated by nuclear reaction analysis (NRA). The highest deuterium concentration of D/ 12 C of 0.053 was found in the outer dome wing tile, where the deuterium accumulated probably through the deuterium-carbon co-deposition. In the outer and inner divertor target tiles, the D/ 12 C data were lower than 0.006. Additionally, the maximum (H + D)/ 12 C in the dome top tile was estimated to be 0.023 from the results of NRA and secondary ion mass spectroscopy (SIMS). Orbit following Monte-Carlo (OFMC) simulation showed energetic deuterons caused by neutral beam injections (NBI) were implanted into the dome region with high heat flux. Furthermore, the surface temperature and conditions such as deposition and erosion significantly influenced the accumulation process of deuterium. The deuterium depth profile, scanning electron microscope (SEM) observation and OFMC simulation indicated the deuterium was considered to accumulate through three processes: the deuterium-carbon co-deposition, the implantation of energetic deuterons and the deuterium diffusion into the bulk

QED corrections in deep-inelastic scattering from tensor polarized deuteron target

CERN Document Server

Gakh, G I

2001-01-01

The QED correction in the deep inelastic scattering from the polarized tensor of the deuteron target is considered. The calculations are based on the covariant parametrization of the deuteron quadrupole polarization tensor. The Drell-Yan representations in the electrodynamics are used for describing the radiation real and virtual particles

Deuterium migration and trapping in uranium and uranium dioxide during D+ implantation

International Nuclear Information System (INIS)

Lewis, M.B.

1980-01-01

Uranium and UO 2 have been implanted with deuterium ions in the energy range 30-85 keV. Subsequently, the near surface regions (100-90000 Angstroem) of these samples were quantitatively profiled for deuterium oxygen using the method of ion beam microanalysis. Mean ranges and widths of the implanted ions were measured and compared with theoretical predictions. Fully oxidized samples were compared with those having only thin oxide films on their surfaces. While the deuterium appeared to migrate during its implantation in uranium, little or no migration appeared either during or after implantation in UO 2 . Further measurements suggest that thin surface oxide films strongly trap the deuterium migrating beneath the surface. It is suggested that the electronic energy loss of the ion beam lowers the effective activation energy for the formation of OD bonds near the target surface. (orig.)

A polarized {sup 3}He target for the photon beam at MAMI

Energy Technology Data Exchange (ETDEWEB)

Krimmer, J., E-mail: j.krimmer@ipnl.in2p3.fr [Institut fuer Physik, Johannes Gutenberg-Universitaet, Staudinger Weg 7, 55099 Mainz (Germany); Institut de Physique Nucleaire de Lyon, 4 rue Enrico Fermi, 69622 Villeurbanne cedex (France); Aguar Bartolome, P.; Ahrens, J. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Johann-Joachim-Becher-Weg 45, 55099 Mainz (Germany); Altieri, S. [INFN Sezione di Pavia, Pavia (Italy); Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia, Pavia (Italy); Arends, H.J. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Johann-Joachim-Becher-Weg 45, 55099 Mainz (Germany); Heil, W.; Karpuk, S.; Otten, E.W. [Institut fuer Physik, Johannes Gutenberg-Universitaet, Staudinger Weg 7, 55099 Mainz (Germany); Pedroni, P. [INFN Sezione di Pavia, Pavia (Italy); Salhi, Z. [Institut fuer Physik, Johannes Gutenberg-Universitaet, Staudinger Weg 7, 55099 Mainz (Germany); Thomas, A. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Johann-Joachim-Becher-Weg 45, 55099 Mainz (Germany)

2011-08-21

A polarized {sup 3}He target has been installed for the first time inside the 4{pi} Crystal Ball detector at the tagged photon beam of the MAinz MIcrotron (MAMI). It has been demonstrated that the system works reliably and that the polarization losses during handling of the polarized gas are under control. Initial polarization values up to 70% and total relaxation times up to 20 h could be obtained during a first test beam time devoted to the measurement of the double polarized photoabsorption cross-section in the {Delta}(1232) baryon resonance region.

Deuterium - depleted water. Achievements and perspectives

International Nuclear Information System (INIS)

Titescu, Gh.; Stefanescu, I.; Saros-Rogobete, I.

2001-01-01

Deuterium - depleted water represents water that has an isotopic content lower than 145 ppm D/(D+H) which is the natural isotopic content of water. The research conducted at ICSI Ramnicu Valcea, regarding deuterium - depleted water were completed by the following patents: - technique and installation for deuterium - depleted water production; - distilled water with low deuterium content; - technique and installation for the production of distilled water with low deuterium content; - mineralized water with low deuterium content and technique to produce it. The gold and silver medals won at international salons for inventions confirmed the novelty of these inventions. Knowing that deuterium content of water has a big influence on living organisms, beginning with 1996, the ICSI Ramnicu Valcea, deuterium - depleted water producer, co-operated with Romanian specialized institutes for biological effects' evaluation of deuterium - depleted water. The role of natural deuterium in living organisms was examined by using deuterium - depleted water instead of natural water. These investigations led to the following conclusions: 1. deuterium - depleted water caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tone and vascular reactivity produced by the deuterium - depleted water persists after the removal of the vascular endothelium; -2. animals treated with deuterium - depleted water showed an increase of the resistance both to sublethal and to lethal gamma radiation doses, suggesting a radioprotective action by the stimulation of non-specific immune defence mechanism; 3, deuterium - depleted water stimulates immune defence reactions, represented by the opsonic, bactericidal and phagocyte capacity of the immune system, together with increase in the numbers of polymorphonuclear neutrophils; 4. investigations regarding artificial

Hydrogen and deuterium NMR of solids by magic-angle spinning

International Nuclear Information System (INIS)

Eckman, R.R.

1982-10-01

The nuclear magnetic resonance of solids has long been characterized by very large specral broadening which arises from internuclear dipole-dipole coupling or the nuclear electric quadrupole interaction. These couplings can obscure the smaller chemical shift interaction and make that information unavailable. Two important and difficult cases are that of hydrogen and deuterium. The development of cross polarization, heteronuclear radiofrequency decoupling, and coherent averaging of nuclear spin interactions has provided measurement of chemical shift tensors in solids. Recently, double quantum NMR and double quantum decoupling have led to measurement of deuterium and proton chemical shift tensors, respectively. A general problem of these experiments is the overlapping of the tensor powder pattern spectra of magnetically distinct sites which cannot be resolved. In this work, high resolution NMR of hydrogen and deuterium in solids is demonstrated. For both nuclei, the resonances are narrowed to obtain liquid-like isotropic spectra by high frequency rotation of the sample about an axis inclined at the magic angle, β/sub m/ = Arccos (3/sup -1/2/), with respect to the direction of the external magnetic field. For deuterium, the powder spectra were narrowed by over three orders of magnitude by magic angle rotation with precise control of β. A second approach was the observation of deuterium double quantum transitions under magic angle rotation. For hydrogen, magic angle rotation alone could be applied to obtain the isotropic spectrum when H/sub D/ was small. This often occurs naturally when the nuclei are semi-dilute or involved in internal motion. In the general case of large H/sub D/, isotropic spectra were obtained by dilution of 1 H with 2 H combined with magic angle rotation. The resolution obtained represents the practical limit for proton NMR of solids

Radiation damage and deuterium trapping in deuterium-ion-irradiated Fe–9Cr alloy

Energy Technology Data Exchange (ETDEWEB)

Iwakir, Hirotomo, E-mail: iwakiri@edu.u-ryukyu.ac.jp [Faculty and Graduate School of Education, University of the Ryukyus, Nishihara, Okinawa 903-0213 (Japan); Tani, Munechika [Interdisciplinary Graduate School of Engineering Sciences, Kyusyu University, Kasuga, Fukuoka 816-8580 (Japan); Watanabe, Yoshiyuki [Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Yoshida, Naoaki [Research Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

2014-01-15

Thermal desorption of deuterium (D{sub 2}) from deuterium-ion (D{sub 2}{sup +})-irradiated Fe–9Cr was correlated with the microstructural evolution of the alloy during irradiation with 8-keV D{sub 2}{sup +} ions following annealing to determine the retention and desorption behavior of the implanted deuterium and to identify effective traps for them, particularly at high temperature. After irradiation at 573 K, a new desorption stage formed between 650 and 1100 K at higher fluences, and cavities were observed using transmission electron microscopy. The total amount of trapped deuterium following irradiation with a fluence of 3.0 × 10{sup 22} ions/m{sup 2} was 6.8 × 10{sup 17} D{sub 2}/m{sup 2}, or approximately 0.007%. These results indicate that the deuterium atoms recombined to form D{sub 2} molecules at the surfaces of the cavities.

On feasibility of the experiments with a polarized deuteron beam and a polarized target at Charles University in relation with polarized fusion

International Nuclear Information System (INIS)

Plis, Yu.A.

2001-01-01

There is an interest in the problem of polarized fusion with the neutron-free d 3 He reaction. Up to now, the experimental data on the cross sections of two dd reactions, which produce neutrons at once or through secondary dt reaction, are absent for polarized deuterons. There is a relatively cheap way to carry out the experiments with polarized deuterons at the Charles University in Prague. A polarized deuteron beam with energy from 100 keV up to approximately 1 MeV may be produced on the Van de Graaff accelerator by the channeling of a deuteron beam through magnetized Ni single crystal foil, according M. Kaminsky [Phys. Rev. Lett. 23, 819 (1969)]. This method permits to produce a polarized deuteron beam of an energy ≤1 MeV with a current of ∼1 nA, vector polarization P 3 up to 2/3 and tensor polarization P 33 =0. It will be necessary to modify the existing polarized target at Charles University for work with a low energy deuteron beam [N. S. Borisov et al., Nucl. Instr. and Meth. A 345, 421 (1994)

Neutron scattering with deuterium labeling reveals the nature of complexes formed by Ca{sup 2+}-binding proteins and their regulatory targets

Energy Technology Data Exchange (ETDEWEB)

Trewhella, J. [Los Alamos National Laboratory, NM (United States)

1994-12-01

Small-angle neutron scattering with deuterium labeling is extremely useful for studying the structures of complex biomolecular assemblies in solution. The different neutron scattering properties of their isotopes of hydrogen combines with the ability to uniformly label biomolecules with deuterium allow one to characterize the structures and relative dispositions of the individual components of an assembly using methods of {open_quotes}contrast variation.{close_quotes} We have applied these techniques to studies of the evolutionarily related dumbbell-shaped Ca{sup 2+}-binding proteins calmodulin and troponin C and their interactions with the target proteins whose activities they regulate. Ca{sup 2+} is one of the simplest of nature`s messengers used in the communication pathways between physiological stimulus and cellular response. The signaling mechanism generally involves Ca{sup 2+} binding to a protein and inducing a conformational change that transmits a signal to modify the activity of a specific target protein. Ca{sup 2+} is thus important in the regulation of a diverse array of intracellular responses, including neurotransmitter release, muscle contraction, the degradation of glycogen to glucose to generate energy, microtubule assembly, membrane phosphorylation, etc. It is the conformational language of the Ca{sup 2+} induced signal transduction that we have sought to understand because of its central importance to biochemical regulation and, hence, to healthy cellular function.

Distillation of hydrogen isotopes for polarized HD targets

Energy Technology Data Exchange (ETDEWEB)

Ohta, T., E-mail: takeshi@rcnp.osaka-u.ac.jp [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan); Bouchigny, S. [IN2P3, Institut de Physique Nucleaire, F-91406 Orsay (France); CEA LIST, BP6-92265 Fontenay-aux-Roses, CEDEX (France); Didelez, J.-P. [IN2P3, Institut de Physique Nucleaire, F-91406 Orsay (France); Fujiwara, M. [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan); Fukuda, K. [Kansai University of Nursing and Health Sciences, Shizuki Awaji 656-2131 (Japan); Kohri, H.; Kunimatsu, T.; Morisaki, C.; Ono, S. [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan); Rouille, G. [IN2P3, Institut de Physique Nucleaire, F-91406 Orsay (France); Tanaka, M. [Kobe Tokiwa University, Ohtani-cho 2-6-2, Nagata, Kobe 653-0838 (Japan); Ueda, K.; Uraki, M.; Utsuro, M. [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan); Wang, S.Y. [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Department of Physics, National Kaohsiung Normal University, Kaohsiung 824, Taiwan (China); Yosoi, M. [Research Center for Nuclear Physics, Osaka University, Mihogaoka 10-1, Ibaraki, Osaka 567-0047 (Japan)

2012-02-01

We have developed a new cryogenic distillation system to purify Hydrogen-Deuteride (HD) gas for polarized HD targets in LEPS experiments at SPring-8. A small amount of ortho-H{sub 2} ({approx}0.01%) in the HD gas plays an important role in efficiently polarizing the HD target. Since there are 1-5% impurities of H{sub 2} and D{sub 2} in commercially available HD gases, it is necessary to purify the HD gas up to {approx}99.99%. The distillation system is equipped with a cryogenic distillation unit filled with many small stainless steel cells called 'Heli-pack'. The distillation unit consists of a condenser part, a rectification part, and a reboiler part. The unit is kept at the temperature of 17-21 K. The Heli-pack has a large surface area that makes a good contact between gases and liquids. An amount of 5.2 mol of commercial HD gas is fed into the distillation unit. Three trials were carried out to purify the HD gas by changing temperatures (17.5 K and 20.5 K) and gas extraction speeds (1.3 ml/min and 5.2 ml/min). The extracted gas was analyzed using a gas analyzer system combining a quadrupole mass spectrometer with a gas chromatograph. One mol of HD gas with a purity better than 99.99% has been successfully obtained for the first time. The effective NTP (Number of Theoretical Plates), which is an indication of the distillation performances, is obtained to be 37.2{+-}0.6. This value is in good agreement with a designed value of 37.9. The HD target is expected to be efficiently polarized under a well-controlled condition by adding an optimal amount of ortho-H{sub 2} to the purified HD gas.

Polarization imaging enhancement for target vision through haze

Science.gov (United States)

Wu, Hai-Ying; Zhang, San-Xi; Li, Jie; LI, Bin; Tang, Zi-li; Liu, Biao; Jia, Wen-Wu

2016-10-01

Haze, fog, and smoke are turbid medium in the atmosphere which usually degrade viewing condition of outdoor scenes. The resulted images lose contrast and color fidelity with serious degradation. Due to loss of large detailed information of measured scene, it will usually lead to invalid detection and measurement. The suspended particles in the atmosphere and the scene being measured give rise to polarization changes by their reflection. In the process of reflection, absorption and scattering, the object itself can be determined by its own polarization characteristics. Based on this point, we proposed an approach for target vision through haze. This approach is based on the polarization differences between the scene being measured and the scattering background to move the haze effects. It can realize a great visibility enhancement and enable the scene rendering even if imaged under restricted viewing conditions with low polarization. In this work, the detailed theoretical operation principle is presented. A validating imaging system is established and the corresponding experiment is carried out. We present the experimental results of haze-free image of scene with recovered high contrast. This method also can be used to effectively enhance the imaging performance of any other optical system.

Apparatus for producing laser targets

International Nuclear Information System (INIS)

Jarboe, T.R.; Baker, W.R.

1975-01-01

This patent relates to an apparatus and method for producing deuterium targets or pellets of 25u to 75u diameter. The pellets are sliced from a continuously spun solid deuterium thread at a rate of up to 10 pellets/second. The pellets after being sliced from the continuous thread of deuterium are collimated and directed to a point of use, such as a laser activated combustion or explosion chamber wherein the pellets are imploded by laser energy or laser produced target plasmas for neutral beam injection

Method of deuterium isotope separation and enrichment

International Nuclear Information System (INIS)

Benson, S.W.

1978-01-01

A method of separating deuterium, i.e., heavy hydrogen, from certain naturally occurring sources using tuned infrared lasers to selectively decompose specified classes of organic molecules (i.e., RX) into enriched molecular products containing deuterium atoms is described. The deuterium containing molecules are easily separated from the starting material by absorption, distillation or other simple chemical separation techniques and methods. After evaporation such deuterium containing molecules can be burned to form water with an enriched deuterium content or pyrolyzed to form hydrogen gas with an enriched deuterium content. The undecomposed molecules and the other reaction products which are depleted of their deuterium containing species can be catalytically treated, preferably using normal water, to restore the natural abundance of deuterium and such restored molecules can then be recycled

[Development of a hydrogen and deuterium polarized gas target for application in storage rings]: Progress report

International Nuclear Information System (INIS)

Haeberli, W.

1989-01-01

This paper briefly discusses the following topics: the Wisconsin test facility for storage cells; results of target tests; the new UHV target test system; funding request for a new atomic beam system; and planning of storage ring experiments

A Precision Measurement of the Neutron Spin Structure Functions Using a Polarized HE-3 Target

International Nuclear Information System (INIS)

Smith, T

2003-01-01

This thesis describes a precision measurement of the neutron spin dependent structure function, g 1 n (x). The measurement was made by the E154 collaboration at SLAC using a longitudinally polarized, 48.3 GeV electron beam, and a 3 He target polarized by spin exchange with optically pumped rubidium. A target polarization as high as 50% was achieved. The elements of the experiment which pertain to the polarized 3 He target will be described in detail in this thesis. To achieve a precision measurement, it has been necessary to minimize the systematic error from the uncertainty in the target parameters. All of the parameters of the target have been carefully measured, and the most important parameters of the target have been measured using multiple techniques. The polarization of the target was measured using nuclear magnetic resonance techniques, and has been calibrated using both proton NMR and by measuring the shift of the Rb Zeeman resonance frequency due to the 3 He polarization. The fraction of events which originated in the 3 He, as measured by the spectrometers, has been determined using a physical model of the target and the spectrometers. It was also measured during the experiment using a variable pressure 3 He reference cell in place of the polarized 3 He target. The spin dependent structure function g 1 n (z) was measured in the Bjorken x range of 0.014 2 of 5 (GeV/c) 2 . One of the primary motivations for this experiment was to test the Bjorken sum rule. Because the experiment had smaller statistical errors and a broader kinematic coverage than previous experiments, the behavior of the spin structure function g 1 n (x) could be studied in detail at low values of the Bjorken scaling variable x. It was found that g 1 n (x) has a strongly divergent behavior at low values of x, calling into question the methods commonly used to extrapolate the value of g 1 n (x) to low x. The precision of the measurement made by the E154 collaboration at SLAC puts a tighter

Electron spin resonance and its implication on the maximum nuclear polarization of deuterated solid target materials

International Nuclear Information System (INIS)

Heckmann, J.; Meyer, W.; Radtke, E.; Reicherz, G.; Goertz, S.

2006-01-01

ESR spectroscopy is an important tool in polarized solid target material research, since it allows us to study the paramagnetic centers, which are used for the dynamic nuclear polarization (DNP). The polarization behavior of the different target materials is strongly affected by the properties of these centers, which are added to the diamagnetic materials by chemical doping or irradiation. In particular, the ESR linewidth of the paramagnetic centers is a very important parameter, especially concerning the deuterated target materials. In this paper, the results of the first precise ESR measurements of the deuterated target materials at a DNP-relevant magnetic field of 2.5 T are presented. Moreover, these results allowed us to experimentally study the correlation between ESR linewidth and maximum deuteron polarization, as given by the spin-temperature theory

Recent developments in laser-driven polarized sources

International Nuclear Information System (INIS)

Young, L.; Coulter, K.P.; Holt, R.J.; Kinney, E.R.; Kowalczyk, R.S.; Potterveld, D.H.; Zghiche, A.

1990-01-01

Recent progress in the performance of laser-driven sources of polarized hydrogen and deuterium is described. The current status of the prototype source, I = 2.5 x 10 17 s -1 , polarization = 0.29 (including atomic fraction), is comparable to classical Stern-Gerlach sources. A scheme to improve source performance by approximately an order of magnitude, using a combination of optical-pumping spin-exchange and RF transitions, is outlined. 8 refs., 2 figs., 1 tab

Influence of laser-target interaction on the polarization of a CO2-laser

International Nuclear Information System (INIS)

Du, K.; Herziger, G.; Loosen, P.; Seelig, W.

1988-01-01

Laser materials processing shows a special peculiarity compared to other customary techniques: the generally reflecting target introduces optical feedback into the system. This feedback changes the mode properties of the laser radiation according to the targets dynamics. The authors report on one of these aspects of laser-target interaction resulting in the change of the polarization of the incident light. Based of rate equations, a theoretical model is presented in this paper that allows the calculation of this change with respect of the target properties, yielding a simple relation for the two orthogonal planes of polarization of a laser mode. This relation turns out to be linearly dependent of a function ψ (t) which describes the optical feedback. The relation holds for target reflexions of up to 10% and four times larger than τ 2 x τ 2 /τ 1 - τ 2 (where τ 1 , τ 2 are the time constants of the passive resonator for the two orthogonal planes of polarization). The model offers a method for the modulation for the modulation of laser radiation without change of frequency or intensity. It might also be of interest for high-power CO 2 laser cutting and welding of metals

The tagged photon beam polarization of the jet target experiment

International Nuclear Information System (INIS)

Bianchi, N.; Muccifora, V.

1989-01-01

The applicability of the residual electron selection method to the tagging method of the jet target laboratory has been studied. With this end in view the behaviour of the polarized bremsstrahlung cross section in the range considered has been analysed, while the polarization increase by means of the RES has been evaluated. The vertical conditions of the focusing of the tagging spectrometer as a function of energy have been determined. Finally the gamma beam density and the tagging efficiency have been calculated

Photoproduction of η mesons from the neutron: Cross sections and double polarization observable E

Energy Technology Data Exchange (ETDEWEB)

Witthauer, L.; Dieterle, M.; Challand, T.; Kaeser, A.; Keshelashvili, I.; Krusche, B.; Rostomyan, T.; Walford, N.K.; Werthmueller, D. [University of Basel, Department of Physics, Basel (Switzerland); Afzal, F.; Beck, R.; Boese, S.; Funke, C.; Gottschall, M.; Gruener, M.; Hammann, C.; Hartmann, J.; Hoffmeister, P.; Honisch, C.; Kaiser, D.; Kalinowsky, H.; Kalischewski, F.; Klassen, P.; Koop, K.; Lang, M.; Mahlberg, P.; Mueller, J.; Muellers, J.; Piontek, D.; Schmidt, C.; Seifen, T.; Sokhoyan, V.; Spieker, K.; Thiel, A.; Thoma, U.; Urban, M.; Pee, H. van; Walther, D.; Wendel, C.; Winnebeck, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn, Bonn (Germany); Anisovich, A.V.; Bayadilov, D.; Nikonov, V.; Sarantsev, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn, Bonn (Germany); Petersburg Nuclear Physics Institute, National Research Centre ' ' Kurchatov Institute' ' , Gatchina (Russian Federation); Bantes, B.; Dutz, H.; Eberhardt, H.; Elsner, D.; Ewald, R.; Fornet-Ponse, K.; Frommberger, F.; Goertz, S.; Hammann, D.; Hannappel, J.; Hillert, W.; Jude, T.; Kammer, S.; Kleber, V.; Klein, F.; Schmieden, H. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Bichow, M.; Meyer, W.; Reicherz, G. [Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (Germany); Brinkmann, K.T.; Gutz, E. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn, Bonn (Germany); Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Crede, V. [Florida State University, Department of Physics, Tallahassee, FL (United States); Friedrich, S.; Makonyi, K.; Metag, V.; Nanova, M. [Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Gridnev, A.; Lopatin, I. [Petersburg Nuclear Physics Institute, National Research Centre ' ' Kurchatov Institute' ' , Gatchina (Russian Federation); Wilson, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn, Bonn (Germany); Florida State University, Department of Physics, Tallahassee, FL (United States); Collaboration: The CBELSA/TAPS Collaboration

2017-03-15

Results from measurements of the photoproduction of η mesons from quasifree protons and neutrons are summarized. The experiments were performed with the CBELSA/TAPS detector at the electron accelerator ELSA in Bonn using the η → 3π{sup 0} → 6γ decay. A liquid deuterium target was used for the measurement of total cross sections and angular distributions. The results confirm earlier measurements from Bonn and the MAMI facility in Mainz about the existence of a narrow structure in the excitation function of γn → nη. The current angular distributions show a forward-backward asymmetry, which was previously not seen, but was predicted by model calculations including an additional narrow P{sub 11} state. Furthermore, data obtained with a longitudinally polarized, deuterated butanol target and a circularly polarized photon beam were analyzed to determine the double polarization observable E. Both data sets together were also used to extract the helicity-dependent cross sections σ{sub 1/2} and σ{sub 3/2}. The narrow structure in the excitation function of γn → nη appears associated with the helicity-1/2 component of the reaction. (orig.)

The polarized atomic-beam target for the EDDA experiment and the time-reversal invariance test at COSY

International Nuclear Information System (INIS)

Eversheim, P.D.; Altmeier, M.; Felden, O.

1996-01-01

For the the EDDA experiment, which was set up to measure the p-vector - p-vector excitation function during the acceleration ramp of the cooler synchrotron COSY at Juelich, a polarized atomic-beam target was designed regarding the restrictions imposed by the geometry of the EDDA detector. Later, when the time-reversal invariance experiment is to be performed, the EDDA detector will serve as efficient internal polarimeter and the source has to deliver tensor polarized deuterons. The modular design of this polarized atomic-beam target that allows to meet these conditions are discussed in comparison to other existing polarized atomic-beam targets. (orig.)

Parity violation in inelastic scattering of polarized electrons

International Nuclear Information System (INIS)

Prescott, C.Y.

1978-10-01

Parity nonconservation was observed in the inelastic scattering of longitudinally polarized electrons from an unpolarized deuterium target at 19.4 and 22.2 GeV. An asymmetry A = (sigma/sub R/ - sigma/sub L)/(sigma/sub R/ + sigma/sub L/) = (-9.5 +- 1.6) x 10 -5 Q 2 , Q 2 in (GeV/c) 2 was found for values of Q 2 near 1.4. The statistical and systematic errors are each about 9 percent of the measured asymmetry. This result is consistent with predictions from the standard Weinberg--Salam SU(2) x U(1) model. Using the simple quark-parton model of the nucleon, the value sin 2 theta/sub W/ = 0.20 +- 0.03 is obtained. 21 references

Photoproduction of neutral kaons on a liquid deuterium target in the threshold region

Czech Academy of Sciences Publication Activity Database

Tsukada, K.; Takahashi, T.; Watanabe, T.; Fujii, Y.; Futatsukawa ., K.; Hashimoto, O.; Hirose, K.; Ito, K.; Kameoka, S.; Kanda, H.; Maeda, K.; Matsumura, A.; Miura, Y.; Myiase, H.; Nakamura, S. N.; Nomura, H.; Nonaka, K.; Osaka, T.; Okayasu, Y.; Tamura, H.; Tsubota, H.; Ukai, M.; Yamauchi, H.; Wakamatsu, M.; Ishikawa, T.; Kinoshita, T.; Miyahara, F.; Nakabayashi, T.; Shimizu, H.; Tamae, T.; Yamazaki, H.; Sasaki, A.; Konno, O.; Bydžovský, Petr; Sotona, Miloslav

2008-01-01

Roč. 78, - (2008), 014001/1-014000/10 ISSN 0556-2813 R&D Projects: GA ČR GA202/05/2142 Institutional research plan: CEZ:AV0Z10480505 Keywords : neutral kaons * liguit deuterium * treshold region Subject RIV: BE - Theoretical Physics Impact factor: 3.124, year: 2008

A Precision Measurement of the Neutron Spin Structure Functions Using a Polarized HE-3 Target

Energy Technology Data Exchange (ETDEWEB)

Smith, T

2003-11-05

This thesis describes a precision measurement of the neutron spin dependent structure function, g{sub 1}{sup n}(x). The measurement was made by the E154 collaboration at SLAC using a longitudinally polarized, 48.3 GeV electron beam, and a {sup 3}He target polarized by spin exchange with optically pumped rubidium. A target polarization as high as 50% was achieved. The elements of the experiment which pertain to the polarized {sup 3}He target will be described in detail in this thesis. To achieve a precision measurement, it has been necessary to minimize the systematic error from the uncertainty in the target parameters. All of the parameters of the target have been carefully measured, and the most important parameters of the target have been measured using multiple techniques. The polarization of the target was measured using nuclear magnetic resonance techniques, and has been calibrated using both proton NMR and by measuring the shift of the Rb Zeeman resonance frequency due to the {sup 3}He polarization. The fraction of events which originated in the {sup 3}He, as measured by the spectrometers, has been determined using a physical model of the target and the spectrometers. It was also measured during the experiment using a variable pressure {sup 3}He reference cell in place of the polarized {sup 3}He target. The spin dependent structure function g{sub 1}{sup n}(z) was measured in the Bjorken x range of 0.014 < x < 0.7 with an average Q{sup 2} of 5 (GeV/c){sup 2}. One of the primary motivations for this experiment was to test the Bjorken sum rule. Because the experiment had smaller statistical errors and a broader kinematic coverage than previous experiments, the behavior of the spin structure function g{sub 1}{sup n}(x) could be studied in detail at low values of the Bjorken scaling variable x. It was found that g{sub 1}{sup n}(x) has a strongly divergent behavior at low values of x, calling into question the methods commonly used to extrapolate the value of g

Effect of Beam Scanning on Target Polarization Scattering Matrix Observed by Fully Polarimetric Phased-array Radar

Directory of Open Access Journals (Sweden)

Li Mianquan

2016-04-01

Full Text Available The polarization feature of a fully Polarimetric Phased-Array Radar (PPAR antenna varies according to the beam-scanning angle, thereby introducing two problems on the target Polarization Scattering Matrix (PSM measurement. First, the antenna polarization basis is defined within the vertical cross-section of an electromagnetic wave propagation direction, and the polarization basis of each beam direction angle is not identical, resulting in the PSM of a fixed-posture target observed by PPAR being not identical for different beam-scanning angles. Second, the cross polarization of the PPAR antenna increases with increasing beamscanning angle, resulting in a crosstalk among the elements of PSM observed by PPAR. This study focuses on the analysis of the abovementioned two aspects of the effect of beam scanning on target PSM observed by PPAR. The results will establish a more accurate observation of the equation for the precision PSM measurement of PPAR.

Radiative electron rearrangement and polarization in target K x-ray spectra

International Nuclear Information System (INIS)

Jamison, K.A.

1978-01-01

Two topics in the atomic physics of ion-atom collisions are studied. The first is an investigation of a free-atom decay process that is shown to be a two-electron one-photon decay. This two-electron decay requires an initial state with multiple inner-shell vacancies that has a high probability of creation in ion-atom collisions. Because this decay promotes one electron to a higher shell while allowing the other to fall to a lower shell, it is referred to as radiative electron rearrangement (RER). The investigation of this process includes the experimental study of the x-ray spectra region approx. 150 eV below the characteristic Kα 1 2 target radiation in third period elements when bombarded by various ion beams in the energy range 1 to 2 MeV/amu. Theoretical calculations of the transition energies, line strengths, and line widths are performed to verify the origin of the RER lines. The second topic of consideration is the study of the polarization of Kα satellite radiation from targets of Al and Si. It is shown that the polarization, which is observed experimentally with a curved-crystal polarimeter, is due to the nonstatistical population of the magnetic substates created in specific ion-atom collisions. Further, the polarization of the RER lines is studied. The connection between the polarization of the normal Kα satellite radiation and the polarization of the RER lines adds final proof to their origin as two-electron one-photon transitions

H-mode WEST tungsten divertor operation: deuterium and nitrogen seeded simulations with SOLEDGE2D-EIRENE

Directory of Open Access Journals (Sweden)

G. Ciraolo

2017-08-01

Full Text Available Simulations of WEST H-mode divertor scenarios have been performed with SOLEDGE2D-EIRENE edge plasma transport code, both for pure deuterium and nitrogen seeded discharge. In the pure deuterium case, a target heat flux of 8 MW/m2 is reached, but misalignment between heat and the particle outflux yields 50 eV plasma temperature at the target plates. With nitrogen seeding, the heat and particle outflux are observed to be aligned so that lower plasma temperatures at the target plates are achieved together with the required high heat fluxes. This change in heat and particle outflux alignment is analysed with respect to the role of divertor geometry and the impact of vertical vs horizontal target plates on neutrals spreading.

The polarized atomic-beam target for the EDDA experiment and the time-reversal invariance test at COSY

Science.gov (United States)

Eversheim, P. D.; Altmeier, M.; Felden, O.

1997-02-01

For the the EDDA experiment, which was set up to measure the p¯-p¯ excitation function during the acceleration ramp of the cooler synchrotron COSY at Jülich, a polarized atomic-beam target was designed regarding the restrictions imposed by the geometry of the EDDA detector. Later, when the time-reversal invariance experiment is to be performed, the EDDA detector will serve as efficient internal polarimeter and the source has to deliver tensor polarized deuterons. The modular design of this polarized atomic-beam target that allows to meet these conditions will be discussed in comparison to other existing polarized atomic-beam targets.

Deuterium abundance, from ultraviolet to visible

International Nuclear Information System (INIS)

Hebrard, Guillaume

2000-01-01

In the frame of the standard Big Bang model, the primordial abundance of deuterium is the most sensitive to the baryonic density of the Universe. It was synthesized only during the primordial nucleosynthesis few minutes after the Big Bang and no other standard mechanism is able to produce any further significant amount. On the contrary, since deuterium is burned up within stars, its abundance D/H decreases along cosmic evolution. Thus, D/H measurements constrain Big Bang and galactic chemical evolution models. There are three samples of deuterium abundances: primordial, proto-solar and interstellar. Each of them is representative of a given epoch, respectively about 15 Gyrs past, 4.5 Gyrs past and present epoch. Although the evolution of the deuterium abundance seems to be qualitatively understood, the measurements show some dispersion. Present thesis works are linked to deuterium interstellar abundance measurements. Such measurements are classically obtained from spectroscopic observations of the hydrogen and deuterium Lyman series in absorption in the ultraviolet spectral range, using space observatories. Results presented here were obtained with the Hubble Space Telescope and FUSE, which has recently been launched. Simultaneously, a new way to observe deuterium has been proposed, in the visible spectral range from ground-based telescopes. This has led to the first detections and the identification of the deuterium Balmer series, in emission in HII regions, using CFHT and VLT telescopes. (author) [fr

Deuterium-depleted water. Romanian achievements and perspective

International Nuclear Information System (INIS)

Stefanescu, Ion; Saros-Rogobete, Irina; Titescu, Gheorghe

2001-01-01

Deuterium-depleted water has an isotopic content smaller than 145 ppm D/(D+H) which is the natural isotopic content of water. Beginning with 1996 ICSI Rm. Valcea, deuterium-depleted water producer, co-operated with Romanian specialized institutes for biological effect's evaluation of deuterium-depleted water. These investigations lead to the following conclusions: - Deuterium-depleted water caused a tendency towards the increase of the basal tonus, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tonus and vascular reactivity produced by the deuterium-depleted water persist after the removal of the vascular endothelium; - Animals treated with deuterium-depleted water showed an increase of the resistance both to sublethal and to lethal gamma radiation doses, suggesting a radioprotective action; - Deuterium-depleted water stimulates immune defence reactions and increases the numbers of polymorphonuclear neutrophils; - Investigations regarding artificial reproduction of fish with deuterium-depleted water fecundated solutions confirmed favourable influence in embryo growth stage and resistance in subsequent growth stages; - It was studied germination, growth and quantitative character's variability in plants; one can remark the favourable influence of deuterium-depleted water on biological process in plants in various ontogenetic stages; - The deuterium depletion in seawater produces the diminution of the water spectral energy related to an increased metabolism of Tetraselmis Suecica. (authors)

Physics in the GeV region with polarized targets in electron storage rings

International Nuclear Information System (INIS)

Holt, R.J.

1988-01-01

There is evidence from the D(γ,p)n reaction that the meson-exchange model is failing in the GeV region. Surprisingly, it appears that the new (Dγ,p)n data favor the energy dependence of the nuclear chromodynamics model rather that of the meson-exchange model. Application of the polarization method to electron scattering studies is in its infancy, and it is potentially a very powerful technique. The internal target method coupled with laser-driven polarized targets should represent an important tool for nuclear physics

OMEGA polar-drive target designs

International Nuclear Information System (INIS)

Radha, P. B.; Marozas, J. A.; Marshall, F. J.; Shvydky, A.; Collins, T. J. B.; Goncharov, V. N.; McKenty, P. W.; Sangster, T. C.; Skupsky, S.; McCrory, R. L.; Meyerhofer, D. D.

2012-01-01

Low-adiabat polar-drive (PD) [Skupsky et al., Phys. Plasmas 11, 2763 (2004)] implosion designs for the OMEGA [Boehly et al., Opt. Commun. 133, 495 (1997)] laser are described. These designs for cryogenic deuterium–tritium and warm plastic shells use a temporal laser pulse shape with three pickets followed by a main pulse [Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)]. The designs are at two different on-target laser intensities, with different in-flight aspect ratios (IFARs). These designs permit studies of implosion energetics and target performance closer to ignition-relevant intensities (∼7 × 10 14 W/cm 2 at the quarter-critical surface, where nonlocal heat conduction and laser–plasma interactions can play an important role) but at lower values of IFAR ∼ 22 or at lower intensity (∼3 × 10 14 W/cm 2 ) but at a higher IFAR (IFAR ∼ 32, where shell instability can play an important role). PD geometry requires repointing of laser beams to improve shell symmetry. The higher-intensity designs optimize target performance by repointing beams to a lesser extent, compensating for the reduced equatorial drive by increasing the energies of the repointed beams. They also use custom beam profiles that improve equatorial illumination at the expense of irradiation at higher latitudes. These latter designs will be studied when new phase plates for the OMEGA Laser System, corresponding to the custom beam profiles, are obtained.

A high efficiency bunching system for the TUNL polarized ion source

International Nuclear Information System (INIS)

Wender, S.A.

1981-01-01

The problem of producing pulsed beams without large beam current losses has been the topic of recent interest particularly in areas where large peak currents are required. In addition, an efficient bunching system will allow the use of pulsed beams when source intensities are limited. The motivation for the development of the authors' high efficiency bunching system arose from their strong interest in neutron physics and the desire to extend their research with experiments requiring polarized neutrons. A common method for the production of polarized neutrons is to bombard a deuterium gas cell with a polarized deuteron beam. The D(→d,n) 3 He reaction has a large cross section and the outgoing neutron has a polarization of approximately 60 % in the energy range between 6 MeV to 16 Mev. Most experiments which involve the detection of neutrons use time-of-flight techniques to determine the neutron energy. An excellent way of providing time-of-flight information is to use pulsed beams. To be useful for time of flight experiments beam pulses must be on the order of a few nanoseconds wide. In addition there must be sufficient time between beam bursts to allow the reaction neutrons to travel from the target to the detector before the next beam burst arrives at the target. For reactions studied at the authors' laboratory, with their flight paths, this time is on the order of 400 ns

Defect trapping of deuterium implanted in aluminium

International Nuclear Information System (INIS)

Kido, Y.; Kakeno, M.; Yamada, K.; Hioki, T.; Kawamoto, J.

1982-01-01

The behaviour of deuterium implanted in Al was studied by the D( 3 He,p) 4 He and the D(d,p)T nuclear reactions. Changes of the depth profiles of the deuterium after heat treatments indicated that the implanted deuterium was trapped by the defect produced during the deuterium implantation and the release probability of the trapped deuterium increased as the specimen temperature was raised. Assuming a thermal equilibrium locally in the region of high defect concentration, the trapping energy of deuterium in Al was determined to be 0.12eV. Since the release probability for the single crystal was considerably larger than that for the polycrystal specimens, the deuterium was considered to be strongly trapped in the grain boundaries. Distributions of displaced Al atoms and the recovery of the lattice damage by annealing were measured by the channelling technique. (author)

Implementation of the Polarized HD target at the Thomas Jefferson National Accelerator Facility

International Nuclear Information System (INIS)

Chaden Djalali; David Tedeschi

2007-01-01

The original goal of this proposal was to study frozen spin polarized targets (HD target and other technologies) and produce a conceptual design report for the implementation of such a target in the HALL B detector of the Thomas Jefferson National Accelerator Facility (JLab). During the first two years of the proposal, we came to the conclusion that the best suited target for JLab was a frozen spin target and helped with the design of such a target. We have not only achieved our original goal but have exceeded it by being involved in the actual building and testing of parts the target. The main reason for this success has been the hiring of a senior research associate, Dr. Oleksandr Dzyubak, who had more than 10 years of experience in the field of frozen spin polarized targets. The current grant has allowed the USC nuclear physics group to strengthen its role in the JLab collaboration and make important contribution to both the detector development and the scientific program

Codeposition of deuterium ions with beryllium oxide at elevated temperatures

CERN Document Server

Markin, A V; Gorodetsky, A E; Negodaev, M A; Rozhanskii, N V; Scaffidi-Argentina, F; Werle, H; Wu, C H; Zalavutdinov, R K; Zakharov, A P

2000-01-01

Deuterium-loaded BeO films were produced by sputtering the beryllium target with 10 keV Ne ions in D sub 2 gas at a pressure of approximately 1 Pa. The sputtered beryllium reacts - on the substrate surface - with the residual oxygen, thus forming a beryllium oxide layer. Biasing the substrate negatively with respect to the target provides the simultaneous bombardment of the growing film surface with D ions formed by Ne-D sub 2 collisions. Substrate potential governs the maximum energy of ions striking the growing film surface while its size governs the flux density. According to X-ray photoelectron spectroscopy (XPS), electron probe microanalysis (EPMA) and reflection high energy electron diffraction (RHEED) data, the beryllium is deposited in the form of polycrystalline hcp-BeO layers with negligible (about 1 at.%) carbon and neon retention. Thermal desorption spectroscopy (TDS) data shows a strong deuterium bonding, with a desorption peak at 950 K, in the films deposited at -50 and -400 V substrate potentia...

A high intensity Stern-Gerlach polarized hydrogen source for the Munich MP-Tandem laboratory using ECR ionization and charge exchange in cesium vapor

International Nuclear Information System (INIS)

Hertenberger, R.; Eisermann, Y.; Metz, A.; Schiemenz, P.; Graw, G.

2001-01-01

The 14 year old Lamb-Shift hydrogen source of the Munich Tandem laboratory is presently replaced by a newly developed Stern-Gerlach type atomic beam source (ABS) with electron-cyclotron-resonance (ECR) ionization and subsequent double charge exchange in a supersonic cesium vapor jet target. The atomic beam source provides an intensity of 6.4*10 16 atoms/sec of polarized hydrogen and of about 5*10 16 atoms/sec of polarized deuterium. Beam intensities larger than 100 μA were observed for positive H-vector + and D-vector + ion beams after ECR ionization and intensities larger than 10 μA for negative D-vector - ion beams in three magnetic substates

Weak-electromagnetic interference in polarized eD scattering

International Nuclear Information System (INIS)

Prescott, C.Y.

1992-09-01

Observation of parity non-conservation in deep-inelastic scattering of polarized electrons from deuterium was reported in an experiment at SLAC in 1978. The events at SLAC and elsewhere leading to the successful search for parity non-conservation in the electromagnetic processes are described

Investigation of processes due to deuterium pellets impinging on a rigid wall

International Nuclear Information System (INIS)

Thoener, M.

1982-04-01

Pellets accelerated with a centrifuge - for refuelling thermonuclear plasmas - ought not to be noticeably deformed, let alone destroyed. This happens if the relative velocity between the pellet and the rotor catching it is too high. This report describes an apparatus for determining the variation in shape of deuterium pellets as a function of the relative velocity. In this method the pellet, produced by extrusion, is electromagnetically accelerated by means of metal carriers from which they are separated and shot at a stationary, rigid wall. The impact of the pellet on the target is recorded in seven pictures by spark cinematography and the impact velocity is measured with light barriers. The critical impact velocity for cylindrical deuterium pellets is found to be 48 m/s. Up to this relative velocity deuterium pellets retain their shape, irrespective of the direction of incidence. (orig.)

Deuterium trapping in liquid lithium irradiated by deuterium plasma

International Nuclear Information System (INIS)

Pisarev, A.; Moshkunov, K.; Vizgalov, I.; Gasparyan, Yu.

2013-01-01

Liquid lithium was irradiated by deuterium plasma to a low fluence of 10 22 –10 23 D/m 2 , cooled down to room temperature, and then slowly heated. The temperature and release rate were measured during heating. Two plateaus on the temperature–time dependence were observed at 180 °C and 660 °C. The first one corresponds to melting of Li and the second one – either to melting or to decomposition of solid LiD. Features of deuterium release in TDS were interpreted in terms of decomposition of lithium deuterides formed during plasma irradiation

Deuterium ion irradiation damage and deuterium trapping mechanism in candidate stainless steel material (JPCA2) for fusion reactor

International Nuclear Information System (INIS)

Ashizuka, Norihiro; Kurita, Takaaki; Yoshida, Naoaki; Fujiwara, Tadashi; Muroga, Takeo

1987-01-01

An improved austenitic stainless steel (JPCA), a candidate material for fusion reactor, is irradiated at room temperature with deuterium ion beams. Desorption spectra of deuterium gas is measured at various increased temperatures and defects formed under irradiation are observed by transmission electron microscopy to determine the mechanism of the thermal release of deuteriums and the characteristics of irradiation-induced defects involved in the process. In the deuterium deportion spectra observed, five release stages are found to exist at 90 deg C, 160 deg C, 220 deg C, 300 deg C and 400 deg C, referred to as Stage I, II, III, IV and V, respectively. Stage I is interpreted as representing the release of deuteriums trapped in point defects (presumably vacancies) formed under irradiation. The energy of desorption from the trapping sites is estimated at 0.8 eV. Stage II is concluded to be associated with the release of deuteriums trapped in a certain kind of existing defects. Stage III involves the release of deuteriums that are trapped in dislocations, dislocation loops or dislocated portions of stacking fault tetrahedra. This release occurs significantly in processed materials and other materials irradiated with high energy ion beams that may cause cascade damage. Stage IV is interpreted in terms of thermal decomposition of small deuterium clusters. Stage V is associated with the decomposition of rather large deuterium clusters grown on the {111} plane. (Nogami, K.)

Method of producing deuterium-oxide-enriched water

International Nuclear Information System (INIS)

Mandel, H.

1976-01-01

A method and apparatus for producing deuterium-oxide-enriched water (e.g., as a source of deuterium-rich gas mixtures) are disclosed wherein the multiplicity of individual cooling cycles of a power plant are connected in replenishment cascade so that fresh feed water with a naturally occurring level of deuterium oxide is supplied to replace the vaporization losses, sludge losses and withdrawn portion of water in a first cooling cycle, the withdrawn water being fed as the feed water to the subsequent cooling cycle or stage and serving as the sole feed-water input to the latter. At the end of the replenishment-cascade system, the withdrawn water has a high concentration of deuterium oxide and may serve as a source of water for the production of heavy water or deuterium-enriched gas by conventional methods of removing deuterium oxide or deuterium from the deuterium-oxide-enriched water. Each cooling cycle may form part of a thermal or nuclear power plant in which a turbine is driven by part of the energy and air-cooling of the water takes place in the atmosphere, e.g., in a cooling tower

Method of deuterium isotope separation and enrichment

International Nuclear Information System (INIS)

Benson, S.W.

1979-01-01

A method is described for separating and enriching deuterium containing molecules comprising the steps of: providing a source of organic molecules containing a normal abundance of deuterium atoms, the organic molecules having a structural formula RX, in which R is an organic radical selected from ethyl, isopropyl, t-butyl and 3-cyclopentenyl, and in which X is selected from F, Cl, Br and OH, and wherein R represents 3-cyclopentenyl, X may additionally represent H; exposing the molecules to the radiation of at least one pulsed infrared laser source which has been specifically tuned and focussed to selectively decompose RX molecules containing deuterium to form an enriched olefin specie containing deuterium, and HX; and separating the deuterium enriched olefin specie from the undecomposed deuterium depleted RX molecules and HX. (author)

Effect of nonlinearity of spin interaction with electromagnetic resonance field on characteristics of polarized nuclear target

International Nuclear Information System (INIS)

Vertij, A.A.; Gavrilov, S.P.; Shestopalov, V.P.

1990-01-01

Interaction of incident nuclear particle beam with J = 1/2 (neutrons) spin and (J = 1/2) protons with the target substance is considered. It is shown that neutron polarization at the target exit and neutron transparency (G) of the target depend significantly on incident wave amplitude level and physical parameter values which characterize the target, such as target temperature, resonator mirror reflection factor, number of spins interacting with the field, etc. Under interaction of neutrons with a target resonator which features a high mirror reflection factor and low losses for absorption which is not related to magnetic dipole absorption, a bistable response of neutron polarization and G manifests itself. 1 ref

Thermal x-rays and deuterium production in stellar flares

International Nuclear Information System (INIS)

Colgate, S.A.

1977-01-01

The x-ray spectrum of flares is shown to be necessarily thermal up to greater than or equal to 200 keV because the self magnetic field of any electron stream required for a thick or thin target source is inconsistently large. The resulting flare model can then be related to stellar luminosity, convection and magnetic fields to result in a maximum possible γ-burst (Mullan, 1976) and continuous x-ray flux. One of the most striking isotopic anomalies observed is the extreme enrichment of Helium (3) in some solar flares and the mysterious depletion of deuterium. It is discussed how deuterium may be produced and emitted in the largest flares associated with γ-bursts but in amounts insufficient to support the tentative conclusion of Colemen and Worden

Detection-Discrimination Method for Multiple Repeater False Targets Based on Radar Polarization Echoes

Directory of Open Access Journals (Sweden)

Z. W. ZONG

2014-04-01

Full Text Available Multiple repeat false targets (RFTs, created by the digital radio frequency memory (DRFM system of jammer, are widely used in practical to effectively exhaust the limited tracking and discrimination resource of defence radar. In this paper, common characteristic of radar polarization echoes of multiple RFTs is used for target recognition. Based on the echoes from two receiving polarization channels, the instantaneous polarization radio (IPR is defined and its variance is derived by employing Taylor series expansion. A detection-discrimination method is designed based on probability grids. By using the data from microwave anechoic chamber, the detection threshold of the method is confirmed. Theoretical analysis and simulations indicate that the method is valid and feasible. Furthermore, the estimation performance of IPRs of RFTs due to the influence of signal noise ratio (SNR is also covered.

Polarized proton target-III. Operations manual, revision B

International Nuclear Information System (INIS)

Hill, D.; Moretti, A.; Onesto, F.; Rynes, P.

1978-01-01

The manual presented contains certain standard operating procedures for the vacuum, cryogenic, and electronic systems of PPT-III. In total, these systems comprise the following major divisions: (1) the target cryostat; (2) the 4 He pumping system; (3) the 3 He pumping system; (4) the remote monitors and controls; (5) the microwave system; (6) the magnet and power supply; (7) the computerized polarization monitor; (8) the 4 He liquefier and gas recovery system; and (9) miscellaneous auxiliary equipment

Catalyzed deuterium-deuterium and deuterium-tritium fusion blankets for high temperature process heat production

International Nuclear Information System (INIS)

Ragheb, M.M.H.; Salimi, B.

1982-01-01

Tritiumless blanket designs, associated with a catalyzed deuterium-deuterium (D-D) fusion cycle and using a single high temperature solid pebble or falling bed zone, for process heat production, are proposed. Neutronics and photonics calculations, using the Monte Carlo method, show that an about 90% heat deposition fraction is possible in the high temperature zone, compared to a 30 to 40% fraction if a deuterium-tritium (D-T) fusion cycle is used with separate breeding and heat deposition zones. Such a design is intended primarily for synthetic fuels manufacture through hydrogen production using high temperature water electrolysis. A system analysis involving plant energy balances and accounting for the different fusion energy partitions into neutrons and charged particles showed that plasma amplification factors in the range of 2 are needed. In terms of maximization of process heat and electricity production, and the maximization of the ratio of high temperature process heat to electricity, the catalyzed D-D system outperforms the D-T one by about 20%. The concept is thought competitive to the lithium boiler concept for such applications, with the added potential advantages of lower tritium inventories in the plasma, reduced lithium pumping (in the case of magnetic confinement) and safety problems, less radiation damage at the first wall, and minimized risks of radioactive product contamination by tritium

Deuterium/hydrogen isotope exchange on beryllium and beryllium nitride; Deuterium/Wasserstoff-Isotopenaustausch an Beryllium und Berylliumnitrid

Energy Technology Data Exchange (ETDEWEB)

Dollase, Petra; Eichler, Michael; Koeppen, Martin; Dittmar, Timo; Linsmeier, Christian [Forschungszentrum Juelich GmbH, Institut fuer Energie- und Klimaforschung - Plasmaphysik (Germany)

2016-07-01

In the fusion experiments JET and ITER, the first wall is made up of beryllium. The use of nitrogen is discussed for radiative cooling in the divertor. This can react with the surface of the first wall to form beryllium nitride (Be{sub 3}N{sub 2}). The hydrogen isotopes deuterium and tritium, which react in the fusion reaction to helium and a neutron, are used as fuel. Since the magnetic confinement of the plasma is not perfect, deuterium and tritium ions are also found on the beryllium wall and can accumulate there. This should be avoided due to the radioactivity of tritium. Therefore the isotope exchange with deuterium is investigated to regenerate the first wall. We investigate the isotopic exchange of deuterium and protium in order to have not to work with radioactive tritium. The ion bombardment is simulated with an ion source. With voltages up to a maximum of 5 kV, deuterium and protic hydrogen ions are implanted in polycrystalline Be and Be{sub 3}N{sub 2}. The samples are then analyzed in situ using X-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). Subsequently, samples prepared under the same conditions are characterized ex-situ by means of nuclear reaction analysis (NRA). [German] In den Fusionsexperimenten JET und ITER besteht die erste Wand im Hauptraum aus Beryllium (Be). Zur Strahlungskuehlung im Divertor wird der Einsatz von Stickstoff diskutiert. Dieser kann mit der Oberflaeche der ersten Wand zu Berylliumnitrid (Be{sub 3}N{sub 2}) reagieren. Als Brennstoff werden die Wasserstoffisotope Deuterium und Tritium eingesetzt, die in der Fusionsreaktion zu Helium und einem Neutron reagieren. Da der magnetische Einschluss des Plasmas nicht perfekt ist, treffen auch Deuterium- und Tritiumionen auf die Berylliumwand auf und koennen sich dort anreichern. Das soll aufgrund der Radioaktivitaet von Tritium unbedingt vermieden werden. Daher wird zur Regenerierung der ersten Wand der Isotopenaustausch mit Deuterium untersucht. Wir

Synthesis of deuterium-labeled fluphenazine.

Science.gov (United States)

Shetty, H U; Hawes, E M; Midha, K K

1984-01-01

The propylpiperazine side chain of fluphenazine has been labeled with two, four, and six deuterium atoms by lithium aluminum deuteride reduction of the appropriate ester or imide. The gamma-carbon of the propyl group was labeled with two deuterium atoms by reduction of 10- (2-methoxycarbonylethyl) -2-trifluoromethyl-10H-phenothiazine, while four deuterium atoms were incorporated into the piperazine ring by reduction of 10-[3-(3,5-dioxo-1-piperazinyl)propyl]-2-trifluoromethyl-10H-pheno thiazine. The latter reduction gave the d4-labeled N-deshydroxyethyl metabolite of fluphenazine.

Target and double spin asymmetries of deeply virtual π 0 production with a longitudinally polarized proton target and CLAS

Energy Technology Data Exchange (ETDEWEB)

Kim, A.; Avakian, H.; Burkert, V.; Joo, K.; Kim, W.; Adhikari, K. P.; Akbar, Z.; Anefalos Pereira, S.; Badui, R. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Boiarinov, S.; Bosted, P.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Cao, T.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Chetry, T.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crede, V.; D' Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Djalali, C.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Eugenio, P.; Fedotov, G.; Fersch, R.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garc con, M.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Hanretty, C.; Hattawy, M.; Heddle, D.; Hicks, K.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joosten, S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Lanza, L.; Lenisa, P.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mattione, P.; McCracken, M. E.; McKinnon, B.; Mokeev, V.; Movsisyan, A.; Munevar, E.; Nadel-Turonski, P.; Net, L. A.; Niccolai, S.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Park, K.; Pasyuk, E.; Phelps, W.; Pisano, S.; Pogorelko, O.; Price, J. W.; Prok, Y.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Salgado, C.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, G. D.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Torayev, B.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Zachariou, N.; Zana, L.; Zhang, J.

2017-05-01

The target and double spin asymmetries of the exclusive pseudoscalar channel e→p→→epπ0 were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of Q2, xB, -t and Φ. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs H˜T and ET, and complement previous measurements of unpolarized structure functions sensitive to the GPDs HT and E¯T. These data provide a crucial input for parametrizations of essentially unknown chiral-odd GPDs and will strongly influence existing theoretical calculations based on the handbag formalism.

Polarization of lanthanum nucleus by dynamic polarization method

International Nuclear Information System (INIS)

Adachi, Toshikazu; Ishimoto, Shigeru; Masuda, Yasuhiro; Morimoto, Kimio

1989-01-01

Preliminary studies have been carried out concerning the application of a dynamic polarization method to polarizing lanthanum fluoride single crystal to be employed as target in experiments with time reversal invariance. The present report briefly outlines the dynamic polarization method and describes some preliminary studies carried out so far. Dynamic polarization is of particular importance because no techniques are currently available that can produce highly polarized static nucleus. Spin interaction between electrons and protons (nuclei) plays a major role in the dynamic polarization method. In a thermal equilibrium state, electrons are polarized almost completely while most protons are not polarized. Positively polarized proton spin is produced by applying microwave to this system. The most hopeful candidate target material is single crystal of LaF 3 containing neodymium because the crystal is chemically stable and easy to handle. The spin direction is of great importance in experiments with time reversal invariance. The spin of neutrons in the target can be cancelled by adjusting the external magnetic field applied to a frozen polarized target. In a frozen spin state, the polarity decreases slowly with a relaxation time that depends on the external magnetic field and temperature. (N.K.)

Few-body experiments with polarized beams and polarized targets

International Nuclear Information System (INIS)

Simmons, J.E.

1983-01-01

A survey is presented concerning recent polarization experiments in the elastic p-d, p- 3 He, and p- 4 He systems. Mention is made of selected neutron experiments. The nominal energy range is 10 to 1000 MeV. Recent results and interpretations of the p-d system near 10 MeV are discussed. New experiments on the energy dependence of back angle p-d tensor polarization are discussed with respect to resolution of discrepancies and difficulty of theoretical interpretation. Progress is noted concerning multiple scattering interpretation of forward p-d deuteron polarization. Some new results are presented concerning the p- 3 He system and higher energy p- 4 He polarization experiments. 52 references

Method of deuterium isotope separation and enrichment

International Nuclear Information System (INIS)

Benson, S.W.

1980-01-01

A method of deuterium isotope separation and enrichment using infrared laser technology in combination with chemical processes for treating and recycling the unreacted and deuterium-depleted starting materials is described. Organic molecules of the formula RX (where R is an ethyl, isopropyl, t-butyl, or cyclopentenyl group and X is F, Cl, Br or OH) containing a normal abundance of hydrogen and deuterium are exposed to intense laser infrared radiation. An olefin containing deuterium (olefin D) will be formed, along with HX. The enriched olefin D can be stripped from the depleted stream of RX and HX, and can be burned to form enriched water or pyrolyzed to produce hydrogen gas with elevated deuterium content. The depleted RX is decomposed to olefins and RX, catalytically exchanged with normal water to restore the deuterium content to natural levels, and recombined to form RX which can be recycled. (LL)

Setup and proof of principle of SAPIS (Stored Atoms Polarized Ion Source), a novel source of polarized H-/D- ions

International Nuclear Information System (INIS)

Emmerich, R.

2007-01-01

The objective of this work was the setup and the proof-of-principle of a new type of negative polarized hydrogen or deuterium ion source, which is based on the charge-exchange reaction vectorH 0 +Cs 0 →vectorH - +Cs + , as for instance the Colliding-Beams-Source (CBS) at the Cooler Synchrotron COSY in Juelich. In contrast to the CBS, the use of a storage cell for the charge-exchange region promises an increase in H - current by at least an order of magnitude without considerable polarization losses. For these purposes, a new laboratory was equipped and both a polarized hydrogen/deuterium atomic beam source and an intense neutral cesium-beam source have been build-on. A Lambshift polarimeter, which allows the measurement of the nuclear polarization of the atomic as well as ionic beams, was completed with the construction of a new spin-filter. After commissioning and optimizing each of these sources, a storage cell was developed and installed in the charge-exchange region with a magnetic field. Additionally, components for the extraction, detection and analysis of the negative ion beam were installed. Following the decisive proof of principle, investigation of the properties of the storage cell, especially as to H recombination and depolarisation, was begun. Furthermore, a number of software programs was developed for the control and monitoring of different components of the sources as well as a universal measuring software for the complete installation, including the measurement and calculation of the beam polarization. At the same time, the remote control system of the Cologne source of polarized ions LASCO at the FN tandem accelerator was completely modernized. (orig.)

Magnetic shielding for a transversely polarized target in the longitudinal field of the PANDA solenoid

Energy Technology Data Exchange (ETDEWEB)

Froehlich, Bertold; Ahmed, Samer; Dbeyssi, Alaa; Mora Espi, Maria Carmen; Gerz, Kathrin; Lin, Dexu; Maas, Frank; Martinez, Ana Penuelas; Morales, Cristina; Wang, Yadi [Helmholtz Institut Mainz (Germany); Aguar Bartolome, Patricia [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet Mainz (Germany)

2016-07-01

A transversely polarized target in PANDA would allow for the first time access to the imaginary part of the time like electromagnetic proton form factors, namely the phase angle in the imaginary plane between electric and magnetic form factors. Moreover it would allow for a number of other target single spin asymmetries revealing nucleon structure observables connected with the transverse spin structure of the proton. As a first step for achieving a transverse target polarization, the target region has to be shielded against the 2 T longitudinal magnetic flux from the solenoid of the PANDA spectrometer. We present experimental results on intense magnetic flux shielding using a BSCCO-2212 high temperature superconducting hollow cylinder at liquid helium temperature.

Moeller polarimeter for VEPP-3 storage ring based on internal polarized gas jet target

International Nuclear Information System (INIS)

Dyug, M.V.; Grigoriev, A.V.; Kiselev, V.A.; Lazarenko, B.A.; Levichev, E.B.; Mikaiylov, A.I.; Mishnev, S.I.; Nikitin, S.A.; Nikolenko, D.M.; Rachek, I.A.; Shestakov, Yu.V.; Toporkov, D.K.; Zevakov, S.A.; Zhilich, V.N.

2005-01-01

A new method to determine the polarization of an electron beam circulating in a storage ring by a non-destructive way, based on measuring the asymmetry in scattering of beam electrons on electrons of the internal polarized gas jet target, has been developed and tested at the VEPP-3 storage ring

Laser polarization dependence of proton emission from a thin foil target irradiated by a 70 fs, intense laser pulse

International Nuclear Information System (INIS)

Fukumi, A.; Nishiuchi, M.; Daido, H.; Li, Z.; Sagisaka, A.; Ogura, K.; Orimo, S.; Kado, M.; Hayashi, Y.; Mori, M.; Bulanov, S.V.; Esirkepov, T.; Nemoto, K.; Oishi, Y.; Nayuki, T.; Fujii, T.; Noda, A.; Nakamura, S.

2005-01-01

A study of proton emission from a 3-μm-thick Ta foil target irradiated by p-, s-, and circularly polarized laser pulses with respect to the target plane has been carried out. Protons with energies up to 880 keV were observed in the target normal direction under the irradiation by the p-polarized laser pulse, which yielded the highest efficiency for proton emission. In contrast, s- and circularly polarized laser pulses gave the maximum energies of 610 and 680 keV, respectively. The difference in the maximum energy between the p- and s-polarized cases was associated with the difference between the sheath fields estimated from electron spectra

Optically pumped polarized alkali atomic beams and targets

International Nuclear Information System (INIS)

Anderson, L.W.

1984-01-01

The optical pumping of 23 Na and 6 Li atomic beams is discussed. Experiments on the optical pumping of 23 Na atomic beams using either a single mode dye laser followed by a double passed acousto-optic modulator or a multimode dye laser are reported. The optical pumping of a 23 Na vapor target for use in a polarized H - ion source is discussed. Results on the use of viton as a wall coating with a long relaxation time are reported. 31 references, 6 figures, 3 tables

Point design for deuterium-deuterium compact reversed-field pinch reactors

International Nuclear Information System (INIS)

Dabiri, A.E.; Dobrott, D.R.; Gurol, H.; Schnack, D.D.

1984-01-01

A deuterium-deuterium (D-D) reversed-field pinch (RFP) reactor may be made comparable in size and cost to a deuterium-tritium (D-T) reactor at the expense of high-thermal heat load to the first wall. This heat load is the result of the larger percentage of fusion power in charged particles in the D-D reaction as compared to the D-T reaction. The heat load may be reduced by increasing the reactor size and hence the cost. In addition to this ''degraded'' design, the size may be kept small by means of a higher heat load wall, or by means of a toroidal divertor, in which case most of the heat load seen by the wall is in the form of radiation. Point designs are developed for these approaches and cost studies are performed and compared with a D-T reactor. The results indicate that the cost of electricity of a D-D RFP reactor is about20% higher than a D-T RFP reactor. This increased cost could be offset by the inherent safety features of the D-D fuel cycle

Recent progress in the development of a polarized proton target for reactions with radioactive ion beams

International Nuclear Information System (INIS)

Urrego-Blanco, J.P.; Bingham, C.R.; Brandt, B. van den; Galindo-Uribarri, A.; Gomez del Campo, J.; Hautle, P.; Konter, J.A.; Padilla-Rodal, E.; Schmelzbach, P.A.

2007-01-01

Polarization observables in nuclear reactions with stable beams have provided important information concerning structural properties of nuclei and reaction mechanisms and hold great promise in the context of exotic nuclei. We report on the development of a polarized target based on plastic foils of 20-200 μm thickness to be used with radioactive ion beams. The operation of such a target requires a moderately high magnetic field and very low temperatures. The plastic foil is placed inside a chamber attached to the mixing chamber of a 3 He- 4 He dilution refrigerator. Cooling of the foil is achieved via a superfluid film of 4 He that can be supplied through two capillaries. The chamber has two thin, highly uniform silicon nitride windows. An NMR coil is attached to the target to monitor the polarization. Results of a first test to characterize the target system, using the elastic scattering of 38 MeV 12 C by protons in inverse kinematics are presented

Distribution of deuterium and hydrogen in Zr and Ti foil assemblies under the action of a pulsed deuterium high-temperature plasma

Science.gov (United States)

Bondarenko, G. G.; Volobuev, I. V.; Eriskin, A. A.; Kobzev, A. P.; Nikulin, V. Ya.; Peregudova, E. N.; Silin, P. V.; Borovitskaya, I. V.

2017-09-01

Deuteron and proton elastic recoil detection analysis is used to study the accumulation and redistribution of deuterium and hydrogen in assemblies of two high-pure zirconium or titanium foils upon pulsed action of high-temperature deuterium plasma (PHTDP) in a plasma-focus installation PF-4. It is noted that, under the action of PHTDP, an implanted deuterium and hydrogen gas impurity are redistributed in the irradiated foils in large depths, which are significantly larger than the deuterium ion free paths (at their maximum velocity to 108 cm/s). The observed phenomenon is attributed to the carrying out of implanted deuterium and hydrogen under the action of powerful shock waves formed in the metallic foils under the action of PHTDP and/or the acceleration of diffusion of deuterium and hydrogen atoms under the action of a compression-rarefaction shock wave at the shock wave front with the redistribution of deuterium and hydrogen to large depths.

Erosion and deuterium retention of CLF-1 steel exposed to deuterium plasma

Science.gov (United States)

Qiao, L.; Wang, P.; Hu, M.; Gao, L.; Jacob, W.; Fu, E. G.; Luo, G. N.

2017-12-01

In recent years reduced activation ferritic martensitic steel has been proposed as the plasma-facing material in remote regions of the first wall. This study reports the erosion and deuterium retention behaviours in CLF-1 steel exposed to deuterium (D) plasma in a linear experimental plasma system as function of incident ion energy and fluence. The incident D ion energy ranges from 30 to 180 eV at a flux of 4 × 1021 D m-2 s-1 up to a fluence of 1025 D m-2. SEM images revealed a clear change of the surface morphology as functions of incident fluence and impinging energy. The mass loss results showed a decrease of the total sputtering yield of CLF-1 steel with increasing incident fluence by up to one order of magnitude. The total sputtering yield of CLF-1 steel after 7.2 × 1024 D m-2 deuterium plasma exposure reduced by a factor of 4 compared with that of pure iron, which can be attributed to the enrichment of W at the surface due to preferential sputtering of iron and chromium. After D plasma exposure, the total deuterium retention in CLF-1 steel samples measured by TDS decreased with increasing incident fluence and energy, and a clear saturation tendency as function of incident fluence or energy was also observed.

The deuterium inventory in ASDEX Upgrade

International Nuclear Information System (INIS)

Mayer, M.; Rohde, V.; Ramos, G; Vainonen-Ahlgren, E.; Likonen, J.; Herrmann, A.; Neu, R.

2007-01-01

The deuterium inventory in ASDEX Upgrade was determined by quantitative ion beam analysis techniques and SIMS for different discharge campaigns between the years 2002 and 2005. ASDEX Upgrade was a carbon dominated machine during this phase. Full poloidal sections of the lower and upper divertor tile surfaces, limiter tiles, gaps between divertor tiles, gaps between inner heat shield tiles and samples from remote areas below the roof baffle and in pump ducts were analysed, thus offering an exhaustive survey of all relevant areas in ASDEX Upgrade. Deuterium is mainly trapped on plasma-exposed surfaces of inner divertor tiles, where about 70% of the retained deuterium inventory is found. About 20% of the inventory is retained at or below the divertor roof baffle, and about 10% is observed in other areas, such as the outer divertor and in gaps between tiles. The long term deuterium retention is 3-4% of the total deuterium input. The obtained results are compared with gas balance measurements, and conclusions about tritium retention in ITER are made

Spherical cauliflower-like carbon dust formed by interaction between deuterium plasma and graphite target and its internal structure

Energy Technology Data Exchange (ETDEWEB)

Ohno, N. [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)], E-mail: ohno@ees.nagoya-u.ac.jp; Yoshimi, M. [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Tokitani, M. [National Institute for Fusion Science, Oroshi 322-6, Toki 509-5292 (Japan); Takamura, S. [Department of Electronics, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Tokunaga, K.; Yoshida, N. [Research Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

2009-06-15

Simulated experiments to produce carbon dust particles with cauliflower structure have been performed in a liner plasma device, NAGDIS-II by exposing high density deuterium plasma to a graphite sample (IG-430U). Formation of carbon dust depends on the surface temperature and the incident ion energy. At a surface temperature 600-700 K, a lot of isolated spherical dust particles are observed on the graphite target. The internal structure of an isolated dust particle was observed with Focused Ion Beam (FIB) system and Transmission Electron Microscope (TEM) in detail. FIB analysis clearly shows there exist honey-combed cell structure with thin carbon walls in the dust particle and the dust particle grows from the graphite surface. TEM image also shows that the dust particle is made of amorphous carbon with crystallized grains with diameters of 10-50 nm.

Target and double spin asymmetries of deeply virtual π0 production with a longitudinally polarized proton target and CLAS

Directory of Open Access Journals (Sweden)

A. Kim

2017-05-01

Full Text Available The target and double spin asymmetries of the exclusive pseudoscalar channel e→p→→epπ0 were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS. The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of Q2, xB, −t and ϕ. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs provides the first insight on the chiral-odd GPDs H˜T and ET, and complement previous measurements of unpolarized structure functions sensitive to the GPDs HT and E¯T. These data provide a crucial input for parametrizations of essentially unknown chiral-odd GPDs and will strongly influence existing theoretical calculations based on the handbag formalism.

Target and double spin asymmetries of deeply virtual π0 production with a longitudinally polarized proton target and CLAS

Science.gov (United States)

Kim, A.; Avakian, H.; Burkert, V.; Joo, K.; Kim, W.; Adhikari, K. P.; Akbar, Z.; Anefalos Pereira, S.; Badui, R. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Boiarinov, S.; Bosted, P.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Cao, T.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Chetry, T.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Djalali, C.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Eugenio, P.; Fedotov, G.; Fersch, R.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garc con, M.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Hanretty, C.; Hattawy, M.; Heddle, D.; Hicks, K.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joosten, S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Lanza, L.; Lenisa, P.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mattione, P.; McCracken, M. E.; McKinnon, B.; Mokeev, V.; Movsisyan, A.; Munevar, E.; Nadel-Turonski, P.; Net, L. A.; Niccolai, S.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Park, K.; Pasyuk, E.; Phelps, W.; Pisano, S.; Pogorelko, O.; Price, J. W.; Prok, Y.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Salgado, C.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, G. D.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Torayev, B.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Zachariou, N.; Zana, L.; Zhang, J.

2017-05-01

The target and double spin asymmetries of the exclusive pseudoscalar channel e → p → → epπ0 were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of Q2, xB, -t and ϕ. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs H˜T and ET, and complement previous measurements of unpolarized structure functions sensitive to the GPDs HT and EbarT. These data provide a crucial input for parametrizations of essentially unknown chiral-odd GPDs and will strongly influence existing theoretical calculations based on the handbag formalism.

Desorption dynamics of deuterium molecules from the Si(100)-(3x1) dideuteride surface.

Science.gov (United States)

Niida, T; Tsurumaki, H; Namiki, A

2006-01-14

We measured polar angle (theta)-resolved time-of-flight spectra of D2 molecules desorbing from the Si(100)-(3x1) dideuteride surface. The desorbing D2 molecules exhibit a considerable translational heating with mean desorption kinetic energies of approximately 0.25 eV, which is mostly independent of the desorption angles for 0 degreesdynamics of deuterium was discussed along the principle of detailed balance to predict their adsorption dynamics onto the monohydride Si surface.

Energetics of semi-catalyzed-deuterium, light-water-moderated, fusion-fission toroidal reactors

International Nuclear Information System (INIS)

Jassby, D.L.; Towner, H.H.; Greenspan, E.; Schneider, A.; Misolovin, A.; Gilai, D.

1978-07-01

The semi-catalyzed-deuterium Light-Water Hybrid Reactor (LWHR) comprises a lithium-free light-water-moderated blanket with U 3 Si fuel driven by a deuterium-based fusion-neutron source, with complete burn-up of the tritium but almost no burn-up of the helium-3 reaction product. A one-dimensional model for a neutral-beam-driven tokamak plasma is used to determine the operating modes under which the fusion energy multiplication Q/sub p/ can be equal to or greater than 0.5. Thermonuclear, beam-target, and energetic-ion reactions are taken into account. The most feasible operating conditions for Q/sub p/ approximately 0.5 are tau/sub E/ = 2 to 4 x 10 14 cm -3 s, = 10 to 20 keV, and E/sub beam/ = 500 to 1000 keV, with approximately 40% of the fusion energy produced by beam-target reactions. Illustrative parameters of LWHRs are compared with those of an ignited D-T reactor

The Geissen polarization facility. I

International Nuclear Information System (INIS)

Arnold, W.; Berg, H.; Krause, H.H.; Ulbricht, J.; Clausnitzer, G.

1977-01-01

A source for the production of polarized negative hydrogen or deuterium ions following the Lambshift method is described. A duoplasmatron with expansion cup and extended ion optics is used. The polarization is generated by a diabetic zero field passage of the metastable atoms. For precision experiments the polarization can be switched 'on' and 'off' with a frequency of 1 kHz by a disturbance with a transverse magnetic field. The quantization axis can be rotated with a Wien filter. All source components are installed in a compact vacuum chamber, which allows high effective pumping speeds. The overal length of the source including the Wien filter is 1.7m. With a 10mm diameter cesium canal typical H - currents of 0.6-0.75 μA (P=0.7-0.75) and maximum currents of 0.9μA are obtained. (Auth.)

Luminance and chromatic contributions to a hyperacuity task: isolation by contrast polarity and target separation.

Science.gov (United States)

Sun, Hao; Cooper, Bonnie; Lee, Barry B

2012-03-01

Vernier thresholds are known to be elevated when a target pair has opposite contrast polarity. Polarity reversal is used to assess the role of luminance and chromatic pathways in hyperacuity performance. Psychophysical hyperacuity thresholds were measured for pairs of gratings of various combinations of luminance (Lum) and chromatic (Chr) contrast polarities, at different ratios of luminance to chromatic contrast. With two red-green gratings of matched luminance and chromatic polarity (+Lum+Chr), there was an elevation of threshold at isoluminance. When both luminance and chromatic polarity were mismatched (-Lum-Chr), thresholds were substantially elevated under all conditions. With the same luminance contrast polarity and opposite chromatic polarity (+Lum-Chr) thresholds were only elevated close to isoluminance; in the reverse condition (-Lum+Chr), thresholds were elevated as in the -Lum-Chr condition except close to equiluminance. Similar data were obtained for gratings isolating the short-wavelength cone mechanism. Further psychophysical measurements assessed the role of target separation with matched or mismatched contrast polarity; similar results were found for luminance and chromatic gratings. Comparison physiological data were collected from parafoveal ganglion cells of the macaque retina. Positional precision of ganglion cell signals was assessed under conditions related to the psychophysical measurements. On the basis of these combined observations, it is argued that both magnocellular, parvocellular, and koniocellular pathways have access to cortical positional mechanisms associated with vernier acuity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Deuterium trapping in tungsten

Science.gov (United States)

Poon, Michael

Tungsten is one of the primary material candidates being investigated for use in the first-wall of a magnetic confinement fusion reactor. An ion accelerator was used to simulate the type of ion interaction that may occur at a plasma-facing material. Thermal desorption spectroscopy (TDS) was the primary tool used to analyze the effects of the irradiation. Secondary ion mass spectroscopy (SIMS) was used to determine the distribution of trapped D in the tungsten specimen. The tritium migration analysis program (TMAP) was used to simulate thermal desorption profiles from the D depth distributions. Fitting of the simulated thermal desorption profiles with the measured TDS results provided values of the D trap energies. Deuterium trapping in single crystal tungsten was studied as a function of the incident ion fluence, ion flux, irradiation temperature, irradiation history, and surface impurity levels during irradiation. The results show that deuterium was trapped at vacancies and voids. Two deuterium atoms could be trapped at a tungsten vacancy, with trapping energies of 1.4 eV and 1.2 eV for the first and second D atoms, respectively. In a tungsten void, D is trapped as atoms adsorbed on the inner walls of the void with a trap energy of 2.1 eV, or as D2 molecules inside the void with a trap energy of 1.2 eV. Deuterium trapping in polycrystalline tungsten was also studied as a function of the incident fluence, irradiation temperature, and irradiation history. Deuterium trapping in polycrystalline tungsten also occurs primarily at vacancies and voids with the same trap energies as in single crystal tungsten; however, the presence of grain boundaries promotes the formation of large surface blisters with high fluence irradiations at 500 K. In general, D trapping is greater in polycrystalline tungsten than in single crystal tungsten. To simulate mixed materials comprising of carbon (C) and tungsten, tungsten specimens were pre-irradiated with carbon ions prior to D

Deuterium trapping in tungsten

International Nuclear Information System (INIS)

Poon, M.

2004-01-01

Tungsten is one of the primary material candidates being investigated for use in the first-wall of a magnetic confinement fusion reactor. An ion accelerator was used to simulate the type of ion interaction that may occur at a plasma-facing material. Thermal desorption spectroscopy (TDS) was the primary tool used to analyze the effects of the irradiation Secondary ion mass spectroscopy (SIMS) was used to determine the distribution of trapped D in the tungsten specimen. The tritium migration analysis program (TMAP) was used to simulate thermal desorption profiles from the D depth distributions. Fitting of the simulated thermal desorption profiles with the measured TDS results provided values of the D trap energies. . Deuterium trapping in single crystal tungsten was studied as a function of the incident ion fluence, ion flux, irradiation temperature, irradiation history, and surface impurity levels during irradiation The results show that deuterium was trapped at vacancies and voids. Two deuterium atoms could be trapped at a tungsten vacancy, with trapping energies of 1.4 eV and 1.2 eV for the first and second D atoms, respectively. In a tungsten void, D is trapped as atoms adsorbed on the inner walls of the void with a trap energy of 2.1 eV, or as D 2 molecules inside the void with a trap energy of 1.2 eV. . Deuterium trapping in polycrystalline tungsten was also studied as a function of the incident fluence, irradiation temperature, and irradiation history. Deuterium trapping in polycrystalline tungsten also occurs primarily at vacancies and voids with the same trap energies as in single crystal tungsten; however, the presence of grain boundaries promotes the formation of large surface blisters with high fluence irradiations at 500 K. In general, D trapping is greater in polycrystalline tungsten than in single crystal tungsten. To simulate mixed materials comprising of carbon (C) and tungsten, tungsten specimens were pre-irradiated with carbon ions prior to D

Deuterium trapping in tungsten

Energy Technology Data Exchange (ETDEWEB)

Poon, M

2004-07-01

Tungsten is one of the primary material candidates being investigated for use in the first-wall of a magnetic confinement fusion reactor. An ion accelerator was used to simulate the type of ion interaction that may occur at a plasma-facing material. Thermal desorption spectroscopy (TDS) was the primary tool used to analyze the effects of the irradiation Secondary ion mass spectroscopy (SIMS) was used to determine the distribution of trapped D in the tungsten specimen. The tritium migration analysis program (TMAP) was used to simulate thermal desorption profiles from the D depth distributions. Fitting of the simulated thermal desorption profiles with the measured TDS results provided values of the D trap energies. . Deuterium trapping in single crystal tungsten was studied as a function of the incident ion fluence, ion flux, irradiation temperature, irradiation history, and surface impurity levels during irradiation The results show that deuterium was trapped at vacancies and voids. Two deuterium atoms could be trapped at a tungsten vacancy, with trapping energies of 1.4 eV and 1.2 eV for the first and second D atoms, respectively. In a tungsten void, D is trapped as atoms adsorbed on the inner walls of the void with a trap energy of 2.1 eV, or as D{sub 2} molecules inside the void with a trap energy of 1.2 eV. . Deuterium trapping in polycrystalline tungsten was also studied as a function of the incident fluence, irradiation temperature, and irradiation history. Deuterium trapping in polycrystalline tungsten also occurs primarily at vacancies and voids with the same trap energies as in single crystal tungsten; however, the presence of grain boundaries promotes the formation of large surface blisters with high fluence irradiations at 500 K. In general, D trapping is greater in polycrystalline tungsten than in single crystal tungsten. To simulate mixed materials comprising of carbon (C) and tungsten, tungsten specimens were pre-irradiated with carbon ions prior to D

Solid deuterium centrifuge pellet injector

International Nuclear Information System (INIS)

Foster, C.A.

1982-01-01

Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150 0 of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength KEVLAR/epoxy composite. This arbon has been spin-tested to a tip speed of 1 km/s

Solid deuterium centrifuge pellet injector

International Nuclear Information System (INIS)

Foster, C.A.

1983-01-01

Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150 0 of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength Kevlar/epoxy composite. This arbor has been spin-tested to a tip speed of 1 km/s

Measurement of scattering cross sections of liquid and solid hydrogen, deuterium and deuterium hydride for thermal neutrons

International Nuclear Information System (INIS)

Seiffert, W.D.

1984-01-01

The scattering cross sections for liquid and solid normal hydrogen, para-hydrogen, deuterium and deuterium hydride were measured for thermal neutrons at various temperatures. Solid samples of para-hydrogen exhibit distinct Bragg scattering. Liquid samples of deuterium and para-hydrogen also exhibit distinct coherence phenomena, which is indicative of strong local ordering of the molecules. In para-hydrogen and deuterium hydride, the threshold for scattering with excitation of rotations is distinctly visible. The positions of the thresholds show that the molecules in liquid hydrogen are not unhindered in their movement. After the beginning of the rotational excitation the scattering cross sections of liquid and solid para-hydrogen have different shapes which is to be explained by the differences in the dynamics of the liquid and the solid specimen. 22 references

Retention and features of deuterium detrapping from radiation-induced damages in steels

International Nuclear Information System (INIS)

Tolstolutskaya, G.D.; Ruzhytskiy, V.V.; Karpov, S.A.; Kopanets, I.E.

2009-01-01

The accelerators and ion-beam analysis techniques are used for simulation of displacement damage and detailed investigation of distribution profiles of damage and impurity gas atoms (especially helium and hydrogen) in the irradiation of targets for a wide ranges of doses and particle energies. The influence of preimplanted helium and heavy ion-induced damage on deuterium trapping in austenitic and ferritic/martensitic steels was studied. The results obtained for 18Cr10NiTi stainless steel show that ion-implanted deuterium is weakly trapped by defects produced in 5 keV D + displacement cascades. The effective trapping temperature interval is between 300 and 600 K. The characteristics of trapping and the temperature range of hydrogen isotopes retention in traps formed by prior implantation of helium depend on the concentration of implanted helium and on the type of defects developed. The formation of helium bubbles in 18Cr10NiTi steel causes an order of magnitude increase in the content of retained deuterium atoms in the range of temperature 300-600 K and extends the interval of effective trapping temperatures to 1000 K. Energetic heavy-ion irradiation (1.4 MeV Ar + ) has been used for modeling defect cluster formation under displacement cascade conditions to simulate fusion reactor environments. It was found that retention of hydrogen and deuterium strongly increased in this case. It is shown that the presence of a surface-passive film considerably shifts the gas release interval to higher temperatures and reduces the deuterium surface recombination coefficient by several orders of magnitude.

Near infrared spectral polarization imaging of prostate cancer tissues using Cybesin: a receptor-targeted contrast agent

Science.gov (United States)

Pu, Yang; Wang, W. B.; Tang, G. C.; Liang, Kexian; Achilefu, S.; Alfano, R. R.

2013-03-01

Cybesin, a smart contrast agent to target cancer cells, was investigated using a near infrared (NIR) spectral polarization imaging technique for prostate cancer detection. The approach relies on applying a contrast agent that can target cancer cells. Cybesin, as a small ICG-derivative dye-peptide, emit fluorescence between 750 nm and 900 nm, which is in the "tissue optical window". Cybesin was reported targeting the over-expressed bombesin receptors in cancer cells in animal model and the human prostate cancers over-expressing bombesin receptors. The NIR spectral polarization imaging study reported here demonstrated that Cybesin can be used as a smart optical biomarker and as a prostate cancer receptor targeted contrast agent.

Effect of H-wave polarization on laser radar detection of partially convex targets in random media.

Science.gov (United States)

El-Ocla, Hosam

2010-07-01

A study on the performance of laser radar cross section (LRCS) of conducting targets with large sizes is investigated numerically in free space and random media. The LRCS is calculated using a boundary value method with beam wave incidence and H-wave polarization. Considered are those elements that contribute to the LRCS problem including random medium strength, target configuration, and beam width. The effect of the creeping waves, stimulated by H-polarization, on the LRCS behavior is manifested. Targets taking large sizes of up to five wavelengths are sufficiently larger than the beam width and are sufficient for considering fairly complex targets. Scatterers are assumed to have analytical partially convex contours with inflection points.

Computer control of the SMC polarized target

International Nuclear Information System (INIS)

Le Goff, J.M.; Azoulay, R.; Berglund, P.; Dulya, C.; Gournay, J.F.; Hayashi, N.; Kyynaeraeinen, J.; Magnon, A.; Niinikoski, T.O.; Trentalange, S.

1995-01-01

The SMC polarized target is controlled through VME crates driven by CPUs working under the VxWorks operating system. The CPUs are connected to a SUN workstation which provides the user interface due to a graphical package named SL-GMS. This results in user friendliness, high modularity and flexibility. The system allows the control of: (1) the superconductive solenoid and the transverse dipole: control of the power supplies; automatic reversal of the spin direction by field rotation; acquisition, display and storage of the electric and cryogenic parameters; generation of alarms; and (2) the dilution refrigerator: evaporator level control; acquisition, display and storage of ∼100 cryogenic parameters; and generation of alarms. ((orig.))

Method for measuring deuterium in erbium deuteride films

International Nuclear Information System (INIS)

Brangan, J.R.; Thornberg, S.M.; Keenan, M.R.

1997-09-01

Determining the quantity of deuterium in an erbium deuteride (ErD 2 ) film is essential for assessing the quality of the hydriding process but is a challenging measurement to make. First, the ideal gas law cannot be applied directly due to high temperature (950 degrees C) and low temperature (25 degrees C) regions in the same manifold. Additionally, the metal hydride does not release all of the deuterium rapidly upon heating and metal evaporation occurs during extended heating periods. Therefore, the method developed must provide a means to compensate for temperature inhomogeneities and the amount of deuterium retained in the metal film while heating for a minimal duration. This paper presents two thermal desorption methods used to evaluate the kinetics and equilibria of the deuterium desorption process at high temperatures (950 degrees C). Of primary concern is the evaluation of the quantity of deuterium remaining in these films at the high temperature. A multiple volume expansion technique provided insight into the kinetics of the deuterium evolution and metal evaporation from the film. Finally a repeated pump-down approach yielded data that indicated approximately 10% of the deuterium is retained in the metal film at 950 degrees C and approximately 1 Torr pressure. When the total moles of deuterium determined by this method were divided by the moles of erbium determined by ICP/AES, nearly stochiometric values of 2:1 were obtained for several erbium dideuteride films. Although this work presents data for erbium and deuterium, these methods are applicable to other metal hydrides as well

Counter-diffusion and -permeation of deuterium and hydrogen through metals

Energy Technology Data Exchange (ETDEWEB)

Kizu, Kaname; Tanabe,; Tetsuo, [Nagoya Univ. (Japan)

1998-03-01

The first experiments for counter-diffusion and -permeation of deuterium and hydrogen through palladium were performed. Deuterium permeation rates against D{sub 2} pressure were measured under the condition where hydrogen permeated to opposite direction by supplying H{sub 2} gas at the permeated side of D{sub 2}. It was found that not a small amount of deuterium was clearly permeated even if the deuterium pressure was much smaller than the hydrogen pressure. Deuterium permeation rate was gradually reduced by increasing the counter H permeation. The deuterium permeation rate under the counter H permeation is well represented by a simple model in which the ratio of the deuterium permeation rates with and without the counter H permeation was proportional to the fractional concentration of deuterium in the bulk. As increasing the hydrogen counter flow, however, the deuterium permeation rate deviates from the model. This means that adsorption (absorption) of D{sub 2} from gas phase is inhibited and surface recombination of deuterium is blocked by hydrogen. (author)

Desorption dynamics of deuterium molecules from the Si(100)-(3×1) dideuteride surface

OpenAIRE

Niida, T; Tsurumaki, Hiroshi; Namiki, Akira

2006-01-01

We measured polar angle ()-resolved time-of-flight spectra of D2 molecules desorbing from the Si(100)-(3×1) dideuteride surface. The desorbing D2 molecules exhibit a considerable translational heating with mean desorption kinetic energies of 0.25 eV, which is mostly independent of the desorption angles for 0°30°. The observed desorption dynamics of deuterium was discussed along the principle of detailed balance to predict their adsorption dynamics onto the monohydride Si surface.

Additive quark model and double scattering of pions and protons in deuterium

International Nuclear Information System (INIS)

Bialas, A.; Czyz, W.; Kisielewska, D.

1981-01-01

It is shown that the additive quark model is compatible with the data on double scattering of pions and protons in deuterium. The cross-section for interaction of the hadrons created in the first collision with the second nucleon of the target is determined to be 20-25 mb. (author)

Measurement of the temperature dependence of the ddμ-molecule formation rate in gaseous deuterium at the pressures 1.5 and 0.4 kbar

International Nuclear Information System (INIS)

Bystritskij, V.M.; Dzhelepov, V.P.; Zinov, V.G.

1990-01-01

In the experiment with a gaseous deuterium target of high pressure on the muon beam of the JINR phasotron the temperature dependence of the ddμ-molecule formation rate (λ ddμ ) has been measured. Measurements have been performed with liquid deuterium at the temperature T=20.3 K and with gaseous deuterium at pressure 1500 and 400 bar in the temperature region T=49-300 K. It is found that the value λ ddμ does not depend on the deuterium density for each temperature. The obtained results are in fairly good agreement with theory and with the data of other experiments made with deuterium of sufficiently (one-two order) lower density. 22 refs.; 3 figs.; 1 tab

Desorption dynamics of deuterium in CuCrZr alloy

Science.gov (United States)

Thi Nguyen, Lan Anh; Lee, Sanghwa; Noh, S. J.; Lee, S. K.; Park, M. C.; Shu, Wataru; Pitcher, Spencer; Torcy, David; Guillermain, David; Kim, Jaeyong

2017-12-01

Desorption behavior of deuterium (D2) in CuCrZr alloy was investigated considering sample thickness, loading and baking temperature of deuterium followed by the ITER scopes. Cylindrical specimens of 1, 3, 5 mm thick with 4 mm diameter were exposed to deuterium at a pressure of 25 bar at 120, 240 and 350 °C for 24 h, then baked at 800 °C in a vacuum chamber maintained at a pressure lower than 10-7 Torr. Deuterium desorption characteristics such as desorption rate and amount of deuterium in the sample were estimated by analyzing the desorption peaks monitored with a residual gas analyzer (RGA), and the trapping energy of deuterium was calculated using thermal desorption spectroscopy (TDS). Secondary ion mass spectroscopy (SIMS) results showed that deuterium atoms embedded in the sample at a depth of less than 15 μm and desorbed as low as 400 °C. All absorbed deuterium atoms in the specimen were completely retrieved by dynamic pumping at 800 °C in 15 min. The desorption rate of deuterium per unit area was inversely proportional to the increment of the thickness of the sample, and was proportional to the loading temperature. Based on the assumption that a uniform distribution of interstitial sites for deuterium follows the Femi-Dirac statistics, the result of TDS demonstrated that the CuCrZr alloy has two types of trapping energies, which were estimated to be 62 and 79 kJ/mol.

Beam splitting to improve target life in neutron generators

International Nuclear Information System (INIS)

Farrell, J.P.

1976-01-01

In a neutron generator in which a tritium-titanium target is bombarded by a deuterium ion beam, the target half-life is increased by separating the beam with a weak magnetic field to provide three separate beams of atomic, diatomic, and triatomic deuterium ions which all strike the target at different adjacent locations. Beam separation in this manner eliminates the problem of one type ion impairing the neutron generating efficiency of other type ions, thereby effecting more efficient utilization of the target material

Method for nondestructive fuel assay of laser fusion targets

Science.gov (United States)

Farnum, Eugene H.; Fries, R. Jay

1976-01-01

A method for nondestructively determining the deuterium and tritium content of laser fusion targets by counting the x rays produced by the interaction of tritium beta particles with the walls of the microballoons used to contain the deuterium and tritium gas mixture under high pressure. The x rays provide a direct measure of the tritium content and a means for calculating the deuterium content using the initial known D-T ratio and the known deuterium and tritium diffusion rates.

Method of deuterium isotope separation using ethylene and ethylene dichloride

International Nuclear Information System (INIS)

Benson, S.W.

1982-01-01

Compounds enriched in deuterium may be obtained from ethylene, vinyl chloride, 1,2-dichloroethane, or propylene by laser isotope separation. Normal molecules of these organic compounds are exposed to infrared laser radiation of a suitable wavelength. Substantially all of the deuterium-containing molecules exposed to the laser can be selectively dissociated and the deuterium-containing products separated from the starting material and other reaction products. The deuterium-containing molecules can be burned to form water with an enriched deuterium content, or pyrolized to form hydrogen gas enriched in deuterium

The hydrogen and deuterium concentrations in chondrites

International Nuclear Information System (INIS)

Robert, F.; Merlivat, L.

1978-01-01

Water and isotopic concentration of H 2 O + are reported. It shows a correlation between the water, the deuterium concentrations and the petrologic types of chondrites. The Chainpur meteorite has been divided into several mineralogical fractions and the results are reported. The results of Orgueil are also reported. The correlation shows that as the sulfate content increases, the water and deuterium contents decrease. The terrestrial contamination is discussed and possible deuterium variation models are presented

Analyzing powers and proton spin transfer coefficients in the elastic scattering of 800 MeV polarized protons from an L-type polarized deuteron target at small momentum transfers

International Nuclear Information System (INIS)

Adams, D.L.

1986-10-01

Analyzing powers and spin transfer coefficients which describe the elastic scattering of polarized protons from a polarized deuteron target have been measured. The energy of the proton beam was 800 MeV and data were taken at laboratory scattering angles of 7, 11, 14, and 16.5 degrees. One analyzing power was also measured at 180 degrees. Three linearly independent orientations of the beam polarization were used and the target was polarized parallel and antiparallel to the direction of the beam momentum. The data were taken with the high resolution spectrometer at the Los Alamos Meson Physics Facility (experiment 685). The results are compared with multiple scattering predictions based on Dirac representations of the nucleon-nucleon scattering matrices. 27 refs., 28 figs., 4 tabs

Deuterium behavior in first-wall materials for nuclear fusion

International Nuclear Information System (INIS)

Bernard, E.

2012-01-01

Plasma-wall interactions play an important part while choosing materials for the first wall in future fusion reactors. Moreover, the use of tritium as a fuel will impose safety limits regarding the total amount present in the tokamak. Previous analyses of first-wall samples exposed to fusion plasma highlighted an in-bulk migration of deuterium (as an analog to tritium) in carbon materials. Despite its limited value, this retention is problematic: contrary to co-deposited layers, it seems very unlikely to recover easily the deuterium retained in such a way. Because of the difficult access to in situ samples, most published studies on the subject were carried out using post-mortem sample analysis. In order to access to the dynamic of the phenomenon and come apart potential element redistribution during storage, we set up a bench intended for simultaneous low-energy ion implantation, reproducing the deuterium interaction with first-wall materials, and high-energy micro beam analysis. Nuclear reaction analysis performed at the micrometric scale (μNRA) allows to characterize deuterium repartition profiles in situ. This analysis technique was confirmed to be non-perturbative of the mechanisms studied. We observed on the experimental data set that the material surface (0-1 μm) display a high and nearly constant deuterium content, with a uniform distribution. On the contrary, in-bulk deuterium (1-11 μm) localizes in preferential trapping sites related to the material microstructure. In-bulk deuterium inventory seems to increase with the incident fluence, in spite of the wide data scattering attributed to the structure variation of studied areas. Deuterium saturation at the surface as well as in-depth migration are instantaneous; in-vacuum storage leads to a small deuterium global desorption. Observations made via μNRA were coupled with results from other characterization techniques. X-ray μtomography allowed to identify porosities as the preferential trapping sites

Method for nondestructive fuel assay of laser fusion targets

International Nuclear Information System (INIS)

Farnum, E.H.; Fries, R.J.

1976-01-01

A method is described for nondestructively determining the deuterium and tritium content of laser fusion targets by counting the x rays produced by the interaction of tritium beta particles with the walls of the microballoons used to contain the deuterium and tritium gas mixture under high pressure. The x rays provide a direct measure of the tritium content and a means for calculating the deuterium content using the initial known D-T ratio and the known deuterium and tritium diffusion rates

Deuterium retention in liquid lithium

International Nuclear Information System (INIS)

Baldwin, M.J.; Doerner, R.P.; Luckhardt, S.C.; Conn, R.W.

2002-01-01

Measurements of deuterium retention in samples of lithium exposed in the liquid state to deuterium plasma are reported. Retention was measured as a function of plasma ion dose in the range 6x10 19 -4x10 22 D atoms and exposure temperature between 523 and 673 K using thermal desorption spectrometry. The results are consistent with the full uptake of all deuterium ions incident on the liquid metal surface and are found to be independent of the temperature of the liquid lithium over the range explored. Full uptake, consistent with very low recycling, continues until the sample is volumetrically converted to lithium deuteride. This occurs for exposure temperatures where the gas pressure during exposure was both below and slightly above the corresponding decomposition pressure for LiD in Li. (author)

Geissen polarization facility. I. Lambshift source

Energy Technology Data Exchange (ETDEWEB)

Arnold, W; Berg, H; Krause, H H; Ulbricht, J; Clausnitzer, G [Giessen Univ. (Germany, F.R.). Strahlenzentrum

1977-06-15

A source for the production of polarized negative hydrogen or deuterium ions following the Lambshift method is described. A duoplasmatron with expansion cup and extended ion optics is used. The polarization is generated by a diabetic zero field passage of the metastable atoms. For precision experiments the polarization can be switched 'on' and 'off' with a frequency of 1 kHz by a disturbance with a transverse magnetic field. The quantization axis can be rotated with a Wien filter. All source components are installed in a compact vacuum chamber, which allows high effective pumping speeds. The overal length of the source including the Wien filter is 1.7m. With a 10mm diameter cesium canal typical H/sup -/ currents of 0.6-0.75 ..mu..A (P=0.7 to 0.75) and maximum currents of 0.9..mu..A are obtained.

Nuclear processes in deuterium/natural hydrogen-metal systems

International Nuclear Information System (INIS)

Zelensky, V.F.

2013-01-01

The survey presents the analysis of the phenomena taking place in deuterium - metal and natural hydrogen - metal systems under cold fusion experimental conditions. The cold fusion experiments have shown that the generation of heat and helium in the deuterium-metal system without emission of energetic gamma-quanta is the result of occurrence of a chain of chemical, physical and nuclear processes observed in the system, culminating in both the fusion of deuterium nuclei and the formation of a virtual, electron-modified excited 4He nucleus. The excitation energy of the helium nucleus is transferred to the matrix through emission of conversion electrons, and that, under appropriate conditions, provides a persistent synthesis of deuterium. The processes occurring in the deuterium/natural hydrogen - metal systems have come to be known as chemonuclear DD- and HD-fusion. The mechanism of stimulation of weak interaction reactions under chemonuclear deuterium fusion conditions by means of strong interaction reactions has been proposed. The results of numerous experiments discussed in the survey bear witness to the validity of chemonuclear fusion. From the facts discussed it is concluded that the chemonuclear deuterium fusion scenario as presented in this paper may serve as a basis for expansion of deeper research and development of this ecologically clean energy source. It is shown that the natural hydrogen-based system, containing 0.015% of deuterium, also has good prospects as an energy source. The chemonuclear fusion processes do not require going beyond the scope of traditional physics for their explanation

Setup and proof of principle of SAPIS (Stored Atoms Polarized Ion Source), a novel source of polarized H{sup -}/D{sup -} ions; Aufbau und Funktionsnachweis von SAPIS (Stored Atoms Polarized Ion Source), einer neuartigen Quelle polarisierter H{sup -}/D{sup -}-Ionen

Energy Technology Data Exchange (ETDEWEB)

Emmerich, R.

2007-02-14

The objective of this work was the setup and the proof-of-principle of a new type of negative polarized hydrogen or deuterium ion source, which is based on the charge-exchange reaction (vector)H{sup 0}+Cs{sup 0}{yields}(vector)H{sup -}+Cs{sup +}, as for instance the Colliding-Beams-Source (CBS) at the Cooler Synchrotron COSY in Juelich. In contrast to the CBS, the use of a storage cell for the charge-exchange region promises an increase in H{sup -} current by at least an order of magnitude without considerable polarization losses. For these purposes, a new laboratory was equipped and both a polarized hydrogen/deuterium atomic beam source and an intense neutral cesium-beam source have been build-on. A Lambshift polarimeter, which allows the measurement of the nuclear polarization of the atomic as well as ionic beams, was completed with the construction of a new spin-filter. After commissioning and optimizing each of these sources, a storage cell was developed and installed in the charge-exchange region with a magnetic field. Additionally, components for the extraction, detection and analysis of the negative ion beam were installed. Following the decisive proof of principle, investigation of the properties of the storage cell, especially as to H recombination and depolarisation, was begun. Furthermore, a number of software programs was developed for the control and monitoring of different components of the sources as well as a universal measuring software for the complete installation, including the measurement and calculation of the beam polarization. At the same time, the remote control system of the Cologne source of polarized ions LASCO at the FN tandem accelerator was completely modernized. (orig.)

Catalyzed deuterium fueled tokamak reactors

International Nuclear Information System (INIS)

Southworth, F.H.

1977-01-01

Catalyzed deuterium fuel presents several advantages relative to D-T. These are, freedom from tritium breeding, high charged particle power fraction and lowered neutron energy deposition in the blanket. Higher temperature operation, lower power densities and increased confinement are simultaneously required. However, the present study has developed designs which have capitalized upon the advantages of catalyzed deuterium to overcome the difficulties associated with the fuel while obtaining high efficiency

Deuterium as a tracer in coal liquefaction. Pt. 1

International Nuclear Information System (INIS)

Wilson, M.A.; Collin, P.J.; Barron, P.F.; Vassallo, A.M.

1982-01-01

Deuterium has been used to trace the pathways by which hydrogen reacts with an Australian bituminous coal (Liddell) in the presence of a nickel/molybdenum catalyst. The results show that at 400 0 C extensive scrambling of hydrogen and deuterium occurs among aromatic and α to aromatic aliphatic hydrogen and deuterium substituents. Deuterium can enter all structural groups in both asphaltene and hexane-soluble fractions of the coal-derived liquids, but it enters aromatic and α to aromatic groups in preference to alkyl groups remote from aromatic rings. Thus the results indicate that hydrogen atoms are very mobile during coal hydrogenation. Deuterium from deuterium oxide generated during conversion can also be incorporated into the coal-derived liquids. During coal hydrogenation, the eventual fate of much of the hydrogen in the gas phase is to substitute for hydrogen already in the coal. (Auth.)

In-medium modification of pion-pairs on deuterium

Energy Technology Data Exchange (ETDEWEB)

Lugert, Stefan

2007-11-23

In this thesis the quasi free photo production of pion pairs on bound nucleons {gamma}+A{yields} {pi}{pi}(A-1)+N is analyzed for liquid Deuterium. A pioneering experiment with a photon beam was performed by the TAPS collaboration at the accelerator facility MAMI-B in Mainz in 1999. This measurement observed an invariant mass shift of the isoscalar {pi}{sup 0}{pi}{sup 0} channel with increasing atomic number as well. Due to the poor statistics, the significance of the data was however limited. The experiment described in this work reached a much higher statistical significance, allowing a review of the old data. In this experiment, the TAPS detector was used as a forward wall in combination with the Crystal Ball detector to achieve almost the complete 4{pi} solid angle coverage for particle detection at the MAMI accelerator facility. The installation of the experimental setup started at the end of 2003. The new readout electronics for the BaF{sub 2} crystals was used for the first time. Between June 2004 and April 2005 measurements on several targets were performed, including the lD{sub 2} data which has been analyzed in this work. The analysis of the Deuterium data is an essential contribution to understanding the ongoing processes for two reasons. Firstly, there is the possibility to compare the solid targets and Hydrogen to the lightest nucleus having Fermi motion included but the lowest possible nuclear volume, the Deuterium. For the second reason, there are no data for the mass differential cross section on the neutron available for the mentioned channels. Analyzing the Deuterium data and subtracting the published proton data, the cross section on the neutron gets accessible. An essential question for the theory is whether the cross section on neutron and proton are the same or how much they differ in the relevant energy regime. To determine the absolute cross section, the efficiency of the detector system is required. To provide this efficiency, I also

In-medium modification of pion-pairs on deuterium

International Nuclear Information System (INIS)

Lugert, Stefan

2007-01-01

In this thesis the quasi free photo production of pion pairs on bound nucleons γ+A→ ππ(A-1)+N is analyzed for liquid Deuterium. A pioneering experiment with a photon beam was performed by the TAPS collaboration at the accelerator facility MAMI-B in Mainz in 1999. This measurement observed an invariant mass shift of the isoscalar π 0 π 0 channel with increasing atomic number as well. Due to the poor statistics, the significance of the data was however limited. The experiment described in this work reached a much higher statistical significance, allowing a review of the old data. In this experiment, the TAPS detector was used as a forward wall in combination with the Crystal Ball detector to achieve almost the complete 4π solid angle coverage for particle detection at the MAMI accelerator facility. The installation of the experimental setup started at the end of 2003. The new readout electronics for the BaF 2 crystals was used for the first time. Between June 2004 and April 2005 measurements on several targets were performed, including the lD 2 data which has been analyzed in this work. The analysis of the Deuterium data is an essential contribution to understanding the ongoing processes for two reasons. Firstly, there is the possibility to compare the solid targets and Hydrogen to the lightest nucleus having Fermi motion included but the lowest possible nuclear volume, the Deuterium. For the second reason, there are no data for the mass differential cross section on the neutron available for the mentioned channels. Analyzing the Deuterium data and subtracting the published proton data, the cross section on the neutron gets accessible. An essential question for the theory is whether the cross section on neutron and proton are the same or how much they differ in the relevant energy regime. To determine the absolute cross section, the efficiency of the detector system is required. To provide this efficiency, I also developed the MonteCarlo simulation using a

Predicting big bang deuterium

Energy Technology Data Exchange (ETDEWEB)

Hata, N.; Scherrer, R.J.; Steigman, G.; Thomas, D.; Walker, T.P. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States)

1996-02-01

We present new upper and lower bounds to the primordial abundances of deuterium and {sup 3}He based on observational data from the solar system and the interstellar medium. Independent of any model for the primordial production of the elements we find (at the 95{percent} C.L.): 1.5{times}10{sup {minus}5}{le}(D/H){sub {ital P}}{le}10.0{times}10{sup {minus}5} and ({sup 3}He/H){sub {ital P}}{le}2.6{times}10{sup {minus}5}. When combined with the predictions of standard big bang nucleosynthesis, these constraints lead to a 95{percent} C.L. bound on the primordial abundance deuterium: (D/H){sub best}=(3.5{sup +2.7}{sub {minus}1.8}){times}10{sup {minus}5}. Measurements of deuterium absorption in the spectra of high-redshift QSOs will directly test this prediction. The implications of this prediction for the primordial abundances of {sup 4}He and {sup 7}Li are discussed, as well as those for the universal density of baryons. {copyright} {ital 1996 The American Astronomical Society.}

Equilibrium deuterium isotope effect of surprising magnitude

International Nuclear Information System (INIS)

Goldstein, M.J.; Pressman, E.J.

1981-01-01

Seemingly large deuterium isotope effects are reported for the preference of deuterium for the α-chloro site to the bridgehead or to the vinyl site in samples of anti-7-chlorobicyclo[4.3.2]undecatetraene-d 1 . Studies of molecular models did not provide a basis for these large equilibrium deuterium isotope effects. The possibility is proposed that these isotope effects only appear to be large for want of comparison with isotope effects measured for molecules that might provide even greater contrasts in local force fields

Deuterium trapping in carbon fiber composites under high fluence

International Nuclear Information System (INIS)

Airapetov, A.A.; Begrambekov, L.B.; Kuzmin, A.A.; Shigin, P.A.; Zakharov, A.M.

2010-01-01

The paper is devoted to investigation of deuterium trapping in CFC, dance graphite MPG-8 and pyrolytic graphite (PG) under plasma ion- and electron irradiation. Number of specific features of deuterium trapping and retention under plasma ion and electron irradiation is presented and discussed. In particular it is shown that 1) deuterium trapping takes place even when energy of impinging ions approaches zero; 2) deuterium is trapped under irradiation by plasma electrons; 3) under irradiation at equal fluences deuterium trapping is higher, when ion flux is smaller. High energy ion penetrating the surfaces are trapped in the traps created at the expense of their kinetic energy. The process may be named 'kinetic trapping'. Under low energy (smaller than 200 eV) electron and/or ion irradiation the energy of inelastic interaction on the surface provides creation of active centers, which initiate dissociation of deuterium sorbed on the surface, penetration of deuterium atoms into graphite and their trapping in specific low energy traps. The term 'potential trapping' is proposed for this type of trapping. Under high energy irradiation such atoms can fill the traps formed through kinetic mechanism. Origination of moveable deuterium atoms from the layer of surface sorption seems to be time dependent process and it is a reason of increase of trapping along with irradiation time. New features of deuterium trapping and retention in graphite evaluated in this study offer new opportunities for analysis and correct estimation of hydrogen isotope trapping and retention in tokamaks having graphite tiles. (authors)

Deuterium fractionation in dense interstellar clouds

International Nuclear Information System (INIS)

Millar, T.J.; Bennett, A.; Herbst, E.

1989-01-01

The time-dependent gas-phase chemistry of deuterium fractionation in dense interstellar clouds ranging in temperature between 10 and 70 K was investigated using a pseudo-time-dependent model similar to that of Brown and Rice (1986). The present approach, however, considers much more complex species, uses more deuterium fractionation reactions, and includes the use of new branching ratios for dissociative recombinations reactions. Results indicate that, in cold clouds, the major and most global source of deuterium fractionation is H2D(+) and ions derived from it, such as DCO(+) and H2DO(+). In warmer clouds, reactions of CH2D(+), C2HD(+), and associated species lead to significant fractionation even at 70 K, which is the assumed Orion temperature. The deuterium abundance ratios calculated at 10 K are consistent with those observed in TMC-1 for most species. However, a comparison between theory and observatiom for Orion, indicates that, for species in the ambient molecular cloud, the early-time results obtained with the old dissociative recombination branching ratios are superior if a temperature of 70 K is utilized. 60 refs

Deuterium fractionation in dense interstellar clouds

Science.gov (United States)

Millar, T. J.; Bennett, A.; Herbst, Eric

1989-05-01

The time-dependent gas-phase chemistry of deuterium fractionation in dense interstellar clouds ranging in temperature between 10 and 70 K was investigated using a pseudo-time-dependent model similar to that of Brown and Rice (1986). The present approach, however, considers much more complex species, uses more deuterium fractionation reactions, and includes the use of new branching ratios for dissociative recombinations reactions. Results indicate that, in cold clouds, the major and most global source of deuterium fractionation is H2D(+) and ions derived from it, such as DCO(+) and H2DO(+). In warmer clouds, reactions of CH2D(+), C2HD(+), and associated species lead to significant fractionation even at 70 K, which is the assumed Orion temperature. The deuterium abundance ratios calculated at 10 K are consistent with those observed in TMC-1 for most species. However, a comparison between theory and observatiom for Orion, indicates that, for species in the ambient molecular cloud, the early-time results obtained with the old dissociative recombination branching ratios are superior if a temperature of 70 K is utilized.

NMR parallel Q-meter with double-balanced-mixer detection for polarized target experiments

International Nuclear Information System (INIS)

Boissevain, J.; Tippens, W.B.

1983-01-01

A constant-voltage, parallel-tuned nuclear magnetic resonance (NMR) circuit, patterned after a Liverpool design, has been developed for polarized target experiments. Measuring the admittance of the resonance circuit allows advantageous use of double-balanced mixer detection. The resonant circuit is tolerant of stray capacitance between the NMR coil and the target cavity, thus easing target-cell-design constraints. The reference leg of the circuit includes a voltage-controlled attenuator and phase shifter for ease of tuning. The NMR output features a flat background and has good linearity and stability

Deuterium desorption from tungsten using laser heating

Directory of Open Access Journals (Sweden)

J.H. Yu

2017-08-01

Full Text Available Retention and desorption of hydrogenic species need to be accurately modeled to predict the tritium inventory of next generation fusion devices, which is needed both for tritium fuel recovery and for tritium safety concerns. In this paper, experiments on thermal desorption of deuterium from intrinsic polycrystalline tungsten defects using laser heating are compared to TMAP-7 modeling. The samples during deuterium plasma exposure were at a temperature of 373K for this benchmark study with ion fluence of 0.7–1.0 ×1024Dm−2. Following plasma exposure, a fiber laser (λ= 1100nm heated the samples to peak surface temperatures ranging from ∼500 to 1400K with pulse widths from 10ms to 1s, and 1 to 10 pulses applied to each sample. The remaining deuterium retention was measured using temperature programmed desorption (TPD. Results show that > 95% of deuterium is desorbed when the peak surface temperature reached ∼950K for > 1s. TMAP-7 is used to predict deuterium desorption from tungsten for a range of surface temperatures and heating durations, and is compared to previous work on desorption from beryllium codeposits.

Spin filtering neutrons with a proton target dynamically polarized using photo-excited triplet states

International Nuclear Information System (INIS)

Haag, M.; Brandt, B. van den; Eichhorn, T.R.; Hautle, P.; Wenckebach, W.Th.

2012-01-01

In a test of principle a neutron spin filter has been built, which is based on dynamic nuclear polarization (DNP) using photo-excited triplet states. This DNP method has advantages over classical concepts as the requirements for cryogenic equipment and magnets are much relaxed: the spin filter is operated in a field of 0.3 T at a temperature of about 100 K and has performed reliably over periods of several weeks. The neutron beam was also used to analyze the polarization of the target employed as a spin filter. We obtained an independent measurement of the proton spin polarization of ∼0.13 in good agreement with the value determined with NMR. Moreover, the neutron beam was used to measure the proton spin polarization as a function of position in the naphthalene sample. The polarization was found to be homogeneous, even at low laser power, in contradiction to existing models describing the photo-excitation process.

NUCLEON POLARIZATION IN 3-BODY MODELS OF POLARIZED LI-6

NARCIS (Netherlands)

SCHELLINGERHOUT, NW; KOK, LP; COON, SA; ADAM, RM

1993-01-01

Just as He-3 --> can be approximately characterized as a polarized neutron target, polarized Li-6D has been advocated as a good isoscalar nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed ''alpha + deuteron'' picture of Li-6,

Deuterium release from Li-D films exposed to atmospheric gases

Energy Technology Data Exchange (ETDEWEB)

Gasparyan, Yu. M., E-mail: YMGasparyan@mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe highway 31, Moscow (Russian Federation); Popkov, A.S.; Krat, S.A.; Pisarev, A.A.; Vasina, Ya. A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe highway 31, Moscow (Russian Federation); Lyublinski, I.E. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe highway 31, Moscow (Russian Federation); JSC “Red Star”, Electrolitniy proezd 1a, Moscow (Russian Federation); Vertkov, A.V. [JSC “Red Star”, Electrolitniy proezd 1a, Moscow (Russian Federation)

2017-04-15

Highlights: • The major part of deuterium desorbs from Li-D films in a very sharp peak at 670–710 K. • Exposure on air leads to intensive deuterium release from the Li-D film at room temperature. • Interaction with water vapor plays a major role in deuterium release from lithium films in the air. - Abstract: Deuterium release from Li-D films co-deposited on a Mo substrate at room temperature in magnetron discharge was investigated by means of thermal desorption spectroscopy. The deuterium concentration in the films was estimated to be D/Li = (14 ± 4)%. TDS from Li-D films just after co-deposition had a sharp peak at 670–710 K. Exposure of deposited Li-D films in the air at room temperature led to deuterium release. Comparison of release in air, water vapor, nitrogen, and oxygen demonstrated that water plays a major role in deuterium release in the air at low temperatures.

SAIDE: A Semi-Automated Interface for Hydrogen/Deuterium Exchange Mass Spectrometry.

Science.gov (United States)

Villar, Maria T; Miller, Danny E; Fenton, Aron W; Artigues, Antonio

2010-01-01

Deuterium/hydrogen exchange in combination with mass spectrometry (DH MS) is a sensitive technique for detection of changes in protein conformation and dynamics. Since temperature, pH and timing control are the key elements for reliable and efficient measurement of hydrogen/deuterium content in proteins and peptides, we have developed a small, semiautomatic interface for deuterium exchange that interfaces the HPLC pumps with a mass spectrometer. This interface is relatively inexpensive to build, and provides efficient temperature and timing control in all stages of enzyme digestion, HPLC separation and mass analysis of the resulting peptides. We have tested this system with a series of standard tryptic peptides reconstituted in a solvent containing increasing concentration of deuterium. Our results demonstrate the use of this interface results in minimal loss of deuterium due to back exchange during HPLC desalting and separation. For peptides reconstituted in a buffer containing 100% deuterium, and assuming that all amide linkages have exchanged hydrogen with deuterium, the maximum loss of deuterium content is only 17% of the label, indicating the loss of only one deuterium molecule per peptide.

Long Term Retention of Deuterium and Tritium in Alcator C-Mod

International Nuclear Information System (INIS)

FIORE, C.; LABOMBARD, B.; LIPSCHULTZ, B.; PITCHER, C.S.; SKINNER, C.H.; WAMPLER, WILLIAM R.

1999-01-01

We estimate the total in-vessel deuterium retention in Alcator C-Mod from a run campaign of about 1090 plasmas. The estimate is based on measurements of deuterium retained on 22 molybdenum tiles from the inner wall and divertor. The areal density of deuterium on the tiles was measured by nuclear reaction analysis. From these data, the in-vessel deuterium inventory is estimated to be about 0.1 gram, assuming the deuterium coverage is toroidally symmetric. Most of the retained deuterium is on the walls of the main plasma chamber, only about 2.5% of the deuterium is in the divertor. The D coverage is consistent with a layer saturated by implantation with ions and charge-exchange neutrals from the plasma. This contrasts with tokamaks with carbon plasma-facing components (PFC's) where long-term retention of tritium and deuterium is large and mainly in the divertor due to codeposition with carbon eroded by the plasma. The low deuterium retention in the C-Mod divertor is mainly due to the absence of carbon PFC's in C-Mod and the low erosion rate of Mo

Measurement of the polarized neutron---polarized 3He total cross section

International Nuclear Information System (INIS)

Keith, C.D.; Gould, C.R.; Haase, D.G.; Seely, M.L.; Huffman, P.R.; Roberson, N.R.; Tornow, W.; Wilburn, W.S.

1995-01-01

The first measurements of polarized neutron--polarized 3 He scattering in the few MeV energy region are reported. The total cross section difference Δσ T for transversely polarized target and beam has been measured for neutron energies between 1.9 and 7.5 MeV. Comparison is made to predictions of Δσ T using various descriptions of the 4 He continuum. A brute-force polarized target of solid 3 He has been developed for these measurements. The target is 4.3x10 22 atoms/cm 2 thick and is polarized to 38% at 7 Telsa and 12 mK. copyright 1995 American Institute of Physics

Dynamic nuclear polarization tests in some polymers for polarized targets

International Nuclear Information System (INIS)

Brandt, B. van den; Hautle, P.; Konter, J.A.; Mango, S.; Bunyatova, E.I.

1998-01-01

The results of dynamic polarization tests in polyethylene (PE) and ethylene propylene copolymer (EPC), doped with the stable free radical 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), are presented. Sizable proton polarizations have been achieved in a magnetic field of 2.5 T at a temperature below 0.3 K and 5T at 1 K

Compared studies of natural and artificial deuterium depleted water

International Nuclear Information System (INIS)

Butnaru, Gallia; Mihacea, Sorina; Sirbovan, Alina; Butnariu, H.; Titescu, Gh.

2001-01-01

The biological influence of the deuterium on animals was studied insensitively in the last years. When animal cell cultures were analyzed it turned out an inhibition of the development, due to the reduced deuterium concentration. In the in vivo experiments a decreasing of the number of tumoral cells was pointed out when performing the depleted water treatment. It is obvious that the presence of deuterium in water is necessary for the development, especially for the tumoral cell proliferation. The aim of this work was to establish influence of the natural and artificial deuterium depleted water on the vegetal organisms development. For this purpose, the developmental stages of Lactuca sativa L. growth were followed. The experimental data were compared with the data obtained with distilled water. The birch, wine sap and some fruit juices are considered 'natural depleted' water sources because their deuterium content is smaller in comparison to natural water (D 2 =150 ppm). The effect of artificial deuterium depleted water (29 ppm D 2 ) was analyzed in comparison to three types of wine saps, which also have a reduced deuterium concentration (125-130 ppm D 2 ). If the deuterium depleted water was used, the germination percent and the root and shoot length were higher compared to control in the first stages. In wine sap it had a negative effect on germination and development. After three days the plants were transferred to soil and their development was followed. The foliage area was larger for all of the experimental variants compared to control. The differences were without significance when deuterium depleted water was tested but they were high and very significant in case of wine sap. The experiment pointed out a stimulative effect of the artificial deuterium depleted water. In case of wine sap the effect was negative when the contact was direct, but the growth was stimulated after the stress cessation. The first ontogenetic stages were represented by direct action

Deuterium isotope effects on the ring inversion equilibrium in cyclohexane: the A value of deuterium and its origin

International Nuclear Information System (INIS)

Anet, F.A.L.; Kopelevich, M.

1986-01-01

It has been reported recently that the deuterium in cyclohexane-d 1 prefers the equatorial over the axial position by about 200 J/mol (i.e., ca. 50 cal/mol), as shown by three different kinds of NMR measurements. Such an isotope effect is unexpectedly large, and this has led the authors to reinvestigate the problem using Saunder's isotopic perturbation method. The authors thereby established that the free energy difference (the A value for deuterium) is 6.3 +/- 1.5 cal/mol, with deuterium more stable equatorial than axial. This value is supported by molecular mechanics calculations based in part on experimental vibrational frequencies. 17 references, 1 figure

Laser - Polarized HE-3 Target Used for a Precision Measurement of the Neutron Spin Structure

Energy Technology Data Exchange (ETDEWEB)

Romalis, M

2003-11-05

This thesis describes a precision measurement of the deep inelastic neutron spin structure function g{sub 1}{sup n}(x). The main motivation for the experiment is a test of the Bjorken sum rule. Because of smaller statistical errors and broader kinematic coverage than in previous experiments, we are able to study in detail the behavior of the spin structure function g{sub 1}{sup n}(x) for low values of the Bjorken scaling variable x. We find that it has a strongly divergent behavior, in contradiction to the naive predictions of the Regge theory. This calls into question the methods commonly used for extrapolation of g{sub 1}{sup n}(x) to x = 0. The difference between the proton and the neutron spin structure functions is less divergent at low x, so a test of the Bjorken sum rule is possible. We confirm the sum rule with an accuracy of 8%. The experiment was performed at SLAC using a 50 GeV polarized electron beam and a polarized {sup 3}He target. In this thesis the polarized target is described in detail. We used the technique of Rb optical pumping and Rb-He spin exchange to polarize the {sup 3}He. Because of a novel mechanical design our target had the smallest dilution ever achieved for a high density gas target. Since this is a precision measurement, particular efforts were made to reduce the systematic errors due to the uncertainty in the target parameters. Most important parameters were measured by more than one method. We implemented novel techniques for measuring the thickness of the glass windows of the target, the {sup 3}He density, and the polarization. In particular, one of the methods for measuring the gas density relied on the broadening of the Rb optical absorption lines by collisions with {sup 3}He atoms. The calibration of this technique resulted in the most precise measurements of the pressure broadening parameters for {sup 3}He as well as several other gases, which are described in an Appendix. The polarization of the {sup 3}He was also measured by

Development and testing of a deuterium gas target assembly for neutron production via the H-2(d,n)He-3 reaction at a low-energy accelerator facility

International Nuclear Information System (INIS)

Feautrier, D.; Smith, D.L.

1992-03-01

This report describes the development and testing of a deuterium gas target intended for use at a low-energy accelerator facility to produce neutrons for basic research and various nuclear applications. The principle source reaction is H-2(d,n)He-3. It produces a nearly mono-energetic group of neutrons. However, a lower-energy continuum neutron spectrum is produced by the H-2(d;n,p)H-2 reaction and also by deuterons which strike various components in the target assembly. The present target is designed to achieve the following objectives: (1) minimize unwanted background neutron production from the target assembly, (2) provide a relatively low level of residual long-term activity within the target components, (3) have the capacity to dissipate up to 150 watts of beam power with good target longevity, and (4) possess a relatively modest target mass in order to minimize neutron scattering from the target components. The basic physical principles that have to be considered in designing an accelerator target are discussed and the major engineering features of this particular target design are outlined. The results of initial performance tests on this target are documented and some conclusions concerning the viability of the target design are presented

Tritium target manufacturing for use in accelerators

Science.gov (United States)

Bach, P.; Monnin, C.; Van Rompay, M.; Ballanger, A.

2001-07-01

As a neutron tube manufacturer, SODERN is now in charge of manufacturing tritium targets for accelerators, in cooperation with CEA/DAM/DTMN in Valduc. Specific deuterium and tritium targets are manufactured on request, according to the requirements of the users, starting from titanium target on copper substrate, and going to more sophisticated devices. A wide range of possible uses is covered, including thin targets for neutron calibration, thick targets with controlled loading of deuterium and tritium, rotating targets for higher lifetimes, or large size rotating targets for accelerators used in boron neutron therapy. Activity of targets lies in the 1 to 1000 Curie, diameter of targets being up to 30 cm. Special targets are also considered, including surface layer targets for lowering tritium desorption under irradiation, or those made from different kinds of occluders such as titanium, zirconium, erbium, scandium, with different substrates. It is then possible to optimize either neutron output, or lifetime and stability, or thermal behavior.

Deuterium and big bang nucleosynthesis

International Nuclear Information System (INIS)

Burles, S.

2000-01-01

Measurements of deuterium absorption in high redshift quasar absorption systems provide a direct inference of the deuterium abundance produced by big bang nucleosynthesis (BBN). With measurements and limits from five independent absorption systems, we place strong constraints on the primordial ratio of deuterium to hydrogen, (D/H) p = 3.4 ± 0.3 x 10 -5 [1,2]. We employ a direct numerical treatment to improve the estimates of critical reaction rates and reduce the uncertainties in BBN predictions of D/H and 7 Li/H by a factor of three[3] over previous efforts[4]. Using our measurements of (D/H) p and new BBN predictions, we find at 95% confidence the baryon density ρ b = (3.6 ± 0.4) x 10 -31 g cm -3 (Ω b h 2 65 = 0.045 ± 0.006 in units of the critical density), and cosmological baryon-photon ratio η = (5.1 ± 0.6) x 10 -10

MEASUREMENT OF POLARIZATION OBSERVABLES IN VECTOR MESON PHOTOPRODUCTION USING A TRANSVERSELY-POLARIZED FROZEN-SPIN TARGET AND POLARIZED PHOTONS AT CLAS, JEFFERSON LAB

Energy Technology Data Exchange (ETDEWEB)

Roy, Priyashree [Florida State Univ., Tallahassee, FL (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2016-11-30

The study of baryon resonances provides a deeper understanding of the strong interaction because the dynamics and relevant degrees of freedom hidden within them are re ected by the properties of the excited states of baryons. Higher-lying excited states at and above 1.7 GeV/c2 are generally predicted to have strong couplings to final states involving a heavier meson, e. g. one of the vector mesons, ρ, ω φ, as compared to a lighter pseudoscalar meson, e. g. π and η. Decays to the ππΝ final states via πΔ also become more important through the population of intermediate resonances. We observe that nature invests in mass rather than momentum. The excited states of the nucleon are usually found as broadly overlapping resonances which may decay into a multitude of final states involving mesons and baryons. Polarization observables make it possible to isolate single resonance contributions from other interference terms. The CLAS g9 (FROST) experiment, as part of the N* spectroscopy program at Je?erson Laboratory, accumulated photoproduction data using circularly- & linearly-polarized photons incident on a transversely-polarized butanol target (g9b experiment) in the photon energy range 0:3-2:4 GeV & 0:7-2:1 GeV, respectively. In this work, the analysis of reactions and polarization observables which involve two charged pions, either in the fully exclusive reaction γρ -> ρπ+π- or in the semi-exclusive reaction with a missing neutral pion, γρ -> ρπ+π-(π0) will be presented. For the reaction ρπ+π-, eight polarization observables (Is, Ic, Px, Py, Psx; y, Pcx; y) have been extracted. The high statistics data rendered it possible to extract these observables in three dimensions. All of them are first-time measurements. The fairly good agreement of Is, Ic obtained from this analysis with the experimental results from a previous CLAS experiment provides support for the first-time measurements. For the reaction γρ -> ρω -> ρπ+π(π0, five polarization

Development of Efficient and Robust Heteronuclear Cross-Polarization Techniques for Biological Solid-State Nuclear Magnetic Resonance Spectroscopy

DEFF Research Database (Denmark)

Jain, Sheetal Kumar

2014-01-01

→13C and 1H→14N polarization transfers. The deuterium experiments were performed on deuterated glutamine and outer membrane protein G samples, while the nitrogen experiments were carried out on ammonium nitrate and alanine samples. Moreover, experiments with low power on the 2H channel are presented......→13C polarization transfer to facilitate 2-dimensional experiments detecting 14N in the indirect dimension are shown. Finally, to test the polarization transfer efficiency with very large chemical shift anisotropies, 19F→13C polarization transfer experiments for Poly Tetra Fluoro Ethylene (PTFE...

Permeation of deuterium implanted into vanadium alloys

International Nuclear Information System (INIS)

Anderl, R.A.; Longhurst, G.R.; Struttmann, D.A.

1986-05-01

Permeation of deuterium through the vanadium alloy, V-15Cr-5Ti, was investigated using 3-keV, D 3 + ion beams from a small accelerator. The experiments consisted of measurements of the deuterium reemission and permeation rates as a function of implantation fluence for 0.5-mm thick specimens heated to tempertures from 623 to 823 0 K. Implantation-side surface characterization was made by simultaneous measurements of sputtered ions with a secondary ion mass spectrometer (SIMS). Analyses of these measurements indicate that for the experimental conditions used, the steady-state deuterium permeation flux in V-15Cr-5Ti is approximately 18% of the implantation flux. This corresponds to approximately 1000 times that seen in the ferritic steel, HT-9, under comparable conditions. Measurement of deuterium diffusivity in V-15Cr-5Ti using permeation break-through times indicates D = 1.4 x 10 -8 exp(-.11 eV/kT) (m 2 /s)

Progress towards polar-drive ignition for the NIF

Science.gov (United States)

McCrory, R. L.; Betti, R.; Boehly, T. R.; Casey, D. T.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Frenje, J. A.; Froula, D. H.; Gatu-Johnson, M.; Glebov, V. Yu.; Goncharov, V. N.; Harding, D. R.; Hohenberger, M.; Hu, S. X.; Igumenshchev, I. V.; Kessler, T. J.; Knauer, J. P.; Li, C. K.; Marozas, J. A.; Marshall, F. J.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Nilson, P. M.; Padalino, S. J.; Petrasso, R. D.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Séguin, F. H.; Seka, W.; Short, R. W.; Shvydky, A.; Skupsky, S.; Soures, J. M.; Stoeckl, C.; Theobald, W.; Yaakobi, B.; Zuegel, J. D.

2013-11-01

The University of Rochester's Laboratory for Laser Energetics (LLE) performs direct-drive inertial confinement fusion (ICF) research. LLE's Omega Laser Facility is used to study direct-drive ICF ignition concepts, developing an understanding of the underlying physics that feeds into the design of ignition targets for the National Ignition Facility (NIF). The baseline symmetric-illumination, direct-drive-ignition target design consists of a 1.5 MJ multiple-picket laser pulse that generates four shock waves (similar to the NIF baseline indirect-drive design) and is predicted to produce a one-dimensional (1D) gain of 48. LLE has developed the polar-drive (PD) illumination concept (for NIF beams in the x-ray-drive configuration) to allow the pursuit of direct-drive ignition without significant reconfiguration of the beam paths on the NIF. Some less-invasive changes in the NIF infrastructure will be required, including new phase plates, polarization rotators, and a PD-specific beam-smoothing front end. A suite of PD ignition designs with implosion velocities from 3.5 to 4.3 × 107 cm s-1 are predicted to have significant 2D gains (Collins et al 2012 Bull. Am. Phys. Soc. 57 155). Verification of the physics basis of these simulations is a major thrust of direct-drive implosion experiments on both OMEGA and the NIF. Many physics issues are being examined with symmetric beam irradiation on OMEGA, varying the implosion parameters over a wide region of design space. Cryogenic deuterium-tritium target experiments with symmetric irradiation have produced areal densities of ˜0.3 g cm-2, ion temperatures over 3 keV, and neutron yields in excess of 20% of the ‘clean’ 1D predicted value. The inferred Lawson criterion figure of merit (Betti R. et al 2010 Phys. Plasmas 17 058102) has increased from 1.7 atm s (IAEA 2010) to 2.6 atm s.

Energy Levels of Hydrogen and Deuterium

Science.gov (United States)

SRD 142 NIST Energy Levels of Hydrogen and Deuterium (Web, free access)   This database provides theoretical values of energy levels of hydrogen and deuterium for principle quantum numbers n = 1 to 200 and all allowed orbital angular momenta l and total angular momenta j. The values are based on current knowledge of the revelant theoretical contributions including relativistic, quantum electrodynamic, recoil, and nuclear size effects.

Study of a polarized proton source for a cyclotron using a high frequency transition (1961)

International Nuclear Information System (INIS)

Thirion, J.; Beurtey, R.; Papineau, A.

1961-01-01

The authors have developed an experimental unit yielding a jet of hydrogen or deuterium atoms in which the protons and deutons are polarized. By use of the 'adiabatic passage' method a proton polarisation approaching 100 per cent is assured. (authors) [fr

Spin-dependent Nucleon Structure Studies at MIT/Bates

International Nuclear Information System (INIS)

Botto, T.

2005-01-01

We present preliminary results from recent measurements of the proton, neutron and deuterium electro-magnetic form factors obtained by the BLAST collaboration at the MIT/Bates Linear Accelerator Facility. BLAST (Bates Large Acceptance Spectrometer Toroid) is a large-acceptance multi-purpose detector dedicated to studies of exclusive spin-dependent electron scattering from internal polarized targets. BLAST makes use of stored electron beam currents in excess of 150 mA with a 60-70% polarization. The electron beam is let through a 15 mm diameter, 60 cm long open-ended storage cell which is fed with ultra-pure, high-polarization H1,D1 gas from an Atomic Beam Source. The target polarization can be rapidly reversed between different vector and tensor target states, thus minimizing systematic uncertainties. The target spin can be oriented to any in-plane direction via a set of Helmholtz coils. Target polarizations in the storage cell of up to 80% (vector) and 70% (tensor) have been routinely achieved over a period of several months. Our data on the D-vector(e-vector,e'n) reaction off vector polarized deuterium allow for a unique extraction of the neutron charge form factor G E n . At same time, complementary measurements of G M n , T20 and the spin-dependent nucleon momentum distributions in deuterium are obtained via the D-vector(e-vector,e'), D (e-vector,e'd) and D (e-vector,e'p) reactions. In addition, BLAST data on vector polarized hydrogen will provide novel measurements of the GE/GM form-factor ratio on the proton as well as of the spin-dependent electro-excitation of the Δ(1232) resonance. Such comprehensive program on few body physics is now well underway and preliminary data will be presented

Site occupation state of deuterium atoms in fcc Fe

International Nuclear Information System (INIS)

Aoki, Katsutoshi; Machida, Akihiko; Saitoh, Hiroyuki; Hattori, Takanori; Sano-Furukawa, Asami

2015-01-01

The deuterization process of fcc Fe to form solid-solution fcc FeD x was investigated by in situ neutron diffraction measurements at high temperature and high pressure. In a completely deuterized specimen at 988 K and 6.3 GPa, deuterium atoms occupy the octahedral and tetrahedral interstitial sites with an occupancy of 0.532(9) and 0.056(5), respectively, giving a deuterium composition x of 0.64(1). During deuterization, the metal-lattice expands approximately linearly with deuterium composition at a rate of 2.21 Å 3 per deuterium atom. The minor occupation of tetrahedral site is likely driven by the intersite movement of deuterium atoms along the <111> direction in the fcc metal lattice. These results provide implications for the light elements in the Earth's core and the mechanism of hydrogen embrittlement of ferrous metals. (author)

Deuterium retention and desorption behavior in an advanced reduced-activation alloy

Energy Technology Data Exchange (ETDEWEB)

Noh, S.J., E-mail: sjnoh@dankook.ac.kr [Department of Applied Physics, Dankook University, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of); Kim, H.S.; Byeon, W.J.; Shin, H.W. [Department of Applied Physics, Dankook University, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of); Lee, Cheol Eui [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); Lee, S.K. [Nuclear Fusion Development Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

2017-07-15

We present the first experimental results of the deuterium retention and desorption behavior in an advanced reduced-activation alloy (ARAA) under development in Korea. For the in-situ measurement of desorbed gases from samples immediately after irradiation, a thermal desorption spectroscopy (TDS) system clustered with an inductively coupled plasma ion source has been built. Samples were and were not irradiated with helium ions at energies of 1.4, 3.5, and 5.0 keV and then continuously irradiated with 1.7-keV deuterium ions. TDS measurements were performed in situ immediately after deuterium irradiation and after exposure to air for one week. The amount of desorbed deuterium is the largest for the sample without helium irradiation from the TDS results measured in situ immediately after irradiation. Further, the amount of desorbed deuterium is significantly lowered when the helium energy is increased to 3.5 keV with no significant changes thereafter, indicating that the layer formed by implanted helium at near or deeper than the stopping range for 1.7-keV deuterium ions effectively acts as a barrier against deuterium diffusion into the depth. Because of the strong diffusivity of deuterium into the ambient atmosphere, the amounts of desorbed deuterium are greatly reduced for the samples without helium irradiation and with 1.4-keV helium irradiation after exposure to air for one week. In addition, our deuterium results for the ARAA are also compared with the results for F82H by other authors. - Highlights: •The first result of the deuterium retention and desorption in an ARAA is presented. •The ARAA was irradiated with helium and then continuously irradiated with deuterium. •TDS measurements were performed in situ immediately after deuterium irradiation. •TDS measurements were performed after exposure to air for one week. •The effects of helium irradiation and exposure to air were investigated.

Measurement of parity violation in the photodisintegration of deuterium and in the production of Bremsstrahlung on tantalum

International Nuclear Information System (INIS)

Earle, E.D.; McDonald, A.B.; Kidner, S.H.; Clifford, E.T.H.; Hill, J.J.; Keech, G.H.; Chupp, T.E.; Schneider, M.B.

1987-01-01

The circular polarization dependent component of the total cross section for photodisintegration of deuterium has been measured to be (2.7±2.8) x 10 -6 for Bremsstrahlung with an end point of 4.1 MeV and (7.7±5.3) x 10 -6 for an end point of 3.2 MeV. The helicity dependent component of the total cross section for the production of Bremsstrahlung on tantalum by longitudinally polarized electrons has been measured to be (0.63±0.70) x 10 -6 for an electron energy of 4.1 MeV and (3.1±1.5) x 10 -6 at 3.2 MeV. All measurements are in agreement with theoretical predictions for these processes. (author)

Hadron-pair production on transversely polarized targets in semi-inclusive deep inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Braun, Christopher

2014-07-29

Nucleons such as protons and neutrons are composite objects made of quarks, which are bound together by the strong force via the exchange of gluons. The probability of finding a quark of flavor q carrying the momentum fraction x of the fast moving parent nucleon is described by a parton distribution function (PDF) f{sub 1}{sup q}(x), the number density. The spin, an intrinsic angular momentum of elementary particles such as quarks but also of composite objects like nucleons, couples with magnetic fields, which allows one to align it. Taking into account this additional parameter, the spin, the scheme of PDFs in leading twist is expanded by the helicity distribution g{sub 1}{sup q}(x) and the transversity distribution h{sub 1}{sup q}(x). The first distribution covers the case where the nucleon and the quark are longitudinally polarized, while a transverse polarization is taken into account by the latter. A tool for the investigation of the PDFs is inclusive deep inelastic scattering (DIS) of electro-magnetic probes off (un)polarized nucleons at fixed-target experiments. This only gives access to f{sub 1}{sup q}(x) and g{sub 1}{sup q}(x), while the chiral-odd nature of the transversity distribution prevents a measurement without detecting the final hadronic states. However, h{sub 1}{sup q}(x) can be observed in semi-inclusive DIS (SIDIS) in combination with another chiral-odd function like the dihadron fragmentation function H{sub 1} {sup angle} {sup q} in the production of a hadron-pair. The resulting experimental challenge is the reason why f{sub 1}{sup q}(x) and g{sub 1}{sup q}(x) have been investigated for almost four decades, while h{sub 1}{sup q}(x) is still subject to recent measurements and analyses. The 160 GeV/c polarized muon beam of CERN's M2 beamline allows the COMPASS experiment to investigate spin effects using polarized solid-state targets. Since the year 2002 COMPASS has collected unique data sets on transversely polarized targets of lithium

ICRF heating and transport of deuterium-tritium plasmas in TFTR

International Nuclear Information System (INIS)

Murakami, M.; Batchelor, D.B.; Bush, C.E.

1994-01-01

This paper describes results of the first experiments utilizing high-power ion cyclotron range of frequency (ICRF) to heat deuterium-tritium (D-T) plasmas in reactor-relevant regimes on the Tokamak Fusion Test Reactor (TFTR). Results from these experiments have demonstrated efficient core, second harmonic, tritium heating of D-T supershot plasmas with tritium concentrations ranging from 6%--40%. Significant direct ion heating on the order of 60% of the input radio frequency (rf) power has been observed. The measured deposition profiles are in good agreement with two-dimensional modeling code predictions. Confinement in an rf-heated supershot is at least similar to that without rf, and possibly better in the electron channel. Efficient electron heating via mode conversion of fast waves to ion Bernstein waves (IBW) has been demonstrated in ohmic, deuterium-deuterium and DT-neutral beam injection plasmas with high concentrations of minority 3 He (n 3 He /n e > 10%). By changing the 3 He concentration or the toroidal field strength, the location of the mode-conversion radius was varied. The power deposition profile measured with rf power modulation showed that up to 70% of the power can be deposited on electrons at an off-axis position. Preliminary results with up to 4 MW coupled into the plasma by 90-degree phased antennas showed directional propagation of the mode-converted IBW. Heat wave propagation showed no strong inward thermal pinch in off-axis heating of an ohmically-heated (OH) target plasma in TFIR

Submolecular regulation of cell transformation by deuterium depleting water exchange reactions in the tricarboxylic acid substrate cycle.

Science.gov (United States)

Boros, László G; D'Agostino, Dominic P; Katz, Howard E; Roth, Justine P; Meuillet, Emmanuelle J; Somlyai, Gábor

2016-02-01

The naturally occurring isotope of hydrogen ((1)H), deuterium ((2)H), could have an important biological role. Deuterium depleted water delays tumor progression in mice, dogs, cats and humans. Hydratase enzymes of the tricarboxylic acid (TCA) cycle control cell growth and deplete deuterium from redox cofactors, fatty acids and DNA, which undergo hydride ion and hydrogen atom transfer reactions. A model is proposed that emphasizes the terminal complex of mitochondrial electron transport chain reducing molecular oxygen to deuterium depleted water (DDW); this affects gluconeogenesis as well as fatty acid oxidation. In the former, the DDW is thought to diminish the deuteration of sugar-phosphates in the DNA backbone, helping to preserve stability of hydrogen bond networks, possibly protecting against aneuploidy and resisting strand breaks, occurring upon exposure to radiation and certain anticancer chemotherapeutics. DDW is proposed here to link cancer prevention and treatment using natural ketogenic diets, low deuterium drinking water, as well as DDW production as the mitochondrial downstream mechanism of targeted anti-cancer drugs such as Avastin and Glivec. The role of (2)H in biology is a potential missing link to the elusive cancer puzzle seemingly correlated with cancer epidemiology in western populations as a result of excessive (2)H loading from processed carbohydrate intake in place of natural fat consumption. Published by Elsevier Ltd.

Radiation assisted thermonuclear burn wave dynamics in heavy ion fast ignition of cylindrical deuterium-tritium fuel target

International Nuclear Information System (INIS)

Rehman, S.; Kouser, R.; Nazir, R.; Manzoor, Z.; Tasneem, G.; Jehan, N.; Nasim, M.H.; Salahuddin, M.

2015-01-01

Dynamics of thermonuclear burn wave propagation assisted by thermal radiation precursor in a heavy ion fast ignition of cylindrical deuterium-tritium (DT) fuel target are studied by two dimensional radiation hydrodynamic simulations using Multi-2D code. Thermal radiations, as they propagate ahead of the burn wave, suffer multiple reflections and preheat the fuel, are found to play a vital role in burn wave dynamics. After fuel ignition, the burn wave propagates in a steady state manner for some time. Multiple reflection and absorption of radiation at the fuel-tamper interface, fuel ablation and radial implosion driven by ablative shock and fast fusion rates on the fuel axis, at relatively later times, result into filamentary wave front. Strong pressure gradients are developed and sausage like structures behind the front are appeared. The situation leads to relatively reduced and non-uniform radial fuel burning and burn wave propagation. The fuel burning due to DD reaction is also taken into account and overall fusion energy and fusion power density, due to DT and DD reactions, during the burn wave propagation are determined as a function of time. (authors)

Affinity capture of biotinylated proteins at acidic conditions to facilitate hydrogen/deuterium exchange mass spectrometry analysis of multimeric protein complexes

DEFF Research Database (Denmark)

Jensen, Pernille Foged; Jørgensen, Thomas J. D.; Koefoed, Klaus

2013-01-01

Characterization of conformational and dynamic changes associated with protein interactions can be done by hydrogen/deuterium exchange mass spectrometry (HDX-MS) by comparing the deuterium uptake in the bound and unbound state of the proteins. Investigation of local hydrogen/deuterium exchange...... in heteromultimeric protein complexes poses a challenge for the method due to the increased complexity of the mixture of peptides originating from all interaction partners in the complex. Previously, interference of peptides from one interaction partner has been removed by immobilizing the intact protein on beads...... complexes without interference of peptides originating from other interaction partners in the complex. The biotin-streptavidin strategy has been successfully implemented in a model system with two recombinant monoclonal antibodies that target nonoverlapping epitopes on the human epidermal growth factor...

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

International Nuclear Information System (INIS)

Alejo, A.; Kar, S.; Ahmed, H.; Doria, D.; Green, A.; Jung, D.; Lewis, C. L. S.; Nersisyan, G.; Krygier, A. G.; Freeman, R. R.; Clarke, R.; Green, J. S.; Notley, M.; Fernandez, J.; Fuchs, J.; Kleinschmidt, A.; Roth, M.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.

2014-01-01

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C 6+ , O 8+ , etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

Science.gov (United States)

Alejo, A.; Kar, S.; Ahmed, H.; Krygier, A. G.; Doria, D.; Clarke, R.; Fernandez, J.; Freeman, R. R.; Fuchs, J.; Green, A.; Green, J. S.; Jung, D.; Kleinschmidt, A.; Lewis, C. L. S.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Nersisyan, G.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Ruiz, J. A.; Vassura, L.; Zepf, M.; Borghesi, M.

2014-09-01

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C6 +, O8 +, etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

Energy Technology Data Exchange (ETDEWEB)

Alejo, A.; Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.; Doria, D.; Green, A.; Jung, D.; Lewis, C. L. S.; Nersisyan, G. [Centre for Plasma Physics, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Krygier, A. G.; Freeman, R. R. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Clarke, R.; Green, J. S.; Notley, M. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Fernandez, J. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Instituto de Fusión Nuclear, Universidad Politécnica de Madrid, 28006 Madrid (Spain); Fuchs, J. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Kleinschmidt, A.; Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstrasse 9, D-64289 Darmstadt (Germany); Morrison, J. T. [Propulsion Systems Directorate, Air Force Research Lab, Wright Patterson Air Force Base, Ohio 45433 (United States); Najmudin, Z.; Nakamura, H. [Blackett Laboratory, Department of Physics, Imperial College, London SW7 2AZ (United Kingdom); and others

2014-09-15

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C{sup 6+}, O{sup 8+}, etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

First-principles thermal conductivity of warm-dense deuterium plasmas for inertial confinement fusion applications.

Science.gov (United States)

Hu, S X; Collins, L A; Boehly, T R; Kress, J D; Goncharov, V N; Skupsky, S

2014-04-01

Thermal conductivity (κ) of both the ablator materials and deuterium-tritium (DT) fuel plays an important role in understanding and designing inertial confinement fusion (ICF) implosions. The extensively used Spitzer model for thermal conduction in ideal plasmas breaks down for high-density, low-temperature shells that are compressed by shocks and spherical convergence in imploding targets. A variety of thermal-conductivity models have been proposed for ICF hydrodynamic simulations of such coupled and degenerate plasmas. The accuracy of these κ models for DT plasmas has recently been tested against first-principles calculations using the quantum molecular-dynamics (QMD) method; although mainly for high densities (ρ > 100 g/cm3), large discrepancies in κ have been identified for the peak-compression conditions in ICF. To cover the wide range of density-temperature conditions undergone by ICF imploding fuel shells, we have performed QMD calculations of κ for a variety of deuterium densities of ρ = 1.0 to 673.518 g/cm3, at temperatures varying from T = 5 × 103 K to T = 8 × 106 K. The resulting κQMD of deuterium is fitted with a polynomial function of the coupling and degeneracy parameters Γ and θ, which can then be used in hydrodynamic simulation codes. Compared with the "hybrid" Spitzer-Lee-More model currently adopted in our hydrocode lilac, the hydrosimulations using the fitted κQMD have shown up to ∼20% variations in predicting target performance for different ICF implosions on OMEGA and direct-drive-ignition designs for the National Ignition Facility (NIF). The lower the adiabat of an imploding shell, the more variations in predicting target performance using κQMD. Moreover, the use of κQMD also modifies the shock conditions and the density-temperature profiles of the imploding shell at early implosion stage, which predominantly affects the final target performance. This is in contrast to the previous speculation that κQMD changes mainly the

Peculiarities of using mixed deuterium and tritium ion beams of complicated atomic-molecular composition for fast neutron generation

International Nuclear Information System (INIS)

Kir'yanov, G.I.; Syromukov, S.V.

1983-01-01

The neutron yield is calculated depending on deuterium and tritium beam parameters as well as on the target parameters. Cases of target presaturation with hydrogen nuclides and of target stuffing with the ion beam in the process of the system functioning are discussed. It is shown that the neutron yield is approximately three times more in the case with a pure beam compared to the case with a niked beam

Electron scattering from high-momentum neutrons in deuterium

International Nuclear Information System (INIS)

Klimenko, A.V.; Kuhn, S.E.; Bueltmann, S.; Careccia, S.L.; Dharmawardane, K.V.; Dodge, G.E.; Guler, N.; Hyde-Wright, C.E.; Klein, A.; Tkachenko, S.; Weinstein, L.B.; Zhang, J.; Butuceanu, C.; Griffioen, K.A.; Baillie, N.; Fersch, R.G.; Funsten, H.; Egiyan, K.S.; Asryan, G.; Dashyan, N.B.

2006-01-01

We report results from an experiment measuring the semiinclusive reaction 2 H(e,e ' p s ) in which the proton p s is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CEBAF large acceptance spectrometer. A reduced cross section was extracted for different values of final state missing mass W*, backward proton momentum p → s , and momentum transfer Q 2 . The data are compared to a simple plane wave impulse approximation (PWIA) spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. Within the framework of the simple spectator model, a 'bound neutron structure function' F 2n eff was extracted as a function of W* and the scaling variable x* at extreme backward kinematics, where the effects of FSI appear to be smaller. For p s >0.4 GeV/c, where the neutron is far off-shell, the model overestimates the value of F 2n eff in the region of x* between 0.25 and 0.6. A dependence of the bound neutron structure function on the neutron's 'off-shell-ness' is one possible effect that can cause the observed deviation

Porcine aminopeptidase N mediated polarized infection by porcine epidemic diarrhea virus in target cells

Energy Technology Data Exchange (ETDEWEB)

Cong, Yingying; Li, Xiaoxue; Bai, Yunyun [College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030 (China); Lv, Xiaonan [College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030 (China); CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience & Technology of China, Beijing 100090 (China); Herrler, Georg [Institute for Virology, University of Veterinary Medicine, Hannover D-30559 (Germany); Enjuanes, Luis [Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Cantoblanco, Madrid (Spain); Zhou, Xingdong [College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030 (China); Qu, Bo [Faculty of Life Sciences, Northeast Agricultural University, Harbin 150030 (China); Meng, Fandan [Institute for Virology, University of Veterinary Medicine, Hannover D-30559 (Germany); Cong, Chengcheng [College Animal Husbandry and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110161 (China); Ren, Xiaofeng; Li, Guangxing [College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030 (China)

2015-04-15

Infection of polarized intestinal epithelial cells by porcine epidemic diarrhea virus (PEDV) was characterized. Indirect immunofluorescence assay, real-time PCR, and transmission electron microscopy confirmed PEDV can be successfully propagated in immortalized swine small intestine epithelial cells (IECs). Infection involved porcine aminpeptidase N (pAPN), a reported cellular receptor for PEDV, transient expression of pAPN and siRNA targeted pAPN increased and decreased the infectivity of PEDV in IECs, respectively. Subsequently, polarized entry into and release from both Vero E6 and IECs was analyzed. PEDV entry into polarized cells and pAPN grown on membrane inserts occurs via apical membrane. The progeny virus released into the medium was also quantified which demonstrated that PEDV is preferentially released from the apical membrane. Collectively, our data demonstrate that pAPN, the cellular receptor for PEDV, mediates polarized PEDV infection. These results imply the possibility that PEDV infection may proceed by lateral spread of virus in intestinal epithelial cells. - Highlights: • PEDV infection of polarized intestinal epithelial cells (IECs) was characterized. • Porcine aminpeptidase N (pAPN) facilitated PEDV infection in IECs. • PEDV entry into and release from polarized cell via its apical membrane. • PEDV infection may proceed by lateral spread of virus in IECs.

Porcine aminopeptidase N mediated polarized infection by porcine epidemic diarrhea virus in target cells

International Nuclear Information System (INIS)

Cong, Yingying; Li, Xiaoxue; Bai, Yunyun; Lv, Xiaonan; Herrler, Georg; Enjuanes, Luis; Zhou, Xingdong; Qu, Bo; Meng, Fandan; Cong, Chengcheng; Ren, Xiaofeng; Li, Guangxing

2015-01-01

Infection of polarized intestinal epithelial cells by porcine epidemic diarrhea virus (PEDV) was characterized. Indirect immunofluorescence assay, real-time PCR, and transmission electron microscopy confirmed PEDV can be successfully propagated in immortalized swine small intestine epithelial cells (IECs). Infection involved porcine aminpeptidase N (pAPN), a reported cellular receptor for PEDV, transient expression of pAPN and siRNA targeted pAPN increased and decreased the infectivity of PEDV in IECs, respectively. Subsequently, polarized entry into and release from both Vero E6 and IECs was analyzed. PEDV entry into polarized cells and pAPN grown on membrane inserts occurs via apical membrane. The progeny virus released into the medium was also quantified which demonstrated that PEDV is preferentially released from the apical membrane. Collectively, our data demonstrate that pAPN, the cellular receptor for PEDV, mediates polarized PEDV infection. These results imply the possibility that PEDV infection may proceed by lateral spread of virus in intestinal epithelial cells. - Highlights: • PEDV infection of polarized intestinal epithelial cells (IECs) was characterized. • Porcine aminpeptidase N (pAPN) facilitated PEDV infection in IECs. • PEDV entry into and release from polarized cell via its apical membrane. • PEDV infection may proceed by lateral spread of virus in IECs

Optimization of atomic beam sources for polarization experiments

Energy Technology Data Exchange (ETDEWEB)

Gaisser, Martin; Nass, Alexander; Stroeher, Hans [IKP, Forschungszentrum Juelich (Germany)

2013-07-01

For experiments with spin-polarized protons and neutrons a dense target is required. In current atomic beam sources an atomic hydrogen or deuterium beam is expanded through a cold nozzle and a system of sextupole magnets and RF-transition units selects a certain hyperfine state. The achievable flux seems to be limited to about 10{sup 17} particles per second with a high nuclear polarization. A lot of experimental and theoretical effort has been undertaken to understand all effects and to increase the flux. However, improvements have remained marginal. Now, a Monte Carlo simulation based on the DSMC part of the open source C++ library OpenFOAM is set up in order to get a better understanding of the flow and to optimize the various elements. It is intended to include important effects like deflection from magnetic fields, recombination on the walls and spin exchange collisions in the simulation and make quantitative predictions of changes in the experimental setup. The goal is to get a tool that helps to further increase the output of an atomic beam source. So far, a new binary collision model, magnetic fields, RF-transition units and a tool to measure the collision age are included. The next step will be to couple the whole simulation with an optimization algorithm implementing Adaptive Simulated Annealing (ASA) in order to automatically optimize the atomic beam source.

Implanted Deuterium Retention and Release in Carbon-Coated Beryllium

Science.gov (United States)

Anderl, R. A.; Longhurst, G. R.; Pawelko, R. J.; Oates, M. A.

1997-06-01

Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 Å. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 Å revealed that exposure to a temperature of 400°C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400°C and an incident deuterium flux of approximately 6 × 1019 D/m2-s), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples.

Cosmic Deuterium and Social Networking Software

Science.gov (United States)

Pasachoff, J. M.; Suer, T.-A.; Lubowich, D. A.; Glaisyer, T.

2006-08-01

For the education of newcomers to a scientific field and for the convenience of students and workers in the field, it is helpful to have all the basic scientific papers gathered. For the study of deuterium in the Universe, in 2004-5 we set up http://www.cosmicdeuterium.info with clickable links to all the historic and basic papers in the field and to many of the current papers. Cosmic deuterium is especially important because all deuterium in the Universe was formed in the epoch of nucleosynthesis in the first 1000 seconds after the Big Bang, so study of its relative abundance (D:H~1:100,000) gives us information about those first minutes of the Universe's life. Thus the understanding of cosmic deuterium is one of the pillars of modern cosmology, joining the cosmic expansion, the 3 degree cosmic background radiation, and the ripples in that background radiation. Studies of deuterium are also important for understanding Galactic chemical evolution, astrochemistry, interstellar processes, and planetary formation. Some papers had to be scanned while others are available at the Astrophysical Data System, adswww.harvard.edu, or to publishers' Websites. By 2006, social networking software (http:tinyurl.com/ zx5hk) had advanced with popular sites like facebook.com and MySpace.com; the Astrophysical Data System had even set up MyADS. Social tagging software sites like http://del.icio.us have made it easy to share sets of links to papers already available online. We have set up http://del.icio.us/deuterium to provide links to many of the papers on cosmicdeuterium.info, furthering previous del.icio.us work on /eclipses and /plutocharon. It is easy for the site owner to add links to a del.icio.us site; it takes merely clicking on a button on the browser screen once the site is opened and the desired link is viewed in a browser. Categorizing different topics by keywords allows subsets to be easily displayed. The opportunity to expose knowledge and build an ecosystem of web

Linearly polarized photons at ELSA

Energy Technology Data Exchange (ETDEWEB)

Eberhardt, Holger [Physikalisches Institut, Universitaet Bonn (Germany)

2009-07-01

To investigate the nucleon resonance regime in meson photoproduction, double polarization experiments are currently performed at the electron accelerator ELSA in Bonn. The experiments make use of a polarized target and circularly or linearly polarized photon beams. Linearly polarized photons are produced by coherent bremsstrahlung from an accurately aligned diamond crystal. The orientation of the crystal with respect to the electron beam is measured using the Stonehenge-Technique. Both, the energy of maximum polarization and the plane of polarization, can be deliberately chosen for the experiment. The linearly polarized beam provides the basis for the measurement of azimuthal beam asymmetries, such as {sigma} (unpolarized target) and G (polarized target). These observables are extracted in various single and multiple meson photoproduction channels.

Semi-inclusive DIS Experiments Using Transversely Polarized Targets in Hall-A: Current Results and Future Plans

Directory of Open Access Journals (Sweden)

Allada Kalyan

2012-12-01

Full Text Available Measurement of single (SSA and double spin asymmetries (DSA in semiinclusive DIS reactions using polarized targets provide a powerful method to probe transverse momentum dependent parton distribution functions (TMDs. In particular, the experimentally measured SSA on nucleon targets can help in extracting the transversity and Sivers distribution functions of u and d-quarks. Similarly, the measured DSA are sensitive to the quark spin-orbital correlations, and provide an access to the TMD parton distribution function (g1T. A recent experiment conducted in Hall-A Jefferson Lab using transversely polarized 3He provide first such measurements on “effective” neutron target. The measurement was performed using 5.9 GeV beam from CEBAF and measured the target SSA/DSA in the SIDIS reaction 3He↑(e, e′π±X. The kinematical range, x = 0.19 ~ 0.34, at Q2 = 1.77 ~ 2.73 (GeV/c2, was focused on the valence quark region. The results from this measurement along with our plans for future high precision measurements in Hall-A are presented.

Sputtering of solid deuterium by He-ions

DEFF Research Database (Denmark)

Schou, Jørgen; Stenum, B.; Pedrys, R.

2001-01-01

Sputtering of solid deuterium by bombardment of 3He+ and 4He+ ions was studied. Some features are similar to hydrogen ion bombardment of solid deuterium, but for the He-ions a significant contribution of elastic processes to the total yield can be identified. The thin-film enhancement is more pro...... pronounced than that for hydrogen projectiles in the same energy range....

Process for the production of high purity deuterium

International Nuclear Information System (INIS)

Arrathoon, R.

1977-01-01

A process for the electrolysis of heavy water which results in the production of high purity deuterium without periodic replenishment of the electrolyte with additional deuterated compounds is defined. Electrolysis is effected through the use of an inexpensive cation-action permselective membrane which is essentially a solid polymer electrolyte and which is capable of automatically separating the evolved deuterium and oxygen gas. This cation-active permselective membrane does not introduce any intrinsic impurities or tritium contamination in the generated deuterium gas, does not require periodic revitalization with deuterated compounds or other chemical compounds, and is characterized by an unusually high electrical efficiency

What should be measured in deuteron breakup with polarized proton target

International Nuclear Information System (INIS)

Strokovskij, E.A.

1995-01-01

At present, two different approaches are used for interpretation of inclusive data on deuteron breakup with emission of protons-fragments at zero degree by hadrons. According to one of them the observed characteristics of this reaction (cross sections, polarization observables) are determined by the reaction mechanism and the deuteron structure at short distances (in the commonly accepted sense) plays a minor role. According to the other approach it is the deuteron structure at short distances which determines the observed trend of the data. Neither of these approaches can describe the data even qualitatively in the whole investigated region of kinematical variables, having particular success for some narrow region corresponding to long distances. Installation of the polarized proton target at LHE (Laboratory of High Energies) JINR opens an opportunity to perform a rather simple experiment which could discriminate one of these completing approaches. The idea of this experiment is discussed in the present paper. Measurement of the observable suggested here is a particular example of a general problem of a search for spin correlations in inelastic reactions between particles separated well in 4-velocity or rapidity spaces. In our particular case correlations of spin degrees of freedom between particles, one of which is in the target fragmentation region and the other belongs to the projectile fragmentation region, are discussed. 10 refs., 1 fig

Chemical behavior of energetic deuterium implanted into silicon carbide

International Nuclear Information System (INIS)

Iguchi, Kazunari; Morimoto, Yasutomi; Shimada, Asako; Inuduka, Nobuo; Okuno, Kenji; Nakamura, Hirohumi; Nishi, Masataka

2000-01-01

Studies on chemical behavior of energetic deuterium (D) ions implanted into SiC were carried out by means of X-ray Photoelectron Spectroscopy (XPS) and Thermal Desorption Spectroscopy (TDS). From XPS results, it was suggested that the implanted D was attracted strongly to Si and/or C. From TDS results, two peaks corresponding to D 2 release appeared near 470 K (1st peak) and 1080 K (2nd peak). The activation energies for the two D 2 release processes were also determined. It was found from these experimental results that the 1st peak seemed to be attributed to deuterium that existed in interstitial. The 2nd peak was considered to be caused by deuterium trapped in lattice defects produced through deuterium ion implantation. (author)

Spin-polarized 3He nuclear targets and metastable 4He atoms by optical pumping with a tunable, Nd:YAP laser

International Nuclear Information System (INIS)

Bohler, C.L.; Schearer, L.D.; Leduc, M.; Nacher, P.J.; Zachorowski, L.; Milner, R.G.; McKeown, R.D.; Woodward, C.E.

1988-01-01

Several Nd:YAP lasers were constructed which could be broadly tuned in the 1083-nm region which includes the helium 2 3 S-2 3 P transition, using a Lyot filter and thin, uncoated etalons within the laser cavity. 1 W of power could be extracted at 1083 nm through a 1% transmitting output coupler. This laser beam was used to optically pump metastable 4 He and 3 He 2 3 S helium atoms in a weak discharge cell, spin polarizing the metastable ensemble. In a 3 He cell the polarization is transferred to the nuclear spin system. A 3 He target cell at 0.3 Torr was polarized to 52% in a few minutes. We describe the application of this system to the design of polarized targets for experiments in nuclear physics

Polarized neutron capture in polarized 59Co and 165Ho nuclei

International Nuclear Information System (INIS)

Bosman, J.J.

1976-01-01

Gamma spectroscopy on the reactions 59 Co(n,γ) 60 Co and 165 Ho(n,γ) 166 Ho with polarized neutrons and polarized targets enabled the assignment of spins to 36 levels in 60 Co and 15 levels in 166 Ho. Several of them had not been reported earlier. The techniques used to polarize neutron beams and targets and the gamma-spectroscopy are extensively discussed

Transverse polarization of Σ+(1189) in photoproduction on a hydrogen target in CLAS

Science.gov (United States)

Nepali, C. S.; Amaryan, M.; Adhikari, K. P.; Aghasyan, M.; Anefalos Pereira, S.; Baghdasaryan, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Cole, P. L.; Collins, P.; Contalbrigo, M.; Crede, V.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Doughty, D.; Dupre, R.; Alaoui, A. El; Fassi, L. El; Fedotov, G.; Fegan, S.; Fersch, R.; Fleming, J. A.; Gabrielyan, M. Y.; Gevorgyan, N.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Heddle, D.; Hicks, K.; Ho, D.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Kvaltine, N. D.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mayer, M.; McKinnon, B.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Munevar, E.; Munoz Camacho, C.; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Phelps, E.; Phillips, J. J.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tian, Ye; Tkachenko, S.; Torayev, B.; Vernarsky, B.; Vlassov, A. V.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Weinstein, L. B.; Weygand, D. P.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.

2013-04-01

Experimental results on the Σ+(1189) hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson Laboratory are presented. The Σ+(1189) was reconstructed in the exclusive reaction γ+p→KS0+Σ+(1189) via the Σ+→pπ0 decay mode. The KS0 was reconstructed in the invariant mass of two oppositely charged pions with the π0 identified in the missing mass of the detected pπ+π- final state. Experimental data were collected in the photon energy range Eγ=1.0-3.5 GeV (s range 1.66-2.73 GeV). We observe a large negative polarization of up to 95%. As the mechanism of transverse polarization of hyperons produced in unpolarized photoproduction experiments is still not well understood, these results will help to distinguish between different theoretical models on hyperon production and provide valuable information for the searches of missing baryon resonances.

Thermodynamic and electrical properties of laser-shocked liquid deuterium

Science.gov (United States)

He, Zhiyu; Jia, Guo; Zhang, Fan; Luo, Kui; Huang, Xiuguang; Shu, Hua; Fang, Zhiheng; Ye, Junjian; Xie, Zhiyong; Xia, Miao; Fu, Sizu

2018-01-01

Liquid deuterium at high pressure and temperature has been observed to undergo significant electronic structural changes. Reflectivity and temperature measurements of liquid deuterium up to around 70 GPa were obtained using a quartz standard. The observed specific heat of liquid deuterium approaches the Dulong-Petit limit above 1 eV. Discussions on specific heat indicate a molecular dissociation below 1 eV and fully dissociated above 1.5 eV. Also, the electrical conductivity of deuterium estimated from reflectivity reaches 1.3 × 105 (Ωṡm)-1, proving that deuterium in this condition is a conducting degenerate liquid metal and undergo an insulator-metal transition. The results from specific heat, carrier density and conductivity agreed well with each other, which might be a reinforcement of the insulator-metal transition and the molecular dissociation. In addition, a new correction method of reflectivity in temperature calculation was proposed to improve the accuracy of temperature results. A new "dynamic calibration" was introduced in this work to make the experiments simpler and more accurate.

ICRF heating and transport of deuterium-tritium plasmas in TFTR

International Nuclear Information System (INIS)

Rogers, J.H.; Schilling, G.; Stevens, J.E.; Taylor, G.; Wilson, J.R.; Bell, M.G.; Budny, R.V.; Bretz, N.L.; Darrow, D.; Fredrickson, E.

1995-02-01

This paper describes results of the first experiments utilizing high-power ion cyclotron range of frequency (ICRF) to heat deuterium-tritium (D-T) plasmas in reactor-relevant regimes on the Tokamak Fusion Test Reactor (TFTR). Results from these experiments have demonstrated efficient core, second harmonic, tritium beating of D-T supershot plasmas with tritium concentrations ranging from 6%-40%. Significant direct ion heating on the order of 60% of the input radio frequency (rf) power has been observed. The measured deposition profiles are in good agreement with two-dimensional modeling code predictions. Energy confinement in an rf-heated supershot is at least similar to that without rf, and possibly better in the electron channel. Efficient electron heating via mode conversion of fast waves to ion Bernstein waves (IBW) has been demonstrated in ohmic, deuterium-deuterium and DT-neutral beam injection plasmas with high concentrations of minority 3 He (n 3He /n e = 15% - 30%). By changing the 3 He concentration or the toroidal field strength, the location of the mode-conversion radius was varied. The power deposition profile measured with rf power modulation indicated that up to 70% of the power can be deposited on electrons at an off-axis position. Preliminary results with up to 4 MW coupled into the plasma by 90-degree phased antennas showed directional propagation of the mode-converted IBW. Analysis of heat wave propagation showed no strong inward thermal pinch in off-axis heating of an ohmically-heated target plasma in TFTR

Deuterium in New Zealand rivers and streams

International Nuclear Information System (INIS)

Stewart, M.K.; Cox, M.A.; James, M.R.; Lyon, G.

1983-07-01

Over 750 deuterium measurements on rivers and streams in New Zealand are reported. Monthly samples were collected for periods of several years from a number of representative rivers. These show irregular storm-to-storm as well as seasonal deuterium variations. The seasonal variations range from as low as 1 per mille for lake-fed rivers to 8-10 per mille for rivers with large spring snow-melt contributions. Variations in mean annual ΔD values are believed to reflect changes in climatic variables; the present data will be used to compare with future changes. The bulk of the data are single samples; these show a geographic variation related to the altitude, latitude and climatic character of the catchments, with the highest deuterium contents (ΔD = -20 per mille) occurring in the far north, and lowest contents (-80 per mille) in the inland Otago region. Regression equations derived for the ΔD dependence on altitude (h) and latitude (l), are ΔD = -0.0169 h - 30.2 and westerly influence. Eastern climatic zones have lower deuterium contents because of rainout effects on the axial ranges. Contours of constant

Effect of initial-state target polarization on the single ionization of helium by 1-keV electron impact

International Nuclear Information System (INIS)

Sun Shi-Yan; Ma Xiao-Yan; Li Xia; Miao Xiang-Yang; Jia Xiang-Fu

2012-01-01

We report new results of triple differential cross sections for the single ionization of helium by 1-KeV electron impact at the ejection energy of 10 eV. Investigations have been made for both the perpendicular plane and the plane perpendicular to the momentum transfer geometries. The present calculation is based on the three-Coulomb wave function. Here we have also incorporated the effect of target polarization in the initial state. A comparison is made between the present calculation with the results of other theoretical methods and a recent experiment [Dürr M, Dimopoulou C, Najjari B, Dorn A, Bartschat K, Bray I, Fursa D V, Chen Z, Madison D H and Ullrich J 2008 Phys. Rev. A 77 032717]. At an impact energy of 1 KeV, the target polarization is found to induce a substantial change of the cross section for the ionization process. We observe that the effect of target polarization plays a dominant role in deciding the shape of triple differential cross sections. (atomic and molecular physics)

Deuterium gas-driven permeation and subsequent retention in rolled tungsten foils

International Nuclear Information System (INIS)

Liu, Feng; Zhou, Haishan; Li, Xiao-Chun; Xu, Yuping; An, Zhongqing; Mao, Hongmin; Xing, Wenjing; Hou, Qing; Luo, Guang-Nan

2014-01-01

Experiments concerning deuterium gas-driven permeation through rolled tungsten foils in the temperature range of 850–950 K and subsequent deuterium retention have been performed. The steady state permeation flux of deuterium is proportional to the square root of the driving pressure. The permeability of deuterium is in an order of 10 −14 mol m −1 s −1 Pa −1/2 in this temperature range and the activation energy for permeation is 1.21 eV. Measurements of diffusivity are significantly affected by the driving pressure, which can be well explained by a saturable-trap model. Thermal desorption spectra of samples feature a single deuterium release peak at about 873 K. TMAP 4 modeling of this peak gives a detrapping energy of 1.70 eV, which fits the dissociation enthalpy of deuterium desorbing from the inner wall of vacancy clusters or pores in tungsten

Deuterium gas-driven permeation and subsequent retention in rolled tungsten foils

Science.gov (United States)

Liu, Feng; Zhou, Haishan; Li, Xiao-Chun; Xu, Yuping; An, Zhongqing; Mao, Hongmin; Xing, Wenjing; Hou, Qing; Luo, Guang-Nan

2014-12-01

Experiments concerning deuterium gas-driven permeation through rolled tungsten foils in the temperature range of 850-950 K and subsequent deuterium retention have been performed. The steady state permeation flux of deuterium is proportional to the square root of the driving pressure. The permeability of deuterium is in an order of 10-14 mol m-1 s-1 Pa-1/2 in this temperature range and the activation energy for permeation is 1.21 eV. Measurements of diffusivity are significantly affected by the driving pressure, which can be well explained by a saturable-trap model. Thermal desorption spectra of samples feature a single deuterium release peak at about 873 K. TMAP 4 modeling of this peak gives a detrapping energy of 1.70 eV, which fits the dissociation enthalpy of deuterium desorbing from the inner wall of vacancy clusters or pores in tungsten.

Phenomenological nuclear reaction description in deuterium-saturated palladium and synthesized structure in dense deuterium gas under γ-quanta irradiation

International Nuclear Information System (INIS)

Didyk, A.Yu.; Wisniewski, R.

2012-01-01

The observed phenomena on the changes of chemical compositions in our previous reports allowed us to develop a phenomenological nuclear fusion-fission model with taking into consideration the elastic and inelastic scattering of photoprotons and photoneutrons, heating of surrounding deuterium nuclei, following D-D fusion reactions and fission of middle-mass nuclei by 'hot' protons, deuterons and various-energy neutrons. Such chain processes could produce the necessary number of neutrons, 'hot' deuterons for explanation of the observed experimental results. The developed approach can be a basis for creation of deuterated nuclear fission reactors (DNFR) with high-density deuterium gas and so-called deuterated metals. Also, the developed approach can be used for the study of nuclear reactions in high-density deuterium or tritium gases and deuterated metals

Some methods for labelling organic compounds by deuterium

International Nuclear Information System (INIS)

Moustapha, C.

1988-01-01

The rapid growth of knowledge in the fields of biochemistry, physiology, and molecular biology reflects to a considerable degree the utilization of stable isotopes (specially deuterium) in the study of chemical reactions and fragmentation mechanisms in mass spectrometry, as well as in the pharmacological and biological studies. Organic compounds maybe labelled by deuterium through classic organic reactions by using special deuterated solvents and reagents. This article discusses some reactions, with examples on how to prepare labelled compounds with high isotopic purety. These reactions are: exchange reactions in acid and alkaline media (the exchange in the chromatographic column in liquid and gas phases, the exchange in homogenous medium), reduction reactions of functional groups as well as saturation of the double bounds by deuterium using hydrogenation catalystes, electrochemical reactions using KOLBE, and photochemical reactions. This article also deals with spectroscopic properties of deuterium and the methods which are used to identify its compounds such as infrared, nuclear magnetic resonance, and mass spectroscopy. 37 refs., 2 figs

Implanted deuterium retention and release in carbon-coated beryllium

International Nuclear Information System (INIS)

Anderl, R.A.; Longhurst, G.R.; Pawelko, R.J.; Oates, M.A.

1997-01-01

Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 angstrom. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 angstrom revealed that exposure to a temperature of 400 degrees C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400 degrees C and an incident deuterium flux of approximately 6 X 10 19 D/m 2 sec), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples. 4 refs., 8 figs., 1 tab

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

Optimization of atomic beam sources for polarization experiments

Energy Technology Data Exchange (ETDEWEB)

Gaisser, Martin; Nass, Alexander; Stroeher, Hans [IKP, Forschungszentrum Juelich (Germany)

2012-07-01

For experiments with spinpolarized protons and neutrons a dense target is required. In current atomic beam sources an atomic hydrogen or deuterium beam is expanded through a cold nozzle and a system of sextupole magnets and RF-transition units selects a certain hyperfine state. The achievable flux seems to be limited to about 10{sup 17} particles per second with a high nuclear polarization. A lot of experimental and theoretical effort has been undertaken to understand all effects and to increase the flux. However, improvements have remained marginal. Now, a Monte Carlo simulation based on the DSMC part of the open source C++ library OpenFOAM is set up in order to get a better understanding of the flow and to optimize the various elements. The goal is to include important effects like deflection from a magnetic field, recombination on the walls and spin exchange collisions in the simulation and make quantitative predictions of changes in the experimental setup. The goal is to get a tool that helps to further increase the output of an atomic beam source.

Deuterium exchange between liquid water and gaseous hydrogen

International Nuclear Information System (INIS)

Dave, S.M.; Ghosh, S.K.; Sadhukhan, H.K.

1982-01-01

The overall separation factors for the deuterium exchange between liquid water and gaseous hydrogen have been calculated over a wide range of temperature, pressure and deuterium concentrations. These data would be useful in the design and other considerations for heavy water production, based on hydrogen-water exchange. (author)

Measuring the hydrogen/deuterium exchange of proteins at high spatial resolution by mass spectrometry: overcoming gas-phase hydrogen/deuterium scrambling.

Science.gov (United States)

Rand, Kasper D; Zehl, Martin; Jørgensen, Thomas J D

2014-10-21

Proteins are dynamic molecules that exhibit conformational flexibility to function properly. Well-known examples of this are allosteric regulation of protein activity and ligand-induced conformational changes in protein receptors. Detailed knowledge of the conformational properties of proteins is therefore pertinent to both basic and applied research, including drug development, since the majority of drugs target protein receptors and a growing number of drugs introduced to the market are therapeutic peptides or proteins. X-ray crystallography provides a static picture at atomic resolution of the lowest-energy structure of the native ensemble. There is a growing need for sensitive analytical tools to explore all of the significant molecular structures in the conformational landscape of proteins. Hydrogen/deuterium exchange monitored by mass spectrometry (HDX-MS) has recently emerged as a powerful method for characterizing protein conformational dynamics. The basis of this method is the fact that backbone amides in stable hydrogen-bonded structures (e.g., α-helices and β-sheets) are protected against exchange with the aqueous solvent. All protein structures are dynamic, however, and eventually all of the protecting hydrogen bonds will transiently break as the protein--according to thermodynamic principles--cycles through partially unfolded states that correspond to excited free energy levels. As a result, all of the backbone amides will eventually become temporarily solvent-exposed and exchange-competent over time. Consequently, a folded protein in D2O will gradually incorporate deuterium into its backbone amides, and the kinetics of the process can be readily monitored by mass spectrometry. The deuterium uptake kinetics for the intact protein (global exchange kinetics) represents the sum of the exchange kinetics for the individual backbone amides. Local exchange kinetics is typically achieved by using pepsin digestion under quench conditions (i.e., under cold

Pneumatic injector of deuterium macroparticles for TORE-SUPRA tokamak

International Nuclear Information System (INIS)

Vinyar, I.V.; Umov, A.P.; Lukin, A.Ya.; Skoblikov, S.V.; Reznichenko, P.V.; Krasil'nikov, I.A.

2006-01-01

The pneumatic injector for periodic injection of fuel-solid-deuterium pellets into the plasma of the TORE-SUPRA tokamak in a steady-state mode is described. The deuterium pellet injection with an unlimited duration is ensured by a screw extruder in which gaseous deuterium is frozen and squeezed outwards in the form of a rod with a rectangular cross section. A cutter installed on the injector's barrel cuts a cylinder with a diameter of 2 mm and a length of 1.0-3.5 mm out from this rod. The movement of the cutter is controlled by a pulsed electromagnetic drive at a pulse repetition rate of 10 Hz. In the injector's barrel, a compressed gas accelerates a deuterium pellet to a velocity of 100-650 m/s [ru

The scattering of polarized neutrons from statically polarized solid {sup 3}He

Energy Technology Data Exchange (ETDEWEB)

Haase, D.G.; Keith, C.D.; Gould, C.R.; Seely, M.L. [North Carolina State Univ., Raleigh, NC (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Huffman, P.R.; Roberson, N.R.; Tornow, W.; Wilburn, W.S. [Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)]|[Duke University, Durham, NC 27708-0308 (United States)

1998-01-11

We have constructed a 0.4 mole solid {sup 3}He target, cryogenically polarized at 12 mK in a field of 7 T. The 0.04 atoms/b target reached a polarization of 38% in 35 h. Such a target may be applied to any experiment which is tolerant of the large ambient magnetic field and which produces target heating of less than a microwatt. High energy neutron and photon scattering experiments meet these requirements. The target`s figure of merit for neutron transmission measurement exceeds that of polarized gas targets by greater than 35. At the Triangle Universities Nuclear Laboratory we have used the target to measure the total cross section differences {Delta}{sigma}{sub T} and {Delta}{sigma}{sub L} for incident polarized neutrons of energies 2-8 MeV. The cross section difference is sensitive to the excited state structure of the n-{sup 3}He system. The results have been compared to a recent R-matrix analysis of A=4 scattering and reaction data, and provide support for the {sup 4}He level scheme derived from that analysis. (orig.). 11 refs.

Synthesis of deuterium-labelled viloxazine. [Antidepressant

Energy Technology Data Exchange (ETDEWEB)

Mamada, Kumiko; Furuta, Takashi; Kasuya, Yasuji

1988-06-01

The synthesis of deuterium-labelled viloxazine with high isotopic purity is described. The synthetic procedures employ alkylation of 2-(benzyloxy)phenol with (/sup 2/H/sub 5/)ethyl iodide for the introduction of deuterium. Catalytic removal of the benzyl group of the deuterated product followed by reaction with epichlorohydrin afforded 1,2-epoxy-3-(2'-pentadeuteroethoxy-phenoxy)propane. Addition of 2-aminoethyl hydrogen sulphate to the epoxide and subsequent ring formation into a morpholine derivative produced the desired (/sup 2/H/sub 5/)viloxazine.

Continuum emission from irradiated solid deuterium

DEFF Research Database (Denmark)

Forrest, J.A.; Brooks, R.L.; Hunt, J.L.

1992-01-01

A new emission feature from the spectrum of irradiated solid deuterium has been observed in the very near-infrared spectral region. Experiments from three laboratories, using different excitation conditions, have confirmed the observation. Comparison of the timing and temperature dependence...... of the spectral feature to the information previously available from electron spin resonance studies of solid deuterium, points to atomic association as the underlying cause. We shall show the connection of this emission to the occurrence of thermal spikes and optical flashes, previously observed in solid...

Deuterium gas-driven permeation and subsequent retention in rolled tungsten foils

Energy Technology Data Exchange (ETDEWEB)

Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhou, Haishan [Department of Fusion Science, The Graduate University for Advanced Studies, Toki 509-5292 (Japan); Li, Xiao-Chun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Xu, Yuping; An, Zhongqing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China); Mao, Hongmin; Xing, Wenjing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Hou, Qing [Key Laboratory for Radiation Physics and Technology, Sichuan University, Chengdu 610061 (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China)

2014-12-15

Experiments concerning deuterium gas-driven permeation through rolled tungsten foils in the temperature range of 850–950 K and subsequent deuterium retention have been performed. The steady state permeation flux of deuterium is proportional to the square root of the driving pressure. The permeability of deuterium is in an order of 10{sup −14} mol m{sup −1} s{sup −1} Pa{sup −1/2} in this temperature range and the activation energy for permeation is 1.21 eV. Measurements of diffusivity are significantly affected by the driving pressure, which can be well explained by a saturable-trap model. Thermal desorption spectra of samples feature a single deuterium release peak at about 873 K. TMAP 4 modeling of this peak gives a detrapping energy of 1.70 eV, which fits the dissociation enthalpy of deuterium desorbing from the inner wall of vacancy clusters or pores in tungsten.

NMR dispersion measurement of dynamic nuclear polarization

International Nuclear Information System (INIS)

Davies, K.; Cox, S.F.J.

1978-01-01

The feasibility of monitoring dynamic nuclear polarization from the NMR dispersive susceptibility is examined. Two prototype instruments are tested in a polarized proton target using organic target material. The more promising employs a tunnel diode oscillator, inside the target cavity, and should provide a precise polarization measurement working at a frequency far enough from the main resonance for the disturbance of the measured polarization to be negligible. Other existing methods for measuring target polarization are briefly reviewed. (author)

Sources of polarized neutrons

International Nuclear Information System (INIS)

Walter, L.

1983-01-01

Various sources of polarized neutrons are reviewed. Monoenergetic source produced with unpolarized or polarized beams, white sources of polarized neutrons, production by transmissions through polarized hydrogen targets and polarized thermal neutronsare discussed, with appropriate applications included. (U.K.)

One-hadron transverse spin effects on a proton target at COMPASS

Energy Technology Data Exchange (ETDEWEB)

Adolph, Christoph

2013-02-19

distribution functions, the aforementioned transversity and Sivers functions, the worm-gear 2 function and the Pretzelosity function. The other four are of subleading order. The investigation of the structure of the nucleon spin is one of the main goals of the COMPASS experiment at CERN. For the measurement of transverse spin effects a 160 GeV/c polarized μ{sup +} beam is scattered off a polarized nucleon target. In the years 2002-2004 a deuterium ({sup 6}LiD) target was used, while in 2007 and 2010 the measurement was done on a proton (NH{sub 3}) target. In this thesis the methods of analysis and the results for the eight transverse spin dependent distribution functions from the 2010 data-taking period will be shown for unidentified hadrons as well as for identified pions and kaons. Furthermore the Collins and Sivers asymmetries for the production of K{sup 0} are presented. The work is concluded by a comparison of the measured asymmetries with the results of the HERMES experiment at DESY and existing model predictions. A short interpretation of the results for the Collins and Sivers asymmetries is also given.

Deuterium in the water cycle of the Schirmacher Oasis (Dronning Maud Land, East Antarctica). A data compilation

International Nuclear Information System (INIS)

Kowski, P.; Richter, W.

1988-01-01

The Schirmacher Oasis (Dronning Maud Land) - one of the rock deserts of the South Polar region - is situated on the coast of the Antarctic continent, between inland and shelf ice. The data compilation contains results of deuterium studies from different parts of the local water cycle and is arranged according to the main parts: precipitation and atmospheric moisture, both collected near Novolazarevskaya Station, lake water, surface snow and ice, shallow drill cores of snow and ice, and from melt water runoff. Finally, monthly means of precipitation and atmospheric moisture are given. (author)

Neutron penumbral imaging of laser-fusion targets

International Nuclear Information System (INIS)

Lerche, R.A.; Ress, D.B.

1988-01-01

Using a new technique, penumbral coded-aperture imaging, the first neutron images of laser-driven, inertial-confinement fusion targets were obtained. With these images the deuterium-tritium burn region within a compressed target can be measured directly. 4 references, 11 figures

Deuterium electrodisintegration at high recoil momentum

International Nuclear Information System (INIS)

Steenholen, G.

1996-01-01

The availability of continuous electron beams made it possible to carry out various deuterium electro-disintegration experiments in kinematical domains corresponding to a high recoil momentum. Three such experiments are discussed: 1) the left-right asymmetry with respect to the direction of the momentum transfer has been measured with good precision; 2) cross sections have been obtained in a kinematical region well above the quasi-elastic peak; 3) data have been taken in quasi-elastic kinematics that can be used to study high-momentum components in the deuterium wave function [ru

Experimental Determination of the Possible Deuterium - Deuterium Fusion Reaction Originated in a Single Cavitation Bubble Luminescence System Using CDCL3 and D2 O

International Nuclear Information System (INIS)

Barbaglia, Mario; Florido, Pablo; Mayer, Roberto; Bonetto, Fabian

2003-01-01

We focus this work on the measurement of the possible Deuterium - Deuterium reaction in a SCBL (Single Cavitation Bubble Luminescence) system.We measure the possible reaction at the bubble generation time and at the bubble collapse time. We use a Nd:YAG laser and CDCl 3 and D 2 O as a medium to generate the bubble. Since CDCl 3 accommodation coefficient is best than that of D 2 O, it is expected a greater collapse force than using D 2 O.To benefit the bubble collapse violence, we diminish the temperature of the liquids.To avoid false neutron detection, we developed a measuring system with high background reject using the characteristic experiment times.No neutrons attributable to Deuterium - Deuterium fusion reaction were measured

Real-time multi-target ranging based on chaotic polarization laser radars in the drive-response VCSELs.

Science.gov (United States)

Zhong, Dongzhou; Xu, Geliang; Luo, Wei; Xiao, Zhenzhen

2017-09-04

According to the principle of complete chaos synchronization and the theory of Hilbert phase transformation, we propose a novel real-time multi-target ranging scheme by using chaotic polarization laser radar in the drive-response vertical-cavity surface-emitting lasers (VCSELs). In the scheme, to ensure each polarization component (PC) of the master VCSEL (MVCSEL) to be synchronized steadily with that of the slave VCSEL, the output x-PC and y-PC from the MVCSEL in the drive system and those in the response system are modulated by the linear electro-optic effect simultaneously. Under this condition, by simulating the influences of some key parameters of the system on the synchronization quality and the relative errors of the two-target ranging, related operating parameters can be optimized. The x-PC and the y-PC, as two chaotic radar sources, are used to implement the real-time ranging for two targets. It is found that the measured distances of the two targets at arbitrary position exhibit strong real-time stability and only slight jitter. Their resolutions are up to millimeters, and their relative errors are very small and less than 2.7%.

Deuterium in atmospheric cycle

International Nuclear Information System (INIS)

Pontikis, M.C.

Interest of the study concerning the deuterium content variation (HDO) in the atmospheric water. Standards and measurement methods. Molecule HDO cycle in the atmospheric water. Application to the study of hail-generating cumulus-nimbus and of the mantle of snow [fr

Deuterium trapping in ion implanted and co-deposited beryllium oxide layers

International Nuclear Information System (INIS)

Markin, A.V.; Gorodetsky, A.E.; Zakharov, A.P.; Wu, C.H.

2000-01-01

Deuterium trapping in beryllium oxide films irradiated with 400 eV D ions has been studied by thermal desorption spectroscopy (TDS). It has been found that for thermally grown BeO films implanted in the range 300 - 900 K the total deuterium retention doesn't depend whereas TDS spectra do markedly on irradiation temperature. For R.T. implantation the deuterium is released in a wide range from 500 to 1100 K. At implantation above 600 K the main portion of retained deuterium is released in a single peak centered at about 1000 K. The similar TDS peak is measured for D/BeO co-deposited layer. In addition we correlate our implantation data on BeO with the relevant data on beryllium metal and carbon. The interrelations between deuterium retention and microstructure are discussed. (orig.)

The movable polarized target as a basic equipment for high energy spin physics experiments at the JINR-Dubna accelerator complex

Energy Technology Data Exchange (ETDEWEB)

Lehar, F.; Adiasevich, B.; Androsov, V.P.; Angelov, N.; Anischenko, N.; Antonenko, V.; Ball, J.; Baryshevsky, V.G.; Bazhanov, N.A.; Belyaev, A.A.; Benda, B.; Bodyagin, V.; Borisov, N.; Borzunov, Yu.; Bradamante, F.; Bunyatova, E.; Burinov, V.; Chernykh, E.; Combet, M.; Datskov, A.; Durand, G.; Dzyubak, A.P.; Fontaine, J.M.; Get`man, V.A.; Giorgi, M.; Golovanov, L.; Grebenyuk, V.; Grosnick, D.; Gurevich, G.; Hasegawa, T.; Hill, D.; Horikawa, N.; Igo, G.; Janout, Z.; Kalinnikov, V.A.; Karnaukhov, I.M.; Kasprzyk, T.; Khachaturov, B.A.; Kirillov, A.; Kisselev, Yu.; Kousmine, E.S.; Kovalenko, A.; Kovaljov, A.I.; Ladygin, V.P.; Lazarev, A.; Leconte, P.; Lesquen, A. de; Lukhanin, A.A.; Mango, S.; Martin, A.; Matafonov, V.N.; Matyushevsky, E.; Mironov, S.; Neganov, A.B.; Neganov, B.S.; Nomofilov, A.; Perelygin, V.; Plis, Yu.; Pilipenko, Yu.; Pisarev, I.L.; Piskunov, N.; Polunin, Yu.; Popkov, Yu.P.; Propov, A.A.; Prokofiev, A.N.; Rekalo, M.P.; Rukoyatkin, P.; Sans, J.L.; Sapozhnikov, M.G.; Sharov, V.; Shilov, S.; Shishov, Yu.; Sitnik, I.M.; Sorokin, P.V.; Spinka, H.; Sporov, E.A.; Strunov, L.N.; Svetov, A.; De Swart, J.J.; Telegin, Yu.P.; Tolmashov, I.; Trentalange, S.; Tsvinev, A.; Usov, Yu.A.; Vikhrov, V.V.; Whitten, C.A.; Zaporozhets, S.; Zarubin, A.; Zhdanov, A.A.; Zolin, L. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de Physique des Particules, de Physique Nucleaire et de l`Instrumentation Associee]|[I.V. Kurchatov Inst. of Atomic Energy, Moscow (Russian Federation)]|[Kharkov Inst. of Physics and Technology (Russian Federation)]|[Lab. of Nuclear Problems, JINR, Dubna (Russian Federation)]|[Lab. of High Energy Physics, JINR, Dubna (Russian Federation)]|[Lab. National SATURNE, CNRS, 91 - Gif-sur-Yvette (France)]|[Inst. of Physics, Belarus Academy of Sciences, Minsk (Belarus)]|[Dept. of Physics, Petersburg Nuclear Physics Inst., Gatchina (Russian Federation)

1995-03-01

A movable polarized proton target is planned to be installed in polarized beams of the Synchrophasotron-Nuclotron complex in order to carry out a spin physics experimental program at Dubna. The project is described and the first proposed experiments are discussed. ((orig.))

The movable polarized target as a basic equipment for high energy spin physics experiments at the JINR-Dubna accelerator complex

International Nuclear Information System (INIS)

Lehar, F.; Adiasevich, B.; Androsov, V.P.; Angelov, N.; Anischenko, N.; Antonenko, V.; Ball, J.; Baryshevsky, V.G.; Bazhanov, N.A.; Belyaev, A.A.; Benda, B.; Bodyagin, V.; Borisov, N.; Borzunov, Yu.; Bradamante, F.; Bunyatova, E.; Burinov, V.; Chernykh, E.; Combet, M.; Datskov, A.; Durand, G.; Dzyubak, A.P.; Fontaine, J.M.; Get'man, V.A.; Giorgi, M.; Golovanov, L.; Grebenyuk, V.; Grosnick, D.; Gurevich, G.; Hasegawa, T.; Hill, D.; Horikawa, N.; Igo, G.; Janout, Z.; Kalinnikov, V.A.; Karnaukhov, I.M.; Kasprzyk, T.; Khachaturov, B.A.; Kirillov, A.; Kisselev, Yu.; Kousmine, E.S.; Kovalenko, A.; Kovaljov, A.I.; Ladygin, V.P.; Lazarev, A.; Leconte, P.; Lesquen, A. de; Lukhanin, A.A.; Mango, S.; Martin, A.; Matafonov, V.N.; Matyushevsky, E.; Mironov, S.; Neganov, A.B.; Neganov, B.S.; Nomofilov, A.; Perelygin, V.; Plis, Yu.; Pilipenko, Yu.; Pisarev, I.L.; Piskunov, N.; Polunin, Yu.; Popkov, Yu.P.; Propov, A.A.; Prokofiev, A.N.; Rekalo, M.P.; Rukoyatkin, P.; Sans, J.L.; Sapozhnikov, M.G.; Sharov, V.; Shilov, S.; Shishov, Yu.; Sitnik, I.M.; Sorokin, P.V.; Spinka, H.; Sporov, E.A.; Strunov, L.N.; Svetov, A.; De Swart, J.J.; Telegin, Yu.P.; Tolmashov, I.; Trentalange, S.; Tsvinev, A.; Usov, Yu.A.; Vikhrov, V.V.; Whitten, C.A.; Zaporozhets, S.; Zarubin, A.; Zhdanov, A.A.; Zolin, L.

1995-01-01

A movable polarized proton target is planned to be installed in polarized beams of the Synchrophasotron-Nuclotron complex in order to carry out a spin physics experimental program at Dubna. The project is described and the first proposed experiments are discussed. ((orig.))

Trapping behaviour of deuterium ions implanted into tungsten simultaneously with carbon ions

International Nuclear Information System (INIS)

Kobayashi, Makoto; Suzuki, Sachiko; Wang, Wanjing; Kurata, Rie; Kida, Katsuya; Oya, Yasuhisa; Okuno, Kenji; Ashikawa, Naoko; Sagara, Akio; Yoshida, Naoaki

2009-01-01

The trapping behaviour of deuterium ions implanted into tungsten simultaneously with carbon ions was investigated by thermal desorption spectroscopy (TDS) and x-ray photoelectron spectroscopy (XPS). The D 2 TDS spectrum consisted of three desorption stages, namely desorption of deuterium trapped by intrinsic defects, ion-induced defects and carbon with the formation of the C-D bond. Although the deuterium retention trapped by intrinsic defects was almost constant, that by ion-induced defects increased as the ion fluence increased. The retention of deuterium with the formation of the C-D bond was saturated at an ion fluence of 0.5x10 22 D + m -2 , where the major process was changed from the sputtering of tungsten with the formation of a W-C mixture to the formation of a C-C layer, and deuterium retention as the C-D bond decreased. It was concluded that the C-C layer would enhance the chemical sputtering of carbon with deuterium with the formation of CD x and the chemical state of carbon would control the deuterium retention in tungsten under C + -D 2 + implantation.

A study of inclusive charged current neutrino interactions in deuterium

International Nuclear Information System (INIS)

Visser, C.P.

1986-01-01

In this thesis the results of an analysis of inclusive neutrino and antineutrino interaction on deuterium nuclei are presented. The use of deuterium as a target provides a mean to study proton and neutron scattering separately. The presently accepted theory of electro-weak interactions is reviewed. Applications of the quark-parton model in the context of deep-inelastic neutrino interactions on nucleons are summarized. The concept of scaling and its consequences are treated, together with some sources of violation of scaling. The properties of the CERN wide-band neutrino beam and an overview of the elements of this beam are given. The method to determine the energy distribution and the composition of the neutrino and antineutrino beam is described. The technique employed to separate neutrino interactions on protons and neutrons is discussed. Results of the measurement of the total nucleon charged-current cross-sections and differential cross-sections are presented. The relative contributions of quarks and antiquarks to the neutrino cross-sections are deduced from y-distributions and compared to those obtained from the total cross-section measurements. Finally, the analysis of the structure functions is given. (Auth.)

Thermal desorption of deuterium from Be, and Be with helium bubbles

Energy Technology Data Exchange (ETDEWEB)

Fedorov, A.V.; Van Veen, A.; Busker, G.J. [Delft Univ. of Technology (Netherlands). Interfaculty Reactor Inst.

1998-01-01

Deuterium desorption measurements carried out on a single-crystalline beryllium sample are presented. Deuterium ions were implanted at room temperature at the energy of 0.7 and 1.2 keV up to doses ranging from 10{sup 19} to 3.6 x 10{sup 21} m{sup -2}. In order to eliminate the influence of the beryllium-oxide surface layer, before the implantation the surface of the sample was cleaned by argon sputtering. After the implantation the sample was annealed up to 1200 K at a constant rate of 10 K/s. Deuterium released from the sample was monitored by a calibrated quadrupole mass-spectrometer. The desorption spectra revealed two different contributions. One is a well defined and very narrow peak centered around 450 K. This peak is observed only at high implantation doses > 7.8 x 10{sup 20} m{sup -2}, which is close to the deuterium saturation limit of 0.3 D/Be and is related to deuterium release from blisters or interconnected bubbles. The activation energy of 1.1 eV and the threshold implantation dose are consistent with the values reported in literature. The second contribution in the release spectra is found in the temperature range from 600 to 900 K and is present throughout the whole range of the implantation doses. The activation energies corresponding to this release lie in the range between 1.8 and 2.5 eV and are ascribed to the release from deuterium-vacancy type of defects. In a number of experiments the deuterium implantation was preceded by helium implantation followed by partial annealing to create helium bubbles. The resulting deuterium desorption spectra indicate that deuterium detrapping from helium bubbles is characterized by an activation energy of 2.7 eV. (author)

Electronic device for measuring the polarization parameter in the π-p → π0n charge exchange reaction on a polarized proton target

International Nuclear Information System (INIS)

Brehin, S.

1967-12-01

An electronic apparatus has been constructed to measure the polarization parameter P 0 (t) in π - p → π 0 n charge exchange scattering at 5.9 GeV/c and 11,2 GeV/c on polarized proton target. This device insures triggering of a heavy plate spark chamber, allowing visualisation of γ rays from the π 0 decays when the associated neutron offers suitable characteristics in direction and energy. The neutron is detected by an array of 32 counters and his energy is measured by a time of flight method. Electronic circuits of this apparatus are described as test and calibration methods used. (author) [fr

A study of the internal spin structure of the proton through inclusive and semi-inclusive polarized deep-inelastic muon-proton scattering

International Nuclear Information System (INIS)

Papavassiliou, V.

1988-01-01

The internal spin structure of the proton was studied in a deep-inelastic scattering experiment a CERN, the European Laboratory for Nuclear Research, by the European Muon Collaboration, using a longitudinally polarized muon beam and a longitudinally polarized target at irradiated ammonia. The spin asymmetry was studied as a function of the Bjorken scaling variable x and the results were in agreement over the region of overlap with previous experiments that used lower-energy polarized electron beams. The higher energies of the experiment allowed to study with precision the previously unexplored region of x below 0.1 and to compute the integral of the spin-dependent structure function g 1 of the proton. This integral was found to be in disagreement with the Ellis-Jaffe sum rule which could imply either a breakdown of the SU(3) symmetry in the decays of the members of the baryon octet or a significant polarization of the strange-quark sea of the proton opposite to the proton spin. In either case and assuming the validity of the Bjorken sum rule that relates the integrals of the spin-dependent structure functions of the proton and the neutron, the total helicity of all the quarks is found to account for only a small fraction of the proton helicity. In addition, spin asymmetries in the semi-inclusive reactions where a hadron of definite sign is observed in the final state were studied. The results are consistent with the down quarks being polarized opposite to the proton spin, as expected by symmetry arguments. Implication of the results on different areas in particle physics are presented. Some future prospects for spin physics are discussed and predictions are given for deep-inelastic-scattering experiments on polarized deuterium targets and the spin structure of the neutron

Neutrino disintegration of deuterium

International Nuclear Information System (INIS)

Ying, S.; Haxton, W.; Henley, E.M.

1989-01-01

We calculate the rate of both neutral- and charged-current neutrino and antineutrino disintegration of deuterium. These rates are of interest for solar 8 B and hep ( 3 He + p) spectra and supernovae neutrinos, and are relevant for the Sudbury Neutrino Observatory (SNO)

Bounds on Time Reversal Violation From Polarized Neutron Capture With Unpolarized Targets.

Science.gov (United States)

Davis, E D; Gould, C R; Mitchell, G E; Sharapov, E I

2005-01-01

We have analyzed constraints on parity-odd time-reversal noninvariant interactions derived from measurements of the energy dependence of parity-violating polarized neutron capture on unpolarized targets. As previous authors found, a perturbation in energy dependence due to a parity (P)-odd time (T)-odd interaction is present. However, the perturbation competes with T-even terms which can obscure the T-odd signature. We estimate the magnitudes of these competing terms and suggest strategies for a practicable experiment.

Horizontal cryostat for polarized proton targets; Cryostat horizontal pour cibles de protons polarises

Energy Technology Data Exchange (ETDEWEB)

Roubeau, P M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-11-15

Continuously fed horizontal cryostat to be used for polarized proton targets; includes: 1 standard storage dewar commercially available; 2 shifting of dewar requiring 10 minutes, without any warming of the target; 3 no conventional nitrogen cooled shield but rather taking advantage of the cold helium vapours evaporated in the transfer line and/or the helium evaporated to cool the polarized crystal; 4 a heat exchanger which reduces by a factor of two the consumption of helium lowering in the same ratio the transfer line and/or the helium evaporated to cool the polarized crystal; 5 regulation of the temperature by means of a needle valve included in the superfluid helium line. This cryostat, used in conjunction with a 1000 l/s pump allows one to maintain at 1.06 deg. K a target, in which is dissipated 1 watt hyper frequency power, with an helium consumption of 40 litres/day (measured directly in the storage dewar). (author) [French] Description d'un cryostat horizontal, a alimentation continue, pour cible de protons polarises, presentant les caracteristiques suivantes: 1 utilisation de vases de stockage de modele commercial; 2 echange de vase en 10 minutes sans rechauffement; 3 absence d'azote liquide remplace par les vapeurs froides de l'helium evapore dans la canalisation de transfert et/ou les vapeurs de l'helium evapore pour refroidir le cristal polarise; 4 utilisation d'un echangeur qui aboutit a reduire de moitie la consommation d'helium, donc la pression d'evaporation, et qui permet, pour une pompe donnee, d'abaisser la temperature de fonctionnement de 0.1 degre environ; 5 reglage de la temperature au moyen d'une vanne a aiguille placee sur le circuit d'helium prerefroidi (superfluide). Ce cryostat, utilise avec une pompe de 1000 l/s permet de maintenir a une temperature de 1.06 deg. K une cible dans laquelle est dissipee une puissance d'hyperfrequence de 1 watt, moyennant une consommation d'helium de 40 litres/jour (mesuree dans le vase de stockage). (auteur)

Partial molar volumes of hydrogen and deuterium in niobium and vanadium

International Nuclear Information System (INIS)

Herro, H.M.

1979-01-01

Lattice dilation studies and direct pressure experiments gave comparable values for the partial molar volumes of hydrogen and deuterium in niobium and vanadium. Small isotope effects in the partial molar volume of hydrogen were measured in both metals by the differential isotope method. Hydrogen had a larger partial molar volume than deuterium in niobium, but the reverse was true in vanadium. The isotope effect measured in niobium can be represented as being due to the larger amplitude of vibration of the hydrogen atom than the deuterium atom in the metal lattice. Since hydrogen has a larger mean displacement from the equilibrium position than does deuterium, the average force hydrogen exerts on the metal atoms is greater than the force deuterium exerts. The isotope effect in vanadium is likely a result of anharmonic effects in the lattice and local vibrational modes