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Sample records for antineutrino charge-exchange reactions

  1. Neutrino and antineutrino charge-exchange reactions on 12C

    International Nuclear Information System (INIS)

    Samana, A. R.; Krmpotic, F.; Paar, N.; Bertulani, C. A.

    2011-01-01

    We extend the formalism of weak interaction processes, obtaining new expressions for the transition rates, which greatly facilitate numerical calculations, for both neutrino-nucleus reactions and muon capture. Explicit violation of the conserved vector current hypothesis by the Coulomb field, as well as development of a sum-rule approach for inclusive cross sections, has been worked out. We have done a thorough study of exclusive (ground-state) properties of 12 B and 12 N within the projected quasiparticle random phase approximation (PQRPA). Good agreement with experimental data achieved in this way put into evidence the limitations of the standard RPA and QRPA models, which come from the inability of the RPA to open the p 3/2 shell and from the nonconservation of the number of particles in the QRPA. The inclusive neutrino/antineutrino (ν/ν-tilde) reactions 12 C(ν,e - ) 12 N and 12 C(ν-tilde,e + ) 12 B are calculated within both the PQRPA and the relativistic QRPA. It is found that (i) the magnitudes of the resulting cross sections are close to the sum-rule limit at low energy, but significantly smaller than this limit at high energies, for both ν and ν-tilde; (ii) they increase steadily when the size of the configuration space is augmented, particularly for ν/ν-tilde energies >200 MeV; and (iii) they converge for sufficiently large configuration space and final-state spin. The quasi-elastic 12 C(ν,μ - ) 12 N cross section recently measured in the MiniBooNE experiment is briefly discussed. We study the decomposition of the inclusive cross section based on the degree of forbiddenness of different multipoles. A few words are dedicated to the ν/ν-tilde- 12 C charge-exchange reactions related to astrophysical applications.

  2. Forward pion-nucleon charge exchange reaction and Regge constraints

    International Nuclear Information System (INIS)

    Huang Fei; Sibirtsev, A.; Krewald, S.; Hanhart, C.; Haidenbauer, J.; Meibner, U.-G.

    2009-01-01

    We present our recent study of pion-nucleon charge exchange amplitudes above 2 GeV. We analyze the forward pion-nucleon charge exchange reaction data in a Regge model and compare the resulting amplitudes with those from the Karlsruhe-Helsinki and George-Washington-University partial-wave analyses. We explore possible high-energy constraints for theoretical baryon resonance analyses in the energy region above 2 GeV. Our results show that for the pion-nucleon charge exchange reaction, the appropriate energy region for matching meson-nucleon dynamics to diffractive scattering should be around 3 GeV for the helicity flip amplitude. (authors)

  3. Charge exchange reactions and the efficiency of solar neutrino detectors

    International Nuclear Information System (INIS)

    Austin, S.M.; Anantaraman, N.; Love, W.G.

    1994-01-01

    The efficiencies of solar neutrino detectors are often based in part on weak interaction strengths determined by (p,n) and other charge exchange reactions. Although the (p,n) determinations are surprisingly good, it is shown that they may be inaccurate for important Gamow-Teller transitions whose strengths are a small fraction of the sum rule limit. This emphasizes the importance of direct calibration with ν sources for detectors such as 127 I and 115 In where direct β-decay information cannot be obtained. It may also bear on recent attempts to compare charge exchange and beta decay in the mass-37 system

  4. Studies of nuclear structure in antinucleon charge-exchange reactions

    International Nuclear Information System (INIS)

    Auerbach, N.

    1986-01-01

    The antinucleon-nucleus charge exchange reaction is discussed an its use as a probe of isovector excitations in nuclei is described. Attention is drawn to the fact that the (anti p,anti n) reaction will predominantly excite ''pionic'' (i.e., longitudinal spin) modes in nuclei. Comparison between (anti p,anti n) and (n,p) reactions is made. Plans for (anti p,anti n) experiments in the near future are mentioned. 21 refs., 3 figs

  5. Elastic scattering and charge exchange reactions with exotic beams

    International Nuclear Information System (INIS)

    Roussel-Chomaz, P.; Cortina-Gil, M.D.; Mittig, W.; Alamanos, N.; Auger, F.; Fekou-Youmbi, V.; Barrette, J.; Blumenfeld, Y.; Frascaria, N.; Al-Khalili, J.

    1996-01-01

    The elastic scattering of 6 He, 10,11 Be secondary beams on a (CH 2 ) 3 target and the charge exchange reaction p( 6 He, 6 Li)n have been measured. Very good agreement was found for the 6 He+ 12 C data with a four-body eikonal scattering model. A microscopic optical potential was used to reproduce the proton-nucleus elastic scattering data. (author)

  6. Charge-exchange reactions with a secondary triton beam

    CERN Document Server

    Sherrill, B M; Austin, S M; Bazin, D; Berg, A; Berg, G P A; Caggiano, J; Daito, I; Fujimura, H; Fujita, Y; Fujiwara, M; Hara, K; Harakeh, M N; Jänecke, J; Kawabata, T; Navin, A; Roberts, D A; Steiner, M

    1999-01-01

    A secondary triton beam from fragmentation of 560-MeV alpha-particles has been used in a high-resolution (t, sup 3 He) charge-exchange experiment at intermediate bombarding energies. The experiment was carried out at the National Superconducting Cyclotron Laboratory using a sup 4 He beam from the K1200 cyclotron. The radioactive triton beam of (0.5-1.0)x10 sup 6 particles/s with a mean energy of 350 MeV was produced in a production target of the A1200 fragment separator and transported to the target position of the S800 magnetic spectrometer. Ray-tracing and dispersion-matching techniques were employed to detect sup 3 He particles from the sup 1 sup 2 C(t, sup 3 He) sup 1 sup 2 B reaction near 0 deg. . An energy resolution of DELTA E approx 160 keV or DELTA E/E approx 4.6x10 sup - sup 4 (FWHM) was achieved. This is an improvement over our previous results and opens the possibility for studying high-resolution (n,p)-type reactions at intermediate bombarding energies. (author)

  7. Tensor exchange amplitudes in K +- N charge exchange reactions

    International Nuclear Information System (INIS)

    Svec, M.

    1979-01-01

    Tensor (A 2 ) exchange amplitudes in K +- N charge exchange (CEX) are constructed from the K +- N CEX data supplemented by information on the vector (rho) exchange amplitudes from πN sca tering. We observed new features in the t-structure of A 2 exchange amplitudes which contradict the t-de pendence anticipated by most of the Regge models. The results also provide evidence for violation of weak exchange degeneracy

  8. Cross sections and rate coefficients for charge exchange reactions of protons with hydrocarbon molecules

    International Nuclear Information System (INIS)

    Janev, R.K.; Kato, T.; Wang, J.G.

    2001-05-01

    The available experimental and theoretical cross section data on charge exchange processes in collisions of protons with hydrocarbon molecules have been collected and critically assessed. Using well established scaling relationships for the charge exchange cross sections at low and high collision energies, as well as the known rate coefficients for these reactions in the thermal energy region, a complete cross section database is constructed for proton-C x H y charge exchange reactions from thermal energies up to several hundreds keV for all C x H y molecules with x=1, 2, 3 and 1 ≤ y ≤ 2x + 2. Rate coefficients for these charge exchange reactions have also been calculated in the temperature range from 0.1 eV to 20 keV. (author)

  9. Charge Exchange Reaction in Dopant-Assisted Atmospheric Pressure Chemical Ionization and Atmospheric Pressure Photoionization.

    Science.gov (United States)

    Vaikkinen, Anu; Kauppila, Tiina J; Kostiainen, Risto

    2016-08-01

    The efficiencies of charge exchange reaction in dopant-assisted atmospheric pressure chemical ionization (DA-APCI) and dopant-assisted atmospheric pressure photoionization (DA-APPI) mass spectrometry (MS) were compared by flow injection analysis. Fourteen individual compounds and a commercial mixture of 16 polycyclic aromatic hydrocarbons were chosen as model analytes to cover a wide range of polarities, gas-phase ionization energies, and proton affinities. Chlorobenzene was used as the dopant, and methanol/water (80/20) as the solvent. In both techniques, analytes formed the same ions (radical cations, protonated molecules, and/or fragments). However, in DA-APCI, the relative efficiency of charge exchange versus proton transfer was lower than in DA-APPI. This is suggested to be because in DA-APCI both dopant and solvent clusters can be ionized, and the formed reagent ions can react with the analytes via competing charge exchange and proton transfer reactions. In DA-APPI, on the other hand, the main reagents are dopant-derived radical cations, which favor ionization of analytes via charge exchange. The efficiency of charge exchange in both DA-APPI and DA-APCI was shown to depend heavily on the solvent flow rate, with best efficiency seen at lowest flow rates studied (0.05 and 0.1 mL/min). Both DA-APCI and DA-APPI showed the radical cation of chlorobenzene at 0.05-0.1 mL/min flow rate, but at increasing flow rate, the abundance of chlorobenzene M(+.) decreased and reagent ion populations deriving from different gas-phase chemistry were recorded. The formation of these reagent ions explains the decreasing ionization efficiency and the differences in charge exchange between the techniques. Graphical Abstract ᅟ.

  10. Study of the charge-exchange reaction 24 Mg(t,3 He)

    International Nuclear Information System (INIS)

    Gareev, F.A.; Semchenkov, A.G.

    1994-01-01

    The charge-exchange reaction 24 Mg(t, 3 He) in the region of Δ-isobar excitation at initial momentum 9.15 GeV/c is analyzed using (π + ρ + g')-model and effective number formalism. Contribution from different topologies and their influence on Δ-isobar inclusive peak are considered. (author). 15 refs., 9 figs., 3 tabs

  11. Electron capture rates in stars studied with heavy ion charge exchange reactions

    Science.gov (United States)

    Bertulani, C. A.

    2018-01-01

    Indirect methods using nucleus-nucleus reactions at high energies (here, high energies mean ~ 50 MeV/nucleon and higher) are now routinely used to extract information of interest for nuclear astrophysics. This is of extreme relevance as many of the nuclei involved in stellar evolution are short-lived. Therefore, indirect methods became the focus of recent studies carried out in major nuclear physics facilities. Among such methods, heavy ion charge exchange is thought to be a useful tool to infer Gamow-Teller matrix elements needed to describe electron capture rates in stars and also double beta-decay experiments. In this short review, I provide a theoretical guidance based on a simple reaction model for charge exchange reactions.

  12. SU3 comparison of line reversed charge exchange and hypercharge exchange reactions

    International Nuclear Information System (INIS)

    Damerell, C.J.S.; Ratcliff, B.N.; Wickens, F.; Buran, T.; Homer, R.J.; Wilson, J.A.

    1975-01-01

    The recent data at 10.1 GeV/c on the hypercharge exchange reactions π + p→K + Σ + and π + p→K + Σ + (1385) and the line reversed processes are compared with the SU 3 related charge exchange processes K + n→K 0 p and K + p→K 0 Δ ++ and their line reversed partners in order to study the systematics of line reversal breaking. Allowing for a t-independent SU 3 breaking between charge and hypercharge exchange the data follow the SU 3 relations. It is concluded that the line reversal breaking in the hypercharge exchange reactions is in agreement with the breaking in exchange degeneracy (in both flip and non-flip amplitudes) which is observed for the charge exchange processes. (Auth.)

  13. Elastic scattering and charge exchange reaction studies with 6He, 10,11Be

    International Nuclear Information System (INIS)

    Roussel-Chomaz, P.; Cortina-Gil, M.D.; Mittig, W.; Casandjian, J.M.; Chartier, M.; Alamanos, N.; Auger, F.; Fekou-Youmbi, V.; Blumenfeld, Y.

    1995-01-01

    The elastic scattering and charge exchange reaction of 6 He, 10,11 Be secondary beams on proton and 12 C targets have been measured. The combined use of SISSI and SPEG allowed to obtain very good quality data in terms of energy and angular resolution. Preliminary analyses of the angular distributions using global parameter set for the optical model potentials, as well as more microscopic approaches are presented. (author)

  14. Moving Towards a State of the Art Charge-Exchange Reaction Code

    Science.gov (United States)

    Poxon-Pearson, Terri; Nunes, Filomena; Potel, Gregory

    2017-09-01

    Charge-exchange reactions have a wide range of applications, including late stellar evolution, constraining the matrix elements for neutrinoless double β-decay, and exploring symmetry energy and other aspects of exotic nuclear matter. Still, much of the reaction theory needed to describe these transitions is underdeveloped and relies on assumptions and simplifications that are often extended outside of their region of validity. In this work, we have begun to move towards a state of the art charge-exchange reaction code. As a first step, we focus on Fermi transitions using a Lane potential in a few body, Distorted Wave Born Approximation (DWBA) framework. We have focused on maintaining a modular structure for the code so we can later incorporate complications such as nonlocality, breakup, and microscopic inputs. Results using this new charge-exchange code will be shown compared to the analysis in for the case of 48Ca(p,n)48Sc. This work was supported in part by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through the U.S. DOE Cooperative Agreement No. DE- FG52-08NA2855.

  15. Effects of energy dependent Δ-nucleus optical potential in charge exchange reactions

    International Nuclear Information System (INIS)

    Helgesson, J.; Dmitriev, V.

    1994-01-01

    The Δ-nucleus optical potential from microscopic calculations in nuclear matter is used to study the effects of its energy dependence in charge-exchange (p, n) and ( 3 He, T) reactions. The neutron or triton spectrum is calculated via response function of a finite nucleus accounting for pion renormalization effects and short-range correlations. Only very small effects, 1-2%, were found for ( 3 He, T) reaction where the changes in the high energy part of the triton spectrum are enhanced relative to the low-energy part by ( 3 He, T) form factor. For the (p, n) reaction no visible effects were found. (orig.)

  16. The 10B (7Li, 7Be)10Be charge-exchange reaction

    International Nuclear Information System (INIS)

    Etchegoyen, A.

    1987-01-01

    It is analysed the mechanisms: direct charge-exchange through the two-body residual force (Q opt ∼ 0.2 MeV, which is close to the reaction Q-value of - 1,42 MeV); and single-Nucleon Knock-on exchange (SNKE) due to the intereacting nucleons being undistinguishable. These mechanisms are analysed in detail for producing 10 B ( 7 Li, 7 Be) 10 Be reaction. The experience was carried out at the Tandar Laboratory using conventional electronics. The elastic scattering was simultaneously measured in order to obtain an optical model parameter set. (M.C.K.) [pt

  17. Reaction mechanism and nuclear correlations study by low energy pion double charge exchange

    International Nuclear Information System (INIS)

    Weinfeld, Z.

    1993-06-01

    In pion double-charge-exchange (DCX) reactions, a positive (negative) pion is incident on a nucleus and a negative (positive) pion emerges. These reactions are of fundamental interest since the process must involve at least two nucleons in order to conserve charge. Although two nucleon processes are present in many reactions they are usually masked by the dominant single nucleon processes. DCX is unique in that respect since it is a two nucleon process in lowest order and thus may be sensitive to two-nucleon correlations. Measurements of low energy pion double-charge-exchange reactions to the double-isobaric-analog-state (DIAS) and ground-state (GS) of the residual nucleus provide new means for studying nucleon-nucleon correlations in nuclei. At low energies (T π 7/2 shell at energies ranging from 25 to 65 MeV. Cross sections were measured on 42,44,48 Ca, 46,50 Ti and 54 Fe. The calcium isotopes make a good set of nuclei on which to study the effects of correlations in DCX reactions

  18. Neutrino nuclear responses for double beta decays and astro neutrinos by charge exchange reactions

    Science.gov (United States)

    Ejiri, Hiroyasu

    2014-09-01

    Neutrino nuclear responses are crucial for neutrino studies in nuclei. Charge exchange reactions (CER) are shown to be used to study charged current neutrino nuclear responses associated with double beta decays(DBD)and astro neutrino interactions. CERs to be used are high energy-resolution (He3 ,t) reactions at RCNP, photonuclear reactions via IAR at NewSUBARU and muon capture reactions at MUSIC RCNP and MLF J-PARC. The Gamow Teller (GT) strengths studied by CERs reproduce the observed 2 neutrino DBD matrix elements. The GT and spin dipole (SD) matrix elements are found to be reduced much due to the nucleon spin isospin correlations and the non-nucleonic (delta isobar) nuclear medium effects. Impacts of the reductions on the DBD matrix elements and astro neutrino interactions are discussed.

  19. Quasielastic scattering charge exchange p3He→nFppp reaction at mean energies

    International Nuclear Information System (INIS)

    Blinov, A.V.; Vanyushin, I.A.; Grechko, V.E.

    1988-01-01

    The main characteristics of the quasi-elastic charge-exchange reaction p 3 He → n F ppp (where n F is fast neutron in the rest frame of 3 He nucleus) are studied making use of the ITEP 80-cm liquid-hydrogen bubble chamber exposed in the 3 He beams of 2.5 and 5 GeV/c momenta (the kinetic energy T p of the primary protons in the rest frame of the nucleus is, respectively, 0.318 and 0.978 GeV). The experimental data are compared with the Galuber - Sitenko multiple scattering theory predictions and with the pole-model calculations taking into account the final-state interaction of the spectator nucleons. In the mass spectrum of the 3p system at 3.05 GeV a prominent structure has been observed which cannot be described by the pole model. Possible resonance nature of this structure is discussed

  20. The neutron-proton charge-exchange amplitudes measured in the dp {yields} ppn reaction

    Energy Technology Data Exchange (ETDEWEB)

    Mchedlishvili, D.; Chiladze, D. [Tbilisi State University, High Energy Physics Institute, Tbilisi (Georgia); Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Juelich (Germany); Barsov, S.; Dzyuba, A. [Petersburg Nuclear Physics Institute, High Energy Physics Department, Gatchina (Russian Federation); Carbonell, J. [Universite Paris-Sud, IN2P3-CNRS, Institut de Physique Nucleaire, Orsay Cedex (France); Dymov, S. [JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); Universitaet Erlangen-Nuernberg, Physikalisches Institut II, Erlangen (Germany); Engels, R.; Gebel, R.; Hartmann, M.; Kacharava, A.; Kamerdzhiev, V.; Lehrach, A.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Rathmann, F.; Serdyuk, V.; Seyfarth, H.; Stein, H.J.; Stockhorst, H.; Stroeher, H. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Juelich (Germany); Glagolev, V. [JINR, Laboratory of High Energies, Dubna (Russian Federation); Grigoryev, K.; Mikirtychyants, M.; Mikirtychyants, S.; Valdau, Yu. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Juelich (Germany); Petersburg Nuclear Physics Institute, High Energy Physics Department, Gatchina (Russian Federation); Goslawski, P.; Khoukaz, A.; Mielke, M.; Papenbrock, M. [Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Keshelashvili, I. [Tbilisi State University, High Energy Physics Institute, Tbilisi (Georgia); University of Basel, Department of Physics, Basel (Switzerland); Komarov, V.; Kulikov, A. [JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); Kulessa, P. [H. Niewodniczanski Institute of Nuclear Physics PAN, Krakow (Poland); Lomidze, N.; Nioradze, M.; Tabidze, M. [Tbilisi State University, High Energy Physics Institute, Tbilisi (Georgia); Macharashvili, G. [Tbilisi State University, High Energy Physics Institute, Tbilisi (Georgia); JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); Merzliakov, S. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Juelich (Germany); JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); Steffens, E. [Universitaet Erlangen-Nuernberg, Physikalisches Institut II, Erlangen (Germany); Trusov, S. [Forschungszentrum Rossendorf, Institut fuer Kern- und Hadronenphysik, Dresden (Germany); Uzikov, Yu. [JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); M. V. Lomonosov Moscow State University, Department of Physics, Moscow (Russian Federation); Wilkin, C. [UCL, Physics and Astronomy Department, London (United Kingdom)

    2013-04-15

    The unpolarised differential cross section and the two deuteron tensor analysing powers A{sub xx} and A{sub yy} of the vector dp {yields} {l_brace}pp{r_brace}{sub s}n charge-exchange reaction have been measured with the ANKE spectrometer at the COSY storage ring. Using deuteron beams with energies 1.2, 1.6, 1.8, and 2.27GeV, data were obtained for small momentum transfers to a {l_brace}pp{r_brace}{sub s} system with low excitation energy. The results at the three lower energies are consistent with impulse approximation predictions based upon the current knowledge of the neutron-proton amplitudes. However, at 2.27GeV, where these amplitudes are far more uncertain, agreement requires a reduction in the overall double-spin-flip contribution, with an especially significant effect in the longitudinal direction. These conclusions are supported by measurements of the deuteron-proton spin-correlation parameters C{sub x,x} and C{sub y,y} that were carried out in the vector dvector p {yields} {l_brace}pp{r_brace}{sub s}n reaction at 1.2 and 2.27GeV. The values obtained for the proton analysing power A{sub y}{sup p} also suggest the need for a radical re-evaluation of the neutron-proton elastic scattering amplitudes at the higher energy. It is therefore clear that such measurements can provide a valuable addition to the neutron-proton database in the charge-exchange region. (orig.)

  1. Tritons for the study of the charge-exchange reactions with the LHE streamer chamber: status and some possibilities

    International Nuclear Information System (INIS)

    Avramenko, S.A.; Belikov, Yu.A.; Golokhvastov, A.I.; Kirillov, A.D.; Khorozov, S.A.; Komolov, L.N.; Lukstin'sh, Yu.; Rukoyatkin, P.A.

    1997-01-01

    The 6 and 9 GeV/c secondary tritons, produced in the 4 He+A→ 3 H+X reaction, were used to study the charge-exchange reactions using a streamer chamber in magnetic field. The triton formation schemes, the beam parameters achieved as well as a way to reduce the beam momentum spread are given in the paper

  2. Study of the pd→→n{pp}s charge-exchange reaction using a polarised deuterium target

    Directory of Open Access Journals (Sweden)

    B. Gou

    2015-02-01

    Full Text Available The vector and tensor analysing powers, Ay and Ayy, of the pd→→n{pp}s charge-exchange reaction have been measured at a beam energy of 600 MeV at the COSY-ANKE facility by using an unpolarised proton beam incident on an internal storage cell target filled with polarised deuterium gas. The low energy recoiling protons were measured in a pair of silicon tracking telescopes placed on either side of the target. Putting a cut of 3 MeV on the diproton excitation energy ensured that the two protons were dominantly in the S01 state, here denoted by {pp}s. The polarisation of the deuterium gas was established through measurements in parallel of proton–deuteron elastic scattering. By analysing events where both protons entered the same telescope, the charge-exchange reaction was measured for momentum transfers q≥160 MeV/c. These data provide a good continuation of the earlier results at q≤140 MeV/c obtained with a polarised deuteron beam. They are also consistent with impulse approximation predictions with little sign evident for any modifications due to multiple scatterings. These successful results confirm that the ANKE deuteron charge-exchange programme can be extended to much higher energies with a polarised deuterium target than can be achieved with a polarised deuteron beam.

  3. Excitation of the Δ resonance in heavy ion charge exchange reactions

    International Nuclear Information System (INIS)

    Roy-Stephan, M.

    1987-06-01

    Results on the Δ excitation by heavy ion charge exchange are presented. 900 MeV per nucleon 12 C, 16 0, 20 Ne and 1100 MeV per nucleon 12 C have been used. The Δ excitation strength depends on the projectile - ejectile nature and on the incident energy. The role of the target mass is also discussed. The peak for the Δ in nuclei is energy shifted from the free Δ peak

  4. A study of the charge-exchange reaction $pp \\to n\\Delta^{++} (1232)$ at ISR energies

    CERN Document Server

    De Kerret, H; Bartl, Walter; Brandt, A; Broll, C; Coignet, G; Dibon, Heinz; Eichinger, H; Favier, Jean; Flügge, G; Gottfried, Christian; Massonnet, Louis; Nagy, E; Neuhofer, G; Niebergall, F; Orr, R S; Regler, Meinhard; Schmidt-Parzefall, W; Schubert, K R; Schumacher, P E; Vivargent, M; Winter, Klaus

    1977-01-01

    A study is reported of the charge-exchange reaction pp to n Delta /sup ++/(1232) at the CERN intersecting storage rings (ISR) in the energy range square root s=23 to 53 GeV. From the analysis of the energy dependence of the total cross-section, of the differential cross- section d sigma /dt and of the decay angular distributions evidence is found that pion exchange is dominant up to square root s=23 GeV and that ( rho +A/sub 2/) exchange dominates the reaction for square root s>or=30 GeV, as described by simple Regge-pole models. (13 refs).

  5. Study of charged current reactions induced by muon antineutrinos

    International Nuclear Information System (INIS)

    Huss, D.

    1979-07-01

    We present in this work a study of antineutrino reactions on light targets. We have used the Gargamelle cloud chamber with a propane-freon mix. In the 2 first chapters we give a brief description of the experimental setting and we present the selection criteria of the events. In the third chapter we analyse the data for the reaction anti-ν + p → μ + + n that preserves strangeness. We have deduced the values of the axial (M A ) and vector (M V ) form factors: M A = (O.92 ± 0.08) GeV and M V = (0.86 ± 0.04) GeV. In the fourth chapter we study reactions in which strange particles appear (ΔS = 1) and we have determined their production cross-sections. The elastic reaction: anti-ν + p → μ + + Λ is studied in a more accurate manner thanks to a 3-constraint adjustment that enables the selection of events occurring on free protons. We have deduced from our data the longitudinal, orthogonal and transverse polarization of Λ, we have got respectively P l = -0.06 ± 0.44; P p = 0.29 ± 0.41; P t 1.05 ± 0.30. We have also deduced the values of the total cross-section as a function of the incident antineutrino energy E: σ (0.27 ± 0.02)*E*10 -38 cm -2 . E has been assessed from the energy deposited in the cloud chamber and we have adjusted the cross-section with a straight line as it is expected under the assumption of scale invariance. (A.C.)

  6. A phenomenological study of the π- p → π0 n charge exchange reaction at high energy

    International Nuclear Information System (INIS)

    Michaud, Y.

    1995-01-01

    The aim of the study was to examine the behaviour of the proton-proton elastic scattering, for mass center energies around 10 GeV, and more especially to study the charge exchange reaction π - p → π 0 n for mass center energies between 3 and 20 GeV. A formalism based on the Glauber model has been used, and a Regge trajectory exchange term was introduced in the model in order to enable the description of the lower energy domain (inferior to 10 GeV) that is characterized by a large contribution of meson exchanges at the scattering amplitude. The Glauber model is then applied to the charge exchange reaction and the differential cross section is analyzed for a center mass energy comprised between 3 and 20 GeV, together with the polarization at 40 GeV/c. The approach is then validated through the study of the π - p → η n reaction. The size of the kernel of proton and pion components implied in the π - p → π 0 n reaction, is also investigated. 90 refs., 48 figs., 4 tabs., 5 appends

  7. A high-statistics measurement of the pp→nn charge-exchange reaction at 875 MeV/c

    International Nuclear Information System (INIS)

    Lamanna, M.; Ahmidouch, A.; Birsa, R.; Bradamante, F.; Bressan, A.; Bressani, T.; Dalla Torre-Colautti, S.; Giorgi, M.; Heer, E.; Hess, R.; Kunne, R.A.; Lechanoine-Le Luc, C.; Martin, A.; Mascarini, C.; Masoni, A.; Penzo, A.; Rapin, D.; Schiavon, P.; Tessarotto, F.

    1995-01-01

    A new measurement of the differential cross section and of the analysing power A 0n of the charge-exchange reaction pp→nn at 875 MeV/c is presented. The A 0n data cover the entire angular range and constitute a considerable improvement over previously published data, both in the forward and in the backward hemisphere. The cross-section data cover only the backward region, but are unique at this energy. A careful study of the long-term drifts of the apparatus has allowed to fully exploit the good statistics of the data. ((orig.))

  8. NUMEN Project @ LNS : Heavy ions double charge exchange reactions towards the 0νββ nuclear matrix element determination

    Energy Technology Data Exchange (ETDEWEB)

    Agodi, C., E-mail: agodi@lns.infn.it; Calabretta, L.; Calanna, A.; Carbone, D.; Cavallaro, M.; Colonna, M.; Cuttone, G.; Finocchiaro, P.; Pandola, L.; Rifuggiato, D.; Tudisco, S. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Cappuzzello, F.; Greco, V. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); Bonanno, D. L.; Bongiovanni, D. G.; Longhitano, F. [INFN - Sezione di Catania, Catania (Italy); Branchina, V. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); Foti, A.; Lo Presti, D. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); INFN - Sezione di Catania, Catania (Italy); Lanzalone, G. [Università di Enna, Enna (Italy); and others

    2015-10-28

    In the NUMEN Project it is proposed an innovative technique to access the nuclear matrix elements entering in the expression of the life-time of the neutrinoless double beta decay, using relevant cross sections of double charge exchange reactions. A key aspect is the use of MAGNEX large acceptance magnetic spectrometer, for the detection of the ejectiles, and of the INFN Laboratori Nazionali del Sud (LNS) K800 Superconducting Cyclotron (CS), for the acceleration of the required high resolution and low emittance heavy-ion beams.

  9. Charge-exchange and fusion reaction measurements during compression experiments with neutral beam heating in the Tokamak Fusion Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kaita, R.; Heidbrink, W.W.; Hammett, G.W.; Chan, A.A.; England, A.C.; Hendel, H.W.; Medley, S.S.; Nieschmidt, E.; Roquemore, A.L.; Scott, S.D.

    1986-04-01

    Adiabatic toroidal compression experiments were performed in conjunction with high power neutral beam injection in the Tokamak Fusion Test Reactor (TFTR). Acceleration of beam ions to energies nearly twice the injection energy was measured with a charge-exchange neutral particle analyzer. Measurements were also made of 2.5 MeV neutrons and 15 MeV protons produced in fusion reactions between the deuterium beam ions and the thermal deuterium and /sup 3/He ions, respectively. When the plasma was compressed, the d(d,n)/sup 3/He fusion reaction rate increased a factor of five, and the /sup 3/He(d,p)/sup 4/He rate by a factor of twenty. These data were simulated with a bounce-averaged Fokker-Planck program, which assumed conservation of angular momentum and magnetic moment during compression. The results indicate that the beam ion acceleration was consistent with adiabatic scaling.

  10. Charge-exchange and fusion reaction measurements during compression experiments with neutral beam heating in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Kaita, R.; Heidbrink, W.W.; Hammett, G.W.

    1986-04-01

    Adiabatic toroidal compression experiments were performed in conjunction with high power neutral beam injection in the Tokamak Fusion Test Reactor (TFTR). Acceleration of beam ions to energies nearly twice the injection energy was measured with a charge-exchange neutral particle analyzer. Measurements were also made of 2.5 MeV neutrons and 15 MeV protons produced in fusion reactions between the deuterium beam ions and the thermal deuterium and 3 He ions, respectively. When the plasma was compressed, the d(d,n) 3 He fusion reaction rate increased a factor of five, and the 3 He(d,p) 4 He rate by a factor of twenty. These data were simulated with a bounce-averaged Fokker-Planck program, which assumed conservation of angular momentum and magnetic moment during compression. The results indicate that the beam ion acceleration was consistent with adiabatic scaling

  11. Quasi-elastic transfer and charge-exchange reactions in collisions of 48Ti on 42Ca and 26Mg

    International Nuclear Information System (INIS)

    Brendel, C.

    1985-01-01

    At the GSI magnetic spectrometer quasi-elastic transfer and charge-exchange reactions of the system 48 Ti + 42 Ca at incident energies E lab = 240, 300, and 385 MeV and additionally at the higher projectile energy the system 48 Ti + 26 Mg were studied each in the excitation energy range up to E x ≅ 80 MeV. The transition strength was for each particle-hole configuration of the final system calculated by means of the DWBA and subsequently folded with a Breit-Wigner distribution. The localization of the strength of the cross section and the specific structure of the energy spectra were at incident energies between 6 and 8 MeV/amu for all angles well reproduced. By an extension of the core-excitation model to many-stage reactions the charge-exchange reaction 48 Ti + 42 Ca → 48 Sc + 42 Sc could be described as sequential two-stage process. In the two-neutron stripping reaction 48 Ti + 42 Ca → 46 Ti + 44 Ca a surprisingly narrow line with a width of the experimental resolution and an excitation energy of E x = 17.8 MeV was measured at angles smaller than the grazing angle. In the 48 Ti + 26 Mg system the corresponding 46 Ti spectra show also under forward angles structures at excitation energies between 8 and 16 MeV. These lines can be explained as two-neutron states with high spin. (orig./HSI) [de

  12. Study of electric isovector giant nuclear resonances by the charge exchange reaction. Search for a monopole mode

    International Nuclear Information System (INIS)

    Berat, C.

    1988-01-01

    Charge exchange reactions ( 13 C, 13 N) and ( 13 C, 13 B) at 50 MeV/n are studied with the purpose of investigating the electric isovector modes of giant nuclear resonances in 12 C, 40 Ca, 58 Ni, 60 Ni, 90 Zr, 120 Sn and 208 Pb, and especially the monopole mode. Measurements have been performed at GANIL, using the magnetic spectrometer SPEG. The main characteristics of giant nuclear resonances are reviewed, and the ability of the chosen reactions to excite electric isovector modes is examined. Experimental setup and data reduction are described. Results are commented and analyzed. The analog state of the dipole resonance is strongly excited in nuclei with A ≤ 60; excitation energies and widths are obtained with a good accuracy. For nuclei with A ≥ 60, a large peak is observed in the spectra. Its excitation energy is closed to the excitation energy of the giant isovector monopole resonance, measured with the (π - , π 0 ) reaction, except in 208 Pb. Experimental angular distributions do not quite show the features expected from DWBA calculations. The low-lying states of 12 N and 12 B are used to test the calculations and the reaction mechanisms [fr

  13. Intermediate energy charge-exchange reactions induced by polarized 3He

    International Nuclear Information System (INIS)

    Kim, B.T.

    1998-01-01

    Spin polarization transfer is proven to be very useful in obtaining detailed information of the continuum nuclear responses. The data, taken for the (vector p,vector n) reactions, have enabled us to separate the response into the spin longitudinal and transverse components. These partial nuclear responses have been successfully used to make critical tests of nuclear structure models. In the present paper, we first summarize the results of the data and the theoretical analyses made so far. We then discuss information obtainable from the ( 3 vector He,vector t) reaction, emphasizing on the differences and similarities in comparison with the (vector p,vector n) reaction. The results of numerical calculations made for ( 3 vector He,vector t) reactions based on the microscopic distorted wave impulse approximation will also be reported. (orig.)

  14. The influence of the charge-exchange reactions of carbon in the photoionization models for spectrum-line emitting region in the quasi-stellar objects

    International Nuclear Information System (INIS)

    Souza Pellegrini, P.S. de.

    1976-08-01

    The charge exchange reactions: C +2 + H sub(e) 0 → H +1 + C +1 and C +2 + H 0 → H +1 + C +1 were taken into account in the ionization equilibrium of Carbon in photoionization models for line emitting regions of quasi-stellar objects. The new ionization structure of Carbon was obtained and the intensities of the most important emission lines of this element usually observed in QSO's with large redshifts were calculated. The charge exchange with Hidrogen produces negligible effects while the importance of taking into account the charge exchange with Helium can be seen from the change of the ionization structure of Carbon in all considered models. The homogeneous optically thin model is shown not to be consistent with the observations. For non homogeneous optically thick models observable changes in line intensities occur when in the region where charge exhange is dominant the electron density is high enough to produce collisional excitation and consequent line emission. (Author)

  15. Effects of small components of 3He wave function in quasi-elastic charge exchange reaction P+3He→nF+(ppp) at intermediate energies

    International Nuclear Information System (INIS)

    Blinov, A.V.; Solov'ev, V.V.

    1991-01-01

    The contribution to the cross sections of the quasi-elastic charge-exchange reaction p+ 3 He→n p +(ppp) from the S and D components of the 3 He wave function is calculated at zero momentum transfer in the farmework of the impulse approximation taking into account the spin of the particles

  16. Interference effects in inclusive charge-exchange p+p→n+X and n+p→p+X reactions at intermediate energies

    International Nuclear Information System (INIS)

    Gareev, F.A.; Ratis, Yu.L.; Korovin, P.P.; Strokovskij, E.A.; Vaagen, J.S.

    1992-01-01

    The formalism of Feynman diagrams to describe charge-exchange reactions p+p→n+X and n+p→p+X on a free proton target taking into account spectator and decay modes in the π+ρ+g'-model have used. It is shown that the interference between these modes depends on the set of vertex function parameters used. It is also shown that the constructive interference of the Δ + and Δ 0 -isobars is important. 22 refs.; 10 figs

  17. $\\beta$- decay of $^{58}$Zn. A critical test for the charge-exchange reaction as a probe for the $\\beta$- decay strength distribution

    CERN Multimedia

    2002-01-01

    % IS353 \\\\ \\\\ Due to its importance in fundamental physics and astrophysics, a great effort both theoretically and experimentally is devoted to study Gamow Teller (GT)-strength. The GT-strength and its distribution play a key role in late stellar evolution. During the pre-supernova core-collapse of massive stars, the electron capture and nuclear $\\beta$ -decay determine the electron-to-baryon ratio, which influences the infall dynamics and the mass of the final core. The cross-section of the charge-exchange reaction at forward angles with energies above 100~MeV is expected to be proportional to the squares of Fermi and GT matrix elements. This proportionality should provide a Q-value free method to probe the weak interaction strength and renormalization effects in nuclei. Thus charge-exchange reactions are often used to determine the experimental GT-strength. However, the connection between the GT-strength and the cross-section of the charge-exchange reaction is partially model-dependent and the question aris...

  18. Calculation of reactor antineutrino spectra in TEXONO

    CERN Document Server

    Chen Dong Liang; Mao Ze Pu; Wong, T H

    2002-01-01

    In the low energy reactor antineutrino physics experiments, either for the researches of antineutrino oscillation and antineutrino reactions, or for the measurement of abnormal magnetic moment of antineutrino, the flux and the spectra of reactor antineutrino must be described accurately. The method of calculation of reactor antineutrino spectra was discussed in detail. Furthermore, based on the actual circumstances of NP2 reactors and the arrangement of detectors, the flux and the spectra of reactor antineutrino in TEXONO were worked out

  19. ABC's of pion charge exchange

    International Nuclear Information System (INIS)

    Gibbs, W.R.; Kaufmann, W.B.; Siegel, P.B.

    1985-01-01

    Calculations of pion single charge exchange using the PWIA and DWIA are presented. Emphasis is given to the effects of absorbtion and blocking. A microscopic calculation of the 0 0 excitation and low energy angular distribution is in excellent agreement with the data. A fixed nucleon multiple scattering calculation of the pion double charge exchange reaction is presented. Various valence neutron wave functions are used, and the contributions of different spatial orientations of the last two neutrons to the reaction are examined. The DCX cross section is found to be very sensitive to the inclusion of correlations in the two-neutron wave function. Satisfactory agreement with DCX data on 14 C can be obtained using a nucleonic picture of the nucleus

  20. Intermediate energy nuclear physics (Task C) and charge exchange reactions (Task W). Technical progress report, October 1, 1985-October 1, 1986

    International Nuclear Information System (INIS)

    Kraushaar, J.J.

    1986-10-01

    This report describes the experimental work in intermediate energy research carried out over the past year at the University of Colorado. The experimental program is very broad in nature, ranging from investigations in pion-nucleus interactions, nucleon charge exchange, inelastic electron scattering, and nucleon transfer reactions. The experiments were largely carried out at the Los Alamos Meson Physics Facility, but important programs were conducted at the Tri-University Meson Facility at the University of British Columbia, the Indiana University Cyclotron Facility and Netherlands Institute for Nuclear Physics Research (NIKHEF-K)

  1. A new potential of π-nucleus scattering and its application to nuclear structure study using elastic scattering and charge exchange reactions

    International Nuclear Information System (INIS)

    Durand, Gerard.

    1974-01-01

    First the different theories used for studying pion-nucleus scattering and especially Glauber microscopic model and Kisslinger optical model are summarized. From the comparison of these two theories it was concluded that Kisslinger's was better for studying pion-nucleus scattering near the (3/2-3/2) resonance. The potential was developed, with a local corrective term, proposed by this author. This new term arises from taking into account correctly the Lorentz transformation from the pion-nucleon center of mass to the pion nucleus center of mass system. A coupled-channel formalism was developed allowing the study of pion-nucleus elastic scattering and also the study of single and double charge exchange reactions on nucleus with N>Z. The influence of the new term and the shape of nucleon densities on π- 12 C scattering was studied near 200MeV. It was found that at the nucleus surface the neutron density was larger than the proton density. On the other hand, a maximum of sensibility to the different nuclear parameters was found near 180MeV and for elastic scattering angles greater than 100 deg. The calculations of the total cross section for simple and double charge exchange for 13 C and 63 Cu yielded results simular to those of previous theories and showed the same discrepancy between theory and experiment in the resonance region [fr

  2. Study of the elastic scattering and of the (p,n) charge exchange reaction with neutron-rich light exotic beams

    International Nuclear Information System (INIS)

    Cortina Gil, D.

    1996-01-01

    We have measured at GANIL, with the high resolution spectrometer SPEG, the elastic scattering of several neutron rich secondary beams ( 6 He, 10 Be and 11 Be) on a polypropylene target and the charge exchange reaction p( 6 He, 6 Li)n. These exotic beams were produced by nuclear fragmentation and re-focalized with the SISSI device (superconducting solenoids). The signature of a halo structure in these nuclei has been analysed. Special attention has been paid to several aspects of the associated calculations namely, the proton and neutron density distributions and the small binding energy for the last nucleons in these exotic nuclei. Break-up mechanisms are seen to play an important role in these nuclei

  3. Nuclear structure and the single charge exchange

    International Nuclear Information System (INIS)

    Oset, E.; Strottman, D.

    1979-01-01

    The influence of nuclear structure on meson-induced single-charge-exchange reactions on light nuclei is discussed within the context of the Glauber approximation. Selection rules which are expected to be approximately obeyed in elastic and inelastic pion and kaon scattering are proposed. Theoretical predictions are presented for (π + ,π 0 ) and (K + ,K 0 ) reactions on 13 C. 14 figures

  4. Charge exchange, surface-induced dissociation and reactions of doubly charged molecular ions SF42+ upon impact on a stainless steel surface: A comparison with surface-induced dissociation of singly charged SF4+ molecular ions

    Czech Academy of Sciences Publication Activity Database

    Feketeová, L.; Grill, V.; Zappa, F.; Endstrasser, N.; Rasul, B.; Herman, Zdeněk; Scheier, P.; Märk, T. D.

    2008-01-01

    Roč. 276, č. 1 (2008), s. 37-42 ISSN 1387-3806 Institutional research plan: CEZ:AV0Z40400503 Keywords : doubly charged ion * surface-induced dissociations * surface-induced reaction * charge exchange Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.445, year: 2008

  5. Charge exchange in ion-atom collisions

    International Nuclear Information System (INIS)

    Bransden, B.H.

    1990-01-01

    Charge exchange reactions in which electrons are transferred from one ion (or atom) to another during a collision have been studied both as interesting examples of rearrangement collisions and because of important applications in plasma physics. This article reviews the modern theory developed for use at non-relativistic energies, but excluding the thermal and very low energy region. (author)

  6. Study of neutral current reactions with production of a pion induced by muon antineutrinos

    International Nuclear Information System (INIS)

    Guyonnet, J.L.

    1981-03-01

    In this work we have studied the 4 production reactions of a pion induced by muon anti-neutrino collisions with nucleons: anti-ν μ p → anti-ν μ pπ 0 or anti-ν μ nπ + and anti-ν μ n → anti-ν μ nπ 0 or anti-ν μ pπ - . We have processed experimental data from the Gargamelle cloud chamber to assess the pion production cross-sections. Our results are consistent with the theoretical predictions of the Adler model and of the Fogli and Nardulli model within the framework of the Weinberg and Salam unified theory. As for the isospin structure of the weak hadronic neutral current, the iso-vectorial component is highlighted in the invariant mass spectra in the channels pπ 0 and pπ - . Our results show that the isospin structure is not purely isoscalar or purely iso-vectorial but rather a mix of I = 0 and I = 1. We confirm that the sign of the product of the 2 coupling constants u L *d L is negative. (A.C.)

  7. Sodium vapor charge exchange cell

    International Nuclear Information System (INIS)

    Hiddleston, H.R.; Fasolo, J.A.; Minette, D.C.; Chrien, R.E.; Frederick, J.A.

    1976-01-01

    An operational sequential charge-exchange ion source yielding a 50 MeV H - current of approximately 8 mA is planned for use with the Argonne 500 MeV booster synchrotron. Progress is reported on the development of a sodium vapor charge-exchange cell as part of that planned effort. Design, fabrication, and operating results to date are presented and discussed

  8. Sodium vapor charge exchange cell

    International Nuclear Information System (INIS)

    Hiddleston, H.R.; Fasolo, J.A.; Minette, D.C.; Chrien, R.E.; Frederick, J.A.

    1976-01-01

    An operational sequential charge-exchange ion source yielding a 50 MeV H - current of approximately 8 mA is planned for use with the Argonne 500 MeV booster synchrotron. We report on the progress for development of a sodium vapor charge-exchange cell as part of that planned effort. Design, fabrication, and operating results to date are presented and discussed. (author)

  9. Double charge exchange of pions on nuclei

    International Nuclear Information System (INIS)

    Dzhibuti, R.I.; Kezerashvili, R.Y.

    1985-01-01

    An analysis is made of the results of experimental and theoretical studies during the last ten years of a unique process: double charge exchange of pions on nuclei. On the one hand, the commissioning of meson factories and the use of new and more accurate experimental methods have led to the accumulation of rich and reliable material for not only light but also medium and heavy nuclei. On the other hand, the development and application of new microscopic theoretical approaches have led to a deepening of our ideas about the mechanism of these exotic reactions at low, intermediate, and high energies. The currently existing methods of theoretical investigation and all possible reaction mechanisms are considered. Particular attention is devoted to double charge exchange of pions on the lightest nuclei, for the theoretical description of which it is possible to use the well-developed methods for investigating few-particle systems. The experimental investigations of double-isobar analog and nonanalog transitions in the reaction of double charge exchange are systematized

  10. Tokamak rotation and charge exchange

    International Nuclear Information System (INIS)

    Hazeltine, R.D.; Rowan, W.L.; Solano, E.R.; Valanju, P.M.

    1991-01-01

    In the absence of momentum input, tokamak toroidal rotation rates are typically small - no larger in particular than poloidal rotation - even when the radial electric field is strong, as near the plasma edge. This circumstance, contradicting conventional neoclassical theory, is commonly attributed to the rotation damping effect of charge exchange, although a detailed comparison between charge-exchange damping theory and experiment is apparently unavailable. Such a comparison is attempted here in the context of recent TEXT experiments, which compare rotation rates, both poloidal and toroidal, in helium and hydrogen discharges. The helium discharges provide useful data because they are nearly free of ion-neutral charge exchange; they have been found to rotate toroidally in reasonable agreement with neoclassical predictions. The hydrogen experiments show much smaller toroidal motion as usual. The theoretical calculation uses the full charge-exchange operator and assumes plateau collisionality, roughly consistent with the experimental conditions. The authors calculate the ion flow as a function of v cx /v c , where v cx is the charge exchange rate and v c the Coulomb collision frequency. The results are in reasonable accord with the observations. 1 ref

  11. Transition density of charge-exchange processes

    International Nuclear Information System (INIS)

    Lovas, R.G.

    1983-01-01

    The transition density between parent and analogue states is studied with special reference to its role in charge-exchange nuclear reactions. The structure of the target nucleus is described in a perturbative approach, in which the Coulomb and asymmetry potentials mix the eigenstates of a charge-independent single-particle Hamiltonian. In this model formulae are derived for the transition density, the Coulomb displacement energy and the neutron-proton density difference, and their relationship is used to estimate the transition density. This estimate shows that: the largest contribution comes from the density of the excess neutrons; the weight of the Coulomb-mixing effect is small up to excess neutron number 10, and grows rapidly beyond; the weight of the core polarization term induced by the excess neutrons is modest and is the same for all nuclei. It is indicated that the Coulomb effect may explain the departure from the Lane model of nucleon charge-exchange scattering found for heavy nuclei, whereas the core polarization may account for the observed anomalous dependence of the deg 0 pion charge-exchange cross section on the number of excess neutrons. (author)

  12. 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

  13. H- charge exchange injection systems

    International Nuclear Information System (INIS)

    Ankenbrandt, C.; Curtis, C.; Hojvat, C.; Johnson, R.P.; Owen, C.; Schmidt, C.; Teng, L.; Webber, R.C.

    1980-01-01

    The techniques and components required for injection of protons into cyclic accelerators by means of H - charge exchange processes are reviewed, with emphasis on the experience at Fermilab. The advantages of the technique are described. The design and performance of the system of injection of H - ions into the Fermilab Booster are detailed. (Auth.)

  14. Charge exchange in galaxy clusters

    Science.gov (United States)

    Gu, Liyi; Mao, Junjie; de Plaa, Jelle; Raassen, A. J. J.; Shah, Chintan; Kaastra, Jelle S.

    2018-03-01

    Context. Though theoretically expected, the charge exchange emission from galaxy clusters has never been confidently detected. Accumulating hints were reported recently, including a rather marginal detection with the Hitomi data of the Perseus cluster. As previously suggested, a detection of charge exchange line emission from galaxy clusters would not only impact the interpretation of the newly discovered 3.5 keV line, but also open up a new research topic on the interaction between hot and cold matter in clusters. Aim. We aim to perform the most systematic search for the O VIII charge exchange line in cluster spectra using the RGS on board XMM-Newton. Methods: We introduce a sample of 21 clusters observed with the RGS. In order to search for O VIII charge exchange, the sample selection criterion is a >35σ detection of the O VIII Lyα line in the archival RGS spectra. The dominating thermal plasma emission is modeled and subtracted with a two-temperature thermal component, and the residuals are stacked for the line search. The systematic uncertainties in the fits are quantified by refitting the spectra with a varying continuum and line broadening. Results: By the residual stacking, we do find a hint of a line-like feature at 14.82 Å, the characteristic wavelength expected for oxygen charge exchange. This feature has a marginal significance of 2.8σ, and the average equivalent width is 2.5 × 10-4 keV. We further demonstrate that the putative feature can be barely affected by the systematic errors from continuum modeling and instrumental effects, or the atomic uncertainties of the neighboring thermal lines. Conclusions: Assuming a realistic temperature and abundance pattern, the physical model implied by the possible oxygen line agrees well with the theoretical model proposed previously to explain the reported 3.5 keV line. If the charge exchange source indeed exists, we expect that the oxygen abundance could have been overestimated by 8-22% in previous X

  15. Observation of a meson X → 2γ, with mass 2.85 GeV/c2, produced in the charge-exchange reaction π-p→Xn at 40 Gev/c

    International Nuclear Information System (INIS)

    Apel, W.D.; Augenstein, K.H.; Bertolucci, E.; Donskov, S.V.; Inyakin, A.V.; Kachanov, V.A.; Krasnokutsky, R.N.; Kruger, M.; Leder, G.; Lednev, A.A.; Mannelli, I.; Mikhailov, Yu.V.; Mueller, H.; Pierazzini, G.M.; Prokoshkin, Yu.D.; Quaglia, M.; Schneider, H.; Scribano, A.; Sergiampietri, F.; Shuvalov, R.S.; Sigurdsson, G.; Toropin, A.N.; Vincelli, M.L.

    1978-01-01

    The invariant mass spectrum of neutral final states produced in π - p charge-exchange scattering at 40 GeV/c has been studied, searching for heavy particles decaying into 2γ. A peak is observed around 2.85 GeV/c 2 . The cross section of the reaction π - p→X(2.85)+n, times the branching ratio of the X→2γ decay, is measured to be sigma X BR approximately =2X10 -34 cm 2 . (Auth.)

  16. Single- and double-charge exchange at low pion energies

    International Nuclear Information System (INIS)

    Baer, H.W.

    1991-01-01

    A review is given of pion single- and double-charge exchange reactions at incident energies of 25 to 65 MeV leading to isobaric analog states, and in the case of double-charge exchange leading to the ground state of the residual nucleus. The crucial role of the higher nuclear transparency at low pion energies for the analysis of the data in terms of single and double scattering is demonstrated. The large effects on double-charge exchange produced by the spatial correlations in nuclear wave functions are evident. The data on 1f 7/2 nuclei at 35 MeV are used to establish the general validity of a shell-model-based two-amplitude model for these transitions. Recent measurements of the energy dependence between 25 and 65 MeV of double-charge exchange cross sections at forward angles are presented and discussed. 33 refs., 19 figs

  17. Systematics of pion double charge exchange

    International Nuclear Information System (INIS)

    Gilman, R.A.

    1985-10-01

    Differential cross sections have been measured for pion-induced double-charge-exchange (DCX) reactions leading to double-isobaric-analog states (DIAS) and low-lying nonanalog states in the residual nuclei. A description of the experimental details and data analysis is presented. The experimentally observed systematics of reactions leading to DIAS, to nonanalog ground states, and to low-lying 2 + states are described. Lowest-order optical-model calculations of DIAS DCX are compared to the data. Efforts to understand the anomalies by invoking additional reaction-mechanism amplitudes and a higher-order optical potential are described. Calculations of nonanalog DCX reactions leading to J/sup π/ = 0 + states were performed within a distorted-wave impulse-approximation framework. The sensitivities of these calculations to input parameters are discussed. 58 refs., 41 figs., 16 tabs

  18. Systematics of pion double charge exchange

    Energy Technology Data Exchange (ETDEWEB)

    Gilman, R.A.

    1985-10-01

    Differential cross sections have been measured for pion-induced double-charge-exchange (DCX) reactions leading to double-isobaric-analog states (DIAS) and low-lying nonanalog states in the residual nuclei. A description of the experimental details and data analysis is presented. The experimentally observed systematics of reactions leading to DIAS, to nonanalog ground states, and to low-lying 2 states are described. Lowest-order optical-model calculations of DIAS DCX are compared to the data. Efforts to understand the anomalies by invoking additional reaction-mechanism amplitudes and a higher-order optical potential are described. Calculations of nonanalog DCX reactions leading to J/sup / = 0 states were performed within a distorted-wave impulse-approximation framework. The sensitivities of these calculations to input parameters are discussed. 58 refs., 41 figs., 16 tabs.

  19. O--H charge exchange in cold, dense, hydrogen plasmas

    International Nuclear Information System (INIS)

    Cohen, S.A.; Dylla, H.F.

    1977-05-01

    It is pointed out that the accidentally resonant charge exchange reaction, O + + H 0 reverse arrows O 0 + H + , is an important mechanism for causing the loss of singly charged oxygen ions from oxygen contaminated hydrogen plasmas. Results of a Monte Carlo simulation are presented which show that the fraction of oxygen lost because of charge exchange exceeds 1 / 3 when the parameters n/sub e/ approx. 10 13 cm -3 , n/sub H//sup o/ approx. 10 11 cm -3 and T/sub e/ approx. 3 eV are attained

  20. The effect of charge exchange with neutral deuterium on carbon emission in JET divertor plasmas

    International Nuclear Information System (INIS)

    Maggi, C.; Horton, L.; Summers, H.

    1999-11-01

    High density, low temperature divertor plasma operation in tokamaks results in large neutral deuterium concentrations in the divertor volume. In these conditions, low energy charge transfer reactions between neutral deuterium and the impurity ions can in principle enhance the impurity radiative losses and thus help to reduce the maximum heat load to the divertor target. A quantitative study of the effect of charge exchange on carbon emission is presented, applied to the JET divertor. Total and state selective effective charge exchange recombination rate coefficients were calculated in the collisional radiative picture. These coefficients were coupled to divertor and impurity transport models to study the effect of charge exchange on the measured carbon spectral emission in JET divertor discharges. The sensitivity of the effect of charge exchange to the assumptions in the impurity transport model was also investigated. A reassessment was made of fundamental charge exchange cross section data in support of this study. (author)

  1. The effect of charge exchange with neutral deuterium on carbon emission in JET divertor plasmas

    International Nuclear Information System (INIS)

    Maggi, C.F.; Horton, L.D.; Summers, H.P.

    2000-01-01

    High-density, low-temperature divertor plasma operation in tokamaks results in large neutral deuterium concentrations in the divertor volume. Under these conditions, low-energy charge transfer reactions between neutral deuterium and the impurity ions can, in principle, enhance the impurity radiative losses and thus help to reduce the maximum heat load to the divertor target. A quantitative study of the effect of charge exchange on carbon emission is presented, and applied to the JET divertor. Total and state-selective effective charge exchange recombination rate coefficients were calculated in the collisional radiative picture. These coefficients were coupled to divertor and impurity transport models in order to study the effect of charge exchange on the measured carbon spectral emission in JET divertor discharges. The sensitivity of the effect of charge exchange to the assumptions in the impurity transport model was also investigated. A reassessment of fundamental charge exchange cross section data in support of this study was made. (author)

  2. Pion double charge exchange above the Δ(1232) resonance

    International Nuclear Information System (INIS)

    Williams, A.L.; Moore, C.F.; Agnew, L.; Atencio, L.G.; Baer, H.W.; McGill, J.A.; Morris, C.L.; Schilling, S.; Burlein, M.; Fortune, H.T.; O'Donnell, J.M.; Silk, J.D.; Burleson, G.R.; Kyle, G.S.; Dhuga, K.S.; Mordechai, S.; Rawool, M.W.; Zumbro, J.D.

    1989-01-01

    First measurements of exclusive cross sections for the (π + ,π - ) reaction at incident energies of 300-500 MeV are reported. For the analog-state transitions in 14 C and 18 O the 5 0 cross sections are found to remain nearly constant in this energy interval. This behavior is in disagreement both with predictions based on six-quark cluster models and with simple expectations based on recent single-charge-exchange measurements. (orig.)

  3. Nonadiabatic ionic--covalent transitions. Exponential-linear model for the charge exchange and neutralization reactions Na+H arrow-right-left Na/sup +/+H/sup -/

    Energy Technology Data Exchange (ETDEWEB)

    Errea, L.F.; Mendez, L.; Mo, O.; Riera, A.

    1986-01-01

    A previous study of charge exchange processes taking place through ionic--covalent transitions is extended to the case of Na+H and Na/sup +/+H/sup -/ collisions. A five-state molecular expansion, with the inclusion of two-electron translation factors, is employed to calculate the charge exchange and neutralization cross sections. Transitions at the first two pseudocrossings between the energy curves, practically determine the cross sections in the energy range 0.16--5 keV amu/sup -1/. We also show that the widely used multichannel Landau--Zener theory is totally inadequate, to treat these transitions.

  4. A phenomenological study of the {pi}{sup -} p {yields} {pi}{sup 0} n charge exchange reaction at high energy; Etude phenomenologique de la reaction d`echange de charge {pi}{sup -} p {yields} {pi}{sup 0} n a haute energie

    Energy Technology Data Exchange (ETDEWEB)

    Michaud, Y.

    1995-09-21

    The aim of the study was to examine the behaviour of the proton-proton elastic scattering, for mass center energies around 10 GeV, and more especially to study the charge exchange reaction {pi}{sup -} p {yields} {pi}{sup 0} n for mass center energies between 3 and 20 GeV. A formalism based on the Glauber model has been used, and a Regge trajectory exchange term was introduced in the model in order to enable the description of the lower energy domain (inferior to 10 GeV) that is characterized by a large contribution of meson exchanges at the scattering amplitude. The Glauber model is then applied to the charge exchange reaction and the differential cross section is analyzed for a center mass energy comprised between 3 and 20 GeV, together with the polarization at 40 GeV/c. The approach is then validated through the study of the {pi}{sup -} p {yields} {eta} n reaction. The size of the kernel of proton and pion components implied in the {pi}{sup -} p {yields} {pi}{sup 0} n reaction, is also investigated. 90 refs., 48 figs., 4 tabs., 5 appends.

  5. Net charge of quark jets in (anti)neutrino interactions

    International Nuclear Information System (INIS)

    Teper, M.

    1981-01-01

    We analyse recent measurements of the net charges of quark jets in neutrino and antineutrino interactions. The data indicates that (i) the two quarks in the nucleon fragmentation region prefer to behave as a diquark rather than as a pair of independent quarks, and (ii) the struck quark does not appear to suffer any soft charge exchange of the kind that occurs when a valence quark inside a nucleon is slowed to x approx. O. (orig.)

  6. μ+ charge exchange and muonium formation in low pressure gases

    International Nuclear Information System (INIS)

    Fleming, D.G.; Mikula, R.J.; Garner, D.M.

    1982-04-01

    Using the basic muon spin rotation technique, the fractions of energetic positive muons thermalizing in diamagnetic environments (fsub(μ)) or as the paramagnetic muonium atom (fsub(Mu)) have been measured in low pressure pure gases (He, Ne, Ar, Kr, Xe, H 2 , N 2 , NH 3 , and CH 4 ) as well as in several gas mixtures (Ne/Xe, Ne/Ar, Ne/NH 3 , Ne/CH 4 ). In the pure gases, the muonium fractions fsub(Mu) are generally found to be smaller than expected from analogous proton charge exchange studies, particularly in the molecular gases. This is probably due to hot atom reactions of muonium following the charge exchange regime. Comparisons with monium formation in condensed matter as well as positronium formation in gases are also presented. In the gas mixtures, the addition of only a few hundred ppm of a dopant gas, which is exothermic for muonium formation (e.g. Xe), gives rise to an fsub(Mu) characteristic of the pure dopant gas itself, demonstrating the importance of the neutralization process right down to thermal energies. In all cases, the experimental signal amplitudes are found to be strongly pressure dependent, which is interpreted in terms of the time spent by the muon as neutral muonium in the charge exchange regime: tsub(n) < 0.2 ns. This time is generally shorter in the case of molecular gases than in rare gases

  7. Pion double charge exchange and nuclear structure

    International Nuclear Information System (INIS)

    Ginocchio, J.N.

    1987-01-01

    Pion double charge exchange to both the double-analog state and the ground state is studied for medium weight nuclei. The relative cross section of these two transitions and the importance of nuclear structure as a function of pion kinetic energy is examined. 16 figs., 5 tabs

  8. Dissociative charge exchange of H2+

    International Nuclear Information System (INIS)

    Bruijn, D. de.

    1983-01-01

    This thesis is devoted to molecular dissociation, in particular the dissociation of the hydrogen molecule H 2 arising from electron capture of its ion H 2 + in a collision. Thereby the important practical question how a chemical bond can be broken is implicitly addressed. This thesis opens (chapter I) with an overview of the available experimental approaches in molecular physics. Further the simple Demkov model for NRCE is described. In chapter II a novel experimental technique for measurements on dissociative processes is introduced which combines a high efficiency with a high energy resolution. A detailed description of the techniques applied in the detector, which has a high spatial and timing resolution with 30 μm and 350 psec FWHM respectively for the detection of one particle, is given in chapter III. A semi-classical theory for NRCE in the medium energy range between a diatomic molecular ion and an atom is developed in chapter IV. The experiments on dissociative charge exchange of H 2 + with Ar, Mg, Na and Cs targets at keV energies are described in Chapter V. The predissociation of the c 3 PIsub(u)-state of H 2 populated after charge exchange of H 2 with several targets at keV energies; is the subject of chapter VI. In chapter VII, orientational oscillations in the cross section for charge exchange of H 2 + with alkali targets are discussed. The last chapter deals with predissociation of highly excited states in H 2 . (Auth.)

  9. Production of antihydrogen via double charge exchange

    International Nuclear Information System (INIS)

    Muellers, Andreas

    2013-01-01

    Spectroscopy of the 1S-2S transition of antihydrogen confined in a neutral atom trap and comparison with the equivalent spectral line in hydrogen will provide an accurate test of CPT symmetry and the first one in a mixed baryon-lepton system. Also, with neutral antihydrogen atoms, the gravitational interaction between matter and antimatter can be tested unperturbed by the much stronger Coulomb forces. Antihydrogen is regularly produced at CERN's Antiproton Decelerator by three-body-recombination (TBR) of one antiproton and two positrons. The method requires injecting antiprotons into a cloud of positrons, which raises the average temperature of the antihydrogen atoms produced way above the typical 0.5 K trap depths of neutral atom traps. Therefore only very few antihydrogen atoms can be confined at a time. Precision measurements, like laser spectroscopy, will greatly benefit from larger numbers of simultaneously trapped antihydrogen atoms. Therefore, the ATRAP collaboration developed a different production method that has the potential to create much larger numbers of cold, trappable antihydrogen atoms. Positrons and antiprotons are stored and cooled in a Penning trap in close proximity. Laser excited cesium atoms collide with the positrons, forming Rydberg positronium, a bound state of an electron and a positron. The positronium atoms are no longer confined by the electric potentials of the Penning trap and some drift into the neighboring cloud of antiprotons where, in a second charge exchange collision, they form antihydrogen. The antiprotons remain at rest during the entire process, so much larger numbers of trappable antihydrogen atoms can be produced. Laser excitation is necessary to increase the efficiency of the process since the cross sections for charge-exchange collisions scale with the fourth power of the principal quantum number n. This method, named double charge-exchange, was demonstrated by ATRAP in 2004. Since then, ATRAP constructed a new combined

  10. Study of the elastic scattering and of the (p,n) charge exchange reaction with neutron-rich light exotic beams; Etude de la diffusion elastique et de la reaction d`echange de charge (p,n) avec des faisceaux exotiques legers riches en neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Cortina Gil, D.

    1996-07-05

    We have measured at GANIL, with the high resolution spectrometer SPEG, the elastic scattering of several neutron rich secondary beams ({sup 6}He, {sup 10}Be and {sup 11}Be) on a polypropylene target and the charge exchange reaction p({sup 6}He, {sup 6}Li)n. These exotic beams were produced by nuclear fragmentation and re-focalized with the SISSI device (superconducting solenoids). The signature of a halo structure in these nuclei has been analysed. Special attention has been paid to several aspects of the associated calculations namely, the proton and neutron density distributions and the small binding energy for the last nucleons in these exotic nuclei. Break-up mechanisms are seen to play an important role in these nuclei. 100 refs.

  11. Charge exchange processes involving iron ions

    International Nuclear Information System (INIS)

    Phaneuf, R.A.

    1985-01-01

    A review and evaluation is given of the experimental data which are available for charge exchange processes involving iron ions and neutral H, H 2 and He. Appropriate scaling laws are presented, and their accuracy estimated for these systems. A bibliography is given of available data sources, as well as of useful data compilations and review articles. A procedure is recommended for providing single approximate formulae to the fusion community to describe total cross sections for electron capture by partially-stripped Fe/sup q+/ ions in collisions with H, H 2 and He, based on the scaling relationships suggested by Janev and Hvelplund

  12. Charge exchange probes of nuclear structure and interactions with emphasis on (p,n)

    International Nuclear Information System (INIS)

    Goodman, C.D.

    1980-01-01

    New results from (p,n) studies at IUCF show that it is possible to observe Gamow-Teller (GT) strength and extract GT matrix elements from (p,n) measurements. The charge exchange reactions ( 6 Li, 6 He) and (π + ,π 0 ) involve different projectile quantum numbers, and the relationships of these reactions to (p,n) is discussed

  13. I. Pion charge-exchange at Fermilab, and II. Some remarks on hadron production at large transverse momenta

    International Nuclear Information System (INIS)

    Pripstein, M.

    1975-06-01

    The discussion of pion charge-exchange and hadron production at large transverse momenta includes the physics motivation, the experimental method event selection criteria, results for the reaction π - p → nπ 0 (eta)

  14. Pion-nucleus double charge exchange and the nuclear shell model

    International Nuclear Information System (INIS)

    Auerbach, N.; Gibbs, W.R.; Ginocchio, J.N.; Kaufmann, W.B.

    1988-01-01

    The pion-nucleus double charge exchange reaction is studied with special emphasis on nuclear structure. The reaction mechanism and nuclear structure aspects of the process are separated using both the plane-wave and distorted-wave impulse approximations. Predictions are made employing both the seniority model and a full shell model (with a single active orbit). Transitions to the double analog state and to the ground state of the residual nucleus are computed. The seniority model yields particularly simple relations among double charge exchange cross sections for nuclei within the same shell. Limitations of the seniority model and of the plane-wave impulse approximation are discussed as well as extensions to the generalized seniority scheme. Applications of the foregoing ideas to single charge exchange are also presented

  15. Charge exchange recombination spectroscopy as a plasma diagnostic tool

    International Nuclear Information System (INIS)

    Fonck, R.J.

    1984-12-01

    Intensity and line profile measurements of the spectra of light hydrogenic ion which are excited by charge exchange reactions with fast neutral atoms are being widely used as diagnostics for fusion plasma research. This technique, which is referred to as charge exchange recombination spectroscopy, allows measurements of the densities of fully stripped impurity ions and particle transport coefficients with only minor uncertainties arising from atomic processes. The excitation of long wavelength transitions in light ions such as He + , C 5+ , and O 7+ allows relatively easy measurements of ion velocity distributions to determine ion temperatures and plasma rotation velocities. Among its advantages for such measurements are the facts that fiber optic coupling between a remote spectrometer and the immediate reactor environment is possible in many cases. The measurement is localized by the intersection region of a neutral beamline and viewing sightline, and intrinsic ions can be used so that injection of potentially perturbing impurities can be avoided. A particularly challenging application of this technique lies in the diagnosis of alpha particles expected to be produced in the present generation of Q approx. = 1 tokamak experiments

  16. Charge exchange recombination x-ray laser

    International Nuclear Information System (INIS)

    Kawachi, Tetsuya; Namba, Shinichi; Kado, Masataka; Tanaka, Momoko; Hasegawa, Noboru; Nagashima, Keisuke; Kato, Yoshiaki

    2001-01-01

    A recombining plasma x-ray laser using charge exchange recombination (CXR) is proposed. Fully stripped carbon ions collide with neutral He atoms and become excited hydrogenlike carbon ions, in which the excited levels with n=3 or 4 are mainly populated. We calculate the gain coefficients of the Balmer α and the Lyman β line of the hydrogenlike carbon ions by the use of a collisional-radiative model in which the CXR process is included. The calculated result shows that substantial gain can be generated for the Lyman β and Balmer α lines and that the gain of the Balmer α line can be strongly enhanced by the effect of CXR. We also report a preliminary experiment of this scheme. (author)

  17. Laboratory simulation of charge exchange-produced X-ray emission from comets.

    Science.gov (United States)

    Beiersdorfer, P; Boyce, K R; Brown, G V; Chen, H; Kahn, S M; Kelley, R L; May, M; Olson, R E; Porter, F S; Stahle, C K; Tillotson, W A

    2003-06-06

    In laboratory experiments using the engineering spare microcalorimeter detector from the ASTRO-E satellite mission, we recorded the x-ray emission of highly charged ions of carbon, nitrogen, and oxygen, which simulates charge exchange reactions between heavy ions in the solar wind and neutral gases in cometary comae. The spectra are complex and do not readily match predictions. We developed a charge exchange emission model that successfully reproduces the soft x-ray spectrum of comet Linear C/1999 S4, observed with the Chandra X-ray Observatory.

  18. Pion double charge exchange on 16O at Tπ=300--500 MeV

    International Nuclear Information System (INIS)

    Beatty, D.P.; Burleson, G.R.; Rawool-Sullivan, M.; El-Ghossain, M.; Fortune, H.T.; Williams, A.L.; Smith, D.A.; Morris, C.L.; Garnett, R.; Watson, D.L.; Johnson, J.; Ward, H.; Whitley, C.; Matthews, S.K.; Palarczyk, M.; Edwards, C.; Espy, M.; Hashimoto, O.; Tomoyuki, H.

    1993-01-01

    Measurements of small-angle cross sections for the pion double-charge-exchange (DCX) reaction 16 O(π + ,π - ) 16 Ne (g.s.) at incident energies of 300--500 MeV are reported. These are the first measurements of DCX cross sections on a T=0 nucleus in this energy region. The behavior of the cross sections is similar to that of analog transitions, but they are smaller by more than an order of magnitude. This suggests sequential charge-exchange scattering as the dominant process, but suppressed by a mechanism not yet identified

  19. Pion double charge exchange in the Δ33 resonance region

    International Nuclear Information System (INIS)

    Wirzba, A.; Toki, H.; Siciliano, E.R.; Johnson, M.B.; Gilman, R.

    1989-01-01

    We examine the model dependence and nuclear-structure sensitivity of several Δ 33 -dominated processes contributing to pion double charge exchange on nuclei in the region of the Δ 33 resonance. These processes include the Δ 33 -nucleon interaction V NΔ and sequential scattering, in which the pion undergoes single charge exchange on two different nucleons. In all cases, the scattering takes place through the exchange of an intermediate π and ρ meson. Sequential-mediated double charge exchange is found to be only moderately sensitive to short-range correlations, meson-nucleon form factors, and the rho meson, whereas V NΔ -mediated double charge exchange is very sensitive to all these effects. Results are given for double charge exchange on 18 O (double isobaric analog transitions) and 16 O (nonanalog transitions). Sequential double charge exchange is shown to favor non-spin-flip matrix elements of the transition operator whereas V NΔ -mediated double charge exchange favors spin-flip matrix elements. The energy dependence of the zero-degree cross sections for V NΔ and sequential scattering are also different: Sequential tends to increase monotonically from 100 to 300 MeV, whereas V NΔ peaks at about 150 MeV. The delta-nucleon interaction is found likely to dominate over sequential scattering in nonanalog double charge exchange. The V NΔ is also large in analog double charge exchange, but it does not enable us to explain the anomalous behavior of the 18 O differential cross sections

  20. Charge-exchange collisions of multiply charged ions with atoms

    International Nuclear Information System (INIS)

    Grozdanov, T.P.; Janev, R.K.

    1978-01-01

    The problem of electron transfer between neutral atoms and multiply charged ions is considered at low and medium energies. It is assumed that a large number of final states are available for the electron transition so that the electron-capture process is treated as a tunnel effect caused by the strong attractive Coulomb field of the multicharged ions. The electron transition probability is obtained in a closed form using the modified-comparison-equation method to solve the Schroedinger equation. An approximately linear dependence of the one-electron transfer cross section on the charge of multicharged ion is found. Cross-section calculations of a number of charge-exchange reactions are performed

  1. X-ray and Far-Ultraviolet emission from comets : Relevant charge exchange processes

    NARCIS (Netherlands)

    Bodewits, D; McCullough, RW; Tielens, AGGM; Hoekstra, R

    2004-01-01

    The surprising detection of strong X-ray and Far-Ultraviolet (FUV) emission from comets is the direct result of charge exchange reactions of multiply-charged solar wind ions with the neutral coma of the comet. A future diagnostics use of spectral features in cometary X-ray and FUV emission is

  2. The reactor antineutrino anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Haser, Julia; Buck, Christian; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2016-07-01

    Major discoveries were made in the past few years in the field of neutrino flavour oscillation. Nuclear reactors produce a clean and intense flux of electron antineutrinos and are thus an essential neutrino source for the determination of oscillation parameters. Most currently the reactor antineutrino experiments Double Chooz, Daya Bay and RENO have accomplished to measure θ{sub 13}, the smallest of the three-flavour mixing angles. In the course of these experiments two anomalies emerged: (1) the reanalysis of the reactor predictions revealed a deficit in experimentally observed antineutrino flux, known as the ''reactor antineutrino anomaly''. (2) The high precision of the latest generation of neutrino experiments resolved a spectral shape distortion relative to the expected energy spectra. Both puzzles are yet to be solved and triggered new experimental as well as theoretical studies, with the search for light sterile neutrinos as most popular explanation for the flux anomaly. This talk outlines the two reactor antineutrino anomalies. Discussing possible explanations for their occurrence, recent and upcoming efforts to solve the reactor puzzles are highlighted.

  3. Nuclear isovector giant resonances excited by pion single charge exchange

    International Nuclear Information System (INIS)

    King, B.H.

    1993-07-01

    This thesis is an experimental study of isovector giant resonances in light nuclei excited by pion single charge exchange reactions. Giant dipole resonances in light nuclei are known to be highly structured. For the mass 9 and 13 giant dipole resonances, isospin considerations were found to be very important to understanding this structure. by comparing the excitation functions from cross section measurements of the (π + , π 0 ) and (π, π 0 ) inclusive reactions, the authors determined the dominant isospin structure of the analog IVGR's. The comparison was made after decomposing the cross section into resonant and non-resonant components. This decomposition is made in the framework of strong absorption and quasi-free scattering. Measurements in the region of the isovector giant dipole resonances (IVGDR) were made to cover the inclusive angular distributions out to the second minimum. Study of the giant resonance decay process provides further understanding of the resonances. This study was carried out by observing the (π + , π 0 p) coincident reactions involving the resonances of 9 B and 13 N excited from 9 Be and 13 C nuclei. These measurements determined the spectra of the decay protons. This method also permitted a decomposition of the giant resonances into their isospin components. The multipolarities of the resonances were revealed by the decay proton angular correlations which, for dipoles, are of the form 1 + A 2 P 2 (cos θ)

  4. Study of isovector resonances with pion charge exchange

    International Nuclear Information System (INIS)

    Baer, H.W.; Bolton, R.; Bowman, J.D.

    1982-01-01

    Studies with the pion charge exchange reactions (π/sup +-/,π 0 ) at 164 MeV using the LAMPF π 0 spectrometer are yielding new results on the existence and systematic features of isovector resonances in nuclei. These experiments possess an unusually high signal/background ratio for isovector resonances of low-multipolarity. Results obtained to date are: (1) observation and angular disribution measurement of the giant dipole resonance in nuclei 12 C, 40 Ca, 90 Zr, and 120 Sn; and (2) observation and angular distribution measurements in the (π - ,π 0 ) reaction on 90 Zr and 120 Sn of large signals possessing the expected angular distribution shapes and magnitudes for the isovector monopole resonance. Excitation energies are near the hydrodynamical model values 170 A - /sup 1/3/ MeV. Differential cross sections are approximately 0.7 J 1 2 (qR) mb/sr. An overview of this experimental program, with emphasis on new results and how they correlate with existing knowledge on the isovector resonances, is presented

  5. Proceedings of the LAMPF workshop on pion double charge exchange

    International Nuclear Information System (INIS)

    Baer, H.W.; Leitch, M.J.

    1985-09-01

    Experimental and theoretical aspects of double-analog, nonanalog, and continuum pion double charge exchange in the 50- to 310-MeV energy range are covered. Separate abstracts were prepared for 22 papers in these proceedings

  6. Measurement of pion double charge exchange on carbon-13, carbon-14, magnesium-26, and iron-56

    International Nuclear Information System (INIS)

    Seidl, P.A.

    1985-02-01

    Cross sections for the /sup 13,14/C, 26 Mg, 56 Fe(π + ,π - )/sup 13,14/O, 26 Si, 56 Ni reactions were measured with the Energetic Pion Channel and Spectrometer at the Clinton P. Anderson Meson Physics Facility for 120 less than or equal to T/sub π/ less than or equal to 292 MeV and 0 less than or equal to theta less than or equal to 50. The double isobaric analog states (DIAS) are of primary interest. In addition, cross sections for transitions to 14 O(0 + , 5.92 MeV), 14 O(2 + , 7.77 MeV), 56 Ni(gs), 13 O(gs), and 13 O(4.21 MeV) are presented. The 13 O(4.21 MeV) state is postulated to have J/sup π/ = 1/2 - . The data are compared to previously measured double-charge-exchange cross sections on other nuclei, and the systematics of double charge exchange on T greater than or equal to 1 target nuclei leading to the DIAS are studied. Near the Δ 33 resonance, cross sections for the DIAS transitions are in disagreement with calculations in which the reaction is treated as sequential charge exchange through the free pion-nucleon amplitude, while for T/sub π/ > 200 MeV the anomalous features of the 164 MeV data are not apparent. This is evidence for significant higher order contributions to the double-charge-exchange amplitude near the reasonable energy. Two theoretical approaches that include two nucleon processes are applied to the DIAS data. 64 references

  7. Resonance charge exchange mechanism at high and moderate energies

    International Nuclear Information System (INIS)

    Bogdanov, A.V.; Gevorkyan, A.S.

    1984-01-01

    Charge exchange mechanisms at high and medium energies are investigated, ta king the resonance charge exchange of a proton by an hydrogen atom as an example . It is established that there are two classical charge exchange mechanisms rel ated to direct proton knockout from the bound state and one quantum-mechanical mechanism corresponding to the electron tunnelling from one bound state to anoth er. The classical cross-section diverges for two of these mechanisms, and the quasiclassical scattering amplitude must be calculated on the base of a complex classical trajectory. Physical grounds for the choice of such trajectories are discussed and calculations of the Van Vleck determinant for these mechanisms a re presented. Contributions from different mechanisms to the total charge excha nge cross-section are analyzed. A comparison with experimental data and results of other authors is made

  8. Charge exchange between singly ionized helium ions

    International Nuclear Information System (INIS)

    Choi, B.H.; Poe, R.T.; Tang, K.T.

    1978-01-01

    The plane-wave Born approximation was used to evaluate the charge transfer cross sections for the reaction He + + He + → He ++ + He. The charge transfer cross section is graphed as a function of incident energy and compared with experimental measurements

  9. The asymptotic theory of resonance charge exchange between diatomics

    International Nuclear Information System (INIS)

    Yevsyev, A.V.; Radtsig, A.A.; Smirnov, B.M.

    1982-01-01

    The asymptotic theory of resonance charge exchange between a ground-state diatomic molecular ion and its neutral parent is presented. The parameters of the valence electron wavefunction and asymptotically precise exchange interaction potential are calculated. The role of rotational transitions is discussed. The vibrational excitation transfer is taken into account and the coupled equations, describing the charge exchange process between diatomics are solved both in limiting cases and numerically. The total charge transfer cross sections are calculated for many diatomic systems and the results are compared with experimental data. (author)

  10. Radiative corrections to Expt. 416. Backward πN charge exchange. Internal report No. 131

    International Nuclear Information System (INIS)

    Chen, G.T.Y.

    The importance of radiative corrections in elastic hadronic reactions has been reported recently. This report describes the computational techniques and results of applying the radiative corrections to a backward charge-exchange scattering experiment. The particular reaction considered is π - p → π 0 + n + γ Evaluation of the Schwinger term, evaluation of the numerical integration term, evaluation of the region in which the photon is detected and a check of the unitarity condition are considered. Appendixes contain listings of computer codes written to calculate radiative corrections. (19 figures, 2 tables) (U.S.)

  11. Charge exchange spectroscopy as a fast ion diagnostic on TEXTOR

    DEFF Research Database (Denmark)

    Delabie, E.; Jaspers, R.J.E.; von Hellermann, M.G.

    2008-01-01

    An upgraded charge exchange spectroscopy diagnostic has been taken into operation at the TEXTOR tokamak. The angles of the viewing lines with the toroidal magnetic field are close to the pitch angles at birth of fast ions injected by one of the neutral beam injectors. Using another neutral beam...

  12. Radiocarbon detection by ion charge exchange mass spectrometry

    International Nuclear Information System (INIS)

    Hotchkis, Michael; Wei, Tao

    2007-01-01

    A method for detection of radiocarbon at low levels is described and the results of tests are presented. We refer to this method as ion charge exchange mass spectrometry (ICE-MS). The ICE-MS instrument is a two stage mass spectrometer. In the first stage, molecular interferences which would otherwise affect radiocarbon detection at mass 14 are eliminated by producing high charge state ions directly in the ion source (charge state ≥2). 14 N interference is eliminated in the second stage by converting the beam to negative ions in a charge exchange cell. The beam is mass-analysed at each stage. We have built a test apparatus consisting of an electron cyclotron resonance ion source and a pair of analysing magnets with a charge exchange cell in between, followed by an electrostatic analyser to improve the signal to background ratio. With this apparatus we have measured charge exchange probabilities for (C n+ → C - ) from 4.5 to 40.5 keV (n = 1-3). We have studied the sources of background including assessment of limits for nitrogen interference by searching for negative ions from charge exchange of 14 N ions. Our system has been used to detect 14 C in enriched samples of CO 2 gas with 14 C/ 12 C isotopic ratio down to the 10 -9 level. Combined with a measured sample consumption rate of 4 ng/s, this corresponds to a capability to detect transient signals containing only a few μBq of 14 C activity, such as may be obtained from chromatographic separation. The method will require further development to match the sensitivity of AMS with a gas ion source; however, even in its present state its sensitivity is well suited to tracer studies in biomedical research and drug development

  13. Cometary X-rays. Solar wind charge exchange in cometary atmospheres

    Science.gov (United States)

    Bodewits, Dennis

    2007-06-01

    The interaction of the solar wind with the planets and the interstellar medium is of key importance for the evolution of our solar system. The interaction with Earth's atmosphere is best known for the northern light. In case of Mars, the interaction with the solar wind might have lead to the erosion of its atmosphere. Solar wind-atmosphere interactions can be studied particularly well in cometary atmospheres, because in that case the solar wind flow is not attenuated by a planetary magnetic field and interacts directly with its atmosphere, the coma. The size of the cometary atmosphere (in the order of 10(4-10^5) km) allows remote tracking of the ions as they penetrate into the comet's atmosphere, offering a unique window on the cometary atmosphere, the solar wind and the interaction of these two plasmas. When solar wind ions fly through an atmosphere they are neutralized via charge exchange reactions with the neutral gaseous species. These reactions depend strongly on target species and collision velocity. The resulting X-ray and Far-UV emission can therefore be regarded as a fingerprint of the underlying reaction, with many diagnostic qualities. My thesis studies have focussed on all aspects relevant for X-ray emission from comets: experimental studies of state-to-state charge exchange cross sections, observations of X-ray emission from comets with Chandra, XMM, and Swift, and theoretical modelling of the interaction of solar wind ions with cometary gasses and the resulting X-ray emission spectrum. Together, this has greatly improved our understanding of the interaction of the solar wind with solar system objects and in more general, of physical processes in wind-environment collisions. The thorough understanding of cometary charge exchange emission has opened the door to the direct observation of more complex solar wind interactions such as those with Mars and Venus.

  14. Molecular (Feshbach) treatment of charge exchange Li/sup 3 +/+He collisions. II. Cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Errea, L.F.; Martin, F.; Mendez, L.; Riera, A.; Yanez, M.

    1986-05-15

    Using the wave functions calculated in the preceding article, and a common translation factor, the charge exchange cross section for the Li/sup 3 +/+He(1s/sup 2/) reaction is calculated, and the mechanism of the process discussed. We show how small deviations from the Landau--Zener model, which are unrelated to Nikitin's conditions for its validity, lead to a minimum of the cross section at an impact energy Eapprox. =1 keV, and to larger values of sigma at intermediate nuclear velocities.

  15. Charge exchange effect on laser isotope separation of atomic uranium

    International Nuclear Information System (INIS)

    Niki, Hideaki; Izawa, Yasukazu; Otani, Hiroyasu; Yamanaka, Chiyoe

    1982-01-01

    Uranium isotope separating experiment was performed using the two-step photoionization technique with dye laser and nitrogen laser by heating uranium metal with electron beam and producing atomic beam using generated vapour. The experimental results are described after explaining the two-step photoionization by laser, experimental apparatus, the selection of exciting wavelength and others. Enrichment factor depends largely on the spectrum purity of dye laser which is the exciting source. A large enrichment factor of 48.3 times was obtained for spectrum width 0.03A. To put the uranium isotope separation with laser into practice, the increase of uranium atomic density is considered to be necessary for improving the yield. Experimental investigation was first carried out on the charge exchange effect that seems most likely to affect the decrease of enrichment factor, and the charge exchange cross-section was determined. The charge exchange cross-section depends on the relative kinetic energy between ions and atoms. The experimental result showed that the cross-section was about 5 x 10 -13 cm 2 at 1 eV and 10 -13 cm 2 at 90 eV. These values are roughly ten times as great as those calculated in Lawrence Livermore Laboratory, and it is expected that they become the greatest factor for giving the upper limit of uranium atomic density in a process of practical application. (Wakatsuki, Y.)

  16. Systematic study of K+ and K- charge exchange at 8.36 and 12.8 GeV/c

    International Nuclear Information System (INIS)

    Gilchriese, M.G.D.

    1977-01-01

    The results of a wire chamber spectrometer experiment at the Stanford Linear Accelerator Center to study kaon charge exchange reactions are reported. The salient experimental features include good relative normalization between the K + and K - charge exchange reactions and a large increase, with respect to previous experiments, in the number of events obtained for K + n charge exchange at the higher energy. Approximately 1500 events at 12.8 GeV/c and 250 events at 8.36 GeV/c were obtained for each of the reactions K + n → K 0 p, K - p → anti K 0 n, K + p → K 0 Δ ++ and K - n → anti K 0 Δ - . The results of the experiment show that the K + charge exchange cross sections are larger than the K - cross sections at both energies. In particular it is found that sigma/sub tot/(K + n → K 0 p)/sigma/sub tot/(K - p → anti K 0 n) is 1.37 +- .22 at 8.36 GeV/c and 1.38 +- 0.9 at 12.8 GeV/c. The ratio of these two reactions is also consistent with no momentum transfer dependence at either beam energy. Similarly it was determined that sigma/sub tot/(K + p → K 0 Δ ++ )/sigma/sub tot/(K - n → anti K 0 Δ - ) is 1.05 +- .16 at 8.36 GeV/c and 1.56 +- .08 at 12.8 GeV/c. The ratio of these two reactions is also consistent with momentum transfer independence for both beam energies. These results are in clear conflict with the predictions of exchange degenerate Regge pole models

  17. Towards Compact Antineutrino Detectors for Safeguarding Nuclear Reactors

    International Nuclear Information System (INIS)

    Meijer, R.J. de; Smit, F.D.; Woertche, H.J.

    2010-01-01

    research programs aim at developing scintillator materials, with a high flame point and weak or no quenching. Moreover we require (Pulse Shape Discrimination) PSD to differentiate between gammas and alphas and Bayesian filtering for background suppression. The second method is triggered by a recent paper indicating an effect of neutrinos on beta- decay. We are investigating the 'mirror' reaction of antineutrinos on beta+ decay. Although we have reduced the effect already by two orders of magnitude, the present upper limit would still allow antineutrino-flux monitoring at nuclear power reactors. (author)

  18. Determination of plasma ion velocity distribution via charge-exchange recombination spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fonck, R.J.; Darrow, D.S.; Jaehnig, K.P.

    1983-12-01

    Spectroscopy of line radiation from plasma impurity ions excited by charge-exchange recombination reactions with energetic neutral beam atoms is rapidly becoming recognized as a powerful technique for measuring ion temperature, bulk plasma motion, impurity transport, and more exotic phenomena such as fast alpha particle distributions. In particular, this diagnostic offers the capability of obtaining space- and time-resolved ion temperature and toroidal plasma rotation profiles with relatively simple optical systems. Cascade-corrected excitation rate coefficients for use in both fully stripped impurity density studies and ion temperature measurements have been calculated to the principal ..delta..n = 1 transitions of He+, C/sup 5 +/, and O/sup 7 +/ with neutral beam energies of 5 to 100 keV/amu. A fiber optically coupled spectrometer system has been used on PDX to measure visible He/sup +/ radiation excited by charge exchange. Central ion temperatures up to 2.4 keV and toroidal rotation speeds up to 1.5 x 10/sup 7/ cm/s were observed in diverted discharges with P/sub INJ/ less than or equal to 3.0 MW.

  19. Elastic and charge-exchange scattering of pions from 3He and 3H

    International Nuclear Information System (INIS)

    Gibson, B.F.; Hess, A.T.

    1976-04-01

    We have examined (1) the elastic scattering of pions from the isodoublet 3 He and 3 H and (2) the single charge-exchange reaction 3 H(π + ,π 0 ) 3 He using a formalism which incorporates the π-N multiple scattering to all orders. Emphasis is placed on numerical results which illustrate those features of the differential cross sections that are expected to be of interest to the experimentalist. Realistic nuclear densities corresponding to the form factors of elastic electron scattering were used. Charge-exchange cross sections are presented in terms of angular distributions for both the π 0 and the recoil nucleus. In elastic scattering, Coulomb-nuclear interference effects are significant at incident pion kinetic energies of less than 100 MeV; form factor effects are apparent at large momentum transfer. Comparison of data and theory for π + - 3 He with that for π - - 3 He (or the conjugate π + - 3 H) will provide a test of the convergence of the fixed scatterer, multiple-scattering formalism utilized in this report. 21 figures

  20. Charge exchange during pion-nucleon scattering at low energy: experiment and analysis

    International Nuclear Information System (INIS)

    Vernin, Pascal

    1972-01-01

    This research thesis lies within the frame of a more general study of pion-nucleon scattering according to the following processes: π + p → π + p; π - p → π - p; π - p → π 0 n. It more precisely addresses the last reaction, so-called charge exchange. Pion-nucleon interactions are described by phase shifts of scattering waves. But the measurement of one of these phase shifts (that of the S wave) requires very low energy pions, and could not have been performed until now with a good precision. In order to fill this gap, the author performed charge exchange experiments at 180 deg. and for energies of 22.6, 33.9 and 42.6 MeV. After a recall on involved theoretical data, the author describes the experimental setup, and reports the detailed study of problems raised by neutron detection. He shows that the analysis of experimental data allows (a 3 - a 1 ) to be obtained with a precision which, without being as high as desired, is nevertheless satisfying [fr

  1. Analysis of JET charge exchange spectra using neural networks

    International Nuclear Information System (INIS)

    Svensson, J.; Hellermann, M. von; Koenig, R.

    1998-01-01

    Active charge exchange spectra representing the local interaction of injected neutral beams and fully stripped impurity ions are hard to analyse due to the strong blending with passive emission from the plasma edge. As a result, the deduced plasma parameters (e.g. ion temperature, rotation velocity, impurity density) can not always be determined unambiguously. Also, the speed of the analysis is limited by the time consuming non-linear least-squares minimisation procedure. In practice, semi-manual analysis is necessary, and fast, automatic analysis, based on currently used techniques, does not seem feasible. In this paper the development of a robust and accurate analysis procedure based on Multi Layer Perception (MLP) neural networks is described. This procedure is fully automatic and fast, thus enabling a real-time analysis of charge exchange spectra. Accuracy has been increased in several ways as compared to earlier straight-forward neural network implementations and is comparable to a standard least squares based analysis. Robustness is achieved by using a combination of different confidence measures. A novel technique for the creation of training data, suitable for high dimensional inverse problems has been developed, and used extensively. A new method for fast calculation of error bars directly from the hidden neurons in a MLP network is also described, and used as part of the confidence calculations. For demonstration purposes, a real-time ion temperature profile diagnostic based on this has been implemented. (author)

  2. Interdefect charge exchange in silicon particle detectors at cryogenic temperatures

    CERN Document Server

    MacEvoy, B; Hall, G; Moscatelli, F; Passeri, D; Santocchia, A

    2002-01-01

    Silicon particle detectors in the next generation of experiments at the CERN Large Hadron Collider will be exposed to a very challenging radiation environment. The principal obstacle to long-term operation arises from changes in detector doping concentration (N/sub eff/), which lead to an increase in the bias required to deplete the detector and hence achieve efficient charge collection. We have previously presented a model of interdefect charge exchange between closely spaced centers in the dense terminal clusters formed by hadron irradiation. This manifestly non-Shockley-Read-Hall (SRH) mechanism leads to a marked increase in carrier generation rate and negative space charge over the SRH prediction. There is currently much interest in the subject of cryogenic detector operation as a means of improving radiation hardness. Our motivation, however, is primarily to investigate our model further by testing its predictions over a range of temperatures. We present measurements of spectra from /sup 241/Am alpha par...

  3. Line Ratios for Solar Wind Charge Exchange with Comets

    Energy Technology Data Exchange (ETDEWEB)

    Mullen, P. D.; Cumbee, R. S.; Lyons, D.; Shelton, R. L.; Stancil, P. C. [Department of Physics and Astronomy and the Center for Simulational Physics, University of Georgia, Athens, GA 30602 (United States); Gu, L.; Kaastra, J., E-mail: pmullen2@illinois.edu [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)

    2017-07-20

    Charge exchange (CX) has emerged in X-ray emission modeling as a significant process that must be considered in many astrophysical environments—particularly comets. Comets host an interaction between solar wind ions and cometary neutrals to promote solar wind charge exchange (SWCX). X-ray observatories provide astronomers and astrophysicists with data for many X-ray emitting comets that are impossible to accurately model without reliable CX data. Here, we utilize a streamlined set of computer programs that incorporate the multi-channel Landau–Zener theory and a cascade model for X-ray emission to generate cross sections and X-ray line ratios for a variety of bare and non-bare ion single electron capture (SEC) collisions. Namely, we consider collisions between the solar wind constituent bare and H-like ions of C, N, O, Ne, Na, Mg, Al, and Si and the cometary neutrals H{sub 2}O, CO, CO{sub 2}, OH, and O. To exemplify the application of this data, we model the X-ray emission of Comet C/2000 WM1 (linear) using the CX package in SPEX and find excellent agreement with observations made with the XMM-Newton RGS detector. Our analyses show that the X-ray intensity is dominated by SWCX with H, while H{sub 2}O plays a secondary role. This is the first time, to our knowledge, that CX cross sections have been implemented into a X-ray spectral fitting package to determine the H to H{sub 2}O ratio in cometary atmospheres. The CX data sets are incorporated into the modeling packages SPEX and Kronos .

  4. KamLAND and Solar Antineutrino Spectrum

    CERN Document Server

    Chauhan, B C; Torrente-Lujan, E; Chauhan, Bhag C.; Pulido, Joao

    2004-01-01

    We use the recent KamLAND observations to predict the solar antineutrino spectrum at some confidence limits. We find that a scaling of the antineutrino probability with respect to the magnetic field profile --in the sense that the same probability function can be reproduced by any profile with a suitable peak field value-- can be utilised to obtain a general shape of the solar antineutrino spectrum. This scaling and the upper bound on the solar antineutrino event rate, that can be derived from the data, lead to: 1) an upper bound on the solar antineutrino flux, 2) the prediction of their energy spectrum, as the normalisation of the spectrum can be obtained from the total number of antineutrino events recorded in the experiment. We get $\\phi_{\\bar\

  5. Daya Bay Antineutrino Detector Gas System

    OpenAIRE

    Band, H. R.; Cherwinka, J. J.; Chu, M-C.; Heeger, K. M.; Kwok, M. W.; Shih, K.; Wise, T.; Xiao, Q.

    2012-01-01

    The Daya Bay Antineutrino Detector gas system is designed to protect the liquid scintillator targets of the antineutrino detectors against degradation and contamination from exposure to ambient laboratory air. The gas system is also used to monitor the leak tightness of the antineutrino detector assembly. The cover gas system constantly flushes the gas volumes above the liquid scintillator with dry nitrogen to minimize oxidation of the scintillator over the five year lifetime of the experimen...

  6. Towards hot electron mediated charge exchange in hyperthermal energy ion-surface interactions

    DEFF Research Database (Denmark)

    Ray, M. P.; Lake, R. E.; Thomsen, Lasse Bjørchmar

    2010-01-01

    electrons useful for driving chemical reactions at surfaces. Using the binary collision approximation and a nonadiabatic model that takes into account the time-varying nature of the ion–surface interaction, the energy loss of the ions is reproduced. The energy loss for Na + ions incident on the devices......We have made Na + and He + ions incident on the surface of solid state tunnel junctions and measured the energy loss due to atomic displacement and electronic excitations. Each tunnel junction consists of an ultrathin film metal–oxide–semiconductor device which can be biased to create a band of hot...... shows that the primary energy loss mechanism is the atomic displacement of Au atoms in the thin film of the metal–oxide–semiconductor device. We propose that neutral particle detection of the scattered flux from a biased device could be a route to hot electron mediated charge exchange....

  7. Inclusive measurements of pion double charge exchange and inelastic scattering on 3He

    International Nuclear Information System (INIS)

    Yuly, M.E.

    1993-06-01

    A measurement was made at the Los Alamos Meson Physics Facility (LAMPF) of the doubly differential cross sections for three inclusive pion reactions on 3 He: π - double charge exchange (DCX), and π + and π - inelastic scattering. The cross sections for DCX were measured at incident energies of 120, 180, 210, and 240 MeV, and at angles of 25, 50, 80, 105, and 130 degrees, while inelastic scattering cross sections were measured at 120, 180, and 240 MeV and scattering angles of 50, 80, 105, and 130 degrees. The final pion energy spectrum was measured from 10 MeV up to the kinematic limit. In the Δ resonance region, where the isospin T = 3/2 channel dominates, the inelastic π - scattering should be almost entirely from the lone neutron in 3 He. The π + inelastic scattering was expected to have significant contributions from both single and double scattering, because the T = 3/2 channel favors π + -p scattering from the two protons in 3 He. The 3 He DCX spectra are similar to those observed for DCX in 4 He. The forward angle double peaks can be understood as a consequence of sequential single charge exchange (SSCX). Calculations using the SSCX model are in rough agreement with the measured shape of the 3 He DCX spectra. The doubly differential cross sections measured for the inelastic scattering reactions exhibit a strong enhancement near the kinematics for free π - -p scattering. The ratios of π + to π - scattering cross sections may indicate multiple scattering, as well as the agreement of the low outgoing energy part of the π + inelastic scattering spectra with the corresponding properly scaled DCX spectra. A distorted-wave impulse-approximation (DWIA) calculation of the quasielastic cross sections has been performed and a comparison made with the measured inelastic cross sections

  8. XMM-Newton Observations of Solar Wind Charge Exchange Emission

    Science.gov (United States)

    Snowden, S. L.; Collier, M. R.; Kuntz, K. D.

    2004-01-01

    We present an XMM-Newton spectrum of diffuse X-ray emission from within the solar system. The spectrum is dominated by O VII and O VIII lines at 0.57 keV and 0.65 keV, O VIII (and possibly Fe XVII) lines at approximately 0.8 keV, Ne IX lines at approximately 0.92 keV, and Mg XI lines at approximately 1.35 keV. This spectrum is consistent with what is expected from charge exchange emission between the highly ionized solar wind and either interstellar neutrals in the heliosphere or material from Earth's exosphere. The emission is clearly seen as a low-energy ( E less than 1.5 keV) spectral enhancement in one of a series of observations of the Hubble Deep Field North. The X-ray enhancement is concurrent with an enhancement in the solar wind measured by the ACE satellite. The solar wind enhancement reaches a flux level an order of magnitude more intense than typical fluxes at 1 AU, and has ion ratios with significantly enhanced higher ionization states. Whereas observations of the solar wind plasma made at a single point reflect only local conditions which may only be representative of solar wind properties with spatial scales ranging from less than half of an Earth radii (approximately 10 s) to 100 Earth radii, X-ray observations of solar wind charge exchange are remote sensing measurements which may provide observations which are significantly more global in character. Besides being of interest in its own right for studies of the solar system, this emission can have significant consequences for observations of more cosmological objects. It can provide emission lines at zero redshift which are of particular interest (e.g., O VII and O VIII) in studies of diffuse thermal emission, and which can therefore act as contamination in objects which cover the entire detector field of view. We propose the use of solar wind monitoring data, such as from the ACE and Wind spacecraft, as a diagnostic to screen for such possibilities.

  9. The PLT and PDX charge-exchange analyzers

    International Nuclear Information System (INIS)

    Mueller, D.; Hammett, G.; McCune, D.C.

    1986-01-01

    The perpendicularly-viewing mass-resolving charge-exchange analyzers for PLT and PDX were built to measure the plasma ion temperature, central neutral density and hydrogen to deuterium ratio. This paper discusses the measurements as they are affected by instrumental effects. In PDX with perpendicular neutral deuterium beam injection into hydrogen plasmas, a small (∼ 1%) hydrogen impurity in the beam gives rise to an energetic tail on the observed hydrogen neutral spectrum. A simple model indicates that this contamination of the thermal spectrum causes the apparent ion temperature to be 5-20% too high. This effect is included in the analysis. The neutral density measurement relies on knowledge of absolute detection efficiency. While this can in principle be measured in-situ with a diagnostic neutral beam, a large uncertainty remains. Measurement of the H/D ratio in the plasma is limited by the mass rejection (1:1000) of the analyzer. It is primarily the deuterium flux at 1/2 the hydrogen energy that places a lower limit on the measurable flux to H/D ratios above ∼ 0.5%

  10. Charge exchange in slow collisions of Si3+ with H

    Science.gov (United States)

    Joseph, D. C.; Saha, B. C.

    2010-10-01

    Low energy electron capture from atomic hydrogen by multi-charged ions continues to be of interest and has wide applications including both magnetically confined^ fusion and astrophysical plasmas. The charge exchange process reported here, Si^3+ + H -- Si^2+ + H^+ is an important destruction mechanism of Si^3+ in photo-ionized gas. The soft X-ray emission from comets has been explained by charge transfer of solar wind ions, among them Si^3+, with neutrals in the cometary gas vapor. The state selective cross sections are evaluated using the semi-classical molecular orbital close coupling (MOCC) [1] methods. Adiabatic potentials and wave functions for a number of low-lying singlet and triplet states are calculated using the MRD-CI package [2]. Details will be presented at the conference. [1] M. Kimura and N. F. Lane, At. Mol. Opt. Phys 26, 79 (1990). [3] R. J. Buenker, ``Current Aspects of Quantum Chemistry'' 1981, Vol 21, edited by R. Carbo (Elsevier, Amsterdam) p 17.

  11. Results obtained using the pellet charge exchange diagnostic on TFTR

    International Nuclear Information System (INIS)

    McChesney, J.M.; Fisher, R.K.; Parks, P.B.; Duong, H.H.; Mansfield, D.K.; Medley, S.S.; Roquemore, A.L.; Petrov, M.P.

    1994-05-01

    Experiments are underway on TFTR to measure the confined alpha particle distribution functions using small low-Z pellets injected into the plasma. Upon entering the plasma, the pellet ablates, forming a plasma ablation cloud, elongated in the magnetic field direction, that travels alongside the pellet. A small fraction of the fusion produced 3.5 MeV alpha particles incident on the cloud are converted to helium neutrals. By measuring the resultant helium neutrals escaping from the plasma by means of a mass and energy resolving charge exchange analyzer, the energy distribution of the alpha particles incident on the cloud can be inferred. Preliminary experiments to observe neutrals from the 100-1000 keV He tail produced during ICRF minority heating experiments were successful. However, no significant alpha particle signals have been observed during D-T operation on TFTR. The authors attribute this lack of signal to stochastic toroidal field ripple loss in the outer regions of the plasma. They are studying ways to improve the pellet penetration so that the pellet penetrates into the central regions of the plasma where ripple induced losses are small and the alpha population is high

  12. Antineutrino Oscillations in the Atmospheric Sector

    Energy Technology Data Exchange (ETDEWEB)

    Himmel, Alexander I. [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2011-05-01

    This thesis presents measurements of the oscillations of muon antineutrinos in the atmospheric sector, where world knowledge of antineutrino oscillations lags well behind the knowledge of neutrinos, as well as a search for vμ → $\\bar{v}$μ transitions. Differences between neutrino and antineutrino oscillations could be a sign of physics beyond the Standard Model, including non-standard matter interactions or the violation of CPT symmetry. These measurements leverage the sign-selecting capabilities of the magnetized steel-scintillator MINOS detectors to analyze antineutrinos from the NuMI beam, both when it is in neutrino-mode and when it is in antineutrino-mode. Antineutrino oscillations are observed at |Δ$\\bar{m}$atm 2| = (3.36-0.40+0.46(stat) ± 0.06(syst)) x 10-3 eV2 and sin2(2$\\bar{θ}$23) = 0.860-0.12+0.11(stat) ± 0.01(syst). The oscillation parameters measured for antineutrinos and those measured by MINOS for neutrinos differ by a large enough margin that the chance of obtaining two values as discrepant as those observed is only 2%, assuming the two measurements arise from the same underlying mechanism, with the same parameter values. No evidence is seen for neutrino-to-antineutrino transitions.

  13. Charge exchange processes of high energy heavy ions channeled in crystals

    International Nuclear Information System (INIS)

    Andriamonje, S.; Dural, J.; Toulemonde, M.; Groeneveld, K.O.; Maier, R.; Quere, Y.

    1990-01-01

    The interaction of moving ions with single crystals is very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. The experiments show that high energy heavy ion channeling deeply modifies the slowing down and charge exchange processes. In this review, we describe the opportunity offered by channeling conditions to study the charge exchange processes. Some aspects of the charge exchange processes with high energy channeled heavy ions are selected from the extensive literature published over the past few years on this subject. Special attention is given to the work performed at the GANIL facility on the study of Radiative Electron Capture (REG), Electron Impact Ionisation (EII), and convoy electron emission. Finally we emphasize the interest of studying resonant charge exchange processes such as Resonant Coherent Excitation (RCE), Resonant Transfer and Excitation (RTE) or Dielectronic Recombination (DR) and the recently proposed Nuclear Excitation by Electron Capture (NEEC)

  14. Comparative charge-exchange mass spectrometric and argon-sensitized radiolytic studies on methanol

    International Nuclear Information System (INIS)

    Jonsson, B.-O.; Lind, J.

    1976-01-01

    It is shown that the formation of CO and CH 4 in the argon-sensitized γ-radiolysis of methanol is dependent on a mechanism of charge exchange with the species Ar + . On the other hand, the ion Ar + 2 formed from Ar* is of minor importance. The formation of CH + 3 from methanol after charge exchange with Ar + is a rapid process, taking about 10 -13 s. (author)

  15. Possible anisotropy of the angular distribution of charge-exchange fast neutrals wall

    Energy Technology Data Exchange (ETDEWEB)

    Gulin, M.A.; Zhdanov, S.K.; Kurnaev, V.A.

    Angular distribution of neutrals is analytically investigated for estimation of the effects accompanying the interaction of charge-exchange fast neutrals with the first wall of thermonuclear devices. The results of calculations of angular distributions of fast charge-exchange neutrals at the plasma boundary for different conditions characteristic of large tokamaks are presented. The applied model gives an isotropic angular distribution with a most probable angle of incidence differing from the normal one.

  16. Antineutrino Monitoring of Spent Nuclear Fuel

    Science.gov (United States)

    Brdar, Vedran; Huber, Patrick; Kopp, Joachim

    2017-11-01

    Military and civilian applications of nuclear energy have left a significant amount of spent nuclear fuel over the past 70 years. Currently, in many countries worldwide, the use of nuclear energy is on the rise. Therefore, the management of highly radioactive nuclear waste is a pressing issue. In this paper, we explore antineutrino detectors as a tool for monitoring and safeguarding nuclear-waste material. We compute the flux and spectrum of antineutrinos emitted by spent nuclear fuel elements as a function of time, and we illustrate the usefulness of antineutrino detectors in several benchmark scenarios. In particular, we demonstrate how a measurement of the antineutrino flux can help to reverify the contents of a dry storage cask in case the monitoring chain by conventional means gets disrupted. We then comment on the usefulness of antineutrino detectors at long-term storage facilities such as Yucca mountain. Finally, we put forward antineutrino detection as a tool in locating underground "hot spots" in contaminated areas such as the Hanford site in Washington state.

  17. Design and operation of the pellet charge exchange diagnostic for measurement of energetic confined alphas and tritons on TFTR

    International Nuclear Information System (INIS)

    Medley, S.S.; Duong, H.H.

    1996-05-01

    Radially-resolved energy and density distributions of the energetic confined alpha particles in D-T experiments on TFTR are being measured by active neutral particle analysis using low-Z impurity pellet injection. When injected into a high temperature plasma, an impurity pellet (e.g. Lithium or Boron) rapidly ablates forming an elongated cloud which is aligned with the magnetic field and moves with the pellet. This ablation cloud provides a dense target with which the alpha particles produced in D-T fusion reactions can charge exchange. A small fraction of the alpha particles incident on the pellet ablation cloud will be converted to helium neutrals whose energy is essentially unchanged by the charge transfer process. By measuring the resultant helium neutrals escaping from the plasma using a mass and energy resolving charge exchange analyzer, this technique offers a direct measurement of the energy distribution of the incident high-energy alpha particles. Other energetic ion species can be detected as well, such as tritons generated in D-D plasmas and H or He 3 RF-driven minority ion tails. The diagnostic technique and its application on TFTR are described in detail

  18. Measurement of the $\\bar{p}p \\rightarrow \\bar{n}n$ Charge-Exchange Differential Cross-Section

    CERN Multimedia

    2002-01-01

    The aim of this proposal is a measurement of the differential cross-section of the $\\bar{p}$p $\\rightarrow$ $\\bar{n}$n charge-exchange reaction with a point-to-point precision of 1\\% in the forward direction, and an absolute normalization error of 3\\%. The high precision of the data should allow, inter alia, a determination of the $\\pi$NN coupling constant to better than 2\\%.\\\\ \\\\ The measurement will be done using the existing neutron and antineutron detectors built for experiment PS199 and liquid hydrogen target. In one week of running time, with a $\\bar{p}$ beam intensity of 3 $ 10 ^{5} $ $\\bar{p}$/sec, the reaction will be measured at a few $\\bar{p}$ momenta, in the range 500 to 900~MeV/c.

  19. Workshop applied antineutrino physics 2007

    International Nuclear Information System (INIS)

    Akiri, T.; Andrieu, B.; Anjos, J.; Argyriades, J.; Barouch, G.; Bernstein, A.; Bersillon, O.; Besida, O.; Bowden, N.; Cabrera, A.; Calmet, D.; Collar, J.; Cribier, M.; Kerret, H. de; Meijer, R. de; Dudziak, F.; Enomoto, S.; Fallot, M.; Fioni, G.; Fiorentini, G.; Gale, Ph.; Georgadze, A.; Giot, L.; Gonin, M.; Guillon, B.; Henson, C.; Jonkmans, G.; Kanamaru, S.; Kawasaki, T.; Kornoukhov, V.; Lasserre, Th.; Learned, J.G.; Lefebvre, J.; Letourneau, A.; Lhillier, D.; Lindner, M.; Lund, J.; Mantovani, F.; Mcdonough, B.; Mention, G.; Monteith, A.; Motta, D.; Mueller, Th.; Oberauer, L.; Obolensky, M.; Odrzywolek, A.; Petcov, S.; Porta, A.; Queval, R.; Reinhold, B.; Reyna, D.; Ridikas, D.; Sadler, L.; Schoenert, St.; Sida, J.L.; Sinev, V.; Suekane, F.; Suvorov, Y.; Svoboda, R.; Tang, A.; Tolich, N.; Tolich, K.; Vanka, S.; Vignaud, D.; Volpe, Ch.; Wong, H.

    2007-01-01

    The 'Applied Antineutrino Physics 2007' workshop is the fourth international meeting devoted to the opening of the neutrino physics to more applied fields, such as geophysics and geochemistry, nuclear industry, as well as the nonproliferation. This meeting highlights the world efforts already engaged to exploit the single characteristics of the neutrinos for the control of the production of plutonium in the civil nuclear power reactor. The potential industrial application of the measurement of the thermal power of the nuclear plants by the neutrinos is also approached. earth neutrinos were for the first time highlighted in 2002 by the KamLAND experiment. Several international efforts are currently underway to use earth neutrinos to reveal the interior of the Earth. This meeting is an opportunity to adapt the efforts of detection to the real needs of geophysicists and geochemists (sources of radiogenic heat, potassium in the court, feathers.) Finally more futuristic topics such as the detection of nuclear explosions, of low powers, are also discussed. This document gathers only the slides of the presentations

  20. Workshop applied antineutrino physics 2007

    Energy Technology Data Exchange (ETDEWEB)

    Akiri, T.; Andrieu, B.; Anjos, J.; Argyriades, J.; Barouch, G.; Bernstein, A.; Bersillon, O.; Besida, O.; Bowden, N.; Cabrera, A.; Calmet, D.; Collar, J.; Cribier, M.; Kerret, H. de; Meijer, R. de; Dudziak, F.; Enomoto, S.; Fallot, M.; Fioni, G.; Fiorentini, G.; Gale, Ph.; Georgadze, A.; Giot, L.; Gonin, M.; Guillon, B.; Henson, C.; Jonkmans, G.; Kanamaru, S.; Kawasaki, T.; Kornoukhov, V.; Lasserre, Th.; Learned, J.G.; Lefebvre, J.; Letourneau, A.; Lhillier, D.; Lindner, M.; Lund, J.; Mantovani, F.; Mcdonough, B.; Mention, G.; Monteith, A.; Motta, D.; Mueller, Th.; Oberauer, L.; Obolensky, M.; Odrzywolek, A.; Petcov, S.; Porta, A.; Queval, R.; Reinhold, B.; Reyna, D.; Ridikas, D.; Sadler, L.; Schoenert, St.; Sida, J.L.; Sinev, V.; Suekane, F.; Suvorov, Y.; Svoboda, R.; Tang, A.; Tolich, N.; Tolich, K.; Vanka, S.; Vignaud, D.; Volpe, Ch.; Wong, H

    2007-07-01

    The 'Applied Antineutrino Physics 2007' workshop is the fourth international meeting devoted to the opening of the neutrino physics to more applied fields, such as geophysics and geochemistry, nuclear industry, as well as the nonproliferation. This meeting highlights the world efforts already engaged to exploit the single characteristics of the neutrinos for the control of the production of plutonium in the civil nuclear power reactor. The potential industrial application of the measurement of the thermal power of the nuclear plants by the neutrinos is also approached. earth neutrinos were for the first time highlighted in 2002 by the KamLAND experiment. Several international efforts are currently underway to use earth neutrinos to reveal the interior of the Earth. This meeting is an opportunity to adapt the efforts of detection to the real needs of geophysicists and geochemists (sources of radiogenic heat, potassium in the court, feathers.) Finally more futuristic topics such as the detection of nuclear explosions, of low powers, are also discussed. This document gathers only the slides of the presentations.

  1. Laboratory Measurements Of Charge-exchange Produced X-ray Emission From K-shell Transitions In Hydrogenic And Helium-like Fe

    Science.gov (United States)

    Brown, Gregory V.; Beiersdorfer, P.; Boyce, K. R.; Chen, H.; Gu, M. F.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Thorn, D.; Wargelin, B.

    2006-09-01

    We have used a microcalorimeter and solid state detectors to measure x-ray emission produced by charge exchange reactions between bare and hydrogenic Fe colliding with neutral helium, hydrogen, and nitrogen gas. We show the measured spectral signature produced by different neutral donors and compare our results to theory where available. We also compare our results to measurements of the Fe K line emission from the Galactic Center measured by the XIS on the Suzaku x-ray observatory. This comparison shows that charge exchange recombination between highly charged ions (either cosmic rays or thermal ions) and neutral gas is probably not the dominant source of diffuse line emission in the Galactic Center. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48, and is also supported by NASA APRA grants to LLNL, GSFC, Harvard-Smithsonian CfA, and Stanford University.

  2. Daya Bay Antineutrino Detector gas system

    Science.gov (United States)

    Band, H. R.; Cherwinka, J. J.; Chu, M.-C.; Heeger, K. M.; Kwok, M. W.; Shih, K.; Wise, T.; Xiao, Q.

    2012-11-01

    The Daya Bay Antineutrino Detector gas system is designed to protect the liquid scintillator targets of the antineutrino detectors against degradation and contamination from exposure to ambient laboratory air. The gas system is also used to monitor the leak tightness of the antineutrino detector assembly. The cover gas system constantly flushes the gas volumes above the liquid scintillator with dry nitrogen to minimize oxidation of the scintillator over the five year lifetime of the experiment. This constant flush also prevents the infiltration of radon or other contaminants into these detecting liquids keeping the internal backgrounds low. Since the Daya Bay antineutrino detectors are immersed in the large water pools of the muon veto system, other gas volumes are needed to protect vital detector cables or gas lines. These volumes are also purged with dry gas. Return gas is monitored for oxygen content and humidity to provide early warning of potentially damaging leaks. The design and performance of the Daya Bay Antineutrino Detector gas system is described.

  3. A Direction-Sensitive Detector for Electron Antineutrinos

    Science.gov (United States)

    Brooks, F. D.; Drosg, M.; Smit, F. D.

    2011-12-01

    A modular design is proposed for an electron antineutrino detector based on boron-doped liquid scintillator. Tests have been carried out on small detector systems using neutrons to simulate the antineutrino detection signature. Results from these tests are reported, and the possibility of using a larger system of similar design to detect reactor antineutrinos is discussed.

  4. Applied Anti-neutrino Physics 2013

    CERN Document Server

    2013-01-01

    This year, the 9th annual Applied Antineutrino Physics Workshop will be hosted by Sejong University, at the COEX conference center in Seoul South Korea. The workshop will be held on November 1(Friday) - 2(Saturday), 2013. Conveniently for many travelers, it takes place directly after and at the same venue as the 2013 IEEE Nuclear Science Symposium (http://www.nss-mic.org/2013/NSSMain.asp) Applied Antineutrino Physics describes an ensemble of experimental and theoretical efforts which aim to use the antineutrino signal from nuclear reactors, and from the Earth itself, in order to address practical problems in nonproliferation and geology respectively. Since the 2004 inception of these workshops, groups worldwide have made considerable advances in defining and expanding the field, garnering interest from the International Atomic Energy Agency (IAEA), which administers the worlds most important nonproliferation regime, and from the geology/geophysics community. This meeting will focus on the current activi...

  5. X-ray Signature of Charge Exchange in the Spectra of L-shell Iron Ions

    Energy Technology Data Exchange (ETDEWEB)

    Beiersdorfer, P; Schweikhard, L; Liebisch, P; Brown, G V

    2007-01-05

    The X-ray signature of charge exchange between highly charged L-shell iron ions and neutral gas atoms was studied in the laboratory in order to assess its diagnostic utility. Significant differences with spectra formed by electron-impact excitation were observed. In particular, a strong enhancement was found of the emission corresponding to n {le} 4 {yields} n = 2 transitions relative to the n = 3 {yields} n = 2 emission. This enhancement was detectable even with relatively low-resolution X-ray instrumentation (E/{Delta}E {approx} 10) and may enable future identification of charge exchange as a line-formation mechanism in astrophysical spectra.

  6. Anti-neutrino disintegration of the deuteron

    International Nuclear Information System (INIS)

    Mueller, W.; Gari, M.; Max-Planck-Institut fuer Chemie

    1981-01-01

    The anti-neutrino disintegration of the deuteron (anti ν + D → anti ν + n + p and anti νsub(e) + D → + e + + n + n) is calculated using realistic two-body states. Meson-exchange currents are considered in the one-boson-exchange limit. The results are discussed as corrections to the cross sections obtained in effective range approximations. It is shown that the ratio of the cross sections (sigma - /sigma 0 ) for reactor antineutrinos is practically independent of the nuclear physics uncertainties. (orig.)

  7. Antineutrino-nucleon total cross section and ratio of antineutrino cross section on neutrons and protons

    CERN Document Server

    Erriquez, O; Bisi, V; Bonetti, S; Bullock, F W; Cavalli, D; Engel, J P; Eranzinetti, C; Escubes, B; Esten, M J; Fogli-Muciaccia, M T; Gamba, D; Guyonnet, J L; Halsteinslid, A; Henderson, R C W; Huss, D; Jones, T W; Marzari-Chiesa, A; Mauri, F; Myklebost, K; Natali, S; Nuzzo, S; Paty, M; Pullia, A; Racca, C; Ramzan, F A; Riccati, L; Riester, J L; Rognebakke, A; Rollier, M; Romero, A; Skjeggestad, O

    1979-01-01

    On a selected sample of 2171 events, observed in the heavy liquid bubble chamber Gargamelle at CERN, the charged current total cross section for antineutrino on nucleons has been determined to the laboratory energy 8 GeV. (7 refs).

  8. π--induced single charge exchange on polarized 3He

    International Nuclear Information System (INIS)

    Zhao, Q.; Burleson, S.; Blanchard, T.

    1995-01-01

    Asymmetries, A y , for the (π - ,π 0 ) reaction on polarized 3 He were measured using the pion beam of the P3W channel at LAMPF. The π 0 were detected with the new Neutral Meson Spectrometer (NMS) in coincidence with recoiling tritons. The recoil detector consisted of scintillation-counter telescopes and a wire chamber that provided energy-loss and direction information, respectively. The polarized gaseous 3 He target developed at TRIUMF was modified and run with the use of two diode lasers. Polarizations were typically 50%. The A y taken at T π = 200 MeV between 60 and 105 degrees were found to be strongly angle-dependent. The results will be compared with the theoretical predictions

  9. High spatial and temporal resolution charge exchange recombination spectroscopy on the HL-2A tokamak

    NARCIS (Netherlands)

    Wei, Y. L.; Yu, D. L.; Liu, L.; Ida, K.; von Hellermann, M.; Cao, J. Y.; Sun, A. P.; Ma, Q.; Chen, W. J.; Liu, Yi; Yan, L. W.; Yang, Q. W.; Duan, X. R.; Liu, Yong

    2014-01-01

    A 32/64-channel charge exchange recombination spectroscopy (CXRS) diagnostic system is developed on the HL-2A tokamak (R = 1.65 m, a = 0.4 m), monitoring plasma ion temperature and toroidal rotation velocity simultaneously. A high throughput spectrometer (F/2.8) and a pitch-controlled fiber bundle

  10. Performance study of the TFTR diagnostic neutral beam for active charge exchange measurements

    International Nuclear Information System (INIS)

    Medley, S.S.; Goldston, R.J.; Towner, H.H.

    1980-06-01

    A neutral beam source will be incorporated in the Tokamak Fusion Test Reactor (TFTR) charge exchange diagnostic to provide a time modulated, spatially localized enhancement of the charge exchange efflux. Two autonomous Charge Exchange Neutral Analyzer (CENA) systems are being designed for the TFTR. One system measures the plasma ion temperature along twelve vertical line-of-sight chords spaced approximately equidistantly across the torus minor diameter. The other system is dedicated primarily to measurement of ion phenomena associated with neutral beam injection heating and has a fan-like field of view along eight sight-lines in the equitorial plane. The neutral beam is steerable in order to access the viewing field of both CENA systems, though in general not simultaneously. The performance of the diagnostic neutral beam is evaluated to determine the optimal beam specifications for active charge exchange measurements. Using the optimal beam design parameters, the efficacy of the neutral doping is examined for both CENA systems over the envisioned range of the TFTR plasma density and temperature

  11. Lattice Issues of the CERN PSB with H- Charge exchange injection hardware

    CERN Document Server

    Aiba, M; Chanel, M; Goddard, B; Martini, M; Weterings, W

    2010-01-01

    The motivation for the construction of CERN Linac4 is to improve the performance of the PSB by raising the injection energy and implementing a new H- charge exchange multiturn injection scheme. Lattice perturbations introduced by the new injection hardware are described. Strategies to mitigate the consequences, first by minimizing the additional focusing introduced and, by compensating the residual perturbation, are reported.

  12. Conceptual design of the ITER upper port plug for charge exchange diagnostic

    NARCIS (Netherlands)

    Sadakov, S.; Baross, T.; Biel, W.; Borsuk, V.; Hawkes, N.; Hellermann, M. von; Gille, P.; Kiss, G.; Koning, J.; Knaup, M.; Klinkhamer, J.F.F.; Krasikov, Yu.; Litnovsky, A.; Neubauer, O.; Panin, A.

    2009-01-01

    A plug for the ITER core charge exchange recombination spectroscopy (core CXRS) is located in the upper port 3. It transfers the light emitted by interaction of plasma ions with the diagnostic neutral beam (DNB). The plug consists of a main shell, a shielding cassette and a retractable tube. The

  13. Present and Future Experiments in Non-equilibrium Reactor Antineutrino Energy Spectrum

    OpenAIRE

    Kopeikin, V. I.; Mikaelyan, L. A.

    2005-01-01

    Considerable efforts that have been undertaken in the recent years in low energy antineutrino experiments require further systematic investigations in line of reactor antineutrino spectroscopy as a metrological basis of these experiments. We consider some effects associated with the non-equilibrium of reactor antineutrino radiation and residual antineutrino emission from spent reactor fuel in contemporary antineutrino experiments.

  14. Total cross sections for pion charge exchange on the proton

    Energy Technology Data Exchange (ETDEWEB)

    Breitschopf, J.

    2006-04-28

    This work describes the measurement of total SCX cross sections employing a new 4{pi} scintillation counter to perform transmission measurements in the incident pion energy range from about 38 to 250 MeV. A small 4{pi} detector box consisting of thin plastic scintillators has been constructed. The transmission technique, which was used, relates the number of transmitted charged pions to that of incident beam pions and this way effectively counts events with neutral products. The incoming negative pions were counted by three beam defining counters before they hit a target of very well known size and chemical composition. The target was placed in the box detector which was not sensitive to the neutral particles resulting from the SCX. The total cross section for emerging neutral particles was derived from the comparison of the numbers of the incoming and transmitted charged particles. The total SCX cross section on hydrogen was derived from the transmissions of a CH{sub 2} target, a carbon target and an empty target. For a detailed offline analysis all TDC, QDC and FADC information was recorded in an event by event mode for each triggered beam event. Various corrections had to be applied to the data, such as random correction, the detection of neutrals in the detector, Dalitz decay, pion decay and the radiative pion capture. This measurement covers, as the only experiment, the whole {delta}-resonance and the sp-interference region in one single experimental setup and improves the available data base for the SCX reaction. It is shown that the description of the SCX cross sections is improved if the s-wave amplitudes, that have been fixed essentially by elastic pion-nucleon scattering data, is reduced by (4{+-}1.5)%. The exact value depends on the SCX literature data included and on the parameters of the {delta}{sup 0} Breit-Wigner resonance describing the p{sub 33}-waves. This shows that p-wave as well as s-wave effects should be considered in studies of isospin

  15. Total cross sections for pion charge exchange on the proton

    International Nuclear Information System (INIS)

    Breitschopf, J.

    2006-01-01

    This work describes the measurement of total SCX cross sections employing a new 4π scintillation counter to perform transmission measurements in the incident pion energy range from about 38 to 250 MeV. A small 4π detector box consisting of thin plastic scintillators has been constructed. The transmission technique, which was used, relates the number of transmitted charged pions to that of incident beam pions and this way effectively counts events with neutral products. The incoming negative pions were counted by three beam defining counters before they hit a target of very well known size and chemical composition. The target was placed in the box detector which was not sensitive to the neutral particles resulting from the SCX. The total cross section for emerging neutral particles was derived from the comparison of the numbers of the incoming and transmitted charged particles. The total SCX cross section on hydrogen was derived from the transmissions of a CH 2 target, a carbon target and an empty target. For a detailed offline analysis all TDC, QDC and FADC information was recorded in an event by event mode for each triggered beam event. Various corrections had to be applied to the data, such as random correction, the detection of neutrals in the detector, Dalitz decay, pion decay and the radiative pion capture. This measurement covers, as the only experiment, the whole Δ-resonance and the sp-interference region in one single experimental setup and improves the available data base for the SCX reaction. It is shown that the description of the SCX cross sections is improved if the s-wave amplitudes, that have been fixed essentially by elastic pion-nucleon scattering data, is reduced by (4±1.5)%. The exact value depends on the SCX literature data included and on the parameters of the Δ 0 Breit-Wigner resonance describing the p 33 -waves. This shows that p-wave as well as s-wave effects should be considered in studies of isospin symmetry breaking. Interestingly

  16. Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay.

    Science.gov (United States)

    An, F P; Balantekin, A B; Band, H R; Bishai, M; Blyth, S; Butorov, I; Cao, D; Cao, G F; Cao, J; Cen, W R; Chan, Y L; Chang, J F; Chang, L C; Chang, Y; Chen, H S; Chen, Q Y; Chen, S M; Chen, Y X; Chen, Y; Cheng, J H; Cheng, J; Cheng, Y P; Cherwinka, J J; Chu, M C; Cummings, J P; de Arcos, J; Deng, Z Y; Ding, X F; Ding, Y Y; Diwan, M V; Dove, J; Draeger, E; Dwyer, D A; Edwards, W R; Ely, S R; Gill, R; Gonchar, M; Gong, G H; Gong, H; Grassi, M; Gu, W Q; Guan, M Y; Guo, L; Guo, X H; Hackenburg, R W; Han, R; Hans, S; He, M; Heeger, K M; Heng, Y K; Higuera, A; Hor, Y K; Hsiung, Y B; Hu, B Z; Hu, L M; Hu, L J; Hu, T; Hu, W; Huang, E C; Huang, H X; Huang, X T; Huber, P; Hussain, G; Jaffe, D E; Jaffke, P; Jen, K L; Jetter, S; Ji, X P; Ji, X L; Jiao, J B; Johnson, R A; Kang, L; Kettell, S H; Kohn, S; Kramer, M; Kwan, K K; Kwok, M W; Kwok, T; Langford, T J; Lau, K; Lebanowski, L; Lee, J; Lei, R T; Leitner, R; Leung, K Y; Leung, J K C; Lewis, C A; Li, D J; Li, F; Li, G S; Li, Q J; Li, S C; Li, W D; Li, X N; Li, X Q; Li, Y F; Li, Z B; Liang, H; Lin, C J; Lin, G L; Lin, P Y; Lin, S K; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, D W; Liu, H; Liu, J L; Liu, J C; Liu, S S; Lu, C; Lu, H Q; Lu, J S; Luk, K B; Ma, Q M; Ma, X Y; Ma, X B; Ma, Y Q; Martinez Caicedo, D A; McDonald, K T; McKeown, R D; Meng, Y; Mitchell, I; Monari Kebwaro, J; Nakajima, Y; Napolitano, J; Naumov, D; Naumova, E; Ngai, H Y; Ning, Z; Ochoa-Ricoux, J P; Olshevski, A; Pan, H-R; Park, J; Patton, S; Pec, V; Peng, J C; Piilonen, L E; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Raper, N; Ren, B; Ren, J; Rosero, R; Roskovec, B; Ruan, X C; Shao, B B; Steiner, H; Sun, G X; Sun, J L; Tang, W; Taychenachev, D; Tsang, K V; Tull, C E; Tung, Y C; Viaux, N; Viren, B; Vorobel, V; Wang, C H; Wang, M; Wang, N Y; Wang, R G; Wang, W; Wang, W W; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Wei, H Y; Wen, L J; Whisnant, K; White, C G; Whitehead, L; Wise, T; Wong, H L H; Wong, S C F; Worcester, E; Wu, Q; Xia, D M; Xia, J K; Xia, X; Xing, Z Z; Xu, J Y; Xu, J L; Xu, J; Xu, Y; Xue, T; Yan, J; Yang, C G; Yang, L; Yang, M S; Yang, M T; Ye, M; Yeh, M; Young, B L; Yu, G Y; Yu, Z Y; Zang, S L; Zhan, L; Zhang, C; Zhang, H H; Zhang, J W; Zhang, Q M; Zhang, Y M; Zhang, Y X; Zhang, Y M; Zhang, Z J; Zhang, Z Y; Zhang, Z P; Zhao, J; Zhao, Q W; Zhao, Y F; Zhao, Y B; Zheng, L; Zhong, W L; Zhou, L; Zhou, N; Zhuang, H L; Zou, J H

    2016-02-12

    This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18)  cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43)  cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) relative to the flux predicted with the Huber-Mueller (ILL-Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.

  17. Laboratory Studies of X-ray Spectra Formed by Charge Exchange

    Science.gov (United States)

    Beiersdorfer, Peter; Ali, R.; Brown, G. V.; Koutroumpa, D.; Kelley, R. L.; Kilbourne, C.; Leutenegger, M. A.; Porter, F.

    2013-04-01

    Charge exchange between ions and neutral atoms or molecules has been accepted at an important soft producing process in our solar system. By extension, charge exchange may contribute to the X-ray emission of circumstellar material. It may also produce X-ray emission at the boundaries of supernova ejecta and star burst galaxies, or whenever hot plasma collides with neutral matter. X-ray spectra of K-shell and L-shell ions formed by charge exchange have now been studied in a variety of laboratory settings. These experiments have shown several characteristic features of line formation by charge exchange when compared to the X-ray emission produced by electron-impact excitation, e.g., enhancement emission of forbidden lines and of lines from levels with high principal quantum number. They have also shown a dependence on the interaction gas and on the energy of the ion-neutral collision. Moreover, the transfer of multiple electrons is typically preferred, provided the donor molecules or atoms have multiple valence-shell electrons. The laboratory measurements are in qualitative agreement with theory. However, the details of the observed X-ray spectra, especially those recorded with high spectral resolution, can differ substantially from predictions, especially for spectra produced at collision velocities equal to or lower than those found in thermal plasmas or produced with neutral gases other than atomic hydrogen. Puzzling discrepancies can be noted, such as enhanced emission from an upper level with the 'wrong' principal quantum number. Even more puzzling is a recent experiment in which two, co-mixed bare ion species of similar atomic number produce very different Lyman series emission upon charge exchange with a given neutral gas, defying both theoretical predictions and empirical scaling. Laboratory measurements have also shown that some of the characteristic features of charge exchange can be reproduced by radiative electron capture, i.e., by capture of a continuum

  18. Antineutrino flux and spectrum calculation for spent nuclear fuel for the Daya Bay antineutrino experiment

    Science.gov (United States)

    Ma, X. B.; Zhao, Y. F.; Chen, Y. X.; Zhong, W. L.; An, F. P.

    2017-10-01

    The antineutrino flux from spent nuclear fuel (SNF) is an important source of uncertainty when making estimates of a reactor neutrino flux. However, to determine the contribution from SNF, sufficient data is needed such as the amount of spent fuel in the pool, the time after discharged from the reactor core, the burnup of each assembly, and the antineutrino spectrum of each isotope in the SNF. A method to calculate this contribution is proposed. A reactor simulation code verified against experimental data has been used to simulate fuel depletion by taking into account more than 2000 isotopes and fission products, the quantity of SNF in each of the six spent fuel pools, and the time variation of the antineutrino spectra after SNF discharging from the core. Results show that the SNF contribution to the total antineutrino flux is about 0.26%-0.34%, and the shutdown impact is about 20%. The SNF spectrum alters the softer part of the antineutrino spectra, and the maximum contribution from the SNF is about 3.0%. Nevertheless, there is an 18% difference between the line evaluate method and under evaluate method. In addition, non-equilibrium effects are also discussed, and the results are compatible considering the uncertainties.

  19. Bounds on the g/sub K//sub N//sub Σ/ 2 coupling constant from positivity and charge-exchange data

    International Nuclear Information System (INIS)

    Antolin, J.

    1987-01-01

    Positivity of the imaginary part of the forward K - n elastic amplitude on the unphysical cut allows the calculation of bounds on the g/sub K//sub N//sub Σ/ 2 coupling constant using the forward differential cross sections of the charge-exchange reaction K - p→K-bar 0 n, the scarce K - n real-part data, and a Stieltjes parametrization of the K - p real-part data. The bounds on the coupling constant are 2.11 2 - n amplitude: (0.35 +- 0.05) +- (0.16 +- 0.04)i GeV/c

  20. ROSAT Observations of Solar Wind Charge Exchange with the Lunar Exosphere

    Science.gov (United States)

    Collier, Michael R.; Snowden, S. L.; Benna, M.; Carter, J. A.; Cravens, T. E.; Hills, H. Kent; Hodges, R. R.; Kuntz, K. D.; Porter, F. Scott; Read, A.; hide

    2012-01-01

    We analyze the ROSAT PSPC soft X-ray image of the Moon taken on 29 June 1990 by examining the radial profile of the count rate in three wedges, two wedges (one north and one south) 13-32 degrees off (19 degrees wide) the terminator towards the dark side and one wedge 38 degrees wide centered on the anti-solar direction. The radial profiles of both the north and the south wedges show substantial limb brightening that is absent in the 38 degree wide antisolar wedge. An analysis of the count rate increase associated with the limb brightening shows that its magnitude is consistent with that expected due to solar wind charge exchange (SWCX) with the tenuous lunar atmosphere. Along with Mars, Venus, and Earth, the Moon represents another solar system body at which solar wind charge exchange has been observed. This technique can be used to explore the solar wind-lunar interaction.

  1. Metastable Cadmium (53P1) production in the Cd+-Na charge-exchange collision

    International Nuclear Information System (INIS)

    Coelho, L.F.

    1987-01-01

    The 326.1 nm emission cross section for the collision process Cd + +Na -> Cd(5 3 P 1 ) + Na + was measured in the energy range 1.5-4.9 KeV. It decreases monotonically from 5 to 2x10 -15 cm 2 . Due to a near degeneracy in energy, this channel presents a much larges cross section than all others (except 5 3 P 0 and 5 3 P 2 , which are highly metastable). This justifies the neglect of the cascade mechanism for populating the 5 3 P 1 , state and, consequently, allows the identification of the 326.1 nm emission cross section with the 5 3 P 1 charge-exchanger excitation cross section. The measured values agree well with theoretical estimates obtained with Olson's model for near-resonant charge exchange. (author) [pt

  2. Charge-exchange recombination spectroscopy measurements of ion temperature and plasma rotation in PBX

    International Nuclear Information System (INIS)

    Jaehnig, K.P.; Fonck, R.J.; Ida, K.; Powell, E.T.

    1984-11-01

    The primary diagnostic on PBX for ion temperature measurements is charge-exchange recombination spectroscopy of low Z ions, wherein fast neutrals from the heating neutral beams excite spectral lines from highly excited states (n greater than or equal to 4) of hydrogenic 0, C, and He via charge-exchange collisions with the respective fully stripped ions. Since the neutral beams on PBX provide relatively low velocity neutrals (i.e., D 0 beams at 44 keV), the best signals are obtained using the near-uv lines of 0 7+ (e.g., n = 8-7, 2976 A). Off-line analysis of the Doppler broadened and shifted line profiles includes non-linear least squares fitting to a model line profile, while a simplified on-line fast analysis code permits between-shot data analysis

  3. Low-energy pion double charge exchange and nucleon-nucleon correlations in nuclei

    International Nuclear Information System (INIS)

    Leitch, M.J.

    1989-01-01

    Recent measurements of pion double-charge exchange (DCX) at energies 20 to 70 MeV are providing a new means for studying nucleon-nucleon correlations in nuclei. At these energies the nucleus is relatively transparent, allowing simpler theoretical models to be used in interpreting the data and leading to a clearer picture. Also the contribution to DCX of sequential charge-exchange scattering through the intermediate analog state is suppressed near 50 MeV and transitions through non-analog intermediate states become very important. Recent theoretical studies by several groups have shown that while transitions through the analog route involve relatively long nucleon-nucleon distances, those through non-analog intermediate states obtain nearly half their strength from nucleon pairs with less than 1 fermi separation. Thus DCX near 50 MeV is an excellent way to study short-range nucleon-nucleon correlations. 31 refs., 29 figs., 4 tabs

  4. Low-energy pion double charge exchange and nucleon-nucleon correlations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leitch, M.J.

    1989-01-01

    Recent measurements of pion double-charge exchange (DCX) at energies 20 to 70 MeV are providing a new means for studying nucleon-nucleon correlations in nuclei. At these energies the nucleus is relatively transparent, allowing simpler theoretical models to be used in interpreting the data and leading to a clearer picture. Also the contribution to DCX of sequential charge-exchange scattering through the intermediate analog state is suppressed near 50 MeV and transitions through non-analog intermediate states become very important. Recent theoretical studies by several groups have shown that while transitions through the analog route involve relatively long nucleon-nucleon distances, those through non-analog intermediate states obtain nearly half their strength from nucleon pairs with less than 1 fermi separation. Thus DCX near 50 MeV is an excellent way to study short-range nucleon-nucleon correlations. 31 refs., 29 figs., 4 tabs.

  5. Charge-Exchange Neutral Particle Analyzer Diagnostic of TJ-II

    International Nuclear Information System (INIS)

    Fontdecaba, J.M.; Balbin, R.; Petrov, S.; TJ-II team

    2003-01-01

    A description of the Charge Exchange Neutral Particle Analyzers in operation in the heliac flexible TJ-II is reported. A description of the detectors, as well as the operation characteristics, hardware and software used in the control and analysis of the data obtained with the diagnostic is detailed. Two NPAs are in operation in TJ-II. One of them is a 5-channel analyzer and another one is an Acord-12. The 5-channel analyzer provides measurements of charge exchange neutral fluxes at five energy channels, whereas the Acord-12 can measure simultaneously two different hydrogen isotopes (H and D) at six energy channels. Their lines of sight can be varied poloidally in order to observe the different sections of the plasma. (Author) 10 refs

  6. Charge-Exchange Neutral Particle Analyzer Diagnostic of TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Fontdecaba, J. M.; Balbin, R.; Petrov, S.; TJ-II team

    2003-07-01

    A description of the Charge Exchange Neutral Particle Analyzers in operation in the heliac flexible TJ-II is reported. A description of the detectors, as well as the operation characteristics, hardware and software used in the control and analysis of the data obtained with the diagnostic is detailed. Two NPAs are in operation in TJ-II. One of them is a 5-channel analyzer and another one is an Acord-12. The 5-channel analyzer provides measurements of charge exchange neutral fluxes at five energy channels, whereas the Acord-12 can measure simultaneously two different hydrogen isotopes (H and D) at six energy channels. Their lines of sight can be varied poloidally in order to observe the different sections of the plasma. (Author) 10 refs.

  7. Measurement on the emission of charge exchange recombination in HT-6M tokamak

    International Nuclear Information System (INIS)

    Xu Wei; Wan Baonian

    1999-01-01

    The distribution of C VI line (at 207.1 nm) and the time behavior has been measured with Optical Spectroscope Multichannel Analyzer and single channel near ultra-violet system in HT-6M Tokamak. The result of the analysis of line shape and the time behavior show that C VI line (at 207.1 nm) stemmed from the emission of charge exchange recombination processes

  8. Charge exchange signatures in x-ray line emission accompanying plasma-wall interaction

    Czech Academy of Sciences Publication Activity Database

    Renner, Oldřich; Dalimier, E.; Liska, R.; Oks, E.; Šmíd, Michal

    2012-01-01

    Roč. 397, č. 1 (2012), s. 1-6 ISSN 1742-6588 R&D Projects: GA ČR GAP205/10/0814; GA ČR GAP208/10/2302; GA AV ČR IAAX00100903 Institutional research plan: CEZ:AV0Z10100523 Keywords : laser-produced plasma * particle jets generation * plasma-wall interaction * x-ray spectroscopy * charge exchange Subject RIV: BL - Plasma and Gas Discharge Physics

  9. Study of proton polarization in charge exchange process on optically oriented sodium atoms

    International Nuclear Information System (INIS)

    Zelenskij, A.N.; Kokhanovskij, S.A.

    1984-01-01

    Using high-power adjustable dye lasers for electron spin orientation in a charge-exchange target enables to significantly increase the proton polarization efficiency. A device is described that permits to avoid growth of the polarized proton beam emittance in a charge-exchange process in a strong magnetic field. The devise main feature is the use of an intensive source of neutral hydrogen atoms and the presence of a helium additional charge-exchange target which actualy is a proton ''source''. The helium charge-exchange cell is placed in the same magnetic field of a solenoid where a cell with oriented sodium is placed, a polarized electron being captured by a proton in the latter cell. In this case the beam at the solenoid inlet and outlet is in a neutral state; emittance growth related to the effect of end magnetic fields is not observed. The device after all prouduces polarized protons, their polarization degree is measured and the effect of various factors on polarization degree is studied. The description of the laser source and laser system is given. Measurement results have shown the beam intensity of neutral 7 keV atoms which passed through a polarizer to be 2 mA. The proton current doesn't depend. On the beeld fin the region of chrge exchange for the 8 kGs magnetic field. The degree of sodium polarization was 80% and polarized proton current approximately 70 μA at a temperature of the polarized sodium cell corresponding to the density of sodium vapar approximately 3x10 13 at/cm 2

  10. Study of Charge-Exchange Neutrals Emission from Hot Plasma at the Multimirror Trap GOL-3

    International Nuclear Information System (INIS)

    Burdakov, A.V.; Derevyankin, G.E.; Koidan, V.S.; Shoshin, A.A.; Trunev, Yu.A.

    2005-01-01

    Tentative experiments on registration of the energy spectrum of fast charge exchange (CX) neutrals emitted from the high-density hot plasma of the GOL-3 facility were carried out. Experimental data provided by used 5-channel CX neutrals analyzer are presented and the procedure of determining of the energy distribution of registered CX neutrals is discussed. From calculated data of the neutrals energy distribution the estimated temperature is 1.5 ± 0.5 keV

  11. USING KAPPA FUNCTIONS TO CHARACTERIZE OUTER HELIOSPHERE PROTON DISTRIBUTIONS IN THE PRESENCE OF CHARGE-EXCHANGE

    Energy Technology Data Exchange (ETDEWEB)

    Zirnstein, E. J.; McComas, D. J., E-mail: ezirnstein@swri.edu, E-mail: dmccomas@swri.edu [Southwest Research Institute, San Antonio, TX 78228 (United States)

    2015-12-10

    Kappa functions have long been used in the analysis and modeling of suprathermal particles in various space plasmas. In situ observations of the supersonic solar wind show its distribution contains a cold ion core and power-law tail, which is well-represented by a kappa function. In situ plasma observations by Voyager, as well as observations of energetic neutral atom (ENA) spectra by the Interstellar Boundary Explorer (IBEX), showed that the compressed and heated inner heliosheath (IHS) plasma beyond the termination shock can also be represented by a kappa function. IBEX exposes the IHS plasma properties through the detection of ENAs generated by charge-exchange in the IHS. However, charge-exchange modifies the plasma as it flows through the IHS, and makes it difficult to ascertain the parent proton distribution. In this paper we investigate the evolution of proton distributions, initially represented by a kappa function, that experience losses due to charge-exchange in the IHS. In the absence of other processes, it is no longer representable by a single kappa function due to the energy-dependent, charge-exchange process. While one can still fit a kappa function to the evolving proton distribution over limited energy ranges, this yields fitting parameters (pseudo-density, pseudo-temperature, pseudo-kappa index) that depend on the energy range of the fit. We discuss the effects of fitting a kappa function to the IHS proton distribution over limited energy ranges, its dependence on the initial proton distribution properties at the termination shock, and implications for understanding the observations.

  12. Achievement of the charge exchange work diminishing of an internal combustion engine in part load

    Directory of Open Access Journals (Sweden)

    Stefan POSTRZEDNIK

    2012-01-01

    Full Text Available Internal combustion engines, used for driving of different cars, occurs not only at full load, but mostly at the part load. The relative load exchange work at the full (nominal engine load is significantly low. At the part load of the IC engine its energy efficiency ηe is significantly lower than in the optimal (nominal field range of the performance parameters. One of the numerous reasons of this effect is regular growing of the relative load exchange work of the IC engine. It is directly connected with the quantitative regulation method commonly used in the IC engines. From the thermodynamic point of view - the main reason of this effect is the throttling process (causing exergy losses occurring in the inlet and outlet channels. The known proposals for solving of this problem are based on applying of the fully electronic control of the motion of inlet, outlet valves and new reference cycles.The idea presented in the paper leads to diminishing the charge exchange work of the IC engines. The problem can be solved using presented in the paper a new concept of the reference cycle (called as eco-cycle of IC engine. The work of the engine basing on the eco-cycle occurs in two 3-stroke stages; the fresh air is delivered only once for both stages, but in range of each stage a new portion of fuel is burned. Normally the charge exchange occurs once during each engine cycle realized. Elaborated proposition bases on the elimination of chosen charge exchange processes and through this the dropping of the charge exchange work can be achieved.

  13. Antineutrino and gamma emission from the OSIRIS research reactor

    Directory of Open Access Journals (Sweden)

    Giot Lydie

    2017-01-01

    Full Text Available For the first time, the summation method has been coupled with a complete reactor model, in order to predict the antineutrino emission of a research reactor. This work, discussed in the first part of this paper, allows us to predict the low energy part of the antineutrino spectrum, evidencing the important contribution of actinides to the antineutrino emission. Experimental conditions at short distance from research reactors are challenging, because the reactor itself produces huge gamma background that induce accidental and correlated backgrounds in an antineutrino target. The understanding of this background is of utmost importance and triggered the second part of the work presented here.

  14. Signatures of the electron saddle swaps mechanism in the photon spectra following charge-exchange collisions

    Science.gov (United States)

    Otranto, Sebastian

    2014-10-01

    During the last few years, several experimental and theoretical studies have focused on state selective charge exchange processes between charged ions and alkali metals. These data are of particular importance for the tokamak nuclear fusion reactor program, since diagnostics on the plasma usually rely on charge-exchange spectroscopy. In this sense, alkali metals, have been proposed as potential alternatives to excited hydrogen/deuterium for which laboratory experiments are not feasible at present. In this talk, we present our recent work involving ion collisions with alkali metals. Oscillatory structures in the angular differential charge-exchange cross sections obtained using the MOTRIMS technique are correctly described by classical trajectory Monte Carlo simulations. These oscillations are found to originate from the number of swaps the electron undergoes around the projectile-target potential saddle before capture takes place and are very prominent at impact energies below 10 keV/amu. Moreover, cross sections of higher order of differentiability also indicate that the swaps leave distinctive signatures in the (n,l)-state selective cross sections and in the photon line emission cross sections. Oscillatory structures for the x-ray hardness ratio parameter are also predicted. In collaboration with Ronnie Hoekstra, Zernike Institute for Advanced Materials, University of Groningen and Ronald Olson, Department of Physics, Missouri University of Science and Technology.

  15. Absolute Charge Exchange Cross Sections for ^3He^2+ Collisions with ^4He and H_2

    Science.gov (United States)

    Mawhorter, R. J.; Greenwood, J.; Smith, S. J.; Chutjian, A.

    2002-05-01

    The JPL charge exchange beam-line(J.B. Greenwood, et al., Phys. Rev A 63), 062707 (2001) was modified to increase the forward acceptance angle and enable the measurement of total charge-exchange cross sections for slow, light, highly-charged ion collisions with neutral targets(R. E. Olson and M. Kimura, J. Phys. B 15), 4231 (1982). Data are presented for single charge exchange cross sections for ^3He^2+ nuclei scattered by ^4He and H2 in the energy range 0.33-4.67 keV/amu. For both targets there is good agreement with Kusakabe, et al.(T. Kusakabe, et al., J. Phys. Soc. Japan 59), 1218 (1990). Angular collection is studied by a comparison with differential measurements(D. Bordenave-Montesquieu and R. Dagnac, J. Phys. B 27), 543 (1994), as well as with earlier JPL results(J.B. Greenwood, et al., Ap. J. 533), L175 (2000), ibid. 529, 605 (2000) using heavier projectiles and targets. This work was carried out at JPL/Caltech, and was supported through contract with NASA. RJM thanks the NRC for a Senior Associateship at JPL.

  16. Reactor antineutrino detector iDREAM.

    Science.gov (United States)

    Gromov, M. B.; Lukyanchenko, G. A.; Novikova, G. J.; Obinyakov, B. A.; Oralbaev, A. Y.; Skorokhvatov, M. D.; Sukhotin, S. V.; Chepurnov, A. S.; Etenko, A. V.

    2017-09-01

    Industrial Detector for Reactor Antineutrino Monitoring (iDREAM) is a compact (≈ 3.5m 2) industrial electron antineutrino spectrometer. It is dedicated for remote monitoring of PWR reactor operational modes by neutrino method in real-time. Measurements of antineutrino flux from PWR allow to estimate a fuel mixture in active zone and to check the status of the reactor campaign for non-proliferation purposes. LAB-based gadolinium doped scintillator is exploited as a target. Multizone architecture of the detector with gamma-catcher surrounding fiducial volume and plastic muon veto above and below ensure high efficiency of IBD detection and background suppression. DAQ is based on Flash ADC with PSD discrimination algorithms while digital trigger is programmable and flexible due to FPGA. The prototype detector was started up in 2014. Preliminary works on registration Cerenkov radiation produced by cosmic muons were established with distilled water inside the detector in order to test electronic and slow control systems. Also in parallel a long-term measurements with different scintillator samples were conducted.

  17. Folding model study of the charge-exchange scattering to the isobaric analog state and implication for the nuclear symmetry energy

    Energy Technology Data Exchange (ETDEWEB)

    Khoa, Dao T.; Thang, Dang Ngoc [VINATOM, Institute for Nuclear Science and Technique, Hanoi (Viet Nam); Loc, Bui Minh [VINATOM, Institute for Nuclear Science and Technique, Hanoi (Viet Nam); University of Pedagogy, Ho Chi Minh City (Viet Nam)

    2014-02-15

    The Fermi transition (ΔL = ΔS = 0 and ΔT = 1) between the nuclear isobaric analog states (IAS), induced by the charge-exchange (p, n) or ({sup 3}He, t) reaction, can be considered as ''elastic'' scattering of proton or {sup 3}He by the isovector term of the optical potential (OP) that flips the projectile isospin. The accurately measured (p, n) or ({sup 3}He, t) scattering cross section to the IAS can be used, therefore, to probe the isospin dependence of the proton or {sup 3}He optical potential. Within the folding model, the isovector part of the OP is determined exclusively by the neutron-proton difference in the nuclear densities and the isospin dependence of the effective nucleon-nucleon (NN) interaction. Because the isovector coupling explicitly links the isovector part of the proton or {sup 3}He optical potential to the cross section of the charge-exchange (p, n) or ({sup 3}He, t) scattering to the IAS, the isospin dependence of the effective (in-medium) NN interaction can be well tested in the folding model analysis of these charge-exchange reactions. On the other hand, the same isospin- and density-dependent NN interaction can also be used in a Hartree-Fock calculation of asymmetric nuclear matter, to estimate the nuclear matter energy and its asymmetry part (the nuclear symmetry energy). As a result, the fine-tuning of the isospin dependence of the effective NN interaction against the measured (p, n) or ({sup 3}He, t) cross sections should allow us to make some realistic prediction of the nuclear symmetry energy and its density dependence. (orig.)

  18. Folding model study of the charge-exchange scattering to the isobaric analog state and implication for the nuclear symmetry energy

    International Nuclear Information System (INIS)

    Khoa, Dao T.; Thang, Dang Ngoc; Loc, Bui Minh

    2014-01-01

    The Fermi transition (ΔL = ΔS = 0 and ΔT = 1) between the nuclear isobaric analog states (IAS), induced by the charge-exchange (p, n) or ( 3 He, t) reaction, can be considered as ''elastic'' scattering of proton or 3 He by the isovector term of the optical potential (OP) that flips the projectile isospin. The accurately measured (p, n) or ( 3 He, t) scattering cross section to the IAS can be used, therefore, to probe the isospin dependence of the proton or 3 He optical potential. Within the folding model, the isovector part of the OP is determined exclusively by the neutron-proton difference in the nuclear densities and the isospin dependence of the effective nucleon-nucleon (NN) interaction. Because the isovector coupling explicitly links the isovector part of the proton or 3 He optical potential to the cross section of the charge-exchange (p, n) or ( 3 He, t) scattering to the IAS, the isospin dependence of the effective (in-medium) NN interaction can be well tested in the folding model analysis of these charge-exchange reactions. On the other hand, the same isospin- and density-dependent NN interaction can also be used in a Hartree-Fock calculation of asymmetric nuclear matter, to estimate the nuclear matter energy and its asymmetry part (the nuclear symmetry energy). As a result, the fine-tuning of the isospin dependence of the effective NN interaction against the measured (p, n) or ( 3 He, t) cross sections should allow us to make some realistic prediction of the nuclear symmetry energy and its density dependence. (orig.)

  19. Observed Limits on Charge Exchange Contributions to the Diffuse X-Ray Background

    Science.gov (United States)

    Crowder, S. G.; Barger, K. A.; Brandl, D. E.; Eckart, M. E.; Galeazzi, M.; Kelley, R. L.; Kilbourne, C. A.; McCammon, D.; Pfendner, C. G.; Porter, F. S.; hide

    2012-01-01

    We present a high-resolution spectrum of the diffuse X-ray background from 0.1 to 1 keV for an approximately 1 sr region of the sky centered at l = 90 degrees b = +60 degrees using a 36 pixel array of microcalorimeters flown on a sounding rocket. With an energy resolution of 11 eV FWHM below 1 keV, the spectrum s observed line ratios help separate charge exchange contributions originating within the heliosphere from thermal emission of hot gas in the interstellar medium. The X-ray sensitivity below 1 keV was reduced by about a factor of four from contamination that occurred early in the flight, limiting the significance of the results. The observed centroid of helium-like O VII is 568 (sup +2 (sub -3) eV at 90% confidence. Since the centroid expected for thermal emission is 568.4 eV and for charge exchange is 564.2 eV, thermal emission appears to dominate for this line complex. The dominance of thermal emission is consistent with much of the high-latitude O VII emission originating in 2-3 x 10(exp 6) K gas in the Galactic halo. On the other hand, the observed ratio of C VI Lygamma to Lyalpha is 0.3 plus or minus 0.2. The expected ratios are 0.04 for thermal emission and 0.24 for charge exchange, indicating that charge exchange must contribute strongly to this line and therefore potentially to the rest of the ROSAT R12 band usually associated with 10(sup 6) K emission from the Local Hot Bubble. The limited statistics of this experiment and systematic uncertainties due to the contamination require only greater than 32% thermal emission for O VII and greater than 20% from charge exchange for C VI at the 90% confidence level. An experimental gold coating on the silicon substrate of the array greatly reduced extraneous signals induced on nearby pixels from cosmic rays passing through the substrate, reducing the triggered event rate by a factor of 15 from a previous flight of the instrument.

  20. (p,n) and (n,p) reactions as probes of isovector giant monopole resonances

    International Nuclear Information System (INIS)

    Auerbach, N.; Bowman, J.D.; Franey, M.A.; Love, W.G.

    1983-01-01

    Nucleon charge exchange reactions are explored as prospective probes of isovector giant monopole resonances. Using charge exchange transition densities based on random-phase approximation sum rules, distorted wave impulse approximation calculations are made for the (p,n) and (n,p) reactions exciting the isovector giant monopole resonances in several nuclei at bombarding energies of 120 and 800 MeV. Based on our calculations, the charge exchange reactions at 800 MeV appear more promising

  1. Development of the reactor antineutrino detection technology within the iDream project

    Science.gov (United States)

    Gromov, M.; Kuznetsov, D.; Murchenko, A.; Novikova, G.; Obinyakov, B.; Oralbaev, A.; Plakitina, K.; Skorokhvatov, M.; Sukhotin, S.; Chepurnov, A.; Etenko, A.

    2017-12-01

    The iDREAM (industrial Detector for reactor antineutrino monitoring) project is aimed at remote monitoring of the operating modes of the atomic reactor on nuclear power plant to ensure a technical support of IAEA non-proliferation safeguards. The detector is a scintillator spectrometer. The sensitive volume (target) is filled with a liquid organic scintillator based on linear alkylbenzene where reactor antineutrinos will be detected via inverse beta-decay reaction. We present first results of laboratory tests after physical launch. The detector was deployed at sea level without background shielding. The number of calibrations with radioactive sources was conducted. All data were obtained by means of a slow control system which was put into operation.

  2. Spatially resolved charge exchange flux calculations on the Toroidal Pumped Limiter of Tore Supra

    International Nuclear Information System (INIS)

    Marandet, Y.; Tsitrone, E.; Boerner, P.; Reiter, D.; Beaute, A.; Delchambre, E.; Escarguel, A.; Brezinsek, S.; Genesio, P.; Gunn, J.; Monier-Garbet, P.; Mitteau, R.; Pegourie, B.

    2009-01-01

    A spatially resolved calculation of the charge exchange particle and energy fluxes on the Toroidal Pumped Limiter (TPL) of Tore Supra is presented, as a first step towards a better understanding and modelling of carbon erosion, migration, as well as deuterium codeposition and bulk diffusion of deuterium in Tore Supra. The results are obtained with the EIRENE code run in a 3D geometry. Physical and chemical erosion maps on the TPL are calculated, and the contribution of neutrals to erosion, especially in the self-shadowed area, is calculated.

  3. Production of Polarized Ions with Nearly Resonant Charge-Exchange Collisions in Plasma

    Science.gov (United States)

    Belov, A. S.

    2008-02-01

    Review of results of development of polarized ion sources with nearly resonant charge-exchange plasma ionizer is presented. Pulsed beams of polarized protons with peak intensity up to 11 mA and polarization of 80% and polarized negative hydrogen ions with peak current of 4 mA and polarization of 91% have been obtained. Polarized deuterons, negative deuterium ions and 3He++ ions can be produced by this method as well. A study of a pulsed polarized atomic hydrogen beam has been performed. It was found that intensity of the pulsed atomic hydrogen beam is limited by a beam-skimmer interference and by noncomplete cooling of hydrogen atoms.

  4. Production of Polarized Ions with Nearly Resonant Charge-Exchange Collisions in Plasma

    International Nuclear Information System (INIS)

    Belov, A. S.

    2008-01-01

    Review of results of development of polarized ion sources with nearly resonant charge-exchange plasma ionizer is presented. Pulsed beams of polarized protons with peak intensity up to 11 mA and polarization of 80% and polarized negative hydrogen ions with peak current of 4 mA and polarization of 91% have been obtained. Polarized deuterons, negative deuterium ions and 3 He ++ ions can be produced by this method as well. A study of a pulsed polarized atomic hydrogen beam has been performed. It was found that intensity of the pulsed atomic hydrogen beam is limited by a beam-skimmer interference and by noncomplete cooling of hydrogen atoms

  5. High energy charge exchange np and antipp scattering using the dual fermion model

    International Nuclear Information System (INIS)

    Weigt, G.

    1976-01-01

    The five independent helicity amplitudes Phisub(i)(s, t) calculated by Mandelstam from the Neveu-Schwarz-Ramond model for fermion-antifermion scattering are used in the Regge limit for a phenomenological description of high energy np and antipp charge exchange scattering. A forward spike which widens with increasing energy as well as an energy dependence changing from lower to higher energy data are reproduced by these non-evasive dual Born amplitudes using π, A 2 and rho Regge pole t-channel exchanges. (author)

  6. Oxygen ionization rates at Mars and Venus - Relative contributions of impact ionization and charge exchange

    Science.gov (United States)

    Zhang, M. H. G.; Luhmann, J. G.; Nagy, A. F.; Spreiter, J. R.; Stahara, S. S.

    1993-01-01

    Oxygen ion production rates above the ionopauses of Venus and Mars are calculated for photoionization, charge exchange, and solar wind electron impact ionization processes. The latter two require the use of the Spreiter and Stahara (1980) gas dynamic model to estimate magnetosheath velocities, densities, and temperatures. The results indicate that impact ionization is the dominant mechanism for the production of O(+) ions at both Venus and Mars. This finding might explain both the high ion escape rates measured by Phobos 2 and the greater mass loading rate inferred for Venus from the bow shock positions.

  7. Cross sections of electron excitation out of metastable helium levels with a fast metastable target product produced via charge exchange

    International Nuclear Information System (INIS)

    Lagus, M.E.; Boffard, J.B.; Anderson, L.W.; Lin, C.C.

    1996-01-01

    Absolute direct cross sections for electron excitation out of the 2 3 S level and into the 3 3 D, 4 3 D, and 3 3 S levels of the helium atom from threshold to 500 eV and into the 3 3 P level over a more limited energy range have been measured using a fast metastable atomic beam target. We produce the metastable atoms via near-resonant charge exchange between a 1.6-keV He + ion beam and Cs vapor. Because this reaction is highly nonresonant with the ground state of helium, the charge-transfer process yields a primarily metastable beam. We use a thermal detector which we calibrate with ions to measure absolutely the neutral beam flux. The atomic beam is crossed by an electron beam, and we collect the resulting fluorescence at right angles to both the electron and atomic beams. We obtain the cross sections for excitation out of the 2 3 S level into the various excited levels by monitoring the emission out of the excited level of interest. copyright 1996 The American Physical Society

  8. Reactor Monitoring with Antineutrinos - A Progress Report

    Science.gov (United States)

    Bernstein, Adam

    2012-08-01

    The Reactor Safeguards regime is the name given to a set of protocols and technologies used to monitor the consumption and production of fissile materials in nuclear reactors. The Safeguards regime is administered by the International Atomic Energy Agency (IAEA), and is an essential component of the global Treaty on Nuclear Nonproliferation, recently renewed by its 189 remaining signators. (The 190th, North Korea, withdrew from the Treaty in 2003). Beginning in Russia in the 1980s, a number of researchers worldwide have experimentally demonstrated the potential of cubic meter scale antineutrino detectors for non-intrusive real-time monitoring of fissile inventories and power output of reactors. The detectors built so far have operated tens of meters from a reactor core, outside of the containment dome, largely unattended and with remote data acquisition for an entire 1.5 year reactor cycle, and have achieved levels of sensitivity to fissile content of potential interest for the IAEA safeguards regime. In this article, I will describe the unique advantages of antineutrino detectors for cooperative monitoring, consider the prospects and benefits of increasing the range of detectability for small reactors, and provide a partial survey of ongoing global research aimed at improving near-field and far field monitoring and discovery of nuclear reactors.

  9. Long Distance Reactor Antineutrino Flux Monitoring

    Science.gov (United States)

    Dazeley, Steven; Bergevin, Marc; Bernstein, Adam

    2015-10-01

    The feasibility of antineutrino detection as an unambiguous and unshieldable way to detect the presence of distant nuclear reactors has been studied. While KamLAND provided a proof of concept for long distance antineutrino detection, the feasibility of detecting single reactors at distances greater than 100 km has not yet been established. Even larger detectors than KamLAND would be required for such a project. Considerations such as light attenuation, environmental impact and cost, which favor water as a detection medium, become more important as detectors get larger. We have studied both the sensitivity of water based detection media as a monitoring tool, and the scientific impact such detectors might provide. A next generation water based detector may be able to contribute to important questions in neutrino physics, such as supernova neutrinos, sterile neutrino oscillations, and non standard electroweak interactions (using a nearby compact accelerator source), while also providing a highly sensitive, and inherently unshieldable reactor monitoring tool to the non proliferation community. In this talk I will present the predicted performance of an experimental non proliferation and high-energy physics program. Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344. Release number LLNL-ABS-674192.

  10. High spatial and temporal resolution charge exchange recombination spectroscopy on the HL-2A tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Y. L.; Yu, D. L., E-mail: yudl@swip.ac.cn; Liu, L.; Cao, J. Y.; Sun, A. P.; Ma, Q.; Chen, W. J.; Liu, Yi; Yan, L. W.; Yang, Q. W.; Duan, X. R.; Liu, Yong [Southwestern Institute of Physics, Chengdu 610041 (China); Ida, K. [National Institute for Fusion Science, Toki 509-5292 (Japan); Hellermann, M. von [ITER Diagnostic Team, IO, Route de Vinon sur Verdon, 13115 St Paul lez Durance (France); FOM-Institute for Plasma physics “Rijnhuizen,” Association EURATOM, Trilateral Euregio Cluster, 3430 BE Nieuwegein (Netherlands)

    2014-10-01

    A 32/64-channel charge exchange recombination spectroscopy (CXRS) diagnostic system is developed on the HL-2A tokamak (R = 1.65 m, a = 0.4 m), monitoring plasma ion temperature and toroidal rotation velocity simultaneously. A high throughput spectrometer (F/2.8) and a pitch-controlled fiber bundle enable the temporal resolution of the system up to 400 Hz. The observation geometry and an optimized optic system enable the highest radial resolution up to ~1 cm at the plasma edge. The CXRS system monitors the carbon line emission (C VI, n = 8–7, 529.06 nm) whose Doppler broadening and Doppler shift provide ion temperature and plasma rotation velocity during the neutral beam injection. The composite CX spectral data are analyzed by the atomic data and analysis structure charge exchange spectroscopy fitting (ADAS CXSFIT) code. First experimental results are shown for the case of HL-2A plasmas with sawtooth oscillations, electron cyclotron resonance heating, and edge transport barrier during the high-confinement mode (H-mode)

  11. Development of two-grating spectrometer for the charge exchange spectroscopy system on KSTAR.

    Science.gov (United States)

    Lee, Hyungho; Song, Eun-ji; Park, Young-dong; Oh, Soo-ghee; Ko, Won-Ha

    2011-06-01

    The charge exchange spectroscopy (CES) system on Korea Superconducting Tokamak Advanced Research (KSTAR) was installed last year and had been applied to measure the C VI ion temperature and rotation velocity profiles. The ion temperature and rotation velocity profiles had been estimated from the C VI 5290.5 Å (n = 8-7) charge-exchange spectrum signal measured by a Czerny-Turner type spectrometer and a thinned back-illuminated charge coupled device (CCD) camera. However, the Czerny-Turner type spectrometer used for the KSTAR CES system showed so low signal to noise ratio for KSTAR plasmas in the 2010 experimental campaign that the time resolution of the CES system had been limited to 100 ms due to the increased exposure time of the attached CCD camera. Then, new two-grating spectrometer had been developed in order to improve the time resolution of the CES system. The spectrometer consists of two gratings (1200 g/mm and 1800 g/mm each) with additive configuration, concave mirrors (f = 50 cm), and a cylindrical lens (f = 50 cm). The time resolution of the CES system increases by a factor of 2-4 with the two-grating spectrometer. The C VI ion temperature and rotation velocity profiles obtained by the two-grating spectrometer are compared to those by Czerny-Turner type spectrometer in this paper. © 2011 American Institute of Physics

  12. Determining reactor fuel type from continuous antineutrino monitoring

    OpenAIRE

    Jaffke, Patrick; Huber, Patrick

    2016-01-01

    We investigate the ability of an antineutrino detector to determine the fuel type of a reactor. A hypothetical 5t antineutrino detector is placed 25m from the core and measures the spectral shape and rate of antineutrinos emitted by fission fragments in the core for a number of 90 day periods. Our results indicate that four major fuel types can be differentiated from the variation of fission fractions over the irradiation time with a true positive probability of detection at 95%. In addition,...

  13. Heavy quark production by neutrinos and antineutrinos

    International Nuclear Information System (INIS)

    Scott, D.M.; Tanaka, K.

    1979-01-01

    The rate for producing t- and b-quarks in, respectively, neutrino and antineutrino interactions with nucleons are estimated. Experimental quark parton distribution functions, SU(2) x SU(2) x U(1) gauge group mixing angles, and threshold suppression through rescaling are used in the calculation. The ratios to total cross sections of b-quark production by anti nu, R/sub b//sup anti nu/, and t-quark production by ν, R/sub t//sup nu/, are, respectively, R/sub b//sup anti nu/ approximately equal to 10 -4 and R/sub t//sup nu/ approximately equal to 10 -5 for an incident energy of 200 GeV. 13 references

  14. The reactor antineutrino anomaly and low energy threshold neutrino experiments

    Science.gov (United States)

    Cañas, B. C.; Garcés, E. A.; Miranda, O. G.; Parada, A.

    2018-01-01

    Short distance reactor antineutrino experiments measure an antineutrino spectrum a few percent lower than expected from theoretical predictions. In this work we study the potential of low energy threshold reactor experiments in the context of a light sterile neutrino signal. We discuss the perspectives of the recently detected coherent elastic neutrino-nucleus scattering in future reactor antineutrino experiments. We find that the expectations to improve the current constraints on the mixing with sterile neutrinos are promising. We also analyze the measurements of antineutrino scattering off electrons from short distance reactor experiments. In this case, the statistics is not competitive with inverse beta decay experiments, although future experiments might play a role when compare it with the Gallium anomaly.

  15. Ray tracing analysis of stray light for charge exchange recombination spectroscopy on ITER

    International Nuclear Information System (INIS)

    Kajita, Shin; De Bock, Maarten; Von Hellermann, Manfred; Kukushkin, Andrei; Barnsley, Robin

    2015-01-01

    Charge exchange recombination spectroscopy (CXRS) provides basic measurements in ITER such as the ion temperature, plasma rotation, and the impurity and helium content. One of the issues concerning all spectroscopic measurements in ITER is the influence of the reflection of light in a vacuum vessel, since ITER will have a full metallic wall, which has higher optical reflectance than a carbon wall. The noise level can be enhanced and the signal can be disturbed by the reflection. In this study, the influences of the light reflection on the CXRS measurement have been investigated using a ray tracing simulation. Influences of the reflection of the active CXRS signal, the light emission from the divertor and scrape off layer, and bremsstrahlung are quantitatively shown in typical discharge scenario cases. (paper)

  16. Effect of injection energy on residual dose around the charge exchange foil

    Directory of Open Access Journals (Sweden)

    Kazami Yamamoto

    2012-12-01

    Full Text Available The rapid cycling synchrotron (RCS of Japan Proton Accelerator Research Complex (J-PARC and the accumulator ring (AR of Spallation Neutron Source (SNS can be used as high-power pulsed neutron sources. In both cases, the injection region becomes one of the highest activation areas in the ring. However, residual dose distributions have revealed that the highest activation points in the J-PARC RCS and the SNS AR are different in detail. The dose of the charge exchange chamber in the SNS is more than 100 times larger than that of the RCS though the ratio of beam power is less than 10. We investigated the reason of this difference by Geant4 and MARS, and the calculation results indicated that the difference was due to the dependence of the neutron and pion production rate on the injection energy.

  17. A study of charge-exchange neutrals from a rotating plasma

    International Nuclear Information System (INIS)

    Jorgensen, L.W.; Sillesen, A.H.

    1980-01-01

    Measurements of charge-exchange neutrals leaving a rotating plasma (a puffatron device) are reported. Neutrals are observed only during the breakdown phase (2-3 μs) indicating that the created plasma is fully ionized. Several energy spectra of the neutrals for different plasma parameters are obtained. These spectra are grossly explained using a single-particle orbit model of the plasma ions. Assuming a Maxwellian distribution for the spread in the ion Larmor energy for the central part of the measured energy spectra, it is possible to determine the ion energy during the breakdown phase. Neutral particle measurements at different distances from the puffatron midplane show ionization velocities parallel with the magnetic field of about 2 . 10 4 ms -1 and plasma expansion velocities of about 5-6 . 10 4 ms -1 corresponding to an electron temperature of about 25 eV. (author)

  18. Charge exchange as a recombination mechanism in high-temperature plasmas

    International Nuclear Information System (INIS)

    Hulse, R.A.; Post, D.E.; Mikkelsen, D.R.

    1980-03-01

    Charge exchange with neutral hydrogen is examined as a recombination mechanism for multi-charged impurity ions present in high-temperature fusion plasmas. At sufficiently low electron densities, fluxes of atomic hydrogen produced by either the injection of neutral heating beams or the background of thermal neutrals can yield an important or even dominant recombination process for such ions. Equilibrium results are given for selected impurity elements showing the altered ionization balance and radiative cooling rate produced by the presence of various neutral populations. A notable result is that the stripping of impurities to relatively non-radiative ionization states with increasing electron temperature can be postponed or entirely prevented by the application of intense neutral beam heating power. A time dependent calculation modelling the behavior of iron in recent PLT tokamak high power neutral beam heating experiments is also presented

  19. Theoretical study of charge exchange, ionization and electron loss processes, relevant to controlled thermonuclear research

    International Nuclear Information System (INIS)

    Janev, R.

    1981-03-01

    The following processes have been studied: a) Single and double charge exchange in low, medium and high energy collisions of atoms with multiply charged ions; b) Excitation and ionization processes in low, medium and high energy collisions between multiply charged ions and atoms; c) Ion-ion recombination and ion-pair formation collision processes between hydrogen and alkali atoms (ions); d) Resonant and Auger processes in slow collisions of atomic particles with solid surfaces (including surfaces covered by a sub-monoatomic layer). Processes a) and b) are important for the ''impurity problem'' of magnetically confined tokamak plasmas, whereas processes c) and d) for the production and transport of intense neutral beams for plasma heating

  20. Elimination of ion losses in the EhGP-10-1 charge-exchange accelerator

    International Nuclear Information System (INIS)

    Fridrikh, M.

    1986-01-01

    To improve the ion transit factor in the EhGP-10-1 charge-exchange accelerator the injector ion-optical properties are studied. The injector operates at constant high voltage U a -23 kV. Using an immersion lens the negative ion energy before entering the accelerating tube is increased up to energy proportional to the conductor voltage. A single electrostatic lens provides a cross-over in the vicinity of immersion lens. By reducing the electric field gradient at the accelerating tube inlet, optimizing input electrode voltage and shifting the single lens by 0.26 m towards the accelerating tube inlet almost full beam transit is attained at all conductor voltages

  1. Molecular (Feshbach) treatment of charge exchange Li/sup 3 +/+He collisions. I. Energies and couplings

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Riera, A.; Yanez, M.

    1986-05-15

    We point out a fundamental difference between the molecular treatment of charge exchange X/sup n/++H(1s) and X/sup n/++He(1s/sup 2/) collisions, which is that the latter process involves molecular states that are formally autoionizing. Then standard ab initio methods do not, in general, yield the relevant wave functions that are needed in the collision treatment, irrespective of whether quasimolecular autoionization be significant or not during the collision. We implement a particularly simple and useful form of the Feshbach formalism to calculate the energies of those two electron systems, and a method to evaluate the corresponding dynamical couplings is presented for the first time. Our implementation of this formalism together with the new computational techniques involved are presented in detail.

  2. Antineutrino monitoring for the Iranian heavy water reactor

    OpenAIRE

    Christensen, Eric; Huber, Patrick; Jaffke, Patrick; Shea, Thomas

    2014-01-01

    In this note we discuss the potential application of antineutrino monitoring to the Iranian heavy water reactor at Arak, the IR-40, as a non-proliferation measure. We demonstrate that an above ground detector positioned right outside the IR-40 reactor building could meet and in some cases significantly exceed the verification goals identified by IAEA for plutonium production or diversion from declared inventories. In addition to monitoring the reactor during operation, observing antineutrino ...

  3. Development of PROSPECT detectors for precision antineutrino studies

    OpenAIRE

    Norcini, Danielle; collaboration, for the PROSPECT

    2015-01-01

    PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, will use two segmented detectors positioned 7-20 m from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory to measure the U-235 antineutrino spectrum and perform a search for short-baseline oscillations as a signature of eV-scale sterile neutrinos. PROSPECT has developed Li-6 loaded liquid scintillator detectors for efficient identification of reactor antineutrinos and has measured reactor and cosmogenic b...

  4. The charge-exchange induced coupling between plasma-gas counterflows in the heliosheath

    Directory of Open Access Journals (Sweden)

    H. J. Fahr

    Full Text Available Many hydrodynamic models have been presented which give similar views of the interaction of the solar wind plasma bubble with the counterstreaming partially ionized interstellar medium. In the more recent of these models it is taken into account that the solar and interstellar hydrodynamic flows of neutral atoms and protons are coupled by mass-, momentum-, and energy-exchange terms due to charge exchange processes. We shall reinvestigate the theoretical basis of this coupling here by use of a simplified description of the heliospheric interface and describe the main physics of the H-atom penetration through the more or less standing well-known plasma wall ahead of the heliopause. Thereby we can show that the type of charge exchange coupling terms used in up-to-now hydrodynamic treatments unavoidably leads to an O-type critical point at the sonic point of the H-atom flow, thus not allowing for a continuation of the integration of the hydrodynamic set of differential equations. The remedy for this problem is given by a more accurate formulation of the momentum exchange term for quasi-and sub-sonic H-atom flows. With a refined momentum exchange term derived from basic kinetic Boltzmann principles, we instead arrive at a characteristic equation with an X-type critical point, allowing for a continuous solution from supersonic to subsonic flow conditions. This necessitates that the often treated problem of the propagation of inter-stellar H-atoms through the heliosheath has to be solved using these newly derived, differently effective plasma – gas friction forces. Substantially different results are to be expected from this context for the filtration efficiency of the heliospheric interface.

    Key words. Interplanetary physics (heliopause and solar wind termination; interstellar gas – Ionosphere (plasma temperature and density

  5. The charge-exchange induced coupling between plasma-gas counterflows in the heliosheath

    Directory of Open Access Journals (Sweden)

    H. J. Fahr

    2003-06-01

    Full Text Available Many hydrodynamic models have been presented which give similar views of the interaction of the solar wind plasma bubble with the counterstreaming partially ionized interstellar medium. In the more recent of these models it is taken into account that the solar and interstellar hydrodynamic flows of neutral atoms and protons are coupled by mass-, momentum-, and energy-exchange terms due to charge exchange processes. We shall reinvestigate the theoretical basis of this coupling here by use of a simplified description of the heliospheric interface and describe the main physics of the H-atom penetration through the more or less standing well-known plasma wall ahead of the heliopause. Thereby we can show that the type of charge exchange coupling terms used in up-to-now hydrodynamic treatments unavoidably leads to an O-type critical point at the sonic point of the H-atom flow, thus not allowing for a continuation of the integration of the hydrodynamic set of differential equations. The remedy for this problem is given by a more accurate formulation of the momentum exchange term for quasi-and sub-sonic H-atom flows. With a refined momentum exchange term derived from basic kinetic Boltzmann principles, we instead arrive at a characteristic equation with an X-type critical point, allowing for a continuous solution from supersonic to subsonic flow conditions. This necessitates that the often treated problem of the propagation of inter-stellar H-atoms through the heliosheath has to be solved using these newly derived, differently effective plasma – gas friction forces. Substantially different results are to be expected from this context for the filtration efficiency of the heliospheric interface.Key words. Interplanetary physics (heliopause and solar wind termination; interstellar gas – Ionosphere (plasma temperature and density

  6. Antineutrino monitoring of burning mixed oxide plutonium fuels

    Science.gov (United States)

    Hayes, A. C.; Trellue, H. R.; Nieto, Michael Martin; Wilson, W. B.

    2012-02-01

    Background: Antineutrino monitoring of reactors is an enhanced nuclear safeguard that is being explored by several international groups. A key question is whether such a scheme could be used to verify the destruction of plutonium loaded in a reactor as mixed oxide (MOX) fuel.Purpose: To explore the effectiveness of antineutrino monitoring for the purposes of nuclear accountability and safeguarding of MOX plutonium, we examine the magnitude and temporal variation in the antineutrino signals expected for different loadings of MOX fuels.Methods: Reactor burn simulations are carried out for four different MOX fuel loadings and the antineutrino signals as a function of fuel burnup are computed and compared.Results: The antineutrino signals from reactor-grade and weapons-grade MOX are shown to be distinct from those from burning low enriched uranium, and this signal difference increases as the MOX plutonium fraction of the reactor core increases.Conclusion: Antineutrino monitoring could be used to verify the destruction of plutonium in reactors, although verifying the grade of the plutonium being burned is found to be more challenging.

  7. CORRIGENDUM: Kinetics of highly excited states in Ar17+ charge exchange recombination fusion plasma spectroscopy Kinetics of highly excited states in Ar17+ charge exchange recombination fusion plasma spectroscopy

    Science.gov (United States)

    Marchuk, O.; Ralchenko, Yu; Janev, R. K.; Bertschinger, G.; Biel, W.

    2009-09-01

    The equation on page 6 for the rate coefficient of charge exchange contains a misprint in the integration limits, which should range from 0 to ∞. It should be replaced by the version in the associated PDF file. This error does not affect any results in the paper as the calculations were performed with the correct limits.

  8. Overview on R&D and design activities for the ITER core charge exchange spectroscopy diagnostic system

    NARCIS (Netherlands)

    Biel, W.; Baross, T.; Bourauel, P.; Dunai, D.; Durkut, M.; Erdei, G.; Hawkes, N.; Hellermann, M. von; Hogenbirk, A.; Jaspers, R.; Kiss, G.; Klinkhamer, J.F.F.; Koning, J.F.; Kotov, V.; Krasikov, Y.; Krimmer, A.; Lischtschenko, O.; Litnovsky, A.; Marchuk, O.; Neubauer, O.; Offermanns, G.; Panin, A.; Patel, K.; Pokol, G.; Schrader, M.; Snijders, B.; Szabo, V.; Valk, N.J.C. van der; Voinchet, R.; Wolters, J.; Zoletnik, S.

    2011-01-01

    The ITER core charge exchange recombination spectroscopy (core CXRS) diagnostic system is designed to provide experimental access to various measurement quantities in the ITER core plasma such as ion densities, temperatures and velocities. The implementation of the approved CXRS diagnostic principle

  9. 1st IAEA research co-ordination meeting on charge exchange cross section data for fusion plasma studies. Summary report

    International Nuclear Information System (INIS)

    Janev, R.K.

    1999-02-01

    A brief description of the proceedings and the conclusions of the 1st Research Coordination Meeting on 'Charge Exchange Cross Section Data for Fusion Plasma Studies', held on September 24-25, 1999, at the IAEA Headquarters in Vienna, Austria, is provided. The conclusions of the Meeting regarding the data collection, assessment and generation priorities are also included in the report. (author)

  10. Study of multi-electron ionization and charge exchange in HIBF

    Science.gov (United States)

    Wu, Linchun

    Beam ion stripping on background gases or plasma in a Heavy Ion Beam Fusion (HIBF) chamber increases the charge state of the beam and the diameter of the focus, complicating the final focusing on the focusing target. To model beam transport in the chamber, it is necessary to know the beam charge-state evolution, including both ionization and charge exchange dynamics. The main objective of this research is to explore theoretical approaches including scaling law. Improved models are developed to calculate multi-electron loss, especially ion stripping and charge exchange cross sections, for both near-term experiments and future power plant scale HIBF research. First, a new space-charge neutralization approach that uses electron injection is proposed for the ion beam transport in HIBF chamber. An analytical study was performed to illustrate the plasma dynamics and final neutralization effects with this technique. The results examine the effect of different injected electron profiles. Next, to improve the accuracy of such simulations, methods to improve cross sections of ionization and charge exchange are studied. Both classical and quantum mechanical approaches are examined. Attention is focused on the interaction by low-charge-state heavy ions. Multi-electron processes for dressed ions, including screening and anti-screening effects, internuclear forces, are given special attention, This analysis is complex and requires a combining several different theoretical approaches. Finally, a Classic Trajectory Monte Carlo (CTMC) model based on an improvement of Olson's n-body CTMC method is presented. This model solves the n-body ion-atom ionization problem in a regime of intent to HIBF. In the paper, a new and complete computational module for these interactions has been developed. The cross section data for Xe, Cs, and Bi ions colliding with various background gases (Xe, N2, Ar and Flibe) is presented. After the calculation of the cross section data, the predicted energy

  11. Excitation of the Δ(1232) isobar in deuteron charge exchange on hydrogen at 1.6, 1.8, and 2.3 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Mchedlishvili, D. [High Energy Physics Institute, Tbilisi State University, GE-0186 Tbilisi, Georgia (United States); Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Barsov, S. [High Energy Physics Department, Petersburg Nuclear Physics Institute, RU-188350 Gatchina (Russian Federation); Carbonell, J. [Institut de Physique Nucléaire, Université Paris-Sud, IN2P3-CNRS, F-91406 Orsay Cedex (France); Chiladze, D. [High Energy Physics Institute, Tbilisi State University, GE-0186 Tbilisi, Georgia (United States); Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Dymov, S. [Laboratory of Nuclear Problems, JINR, RU-141980 Dubna (Russian Federation); Physikalisches Institut II, Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Dzyuba, A. [High Energy Physics Department, Petersburg Nuclear Physics Institute, RU-188350 Gatchina (Russian Federation); Engels, R.; Gebel, R. [Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Glagolev, V. [Laboratory of High Energies, JINR, RU-141980 Dubna (Russian Federation); and others

    2013-10-07

    The charge-exchange break-up of polarised deuterons d{sup →}p→{pp}{sub s}n, where the final {pp}{sub s} diproton system has a very low excitation energy and hence is mainly in the {sup 1}S{sub 0} state, is a powerful tool to probe the spin-flip terms in the proton–neutron charge-exchange scattering. Recent measurements with the ANKE spectrometer at the COSY storage ring at 1.6, 1.8, and 2.27 GeV have extended these studies into the pion-production regime in order to investigate the mechanism for the excitation of the Δ(1232) isobar in the d{sup →}p→{pp}{sub s}X reaction. Values of the differential cross section and two deuteron tensor analysing powers, A{sub xx} and A{sub yy}, have been extracted as functions of the momentum transfer to the diproton or the invariant mass M{sub X} of the unobserved system X. The unpolarised cross section in the high M{sub X} region is well described in a model that includes only direct excitation of the Δ isobar through undistorted one pion exchange. However, the cross section is grossly underestimated for low M{sub X}, even when Δ excitation in the projectile deuteron is included in the calculation. Furthermore, direct Δ production through one pion exchange only reproduces the angular dependence of the difference between the two tensor analysing powers.

  12. Experimental determination of the antineutrino spectrum of the fission products of 238U

    International Nuclear Information System (INIS)

    Haag, Nils-Holger

    2013-01-01

    Fission of 238 U contributes about 10 % to the antineutrino emission of a pressurized water reactor. In the present thesis, the beta spectrum of the fission products of 238 U was determined in an experiment at the neutron source FRM II. This beta spectrum was subsequently converted into an antineutrino spectrum. This first measurement of the antineutrino spectrum supports all current and future reactor antineutrino experiments.

  13. Experimental determination of the antineutrino spectrum of the fission products of {sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Haag, Nils-Holger

    2013-10-09

    Fission of {sup 238}U contributes about 10 % to the antineutrino emission of a pressurized water reactor. In the present thesis, the beta spectrum of the fission products of {sup 238}U was determined in an experiment at the neutron source FRM II. This beta spectrum was subsequently converted into an antineutrino spectrum. This first measurement of the antineutrino spectrum supports all current and future reactor antineutrino experiments.

  14. Determining Reactor Fuel Type from Continuous Antineutrino Monitoring

    Science.gov (United States)

    Jaffke, Patrick; Huber, Patrick

    2017-09-01

    We investigate the ability of an antineutrino detector to determine the fuel type of a reactor. A hypothetical 5-ton antineutrino detector is placed 25 m from the core and measures the spectral shape and rate of antineutrinos emitted by fission fragments in the core for a number of 90-d periods. Our results indicate that four major fuel types can be differentiated from the variation of fission fractions over the irradiation time with a true positive probability of detection at approximately 95%. In addition, we demonstrate that antineutrinos can identify the burnup at which weapons-grade mixed-oxide (MOX) fuel would be reduced to reactor-grade MOX, on average, providing assurance that plutonium-disposition goals are met. We also investigate removal scenarios where plutonium is purposefully diverted from a mixture of MOX and low-enriched uranium fuel. Finally, we discuss how our analysis is impacted by a spectral distortion around 6 MeV observed in the antineutrino spectrum measured from commercial power reactors.

  15. Performance of the CERN PSB at 160 MeV with $H^{-}$ charge exchange injection

    CERN Document Server

    AUTHOR|(CDS)2084247; Santoni, Claudio

    As part of the LHC Injectors Upgrade Project, the CERN PS Booster (PSB) will be upgraded with a H- charge exchange injection system and its injection energy will be raised from 50 MeV to 160 MeV to obtain the beam brightness required for the LHC High-Luminosity Upgrade. Space charge effects like beam losses and transverse emittance blow-up at injection are expected to be the main limitations towards the achievement of the required high brightness. Studies of beam dynamics in presence of space charge in order to evaluate the performances of the PSB after the Upgrade have been performed. The first part of the work consists of measurements in the present machine, to study the effects of space charge and its interplay with resonances and to have a good set of data for code benchmarking. The code chosen for the beam tracking in presence of space charge is PTC-Orbit (and PyOrbit). Necessary numerical convergence studies are presented together with a benchmark with the PSB measurements. Once assessed the code and it...

  16. Monitoring Charge Exchange in P3HT-Nanotube Composites Using Optical and Electrical Characterisation

    Directory of Open Access Journals (Sweden)

    Lioudakis Emmanouil

    2009-01-01

    Full Text Available Abstract Charge exchange at the bulk heterojunctions of composites made by mixing single wall nanotubes (SWNTs and polymers show potential for use in optoelectronic devices such as solar cells and optical sensors. The density/total area of these heterojunctions is expected to increase with increasing SWNT concentration but the efficiency of solar cell peaks at low SWNT concentrations. Most researchers use current–voltage measurements to determine the evolution of the SWNT percolation network and optical absorption measurements to monitor the spectral response of the composites. However, these methods do not provide a detailed account of carrier transport at the concentrations of interest; i.e., near or below the percolation threshold. In this article, we show that capacitance–voltage (C–V response of (metal-(oxide-(semiconducting composite devices can be used to fill this gap in studying bulk heterojunctions. In an approach where we combine optical absorption methods withC–Vmeasurements we can acquire a unified optoelectronic response from P3HT-SWNT composites. This methodology can become an important tool for optoelectronic device optimization.

  17. Development of Fast Charge Exchange Recombination Spectroscopy by Using Interference Filter Method in JT-60U

    Science.gov (United States)

    Kobayashi, Shinji; Sakasai, Akira; Koide, Yoshihiko; Sakamoto, Yoshiteru; Kamada, Yutaka; Hatae, Takaki; Oyama, Naoyuki; Miura, Yukitoshi

    Recent developments and results of fast charge exchange recombination spectroscopy (CXRS) using interference filter method are reported. In order to measure the rapid change of the ion temperature and rotation velocity under collapse or transition phenomena with high-time resolution, two types of interference filter systems were applied to the CXRS diagnostics on the JT-60U Tokamak. One can determine the Doppler broadening and Doppler shift of the CXR emission using three interference filters having slightly different center wavelengths. A rapid estimation method of the temperature and rotation velocity without non-linear least square fitting is presented. The modification of the three-filters system enables us to improve the minimum time resolution up to 0.8 ms, which is better than that of 16.7 ms for the conventional CXRS system using the CCD detector in JT-60U. The other system having seven wavelength channels is newly fabricated to crosscheck the results obtained by the three-filters assembly, that is, to verify that the CXR emission forms a Gaussian profile under collapse phenomena. In a H-mode discharge having giant edge localized modes, the results obtained by the two systems are compared. The applicability of the three-filters system to the measurement of rapid changes in temperature and rotation velocity is demonstrated.

  18. Effect of charge exchange on ion guns and an application to inertial- electrostatic confinement devices

    International Nuclear Information System (INIS)

    Baxter, D.C.; Stuart, G.W.

    1982-01-01

    In 1967, R. L. Hirsch [J. Appl. Phys. 38, 4522 (1967)] reported neutron production rates of 10 10 neutrons per second from an electrostatic inertial confinement device. The device consisted of six ion guns injecting deuterium or a mixture of deuterium and tritium ions into an evacuated cathode chamber at 30--150 keV. No previous theoretical model for this experiment has adequately explained the observed neutron fluxes. A new model that includes the effects of charge exchange and ionization in the ion guns is analyzed. This model predicts three main features of the observed neutron flux: Neutron output proportional to gun current, neutron production localized at the center of the evacuated chamber, and neutron production decreasing with increasing neutral background gas density. Previous analysis modelled the ion guns as being monoenergetic. In this study, the ion gun output is modelled as a mixture of ions and fast neutrals with energies ranging from zero to the maximum gun energy. Using this theoretical model, a survey of the possible operating parameters indicates that the device was probably operated at or near the most efficient combined values of voltage and background pressure. Applications of the theory to other devices are discussed

  19. Proposal for making a beam of antihydrogen by two charge exchange events

    International Nuclear Information System (INIS)

    Robicheaux, F

    2010-01-01

    We have performed calculations of two successive charge transfers in a geometry that could generate a beam of antihydrogen atoms (H-bar) or reliably produce cold H-bar without having to reach extremely cold plasma temperatures. The basic idea is similar to that proposed by Hessels et al (1998 Phys. Rev. A 57 1668) except that the order of the charge transfers is reversed. A beam of highly-excited (Rydberg) Cs atoms passes through an antiproton (p-bar) plasma where a charge transfer can take place; the result is an exotic Rydberg atom (Cs + ion and a bound p-bar) which has approximately the original velocity of the Cs atom since the Cs + mass is much greater than that of the p-bar. This exotic Rydberg atom travels into a positron plasma where a second charge exchange gives antihydrogen (H-bar). The velocity distribution of the resulting H-bar is directly related to the original velocity of the Rydberg Cs atom. The binding energy of the H-bar is roughly that of the original Cs Rydberg atom; thus, the starting state of the H-bar can be controlled by choosing the initial state of the Cs atom. Because the p-barCs + binding energy can be controlled in the charge transfer, this first step, by itself, could be of interest to the exotic atom community.

  20. A fast CCD detector for charge exchange recombination spectroscopy on the DIII-D tokamak

    International Nuclear Information System (INIS)

    Thomas, D.M.; Burrell, K.H.; Groebner, R.J.; Gohil, P.

    1996-05-01

    Charge Exchange Recombination (CER) spectroscopy has become a standard diagnostic for tokamaks. CER measurements have been used to determine spatially and temporally resolved ion temperature, toroidal and poloidal ion rotation speed, impurity density and radial electric field. Knowledge of the spatial profile and temporal evolution of the electric field shear in the plasma edge is crucial to understanding the physics of the L to H transition. High speed CER measurements are also valuable for Edge Localized Mode (ELM) studies. Since the 0.52 ms minimum time resolution of our present system is barely adequate to study the time evolution of these phenomena, we have developed a new CCD detector system with about a factor of two better time resolution. In addition, our existing system detects sufficient photons to utilize the shortest time resolution only under exceptional conditions. The new CCD detector has a quantum efficiency of about 0.65, which is a factor of 7 better than our previous image intensifier-silicon photodiode detector systems. We have also equipped the new system with spectrometers of lower f/number. This combination should allow more routine operation at the minimum integration time, as well as improving data quality for measurements in the divertor-relevant region outside of the separatrix. Construction details, benchmark data and initial tokamak measurements for the new system will be presented

  1. Search for coherent muon pair production by neutrinos and antineutrinos

    International Nuclear Information System (INIS)

    Bergsma, F.; Dorenbosch, J.; Jonker, M.; Nieuwenhuis, C.; Allaby, J.V.; Amaldi, U.; Barbiellini, G.; Barone, L.; Capone, A.; Flegel, W.; Metcalf, M.; Panman, J.; Winter, K.; Aspiazu, J.; Buesser, F.W.; Daumann, H.; Gall, P.D.; Metz, E.; Niebergall, F.; Ranitzsch, K.H.; Staehelin, P.; Baroncelli, A.; Borgia, B.; Bosio, C.; Ferroni, F.; Longo, E.; Monacelli, P.; De Notaristefani, F.; Pistilli, P.; Santoni, C.; Tortora, L.; Valente, V.

    1983-01-01

    A search for coherent μ + μ - pair production has been made using the CHARM neutrino detector exposed to wide-band horn-focussed neutrino and antineutrino beams at the 400 GeV CERN SPS. Out of 3.3 x 10 6 neutrino and antineutrino induced CC events with energy greater than 10 GeV, we find two events which can be attributed to coherent production off the target nuclei (CaCO 3 ). This allows a limit to be set on the diagonal four-lepton coupling constant Gsub(d) < 1.5 Gsub(f) (90% CL). (orig.)

  2. The U238 antineutrino spectrum in the Double Chooz experiment

    Energy Technology Data Exchange (ETDEWEB)

    Haag, Nils; Oberauer, Lothar; Potzel, Walter; Schreckenbach, Klaus [Technische Universitaet, Muenchen (Germany); Lachenmaier, Tobias [Eberhard Karls Universitaet, Tuebingen (Germany)

    2011-07-01

    The DoubleChooz experiment aims at the determination of the unknown neutrino mixing parameter {Theta}{sub 13}. Two liquid scintillator detectors will measure an electron antineutrino disappearance at the Chooz site in the French ardennes. In order to improve the sensitivity, the antineutrino spectrum emitted by the Chooz reactor cores has to be determined with high accuracy. This talk focusses on the U238 spectrum, which is the only contributing spectrum, that was not measured until now. The final U238 beta spectrum is presented, and its implementation into the analysis framework is shown.

  3. Investigation of large LGB detectors for antineutrino detection

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, P. [Department of Physics, Naval Postgraduate School, Monterey, CA 93943 (United States); Bowden, N.S., E-mail: nbowden@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2011-12-21

    A detector material or configuration that can provide an unambiguous indication of neutron capture can substantially reduce random coincidence backgrounds in antineutrino detection and capture-gated neutron spectrometry applications. Here we investigate the performance of such a material, a composite of plastic scintillator and {sup 6}Li{sub 6}{sup nat}Gd({sup 10}BO{sub 3}){sub 3}:Ce (LGB) crystal shards of Almost-Equal-To 1 mm dimension and comprising 1% of the detector by mass. While it is found that the optical propagation properties of this material as currently fabricated are only marginally acceptable for antineutrino detection, its neutron capture identification ability is encouraging.

  4. Is there a high-y anomaly in antineutrino interactions

    International Nuclear Information System (INIS)

    Holder, M.; Knobloch, J.; May, J.; Paar, H.P.; Palazzi, P.; Schlatter, D.; Steinberger, J.; Suter, H.; Wahl, H.; Williams, E.G.H.; Eisele, F.; Geweniger, C.; Kleinknecht, K.; Spahn, G.; Wilutzki, H.; Dorth, W.; Dydak, F.; Hepp, V.; Tittel, K.; Wotschack, J.; Bloch, P.; Devaux, B.; Grimm, M.; Maillard, J.; Peyaud, B.; Rander, J.; Savoy-Navarro, A.; Turlay, R.; Navarria, F.L.

    1977-01-01

    We have analyzed data taken in the CERN narrow-band neutrino and antineutrino beams with regard to the ''high-y anomaly'' observed by previous experiments at Fermilab. At neutrino energies between 30 and 200 GeV, the anti ν and ν charged-current cross-section ratios and muon-inelasticity distributions disagree with the earlier results. In particular, there is no evidence for energy-dependent effects in the antineutrino data which constitute an important aspect of the alleged anomaly

  5. Partial wave analysis of the low-mass Kππ systems produced diffractively and by charge-exchange in 4.2 GeV/c K-p interactions

    International Nuclear Information System (INIS)

    Vergeest, J.S.M.

    1979-01-01

    In this thesis the author studies the (antiKππ) - system diffractively produced in the reactions K - p → K - π - π + p and K - p → anti K 0 π - π 0 p as well as the (anti Kππ) 0 system produced by charge-exchange: K - p → anti K 0 π + π - n. The data are obtained in a high statistics experiment with incident K - mesons at 4.2 GeV/c, using the CERN 2-metre hydrogen bubble chamber. (Auth.)

  6. Non-Regge and hyper-Regge effects in pion-nucleon charge exchange scattering at high energies

    International Nuclear Information System (INIS)

    Joynson, D.; Leader, E.; Nicolescu, B.; Paris-6 Univ., 75; Lopez, C.

    1975-04-01

    The experimental data on the charge exchange differential cross-section and on the difference on the π + p and π - p total cross-sections between 5GeV/c to 200GeV/c are shown to be incompatible with conventional Regge asymptotic behavior. It is shown that an additional term is required which grows in importance with energy. The precise form of the new term cannot be ascertained, but it is shown that it corresponds to a singularity at J=1 in the complex angular momentum plane. Amongst the possible types of additional term there are two which have been closely analysed: a non-Regge behavior, a hyper-Regge term which have allowed very striking predictions in particular for the charge exchange polarisation [fr

  7. Solution of the Fokker-Planck equation with mixing of angular harmonics by beam-beam charge exchange

    International Nuclear Information System (INIS)

    Mikkelsen, D.R.

    1989-09-01

    A method for solving the linear Fokker-Planck equation with anisotropic beam-beam charge exchange loss is presented. The 2-D equation is transformed to a system of coupled 1-D equations which are solved iteratively as independent equations. Although isotropic approximations to the beam-beam losses lead to inaccurate fast ion distributions, typically only a few angular harmonics are needed to include accurately the effect of the beam-beam charge exchange loss on the usual integrals of the fast ion distribution. Consequently, the algorithm converges very rapidly and is much more efficient than a 2-D finite difference method. A convenient recursion formula for the coupling coefficients is given and generalization of the method is discussed. 13 refs., 2 figs

  8. CrossRef Large numbers of cold positronium atoms created in laser-selected Rydberg states using resonant charge exchange

    CERN Document Server

    McConnell, R; Kolthammer, WS; Richerme, P; Müllers, A; Walz, J; Grzonka, D; Zielinski, M; Fitzakerley, D; George, MC; Hessels, EA; Storry, CH; Weel, M

    2016-01-01

    Lasers are used to control the production of highly excited positronium atoms (Ps*). The laser light excites Cs atoms to Rydberg states that have a large cross section for resonant charge-exchange collisions with cold trapped positrons. For each trial with 30 million trapped positrons, more than 700 000 of the created Ps* have trajectories near the axis of the apparatus, and are detected using Stark ionization. This number of Ps* is 500 times higher than realized in an earlier proof-of-principle demonstration (2004 Phys. Lett. B 597 257). A second charge exchange of these near-axis Ps* with trapped antiprotons could be used to produce cold antihydrogen, and this antihydrogen production is expected to be increased by a similar factor.

  9. SOLAR WIND CHARGE EXCHANGE EMISSION FROM THE HELIUM FOCUSING CONE: MODEL TO DATA COMPARISON

    International Nuclear Information System (INIS)

    Koutroumpa, D.; Snowden, S. L.; Collier, M. R.; Kuntz, K. D.; Lallement, R.

    2009-01-01

    A model for heliospheric solar wind charge exchange (SWCX) X-ray emission is applied to a series of XMM-Newton observations of the interplanetary focusing cone of interstellar helium. The X-ray data are from three coupled observations of the South Ecliptic Pole (SEP; to observe the cone) and the Hubble Deep Field-North (HDF-N, to monitor global variations of the SWCX emission due to variations in the solar wind (SW)) from the period 2003 November 24 to December 15. There is good qualitative agreement between the model predictions and the data, after the SEP data are corrected using the HDF-N data, with the maximum SWCX flux observed at an ecliptic longitude of ∼72 deg., consistent with the central longitude of the He cone. We observe a total excess of 2.1 ± 1.3 line unit (LU) in the O VII line and 2.0 ± 0.9 LU in the O VIII line. However, the SWCX emission model, which was adjusted for SW conditions appropriate for late 2003, predicts an excess from the He cone of only 0.5 LU and 0.2 LU, respectively, in the O VII and O VIII lines. We discuss the model to data comparison and provide possible explanations for the discrepancies. We also qualitatively re-examine our SWCX model predictions in the 1/4 keV band with data from the ROSAT All-Sky Survey toward the North Ecliptic Pole and SEP, when the He cone was probably first detected in soft X-rays.

  10. Neutron fragmentation and inclusive charge exchange in pd and π+d interactions at 195 GeV/c

    International Nuclear Information System (INIS)

    Eisenberg, Y.; Haber, B.; Hochman, D.; Koller, E.; Ronat, E.E.; Shapira, A.; Yaari, R.; Yekutieli, G.; Braun, H.; Etienne, F.; Fridman, A.; Gerber, J.P.; Jegham, E.; Juillot, P.; Maurer, G.; Voltolini, C.

    1977-01-01

    An excess of negative particles and depletion of positive particles in the backward hemisphere (c.m. system) is observed in π + and p interactions on neutron target. dsigma - /dy is compared with pp interactions and the difference is related to the slow-proton spectrum produced in the pn interactions. A neutron fragmentation component is observed, and the inclusive charge-exchange probability at the nucleon vertex is found to be about 0.4

  11. Charge exchange recombination in X-ray spectra of He-like argon measured at the tokamak TEXTOR

    Energy Technology Data Exchange (ETDEWEB)

    Schlummer, Tobias

    2014-06-16

    Charge exchange recombination between ions and atomic hydrogen is an important atomic process in magnetically confined fusion plasmas. Besides radiative cooling of the plasma edge, charge exchange causes modifications of the ionization balance and the population densities of excited ion states. The central goal of this work is to investigate the influence of charge exchange on X-ray spectra measured at the tokamak TEXTOR. A new 2D X-ray spectrometer developed for future use at the stellarator W7-X was recently installed at TEXTOR. The spectrometer is optimized for measuring the K{sub α}-spectrum of He-like argon (1s2l - 1s{sup 2}) at wavelengths close to 4 Aa. K{sub α}-spectroscopy on He-like impurity ions is an established diagnostic for electron and ion temperature measurements in fusion plasmas. Still, up to now the observed intensity ratios of the K{sub α}-lines and their associated satellites are not fully understood. They show significant deviations from the predictions made by basic corona models. In the past charge exchange with the neutral particle background and radial impurity transport have been discussed as likely explanations. Yet a detailed description of the experimental spectra still has not been achieved. To reconstruct the 2D K{sub α}-spectra measured at TEXTOR the radial argon ion distribution is modeled using an impurity transport code. The model accounts for charge exchange and transport on basis of given radial profiles of the neutral particle density n{sub 0}(r) and the diffusion coefficient D {sub perpendicular} {sub to} (r). The theoretical spectrum is then constructed based on the processes relevant for line emission. Within an iterative procedure n{sub 0}(r) and D {sub perpendicular} {sub to} (r) are varied until consistency between the theoretical and the experimental spectra is achieved. It is shown that the 2D K{sub α}-spectra allow a clear distinction of charge exchange and transport effects, ensuring unique solutions for n

  12. Analysis of the charge exchange between the human body and ground: evaluation of "earthing" from an electrical perspective.

    Science.gov (United States)

    Chamberlin, Kent; Smith, Wayne; Chirgwin, Christopher; Appasani, Seshank; Rioux, Paul

    2014-12-01

    The purpose of this study was to investigate "earthing" from an electrical perspective through measurement and analysis of the naturally occurring electron flow between the human body or a control and ground as this relates to the magnitude of the charge exchange, the relationship between the charge exchange and body functions (respiration and heart rate), and the detection of other information that might be contained in the charge exchange. Sensitive, low-noise instrumentation was designed and fabricated to measure low-level current flow at low frequencies. This instrumentation was used to record current flow between human subjects or a control and ground, and these measurements were performed approximately 40 times under varied circumstances. The results of these measurements were analyzed to determine if information was contained in the current exchange. The currents flowing between the human body and ground were small (nanoamperes), and they correlated with subject motion. There did not appear to be any information contained in this exchange except for information about subject motion. This study showed that currents flow between the environment (earth) and a grounded human body; however, these currents are small (nanoamperes) and do not appear to contain information other than information about subject motion.

  13. A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lyubushkin, V.; Bunyatov, S.; Chukanov, A.; Klimov, O.; Kustov, D.; Nefedov, Yu.; Samoylov, O.; Tereshchenko, V. [JINR, Dubna (Russian Federation); Popov, B. [JINR, Dubna (Russian Federation); LPNHE, Univ. of Paris VI and VII, Paris (France); Kim, J.J.; Godley, A.; Ling, J.; Mishra, S.R.; Petti, R.; Seaton, M.; Wu, Q. [Univ. of South Carolina, Columbia, SC (United States); Camilleri, L.; Autiero, D.; Di Lella, L.; Couto e Silva, E. do; Ferrere, D.; Grant, A.; Kokkonen, J.; Linssen, L.; Placci, A.; Stiegler, U.; Tsesmelis, E.; Vidal-Sitjes, G.; Wilson, F.F. [CERN, Geneva (Switzerland); Levy, J.M.; Astier, P.; Banner, M.; Dumarchez, J.; Lachaud, C.; Letessier-Selvon, A.; Schahmaneche, K.; Touchard, A.M.; Vannucci, F. [LPNHE, Univ. of Paris VI and VII, Paris (France); Mezzetto, M.; Baldo-Ceolin, M.; Bobisut, F.; Collazuol, G.; Contalbrigo, M.; Gibin, D.; Guglielmi, A.; Lacaprara, S.; Laveder, M.; Rebuffi, L.; Sconza, A.; Zuccon, P. [Univ. of Padova (Italy); INFN, Padova (Italy); Naumov, D. [JINR, Dubna (Russian Federation); Univ. of Florence (Italy); INFN, Florence (Italy); Alekhin, S. [Inst. for High Energy Physics, Protvino, Moscow Region (Russian Federation); Baldisseri, A.; Besson, N.; Bouchez, J.; Gosset, J.; Hagner, C.; Mechain, X.; Meyer, J.P.; Stolarczyk, T.; Zaccone, H. [DAPNIA, Saclay (France); Bassompierre, G.; Gaillard, J.M.; Gouanere, M.; Mendiburu, J.P.; Nedelec, P.; Pessard, H.; Sillou, D. [LAPP, Annecy (France); Benslama, K.; Degaudenzi, H.; Joseph, C.; Juget, F.; Nguyen-Mau, C.; Sozzi, G.; Tareb-Reyes, M.; Tran, M.T.; Vacavant, L.; Vieira, J.M. [Univ. of Lausanne, Lausanne (Switzerland); Bird, I. [CERN, Geneva (Switzerland); Univ. of Lausanne (Switzerland); Blumenfeld, B.; Long, J. [Johns Hopkins Univ., Baltimore, MD (United States); Boyd, S.; Ellis, M.; Peak, L.S.; Ulrichs, J.; Varvell, K.E.; Yabsley, B.D. [Univ. of Sydney (Australia); Bueno, A. [Harvard Univ., Cambridge, MA (United States); ETH Zurich (Switzerland)] [and others

    2009-10-15

    We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions ({nu}{sub {mu}}n {yields}{mu}{sup -}p and anti {nu}{sub {mu}}p{yields}{mu}{sup +}n) using a set of experimental data collected by the NOMAD Collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly carbon) normalizing it to the total {nu}{sub {mu}}(anti {nu}{sub {mu}}) charged-current cross section. The results for the flux-averaged QEL cross sections in the (anti)neutrino energy interval 3-100 GeV are left angle {sigma}{sub qel} right angle {sub {nu}}{sub {mu}}=(0.92{+-}0.02(stat){+-}0.06(syst)) x 10{sup -38} cm{sup 2} and left angle {sigma}{sub qel} right angle {sub anti} {sub {nu}{sub {mu}}}{sub =}(0.81{+-}0.05(stat){+-}0.09(syst)) x 10{sup -38} cm{sup 2} for neutrino and antineutrino, respectively. The axial mass parameter M{sub A} was extracted from the measured quasi-elastic neutrino cross section. The corresponding result is M{sub A}=1.05{+-}0.02(stat){+-}0.06(syst) GeV. It is consistent with the axial mass values recalculated from the antineutrino cross section and extracted from the pure Q{sup 2} shape analysis of the high purity sample of {nu}{sub {mu}} quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured M{sub A} is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of M{sub A} is lower than those recently published by K2K and MiniBooNE Collaborations. However, within the large errors quoted by these experiments on M{sub A}, these results are compatible with the more precise NOMAD value. (orig.)

  14. Measuring Antineutrino Oscillations with the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Justin John [Univ. of Oxford (United Kingdom)

    2008-09-01

    MINOS is a long baseline neutrino oscillation experiment. A manmade beam of predominantly muon neutrinos is detected both 1 km and 735 km from the production point by two functionally identical detectors. A comparison of the energy spectra measured by the two detectors shows the energy-dependent disappearance of muon neutrinos characteristic of oscillations and allows a measurement of the parameters governing the oscillations. This thesis presents work leading to measurements of disappearance in the 6% $\\bar{v}$μ background in that beam. A calibration is developed to correct for time-dependent changes in the responses of both detectors, reducing the corresponding uncertainty on hadronic energy measurements from 1.8% to 0.4% in the near detector and from 0.8% to 0.4% in the far detector. A method of selecting charged current $\\bar{v}$μ events is developed, with purities (efficiencies) of 96.5% (74.4%) at the near detector, and 98.8% (70.9%) at the far detector in the region below 10 GeV reconstructed antineutrino energy. A method of using the measured near detector neutrino energy spectrum to predict that expected at the far detector is discussed, and developed for use in the $\\bar{v}$μ analysis. Sources of systematic uncertainty contributing to the oscillation measurements are discussed. In the far detector, 32 charged current $\\bar{v}$μ events are observed below a reconstructed energy of 30 GeV, compared to an expectation of 47.8 for Δ$\\bar{m}$atm2 = Δ$\\bar{m}$atm2, sin2(2$\\bar{θ}$23) = sin2(2θ23). This deficit, in such a low-statistics sample, makes the result difficult to interpret in the context of an oscillation parameter measurement. Possible sources for the discrepancy are discussed, concluding that considerably more data are required for a definitive solution. Running MINOS with a dedicated $\\bar

  15. Prospects for improved understanding of isotopic reactor antineutrino fluxes

    Science.gov (United States)

    Gebre, Y.; Littlejohn, B. R.; Surukuchi, P. T.

    2018-01-01

    Predictions of antineutrino fluxes produced by fission isotopes in a nuclear reactor have recently received increased scrutiny due to observed differences in predicted and measured inverse beta decay (IBD) yields, referred to as the "reactor antineutrino flux anomaly." In this paper, global fits are applied to existing IBD yield measurements to produce constraints on antineutrino production by individual plutonium and uranium fission isotopes. We find that fits including measurements from highly U 235 -enriched cores and fits including Daya Bay's new fuel evolution result produce discrepant best-fit IBD yields for U 235 and Pu 239 . This discrepancy can be alleviated in a global analysis of all data sets through simultaneous fitting of Pu 239 , U 235 , and U 238 yields. The measured IBD yield of U 238 in this analysis is (7.02 ±1.65 )×10-43 cm2/fission , nearly two standard deviations below existing predictions. Future hypothetical IBD yield measurements by short-baseline reactor experiments are examined to determine their possible impact on the global understanding of isotopic IBD yields. It is found that future improved short-baseline IBD yield measurements at both high-enriched and low-enriched cores can significantly improve constraints for U 235 , U 238 , and Pu 239 , providing comparable or superior precision to existing conversion- and summation-based antineutrino flux predictions. Systematic and experimental requirements for these future measurements are also investigated.

  16. Monitoring of spent nuclear fuel with antineutrino detectors

    Science.gov (United States)

    Brdar, Vedran

    2017-09-01

    We put forward the possibility of employing antineutrino detectors in order to control the amounts of spent nuclear fuel in repositories or, alternatively, to precisely localize the underground sources of nuclear material. For instance, we discuss the applicability in determining a possible leakage of stored nuclear material which would aid in preventing environmental problems. The long-term storage facilities are also addressed.

  17. On neutrino and antineutrino scattering by electrons, and by partons

    International Nuclear Information System (INIS)

    Bell, J.S.; Dass, G.V.

    1975-09-01

    Assuming a non-derivative point interaction, and Born approximation, there are some simple relations between neutrino and antineutrino scattering on electrons or partons. They have been observed already, for some special cases, in the results of explicit calculations. Here they are obtained from simple general considerations. (author)

  18. Anti-neutrino imprint in solar neutrino flare

    Science.gov (United States)

    Fargion, D.

    2006-10-01

    A future neutrino detector at megaton mass might enlarge the neutrino telescope thresholds revealing cosmic supernova background and largest solar flares (SFs) neutrinos. Indeed the solar energetic (Ep>100 MeV) flare particles (protons, α), while scattering among themselves on solar corona atmosphere must produce prompt charged pions, whose chain decays are source of a solar (electron muon) neutrino 'flare' (at tens or hundreds MeV energy). These brief (minutes) neutrino 'bursts' at largest flare peak may overcome by three to five orders of magnitude the steady atmospheric neutrino noise on the Earth, possibly leading to their detection above detection thresholds (in a full mixed three flavour state). Moreover the birth of anti-neutrinos at a few tens of MeV very clearly flares above a null thermal 'hep' anti-neutrino solar background and also above a tiny supernova relic and atmospheric noise. The largest prompt solar anti-neutrino 'burst' may be well detected in future Super Kamikande (gadolinium implemented) anti-neutrino \\bar\

  19. Electron Neutrino and Antineutrino Appearance in the MINOS Detector

    Energy Technology Data Exchange (ETDEWEB)

    Schreckenberger, Adam Paul [Univ. of Minnesota, Minneapolis, MN (United States)

    2013-04-01

    The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline neutrino experiment that utilizes a particle beam and two steel-scintillator calorimeters designed to determine the parameters associated with muon neutrino disappearance. Analysis methods developed by the MINOS νe group have facilitated the placement of limits upon the mixing angle associated with νμ → νe oscillations. Since the polarity of the focusing horns can be switched, we can perform a similar analysis with an antineutrino-enriched beam to select electron antineutrino appearance candidates. Using 3.34e20 POT (protons on target) in the antineutrino mode, we exclude θ13 = 0 at the 80% C.L. A joint fit of the 3.34e20 POT antineutrino and 10.6e20 POT neutrino samples excluded θ13 = 0 at the 96% C.L. In addition, the combined data were used to produce exclusions regarding the CP-violating phase.

  20. Towards earth AntineutRino TomograpHy (EARTH)

    NARCIS (Netherlands)

    De Meijer, R. J.; Smit, F. D.; Brooks, F. D.; Fearick, R. W.; Wortche, H. J.; Mantovani, F.

    2006-01-01

    The programme Earth AntineutRino TomograpHy (EARTH) proposes to build ten underground facilities each hosting a telescope. Each telescope consists of many detector modules, to map the radiogenic heat sources deep in the interior of the Earth by utilising direction sensitive geoneutrino detection.

  1. Active neutral particle diagnostics on LHD by locally enhanced charge exchange on an impurity pellet ablation cloud

    International Nuclear Information System (INIS)

    Goncharov, P.R.; Ozaki, T.; Sudo, S.; Tamura, N.; Kalinina, D.V.; Veshchev, E.A.

    2005-01-01

    Production, confinement and thermalization of high-energy particles are the fundamental issues in fusion plasma ion kinetics. The ion distribution function and its evolution under the ion cyclotron heating and neutral beam injection are studied by energy resolved charge exchange neutral flux measurements. For helical systems, such as LHD, local diagnostics are required due to the complex 3D magnetic field. In passive methods one needs to analyze the integral relation between the plasma ion distribution function and the observed neutral flux, which is a superposition along the diagnostic sightline, taking into account the charge exchange target density profile. In active measurements either a diagnostic neutral beam or a solid pellet injection are used to enhance the charge exchange locally. An impurity pellet ablation cloud r cloud plasma provides a localized charge exchange target scanning the plasma radially. Pellet-induced neutral fluxes were previously measured on LHD with a natural diamond detector. However, obtaining the energy spectra from these data in the main energy range of interest (10 1 -10 2 keV in the present experiments) is complicated due to the high operating speed, i.e. the spatial resolution requirement. A new diagnostic based on a compact neutral particle analyser (CNPA) has been installed on LHD for measurements in the H 0 energy range 1 - 170 keV. CNPA employs a thin 50 A diamond-like carbon stripping film instead of a traditional gas stripping cell, a high-field-strength permanent analysing magnet and an array of 40 channel electron multipliers (CEMs) for particle detection. CEMs can be used in both counting and current modes to be able to process high neutral particle fluxes from the charge exchange on the dense pellet cloud. Thus, the system is suitable for both passive measurements and the active probing with a diagnostic pellet. Pneumatically accelerated polystyrene (-C 8 H 8 -) n balls are injected transversally; typical D pel = 500

  2. Critical validity assessment of theoretical models: charge-exchange at intermediate and high energies

    Science.gov (United States)

    Belkić, Dževad

    1999-06-01

    Exact comprehensive computations are carried out by means of four leading second-order approximations yielding differential cross sections dQ/ dΩ for the basic charge exchange process H ++H(1s)→H(1s)+H + at intermediate and high energies. The obtained extensive set of results is thoroughly tested against all the existing experimental data with the purpose of critically assessing the validity of the boundary corrected second-Born (CB2), continuum-distorted wave (CDW), impulse approximation (IA) and the reformulated impulse approximation (RIA). The conclusion which emerges from this comparative study clearly indicates that the RIA agrees most favorably with the measurements available over a large energy range 25 keV-5 MeV. Such a finding reaffirms the few-particle quantum scattering theory which imposes several strict conditions on adequate second-order methods. These requirements satisfied by the RIA are: (i) normalisations of all the scattering wave functions, (ii) correct boundary conditions in both entrance and exit channels, (iii) introduction of a mathematically justified two-center continuum state for the sum of an attractive and a repulsive Coulomb potential with the same interaction strength, (iv) inclusion of the multiple scattering effects neglected in the IA, (v) a proper description of the Thomas double scattering in good agreement with the experiments and without any unobserved peak splittings. Nevertheless, the performed comparative analysis of the above four approximations indicates that none of the methods is free from some basic shortcomings. Despite its success, the RIA remains essentially a high-energy model like the other three methods under study. More importantly, their perturbative character leaves virtually no room for further systematic improvements, since the neglected higher-order terms are prohibitively tedious for practical purposes and have never been computed exactly. To bridge this gap, we presently introduce the variational Pad

  3. Critical validity assessment of theoretical models: charge-exchange at intermediate and high energies

    International Nuclear Information System (INIS)

    Belkic, Dzevad

    1999-01-01

    Exact comprehensive computations are carried out by means of four leading second-order approximations yielding differential cross sections dQ/dΩ for the basic charge exchange process H + +H(1s)→H(1s)+H + at intermediate and high energies. The obtained extensive set of results is thoroughly tested against all the existing experimental data with the purpose of critically assessing the validity of the boundary corrected second-Born (CB2), continuum-distorted wave (CDW), impulse approximation (IA) and the reformulated impulse approximation (RIA). The conclusion which emerges from this comparative study clearly indicates that the RIA agrees most favorably with the measurements available over a large energy range 25 keV-5 MeV. Such a finding reaffirms the few-particle quantum scattering theory which imposes several strict conditions on adequate second-order methods. These requirements satisfied by the RIA are: (i) normalisations of all the scattering wave functions, (ii) correct boundary conditions in both entrance and exit channels, (iii) introduction of a mathematically justified two-center continuum state for the sum of an attractive and a repulsive Coulomb potential with the same interaction strength, (iv) inclusion of the multiple scattering effects neglected in the IA, (v) a proper description of the Thomas double scattering in good agreement with the experiments and without any unobserved peak splittings. Nevertheless, the performed comparative analysis of the above four approximations indicates that none of the methods is free from some basic shortcomings. Despite its success, the RIA remains essentially a high-energy model like the other three methods under study. More importantly, their perturbative character leaves virtually no room for further systematic improvements, since the neglected higher-order terms are prohibitively tedious for practical purposes and have never been computed exactly. To bridge this gap, we presently introduce the variational Pade

  4. Modeling the Magnetospheric X-ray Emission from Solar Wind Charge Exchange with Verification from XMM-Newton Observations

    Science.gov (United States)

    2016-08-26

    Earth (i.e., hydrogen) to a heavy , high charge state, ion in the solarwind. The electron can be captured in an excited state and transition to lower... heavy ions , Geophys Res. Lett., 24, 105–109, doi:10.1029/96GL03780. Cravens, T. E. (2000), Heliospheric X-ray emission associated with charge transfer...quantifying charge exchange from other ions with emission lines around the 1 4 keV band have also been performed, though the lack of cross-sectional

  5. Initial Assessment of Electron and X-Ray Production and Charge Exchange in the NDCX-II Accelerator

    International Nuclear Information System (INIS)

    Cohen, R.H.

    2010-01-01

    The purpose of this note is to provide initial assessments of some atomic physics effects for the accelerator section of NDCX-II. There are several effects we address: the production of electrons associated with loss of beam ions to the walls, the production of electrons associated with ionization of background gas, the possibly resultant production of X-rays when these electrons hit bounding surfaces, and charge exchange of beam ions on background gas. The results presented here are based on a number of caveats that will be stated below, which we will attempt to remove in the near future.

  6. Prospects of real-time ion temperature and rotation profiles based on neural-network charge exchange analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, R.W.T.; Von Hellermann, M. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Svensson, J. [Royal Inst. of Tech., Stockholm (Sweden)

    1994-07-01

    A back-propagation neural network technique is used at JET to extract plasma parameters like ion temperature, rotation velocities or spectral line intensities from charge exchange (CX) spectra. It is shown that in the case of the C VI CX spectra, neural networks can give a good estimation (better than +-20% accuracy) for the main plasma parameters (Ti, V{sub rot}). Since the neural network approach involves no iterations or initial guesses the speed with which a spectrum is processed is so high (0.2 ms/spectrum) that real time analysis will be achieved in the near future. 4 refs., 8 figs.

  7. Anti-neutrino flux in a research reactor for non-proliferation application

    Energy Technology Data Exchange (ETDEWEB)

    Khakshournia, Samad; Foroughi, Shokoufeh [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of). Atomic Energy Organization of Iran (AEOI)

    2017-11-15

    Owing to growing interest in the study of emitted antineutrinos from nuclear reactors to test the Atomic Energy Agency safeguards, antineutrino flux was studied in the Tehran Research Reactor (TRR) using ORIGEN code. According to our prediction, antineutrino rate was obtained 2.6 x 10{sup 17} (v{sub e}/sec) in the core No. 57F of the TRR. Calculations indicated that evolution of antineutrino flux was very slow with time and the performed refueling had not an observable effect on antineutrino flux curve for a 5 MW reactor with the conventional refueling program. It is seen that for non-proliferation applications the measurement of the contribution of {sup 239}Pu to the fission using an antineutrino detector is not viable in the TRR.

  8. Measuring of fissile isotopes partial antineutrino spectra in direct experiment at nuclear reactor

    OpenAIRE

    Sinev, V. V.

    2009-01-01

    The direct measuring method is considered to get nuclear reactor antineutrino spectrum. We suppose to isolate partial spectra of the fissile isotopes by using the method of antineutrino spectrum extraction from the inverse beta decay positron spectrum applied at Rovno experiment. This admits to increase the accuracy of partial antineutrino spectra forming the total nuclear reactor spectrum. It is important for the analysis of the reactor core fuel composition and could be applied for non-prol...

  9. A neutrino (antineutrino)-induced four lepton event

    International Nuclear Information System (INIS)

    Loveless, R.J.; Benada, R.; Camerini, U.; Duffy, M.; Fry, W.; McCabe, P.; Minette, D.; Ngai, M.; Reeder, D.D.; Cence, R.J.; Harris, F.A.; Jones, M.D.; Parker, S.I.; Peters, M.W.; Peterson, V.Z.; Wyatt, N.; Burnett, T.H.; Holmgren, D.; Lubatti, H.J.; Moriyasu, K.; Rudnicka, H.; Swider, G.M.; Wolin, E.; Yuldashev, B.S.

    1978-01-01

    Observation of a neutrino (antineutrino)-induced event with two electrons, one positron, one positively charged muon, a neutral K meson, and seven gammas in an experiment performed in the FNAL 15-ft bubble chamber with a 47% atomic mixture of neon in hydrogen is reported. Estimated experimental electron backgrounds are approximately 10 -4 per track. At present the authors have no plausible interpretation of this event. (Auth.)

  10. Development of the gas puff charge exchange recombination spectroscopy (GP-CXRS) technique for ion measurements in the plasma edge

    International Nuclear Information System (INIS)

    Churchill, R. M.; Theiler, C.; Lipschultz, B.; Dux, R.; Pütterich, T.; Viezzer, E.

    2013-01-01

    A novel charge-exchange recombination spectroscopy (CXRS) diagnostic method is presented, which uses a simple thermal gas puff for its donor neutral source, instead of the typical high-energy neutral beam. This diagnostic, named gas puff CXRS (GP-CXRS), is used to measure ion density, velocity, and temperature in the tokamak edge/pedestal region with excellent signal-background ratios, and has a number of advantages to conventional beam-based CXRS systems. Here we develop the physics basis for GP-CXRS, including the neutral transport, the charge-exchange process at low energies, and effects of energy-dependent rate coefficients on the measurements. The GP-CXRS hardware setup is described on two separate tokamaks, Alcator C-Mod and ASDEX Upgrade. Measured spectra and profiles are also presented. Profile comparisons of GP-CXRS and a beam based CXRS system show good agreement. Emphasis is given throughout to describing guiding principles for users interested in applying the GP-CXRS diagnostic technique

  11. A Markov chain approach to modelling charge exchange processes of an ion beam in monotonically increasing or decreasing potentials

    International Nuclear Information System (INIS)

    Shrier, O; Khachan, J; Bosi, S

    2006-01-01

    A Markov chain method is presented as an alternative approach to Monte Carlo simulations of charge exchange collisions by an energetic hydrogen ion beam with a cold background hydrogen gas. This method was used to determine the average energy of the resulting energetic neutrals along the path of the beam. A comparison with Monte Carlo modelling showed a good agreement but with the advantage that it required much less computing time and produced no numerical noise. In particular, the Markov chain method works well for monotonically increasing or decreasing electrostatic potentials. Finally, a good agreement is obtained with experimental results from Doppler shift spectroscopy on energetic beams from a hollow cathode discharge. In particular, the average energy of ions that undergo charge exchange reaches a plateau that can be well below the full energy that might be expected from the applied voltage bias, depending on the background gas pressure. For example, pressures of ∼20 mTorr limit the ion energy to ∼20% of the applied voltage

  12. Improved charge-coupled device detectors for high-speed, charge exchange spectroscopy studies on the DIII-D tokamak

    International Nuclear Information System (INIS)

    Burrell, K.H.; Gohil, P.; Groebner, R.J.; Kaplan, D.H.; Robinson, J.I.; Solomon, W.M.

    2004-01-01

    Charge exchange spectroscopy is one of the key ion diagnostics on the DIII-D tokamak. It allows determination of ion temperature, poloidal and toroidal velocity, impurity density, and radial electric field E r throughout the plasma. For the 2003 experimental campaign, we replaced the intensified photodiode array detectors on the central portion of the DIII-D charge exchange spectroscopy system with advanced charge-coupled device (CCD) detectors mounted on faster (f/4.7) Czerny-Turner spectrometers equipped with toroidal mirrors. The CCD detectors are improved versions of the ones installed on our edge system in 1999. The combination improved the photoelectron signal level by about a factor of 20 and the signal to noise by a factor of 2-8, depending on the absolute signal level. The new cameras also allow shorter minimum integration times while archiving to PC memory: 0.552 ms for the slower, lower-read noise (15 e) readout mode and 0.274 ms in the faster, higher-read noise (30 e) mode

  13. Antineutrino Neutral Current Interactions in MiniBooNE

    Energy Technology Data Exchange (ETDEWEB)

    Dharmapalan, Ranjan [Univ. of Alabama, Tuscaloosa, AL (United States)

    2012-01-01

    This dissertation reports the antineutrino-nucleus neutral current elastic scattering cross section on CH2 measured by the MiniBooNE experiment located in Batavia, IL. The data set consists of 60,605 events passing the selection cuts corresponding to 10.1×1020 POT, which represents the world’s largest sample of antineutrino neutral current elastic scattering events. The final sample is more than one order of magnitude lager that the previous antineutrino NCE scattering cross section measurement reported by the BNL E734 experiment. The measurement presented in this dissertation also spans a wider range in Q2, including the low-Q2 regime where the cross section rollover is clearly visible. A X2-based minimization was performed to determine the best value of the axial mass, MA and the Pauli blocking scaling function, that matches the antineutrino NCE scattering data. However, the best fit values of MA=1.29 GeV and K=1.026 still give a relatively poor X2, which suggests that the underlying nuclear model (based largely on the relativistic Fermi gas model) may not be an accurate representation for this particular interaction. Additionally, we present a measurement of the antineutrino/neutrino-nucleus NCE scattering cross section ratio. The neutrino mode NCE sample used in this study, corresponding to 6.4 × 1020 POT, is also the world’s largest sample (also by an order of magnitude). We have demonstrated that the ratio measurement is robust, as most of the correlated errors cancel, as expected. Furthermore, this ratio also proves to be rather insensitive to variations in the axial mass and the Pauli blocking parameter. This is the first time that this ratio has been experimentally reported. We believe this measurement will aid the theoretical physics community to test various model predictions of neutrino-nucleon/nucleus interactions.

  14. Use of Antineutrino Detectors for Nuclear Reactor Safeguards Effectiveness Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, A; Lambert, H E; Elayat, H A; O' Connell, W J; Rexroth, P; Baldwin, G; Bowden, N; Huelskamp, R

    2006-06-05

    As described in an earlier article [1], important information regarding reactor power and the amount and type of fissile material in reactor cores can be determined by measuring the antineutrino rate and energy spectrum, using a cubic meter scale antineutrino detector at tens of meters standoff from the core. Current International Atomic Energy Agency (IAEA) safeguards techniques do not provide such real-time quantitative information regarding core power levels and isotopic composition. The possible benefits of this approach are several and have been discussed in the earlier article. One key advantage is that the method gives the inspecting agency completely independent access to real-time information on the operational status and fissile content of the core. Furthermore, the unattended and non-intrusive nature of the technology may reduce the monitoring burden on the plant operator, even though more information is being provided than is available within the current IAEA safeguards regime. Here we present a detailed analytical framework for measuring the impact that such a detector might have on IAEA safeguards, if implemented. To perform the analysis, we will use initial data from our operating detector and a standard analysis technique for safeguards regimes, developed at Lawrence Livermore National Laboratory. Because characterization of the prototype detector is still underway, and because improvements in the prototype could have important impact on safeguards performance, the results presented here should be understood to be preliminary, and not reflective of the ultimate performance of the system. The structure of this paper is as follows. Reactor safeguards and the relevant properties of antineutrino detectors are briefly reviewed. A set of hypothetical diversion scenarios are then described, and one of these is analyzed using the Lawrence Livermore National Laboratory Integrated Safeguards System Analysis Tool (LISSAT) The probability of successful

  15. Leakage Tests of the Stainless Steel Vessels of the Antineutrino Detectors in the Daya Bay Reactor Neutrino Experiment

    OpenAIRE

    Chen, Xiaohui; Luo, Xiaolan; Heng, Yuekun; Wang, Lingshu; Tang, Xiao; Ma, Xiaoyan; Zhuang, Honglin; Band, Henry; Cherwinka, Jeff; Xiao, Qiang; Heeger, Karsten M.

    2012-01-01

    The antineutrino detectors in the Daya Bay reactor neutrino experiment are liquid scintillator detectors designed to detect low energy particles from antineutrino interactions with high efficiency and low backgrounds. Since the antineutrino detector will be installed in a water Cherenkov cosmic ray veto detector and will run for 3 to 5 years, ensuring water tightness is critical to the successful operation of the antineutrino detectors. We choose a special method to seal the detector. Three l...

  16. Reactors as a source of antineutrinos: the effect of fuel loading and burnup for mixed oxide fuels

    OpenAIRE

    Bernstein, Adam; Bowden, Nathaniel; Erickson, Anna

    2016-01-01

    In a conventional light water reactor loaded with a range of uranium and plutonium-based fuel mixtures, the variation in antineutrino production over the cycle reflects both the initial core fissile inventory and its evolution. Under the assumption of constant thermal power, we calculate the rate at which antineutrinos are emitted from variously fueled cores, and the evolution of that rate as measured by a representative ton-scale antineutrino detector. We find that antineutrino flux decrease...

  17. Measurement and Calculation of Absolute Single- and Multiple-Charge-Exchange Cross Sections for Feq+ Ions Impacting CO and CO2

    Energy Technology Data Exchange (ETDEWEB)

    Simcic, J. [Jet Propulsion Laboratory/Caltech; Schultz, David Robert [ORNL; Mawhorter, R. J. [Pomona College; Cadez, I. [Jozef Stefan Institute, Slovenia; Greenwood, J. B. [Queen' s University, Belfast; Chutjian, A. [Jet Propulsion Laboratory/Caltech; Lisse, Carey M. [Johns Hopkins University; Smith, S. J. [Indiana Wesleyan University, Marion

    2010-01-01

    Absolute cross sections are reported for single, double, and triple charge exchange of Feq+ (q=5- 13) ions with CO and CO2. The highly-charged Fe ions are generated in an electron cyclotron resonance ion source. Absolute data are derived from knowledge of the target gas pressure, target path length, and incident and charge-exchanged ion currents. Experimental results are compared with new calculations of these cross sections in the n-electron classical trajectory Monte-Carlo approximation, in which the ensuing radiative and non-radiative cascades are approximated with scaled hydrogenic transition probabilities and scaled Auger rates. The present data are needed in astrophysical applications of solar- and stellar-wind charge-exchange with comets, planetary atmospheres, and circumstellar clouds.

  18. Charge exchange and fine structure excitation in O-H+ collisions

    International Nuclear Information System (INIS)

    Chambaud, G.; Levy, B.; Millie, P.; Tran Minh, F.; Launay, J.M.; Roueff, E.

    1980-01-01

    The authors re-examine the charge-transfer reaction between protons and oxygen atoms including the fine-structure excitation process, basing the analysis on a careful description of the different potential curves arising from the O-H + and O + -H systems and on the evaluation of the coupling responsible for the transitions. (Auth.)

  19. Antineutrino Oscillations and a Search for Non-standard Interactions with the MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Isvan, Zeynep [Univ. of Pittsburgh, PA (United States)

    2012-01-01

    MINOS searches for neutrino oscillations using the disappearance of muon neutrinos from the NuMI beam at Fermilab between two detectors. The Near Detector, located near the source, measures the beam composition before flavor change occurs. The energy spectrum is measured again at the Far Detector after neutrinos travel a distance. The mixing angle and mass splitting between the second and third mass states are extracted from the energy dependent difference between the spectra at the two detectors. NuMI is able to produce an antineutrino-enhanced beam as well as a neutrino-enhanced beam. Collecting data in antineutrino-mode allows the direct measurement of antineutrino oscillation parameters. From the analysis of the antineutrino mode data we measure $|\\Delta\\bar{m}^{2}_{\\text{atm}}| = 2.62^{+0.31}_{-0.28}\\times10^{-3}\\text{eV}^{2}$ and $\\sin^{2}(2\\bar{\\theta})_{23} = 0.95^{+0.10}_{-0.11}$, which is the most precise measurement of antineutrino oscillation parameters to date. A difference between neutrino and antineutrino oscillation parameters may indicate new physics involving interactions that are not part of the Standard Model, called non-standard interactions, that alter the apparent disappearance probability. Collecting data in neutrino and antineutrino mode independently allows a direct search for non-standard interactions. In this dissertation non-standard interactions are constrained by a combined analysis of neutrino and antineutrino datasets and no evidence of such interactions is found.

  20. Search for the Neutrino Magnetic Moment in the Non-Equilibrium Reactor Antineutrino Energy Spectrum

    OpenAIRE

    Kopeikin, V. I.; Mikaelyan, L. A.; Sinev, V. V.

    1999-01-01

    We study the time evolution of the typical nuclear reactor antineutrino energy spectrum during reactor ON period and the decay of the residual antineutrino spectrum after reactor is stopped. We find that relevant variations of the soft recoil electron spectra produced via weak and magnetic ${\\widetilde {\

  1. The upper limit of the solar antineutrino flux according to the LSD array data

    International Nuclear Information System (INIS)

    Al'etta, M.; Antonioli, P.; Badino, D.

    1997-01-01

    The analysis of the experimental data obtained at the LSD liquid scintillation detector is carried out with the aim of searching the possible flux of electron antineutrinos from Sun. The most strong at present upper limit for the electron antineutrino flux of solar origin is determined: ≤ 1.0 x 10 5 cm -2 x s -1 (the reliability level of 90%)

  2. Fast charge exchange spectroscopy using a Fabry-Perot spectrometer in the JIPP TII-U tokamak

    International Nuclear Information System (INIS)

    Ida, K.; Xu, J.; Sato, K.N.; Sakakita, H.

    1997-01-01

    A new charge exchange spectroscopic technique using a Fabry-Port spectrometer has been developed to increase the photon flux at the detector, and to improve the time resolution of ion temperature and plasma rotation velocity measurements. The spectral resolution is obtained by arranging two-dimensional fiber-optics and a two-dimensional detector at the focal plane of a coupled lens located on both sides of a Fabry-Perot spectrometer. The effective finesse (the ratio of the spectral resolution to the free spectral range) of the Fabry-Perot interferometer in this system is 14. The time evolution of the ion temperature is obtained with a time resolution of 125 μs and with a spatial resolution of 3 cm (eight channels). (orig.)

  3. A microscopic approach based on particle-vibration coupling: application to charge-exchange transitions and multiplets in odd nuclei

    Directory of Open Access Journals (Sweden)

    Colò Gianluca

    2016-01-01

    Full Text Available In this contribution, we shall describe a formalism that goes beyond the simple time-dependent mean field and is based on particle-vibration coupling (PVC. Such a formalism has been developed with the idea of being self-consistent. It makes use of Skyrme effective forces, and has been used for several applications. We will focus on charge-exchange transitions, namely we will show that our model describes well both the Gamow-Teller giant resonance width, and the low-lying transitions associated with β-decay. In this latter case, including PVC produces a significant improvement of the half-lives obtained at mean-field level, and leads to a good agreement with experimental data. We will end by discussing particle-phonon multiplets in odd nuclei.

  4. Observation of Solar Wind Charge Exchange Emission From Exospheric Material in and Outside Earth's Magnetosheath 2008 September 25

    Science.gov (United States)

    Snowden, S. L.; Collier, M. R.; Cravens, T.; Kuntz, K. D.; Lepri, S. T.; Robertson, I.; Tomas, L.

    2009-01-01

    A long XMM-Newton exposure is used to observe solar wind charge exchange (SWCX) emission from exospheric material in and outside Earth's magnetosheath. The light curve of the O vii (0.5-0.62 keV) band is compared with a model for the expected emission, and while the emission is faint and the light curve has considerable scatter, the correlation is significant to better than 99.9%. This result demonstrates the validity of the geocoronal SWCX emission model for predicting a contribution to astrophysical observations to a scale factor of order unity (1.5). In addition, an average value of the SWCX O vii emission from the magnetosheath over the observation of 2.6 +/- 0.5 LU is derived. The results also demonstrate the potential utility of using X-ray observations to study global phenomena of the magnetosheath which currently are only investigated using in situ measurements.

  5. Charge-exchange measurements of beam ion thermalization in MHD-quiescent plasmas in the Poloidal Divertor Experiment

    International Nuclear Information System (INIS)

    Kaita, R.; Goldston, R.J.; Beiersdorfer, P.

    1984-10-01

    The horizontally scanning, multiangle charge-exchange analyzer on the Poloidal Divertor Experiment (PDX) was used to study the beam ion slowing-down process with high-power perpendicular injection. Measurements were made over a wide range in toroidal field (8 kG < B(T) < 22 kG), plasma current (200 kA < I(p) < 500 kA), and beam power (1 MW < P/sub B/ < 7 MW). In MHD-quiescent plasmas, good agreement is found between the measured slowing-down spectra and theoretical predictions as a function of both angle and energy. Classes of prompt orbit losses are observed with both co- and counter-injection which have been understood and applied to plasma diagnostics. The effects of MHD activity on fast ion thermalization will be the subject of a companion paper

  6. Role of wall implantation of charge exchange neutrals in the deuterium retention for Tore Supra long discharges

    International Nuclear Information System (INIS)

    Tsitrone, E.; Reiter, D.; Loarer, T.; Brosset, C.; Bucalossi, J.; Begrambekov, L.; Grisolia, C.; Grosman, A.; Gunn, J.; Hogan, J.; Mitteau, R.; Pegourie, B.; Ghendrih, P.; Reichle, R.; Roubin, P.

    2005-01-01

    In Tore Supra long pulses, particle balance gives evidence that a constant fraction of the injected gas (typically 50%) is retained in the wall for the duration of the shot, showing no sign of wall saturation after more than 6 min of discharge. During the discharge, the retention rate first decreases (phase 1), then remains constant throughout the pulse (phase 2). Phase 1 could be interpreted as implantation of particles combined with a constant codeposition rate, while phase 2 could correspond to codeposition alone, once the implanted surfaces are saturated with deuterium. This paper presents a possible contribution of charge exchange neutrals to the implantation process, based on modelling results with the Eirene neutral transport code. A complex pattern of particle implantation is evidenced, with saturation time constants ranging from less than one to several hundreds seconds, compatible with the experimental behaviour during phase 1

  7. Study of the mass and energy resolution of the E parallel B charge exchange analyzer for TFTR

    International Nuclear Information System (INIS)

    Kaita, R.; Medley, S.S.

    1979-09-01

    The charge exchange diagnostic for TFTR requires simultaneous multispecie (H + , D + , γ + ) analysis of particles in the energy range of 0.5 - 150 keV. The analyzer design chosen to provide this capability employs a wide gap semi-circular region of superimposed parallel electric and magnetic fields to accomplish mass and energy resolution, respectively. Combined with a large area, multi-anode microchannel plate detector, this arrangement will enable the energy distributions of protons, deuterions, and tritons to be measured concurrently as a function of time during each discharge. A computer simulation program for calculating ion trajectories through the analyzer was written that includes a realistic model of the magnetic and electrostatic fringe fields. This report presents the results of a study of the proposed E parallel B analyzer, and it reveals that the fringe fields are not detrimental to the performance of the analyzer

  8. Charge Exchange in Low-Energy H, D + C4+ Collisions with Full Account of Electron Translation

    Directory of Open Access Journals (Sweden)

    N. Vaeck

    2002-03-01

    Full Text Available We report the application of the quantum approach, which takes full account of electron translation at low collisional energies, to the charge exchange process H, D + C4+ → H+, D+ + C3+(3s; 3p; 3d. The partial and the total integral cross sections of the process are calculated in the energy range from 1 till 60 eV/amu. It is shown that the present results are independent from the upper integration limit for numerical solution of the coupled channel equations although nonadiabatic couplings remain nonzero up to infinity. The calculated partial and total cross sections are in agreement with the previous low-energy calculations and the available experimental data. It is shown that for low collisional energies the isotopic effect takes place. The observed effect is explained in terms of the nonadiabatic dynamics.

  9. Charge exchange laboratory studies relevant to solar-wind-induced cometary and planetary X-ray emission

    Science.gov (United States)

    Eissa, Farhat

    The discovery of cometary X-ray emission for the first time in 1996, from comet Hyukatake using the Röntgen satellite (ROSAT) [Lisse, C. M. et al., 1996] was a highly surprising event. Since then, X-ray and extreme ultra violet (X-EUV) emission has been observed from a number of comets [Lisse, C. M. et al., 2001]. The production of such radiation is strongly believed to be the result of the charge exchange collisions of the minor heavy highly charged solar wind (SW) ions with cometary neutrals. This study reports the first state-selective He- like X-ray spectra resulting from single-electron capture (SEC) in charge exchange collisions of O 7+ and Ne 9+ with He and CO targets at a collision velocity of 800 km/s. The ions and velocity are typical of solar wind ions while the molecular and atomic targets are typical of cometary (CO) and interstellar (He) neutrals. The spectra have been obtained by means of simultaneous cold-target recoil ion momentum spectroscopic (COLTRIMS) and X-ray spectroscopic measurements that involved the triple-coincident detection of X- rays, scattered projectile, and target recoil ions. The spectra test the ability of theories to account for the relative population of triplet and singlet states in He-like product ions following SEC. The O 7+ +He spectra are compared with theoretical spectra based on quantal molecular-orbital close- coupling (QMOCC) and multi-channel Landau-Zener (MCLZ) calculations. In addition, all spectra have been used to extract angular momentum distributions based on the traditional 3:1 triplet-to-singlet ratio assumption for the populated states. The QMOCC and MCLZ calculations and the experimental results, however, suggest significant departures from this assumption. The extracted l - distributions are state-of-the-art at this time for modeling purposes due to the high differentiation power of the experimental procedure.

  10. Pion-nucleon charge-exchange polarization by Gribov Reggeon calculus and the derivative rule

    International Nuclear Information System (INIS)

    Ardill, R.W.B.; Koehler, P.; Moriarty, K.J.M.

    1977-01-01

    The phenomenological consequences of the Gribov Reggeon calculus for the reaction πsup(-)+p→πdeg+n at 6 GeV/c are investigated and the polarization is obtained. The derivative rules is used to calculate the helicity flip amplitude. The results are very encouraging and would seem to indicate that the Gribov Reggeon calculus can be considered a more satisfactory approach to two-body phenomenology than the absorption model

  11. Dilepton and trilepton production by antineutrinos and neutrinos in neon

    Science.gov (United States)

    Gerbier, G.; Bertrand, D.; Guy, J.; Marage, P.; Aderholz, M.; Armenise, N.; Bartley, J. H.; Baton, J. P.; Brisson, V.; Belusevic, R.; Brou, D.; Bullock, F. W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Klein, H.; Kochowski, C.; Lagraa, M.; Leighton-Davis, S.; Middleton, R.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; Nuzzo, S.; O'Neale, S.; Parker, M. A.; Petiau, P.; Sacton, J.; Sansum, R. A.; Schmitz, N.; Simopoulou, E.; Talebzadeh, M.; Varvell, K.; Vallee, C.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wells, J.; Wittek, W.; Zevgolatakos, E.

    1985-03-01

    A sample of over 25,000 fully measured neutrino and antineutrino charged current interactions in BEBC includes 192 dilepton candidates. The prompt signal after subtraction of background is 41 ±7µ+ e -, 35±7µ+µ- events frombar v interactions, and 32±7µ-µ+ events from ν interactions. There are 2 trileptons, µ-µ- e + and µ-µ-µ+. Results are compared with other experimental data and with the standard model. Limits to prompt like sign µ+ e +, µ+µ+ and µ-µ- signals are given and compared with other experiments and with theoretical calculations.

  12. pi-N charge exchange and pi(+)-pi(0) scattering at low energies

    OpenAIRE

    Pocanic, D.; Frlez, E.

    1997-01-01

    pi-N and pi-pi interactions near threshold are uniquely sensitive to the chiral symmetry breaking part of the strong interaction. The pi-N sigma-term value with its implications for nucleon quark structure and the recent controversy concerning the size of the scalar quark condensate have renewed the experimental interest in these two fundamental systems. We report new differential cross sections for the reaction $pi^-p \\to \\pi^0n$ at 27.5 MeV pion incident kinetic energy, measured between $\\t...

  13. Charge exchange transition probability for collisions between unlike ions and atoms within the adiabatic approximation

    Science.gov (United States)

    Xu, Y. J.; Khandelwal, G. S.; Wilson, John W.

    1989-01-01

    A simple formula for the transition probability for electron exchange between unlike ions and atoms is established within the adiabatic approximation by employing the Linear Combination of Atomic Orbitals (LCAO) method. The formula also involves an adiabatic parameter, introduced by Massey, and thus the difficulties arising from the internal energy defect and the adiabatic approximation are avoided. Specific reactions Li(+++) + H to Li(++) + H(+) and Be(4+) + H to Be(3+) + H(+) are considered as examples. The calculated capture cross section results of the present work are compared with the experimental data and with the calculation of other authors over the velocity range of 10(7) cm/sec to 10(8) cm/sec.

  14. Chandra observations of comet 2P/Encke 2003 : First detection of a collisionally thin, fast solar wind charge exchange system

    NARCIS (Netherlands)

    Lisse, CM; Christian, DJ; Dennerl, K; Wolk, SJ; Bodewits, Dennis; Hoekstra, Ronnie; Combi, MR; Makinen, T; Dryer, M; Fry, CD; Weaver, H

    2005-01-01

    We report the results of 15 hr of Chandra observations of comet 2P/Encke 2003 on November 24. X-ray emission from comet Encke was resolved on scales of 500-40,000 km, with unusual morphology due to the presence of a low-density, collisionally thin (to charge exchange) coma. A light curve with

  15. Review of Langmuir-wave-caused dips and charge-exchange-caused dips in spectral lines from plasmas and their applications

    Czech Academy of Sciences Publication Activity Database

    Dalimier, E.; Oks, E.; Renner, Oldřich

    2014-01-01

    Roč. 2, č. 2 (2014), s. 178-194 ISSN 2218-2004 Grant - others:AVČR(CZ) M100101208 Institutional support: RVO:68378271 Keywords : Laser-matter interaction * spectral line profiles * Langmuir waves * plasma electron density * charge exchange rates Subject RIV: BL - Plasma and Gas Discharge Physics

  16. Polarization in K+n charge exchange scattering between 0.851 GeV/c and 1.351 GeV/c

    International Nuclear Information System (INIS)

    Watts, S.J.; Bugg, D.V.; Carter, A.A.; Coupland, M.; Eisenhandler, E.; Gibson, W.R.; Kalmus, P.I.P.; Sandhu, H.; Astbury, A.; Grayer, G.H.

    1980-01-01

    The polarization parameter for K + n charge exchange scattering has been measured at five momenta between 0.851 GeV/c and 1.351 GeV/c for centre of mass angles -0.8 < cos theta* < 0.8. Results from a phase shift analysis incorporating these results are presented. No Z* resonances are onserved. (orig.)

  17. Pion double charge exchange above the Δ3/2,3/2 resonance

    International Nuclear Information System (INIS)

    Williams, A.L.

    1991-11-01

    The first exclusive measurements of (π + π - ) reactions on several nuclei for incident pion energies from 300 to 550 MeV are reported. The measurements were made with the Large Acceptance Spectrometer at the P 3 channel of the Clinton P. Anderson Meson Physics Facility. A description of the experimental setup is given which includes a discussion of modifications to the spectrometer and channel implemented specifically for these measurements. Forward angle excitation functions for transitions to the double isobaric analog state (DIAS) are found to be relatively flat for these energies. This energy dependence is reproduced by optical and Glauber calculations, but not by a six-quark bag prediction. The mass dependence of the DIAS was found to qualitatively agree with the predicted mass dependence from optical calculations. One angular distribution was measured for 5 degrees ≤ Θ lab ≤ 35 degrees for 18 O(π + π - ) 18 Ne. The DIAS cross section falls by more than one order of magnitude over this range, as predicted by both Glauber and optical model calculations. Data for f 7/2 -shell nuclei were examined with a two-amplitude model based on seniority-zero shell model wavefunctions which features expressions for cross sections for DIAS transitions and transitions to nonanalog ground-states. The cross sections for T = 1 nuclei are found to be inconsistent with the predictions of the model. One excitation function for nonanalog transitions was measured and is relatively flat with energy. The continuum of nonanalog states near threshold was found to decrease with energy

  18. Search for differences in oscillation parameters for atmospheric neutrinos and antineutrinos at Super-Kamiokande.

    Science.gov (United States)

    Abe, K; Hayato, Y; Iida, T; Ikeda, M; Iyogi, K; Kameda, J; Koshio, Y; Kozuma, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Takeuchi, Y; Ueno, K; Ueshima, K; Watanabe, H; Yamada, S; Yokozawa, T; Ishihara, C; Kaji, H; Lee, K P; Kajita, T; Kaneyuki, K; McLachlan, T; Okumura, K; Shimizu, Y; Tanimoto, N; Martens, K; Vagins, M R; Labarga, L; Magro, L M; Dufour, F; Kearns, E; Litos, M; Raaf, J L; Stone, J L; Sulak, L R; Goldhaber, M; Bays, K; Kropp, W R; Mine, S; Regis, C; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Albert, J B; Scholberg, K; Walter, C W; Wendell, R; Wongjirad, T M; Tasaka, S; Learned, J G; Matsuno, S; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Nishino, H; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Minamino, A; Nakaya, T; Fukuda, Y; Itow, Y; Mitsuka, G; Tanaka, T; Jung, C K; Taylor, I; Yanagisawa, C; Ishino, H; Kibayashi, A; Mino, S; Mori, T; Sakuda, M; Toyota, H; Kuno, Y; Kim, S B; Yang, B S; Ishizuka, T; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Yokoyama, M; Totsuka, Y; Chen, S; Heng, Y; Yang, Z; Zhang, H; Kielczewska, D; Mijakowski, P; Connolly, K; Dziomba, M; Wilkes, R J

    2011-12-09

    We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande-I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best-fit antineutrino mixing is found to be at (Δm2,sin2 2θ)=(2.0×10(-3)  eV2, 1.0) and is consistent with the overall Super-K measurement.

  19. Electric charge state changing collisions of hydrogen and helium with low-Z impurity particles. Part 1. Charge exchange processes

    International Nuclear Information System (INIS)

    Tolstikhina, I.Yu.; Goncharov, P.R.; Ozaki, T.; Sudo, S.; Tamura, N.; Sergeev, V.Yu.

    2008-04-01

    This report contains a collection of practical approximating formulas for one-electron loss and one-electron capture cross-sections of ion-atom and ion-ion collisions of H 0 , H + , He 0 , He + and He 2+ particles with Li, Be, B, C and Ne neutral atoms and all of their positive ions. The report consists of two parts treating charge exchange and ion impact ionization collisions respectively. The results are mainly based on theoretical calculations by CAPTURE, CDW, and ARSENY numerical codes. Independent experimental and theoretical results were taken into account where available. The primary objective of this work is to provide the necessary background concerning atomic processes essential for localized fusion plasma diagnostics based on light impurity pellet injection. As for passive line-integral diagnostics of energetic proton and α-particle energy distribution, impurities contribute to both the source function and the attenuation rate of neutral atom fluxes escaping from the plasma. Impurities also play a significant role in the high energy neutral atom heating beam stopping in the plasma. The analytic cross-section fits for a wide energy range presented here may be useful in the numerical modeling and in the experimental data analysis. (author)

  20. Overview on R and D and design activities for the ITER core charge exchange spectroscopy diagnostic system

    Energy Technology Data Exchange (ETDEWEB)

    Biel, W., E-mail: w.biel@fz-juelich.de [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Baross, T. [KFKI RMKI, EURATOM Association, PO Box 49, H-1521 Budapest (Hungary); Bourauel, P. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Dunai, D. [KFKI RMKI, EURATOM Association, PO Box 49, H-1521 Budapest (Hungary); Durkut, M. [TNO Science and Industry, Partner in ITER-NL, P.O. Box 155, 2600 AD Delft (Netherlands); Erdei, G. [BME, EURATOM Association, PO Box 91, H-1521 Budapest (Hungary); Hawkes, N. [Association EURATOM/CCFE, OX14 3DB Abingdon (United Kingdom); Hellermann, M. von [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, partner in the Trilateral Euregio Cluster and ITER-NL, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Hogenbirk, A. [Nuclear Research and Consultancy Group V.o.F., Petten (Netherlands); Jaspers, R. [Department of Applied Physics, Eindhoven University of Technology (Netherlands); Kiss, G. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Klinkhamer, F. [TNO Science and Industry, Partner in ITER-NL, P.O. Box 155, 2600 AD Delft (Netherlands); Koning, J.F. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, partner in the Trilateral Euregio Cluster and ITER-NL, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Kotov, V.; Krasikov, Y.; Krimmer, A. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany)

    2011-10-15

    The ITER core charge exchange recombination spectroscopy (core CXRS) diagnostic system is designed to provide experimental access to various measurement quantities in the ITER core plasma such as ion densities, temperatures and velocities. The implementation of the approved CXRS diagnostic principle on ITER faces significant challenges: First, a comparatively low CXRS signal intensity is expected, together with a high noise level due to bremsstrahlung, while the requested measurement accuracy and stability for the core CXRS system go far beyond the level commonly achieved in present-day fusion experiments. Second, the lifetime of the first mirror surface is limited due to either erosion by fast particle bombardment or deposition of impurities. Finally, the hostile technical environment on ITER imposes challenging boundary conditions for the diagnostic integration and operation, including high neutron loads, electro-magnetic loads, seismic events and a limited access for maintenance. A brief overview on the R and D and design activities for the core CXRS system is presented here, while the details are described in parallel papers.

  1. The Helium Warm Breeze in IBEX Observations As a Result of Charge-exchange Collisions in the Outer Heliosheath

    Energy Technology Data Exchange (ETDEWEB)

    Bzowski, Maciej; Kubiak, Marzena A.; Czechowski, Andrzej; Grygorczuk, Jolanta, E-mail: bzowski@cbk.waw.pl [Space Research Centre PAS (CBK PAN) Bartycka 18A 00-716 Warsaw (Poland)

    2017-08-10

    We simulated the signal due to neutral He atoms, observed by the Interstellar Boundary Explorer ( IBEX ), assuming that charge-exchange collisions between neutral He atoms and He{sup +} ions operate everywhere between the heliopause and a distant source region in the local interstellar cloud, where the neutral and charged components are in thermal equilibrium. We simulated several test cases of the plasma flow within the outer heliosheath (OHS) and investigated the signal generation for plasma flows both in the absence and in the presence of the interstellar magnetic field (ISMF). We found that a signal in the portion of IBEX data identified as being due to the Warm Breeze (WB) does not arise when a homogeneous plasma flow in front of the heliopause is assumed, but it appears immediately when any reasonable disturbance in its flow due to the presence of the heliosphere is assumed. We obtained a good qualitative agreement between the data selected for comparison and the simulations for a model flow with the velocity vector of the unperturbed gas and the direction and intensity of magnetic field adopted from recent determinations. We conclude that direct-sampling observations of neutral He atoms at 1 au from the Sun are a sensitive tool for investigating the flow of interstellar matter in the OHS, that the WB is indeed the secondary population of interstellar helium, which was hypothesized earlier, and that the WB signal is consistent with the heliosphere distorted from axial symmetry by the ISMF.

  2. A study of inclusive antineutrino interactions in propane

    International Nuclear Information System (INIS)

    Ramzan, F.A.

    1979-02-01

    Some results obtained using the heavy liquid bubble chamber Gargamelle situated at the CERN Proton Synchrotron neutrino beam facility are presented. The deep inelastic scattering of antineutrinos is analysed and interpreted in the theoretical framework of Bjorken scaling and the Quark Parton model of the nucleon. This model predicts that scaling should occur in regions of high four momentum squared. The effect of not being in that region is investigated. In particular the data suggest that in the region of low four momentum transfer the results can still be interpreted in the scaling framework. A model is presented which enables extraction of the neutron to proton cross section, and the result is interpreted within the quark model. (author)

  3. Analysis of the Daya Bay Reactor Antineutrino Flux Changes with Fuel Burnup

    Science.gov (United States)

    Hayes, A. C.; Jungman, Gerard; McCutchan, E. A.; Sonzogni, A. A.; Garvey, G. T.; Wang, X. B.

    2018-01-01

    We investigate the recent Daya Bay results on the changes in the antineutrino flux and spectrum with the burnup of the reactor fuel. We find that the discrepancy between current model predictions and the Daya Bay results can be traced to the original measured U 235 /Pu 239 ratio of the fission β spectra that were used as a base for the expected antineutrino fluxes. An analysis of the antineutrino spectra that is based on a summation over all fission fragment β decays, using nuclear database input, explains all of the features seen in the Daya Bay evolution data. However, this summation method still allows for an anomaly. We conclude that there is currently not enough information to use the antineutrino flux changes to rule out the possible existence of sterile neutrinos.

  4. Precision Search for Muon Antineutrino Disappearance Oscillations Using a Dual Baseline Technique

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Gary Li [Columbia Univ., New York, NY (United States)

    2013-01-01

    A search for short baseline muon antineutrino disappearance with the SciBooNE and MiniBooNE experiments at Fermi National Accelerator Laboratory in Batavia, Illinois is presented. Short baseline muon antineutrino disappearance measurements help constrain sterile neutrino models. The two detectors observe muon antineutrinos from the same beam, therefore the combined analysis of their data sets serves to partially constrain some of the flux and cross section uncertainties. A likelihood ratio method was used to set a 90% confidence level upper limit on muon antineutrino disappearance that dramatically improves upon prior sterile neutrino oscillation limits in the Δm2=0.1-100 eV2 region.

  5. Opportunities for applied measurements using the PROSPECT antineutrino detector: reactor physics and safeguards

    Science.gov (United States)

    Bowden, Nathaniel; Prospect Collaboration

    2015-10-01

    Disagreement of reactor antineutrino spectrum and flux measurements with updated predictions indicates that we have much to learn about the complicated processes underlying antineutrino production in reactors, as well as hinting at new physics. A number of new efforts seek to address these questions, including the PROSPECT experiment planned at the HFIR research reactor. In addition to greatly advancing our understanding of reactor antineutrino emissions, PROSPECT can support a rich applied physics program. The detection technology developed for PROSPECT will enable precision antineutrino spectrum measurements close to essentially any reactor type. Here we describe how such measurements provide opportunities to probe fissile isotope and fission daughter distributions, and their potential use for reactor physics and safeguards applications. LLNL-ABS-673983. Prepared by LLNL under Contract DE-AC52-07NA27344.

  6. Extension of a Kinetic-Theory Approach for Computing Chemical-Reaction Rates to Reactions with Charged Particles

    Science.gov (United States)

    Liechty, Derek S.; Lewis, Mark J.

    2010-01-01

    Recently introduced molecular-level chemistry models that predict equilibrium and nonequilibrium reaction rates using only kinetic theory and fundamental molecular properties (i.e., no macroscopic reaction rate information) are extended to include reactions involving charged particles and electronic energy levels. The proposed extensions include ionization reactions, exothermic associative ionization reactions, endothermic and exothermic charge exchange reactions, and other exchange reactions involving ionized species. The extensions are shown to agree favorably with the measured Arrhenius rates for near-equilibrium conditions.

  7. Space and time resolved measurements of ion temperature with the CVI 5292 A charge exchange recombination line after subtracting background radiation

    International Nuclear Information System (INIS)

    Ida, K.; Hidekuma, S.

    1988-08-01

    An ion temperature profile has been obtained with the CVI 5292 A (n = 8 - 7) charge exchange recombination (CXR) line using a space and wave-length resolving visible spectrometer installed on the JIPP TII-U tokamak. Two sets of 50 channels optical fiber arrays: one viewing a fast neutral hydrogen beam (CXR channels) and the other viewing off the neutral beam line (background channels), is arranged on the entrance slit of the spectrometer. This spectrometer is coupled to an image intensifier and CCD detector at the focal plane and provides temperature profile every 1/60 second. An ion temperature is derived from the Doppler broadened line profile after subtracting the simultaneously measured cold component (background channels), which is due to electron-excitation and/or charge exchange recombination in the plasma periphery. Alternative approach to obtain the ion temperature profile without CXR is also demonstrated. This method is based on an Abel inversion technique for each wavelength separately. (author)

  8. Chandra Observations of a Collisionally and Optically Thin Charge Exchange System - Comet 2P/Encke 2003

    Science.gov (United States)

    Christian, D. J.; Lisse, C. M.; Dennerl, K.; Wolk, S. J.; Bodewits, D.; Combi, M. R.; Hoekstra, R.; Makinen, J. T. T.; Weaver, H. A.

    2004-11-01

    The highly favorable perigee passage of the x-ray bright comet 2P/Encke in late 2003 provided an excellent opportunity to use Chandra's high spatial, spectral, and temporal resolution to study cometary x-ray emission in the low neutral target density, low x-ray flux regime. The 1997 ROSAT/EUVE observations of Encke (Lisse et al. 1999) and the nucleus rotation studies of Luu and Jewitt (1990, most likely rotation period = 15 hours) suggested a simple Chandra experiment - continuous ACIS-S observations of Encke over 15 hours during the time of its closest approach to Earth. Here we report initial results from our X-ray observations. X-ray emission from comet Encke was found only in a small, asymmetric region between 1500 km - 40,000 km from the nucleus. The Encke ACIS-S3 200 -- 1000 eV spectrum shows many of the same x-ray emission lines previously observed from comets (C+5, O+6,O+7), including confirmation of several emission lines in the 800 to 1000 eV range. However, the Encke spectrum shows very different line ratios in the 200 - 700 eV range than any previous comet. A lightcurve with peak-to-peak amplitude of 20% and period 11.7 hours was found over the 15 hour observing period. Comparing the observations to contemporaneous measurements of the coma and solar wind made by other means, we find the combination of a low density, collisionally thin (to charge exchange) coma and a post-massive X-flare, high temperature, moderate density solar wind can explain our unusual Encke x-ray observations.

  9. Review of Langmuir-Wave-Caused Dips and Charge-Exchange-Caused Dips in Spectral Lines from Plasmas and their Applications

    Directory of Open Access Journals (Sweden)

    Elisabeth Dalimier

    2014-05-01

    Full Text Available We review studies of two kinds of dips in spectral line profiles emitted by plasmas—dips that have been predicted theoretically and observed experimentally: Langmuir-wave-caused dips (L-dips and charge-exchange-caused dips (X-dips. There is a principal difference with respect to positions of L-dips and X-dips relative to the unperturbed wavelength of a spectral line: positions of L-dips scale with the electron density Ne roughly as Ne1/2, while positions of X-dips are almost independent of Ne (the dependence is much weaker than for L-dips. L-dips and X-dips phenomena are important, both fundamentally and practically. The fundamental importance is due to a rich physics behind each of these phenomena. L-dips are a multi-frequency resonance phenomenon caused by a single-frequency (monochromatic electric field. X-dips are due to charge exchange at anticrossings of terms of a diatomic quasi-molecule, whose nuclei have different charges. As for important practical applications, they are as follows: observations of L-dips constitute a very accurate method to measure the electron density in plasmas—a method that does not require knowledge of the electron temperature. L-dips also allow measuring the amplitude of the electric field of Langmuir waves—the only spectroscopic method available for this purpose. Observations of X-dips provide an opportunity to determine rate coefficient of charge exchange between multi-charged ions. This is an important reference data, virtually inaccessible by other experimental methods. The rate coefficients of charge exchange are important for magnetic fusion in Tokamaks, for population inversion in the soft x-ray and VUV ranges, for ion storage devices, as well as for astrophysics (e.g., for the solar plasma and for determining the physical state of planetary nebulae.

  10. Spin isovector giant resonances in (n,p) reactions

    Energy Technology Data Exchange (ETDEWEB)

    Spicer, B.M.

    1997-12-31

    The present status of the study of spin-flip isovector giant resonances, using the (n,p) charge exchange reaction, is reviewed. After a brief history of the discovery of these giant resonances, a critical appraisal of the interpretation of the data in terms of giant resonances is given, along with some of the theoretical advances that impact on the interpretation of these data. A sampling of the results obtained for typical targets is given, followed by the interpretation of these results. A brief statement is made concerning the way forward in experimental technique for nuclear structure research using charge exchange reactions. 54 refs., 18 figs.

  11. Spin isovector giant resonances in (n,p) reactions

    International Nuclear Information System (INIS)

    Spicer, B.M.

    1997-01-01

    The present status of the study of spin-flip isovector giant resonances, using the (n,p) charge exchange reaction, is reviewed. After a brief history of the discovery of these giant resonances, a critical appraisal of the interpretation of the data in terms of giant resonances is given, along with some of the theoretical advances that impact on the interpretation of these data. A sampling of the results obtained for typical targets is given, followed by the interpretation of these results. A brief statement is made concerning the way forward in experimental technique for nuclear structure research using charge exchange reactions

  12. Measurement of charm production in antineutrino charged-current interactions

    CERN Document Server

    Onengüt, G; De Jong, M; Konijn, J; Melzer, O; Oldeman, R G C; Pesen, E; Van der Poel, C A F J; Visschers, J L; Güler, M; Köse, U; Serin-Zeyrek, M; Kama, S; Sever, R; Tolun, P; Zeyrek, M T; Catanesi, M G; De Serio, M; Ieva, M; Muciaccia, M T; Radicioni, E; Simone, S; Bülte, A; Winter, Klaus; Van de Vyver, B; Vilain, P; Wilquet, G; Saitta, B; Di Capua, E; Ogawa, S; Shibuya, H; Artamonov, A V; Brunner, J; Chizhov, M; Cussans, D G; Doucet, M; Fabre, Jean-Paul; Hristova, I R; Kawamura, T; Kolev, D; Litmaath, M; Meinhard, H; Panman, J; Papadopoulos, I M; Ricciardi, S; Rozanov, A; Saltzberg, D; Tsenov, R V; Uiterwijk, J W E; Zucchelli, P; Goldberg, J; Chikawa, M; Arik, E; Song, J S; Yoon, C S; Kodama, K; Ushida, N; Aoki, S; Hara, T; Delbar, T; Favart, D; Grégoire, G; Kalinin, S; Makhlyoueva, I V; Gorbunov, P; Khovanskii, V D; Shamanov, V V; Tsukerman, I; Bruski, N; Frekers, D; Rondeshagen, D; Wolff, T; Hoshino, K; Kawada, J; Komatsu, M; Miyanishi, M; Nakamura, M; Nakano, T; Narita, K; Niu, K; Niwa, K; Nonaka, N; Sato, O; Toshito, T; Buontempo, S; Cocco, A G; D'Ambrosio, N; De Lellis, G; De Rosa, G; Di Capua, F; Ereditato, A; Fiorillo, G; Marotta, A; Messina, M; Migliozzi, P; Pistillo, C; Santorelli, R; Scotto-Lavina, L; Strolin, P; Tioukov, V; Nakamura, K; Okusawa, T; Dore, U; FLoverre, P; Ludovici, L; Maslennikov, A L; Righini, P; Rosa, G; Santacesaria, R; Satta, A; Spada, F R; Barbuto, E; Bozza, C; Grella, G; Romano, G; Sirignano, C; Sorrentino, S; Sato, Y; Tezuka, I

    2004-01-01

    During the years 1994-97, the emulsion target of the CHORUS detector was exposed to the wideband neutrino beam of the CERN SPS collecting about 10^6 neutrino interactions. A measurement of nubar_mu-induced charm production is performed by usingthe presence of a 5% nubarmu component in the nu_mu beam. The measurement takes advantage of the capability to observe the decay topology in the emulsion. The analysis is based on a sample of charged-current interactions with at least one identified muon. About 100 000 vere located in the emulsion target and fully reconstructed. By requiring a positive muon charge as determined by the CHORUS spectrometer, 32-nubar_mu induced charm events were observed with an estimated background of 3.2 events. At an average antineutrino energy in the neutrino beam of 18GeV, the charm production rate induced by anitneutrinos is measured to be sigma(nubar_muN -> mu+cbarX)/sigma(nubar_muN -> mu+X) = (5.0^+1.4_-0.9(stat) +- 0.7(syst))%. The ratio between neutral and charged charm productio...

  13. Gadolinium-loaded gel scintillators for neutron and antineutrino detection

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Catherine Lynn; Akers, Douglas William; Demmer, Ricky Lynn; Paviet, Patricia Denise; Drigert, Mark William

    2016-11-29

    A gadolinium (Gd) loaded scintillation gel (Gd-ScintGel) compound allows for neutron and gamma-ray detection. The unique gel scintillator encompasses some of the best features of both liquid and solid scintillators, yet without many of the disadvantages associated therewith. Preferably, the gel scintillator is a water soluble Gd-DTPA compound and water soluble fluorophores such as: CdSe/ZnS (or ZnS) quantum dot (Q-dot) nanoparticles, coumarin derivatives 7-hydroxy-4-methylcoumarin, 7-hydroxy-4-methylcoumarin-3-acetic acid, 7-hydroxycoumarin-3-carboxylic acid, and Alexa Fluor 350 as well as a carbostyril compound, carbostyril 124 in a stable water-based gel, such as methylcellulose or polyacrylamide polymers. The Gd-loaded ScintGel allows for a homogenious distribution of the Gd-DTPA and the fluorophores, and yields clean fluorescent emission peaks. A moderator, such as deuterium or a water-based clear polymer, can be incorporated in the Gd-ScintGel. The gel scintillators can be used in compact detectors, including neutron and antineutrino detectors.

  14. Reactors as a Source of Antineutrinos: Effects of Fuel Loading and Burnup for Mixed-Oxide Fuels

    Science.gov (United States)

    Bernstein, Adam; Bowden, Nathaniel S.; Erickson, Anna S.

    2018-01-01

    In a conventional light-water reactor loaded with a range of uranium and plutonium-based fuel mixtures, the variation in antineutrino production over the cycle reflects both the initial core fissile inventory and its evolution. Under an assumption of constant thermal power, we calculate the rate at which antineutrinos are emitted from variously fueled cores, and the evolution of that rate as measured by a representative ton-scale antineutrino detector. We find that antineutrino flux decreases with burnup for low-enriched uranium cores, increases for full mixed-oxide (MOX) cores, and does not appreciably change for cores with a MOX fraction of approximately 75%. Accounting for uncertainties in the fission yields in the emitted antineutrino spectra and the detector response function, we show that the difference in corewide MOX fractions at least as small as 8% can be distinguished using a hypothesis test. The test compares the evolution of the antineutrino rate relative to an initial value over part or all of the cycle. The use of relative rates reduces the sensitivity of the test to an independent thermal power measurement, making the result more robust against possible countermeasures. This rate-only approach also offers the potential advantage of reducing the cost and complexity of the antineutrino detectors used to verify the diversion, compared to methods that depend on the use of the antineutrino spectrum. A possible application is the verification of the disposition of surplus plutonium in nuclear reactors.

  15. An assessment of anti-neutrino mass determination via electrostatic measurements of tritium beta-decay

    International Nuclear Information System (INIS)

    Le Bas, P.A.

    1984-01-01

    Data on the mass of the anti-neutrino determined via electrostatic measurements of tritium beta-decay are assessed. Relativistic calculations concerning the finite mass of the electron anti-neutrino and the recoil of the nucleus, are given for the theoretical end-point spectrum of tritium beta-decay. The specifications are given for an electrostatic Spherical Retarding Beta-Spectrometer, and an electrostatic Cylindrical Mirror Analyser, both used in the tritium beta-decay experiment. The electrostatic measurements lead to a value of less than 50 ev (90% C.L.) for the electron anti-neutrino mass. These results are discussed in terms of the resolution of the electrostatic equipment and the Monte Carlo simulations of the data collection. (UK)

  16. Design of a Fast Neutral He Beam System for Feasibility Study of Charge-Exchange Alpha-Particle Diagnostics in a Thermonuclear Fusion Reactor

    CERN Document Server

    Shinto, Katsuhiro; Kitajima, Sumio; Kiyama, Satoru; Nishiura, Masaki; Sasao, Mamiko; Sugawara, Hiroshi; Takenaga, Mahoko; Takeuchi, Shu; Wada, Motoi

    2005-01-01

    For alpha-particle diagnostics in a thermonuclear fusion reactor, neutralization using a fast (~2 MeV) neutral He beam produced by the spontaneous electron detachment of a He- is considered most promising. However, the beam transport of produced fast neutral He has not been studied, because of difficulty for producing high-brightness He- beam. Double-charge-exchange He- sources and simple beam transport systems were developed and their results were reported in the PAC99* and other papers.** To accelerate an intense He- beam and verify the production of the fast neutral He beam, a new test stand has been designed. It consists of a multi-cusp He+

  17. DXL: A Sounding Rocket Mission for the Study of Solar Wind Charge Exchange and Local Hot Bubble X-Ray Emission

    Science.gov (United States)

    Galeazzi, M.; Prasai, K.; Uprety, Y.; Chiao, M.; Collier, M. R.; Koutroumpa, D.; Porter, F. S.; Snowden, S.; Cravens, T.; Robertson, I.; hide

    2011-01-01

    The Diffuse X-rays from the Local galaxy (DXL) mission is an approved sounding rocket project with a first launch scheduled around December 2012. Its goal is to identify and separate the X-ray emission generated by solar wind charge exchange from that of the local hot bubble to improve our understanding of both. With 1,000 square centimeters proportional counters and grasp of about 10 square centimeters sr both in the 1/4 and 3/4 keV bands, DXL will achieve in a 5-minute flight what cannot be achieved by current and future X-ray satellites.

  18. Measurement of Anomalously Strong Emission from the 1s-9p Transition in the Spectrum of H-like Phosphorus Following Charge Exchange with Molecular Hydrogen

    Science.gov (United States)

    Leutenegger, M. A.; Beiersdorfer, P.; Brown, G. V.; Kelley, R. L.; Porter, F. S.

    2010-01-01

    We have measured K-shell x-ray spectra of highly ionized argon and phosphorus following charge exchange with molecular hydrogen at low collision energy in an electron beam ion trap using an x-ray calorimeter array with approx.6 eV resolution. We find that the emission at the high-end of the Lyman series is greater by a factor of two for phosphorus than for argon, even though the measurement was performed concurrently and the atomic numbers are similar. This does not agree with current theoretical models and deviates from the trend observed in previous measurements.

  19. Search for Lorentz invariance and CPT violation with muon antineutrinos in the MINOS Near Detector

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, P. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); et al.

    2012-02-01

    We have searched for sidereal variations in the rate of antineutrino interactions in the MINOS Near Detector. Using antineutrinos produced by the NuMI beam, we find no statistically significant sidereal modulation in the rate. When this result is placed in the context of the Standard Model Extension theory we are able to place upper limits on the coefficients defining the theory. These limits are used in combination with the results from an earlier analysis of MINOS neutrino data to further constrain the coefficients.

  20. Two particle–hole excitations in charged current quasielastic antineutrino-nucleus scattering

    International Nuclear Information System (INIS)

    Nieves, J.; Ruiz Simo, I.; Vicente Vacas, M.J.

    2013-01-01

    We evaluate the quasielastic and multinucleon contributions to the antineutrino-nucleus scattering cross section and compare our results with the recent MiniBooNE data. We use a local Fermi gas model that includes RPA correlations and gets the multinucleon part from a systematic many body expansion of the W boson selfenergy in the nuclear medium. The same model had been quite successful for the neutrino cross section and contains no new parameters. We have also analyzed the relevance of 2p2h events for the antineutrino energy reconstruction

  1. First test of Lorentz violation with a reactor-based antineutrino experiment

    International Nuclear Information System (INIS)

    Abe, Y.; Ishitsuka, M.; Konno, T.; Kuze, M.; Aberle, C.; Buck, C.; Hartmann, F.X.; Haser, J.; Kaether, F.; Lindner, M.; Reinhold, B.; Schwetz, T.; Wagner, S.; Watanabe, H.; Anjos, J.C. dos; Gama, R.; Lima, H.P.-Jr.; Pepe, I.M.; Bergevin, M.; Felde, J.; Maesano, C.N.; Bernstein, A.; Bowden, N.S.; Dazeley, S.; Erickson, A.; Keefer, G.; Bezerra, T.J.C.; Furuta, H.; Suekane, F.; Bezrukhov, L.; Lubsandorzhiev, B.K.; Yanovitch, E.; Blucher, E.; Conover, E.; Crum, K.; Strait, M.; Worcester, M.; Busenitz, J.; Goon, J.TM.; Habib, S.; Ostrovskiy, I.; Reichenbacher, J.; Stancu, I.; Sun, Y.; Cabrera, A.; Franco, D.; Kryn, D.; Obolensky, M.; Roncin, R.; Tonazzo, A.; Caden, E.; Damon, E.; Lane, C.E.; Maricic, J.; Miletic, T.; Milincic, R.; Perasso, S.; Smith, E.; Camilleri, L.; Carr, R.; Franke, A.J.; Shaevitz, M.H.; Toups, M.; Cerrada, M.; Crespo-Anadon, J.I.; Gil-Botella, I.; Lopez-Castano, J.M.; Novella, P.; Palomares, C.; Santorelli, R.; Chang, P.J.; Horton-Smith, G.A.; McKee, D.; Shrestha, D.; Chimenti, P.; Classen, T.; Collin, A.P.; Cucoanes, A.; Durand, V.; Fechner, M.; Fischer, V.; Hayakawa, T.; Lasserre, T.; Letourneau, A.; Lhuillier, D.; Mention, G.; Mueller, Th.A.; Perrin, P.; Sida, J.L.; Sinev, V.; Veyssiere, C.

    2012-01-01

    We present a search for Lorentz violation with 8249 candidate electron antineutrino events taken by the Double Chooz experiment in 227.9 live days of running. This analysis, featuring a search for a sidereal time dependence of the events, is the first test of Lorentz invariance using a reactor-based antineutrino source. No sidereal variation is present in the data and the disappearance results are consistent with sidereal time independent oscillations. Under the Standard-Model Extension, we set the first limits on 14 Lorentz violating coefficients associated with transitions between electron and tau flavor, and set two competitive limits associated with transitions between electron and muon flavor. (authors)

  2. Monte Carlo Simulation of a Segmented Detector for Low-Energy Electron Antineutrinos

    Science.gov (United States)

    Qomi, H. Akhtari; Safari, M. J.; Davani, F. Abbasi

    2017-11-01

    Detection of low-energy electron antineutrinos is of importance for several purposes, such as ex-vessel reactor monitoring, neutrino oscillation studies, etc. The inverse beta decay (IBD) is the interaction that is responsible for detection mechanism in (organic) plastic scintillation detectors. Here, a detailed study will be presented dealing with the radiation and optical transport simulation of a typical segmented antineutrino detector withMonte Carlo method using MCNPX and FLUKA codes. This study shows different aspects of the detector, benefiting from inherent capabilities of the Monte Carlo simulation codes.

  3. Cross sections for multistep direct reactions

    International Nuclear Information System (INIS)

    Demetriou, Paraskevi; Marcinkowski, Andrzej; Marianski, Bohdan

    2002-01-01

    Inelastic scattering and charge-exchange reactions have been analysed at energies ranging from 14 to 27 MeV using the modified multistep direct reaction theory (MSD) of Feshbach, Kerman and Koonin. The modified theory considers the non-DWBA matrix elements in the MSD cross section formulae and includes both incoherent particle-hole excitations and coherent collective excitations in the continuum, according to the prescriptions. The results show important contributions from multistep processes at all energies considered. (author)

  4. Total Absorption Spectroscopy of Fission Fragments Relevant for Reactor Antineutrino Spectra and Decay Heat Calculations

    Directory of Open Access Journals (Sweden)

    Porta A.

    2016-01-01

    Full Text Available Beta decay of fission products is at the origin of decay heat and antineutrino emission in nuclear reactors. Decay heat represents about 7% of the reactor power during operation and strongly impacts reactor safety. Reactor antineutrino detection is used in several fundamental neutrino physics experiments and it can also be used for reactor monitoring and non-proliferation purposes. 92,93Rb are two fission products of importance in reactor antineutrino spectra and decay heat, but their β-decay properties are not well known. New measurements of 92,93Rb β-decay properties have been performed at the IGISOL facility (Jyväskylä, Finland using Total Absorption Spectroscopy (TAS. TAS is complementary to techniques based on Germanium detectors. It implies the use of a calorimeter to measure the total gamma intensity de-exciting each level in the daughter nucleus providing a direct measurement of the beta feeding. In these proceedings we present preliminary results for 93Rb, our measured beta feedings for 92Rb and we show the impact of these results on reactor antineutrino spectra and decay heat calculations.

  5. Sterile neutrinos or flux uncertainties? — Status of the reactor anti-neutrino anomaly

    Science.gov (United States)

    Dentler, Mona; Hernández-Cabezudo, Álvaro; Kopp, Joachim; Maltoni, Michele; Schwetz, Thomas

    2017-11-01

    The ˜ 3 σ discrepancy between the predicted and observed reactor anti-neutrino flux, known as the reactor anti-neutrino anomaly, continues to intrigue. The recent discovery of an unexpected bump in the reactor anti-neutrino spectrum, as well as indications that the flux deficit is different for different fission isotopes seems to disfavour the explanation of the anomaly in terms of sterile neutrino oscillations. We critically review this conclusion in view of all available data on electron (anti)neutrino disappearance. We find that the sterile neutrino hypothesis cannot be rejected based on global data and is only mildly disfavored compared to an individual rescaling of neutrino fluxes from different fission isotopes. The main reason for this is the presence of spectral features in recent data from the NEOS and DANSS experiments. If state-of-the-art predictions for reactor fluxes are taken at face value, sterile neutrino oscillations allow a consistent description of global data with a significance close to 3 σ relative to the no-oscillation case. Even if reactor fluxes and spectra are left free in the fit, a 2 σ hint in favour of sterile neutrinos remains, with allowed parameter regions consistent with an explanation of the anomaly in terms of oscillations.

  6. Neutrino and antineutrino inclusive charged-current cross section measurement with the MINOS near detector

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Debdatta [Univ. of Pittsburgh, PA (United States)

    2009-01-01

    This thesis presents the measurement of energy dependence of the neutrino-nucleon inclusive charged current cross section on an isoscalar target in the range 3-50 GeV for neutrinos and 5-50 GeV energy range for antineutrinos. The data set was collected with the MINOS Near Detector using the wide band NuMI beam at Fermilab. The size of the charged current sample is 1.94 x 106 neutrino events and 1.60 x 105 antineutrino events. The flux has been extracted using a low hadronic energy sub-sample of the charged current events. The energy dependence of the cross section is obtained by dividing the charged current sample with the extracted flux. The neutrino and antineutrino cross section exhibits a linear dependence on energy at high energy but shows deviations from linear behavior at low energy. We also present a measurement of the ratio of antineutrino to neutrino inclusive cross section.

  7. New Decay Data Sub-library for Calculation of Nuclear Reactors Antineutrino Spectra

    Science.gov (United States)

    Sonzogni, Alejandro; McCutchan, Elizabeth; Johnson, Timothy

    2015-10-01

    The ENDF/B-VII.1 decay data sub-library contains up-to-date decay properties for all known nuclides and can be used in a wide variety of applications such as decay heat, delayed nu-bar and astrophysics. We have recently completed an upgrade to the ENDF/B-VII.1 decay data sub-library in order to better calculate antineutrino spectra from fission of actinide nuclides. This sub-library has been used to identify the main contributors to the antineutrino spectra as well as to derive a systematic behavior of the energy integrated spectra similar to that of the beta-delayed neutron multiplicities. The main improvements have been the use of the TAGS data from Algora et al and Greenwood et al, as well as some of the single beta spectrum data from Rudstam et al to obtain beta minus level feedings. Additionally, we have calculated the antineutrino spectra for neutron energies higher than thermal, needed for highly-enriched uranium cores, such as the HFIR in ORNL that will be used in the PROSPECT experiment. These calculations are relevant since the high precision beta spectra which are used in many antineutrino calculations were measured at thermal energies. The impact of the fission yield data on these calculations will be discussed. This work was sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886.

  8. Modelling of the anti-neutrino production and spectra from a Magnox reactor

    Science.gov (United States)

    Mills, Robert W.; Mountford, David J.; Coleman, Jonathon P.; Metelko, Carl; Murdoch, Matthew; Schnellbach, Yan-Jie

    2018-01-01

    The anti-neutrino source properties of a fission reactor are governed by the production and beta decay of the radionuclides present and the summation of their individual anti-neutrino spectra. The fission product radionuclide production changes during reactor operation and different fissioning species give rise to different product distributions. It is thus possible to determine some details of reactor operation, such as power, from the anti-neutrino emission to confirm safeguards records. Also according to some published calculations, it may be feasible to observe different anti-neutrino spectra depending on the fissile contents of the reactor fuel and thus determine the reactor's fissile material inventory during operation which could considerable improve safeguards. In mid-2014 the University of Liverpool deployed a prototype anti-neutrino detector at the Wylfa R1 station in Anglesey, United Kingdom based upon plastic scintillator technology developed for the T2K project. The deployment was used to develop the detector electronics and software until the reactor was finally shutdown in December 2015. To support the development of this detector technology for reactor monitoring and to understand its capabilities, the National Nuclear Laboratory modelled this graphite moderated and natural uranium fuelled reactor with existing codes used to support Magnox reactor operations and waste management. The 3D multi-physics code PANTHER was used to determine the individual powers of each fuel element (8×6152) during the year and a half period of monitoring based upon reactor records. The WIMS/TRAIL/FISPIN code route was then used to determine the radionuclide inventory of each nuclide on a daily basis in each element. These nuclide inventories were then used with the BTSPEC code to determine the anti-neutrino spectra and source strength using JEFF-3.1.1 data. Finally the anti-neutrino source from the reactor for each day during the year and a half of monitored reactor

  9. Modelling of the anti-neutrino production and spectra from a Magnox reactor

    Directory of Open Access Journals (Sweden)

    Mills Robert W

    2018-01-01

    Full Text Available The anti-neutrino source properties of a fission reactor are governed by the production and beta decay of the radionuclides present and the summation of their individual anti-neutrino spectra. The fission product radionuclide production changes during reactor operation and different fissioning species give rise to different product distributions. It is thus possible to determine some details of reactor operation, such as power, from the anti-neutrino emission to confirm safeguards records. Also according to some published calculations, it may be feasible to observe different anti-neutrino spectra depending on the fissile contents of the reactor fuel and thus determine the reactor's fissile material inventory during operation which could considerable improve safeguards. In mid-2014 the University of Liverpool deployed a prototype anti-neutrino detector at the Wylfa R1 station in Anglesey, United Kingdom based upon plastic scintillator technology developed for the T2K project. The deployment was used to develop the detector electronics and software until the reactor was finally shutdown in December 2015. To support the development of this detector technology for reactor monitoring and to understand its capabilities, the National Nuclear Laboratory modelled this graphite moderated and natural uranium fuelled reactor with existing codes used to support Magnox reactor operations and waste management. The 3D multi-physics code PANTHER was used to determine the individual powers of each fuel element (8×6152 during the year and a half period of monitoring based upon reactor records. The WIMS/TRAIL/FISPIN code route was then used to determine the radionuclide inventory of each nuclide on a daily basis in each element. These nuclide inventories were then used with the BTSPEC code to determine the anti-neutrino spectra and source strength using JEFF-3.1.1 data. Finally the anti-neutrino source from the reactor for each day during the year and a half of

  10. The relevance of the vertex bremsstrahlung photon detection in the electron-neutrino (antineutrino) electron scattering experiments at low energy

    CERN Document Server

    Broggini, C; Moretti, M

    1999-01-01

    We discuss the size of the electron-antineutrino electron into electron-antineutrino electron cross section reduction due to the rejection of the events with a vertex bremsstrahlung photon above a certain energy in the final state. In particular we analyze the effect in experiments designed to detect the low energy electron-antineutrino and electron-neutrino from a nuclear reactor and from the Sun. We find that such reduction has to be considered in a relatively high statistic reactor experiment, while it is negligible for pp and 7Be solar neutrino detection.

  11. First Measurement of the Muon Anti-Neutrino Charged Current Quasielastic Double-Differential Cross-Section

    Energy Technology Data Exchange (ETDEWEB)

    Grange, Joseph M. [Univ. of Florida, Gainesville, FL (United States)

    2013-01-01

    This dissertation presents the first measurement of the muon antineutrino charged current quasi-elastic double-differential cross section. These data significantly extend the knowledge of neutrino and antineutrino interactions in the GeV range, a region that has recently come under scrutiny due to a number of conflicting experimental results. To maximize the precision of this measurement, three novel techniques were employed to measure the neutrino background component of the data set. Representing the first measurements of the neutrino contribution to an accelerator-based antineutrino beam in the absence of a magnetic field, the successful execution of these techniques carry implications for current and future neutrino experiments.

  12. Coherent pion production in the 12C and 40Ca by the (3 He,tπ+) charge exchange reaction at 2 GeV

    International Nuclear Information System (INIS)

    Farhi, Laurent

    1997-01-01

    The coherent pion production process on nuclei is defined as the excitation of the first excited state of the nucleon, the delta(1232) resonance, creating a delta-hole state. This state propagates through the nuclear medium and then decays in a single pion, living the target nuclei in its ground state. In the nuclei, the attractive interaction between delta-hole states in the spin-longitudinal channel shifts down the effective mass of the delta and induces a collective state of excitation. The nuclear response in the longitudinal channel of interaction can be studied experimentally through the resonance decay coherent process triggered by a probe coupling longitudinally with the delta and selected by the target form factor. The ( 3 He, t) probe at 2 GeV on nuclei and the experimental set-up SPES IV-Pi have been used to study this decay process. A simulation program using GEANT and including theoretical consideration, knowledge of previous experimental results and the experimental properties of the set-up, have demonstrated the capability of the experiment for this study. The setting of the PCOS-IV acquisition system of multiwire proportional chambers and of the development and use of programs for treatment and analysis of experimental data have been necessary steps to make the experiment at Laboratoire National SATURNE as well as to obtain physical parameters in order to exhibit the coherent process. Nevertheless, the angular distribution of coherent pions differ from the theoretical predictions. Several hypotheses involving the experimental set-up and physical processes have been investigated in order to account for such distributions. (author)

  13. Precise measurement of neutrino and anti-neutrino differential cross sections on iron

    Energy Technology Data Exchange (ETDEWEB)

    Tzanov, Martin Mihaylov [Pittsburgh U.

    2005-11-01

    This thesis will present a precise measurement of the differential cross section for charged current neutrino and anti-neutrino scattering from iron. The NuTeV experiment took data during 1996-97 and collected 8.6 10 º and 2.4 10 º charged-current (CC) interactions. The experiment combines sign-selected neutrino and antineutrino beams and the upgraded CCFR iron-scintillator neutrino detector. A precision continuous calibration beam was used to determine the muon and hadron energy scales to a precision of about a factor of two better than previous experiments. The structure functions F (x,Q2) and xF3(x,Q2) are extracted and compared with theory and previous measurements.

  14. Study for Reactor Monitoring using Anti-neutrino Detection in the Neos experiment

    Energy Technology Data Exchange (ETDEWEB)

    Han, Bo Young; Sun, Gwang Min [KAERI, Daejeon (Korea, Republic of); Jeon, Eun Ju [ISB, Daejeon (Korea, Republic of); and others

    2016-05-15

    In this study we describe a feasibility study of reactor monitoring using antineutrino detection in the Neutrino Experiment for Oscillation at Short baseline (NEOS) at Hanbit power plant. Recently, in the perspective of nonproliferation issues and misuse of nuclear energy as a fast-growing nuclear energy industry, the application of anti-neutrino measurement has been proposed and the feasibility studies has been carried out as a novel technology for monitoring the burning process of nuclear power reactor. The NEOS detector with 1000 L Gd-doped liquid scintillator was installed in tendon gallery at Hanbit power station unit 5 and has been collecting close to 2000 IBD events per day with the signal to noise ratio of ∼ 20. As a preliminary result, we demonstrate the possibility of monitoring nuclear power reactor with the IBD counting rate during reactor power ON, ramping up, and OFF.

  15. Determination of the fission coefficients in thermal nuclear reactors for antineutrino detection

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Lenilson M. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Cabral, Ronaldo G., E-mail: rgcabral@ime.eb.b [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Anjos, Joao C.C. dos, E-mail: janjos@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Dept. GLN - G

    2011-07-01

    The nuclear reactors in operation periodically need to change their fuel. It is during this process that these reactors are more vulnerable to occurring of several situations of fuel diversion, thus the monitoring of the nuclear installations is indispensable to avoid events of this nature. Considering this fact, the most promissory technique to be used for the nuclear safeguard for the nonproliferation of nuclear weapons, it is based on the detection and spectroscopy of antineutrino from fissions that occur in the nuclear reactors. The detection and spectroscopy of antineutrino, they both depend on the single contribution for the total number of fission of each actinide in the core reactor, these contributions receive the name of fission coefficients. The goal of this research is to show the computational and mathematical modeling used to determinate these coefficients for PWR reactors. (author)

  16. Shifts of neutrino oscillation parameters in reactor antineutrino experiments with non-standard interactions

    Directory of Open Access Journals (Sweden)

    Yu-Feng Li

    2014-11-01

    Full Text Available We discuss reactor antineutrino oscillations with non-standard interactions (NSIs at the neutrino production and detection processes. The neutrino oscillation probability is calculated with a parametrization of the NSI parameters by splitting them into the averages and differences of the production and detection processes respectively. The average parts induce constant shifts of the neutrino mixing angles from their true values, and the difference parts can generate the energy (and baseline dependent corrections to the initial mass-squared differences. We stress that only the shifts of mass-squared differences are measurable in reactor antineutrino experiments. Taking Jiangmen Underground Neutrino Observatory (JUNO as an example, we analyze how NSIs influence the standard neutrino measurements and to what extent we can constrain the NSI parameters.

  17. A Comparison Framework for Reactor Anti-Neutrino Detectors in Near-Field Nuclear Safeguards Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mendenhall, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bowden, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brodsky, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-11-03

    Electron anti-neutrino ( e) detectors can support nuclear safeguards, from reactor monitoring to spent fuel characterization. In recent years, the scientific community has developed multiple detector concepts, many of which have been prototyped or deployed for specific measurements by their respective collaborations. However, the diversity of technical approaches, deployment conditions, and analysis techniques complicates direct performance comparison between designs. We have begun development of a simulation framework to compare and evaluate existing and proposed detector designs for nonproliferation applications in a uniform manner. This report demonstrates the intent and capabilities of the framework by evaluating four detector design concepts, calculating generic reactor antineutrino counting sensitivity, and capabilities in a plutonium disposition application example.

  18. First Measurement of one Pion Production in Charged Current Neutrino and Antineutrino events on Argon

    Energy Technology Data Exchange (ETDEWEB)

    Scanavini, Scanavini,Giacomo [Yale U.

    2017-01-01

    This thesis presents a work done in the context of the Fermilab Neutrino Intensity Frontier. In this analysis, the cross section of single charged pion production in charged-current neutrino and antineutrino interactions with the argon nucleus target are measured. These measurements are performed using the Argon Neutrino Test (ArgoNeuT) detector exposed to the Fermilab Neutrino From The Main Injector (NuMI) beam operating in the low energy antineutrino mode. The signal is a charged-current μ interaction in the detector, with exactly one charged pion exiting the target nucleus, with momentum above 100 MeV/c. There shouldn’t be any 0 or kaons in the final state. There is no restriction on other mesons or nucleons. Total and differential cross section measurements are presented. The results are reported in terms of outgoing muon angle and momentum, outgoing pion angle and angle between outgoing pion and muon. The total cross sections, averaged over the flux, are found to be 8.2 ± 0.9 (stat) +0.9 -1.1 (syst) × 10-38 cm2 per argon nuclei and 2.5 ± 0.4 (stat) ± 0.5 (syst) × 10-37 cm2 per argon nuclei for antineutrino and neutrino respectively at a mean neutrino energy of 3.6 GeV (antineutrinos) and 9.6 GeV (neutrinos). This is the first time the single pion production in charged-current interactions cross section is measured on argon nuclei.

  19. Lithium Gadolinium Borate in Plastic Scintillator as an Antineutrino Detection Material

    Science.gov (United States)

    2010-06-01

    commercial reactor stage is fuel assembly inventory accountancy, reactor operator declarations of power and burnup and auditing by the IAEA. Current...of the groups that first established the correlation between reactor antineutrino flux, thermal power, and fuel burnup has proposed a cubic meter...certainly all escape without depositing much energy. The expected ratio for Gd captures to Li or B is hard to calculate as it depends strongly on the

  20. Reactor neutron converter into antineutrinos on base of lithium compounds and their solutions

    International Nuclear Information System (INIS)

    Lyutostanskij, Yu.S.; Lyashchuk, V.I.

    1990-01-01

    A study on the possibility of using various lithium compounds as substances for reactor neutron converter into antineutrinos, was made. It is concluded that heavy water LiOD, LiODxD 2 O, LiD solutions are the most promising ones. They provide for high efficiency with reduction of the required lithium mass (300-350 times maximum) as compared with pure lithium converter

  1. How unequal fluxes of high energy astrophysical neutrinos and antineutrinos can fake new physics

    International Nuclear Information System (INIS)

    Nunokawa, Hiroshi; Panes, Boris; Funchal, Renata Zukanovich

    2016-01-01

    Flavor ratios of very high energy astrophysical neutrinos, which can be studied at the Earth by a neutrino telescope such as IceCube, can serve to diagnose their production mechanism at the astrophysical source. The flavor ratios for neutrinos and antineutrinos can be quite different as we do not know how they are produced in the astrophysical environment. Due to this uncertainty the neutrino and antineutrino flavor ratios at the Earth also could be quite different. Nonetheless, it is generally assumed that flavor ratios for neutrinos and antineutrinos are the same at the Earth, in fitting the high energy astrophysical neutrino data. This is a reasonable assumption for the limited statistics for the data we currently have. However, in the future the fit must be performed allowing for a possible discrepancy in these two fractions in order to be able to disentangle different production mechanisms at the source from new physics in the neutrino sector. To reinforce this issue, in this work we show that a wrong assumption about the distribution of neutrino flavor ratios at the Earth may indeed lead to misleading interpretations of IceCube results.

  2. How unequal fluxes of high energy astrophysical neutrinos and antineutrinos can fake new physics

    Energy Technology Data Exchange (ETDEWEB)

    Nunokawa, Hiroshi [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, C.P. 38071, 22452-970, Rio de Janeiro (Brazil); Panes, Boris; Funchal, Renata Zukanovich [Instituto de Física, Universidade de São Paulo, C.P. 66.318, 05315-970 São Paulo (Brazil)

    2016-10-21

    Flavor ratios of very high energy astrophysical neutrinos, which can be studied at the Earth by a neutrino telescope such as IceCube, can serve to diagnose their production mechanism at the astrophysical source. The flavor ratios for neutrinos and antineutrinos can be quite different as we do not know how they are produced in the astrophysical environment. Due to this uncertainty the neutrino and antineutrino flavor ratios at the Earth also could be quite different. Nonetheless, it is generally assumed that flavor ratios for neutrinos and antineutrinos are the same at the Earth, in fitting the high energy astrophysical neutrino data. This is a reasonable assumption for the limited statistics for the data we currently have. However, in the future the fit must be performed allowing for a possible discrepancy in these two fractions in order to be able to disentangle different production mechanisms at the source from new physics in the neutrino sector. To reinforce this issue, in this work we show that a wrong assumption about the distribution of neutrino flavor ratios at the Earth may indeed lead to misleading interpretations of IceCube results.

  3. Resonant antineutrino induced electron capture with low energy bound-beta beams

    Energy Technology Data Exchange (ETDEWEB)

    Oldeman, R.G.C.; Meloni, M.; Saitta, B. [Universita degli Studi di Cagliari (Italy); INFN, Sezione di Cagliari, Dipartimento di Fisica, Cagliari (Italy)

    2010-01-15

    Antineutrino induced electron capture is a resonant process that can have a large cross-section for beams of monochromatic antineutrinos. We calculate the cross-section of this process and investigate an experimental setup where monochromatic antineutrinos are produced from the bound-beta decay of fully ionized radioactive atoms in a storage ring. If the energy between the source and the target is well matched, the cross-sections can be significantly larger than the cross-sections of commonly used non-resonant processes. The rate that can be achieved at a small distance between the source and two targets of 10{sup 3} kg is up to one interaction per 8.3.10{sup 18} decaying atoms. For a source-target distance corresponding to the first atmospheric neutrino oscillation maximum, the largest rate is one interaction per 3.2.10{sup 21} decaying atoms, provided that extremely stringent monochromaticity conditions (10{sup -7} or better) are achieved in future ion beams. (orig.)

  4. Measurement of the electroweak coupling of neutrinos and antineutrinos on electrons

    International Nuclear Information System (INIS)

    Jonker, M.

    1983-01-01

    This thesis describes the analysis of the events induced by elastic scattering of neutrinos and antineutrinos on electrons and interprets the results in terms of the coupling strength of (anti)neutrino on electrons. The data for this analysis were obtained with the electronic calorimeter of the CHARM (Amsterdam, Cern, Hamburg, Moscow, Rome) collaboration during the wide band neutrino beam exposures of 1979, 1980 and 1981 in the neutrino facility of the SPS (Super Proton Synchrotron) at CERN (Conseil Europeen pour la Recherche Nucleaire, Geneva, Switzerland). In chapter 1 a historical overview of the early neutrino physics and a description of the phenomenological Lagrangian is given, followed by an introduction to the electroweak unification model. The neutrino detector of the CHARM collaboration is described in chapter 2. Chapter 3 deals with the on-line monitoring system of this detector which has been under the responsibility of the author. The wide band neutrino facility of the CERN SPS is described in chapter 4, followed by a discussion of the experimental method to measure the neutrino energy spectra of the neutrino beams. The electromagnetic shower development process is reviewed in chapter 5 and is followed by a description of the technique that was used to separate showers of electromagnetic and hadronic origin. Chapter 6 discusses the observed signal of the (anti)neutrinos scattering on electrons and interprets these events in terms of the parameters related to the strength of the coupling of neutrinos to electrons. (Auth.)

  5. Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay.

    Science.gov (United States)

    An, F P; Balantekin, A B; Band, H R; Bishai, M; Blyth, S; Cao, D; Cao, G F; Cao, J; Chan, Y L; Chang, J F; Chang, Y; Chen, H S; Chen, Q Y; Chen, S M; Chen, Y X; Chen, Y; Cheng, J; Cheng, Z K; Cherwinka, J J; Chu, M C; Chukanov, A; Cummings, J P; Ding, Y Y; Diwan, M V; Dolgareva, M; Dove, J; Dwyer, D A; Edwards, W R; Gill, R; Gonchar, M; Gong, G H; Gong, H; Grassi, M; Gu, W Q; Guo, L; Guo, X H; Guo, Y H; Guo, Z; Hackenburg, R W; Hans, S; He, M; Heeger, K M; Heng, Y K; Higuera, A; Hsiung, Y B; Hu, B Z; Hu, T; Huang, E C; Huang, H X; Huang, X T; Huang, Y B; Huber, P; Huo, W; Hussain, G; Jaffe, D E; Jen, K L; Ji, X P; Ji, X L; Jiao, J B; Johnson, R A; Jones, D; Kang, L; Kettell, S H; Khan, A; Kohn, S; Kramer, M; Kwan, K K; Kwok, M W; Langford, T J; Lau, K; Lebanowski, L; Lee, J; Lee, J H C; Lei, R T; Leitner, R; Leung, J K C; Li, C; Li, D J; Li, F; Li, G S; Li, Q J; Li, S; Li, S C; Li, W D; Li, X N; Li, X Q; Li, Y F; Li, Z B; Liang, H; Lin, C J; Lin, G L; Lin, S; Lin, S K; Lin, Y-C; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, J L; Liu, J C; Loh, C W; Lu, C; Lu, H Q; Lu, J S; Luk, K B; Ma, X Y; Ma, X B; Ma, Y Q; Malyshkin, Y; Martinez Caicedo, D A; McDonald, K T; McKeown, R D; Mitchell, I; Nakajima, Y; Napolitano, J; Naumov, D; Naumova, E; Ngai, H Y; Ochoa-Ricoux, J P; Olshevskiy, A; Pan, H-R; Park, J; Patton, S; Pec, V; Peng, J C; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Qiu, R M; Raper, N; Ren, J; Rosero, R; Roskovec, B; Ruan, X C; Steiner, H; Stoler, P; Sun, J L; Tang, W; Taychenachev, D; Treskov, K; Tsang, K V; Tull, C E; Viaux, N; Viren, B; Vorobel, V; Wang, C H; Wang, M; Wang, N Y; Wang, R G; Wang, W; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Wei, H Y; Wen, L J; Whisnant, K; White, C G; Whitehead, L; Wise, T; Wong, H L H; Wong, S C F; Worcester, E; Wu, C-H; Wu, Q; Wu, W J; Xia, D M; Xia, J K; Xing, Z Z; Xu, J L; Xu, Y; Xue, T; Yang, C G; Yang, H; Yang, L; Yang, M S; Yang, M T; Yang, Y Z; Ye, M; Ye, Z; Yeh, M; Young, B L; Yu, Z Y; Zeng, S; Zhan, L; Zhang, C; Zhang, C C; Zhang, H H; Zhang, J W; Zhang, Q M; Zhang, R; Zhang, X T; Zhang, Y M; Zhang, Y X; Zhang, Y M; Zhang, Z J; Zhang, Z Y; Zhang, Z P; Zhao, J; Zhou, L; Zhuang, H L; Zou, J H

    2017-06-23

    The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW_{th} reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective ^{239}Pu fission fractions F_{239} from 0.25 to 0.35, Daya Bay measures an average IBD yield σ[over ¯]_{f} of (5.90±0.13)×10^{-43}  cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×10^{-43}  cm^{2}/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the ^{239}Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1σ. This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes ^{235}U, ^{239}Pu, ^{238}U, and ^{241}Pu. Based on measured IBD yield variations, yields of (6.17±0.17) and (4.27±0.26)×10^{-43}  cm^{2}/fission have been determined for the two dominant fission parent isotopes ^{235}U and ^{239}Pu. A 7.8% discrepancy between the observed and predicted ^{235}U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.

  6. Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

    Science.gov (United States)

    An, F. P.; Balantekin, A. B.; Band, H. R.; Bishai, M.; Blyth, S.; Cao, D.; Cao, G. F.; Cao, J.; Chan, Y. L.; Chang, J. F.; Chang, Y.; Chen, H. S.; Chen, Q. Y.; Chen, S. M.; Chen, Y. X.; Chen, Y.; Cheng, J.; Cheng, Z. K.; Cherwinka, J. J.; Chu, M. C.; Chukanov, A.; Cummings, J. P.; Ding, Y. Y.; Diwan, M. V.; Dolgareva, M.; Dove, J.; Dwyer, D. A.; Edwards, W. R.; Gill, R.; Gonchar, M.; Gong, G. H.; Gong, H.; Grassi, M.; Gu, W. Q.; Guo, L.; Guo, X. H.; Guo, Y. H.; Guo, Z.; Hackenburg, R. W.; Hans, S.; He, M.; Heeger, K. M.; Heng, Y. K.; Higuera, A.; Hsiung, Y. B.; Hu, B. Z.; Hu, T.; Huang, E. C.; Huang, H. X.; Huang, X. T.; Huang, Y. B.; Huber, P.; Huo, W.; Hussain, G.; Jaffe, D. E.; Jen, K. L.; Ji, X. P.; Ji, X. L.; Jiao, J. B.; Johnson, R. A.; Jones, D.; Kang, L.; Kettell, S. H.; Khan, A.; Kohn, S.; Kramer, M.; Kwan, K. K.; Kwok, M. W.; Langford, T. J.; Lau, K.; Lebanowski, L.; Lee, J.; Lee, J. H. C.; Lei, R. T.; Leitner, R.; Leung, J. K. C.; Li, C.; Li, D. J.; Li, F.; Li, G. S.; Li, Q. J.; Li, S.; Li, S. C.; Li, W. D.; Li, X. N.; Li, X. Q.; Li, Y. F.; Li, Z. B.; Liang, H.; Lin, C. J.; Lin, G. L.; Lin, S.; Lin, S. K.; Lin, Y.-C.; Ling, J. J.; Link, J. M.; Littenberg, L.; Littlejohn, B. R.; Liu, J. L.; Liu, J. C.; Loh, C. W.; Lu, C.; Lu, H. Q.; Lu, J. S.; Luk, K. B.; Ma, X. Y.; Ma, X. B.; Ma, Y. Q.; Malyshkin, Y.; Martinez Caicedo, D. A.; McDonald, K. T.; McKeown, R. D.; Mitchell, I.; Nakajima, Y.; Napolitano, J.; Naumov, D.; Naumova, E.; Ngai, H. Y.; Ochoa-Ricoux, J. P.; Olshevskiy, A.; Pan, H.-R.; Park, J.; Patton, S.; Pec, V.; Peng, J. C.; Pinsky, L.; Pun, C. S. J.; Qi, F. Z.; Qi, M.; Qian, X.; Qiu, R. M.; Raper, N.; Ren, J.; Rosero, R.; Roskovec, B.; Ruan, X. C.; Steiner, H.; Stoler, P.; Sun, J. L.; Tang, W.; Taychenachev, D.; Treskov, K.; Tsang, K. V.; Tull, C. E.; Viaux, N.; Viren, B.; Vorobel, V.; Wang, C. H.; Wang, M.; Wang, N. Y.; Wang, R. G.; Wang, W.; Wang, X.; Wang, Y. F.; Wang, Z.; Wang, Z.; Wang, Z. M.; Wei, H. Y.; Wen, L. J.; Whisnant, K.; White, C. G.; Whitehead, L.; Wise, T.; Wong, H. L. H.; Wong, S. C. F.; Worcester, E.; Wu, C.-H.; Wu, Q.; Wu, W. J.; Xia, D. M.; Xia, J. K.; Xing, Z. Z.; Xu, J. L.; Xu, Y.; Xue, T.; Yang, C. G.; Yang, H.; Yang, L.; Yang, M. S.; Yang, M. T.; Yang, Y. Z.; Ye, M.; Ye, Z.; Yeh, M.; Young, B. L.; Yu, Z. Y.; Zeng, S.; Zhan, L.; Zhang, C.; Zhang, C. C.; Zhang, H. H.; Zhang, J. W.; Zhang, Q. M.; Zhang, R.; Zhang, X. T.; Zhang, Y. M.; Zhang, Y. X.; Zhang, Y. M.; Zhang, Z. J.; Zhang, Z. Y.; Zhang, Z. P.; Zhao, J.; Zhou, L.; Zhuang, H. L.; Zou, J. H.; Daya Bay Collaboration

    2017-06-01

    The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 G Wth reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective 239Pu fission fractions F239 from 0.25 to 0.35, Daya Bay measures an average IBD yield σ¯f of (5.90 ±0.13 )×10-43 cm2/fission and a fuel-dependent variation in the IBD yield, d σf/d F239, of (-1.86 ±0.18 )×10-43 cm2/fission . This observation rejects the hypothesis of a constant antineutrino flux as a function of the 239Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1 σ . This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes 235U, 239Pu, 238U, and 241Pu. Based on measured IBD yield variations, yields of (6.17 ±0.17 ) and (4.27 ±0.26 )×10-43 cm2 /fission have been determined for the two dominant fission parent isotopes 235U and 239Pu. A 7.8% discrepancy between the observed and predicted 235U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.

  7. On Lunar Exospheric Column Densities and Solar Wind Access Beyond the Terminator from ROSAT Soft X-Ray Observations of Solar Wind Charge Exchange

    Science.gov (United States)

    Collier, Michael R.; Snowden, S. L.; Sarantos, M.; Benna, M.; Carter, J. A.; Cravens, T. E.; Farrell, W. M.; Fatemi, S.; Hills, H. Kent; Hodges, R. R.; hide

    2014-01-01

    We analyze the Rontgen satellite (ROSAT) position sensitive proportional counter soft X-ray image of the Moon taken on 29 June 1990 by examining the radial profile of the surface brightness in three wedges: two 19 deg wedges (one north and one south) 13-32 deg off the terminator toward the dark side and one wedge 38 deg wide centered on the antisolar direction. The radial profiles of both the north and the south wedges show significant limb brightening that is absent in the 38 deg wide antisolar wedge. An analysis of the soft X-ray intensity increase associated with the limb brightening shows that its magnitude is consistent with that expected due to solar wind charge exchange (SWCX) with the tenuous lunar atmosphere based on lunar exospheric models and hybrid simulation results of solar wind access beyond the terminator. Soft X-ray imaging thus can independently infer the total lunar limb column density including all species, a property that before now has not been measured, and provide a large-scale picture of the solar wind-lunar interaction. Because the SWCX signal appears to be dominated by exospheric species arising from solar wind implantation, this technique can also determine how the exosphere varies with solar wind conditions. Now, along with Mars, Venus, and Earth, the Moon represents another solar system body at which SWCX has been observed.

  8. Charge Exchange X-Ray Emission due to Highly Charged Ion Collisions with H, He, and H2: Line Ratios for Heliospheric and Interstellar Applications

    Science.gov (United States)

    Cumbee, R. S.; Mullen, P. D.; Lyons, D.; Shelton, R. L.; Fogle, M.; Schultz, D. R.; Stancil, P. C.

    2018-01-01

    The fundamental collisional process of charge exchange (CX) has been established as a primary source of X-ray emission from the heliosphere, planetary exospheres, and supernova remnants. In this process, X-ray emission results from the capture of an electron by a highly charged ion from a neutral atom or molecule, to form a highly excited, high-charge state ion. As the captured electron cascades down to the lowest energy level, photons are emitted, including X-rays. To provide reliable CX-induced X-ray spectral models to realistically simulate these environments, line ratios and spectra are computed using theoretical CX cross sections obtained with the multi-channel Landau-Zener, atomic-orbital close-coupling, molecular-orbital close-coupling, and classical trajectory Monte Carlo methods for various collisional velocities relevant to astrophysics. X-ray spectra were computed for collisions of bare and H-like C to Al ions with H, He, and H2 with results compared to available experimental data. Using these line ratios, XSPEC models of CX emission in the northeast rim of the Cygnus Loop supernova remnant and the heliosphere are shown as examples with ion velocity dependence.

  9. Measurement of radial profiles of density ratio of helium to hydrogen ion using charge exchange spectroscopy with two-wavelength spectrometer.

    Science.gov (United States)

    Ida, K; Yoshinuma, M; Wieland, B; Goto, M; Nakamura, Y; Kobayashi, M; Murakami, I; Moon, C

    2015-12-01

    Radial profiles of density ratio of helium to hydrogen ions are measured using the charge exchange spectroscopy technique with the two-wavelength spectrometer system in the large helical device. The two-wavelength spectrometer system consists of a dichroic mirror box, a spectrometer with two grating and two camera lenses, and one CCD detector. The dichroic mirror box is used to divide the light of one fiber from the plasma to two fibers, one for HeII (λ = 468.6 nm) and the other for H(α) (λ = 656.3 nm), that are connected to the entrance slit of the spectrometer to eliminate the interference between the HeII and the H(α) spectra on the CCD. This system provides a simultaneous measurement of helium and hydrogen ion density ratio at 8 exact same locations (8 spatial channels) with a time resolution of >40 ms in the wide range of the density ratio of 0.05-5.

  10. Experimental study of invariance violations in neutrino and antineutrino reactions at high energy

    International Nuclear Information System (INIS)

    Blaes, R.

    1983-06-01

    This work is dedicated to the study of the structure functions in neutrino-nucleon interactions and to the interpretation of observed violations of scaling invariance. The first chapter describes the experimental setting, the Cargamelle cloud chamber has been used. The second chapter presents the data analysis, the event selection methodology, the muon identification and the energy correction that takes into account the non-detected particles. We also present the bi-dimensional x and q 2 distribution of events that is necessary to the determination of the structure functions. In the third chapter we detail the theoretical basis of our analysis: we define relevant kinematic variables and we discuss the scale invariance in the light of the quark-parton model. The violations of the scale invariance are considered first in the formalism of quantum chromodynamics and then in the view of higher twist or mass corrections. The fourth chapter deals with the experimental determination of the structure functions and of the violations of the scaling invariance. (A.C.)

  11. Properties of the hadronic system produced in antineutrino proton interactions

    International Nuclear Information System (INIS)

    Musgrave, B.

    1979-01-01

    The separation of the hadronic system produced in anti νp charged-current reactions into the current and target fragmentation components is discussed. The current fragments show properties in good qualitative agreement with the expectations of the naive quark-parton model. In particular, there is no evidence for either a Q 2 - or X/sub BJ/-dependence of the fragmentation functions. 7 references

  12. Angular distributions of neutrino and antineutrino scatterings by electrons and gauge models

    International Nuclear Information System (INIS)

    Dass, G.V.

    1976-01-01

    Assuming a nonderivative point interaction, and Born approximation, the complete angular distributions for the scatterings of neutrinos and antineutrinos by electrons are obtained from only simple general considerations, without explicit calculation; generalisation to parton targets is noted. Two pairs of simple constraints on the angular distributions can be violated only if the interaction has a helicity-flipping component; this can serve to disfavour the large class of models which are purely helicity-conserving. Comparison is made with some explicit calculations done for some special cases of some of the results. (author)

  13. Experimental study of the nucleon longitudinal structure function in charged-current neutrino and antineutrino interactions

    International Nuclear Information System (INIS)

    Bergsma, F.; Dorenbosch, J.; Jonker, M.; Nieuwenhuis, C.; Allaby, J.V.; Amaldi, U.; Barbiellini, G.; Barone, L.; Capone, A.; Flegel, W.; Metcalf, M.; Panman, J.; Winter, K.; Abt, I.; Aspiazu, J.; Buesser, F.W.; Daumann, H.; Gall, P.D.; Metz, E.; Niebergall, F.; Ranitzsch, K.H.; Staehelin, P.; Baroncelli, A.; Bosio, C.; Tortora, L.; Borgia, B.; Diemoz, M.; Dore, U.; Ferroni, F.; Longo, E.; Luminari, L.; Monacelli, P.; De Notaristefani, F.; Pistilli, P.; Santoni, C.; Valente, V.

    1984-01-01

    The x dependence of the longitudinal structure function Fsub(L) was determined with the CHARM neutrino detector exposed to neutrino and antineutrino wide-band beams of the CERN 400 GeV SPS. The results show a clear deviation from the Callan-Gross relation. The amount and the x dependence of this deviation are in agreement with the contribution coming from a finite transverse momentum of the partons in the nucleon if both the intrinsic and perturbative QCD terms are taken into account. (orig.)

  14. Neutral current (anti)neutrino scattering: Relativistic mean field and superscaling predictions

    International Nuclear Information System (INIS)

    González-Jiménez, R.; Ivanov, M.V.; Barbaro, M.B.; Caballero, J.A.; Udias, J.M.

    2013-01-01

    We evaluate the neutral current quasi-elastic neutrino cross section within two nuclear models: the SuSA model, based on the superscaling behavior of electron scattering data, and the RMF model, based on relativistic mean field theory. We also estimate the ratio (νp→νp)/(νN→νN) and compare with the MiniBooNE experimental data, performing a fit of the parameters M A and g A (s) within the two models. Finally, we present our predictions for antineutrino scattering.

  15. Measurement of the neutron and proton structure functions from neutrino and antineutrino scattering in deuterium

    Science.gov (United States)

    Allasia, D.; Angelini, C.; Baldini, A.; Barlag, S.; Bertanza, L.; Bigi, A.; Bisi, V.; Bobisut, F.; Bolognese, T.; Borg, A.; Calimani, E.; Capiluppi, P.; Casali, R.; Ciampolillo, S.; Derkaoui, J.; Faccini-Turluer, M. L.; Fantechi, R.; Flaminio, V.; Frodesen, A. G.; Gamba, D.; Giacomelli, G.; Graziani, G.; Halsteinslid, A.; Hornaes, A.; Huzita, H.; Jongejans, B.; Lippi, I.; Loreti, M.; Louedec, C.; Mandrioli, G.; Marzari-Chiesa, A.; Nappi, A.; Pazzi, R.; Pierazzini, G. M.; Riccati, L.; Romero, A.; Rossi, A. M.; Sconza, A.; Serra-Lugaresi, P.; Tenner, A.; van Apeldoorn, G. W.; van Dam, P.; Vignaud, D.; Visser, C.; Wigmans, R.

    1984-02-01

    Data from an exposure of the BEBC bubble chamber filled with deuterium to neutrino and antineutrino wide band beams have been used to extract the x dependence of the structure functions for scattering on protons and neutrons and the fractional momentum distributions of the valence quarks and the antiquarks of different flavours. The difference F n2 - F p2 is compared with recent data from high energy μD scattering. A result is also obtained on the sum rule giving the difference between the number of up and down quarks in the nucleon.

  16. Charge exchange and energy loss of slowed down heavy ions channeled in silicon crystals; Echanges de charge et perte d'energie d'ions lourds ralentis, canalises dans des cristaux de silicium

    Energy Technology Data Exchange (ETDEWEB)

    Testa, E

    2005-10-15

    This work is devoted to the study of charge exchange processes and of the energy loss of highly charged heavy ions channeled in thin silicon crystals. The two first chapters present the techniques of heavy ion channeling in a crystal, the ion-electron processes and the principle of our simulations (charge exchange and trajectory of channeled ions). The next chapters describe the two experiments performed at the GSI facility in Darmstadt, the main results of which follow: the probability per target atom of the mechanical capture (MEC) of 20 MeV/u U{sup 91+} ions as a function of the impact parameter (with the help of our simulations), the observation of the strong polarization of the target electron gas by the study of the radiative capture and the slowing down of Pb{sup 81+} ions from 13 to 8,5 MeV/u in channeling conditions for which electron capture is strongly reduced. (author)

  17. Monte Carlo simulation of inclusive pionic reaction around resonance and higher energy perspectives

    International Nuclear Information System (INIS)

    Oset, E.; Salcedo, L.L.; Strottman, D.; Vicente, M.J.; Garcia-Recio, C.; Hernandez, E.

    1987-01-01

    We describe all the inclusive pionic reactions in a variety of nuclei around the resonance region by means of a microscopic many-body calculation that evaluates reaction probabilities, followed by a Monte Carlo simulation which follows the evolution of the pions. We also make an intrusion into the higher energy domain by paying attention to the absorption mechanisms and their repercussions in exclusive single-charge exchange reactions. 27 refs., 11 figs

  18. New (anti)neutrino results from the T2K experiment on CP violation in the lepton sector

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    T2K is a long-baseline neutrino experiment in which a muon neutrino beam produced by J-PARC in Tokai is sent 295 km across Japan to the Super-Kamiokande detector, to study neutrino oscillations via the disappearance of muon neutrinos and the appearance of electron neutrinos. Since the start of operations in 2010, T2K has conclusively observed muon neutrino to electron neutrino oscillations, opening the door to the observation of CP violation in neutrino mixing, and performed the most precise measurement of the muon neutrino disappearance parameters. In a joint analysis between these two modes, T2K placed its first constraints on the CP-violating phase delta. Starting in 2014, T2K has been running primarily with an antineutrino beam in order to study the corresponding antineutrino oscillations, resulting in leading measurements of the muon antineutrino disappearance parameters. The joint analysis of neutrino and antineutrino data indicates that CP-conserving parameters lie outside the 90% confidence interval....

  19. Measurement of the Antineutrino Double-Differential Charged-Current Quasi-Elastic Scattering Cross Section at MINERvA

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, Cheryl [Northwestern U.

    2016-01-01

    Next-generation neutrino oscillation experiments, such as DUNE and Hyper-Kamiokande, hope to measure charge-parity (CP) violation in the lepton sector. In order to do this, they must dramatically reduce their current levels of uncertainty, particularly those due to neutrino-nucleus interaction models. As CP violation is a measure of the difference between the oscillation properties of neutrinos and antineutrinos, data about how the less-studied antineutrinos interact is especially valuable. We present the MINERvA experiment's first double-differential scattering cross sections for antineutrinos on scintillator, in the few-GeV range relevant to experiments such as DUNE and NOvA. We also present total antineutrino-scintillator quasi-elastic cross sections as a function of energy, which we compare to measurements from previous experiments. As well as being useful to help reduce oscillation experiments' uncertainty, our data can also be used to study the prevalence of various cor relation and final-state interaction effects within the nucleus. We compare to models produced by different model generators, and are able to draw first conclusions about the predictions of these models.

  20. [Measurements of observables of pion-nucleon reactions]. Progress report

    International Nuclear Information System (INIS)

    Sadler, M.E.

    1985-01-01

    This document reports the progress of the research of pion reactions. These include (1) a study to measure observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/c, (2) differential cross section measurements at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. Individual experiments will be indexed separately

  1. Measurement of Neutrino and Antineutrino Total Charged-Current Cross Sections on Carbon with MINERvA

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Lu [Univ. of Pittsburgh, PA (United States)

    2017-01-01

    This thesis presents a measurement of charged-current inclusive cross sections of muon neutrino and antineutrino interaction on carbon, and antineutrino to neutrino cross section ratio, r, in the energy range 2 - 22 GeV, with data collected in the MINERA experiment. The dataset corresponds to an exposure of 3.2 x 1020 protons on target (POT) for neutrinos and 1.01020 POT for antineutrinos. Measurement of neutrino and antineutrino charged-current inclusive cross sections provides essential constraints for future long baseline neutrino oscillation experiment at a few GeV energy range. Our measured antineutrino cross section has an uncertainty in the range 6.1% - 10.5% and is the most precise measurement below 6 GeV to date. The measured r has an uncertainty of 5.0% - 7.5%. This is the rst measurement below 6 GeV since Gargamelle in 1970s. The cross sections are measured as a function of neutrino energy by dividing the eciency corrected charged-current sample with extracted uxes. Fluxes are obtained using the low- method, which uses low hadronic energy subsamples of charged-current inclusive sample to extract ux. Measured cross sections show good agreement with the prediction of neutrino interaction models above 7 GeV, and are about 10% below the model below 7 GeV. The measured r agrees with the GENIE model [1] over the whole energy region. The measured cross sections and r are compared with world data.

  2. Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Colin E. [Yale Univ., New Haven, CT (United States)

    2011-05-01

    Elucidating the nature of neutrino oscillation continues to be a goal in the vanguard of the efforts of physics experiment. As neutrino oscillation searches seek an increasingly elusive signal, a thorough understanding of the possible backgrounds becomes ever more important. Measurements of neutrino-nucleus interaction cross sections are key to this understanding. Searches for νμ → νe oscillation - a channel that may yield insight into the vanishingly small mixing parameter θ13, CP violation, and the neutrino mass hierarchy - are particularly susceptible to contamination from neutral current single π0 (NC 1π0) production. Unfortunately, the available data concerning NC 1π0 production are limited in scope and statistics. Without satisfactory constraints, theoretical models of NC 1π0 production yield substantially differing predictions in the critical Eν ~ 1 GeV regime. Additional investigation of this interaction can ameliorate the current deficiencies. The Mini Booster Neutrino Experiment (MiniBooNE) is a short-baseline neutrino oscillation search operating at the Fermi National Accelerator Laboratory (Fermilab). While the oscillation search is the principal charge of the MiniBooNE collaboration, the extensive data (~ 106 neutrino events) offer a rich resource with which to conduct neutrino cross section measurements. This work concerns the measurement of both neutrino and antineutrino NC 1π0 production cross sections at MiniBooNE. The size of the event samples used in the analysis exceeds that of all other similar experiments combined by an order of magnitude. We present the first measurements of the absolute NC 1π0 cross section as well as the first differential cross sections in both neutrino and antineutrino mode. Specifically, we measure single differential cross sections with respect to pion momentum and pion angle. We find the

  3. Calorimetric measurement of the SOX anti-neutrino source for sterile neutrino search

    Energy Technology Data Exchange (ETDEWEB)

    Altenmueller, Konrad; Agostini, Matteo; Papp, Laszlo; Schoenert, Stefan [Physik Department and Excellence Cluster Universe, Technische Universitaet Muenchen (Germany); Collaboration: Borexino-Collaboration

    2015-07-01

    A thermal calorimeter is under development to measure with <1% accuracy the heat release of the Cerium anti-neutrino source for the SOX experiment, which is looking for eV-scale sterile neutrinos. The heat release is proportional to the source activity and thus to the emitted neutrino flux, which is an important parameter of the experiment. The calorimeter design is based on a copper heat exchanger mounted around the source with integrated water lines for the heat extraction. Heat loss through conduction and radiation is minimized by suspending the set-up through Kevlar ropes and inserting it inside a thermalized vacuum tank with radiation shields. The device is currently being assembled and tested at TUM in Garching.

  4. Measurements of the charge exchange and dissociation cross-sections of the H{sub 2}+ ion in a wide energy range; Mesures des sections efficaces d'echange de charge et de dissociation des ions H{sub 2}{sup +} dans une large gamme d'energie (25 - 250 keV)

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-07-01

    The dissociation, ionisation, and charge exchange cross-sections of molecular hydrogen ions H{sub 2}{sup +} passing through various gases, have been measured as a function of the energy of the ions. The energy range studied was from 25 to 250 keV. The reaction products, analysed by a magnetic field according to their e/m ratio, are collected on scintillation detectors. Two methods have made it possible to separate the various reactions leading to the formation of particles having the same e/m ratio. The first separates the particles according to their energy, the other selects those arriving simultaneously on two different detectors. The results show a large variation in the charge exchange cross-section with the energy of the H{sub 2}{sup +} ions. The variations in the dissociation and ionisation cross-sections are less pronounced. For a given energy, the values of the cross-sections increase with the atomic weight of the target particles. These measurements have been extended to the case of H{sub 2}{sup +} ions passing through a target of charged particles. Preliminary results show an increase in the cross-sections as compared to the preceding case. Finally the scattering of the reaction products has been studied; this scattering is due to the fact that the molecules formed during a reaction are in an unstable state and the nuclei or atoms diverge from each other. (author) [French] Les sections efficaces de dissociation, d'ionisation et d'echange de charge d'ions hydrogene moleculaires H{sub 2}{sup +} traversant differents gaz, ont ete mesurees en fonction de l'energie des ions. La gamme d'energie exploree est comprise entre 25 et 250 keV. Les produits de reactions, analyses suivant leur rapport e/m par un champ magnetique, sont recus sur des detecteurs a scintillations. Deux methodes ont permis de separer les diverses reactions conduisant a la formation de particules ayant meme rapport e/m. L'une classe les particules secondaires en

  5. Reactions probing effects of quark clusters in nuclei

    International Nuclear Information System (INIS)

    Lassila, K.E.; Sukhatme, U.P.

    1988-01-01

    We study signatures of quark clusters in reactions which probe quarks in nuclei. We examine the EMC effect and use physical arguments to establish features of valence and ocean parton distributions in multiquark clusters. We predict from these distributions ratios of structure functions and cross sections measured with neutrino, antineutrinos and proton beams. It appears that a unique determination of the source of the EMC effect will be possible. 6 refs., 4 figs

  6. Experimental study of the nucleon structure functions and of the gluon distribution from charged-current neutrino and antineutrino interactions

    International Nuclear Information System (INIS)

    Bergsma, F.; Dorenbosch, J.; Jonker, M.; Nieuwenhuis, C.; Udo, F.; Allaby, J.V.; Amaldi, U.; Barbiellini, G.; Barone, L.; Capone, A.; Flegel, W.; Metcalf, M.; Panman, J.; Winter, K.; Abt, I.; Aspiazu, J.; Buesser, F.W.; Daumann, H.; Gall, P.D.; Metz, E.; Niebergall, F.; Ranitzsch, K.H.; Staehelin, P.

    1983-01-01

    Inclusive neutrino and antineutrino charged current interactions were studied in the CHARM detector exposed to neutrino and antineutrino Wide Band Beams of the CERN 400 GeV SPS. The x and Q 2 dependence of the structure functions F 2 and xF 3 and of the antiquark momentum distribution q were determined. The data have been interpreted in terms of QCD theory using the Furmanski-Petronzio method. In this way we have determined #betta#sub(LO)=[190 + 70 sub(-40)(stat)+-70 (syst.)] MeV and the structure functions of quarks and gluons without specific assumptions on their analytic dependence. The results agree with previous experiments which relied on model assumptions in the analysis. We conclude that the model independent simultaneous analysis of the xF 3 , F 2 , anti q structure functions gives a more reliable determination of the gluon distribution in the nucleon. (orig.)

  7. Measurement of total and differential cross sections of neutrino and antineutrino coherent π± production on carbon

    Science.gov (United States)

    Mislivec, A.; Higuera, A.; Aliaga, L.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Caceres v., G. F. R.; Cai, T.; Martinez Caicedo, D. A.; Carneiro, M. F.; Chavarria, E.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Gran, R.; Harris, D. A.; Hurtado, K.; Jena, D.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; McFarland, K. S.; Messerly, B.; Miller, J.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Nguyen, C.; Norrick, A.; Nuruzzaman, Paolone, V.; Perdue, G. N.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Tagg, N.; Valencia, E.; Wospakrik, M.; Yaeggy, B.; Zavala, G.; MinerνA Collaboration

    2018-02-01

    Neutrino induced coherent charged pion production on nuclei, ν¯ μA →μ±π∓A , is a rare inelastic interaction in which the four-momentum squared transferred to the nucleus is nearly zero, leaving it intact. We identify such events in the scintillator of MINERvA by reconstructing |t | from the final state pion and muon momenta and by removing events with evidence of energetic nuclear recoil or production of other final state particles. We measure the total neutrino and antineutrino cross sections as a function of neutrino energy between 2 and 20 GeV and measure flux integrated differential cross sections as a function of Q2 , Eπ, and θπ . The Q2 dependence and equality of the neutrino and antineutrino cross sections at finite Q2 provide a confirmation of Adler's partial conservation of axial current hypothesis.

  8. A feasibility study of boron-loaded liquid scintillator for the detection of electron anti-neutrinos

    CERN Document Server

    Wang, S C; Leung, R W S; Wang, S L; Chang, C Y; Chen Chi Ping; Cheng, K C; Ho, T I; Lai, W P; Liu, H M; Mao, Z P; Shih, I C; Wong, H T; Yu, Z Q

    1999-01-01

    Boron-loaded liquid scintillator offers some potential advantages as a detector for electron anti-neutrinos. A research program was carried out with the objective of developing such scintillators. The crucial feature is the pulse shape discrimination properties following the neutron capture by sup 1 sup 0 B. Results of the R and D efforts are presented. The feasibility and the technical difficulties of carrying out a full-scale neutrino experiment based on this approach are discussed. (author)

  9. SoLid: An innovative anti-neutrino detector for searching oscillations at the SCK• CEN BR2 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Yamiel, E-mail: yamiel.abreu@uantwerpen.be

    2017-02-11

    The SoLid experiment intends to search for active-to-sterile anti-neutrino oscillations at a very short baseline from the SCK• CEN BR2 research reactor (Mol, Belgium). A novel detector approach to measure reactor anti-neutrinos was developed based on an innovative sandwich of composite polyvinyl-toluene and {sup 6}LiF:ZnS(Ag) scintillators. The system is highly segmented and read out by a network of wavelength shifting fibers and SiPM. High experimental sensitivity can be achieved compared to other standard technologies thanks to the combination of high granularity, good neutron–gamma discrimination using {sup 6}LiF:ZnS(Ag) scintillator and precise localisation of the Inverse Beta Decay products. This technology can be considered as a new generation of an anti-neutrino detector. This compact system requires limited passive shielding and relies on spatial topology to determine the different classes of backgrounds. We will describe the principle of detection and the detector design. Particular focus on the neutron discrimination will be made, as well as on the capability to use cosmic muons for channel equalisation and energy calibration. The performance of the first 288 kg SoLid module (SM1), based on the data taken at BR2 from February to September 2015, will be presented. We will conclude with the next phase, which will start in 2016, and the future plans of the experiment.

  10. SoLid: An innovative anti-neutrino detector for searching oscillations at the SCK•CEN BR2 reactor

    Science.gov (United States)

    Abreu, Yamiel; SoLid Collaboration

    2017-02-01

    The SoLid experiment intends to search for active-to-sterile anti-neutrino oscillations at a very short baseline from the SCK•CEN BR2 research reactor (Mol, Belgium). A novel detector approach to measure reactor anti-neutrinos was developed based on an innovative sandwich of composite polyvinyl-toluene and 6LiF:ZnS(Ag) scintillators. The system is highly segmented and read out by a network of wavelength shifting fibers and SiPM. High experimental sensitivity can be achieved compared to other standard technologies thanks to the combination of high granularity, good neutron-gamma discrimination using 6LiF:ZnS(Ag) scintillator and precise localisation of the Inverse Beta Decay products. This technology can be considered as a new generation of an anti-neutrino detector. This compact system requires limited passive shielding and relies on spatial topology to determine the different classes of backgrounds. We will describe the principle of detection and the detector design. Particular focus on the neutron discrimination will be made, as well as on the capability to use cosmic muons for channel equalisation and energy calibration. The performance of the first 288 kg SoLid module (SM1), based on the data taken at BR2 from February to September 2015, will be presented. We will conclude with the next phase, which will start in 2016, and the future plans of the experiment.

  11. First Anti-neutrino Oscillation Results from the T2K Experiment

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Neutrinos are some of the most abundant but yet most elusive particles in the universe. They have almost no mass, only interact weakly and relatively little is known about their properties. Furthermore it has been firmly established over the last decade that neutrinos can undergo flavour transitions as mass and flavor eigenstates are not identical. These neutrino oscillations have been studied using natural sources as well as nuclear reactors or with neutrinos produced at accelerators. T2K is a long baseline neutrino oscillation beam that uses a beam of muon (anti-)neutrinos that is directed form J-PARC at the east cost of Japan over a distance of almost 300 km to the SuperKamiokande water Cherenkov detector in the west. The facility is complemented by a near detector complex 280 m downstream of the neutrino production target to characterise the beam and the neutrino interaction dynamics. T2K has taken data with a muon neutrino beam since early 2010 and is studying the disappearance of muon neutrinos as well...

  12. Scintillation light production, propagation and detection in the Stereo reactor antineutrino experiment

    Science.gov (United States)

    Buck, Christian; Lindner, Manfred; Roca, Christian

    2017-09-01

    The Stereo experiment’s detector has been optimized to observe reactor antineutrinos via inverse beta decay within a 1800 liter volume filled with Gadolinium-doped organic liquid scintillator (LS). The main requirements for the scintillator in Stereo are compatibility with detector materials as the acrylic vessels, transparency, light yield, pulse shape discrimination capabilities as well as chemical and optical stability over several years of data taking. With these conditions in mind, the composition of the LS is mainly a mix of 75% LAB, 20%PXE and 5% DIN combined with the two wavelength-shifters PPO and Bis-MSB. The final admixture after the full scale production lead to an attenuation length of more than 5 meters for optical photons of 430 nm. The scintillation light produced in the Gd-loaded target volume and the Gd-free outer crown is detected by 48 eight inch PMTs on top of the detector. A correct performance of the PMTs has been ensured through several tests. Common characteristics for PMTs as gain, single photoelectron peak, time behaviour, dark rate and afterpulse ratio were measured resulting in a complete agreement with the manufacturer values.

  13. Geneva University: Observation of electron-antineutrino disappearance at Daya Bay

    CERN Multimedia

    Université de Genève

    2012-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92 Monday 19 March 2012 COLLOQUE DE PHYSIQUE 5 p.m. - École de Physique, Auditoire Stueckelberg Observation of electron-antineutrino disappearance at Daya Bay  Professor Yifang Wang Institute of High Energy Physics of the Chinese Academy of Sciences Beijing The Daya Bay Reactor Neutrino Experiment, a multinational collaboration operating in the south of China, today reported the first results of its search for the last, most elusive piece of a long-standing puzzle: how is it that neutrinos can appear to vanish as they travel? The surprising answer opens a gateway to a new understanding of fundamental physics and may eventually solve the riddle of why there is far more ordinary matter than antimatter in the Universe today....

  14. Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

    Energy Technology Data Exchange (ETDEWEB)

    Asner, David M.; Burns, Kimberly A.; Campbell, Luke W.; Greenfield, Bryce A.; Kos, Marek S.; Orrell, John L.; Schram, Malachi; VanDevender, Brent A.; Wood, Lynn S.; Wootan, David W.

    2015-03-01

    The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

  15. Supernova relic electron neutrinos and anti-neutrinos in future large-scale observatories

    Energy Technology Data Exchange (ETDEWEB)

    Volpe, C.; Welzel, J. [Institut de Physique Nuclueaire, 91 - Orsay (France)

    2007-07-01

    We investigate the signal from supernova relic neutrinos in future large scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at present under study. We discuss that complementary information might be gained from the observation of supernova relic electron antineutrinos and neutrinos using the scattering on protons on one hand, and on nuclei such as oxygen, carbon or argon on the other hand. When determining the relic neutrino fluxes we also include, for the first time, the coupling of the neutrino magnetic moment to magnetic fields within the core collapse supernova. We present numerical results on both the relic {nu}{sub e} and {nu}-bar{sub e} fluxes and on the number of events for {nu}{sub e} + C{sup 12}, {nu}{sub e} + O{sup 16}, {nu}{sub e} + Ar{sup 40} and {nu}-bar{sub e} + p for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino properties, that still remain unknown. (authors)

  16. Measurement of Absolute Single and Double Charge Exchange Cross Sections for Si(7–10)+ at 0.88–2.50 KeV/u Impacting He and H2

    Science.gov (United States)

    Moradmand, A.; El Ghazaly, M. O. A.; Mahaptra, D. P.; Chutjian, A.

    2018-01-01

    First measurements are reported for total, absolute, single, and double charge-exchange (CE) cross sections for Si(7–10)+ ions in the solar wind (SW), colliding with the prevalent astrophysical species H2 and He found in comets, the interplanetary medium, and planetary atmospheres. Measurements are in the energy range 0.88–2.50 keV/u, corresponding to the energies of the “fast” and “slow” ion components of the SW. Limited agreement is found with single-exchange results calculated in the classical over-the-barrier model. These CE data are useful for understanding, in laboratory and astrophysical plasmas, photon emissions in the X-ray to visible energy range arising from resulting ion-stabilization steps.

  17. Search for the signature of a halo structure in the p(6He,6Li)n reaction

    International Nuclear Information System (INIS)

    Cortina-Gil, M.D.; Roussel-Chomaz, P.; Mittig, W.; Casandjian, J.M.; Chartier, M.; Alamanos, N.; Auger, F.; Fekou-Youmbi, V.; Blumenfeld, Y.; and others.

    1995-01-01

    The elastic scattering p( 6 He, 6 He)p and charge exchange reaction p( 6 He, 6 Li)n have been measured in reverse kinematics with a secondary 6 He beam. The angular distributions for these reactions were obtained. In the case of the charge exchange reaction, the ratio of the cross section for the Gamow-Teller transition to the ground state, and for the Fermi transition to the isobaric analog state is a measure of the relative strength of the two components of the exchange interaction. This ratio is found compatible with existing systematics for stable T=1 nuclei, and no clear signature of a halo structure was found in the present data. (author)

  18. O2(X3 Sigma- sub g) and O2(a1 Delta sub g) Charge Exchange with Simple Ions (Postprint)

    Science.gov (United States)

    2014-06-03

    during reaction in Eq. (3), which is highly exother- mic. Second, the vapor pressure of the aqueous solution was lowered, minimizing water contamination...states of iodine molecule: Experimental and theoretical study of the I 2 ( f 0 g + ) collisions with rare gas atoms J. Chem. Phys. 122, 204318 (2005...concentration determined by measuring the total pressure in the cell. Multiplying the total gas flow rate by the fractional abundance then gave the O2(a1

  19. Selected aspects of fusion reactions

    International Nuclear Information System (INIS)

    Lacroix, D.

    2003-01-01

    In this lecture, we present selected aspects of nuclear fusion. The importance of the initial geometry of the reaction and its relation to fusion barrier are first discussed. The effect of deformation leading to the notion of barrier distribution is then illustrated. After a brief overview of the advantages of macroscopic theories, the dynamics of nuclear system under large amplitude motion is reviewed. The di-nuclear concept is presented to understand the competition between fusion and quasi-fission. This concept is then generalized to account for the dissipative dynamics in multidimensional collective space. The last part of this lecture is devoted to new aspects encountered with radioactive beams specific properties of very extended neutron rich system, influence of pygmy or soft dipole resonances and charge exchange far from stability are discussed. (author)

  20. Around the laboratories: Dubna: Physics results and progress on bubble chamber techniques; Stanford (SLAC): Operation of a very rapid cycling bubble chamber; Daresbury: Photographs of visitors to the Laboratory; Argonne: Charge exchange injection tests into the ZGS in preparation for a proposed Booster

    CERN Multimedia

    1969-01-01

    Around the laboratories: Dubna: Physics results and progress on bubble chamber techniques; Stanford (SLAC): Operation of a very rapid cycling bubble chamber; Daresbury: Photographs of visitors to the Laboratory; Argonne: Charge exchange injection tests into the ZGS in preparation for a proposed Booster

  1. Messung der Impulsverteilung der Antiquarks im Nukleon aus der inklusiven tiefinelastischen Antineutrino Nukleon Reaktion ueber geladene Stroeme

    CERN Document Server

    Klasen, Hans Peter

    1981-01-01

    In this thesis the antiquark momentum distribution in the nucleus as a function of x and Q2 is determined. This determination is based on the measurement of the differential cross-section at high y for inclusive antineutrino nucleon charged current interactions. The portion of antineutrino scattering off quarks is corrected by the also measured neutrino cross-section. For the measurement of the cross-section 150 000 anti v- und 35 000 v-events, which were produced in the CERN wide band beam, in the energy range from 20 GeV to 160 GeV and 27 000 anti v- and 63 000 v-events measured in the narrow band beam in the energy range from 20 GeV to 200 GeV are used. The measurement was performed with the detector of the CERN-Dortmund-Heidelberg-Saclay collaboration. The detector serves at the same time as target, as hadron energy calorimeter and as muon spectrometer. The measured antiquark momentum distribution shows a strong rise for x<0.1 as a function of Q2. It will be shown that this scaling violation cannot be ...

  2. Search for sub-eV sterile neutrinos in the precision multiple baselines reactor antineutrino oscillation experiments

    Directory of Open Access Journals (Sweden)

    Shu Luo

    2015-10-01

    Full Text Available According to different effects on neutrino oscillations, the unitarity violation in the MNSP matrix can be classified into the direct unitarity violation and the indirect unitarity violation which are induced by the existence of the light and the heavy sterile neutrinos respectively. Of which sub-eV sterile neutrinos are of most interesting. We study in this paper the possibility of searching for sub-eV sterile neutrinos in the precision reactor antineutrino oscillation experiments with three different baselines at around 500 m, 2 km and 60 km. We find that the antineutrino survival probabilities obtained in the reactor experiments are sensitive only to the direct unitarity violation and offer very concentrated sensitivity to the two parameters θ14 and Δm412. If such light sterile neutrinos do exist, the active–sterile mixing angle θ14 could be acquired by the combined rate analysis at all the three baselines and the mass-squared difference Δm412 could be obtained by taking the Fourier transformation to the L/E spectrum. Of course, for such measurements to succeed, both high energy resolution and large statistics are essentially important.

  3. Final state interaction in the pd → pnp reaction at 1 GeV

    International Nuclear Information System (INIS)

    Deloff, A.

    1992-09-01

    The pd → pnp reaction at 1 GeV in both the direct and charge exchange channel has been investigated. The experimental data come from a line reversed beam-target experiment with 3.3 GeV/c deuterons incident on a proton target. In the direct channel data exhibit narrow structures in the np effective mass spectra: at threshold, at 2.02 GeV and at 2.12 GeV which have been seen before and we report on a new narrow enhancement at 1.95 GeV. In charge exchange channel the data show somewhat broader peak at 2.18 GeV. The data are explained by using a conventional approach, i.e. without sub-nucleonic degrees of freedom, but including the ΔN channel in NN scattering. 29 figs., 1 tab., 36 refs. (author)

  4. Measurement of the mixing leptonic parameter θ13 at the Double Chooz reactor antineutrino experiment

    International Nuclear Information System (INIS)

    Durand, V.

    2012-01-01

    The Double Chooz experiment aims at measuring the neutrino mixing parameter θ13 by studying the oscillations of de ν-bar e produced by the Chooz nuclear reactors located in France. The experimental concept consists in comparing the signal of two identical 10.3 m 3 detectors, allowing to cancel most of the experimental systematic uncertainties. The near detector, whose goal is the flux normalization and a measurement without oscillation, is expected to be delivered in 2013. The farthest detector from the source is taking data since April 2011 and is sensitive to θ 13 , which is expected to affect both the rate and the shape of the measured de ν-bar e . In this thesis, are first presented the Double Chooz experiment, with its ν-bar e source, its detection method, and the expected signal and backgrounds. In order to perform a selection, important quantities have to be reconstructed, calibrated, and saved in data files. The channel time offsets determination, the energy and vertex reconstruction algorithm CocoReco, the reconstruction packages of the Common Trunk, and the light trees maker Cheetah are especially presented. Concerning the data analysis, all the selection cuts and results for signal and backgrounds are discussed, particularly the multiplicity cut, the multiple off time window method, the lithium veto cut, and the cosmogenic 9 Li background studies. The Double Chooz experiment observed 8,249 de ν-bar e candidates in 227.93 days in its far detector only. The reactor antineutrino flux prediction used the Bugey 4 flux measurement after correction for differences in core composition. The expectation in case of no-oscillation is 8,937 events and this deficit is interpreted as evidence for ν-bar e disappearance. From a rate and shape analysis, is found sin 2 2θ = 0,109± 0,030 (stat) ± 0,025 (syst), with Δm 2 31 = 2,32 x 10 -3 eV 2 , while the no-oscillation hypothesis is even excluded at 2.9 σ. (author) [fr

  5. Anti-Neutrino Charged Current Quasi-Elastic Scattering in MINER$\

    Energy Technology Data Exchange (ETDEWEB)

    Chvojka, Jesse John [Univ. of Rochester, NY (United States)

    2012-01-01

    in neutrino interactions. We present the first cross-section measurement for MINER A, the differential cross-section dσ/dQ2 for muon anti-neutrino CCQE scattering on polystyrene scintillator (CH) as well as comparisons to several final state models.

  6. Direct nuclear reactions and the structure of atomic nuclei

    International Nuclear Information System (INIS)

    Osterfeld, F.

    1985-01-01

    The present thesis deals with two different aspects of direct nuclear reactions, namely on the one hand with the microscopic calculation of the imaginary optical potential for the elastic nucleon-nucleus scattering as well as on the other hand with the microscopic analysis of giant magnetic resonances in atomic nuclei which are excited by (p,n) charge-exchange reactions. In the first part of the thesis the imaginary part of the optical potential for the elastic proton- and neutron-nucleus scattering is microscopically calculated in the framework of the so called nuclear-structure approximation to the optical potential. The calculations are performed in the Feshbach formalism in second-order perturbation theory corresponding to an effective projectile-target-nucleon interaction. In the second part of this thesis in the framework of microscopic nuclear models a complete analysis of different A(p,n)B charge-exchange reactions at high incident energies 160 MeV 90 Zr(p,n) reaction three collective spin-isospin resonances could be uniquely identified. (orig./HSI) [de

  7. Charge-exchange products of BEVALAC projectiles

    International Nuclear Information System (INIS)

    Rasmussen, J.

    1982-11-01

    There is a substantial production of fragments of all masses lighter than the projectile, such fragments being centered in a narrow region of velocity space around the beam velocity. The exciting studies about anomalons deal with the curious enhanced reactivity of some of these secondary fragments. I direct attention here to the rather rare fragments of the same mass number as the projectile but differing in charge by one unit. We also keep track, as a frame of reference, of the products that have lost one neutron from the projectile

  8. Strength function of xenon 127 and cross section of 127I(νe, e-)127Xe reaction

    International Nuclear Information System (INIS)

    Lyutostanskij, Yu.S.; Shul'gina, N.B.

    1989-01-01

    The strenght functions S β (E) and the cross section of the reaction ν e + 127 I → e - + 127 Xe were calculated in the framework of the theory of finite Fermi-systems. The results obtained are used to estimate the possibility of using an iodine-xenon detector in the experiments with solar neutrinos and reactor antineutrinos. The advantages of the iodine-xenon detector over the chlorine-argon one are shown. 13 refs.; 6 figs.; 3 tabs

  9. Grazing incidence collisions of ions and atoms with surfaces: from charge exchange to atomic diffraction; Collisions rasantes d'ions ou d'atomes sur les surfaces: de l'echange de charge a la diffraction atomique

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, P

    2006-09-15

    This thesis reports two studies about the interaction with insulating surfaces of keV ions or atoms under grazing incidence. The first part presents a study of charge exchange processes occurring during the interaction of singly charged ions with the surface of NaCl. In particular, by measuring the scattered charge fraction and the energy loss in coincidence with electron emission, the neutralization mechanism is determined for S{sup +}, C{sup +}, Xe{sup +}, H{sup +}, O{sup +}, Kr{sup +}, N{sup +}, Ar{sup +}, F{sup +}, Ne{sup +} and He{sup +}. These results show the importance of the double electron capture as neutralization process for ions having too much potential energy for resonant capture and not enough for Auger neutralization. We have also studied the ionisation of the projectile and of the surface, and the different Auger-like neutralization processes resulting in electron emission, population of conduction band or excited state. For oxygen scattering, we have measured an higher electron yield in coincidence with scattered negative ion than with scattered atom suggesting the transient formation above the surface of the oxygen doubly negative ion. The second study deals with the fast atom diffraction, a new phenomenon observed for the first time during this work. Due to the large parallel velocity, the surface appears as a corrugated wall where rows interfere. Similarly to the Thermal Atom Scattering the diffraction pattern corresponds to the surface potential and is sensitive to vibrations. We have study the H-NaCl and He-LiF atom-surface potentials in the 20 meV - 1 eV range. This new method offers interesting perspectives for surface characterisation. (author)

  10. Gamow-Teller matrix elements from the C-12(d,He-2) and Mg-24(d,He-2) reactions at 170 MeV

    NARCIS (Netherlands)

    Baumer, C; Frekers, D; Schmidt, R; van den Berg, AM; Hannen, VM; Harakeh, MN; de Huu, MA; Wörtche, HJ; De Frenne, D; Hagemann, M; Heyse, J; Jacobs, E; Fujita, Y

    The Mg-24(d,He-2)Na-24 and the C-12(d,He-2)B-12 charge-exchange reactions have been studied at an incident energy of 170 MeV. The two protons in the S-1(0)(pp) state (indicated as He-2) were both momentum analyzed and detected by the same spectrometer and detector. Background-free He-2 spectra with

  11. Measurement of Neutrino and Antineutrino Charged-Current Inclusive Cross Sections with the MINERvA Detector

    Energy Technology Data Exchange (ETDEWEB)

    Devan, Joshua D. [College of William and Mary, Williamsburg, VA (United States)

    2015-01-01

    Neutrinos are a nearly massless, neutral particle in the Standard Model that only interact via the weak interaction. Experimental confirmation of neutrino oscillations, in which a neutrino created as a particular type (electron, muon or tau) can be observed as a different type after propagating some distance, earned the 2015 Nobel Prize in Physics. Neutrino oscillation experiments rely on accurate measurements of neutrino interactions with matter, such as that presented here. Neutrinos also provide a unique probe of the nucleus, complementary to electron scattering experiments. This thesis presents a measurement of the charged-current inclusive cross section for muon neutrinos and antineutrinos in the energy range 2 to 50 GeV with the MINERvA detector. MINERvA is a neutrino scattering experiment in the NuMI neutrino beam at Fermilab, near Chicago. A cross section measures the probability of an interaction occurring, measured here as a function of neutrino energy. To extract a cross section from data, the observed rate of interactions is corrected for detector efficiency and divided by the number of scattering nucleons in the target and the flux of neutrinos in the beam. The neutrino flux is determined with the low-$\

  12. Exclusive measurements of Δ excitation by the (3He,t) reaction

    International Nuclear Information System (INIS)

    Hennino, Th.

    1993-12-01

    The production of Δ in nuclei through charge exchange reactions induced by medium energy light projectiles has been undertaken at Laboratoire National Saturne. The possible existence of a pionic collective mode built on Δ-hole correlations has been proposed to explain medium effects which appeared in inclusive experiments. Using the Diogene 4π apparatus to detect the charged particles, the decay pattern of the Δ-hole states has been separated into its different modes. 3 of them deserve particular attention: the quasi free Δ production, the two nucleon absorption channel and the coherent mode. (author). 17 refs., 10 figs

  13. Monte-Carlo simulations on the antineutrino detection in heavy ion collisions

    International Nuclear Information System (INIS)

    Zude, E.

    1991-09-01

    Aim of the present thesis was to study, how far a large-area neutron detector with high efficiency operated at the Corporation for Heavy Ion Research in Darmstadt can also by applied for experiments on the sub-threshold antineutron production in heavy ion reactions for the study of the equation of state of highly excited nuclear matter. The experimental part consisted in the partition at the construction, the taking into operation, and the calibration measurements of the target-detector system, as well at the experiments with the LAND detector for the study of the Coulomb excitation of 136 Xe projectiles in the reaction 136 Xe+ 208 Pb at 700 respectively 800 MeV/u. Studies on the suppression of neutron events against antineutron events in the data acquisition in a typical SIS/LAND experiment on the antineutron production in heavy ion collisions were performed. The possibilities available on the level of the hardware trigger for the suppression of (multiple) neutron events were studied. Thereby resulted a reachable suppression factor of ≅ 10 -3 . Studies on the off-line analysis of antineutron events exhibited problems, which base on the high matter density in the detector. (orig./HSI) [de

  14. Measurements of cross-section of charge current inclusive of antineutrino scattering off nucleons using carbon, iron, lead and scintillator at MINER$\

    Energy Technology Data Exchange (ETDEWEB)

    Rakotondravohitra, Laza [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-08-18

    Neutrino physics is one of the most active fields in the domaine of high energy physics during the last century. The need of precise measurement of neutrino-nucleus interactions required by the neutrino oscillation experiments is a an exiting step. These measurements of cross-section are more than essential for neutrino oscillation experiment. Over the year, many measurements from varieties of experiments have been presented. MINERνA is one of the world leaders in measuring cross-section of neutrino and antineutrino -nucleus interactions. MINERνA is a neutrino-nucleus scattering experiment installed in the few-GeV NuMI beam line at Fermilab. In order to study nuclear dependence, MINERνA is endowed with different types of solid nuclear targets as well are liquid targets such as helium and water. This thesis presents measurements of cross-section of antineutrino scattering off nucleons using a variety of solid nuclear targets, carbon, iron, lead and also polystyrene scintillator (CH). The data set of antineutrino used for this analysis was taken between March and July 2010 with a total of 1.60X1020 protons on target. Charged current inclusive interactions were selected by requiring a positive muon and kinematics limitation of acceptance of the muon spectrometer are applied. The analysis requires neutrino energy between 2GeV et 20GeV and the angle of muon θmu < 17degree . The absolute cross-section # as function of neutrino energy and the differential cross-section dσ/ dxbj measured and shown the corresponding systematics for each nuclear targets. Data results are compared with prediction of the models implemented in the neutrino events generators GENIE 2.6.2 used by the experiment.

  15. Reactor anti-neutrinos: measurement of the θ13 leptonic mixing angle and search for potential sterile neutrinos

    International Nuclear Information System (INIS)

    Collin, A.

    2014-01-01

    The Double Chooz experiment aims to measure the θ 13 mixing angle through the disappearance -induced by the oscillation phenomenon - of anti-neutrinos produced by the Chooz nuclear reactors. In order to reduce systematic uncertainties, the experiment relies on the relative comparison of detected signals in two identical liquid scintillator detectors. The near one, giving the normalization of the emitted flux, is currently being built and will be delivered in spring 2014. The far detector, sensitive to θ 13 , is located at about one kilometer and is taking data since 2011. In this first phase of the experiment, the far detector data are compared to a prediction of the emitted neutrino flux to estimate θ 13 . In this thesis, the Double Chooz experiment and its analysis are presented, especially the background studies and the rejection of parasitic signals due to light emitted by photo-multipliers. Neutron fluxes between the different detector volumes impact the definition of the fiducial volume of neutrino interactions and the efficiency of detection. Detailed studies of these effects are presented. As part of the Double Chooz experiment, studies were performed to improve the prediction of neutrino flux emitted by reactors. This work revealed a deficit of observed neutrino rates in the short baseline experiments of last decades. This deficit could be explained by an oscillation to a sterile state. The Stereo project aims to observe a typical signature of oscillations: the distortion of neutrino spectra both in energy and baseline. This thesis presents the detector concept and simulations as well as sensitivity studies. Background sources and the foreseen shielding are also discussed. (author) [fr

  16. Study of the prospective usefulness of the detection of antineutrinos to monitor nuclear power plants for non proliferation purpose

    International Nuclear Information System (INIS)

    Cormon, S.

    2012-01-01

    The field of applied neutrino physics has shown new developments in the last decade. Indeed, the antineutrinos (n e ) emitted by a nuclear power plant depend on the composition of the fuel: thus their detection could be exploited for determining the isotopic composition of the reactor fuel. The International Atomic Energy Agency (IAEA) has expressed its interest in the potentialities of this detection as a new safeguard tool and has created an Ad Hoc working group devoted to this study. Our aim is to determine on the one hand, the current sensitivity reached with the n e detection and on the other hand, the sensitivity required to be useful to the IAEA and then we deduce the required performances required for a cubic meter detector. We will first present the physics on which our feasibility study relies: the neutrinos, the b-decay of the fission products (FP) and their conversion into ne spectra. We will then present our simulation tools: we use a package called MCNP Utility for Reactor Evolution (MURE), initially developed by CNRS/IN2P3 labs to study Generation IV reactors. Thanks to MURE coupled with nuclear data bases, we build the ne spectra by summing the FP contributions. The method is the only one that allows the ne spectra calculations associated to future reactors: we will present the predicted spectra for various innovative fuels. We then calculate the emitted ne associated to various concepts of current and future nuclear reactors in order to determine the sensitivity of the ne probe to various diversion scenarios, taking neutronics into account. The reactor studied are Canadian Deuterium, Pebble Bed Reactor and Fast Breeder Reactor. (author)

  17. A search for the K−pp bound state in the 3He(K−in-flight, n reaction at J-PARC

    Directory of Open Access Journals (Sweden)

    Hashimoto T.

    2014-03-01

    Full Text Available We have collected the first physics data of an experimental search for the simplest kaonic nuclear bound state, “K− pp”, by the 3He(K− n reaction at J-PARC. We confirmed that our spectrometer system works as designed and observed clear peak structure composed of the quasi-elastic K−“n” → K−n and the charge-exchange K−“p” → ¯̅K0n reactions in the forward neutron spectrum.

  18. A PRECISION MEASUREMENT OF THE NEUTRINO MIXING ANGLE THETA (SUB 13) USING REACTOR ANTINEUTRINOS AT DAYA BAY.

    Energy Technology Data Exchange (ETDEWEB)

    KETTELL, S.; ET AL.

    2006-10-16

    This document describes the design of the Daya Bay reactor neutrino experiment. Recent discoveries in neutrino physics have shown that the Standard Model of particle physics is incomplete. The observation of neutrino oscillations has unequivocally demonstrated that the masses of neutrinos are nonzero. The smallness of the neutrino masses (<2 eV) and the two surprisingly large mixing angles measured have thus far provided important clues and constraints to extensions of the Standard Model. The third mixing angle, {delta}{sub 13}, is small and has not yet been determined; the current experimental bound is sin{sup 2} 2{theta}{sub 13} < 0.17 at 90% confidence level (from Chooz) for {Delta}m{sub 31}{sup 2} = 2.5 x 10{sup -3} eV{sup 2}. It is important to measure this angle to provide further insight on how to extend the Standard Model. A precision measurement of sin{sup 2} 2{theta}{sub 13} using nuclear reactors has been recommended by the 2004 APS Multi-divisional Study on the Future of Neutrino Physics as well as a recent Neutrino Scientific Assessment Group (NUSAG) report. We propose to perform a precision measurement of this mixing angle by searching for the disappearance of electron antineutrinos from the nuclear reactor complex in Daya Bay, China. A reactor-based determination of sin{sup 2} 2{theta}{sub 13} will be vital in resolving the neutrino-mass hierarchy and future measurements of CP violation in the lepton sector because this technique cleanly separates {theta}{sub 13} from CP violation and effects of neutrino propagation in the earth. A reactor-based determination of sin{sup 2} 2{theta}{sub 13} will provide important, complementary information to that from long-baseline, accelerator-based experiments. The goal of the Daya Bay experiment is to reach a sensitivity of 0.01 or better in sin{sup 2} 2{theta}{sub 13} at 90% confidence level.

  19. A measurement of the cross section of the reaction $pp \\rightarrow n\\Delta^{++} (1232)$ at ISR energies

    CERN Document Server

    Kwak, N; Regler, Meinhard; Schmidt-Parzefall, W; Schubert, Klaus R; Winter, Klaus; Brandt, A; Dibon, Heinz; Flügge, G; Niebergall, F; Schumacher, P E; Aubert, Jean-Jacques; Broll, C; Coignet, G; Favier, Jean; Massonnet, Louis; Vivargent, M; Bartl, Walter; Eichinger, H; Gottfried, Christian; Neuhofer, Günther; Kwak, N; Nagy, E; Regler, M; Schmidt-Parzefall, W; Schubert, K R; Winter, K; Brandt, A no 2; Dibon, H no 2; Fluegge, G no 2; Niebergall, F no 2; Schumacher, P E no 2; Aubert, J J no 3; Broll, C no 3; Coignet, G no 3; Favier, J no 3; Massonnet, L no 3; Vivargent, M no 3; Bartl, W no 4; Eichinger, H no 4; Gottfried, C no 4; Neuhofer, G no 4

    1976-01-01

    A measurement of the cross section of the charge-exchange reaction pp to Delta /sup ++/(1232)n at square root s=23, 31 and 45 GeV at the CERN-ISR is reported. The energy dependences continues to follow a power law p/sub lab//sup -n/ with n=1.94+or-0.03 indicating dominance of one-pion exchange at the lowest ISR energy; there is some evidence for deviation from this at the higher ISR energies. (8 refs).

  20. Measurement of weak rates for stellar evolution via the (t,3He) reaction

    International Nuclear Information System (INIS)

    Zegers, R.G.T.

    2007-01-01

    The (t, 3 He) charge-exchange reaction has been developed as a tool to extract Gamow-Teller strengths on nuclei of importance for stellar evolution. A secondary triton beam of 115 MeV/nucleon is used, either produced from a primary α beam, or, since recently, from a primary 16 O beam. Here, the (t, 3 He) reaction is used to study the Gamow-Teller strength distribution in 58 Co via the 58 Ni(t, 3 He) reaction. The experimental results are compared with calculations in large-scale shell models using the kb3g and gxpf1 interactions, as well as existing data from 58 Ni(n, p) and 58 Ni(d, 2 He) experiments. The differences between the data and theoretical models are studied in terms of electron-capture rates in the pre-collapse stages of core-collapse supernovae

  1. Measurement of the muon antineutrino double-differential cross section for quasielastic-like scattering on hydrocarbon at Eν˜3.5 GeV

    Science.gov (United States)

    Patrick, C. E.; Aliaga, L.; Bashyal, A.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Caceres v., G. F. R.; Carneiro, M. F.; Chavarria, E.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Gran, R.; Han, J. Y.; Harris, D. A.; Henry, S.; Hurtado, K.; Jena, D.; Kleykamp, J.; Kordosky, M.; Le, T.; Lu, X.-G.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; McFarland, K. S.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nowak, G. M.; Nuruzzaman, Paolone, V.; Perdue, G. N.; Peters, E.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Teklu, A. M.; Valencia, E.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; Zhang, D.; Miner ν A Collaboration

    2018-03-01

    We present double-differential measurements of antineutrino charged-current quasielastic scattering in the MINERvA detector. This study improves on a previous single-differential measurement by using updated reconstruction algorithms and interaction models and provides a complete description of observed muon kinematics in the form of a double-differential cross section with respect to muon transverse and longitudinal momentum. We include in our signal definition zero-meson final states arising from multinucleon interactions and from resonant pion production followed by pion absorption in the primary nucleus. We find that model agreement is considerably improved by a model tuned to MINERvA inclusive neutrino scattering data that incorporates nuclear effects such as weak nuclear screening and two-particle, two-hole enhancements.

  2. A new measurement of the ratio of the cross sections of muon-neutrino and muon-antineutrino scattering on electrons

    International Nuclear Information System (INIS)

    Bergsma, F.; Dorenbosch, J.; Allaby, J.V.; Amaldi, U.; Barbiellini, G.; Baubillier, M.; Busi, C.; Flegel, W.; Grancagnolo, F.; Lanceri, L.; Metcalf, M.; Nieuwenhuis, C.; Panman, J.; Plunkett, R.; Santoni, C.; Winter, K.; Abt, I.; Aspiazu, J.; Buesser, F.W.; Daumann, H.; Gall, P.D.; Hebbeker, T.; Niebergall, F.; Schuett, P.; Staehelin, P.; Barone, L.; Borgia, B.; Capone, A.; Diemoz, M.; Dore, U.; Ferroni, F.; Longo, E.; Luminari, L.; Monacelli, P.; Notaristefani, F. de; Rome Univ.; Morganti, S.; Valente, V.

    1984-01-01

    A new experimental determination of the electro-weak mixing angle thetasub(W) is reported based on a second exposure of the CHARM calorimeter to the CERN-SPS wide-band beam. The ratio R of muon-neutrino- and muon-antineutrino-electron scattering cross sections has been determined from a sample of 37+-10 and 35+-10 events. The experimental result is R=1.26 (+0.72-0.45), corresponding to a value of sin 2 thetasub(W)=0.216+-0.055. The total sample of events collected in the CHARM calorimeter during the two exposures is (83+-16)νsub(μ)e events and (112+-21)anti νsub(μ)e events, leading to the final result sin 2 thetasub(W)=0.215+-0.032. The systematic error is estimated to be +-0.012. (orig.)

  3. Measurement of the neutral to charged current cross section ratios in neutrino and antineutrino nucleon interactions and determination of the Weinberg angle

    International Nuclear Information System (INIS)

    Abramowicz, H.; Groot, J.G.H. de; Hansl-Kozanecka, T.; Knobloch, J.; May, J.; Navarria, F.L.; Palazzi, P.; Para, A.; Ranjard, F.; Rothberg, J.; Schlatter, D.; Steinberger, J.; Taureg, H.; Rueden, W. von; Wahl, H.; Wotschak, J.; Duda, J.; Eisele, F.; Klasen, H.P.; Kleinknecht, K.; Lierl, H.; Pollmann, D.; Pszola, B.; Renk, B.; Willutzki, H.J.; Dydak, F.; Flottmann, T.; Geweniger, C.; Hepp, V.; Krolikowski, J.; Tittel, K.; Bloch, P.; Bloch-Devaux, B.; Guyot, C.; Loucatos, S.; Maillard, J.; Merlo, J.P.; Peyaud, B.; Rander, J.; Savoy-Navarro, A.; Turlay, R.; He, J.T.; Ruan, T.Z.; Wu, W.M.

    1985-01-01

    The cross section ratios of neutral and charged current interactions induced by neutrinos and antineutrinos in iron have been measured in the 200 GeV narrow-band beam at the CERN SPS. We find Rsub(ν)=0.301+-0.007 and Rsub(anti ν)=0.363+-0.015 for a hadron energy cut of 10 GeV. The results are in agreement with the standard model of electroweak interactions. In the MS renormalization scheme at the scale of the W boson mass sin 2 Osub(w)(msub(w))=0.226+-0.012 is obtained, where the error represents the experimental uncertainty. The theoretical uncertainty is estimated to be Δ sind 2 Osub(w)=+-0.006. (orig.)

  4. Magnetic Dipole and Gamow-Teller Modes in Neutrino-Nucleus Reactions: Impact on Supernova Dynamics and Nucleosynthesis

    International Nuclear Information System (INIS)

    Neumann-Cosel, P. von; Byelikov, A.; Richter, A.; Shevchenko, A.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Fujita, H.; Heger, A.; Kolbe, E.; Langanke, K.; Martinez-Pinedo, G.

    2006-01-01

    Some aspects of the importance of neutrino-induced reactions on nuclei within supernova physics are discussed. It is argued that important constraints on the experimentally unknown cross sections can be obtained from experimental studies of the nuclear response in selected cases. Examples are neutral-current induced reactions on fp-shell nuclei extracted from high-resolution inelastic electron scattering data providing the M1 strength distributions and the production of the exotic heavy, odd-odd nuclei 138La and 180Ta through charged-current reactions dominated by Gamow-Teller transitions. The Gamow-Teller strength can deduced from the (3He,t) charge-exchange reaction at zero degree

  5. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2002-01-01

    Full text: Department of Nuclear Reactions has had a very productive year. We have carried out our work in close collaborations with physicists from many laboratories, home and foreign. The following reports cover three major domains of our activities: nuclear, material and atomic physics. * Nuclear physics: In collaboration with scientists from Ukraine experimental studies of nuclear reaction induced by heavy ions from the Warsaw Cyclotron have been performed. The aim of the experiments is to study nuclear reactions leading to the exotic light nuclei in exit channels and energy dependence of the nucleus - nucleus interactions. Proton induced charge-exchange reactions were investigated theoretically by means of multistep-direct model. Good agreement with the experimental data was achieved. A novel approach to the problem of the nuclear liquid → gas phase transition was proposed, based on synergetics - a domain of science dealing with self-organization in macroscopic systems. Decay properties of the Roper resonance were studied. Final analysis of the analysing powers for the polarized deuterons scattered on protons was accomplished. Experimental programme of the near-threshold meson production in proton - proton scattering has been started in collaboration with Forschungszentrum. Juelich. * Atomic physics: Spectra of the X-rays emitted by energetic sulphur ions scattered off carbon atoms were analysed in order to study the role of the multiple charge states of the inner shells in the dynamics of the collision process. Ionization probabilities in collision of oxygen ions with gold atoms were measured. The observed disagreement of the experimental data with the theoretical predictions suggest a strong effect generated by the sub-shell couplings. * Materials research: Ion channelling method was applied to investigate transformation of the defects in Al x Ga 1-x As crystalline layers. Activities of our colleagues in didactics have grown considerably. Lectures

  6. Studies of isovector excitations in nuclei by neutron-induced reactions

    International Nuclear Information System (INIS)

    Nilsson, L.

    1987-01-01

    In this paper isovector excitations in nuclei, in particular the giant isovector quadrupole resonance in spherical nuclei, will be discussed. Several methods to investigate this excitation have been used, e.g. inelastic electron scattering and charge-exchange reactions. An alternative method to study isovector E2 resonances in nuclei, based on the radiative capture of fast neutrons, will be presented. Results from such experiments performed at the tandem accelerator laboratories in Los Alamos and Uppsala will be presented and discussed in terms of the direct-semidirect capture model. As a separate issue, the preparations being undertaken at Uppsala for studies of isovector excitations in nuclei by means of the (n,p) reaction will be described. A schematic lay-out of the experiment will be presented together with some relevant neutron beam parameters. Among isovector excitations to be studied by this method are the isovector monopole resonance and the Gamow-Teller resonance. 54 references, 6 figures, 1 table

  7. Reaction Automata

    OpenAIRE

    Okubo, Fumiya; Kobayashi, Satoshi; Yokomori, Takashi

    2011-01-01

    Reaction systems are a formal model that has been introduced to investigate the interactive behaviors of biochemical reactions. Based on the formal framework of reaction systems, we propose new computing models called reaction automata that feature (string) language acceptors with multiset manipulation as a computing mechanism, and show that reaction automata are computationally Turing universal. Further, some subclasses of reaction automata with space complexity are investigated and their la...

  8. CeLAND: search for a 4th light neutrino state with a 3 PBq 144Ce-144Pr electron antineutrino generator in KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    Gando, A; Gando, Y; Hayashida, S; Ikeda, H; Inoue, K; Ishidoshiro, K; Ishikawa, H; Koga, M; Matsuda, R; Matsuda, S; Mitsui, T; Motoki, D; Nakamura, K; Oki, Y; Otani, M; Shimizu, I; Shirai, J; Suekane, F; Suzuki, A; Takemoto, Y; Tamae, K; Ueshima, K; Watanabe, H; Xu, BD; Yamada, S; Yamauchi, Y; Yoshida, H; Cribier, M; Durero, M; Fischer, V; Gaffiot, J; Jonqueres, N; Kouchner, A; Lasserre, T; Leterme, D; Letourneau, A; Lhuillier, D; Mention, G; Rampal, G; Scola, L; Veyssiere, C; Vivier, M; Yala, P; Berger, BE; Kozlov, A; Banks, T; Dwyer, D; Fujikawa, BK; Han, K; Kolomensky, YG; Mei, Y; O' Donnell, T; Decowski, P; Markoff, DM; Yoshida, S; Kornoukhov, VN; Gelis, TVM; Tikhomirov, GV; Learned, JG; Maricic, J; Matsuno, S; Milincic, R; Karwowski, HJ; Efremenko, Y; Detwiler, A; Enomoto, S

    2017-05-12

    The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq (75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the center or next to a large low-background liquid scintillator detector. The antineutrino generator will be produced by the Russian reprocessing plant PA Mayak as early as 2014, transported to Japan, and deployed in the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015. KamLAND's 13 m diameter target volume provides a suitable environment to measure the energy and position dependence of the detected neutrino flux. A characteristic oscillation pattern would be visible for a baseline of about 10 m or less, providing a very clean signal of neutrino disappearance into a yet-unknown, sterile neutrino state. This will provide a comprehensive test of the electron dissaperance neutrino anomalies and could lead to the discovery of a 4th neutrino state for Δm$2\\atop{new}$ ≳ 0.1 eV2 and sin2(2θnew) > 0.05.

  9. Coherent pion production in the {sup 12}C and {sup 40}Ca by the (3 He,t{pi}{sup +}) charge exchange reaction at 2 GeV; Production coherente de pions dans les noyaux {sup 12}C, {sup 40}Ca, par reaction d`echange de charge ({sup 3}He, t{pi}{sup +}) a 2 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Farhi, Laurent [Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

    1997-10-13

    The coherent pion production process on nuclei is defined as the excitation of the first excited state of the nucleon, the delta(1232) resonance, creating a delta-hole state. This state propagates through the nuclear medium and then decays in a single pion, living the target nuclei in its ground state. In the nuclei, the attractive interaction between delta-hole states in the spin-longitudinal channel shifts down the effective mass of the delta and induces a collective state of excitation. The nuclear response in the longitudinal channel of interaction can be studied experimentally through the resonance decay coherent process triggered by a probe coupling longitudinally with the delta and selected by the target form factor. The ({sup 3}He, t) probe at 2 GeV on nuclei and the experimental set-up SPES IV-Pi have been used to study this decay process. A simulation program using GEANT and including theoretical consideration, knowledge of previous experimental results and the experimental properties of the set-up, have demonstrated the capability of the experiment for this study. The setting of the PCOS-IV acquisition system of multiwire proportional chambers and of the development and use of programs for treatment and analysis of experimental data have been necessary steps to make the experiment at Laboratoire National SATURNE as well as to obtain physical parameters in order to exhibit the coherent process. Nevertheless, the angular distribution of coherent pions differ from the theoretical predictions. Several hypotheses involving the experimental set-up and physical processes have been investigated in order to account for such distributions. (author) 44 refs., 68 figs., 7 tabs.

  10. The non-analog double charge exchange transition /sup 12/C(π/sup +/,π/sup -/)/sup 12/O/sub (g.s.)/ and /sup 16/O(π/sup +/,π/sup -/)/sup 16/Ne/sub (g.s.)/

    International Nuclear Information System (INIS)

    Wei-hsing, M.; Si-wen, W.; Gao-you, Z.; Chung-Kuang, C.; Zhen-rong, Y.; Shu-ping, Z.

    1986-01-01

    We proposed six possible reason exchange current mechanism for pion induced non-analog double charge exchange transition on /sup 12/C(π/sup +/, π/sup -/)/sup 12/O(g.s.) and /sup 16/O(π/sup +/, π/sup -/)/sup 16/N/sub e/(g.s.). Under the model, the authors calculated 164 MeV angular distribution. The theoretical results are compared with the existed data and are in a good agreement with the experimental data available. It strongly indicates that the non-analog DCX process is basically a diffractive process through double isobar excitation on a single nucleon and the dominant contribution to the process comes from one of the six diagrams, that is a π/sup +/ collides with a neutron to excite this neutron into an isobar Δ(1232) with charge of one unit; subsequently, the Δ/sup +/ decays to give π/sup +/Δ/sup o/ and then produced π/sup +/ is absorbed by the second target neutron which will be then turned to a proton. Meanwhile the traveling Δ/sup o/ finally decays into π/sup -/P so that the course of the process under consideration here is ended

  11. SOLAR-WIND ION-DRIVEN X-RAY EMISSION FROM COMETARY AND PLANETARY ATMOSPHERES: MEASUREMENTS AND THEORETICAL PREDICTIONS OF CHARGE-EXCHANGE CROSS-SECTIONS AND EMISSION SPECTRA FOR O{sup 6+} + H{sub 2}O, CO, CO{sub 2}, CH{sub 4}, N{sub 2}, NO, N{sub 2}O, AND Ar

    Energy Technology Data Exchange (ETDEWEB)

    Machacek, J. R. [Atomic and Molecular Physics Laboratory, Research School of Physics and Engineering, The Australian National University, Canberra 2601 (Australia); Mahapatra, D. P. [Department of Physics, Utkal University, Bhubaneswar 751004 (India); Schultz, D. R. [Department of Physics, Univ. of North Texas, Denton, TX 76203 (United States); Ralchenko, Yu. [Atomic Spectroscopy Group, National Institute of Standards and Technology, Gaithersburg, MD 20899-8422 (United States); Moradmand, A.; El Ghazaly, M. O. A.; Chutjian, A. [Astrophysics and Space Sciences Section, Jet Propulsion Laboratory/Caltech, Pasadena, CA 91109 (United States)

    2015-08-10

    Relevant to modeling and understanding X-ray emission from cometary and planetary atmospheres, total cross-sections for 1.17 and 2.33 keV/u O{sup 6+} colliding with H{sub 2}O, CO, CO{sub 2}, CH{sub 4}, N{sub 2}, NO, N{sub 2}O, and Ar have been measured for the processes of single, double, and triple charge exchanges. Using these measurements as benchmarks, synthetic emission spectra spanning the X-ray, UV, and visible range have been calculated based on theoretical treatment of the transfer of between one and six electrons from the target neutrals to the projectile ion, followed by radiative and non-radiative decay of the highly excited states produced in these collisions. The results help add to the base of knowledge required to simulate ion-neutral processes in astrophysical environments; refine the present understanding of these fundamental atomic processes; and guide future observations, laboratory measurements, and theoretical predictions.

  12. The electron antineutrino angular correlation coefficient a in free neutron decay. Testing the standard model with the aSPECT-spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Borg, Michael

    2011-02-04

    The {beta}-decay of free neutrons is a strongly over-determined process in the Standard Model (SM) of Particle Physics and is described by a multitude of observables. Some of those observables are sensitive to physics beyond the SM. For example, the correlation coefficients of the involved particles belong to them. The spectrometer aSPECT was designed to measure precisely the shape of the proton energy spectrum and to extract from it the electron anti-neutrino angular correlation coefficient a. A first test period (2005/2006) showed the ''proof-of-principles''. The limiting influence of uncontrollable background conditions in the spectrometer made it impossible to extract a reliable value for the coefficient a (published in 2008). A second measurement cycle (2007/2008) aimed to under-run the relative accuracy of previous experiments ({delta}a)/(a)=5%. I performed the analysis of the data taken there which is the emphasis of this doctoral thesis. A central point are background studies. The systematic impact of background on a was reduced to ({delta}a{sup (syst.)})/(a)=0.61 %. The statistical accuracy of the analyzed measurements is ({delta}a{sup (stat.)})/(a){approx}1.4 %. Besides, saturation effects of the detector electronics were investigated which were initially observed. These turned out not to be correctable on a sufficient level. An applicable idea how to avoid the saturation effects is discussed in the last chapter. (orig.)

  13. The electron antineutrino angular correlation coefficient a in free neutron decay. Testing the standard model with the aSPECT-spectrometer

    International Nuclear Information System (INIS)

    Borg, Michael

    2011-01-01

    The β-decay of free neutrons is a strongly over-determined process in the Standard Model (SM) of Particle Physics and is described by a multitude of observables. Some of those observables are sensitive to physics beyond the SM. For example, the correlation coefficients of the involved particles belong to them. The spectrometer aSPECT was designed to measure precisely the shape of the proton energy spectrum and to extract from it the electron anti-neutrino angular correlation coefficient a. A first test period (2005/2006) showed the ''proof-of-principles''. The limiting influence of uncontrollable background conditions in the spectrometer made it impossible to extract a reliable value for the coefficient a (published in 2008). A second measurement cycle (2007/2008) aimed to under-run the relative accuracy of previous experiments (δa)/(a)=5%. I performed the analysis of the data taken there which is the emphasis of this doctoral thesis. A central point are background studies. The systematic impact of background on a was reduced to (δa (syst.) )/(a)=0.61 %. The statistical accuracy of the analyzed measurements is (δa (stat.) )/(a)∼1.4 %. Besides, saturation effects of the detector electronics were investigated which were initially observed. These turned out not to be correctable on a sufficient level. An applicable idea how to avoid the saturation effects is discussed in the last chapter. (orig.)

  14. Neutrino reactions in hot and dense matter

    International Nuclear Information System (INIS)

    Lohs, Andreas

    2015-01-01

    In this thesis, neutrino reactions in hot and dense matter are studied. In particular, this work is concerned with neutrino-matter interactions that are relevant for neutrino transport in core-collapse supernovae (CCSNe). The majority of the energy from a CCSN is released in the form of neutrinos. Accurate understanding and computation of these interactions is most relevant to achieve sufficiently reliable predictions for the evolution of CCSNe and other related question such as the production of heavy elements or neutrino oscillations. For this purpose this work follows the combined approach of searching for new important neutrino reactions and improving the computation of those reactions that are already implemented. First we estimate the relevance of charged-current weak interactions that include muon-neutrinos or muons, as well as the role of neutron decay for neutrino transport in CCSNe. All of these reactions were previously neglected in CCSN-simulations. We derive and compute the matrix element and subsequent semi-analytic expressions for transport properties like the inverse mean free path of the new reactions. It is found that these reactions are important for muon neutrinos and low energy electron antineutrinos at very high densities in the protoneutron star surface. Consequently their implementation might lead to several changes in the prediction of CCSNe signatures such as the nucleosynthesis yields. Second we improve the precision in the computation of well known neutrino-nucleon reactions like neutrino absorption on neutrons. We derive semi-analytic expressions for transport properties that use less restrictive approximations while keeping the computational demand constant. Therefore we consider the full relativistic kinematics of all participating particles i.e. allowing for relativistic nucleons and finite lepton masses. Also the weak magnetism terms of the matrix elements are explicitly included to all orders. From our results we suggest that the

  15. Neutrino reactions in hot and dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Lohs, Andreas

    2015-04-13

    In this thesis, neutrino reactions in hot and dense matter are studied. In particular, this work is concerned with neutrino-matter interactions that are relevant for neutrino transport in core-collapse supernovae (CCSNe). The majority of the energy from a CCSN is released in the form of neutrinos. Accurate understanding and computation of these interactions is most relevant to achieve sufficiently reliable predictions for the evolution of CCSNe and other related question such as the production of heavy elements or neutrino oscillations. For this purpose this work follows the combined approach of searching for new important neutrino reactions and improving the computation of those reactions that are already implemented. First we estimate the relevance of charged-current weak interactions that include muon-neutrinos or muons, as well as the role of neutron decay for neutrino transport in CCSNe. All of these reactions were previously neglected in CCSN-simulations. We derive and compute the matrix element and subsequent semi-analytic expressions for transport properties like the inverse mean free path of the new reactions. It is found that these reactions are important for muon neutrinos and low energy electron antineutrinos at very high densities in the protoneutron star surface. Consequently their implementation might lead to several changes in the prediction of CCSNe signatures such as the nucleosynthesis yields. Second we improve the precision in the computation of well known neutrino-nucleon reactions like neutrino absorption on neutrons. We derive semi-analytic expressions for transport properties that use less restrictive approximations while keeping the computational demand constant. Therefore we consider the full relativistic kinematics of all participating particles i.e. allowing for relativistic nucleons and finite lepton masses. Also the weak magnetism terms of the matrix elements are explicitly included to all orders. From our results we suggest that the

  16. Reaction π-p → π0n in the 15-40 GeV/c momentum range

    International Nuclear Information System (INIS)

    Apel, W.D.; Augenstein, K.H.; Krueger, M.; Mueller, H.; Schinzel, D.; Schneider, H.; Sigurdsson, G.; Bertolucci, E.; Mannelli, I.; Pierazzini, G.M.; Quaglia, M.; Scribano, A.; Sergiampietri, F.; Vincelli, M.L.; Donskov, S.V.; Inyakin, A.V.; Johnson, R.; Kachanov, V.A.; Krasnokutsky, R.N.; Lednev, A.A.; Mikhailov, Yu.V.; Prokoshkin, Yu. D.; Shuvalov, R.S.; Toropin, A.N.; Leder, G.; Steuer, M.

    1979-01-01

    A high statistics measurement of the reaction π - p → π 0 n has been performed at the Serpukhov accelerator for 15, 20, 25, 30 and 40 GeV/c incident pion momentum using the NICE set-up with its associated 648-channel hodoscope spectrometer for γ-ray detection. More than 3 million charge-exchange events have been recorded in total. It is found that the spin-flip and non-spin-flip amplitudes can be parametrized, for small mod(t) as exponentials with the same slopes to within a few per cent. Also the behaviour of the differential cross section for small and medium mod(t) agrees with the prediction of a geometrical s-channel model which describes binary reactions in terms of a complex pole b 0 (s). The imaginary part of this universal pole, Im b 0 (s), has been determined and found to be growing logarithmically with s. (Auth.)

  17. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  18. Solar wind charge exchange observed through the lunar exosphere

    Czech Academy of Sciences Publication Activity Database

    Robertson, I. P.; Sembay, S.; Stubbs, T. J.; Kuntz, K. D.; Collier, M. R.; Cravens, T. E.; Snowden, S. L.; Hills, H. K.; Porter, F. S.; Trávníček, Pavel M.; Carter, J. A.; Read, A. M.

    2009-01-01

    Roč. 36, - (2009), L21102/1-L21102/5 ISSN 0094-8276 Institutional research plan: CEZ:AV0Z30420517 Keywords : lunar exosphere * solar wind * X-rays Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.204, year: 2009

  19. Charge exchange between low energy Si ions and Cs adatoms

    Czech Academy of Sciences Publication Activity Database

    Chen, X.; Šroubek, Zdeněk; Yarmoff, J. A.

    2008-01-01

    Roč. 602, č. 2 (2008), s. 620-629 ISSN 0039-6028 R&D Projects: GA AV ČR IAA1067401; GA MŠk MEB060715 Institutional research plan: CEZ:AV0Z20670512 Keywords : ion-surface impact * scattering * silicon * alkali metals Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.731, year: 2008

  20. Track structure for low energy ions including charge exchange processes

    International Nuclear Information System (INIS)

    Uehara, S.; Nikjoo, H.

    2002-01-01

    The model and development is described of a new generation of Monte Carlo track structure codes. The code LEAHIST simulates full slowing down of low-energy proton history tracks in the range 1 keV-1 MeV and the code LEAHIST simulates low-energy alpha particle history tracks in the range 1 keV-8 MeV in water. All primary ion interactions are followed down to 1 keV and all electrons to 1 eV. Tracks of secondary electrons ejected by ions were traced using the electron code KURBUC. Microdosimetric parameters derived by analysis of generated tracks are presented. (author)

  1. Experimental study on the influence of charge exchange on the stopping power in the interaction of chlorine with a gas and a deuterium plasma; Etude experimentale de l`influence des echanges de charges sur le pouvoir d`arret dans l`interaction d`ions chlore avec un gaz et un plasma de deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Nectoux, Marie [Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

    1998-01-06

    This thesis is placed in the context of the physics of energy deposition of a multicharged heavy ion beam in matter at intermediate energies. The experiment gave measurements of energy loss as a function of final charge state for chlorine ions at 1.7 MeV/u in deuterium gas or plasma. In this way, we explore the influence of charge state evolution, depending on experimentally measured capture and ionization cross sections and the electron density of the target, on energy loss. The target is cylindrical and enclosed by two fast valves. The plasma is created in the gas by a discharge, which induces a magnetic perturbation of the beam (lens effect). This effect induces a divergent and misaligned outgoing beam. A simulation including charge state and velocity evolution of the projectile in flight in the magnetic field has been made in order to optimize beam analysis, to reach a precision better than 10{sup -3} in energy measurement. This study led to removal of the target to the `Split Pole`, a refocusing magnetic spectrometer. The first results obtained clearly show the dependence of energy loss on exit charge and especially on its evolution in the target. This is explained in terms of the lengths covered by the projectile in its successive charge states in the target, which depends on target electron density and the medium considered. In plasma, we observed an energy distribution with exit charge twice that observed in gas, because of a strong decrease of charge exchange. A comparison of data obtained in gas with stopping power calculated from Bethe-Bloch-Barkas theory leads to the necessity of including spatial extension of the projectile charge in the theory. (author) 81 refs., 62 figs., 5tabs.

  2. Models of direct reactions and quantum pre-equilibrium for nucleon scattering on spherical nuclei

    International Nuclear Information System (INIS)

    Dupuis, M.

    2006-01-01

    When a nucleon collides with a target nucleus, several reactions may occur: elastic and inelastic scatterings, charge exchange... In order to describe these reactions, different models are involved: the direct reactions, pre-equilibrium and compound nucleus models. Our goal is to study, within a quantum framework and without any adjustable parameter, the direct and pre-equilibrium reactions for nucleons scatterings off double closed-shell nuclei. We first consider direct reactions: we are studying nucleon scattering with the Melbourne G-matrix, which represents the interaction between the projectile and one target nucleon, and with random phase approximation (RPA) wave functions which describe all target states. This is a fully microscopic approach since no adjustable parameters are involved. A second part is dedicated to the study of nucleon inelastic scattering for large energy transfer which necessarily involves the pre-equilibrium mechanism. Several models have been developed in the past to deal with pre-equilibrium. They start from the Born expansion of the transition amplitude which is associated to the inelastic process and they use several approximations which have not yet been tested. We have achieved some comparisons between second order cross sections which have been calculated with and without these approximations. Our results allow us to criticize some of these approximations and give several directions to improve the quantum pre-equilibrium models. (author)

  3. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    1999-01-01

    Full text: The Department of Nuclear Reactions had a very productive year. The following reports cover three major domains of our activities: nuclear, material and atomic physics. One of the current questions in modern nuclear physics is question of the phase transitions in nuclear matter. Our physicists, the members of the ALADIN Collaboration at Gesellschaft fuer Schwerionenforschung, participated in new experiments exploring properties of highly excited nuclear matter and the phenomenon of the liquid - gas phase transition. The experiments yielded a number of important results. Details can be found in the three short reports presented in this volume. Structure of a nucleon is another important subject of nuclear science research. In the last year energy region of Δ resonance has been investigated by means of charge exchange reaction. The experiment was performed at Laboratory National Saturne in Saclay by SPESIV-π collaboration consisting of physicist from Institute of Nuclear Physics Orsay, Niels Bohr Institute Copenhagen and from our Department. The main achievement of the experiment was evidence for a Δ - hole attraction in the spin longitudinal channel. Reactions induced by radioactive ion beams such as 6 He recently attract a lot of interest. There exist some evidences that the 6 He nucleus has a two-neutron halo structure similar to that well established for 11 Li. An analysis of 6 He + 4 He scattering data reported in this volume revealed some similarities between the loosely bound 6 Li nucleus and the neutron rich 6 He. Research in material physics has focused on two basic topics: a crystallographic model of uranium dioxide, a material currently used as a nuclear fuel and transformations of defects in GaAs crystals at low temperature. The investigations have been carried out in a wide collaboration with scientists from the University of Jena, Research Center Karlsruhe and Centre de Spectrometrie Nucleaire Orsay. Some experiments have been performed at

  4. The two-body electrodisintegration of 4He studied through the (e,e'p) reaction

    International Nuclear Information System (INIS)

    Brand, J.F.J. van den; Jans, E.; Lapikas, L.; Vries, C. de; Witt Huberts, P.K.A. de; Laget, J.M.

    1991-01-01

    Coincidence cross sections obtained with the (e,e'p) reaction are presented for the 4 He nucleus. From the measurements, performed in non-parallel kinematics at a relative p- 3 H kinetic energy in the center-of-mass system of 75 MeV, the proton-triton momentum distribution for recoil momenta up to 350 MeV/c has been extracted. The results show a strong dependence on the kinematical configuration. In order to study this in more detail we extended the 4 He(e,e'p) 3 H experiments to other kinematics, both parallel and non-parallel, and compare these data to phenomenological and microscopic calculations. The phenomenological treatment consists of a distorted-wave impulse approximation (DWIA) analysis using an optical potential. Charge-exchange effects in the final state are accounted for through coupled-channels calculations using the Lane formalism. These phenomenological calculations do not agree with the data. The microscopic calculation, which employs a diagrammatic treatment including the charge-exchange process (e,e'n)(n,p), proton rescattering effects and the contributions from meson-exchange currents, accounts fairly well for the empirical observations. The momentum dependence of the data is compared with theoretical calculations obtained with the VMC and ATMS variational methods for the Urbana and RSC nucleon-nucleon potentials. The results for the Urbana V14 NN potential, including corrections to PWIA using the microscopic model, are in good agreement with the data. The (e,e'n)(n,p) two-step contribution turns out to be an important ingredient for obtaining a satisfactory description of the 4 He(e,e'p) 3 H cross sections. Sum-rule results are presented and the data are compared to results of (p,2p) and other (e,e'p) experiments. (orig.)

  5. Charged-particle transfer reactions and nuclear astrophysics problems

    International Nuclear Information System (INIS)

    Artemov, S.V.; Yarmukhamedov, R.; Yuldashev, B.S.; Burtebaev, N.; Duysebaev, A.; Kadyrzhanov, K.K.

    2002-01-01

    In the report a review of the recent results of calculation of the astrophysical S-factors S(E) for the D(α, γ) 6 Li, 3 He(α, γ) 7 Be, 7 Be(p, γ) 8 Be, 12,13 C(p, γ) 13, 14 N and 12 C(p,γ) 16 O* reactions at extremely low energies E, including value E=0 , performed within the framework of a new method taking into account the additional information about the nuclear vertex constant (Nc) (or the respective asymptotic normalization coefficient) are presented. The required values of Nc can be obtained from an analysis of measured differential cross-sections of proton and α-particle transfer reactions (for example A( 3 He,d)B, 6 Li(d, 6 Li)d, 6 Li(α, 6 Li)α, 12 C( 6 Li, d) 16 O* etc.). A comparative analysis between the results obtained by different authors is also done. Taking into account an important role of the NVC's values for the nuclear astrophysical A(p, γ)B and A(α, γ)B reactions, a possibility of obtaining the reliable NVC values for the virtual decay B→A+p and B→A+α from the analysis of differential cross sections both sub- and above-barrier A( 3 He, d) and A( 6,7 Li, 2,3 H)B reactions is discussed in detail. In this line the use the isochronous cyclotron U-150 M, the 'DC-60' heavy ion machine and electrostatic charge-exchanging accelerator UKP-2-1 of Institute of Nuclear Physics of National Nuclear Center of the Republic of Kazakhstan for carrying out the needed experiments is considered and the possibility of the obtained data application for the astrophysical interest is also discussed

  6. Excitation functions of pion reactions on 14N, 16O, and 19F through the (3,3) resonance

    International Nuclear Information System (INIS)

    Jacob, N.P. Jr.; Markowitz, S.S.

    1976-01-01

    Cross sections for pion-induced reactions of the form (π,πN) and more complex spallation reactions of the form (π,X) have been measured from 50--550 MeV on the target nuclei 14 N, 16 O, and 19 F using the secondary pion beams at the Lawrence Berkeley Laboratory 184-inch synchrocyclotron and the Clinton P. Anderson Meson Physics Facility. The dominance of the (3,3) free-particle resonance is seen in all excitation functions determined in this work. Relative to the 12 C(π/sup plus-or-minus/,πN) 11 C reactions, the (π/sup plus-or-minus/,πN) reactions on 14 N, 16 O, and 19 F have magnitudes of 0.2, 1, and 0.7, respectively. The cross section ratio R=sigma (π - ,π - n)/sigma (π + ,π N) =1.68+-0.18 for 14 N at 188+-15 MeV, 1.68+-0.05 for 16 O at 188+-9 MeV, and 1.68+-0.03 for 19 F at 178+-2 MeV incident pion energy. The results from this work are compared to previous pion work, analogous proton-induced reactions, Monte Carlo intranuclear cascade-evaporation calculations, and to a semiclassical nucleon charge-exchange model which convincingly explains the (π,πN) reaction mechanism in the (3,3) resonance region

  7. Reaction mechanisms

    International Nuclear Information System (INIS)

    Nguyen Trong Anh

    1988-01-01

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported [fr

  8. Capture reactions

    NARCIS (Netherlands)

    Endt, P.M.

    1956-01-01

    Capture reactions will be considered here from the viewpoint of the nuclear spectroscopist. Especially important to him are the capture of neutrons, protons, and alpha particles, which may proceed through narrow resonances, offering a well defined initial state for the subsequent deexcitation

  9. Allergic reactions

    Science.gov (United States)

    ... that don't bother most people (such as venom from bee stings and certain foods, medicines, and pollens) can ... person. If the allergic reaction is from a bee sting, scrape the ... more venom. If the person has emergency allergy medicine on ...

  10. cycloaddition reactions

    Indian Academy of Sciences (India)

    Unknown

    ... has shown very severe limitations in predicting the regioselectivity. In comparison,. DFT-based descriptors are better suited to model the regioselectivity of cycloaddition reactions. Acknowledgements. GG thanks the Council of Scientific and Industrial. Research for a fellowship. References. 1. Winkler J D 1996 Chem. Rev.

  11. Multi-step direct reactions at low energies

    International Nuclear Information System (INIS)

    Marcinkowski, A.; Marianski, B.

    2001-01-01

    Full text: The theory of the multistep direct (MSD) reactions of Feshbach, Kerman and Koonin has for quite some time become a subject of controversy due to the bi orthogonal distorted waves involved in the transition amplitudes describing the MSD cross sections. The bi orthogonal wave functions result in non-normal DWBA matrix elements, that can be expressed in terms of normal DWBA matrix elements multiplied by the inverse elastic scattering S-matrix. It has been argued that the enhancing inverse S-factors are washed out by averaging over energy in the continuum. As a result normal DWBA matrix elements are commonly used in practical calculations. Almost all analyses of inelastic scattering and charge-exchange reactions using the DWBA matrix elements have concluded that nucleon emission at low energies can be described as one-step reaction mainly. On the other hand, it has been shown that the limits imposed by the energy weighted sum rules (EWSR's) on transition of given angular momentum transfer lead to a significant reduction of the one step cross section that can be compensated by the enhanced MSD cross sections obtained with the use of the non-normal DWBA matrix elements. Very recently the MSD theory of FKK was modified to include collective excitations and the non-normal DWBA matrix elements and the prescription for calculations of the cross sections for the MSD reactions was given. In the present paper we present the results of the modified theory used for describing the 93 Nb (n,xn) 93 Nb reaction at incident energy of 20 MeV and the 65 Cu (p,xn) 65 Zn reaction at 27 MeV. The results show enhanced contributions from two-, three- and four step reactions. We investigate the importance of the multi-phonon, multi particle hole and the mixed particle hole-phonon excitations in neutron scattering to the continuum. We also show the importance of the different sequences of collisions of the leading continuum nucleon that contribute to the MSD (p,n) reaction. When all

  12. Review of Reactor Antineutrino Experiments

    OpenAIRE

    Djurcic, Zelimir

    2012-01-01

    As discussed elsewhere, the measurement of a non-zero value for $\\theta_{13}$ would open up a wide range of possibilities to explore CP-violation and the mass hierarchy. Experimental methods to measure currently the unknown mixing angle $\\theta_{13}$ include accelerator searches for the $\

  13. Spallation reactions

    International Nuclear Information System (INIS)

    Cugon, J.

    1996-01-01

    Spallation reactions dominate the interactions of hadrons with nuclei in the GeV range (from ∼ 0.1 to ∼ 10 GeV). They correspond to a sometimes important ejection of light particles leaving most of the time a residue of mass commensurate with the target mass. The main features of the experimental data are briefly reviewed. The most successful theoretical model, namely the intranuclear cascade + evaporation model, is presented. Its physical content, results and possible improvements are critically discussed. Alternative approaches are shortly reviewed. (author)

  14. Study of the reaction K-p→anti K0n at momenta of 25 and 40 GeV/c

    International Nuclear Information System (INIS)

    Apel, W.D.; Mueller, H.; Schneider, H.

    1977-01-01

    Measurements were made of the differential cross sections for the charge exchange of K - mesons on protons at momenta of 25 and 40 GeV/c using a high-precision spectrometer with no magnetic field. In the range 5-40 GeV/c the reaction cross section follows a power-law dependence psub(K - )sup(-1.52). In the small momentum transfer region (-t 2 sub(π) a minimum is observed, similar to that discovered at lower energies. The differential cross sections at t=0 are considerably less than those predicted by the Regge-pole model. The parameters of the effective trajectory are determined. (Auth.)

  15. Nuclear reactions

    International Nuclear Information System (INIS)

    Corner, J.; Richardson, K.; Fenton, N.

    1990-01-01

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  16. Gamow-Teller transitions and neutron-proton-pair transfer reactions

    Science.gov (United States)

    Van Isacker, P.; Macchiavelli, A. O.

    2018-05-01

    We propose a schematic model of nucleons moving in spin-orbit partner levels, j = l ±1/2, to explain Gamow-Teller and two-nucleon transfer data in N = Z nuclei above 40Ca. Use of the LS coupling scheme provides a more transparent approach to interpret the structure and reaction data. We apply the model to the analysis of charge-exchange, 42Ca(3He,t)42Sc, and np-transfer, 40Ca(3He,p)42Sc, reactions data to define the elementary modes of excitation in terms of both isovector and isoscalar pairs, whose properties can be determined by adjusting the parameters of the model (spin-orbit splitting, isovector pairing strength and quadrupole matrix element) to the available data. The overall agreement with experiment suggests that the approach captures the main physics ingredients and provides the basis for a boson approximation that can be extended to heavier nuclei. Our analysis also reveals that the SU(4)-symmetry limit is not realized in 42Sc.

  17. Measuring nuclear reaction cross sections to extract information on neutrinoless double beta decay

    Science.gov (United States)

    Cavallaro, M.; Cappuzzello, F.; Agodi, C.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Branchina, V.; Bussa, M. P.; Calabrese, S.; Calabretta, L.; Calanna, A.; Calvo, D.; Carbone, D.; Chávez Lomelí, E. R.; Coban, A.; Colonna, M.; D’Agostino, G.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; de Faria, P. N.; Ferraresi, C.; Ferreira, J. L.; Finocchiaro, P.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia, U.; Giraudo, G.; Greco, V.; Hacisalihoglu, A.; Kotila, J.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lavagno, A.; La Via, F.; Lay, J. A.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lo Presti, D.; Lubian, J.; Medina, N.; Mendes, D. R.; Muoio, A.; Oliveira, J. R. B.; Pakou, A.; Pandola, L.; Petrascu, H.; Pinna, F.; Reito, S.; Rifuggiato, D.; Rodrigues, M. R. D.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Sgouros, O.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Tudisco, S.; Vsevolodovna, R. I. M.; Wheadon, R. J.; Yildirin, A.; Zagatto, V. A. B.

    2018-02-01

    Neutrinoless double beta decay (0vββ) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research “beyond Standard Model” and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0vββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extract information on the 0vββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0vββ.

  18. Chain reaction

    International Nuclear Information System (INIS)

    Balogh, Brian.

    1991-01-01

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  19. Evolved Models for Elementary Particles and Atoms Require Alternating Neutrino/Antineutrino Pairs Along Interlocked or Looped Strings. Traveling Waves, TW, and Standing Waves, SW, Alternate at Nodal Notches

    Science.gov (United States)

    McLeod, Roger David; McLeod, David Matthew

    2009-05-01

    Our hydrogen atom interacts with a neutron star. Its stringy TW/SW electron is cut by a neutrino scissor that instantly becomes its end anti-node. The string has one extra neutrino in 100,000. Antimatter remains concealed. Our Dumbo Proton of a TW state is similarly cut. Inside the star, electron string/spring compresses 100,000 and 1836 times more, to proton's linear mass density. Electrostatics encourages that caboose, stringy electron, to couple with a cut proton. Linear charge densities neutralize while composite length contracts 20%. The writhing string evicts an antineutrino at closure on Pauli's authority, becoming Mickey Neutron, with looped quarks. Unstable Mickey Neutron has his ear notch forced into an ear notch of stable Dumbo Proton, achieving immortality in this deuteron marriage. Tritium is in a m'enage a trois. Alpha Nucleus has a # grid. Meta state Ne-20 predicts alpha eviction to O-16. Schr"odinger finally prevails, so string theory and Wave Mechanics can prosper.

  20. Reaction πN → ππN near threshold

    International Nuclear Information System (INIS)

    Frlez, E.

    1993-11-01

    The LAMPF E1179 experiment used the π 0 spectrometer and an array of charged particle range counters to detect and record π + π 0 , π 0 p, and π + π 0 p coincidences following the reaction π + p → π 0 π + p near threshold. The total cross sections for single pion production were measured at the incident pion kinetic energies 190, 200, 220, 240, and 260 MeV. Absolute normalizations were fixed by measuring π + p elastic scattering at 260 MeV. A detailed analysis of the π 0 detection efficiency was performed using cosmic ray calibrations and pion single charge exchange measurements with a 30 MeV π - beam. All published data on πN → ππN, including our results, are simultaneously fitted to yield a common chiral symmetry breaking parameter ξ =-0.25±0.10. The threshold matrix element |α 0 (π 0 π + p)| determined by linear extrapolation yields the value of the s-wave isospin-2 ππ scattering length α 0 2 (ππ) = -0.041±0.003 m π -1 , within the framework of soft-pion theory

  1. Reaction πN → ππN near threshold

    Energy Technology Data Exchange (ETDEWEB)

    Frlez, Emil [Univ. of Virginia, Charlottesville, VA (United States)

    1993-11-01

    The LAMPF E1179 experiment used the π0 spectrometer and an array of charged particle range counters to detect and record π+π0, π0p, and π+π0p coincidences following the reaction π+p → π0π+p near threshold. The total cross sections for single pion production were measured at the incident pion kinetic energies 190, 200, 220, 240, and 260 MeV. Absolute normalizations were fixed by measuring π+p elastic scattering at 260 MeV. A detailed analysis of the π0 detection efficiency was performed using cosmic ray calibrations and pion single charge exchange measurements with a 30 MeV π- beam. All published data on πN → ππN, including our results, are simultaneously fitted to yield a common chiral symmetry breaking parameter ξ =-0.25±0.10. The threshold matrix element |α00π+p)| determined by linear extrapolation yields the value of the s-wave isospin-2 ππ scattering length α$2\\atop{0}$(ππ) = -0.041±0.003 m$-1\\atop{π}$-1, within the framework of soft-pion theory.

  2. Catalysis of Photochemical Reactions.

    Science.gov (United States)

    Albini, A.

    1986-01-01

    Offers a classification system of catalytic effects in photochemical reactions, contrasting characteristic properties of photochemical and thermal reactions. Discusses catalysis and sensitization, examples of catalyzed reactions of excepted states, complexing ground state substrates, and catalysis of primary photoproducts. (JM)

  3. On Thermonuclear Reaction Rates

    OpenAIRE

    Haubold, H. J.; Mathai, A. M.

    1996-01-01

    Nuclear reactions govern major aspects of the chemical evolution of galaxies and stars. Analytic study of the reaction rates and reaction probability integrals is attempted here. Exact expressions for the reaction rates and reaction probability integrals for nuclear reactions in the cases of nonresonant, modified nonresonant, screened nonresonant and resonant cases are given. These are expressed in terms of H-functions, G-functions and in computable series forms. Computational aspects are als...

  4. Effect of free-particle collisions in high energy proton and pion-induced nuclear reactions

    International Nuclear Information System (INIS)

    Jacob, N.P. Jr.

    1975-07-01

    The effect of free-particle collisions in simple ''knockout'' reactions of the form (a,aN) and in more complex nuclear reactions of the form (a,X) was investigated by using protons and pions. Cross sections for the 48 Ti(p,2p) 47 Sc and the 74 Ge(p,2p) 73 Ga reactions were measured from 0.3 to 4.6 GeV incident energy. The results indicate a rise in (p,2p) cross section for each reaction of about (25 +- 3) percent between the energies 0.3 and 1.0 GeV, and are correlated to a large increase in the total free-particle pp scattering cross sections over the same energy region. Results are compared to previous (p,2p) excitation functions in the GeV energy region and to (p,2p) cross section calculations based on a Monte Carlo intranuclear cascade-evaporation model. Cross section measurements for (π/sup +-/, πN) and other more complex pion-induced spallation reactions were measured for the light target nuclei 14 N, 16 O, and 19 F from 45 to 550 MeV incident pion energy. These measurements indicate a broad peak in the excitation functions for both (π,πN) and (π,X) reactions near 180 MeV incident energy. This corresponds to the large resonances observed in the free-particle π + p and π - p cross sections at the same energy. Striking differences in (π,πN) cross section magnitudes are observed among the light nuclei targets. The experimental cross section ratio sigma(π - ,π - n)/sigma(π + ,πN) at 180 MeV is 1.7 +- 0.2 for all three targets. The experimental results are compared to previous pion and analogous proton-induced reactions, to Monte Carlo intranuclear cascade-evaporation calculations, and to a semi-classical nucleon charge exchange model. (108 references) (auth)

  5. [Adverse reactions to insulin].

    Science.gov (United States)

    Liñana, J J; Montoro, F J; Hernández, M D; Basomba, A

    1997-07-01

    The prevalence of allergic reactions to insuline has decreased during the last few years. Probably this is due to the use of the newly-developed recombinant human insuline. At present, adverse reactions to insuline occur in 5-10% of patients on therapy with insuline. Adverse reactions may be local (more frequent) or systemic (rare). Insuline resistance consists in a different type of immunological reaction. Diagnosis of allergy to insuline is based on clinical history and cutaneous and serological tests. Treatment depends upon the severity of the reaction. When insuline is indispensable despite a previous allergic reaction, a desensitization protocol may be implemented.

  6. Towards an unified microscopic approach of the description of the nuclear structure and reaction

    International Nuclear Information System (INIS)

    Hoang, Sy Than

    2009-09-01

    This thesis contains 3 main parts. The first one: nuclear matter. The motivation of the study is to establish a link between the bare nucleon-nucleon interaction and nuclear matter properties. The properties of nuclear matter are examined using finite range effective interactions either derived from the Brueckner theory or determined in a purely phenomenological way. Skyrme-type interactions are also used for comparison. We have focused our discussion on several main aspects: the pressure ins symmetric nuclear matter and in neutron matter, the density dependence of the symmetric energy S and the nuclear matter incompressibility. The second part: the structure of finite nuclei and of the inner crust of neutrons stars. We present the non-relativistic HF and HF-BCS approaches in coordinate representation using finite-range density-dependent interactions in both the mean field and pairing channels. An iterative scheme is used for solving the integral-differential HF equations. We have studied the doubly magic nuclei, the Sn isotopes and the possible occurrence of bubble structures in the nuclei O 22 , Si 34 , Ar 46 and Ar 68 . We have also examined the different zones of the inner crust of neutron stars. The third part: nuclear reactions. Using the same effective interactions derived from the Brueckner theory we have performed a coupled channel analysis of (p,n) charge exchange reactions at 35 and 45 MeV incident energies on Ca 48 , Zr 90 , Sn 120 and Pb 208 targets leading to isobaric analog states. (A.C.)

  7. Preequilibrium Nuclear Reactions

    International Nuclear Information System (INIS)

    Strohmaier, B.

    1988-01-01

    After a survey on existing experimental data on precompound reactions and a description of preequilibrium reactions, theoretical models and quantum mechanical theories of preequilibrium emission are presented. The 25 papers of this meeting are analyzed separately

  8. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  9. Oral Hypersensitivity Reactions

    Science.gov (United States)

    ... such as cinnamon, peppermint, eugenol and menthol. Even dental floss and denture cleansers may contain ingredients known to cause a hypersensitivity reaction. Q: How can dental treatment trigger a hypersensitivity reaction? A: Some dental ...

  10. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  11. Polyaniline as a cathode for O/sub 2/ reduction - kinetics of the reaction with H/sub 2/O/sub 2/ and use of the polymer in a model H/sub 2/O/sub 2/ fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Doubova, L.; Mengoli, G.; Musiani, M.M.; Valcher, S.

    1989-03-01

    Oxygen reduction at a polyaniline cathode occurs in aqueous sulfuric acid through a chemical-electrochemical route which involves the intermediate oxidation of leucoemeraldine to emeraldine with the formation of H/sub 2/O/sub 2/. This paper specifically deals with the conversion of leucoemeraldine to emeraldine by H/sub 2/O/sub 2/ whose kinetics, apparently second order on the charge exchange, are similar to those found for the reaction with O/sub 2/, although they occur at lower rate. The catalytic four electron O/sub 2/ reduction mediated by the Fe(III)/Fe(II) couple which decomposes H/sub 2/O/sub 2/ is not fully achieved. However, polyaniline proved to be a reliable cathode for O/sub 2/, sustaining the working of a model H/sub 2//O/sub 2/ fuel cell.

  12. Thermonuclear reaction rates. III

    International Nuclear Information System (INIS)

    Harris, M.J.; Fowler, W.A.; Caughlan, G.R.; Zimmerman, B.A.

    1983-01-01

    Stellar thermonuclear reaction rates are revised and updated, adding a number of new important reaction rates. Several reactions with large negative Q-values are included, and examples of them are discussed. The importance of the decay rates for Mg-26(p,n) exp 26 Al and Al-26(n,p) exp 26 Mg for stellar studies is emphasized. 19 references

  13. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... advancements in the area of (α, 2α) reactions and heavy cluster knockout reactions are discussed. Importance of the finite-range vertex and the final-state interactions are brought out. Keywords. Cluster knockout reactions; FR-DWIA calculations; t-matrix effective interaction. PACS Nos 14.20.Pt; 24.10.

  14. ORGANIC REACTION MECHANISM CONTROVERSY ...

    African Journals Online (AJOL)

    Preferred Customer

    However, there are so many chemical reactions notably in organic chemistry where reactions may not directly lead to products. ... There are concepts that support these ideas but can they be proven to the ... Reaction mechanism is one such issue in organic chemistry that has attracted a lot of controversial comments from ...

  15. Maillard Reaction: review

    Directory of Open Access Journals (Sweden)

    Júlia d'Almeida Francisquini

    2017-11-01

    Full Text Available Maillard reaction is an important subject of study in food science and technology and different areas of knowledge are involved such as chemistry, food engineering, nutrition and food technology. The objective of this paper is to present the basic concepts of the Maillard reaction, such as the reaction stages, the main compounds producced and some technological consequences for dairy products.

  16. Resonant thermonuclear reaction rate

    International Nuclear Information System (INIS)

    Haubold, H.J.; Mathai, A.M.

    1986-01-01

    Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms

  17. Nuclear reaction studies

    International Nuclear Information System (INIS)

    Alexander, J.M.; Lacey, R.A.

    1994-01-01

    Research focused on the statistical and dynamical properties of ''hot'' nuclei formed in symmetric heavy-ion reactions. Theses included ''flow'' measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study 40 Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs

  18. Sleeve reaction chamber system

    Science.gov (United States)

    Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  19. Sodium-concrete reactions

    International Nuclear Information System (INIS)

    Gadd, P.G.

    1982-09-01

    Reaction products of all the major constituents of commercial concrete with liquid sodium have been identified using X-Ray Powder Diffraction. Eight different aggregate materials were chosen to represent the main rock classes available and Ordinary Portland Cement was used throughout. A Differential Thermal Analysis apparatus which enabled continuous stirring of the reactants was designed to improve contact between the powdered concrete components and the liquid sodium. Heats of reaction were calculated from peak areas, the apparatus having been calibrated using reactions of sodium with simple binary oxides whose heats of reaction were known. The heat evolution from aggregates was rationalised on the basis of their mineralogical composition, thus providing a means of choosing an optimum aggregate for use in the concrete of a LMFBR. The reaction of SiO 2 with liquid sodium was shown to depend on the oxygen concentration of the sodium. Reaction products are identified. The reaction of Al 2 O 3 with sodium has been shown also to depend on the oxygen concentration. Reaction products are identified. The evolution of hydrogen during a sodium-cement reaction has been studied using an electrochemical hydrogen meter and the penetration of the liquid metal into cement blocks was also investigated. (author)

  20. Tattoo reaction: Case series

    Directory of Open Access Journals (Sweden)

    Muneer Mohamed

    2018-04-01

    Full Text Available Tattoo is going to be a very common practice especially among young people and we are witnessing a gradual increase of numerous potential complications to tattoo placement which are often seen by physicians, but generally unknown to the public. The most common skin reactions to tattoo include a transient acute inflammatory reaction due to trauma of the skin with needles and medical complications such as superficial and deep local infections, systemic infections, allergic contact dermatitis, photodermatitis, granulomatous and lichenoid reactions, and skin diseases localized on tattooed area (eczema, psoriasis, lichen, and morphea. In this series we present three cases of tattoo reaction.

  1. Clock Reaction: Outreach Attraction

    Science.gov (United States)

    Carpenter, Yuen-ying; Phillips, Heather A.; Jakubinek, Michael B.

    2010-01-01

    Chemistry students are often introduced to the concept of reaction rates through demonstrations or laboratory activities involving the well-known iodine clock reaction. For example, a laboratory experiment involving thiosulfate as an iodine scavenger is part of the first-year general chemistry laboratory curriculum at Dalhousie University. With…

  2. Nuclear Reaction Data Centers

    International Nuclear Information System (INIS)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

  3. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  4. Applications of Reaction Rate

    Science.gov (United States)

    Cunningham, Kevin

    2007-01-01

    This article presents an assignment in which students are to research and report on a chemical reaction whose increased or decreased rate is of practical importance. Specifically, students are asked to represent the reaction they have chosen with an acceptable chemical equation, identify a factor that influences its rate and explain how and why it…

  5. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  6. Allergic reactions during anesthesia.

    Science.gov (United States)

    Levy, J H

    1988-01-01

    Any drug or blood product administered in the perioperative period has the potential to produce a life-threatening allergic (immune reaction) called anaphylaxis. Anaphylactic reactions represent adverse reactions mediated by immunospecific antibodies (IgE and IgG) that interact with mast cells, basophils, or the complement system to liberate vasoactive mediators and recruit other inflammatory cells. Activation of humoral and cellular pathways produces characteristic responses in the respiratory (bronchospasm and upper airway edema), cardiovascular (vasodilation and increased capillary permeability), and cutaneous systems (wheal and flare). Other predictable adverse drug reactions may mimic anaphylaxis to produce similar physiologic consequences independent of allergy (immune responses). Rapid and timely cardiopulmonary intervention with airway maintenance, epinephrine, and volume expansion is essential to avoid an adverse outcome. Severe reactions may be protracted, especially during anesthesia, requiring even larger doses of catecholamines and intensive care observation.

  7. Enhancing chemical reactions

    Science.gov (United States)

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  8. Respiratory transfusion reactions

    Directory of Open Access Journals (Sweden)

    Ivica Marić

    2017-11-01

    Full Text Available Respiratory transfusion-related reactions are not very frequent, partly also because recognition and reporting transfusion reactions is still underemphasized. Tis article describes the most important respiratory transfusion reactions, their pathophysiology, clinical picture and treatment strategies. Respiratory transfusion related reactions can be primary or secondary. The most important primary transfusion-related reactions are TRALI - transfusion-related acute lung injury, TACO – transfusion-associated circulatory overload, and TAD - transfusion-associated dyspnea. TRALI is immuneassociated injury of alveolar basal membrane, which becomes highly permeable and causes noncardiogenic pulmonary edema. Treatment of TRALI is mainly supportive with oxygen, fluids (in case of hypotension and in cases of severe acute respiratory failure also mechanic ventilation. TACO is caused by volume overload in predisposed individuals, such as patients with heart failure, the elderly, infants, patients with anemia and patients with positive fluid balance. Clinical picture is that of a typical pulmonary cardiogenic edema, and the therapy is classical: oxygen and diuretics, and in severe cases also non-invasive or invasive mechanical ventilation. TAD is usually a mild reaction of unknown cause and cannot be classified as TACO or TRALI, nor can it be ascribed to patient’s preexisting diseases. Although the transfusion-related reactions are not very common, knowledge about them can prevent serious consequences. On the one hand preventive measures should be sought, and on the other early recognition is beneficial, so that proper treatment can take place.

  9. The Reaction Wheel Pendulum

    CERN Document Server

    Block, Daniel J; Spong, Mark W

    2007-01-01

    This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, t

  10. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  11. Charge exchange studies with Gold ions at the Brookhaven Booster and AGS

    International Nuclear Information System (INIS)

    Ahrens, L.A.; Hseuh, H.C.; Roser, T.

    1994-01-01

    Efficient acceleration of Gold ions to ll GeV/nucleon places strong constraints on the vacuum and also on the choice of thickness and material of the necessary stripping foils. Results of a number of detailed experimental studies performed with the Gold beam at the Brookhaven Booster and AGS to determine the relevant electron stripping and pick-up probabilities are presented. Of particular interest is the lifetime of the relatively low energy, partially stripped Gold beam in the Booster and the stripping efficiency to Helium-like AU +77 for injection into the AGS

  12. Δ33 resonance in pion nucleus elastic, single, and double charge exchange scattering

    International Nuclear Information System (INIS)

    Johnson, M.B.

    1983-01-01

    The Δ 33 resonance is strongly excited in pion-nucleon scattering, but there is clearly only a limited amount of information that can be learned in scattering the pion from an isolated nucleon. One learns that there is a resonance of mass 1232 MeV, width 115 MeV, and, if one is willing to introduce a dynamical model, something about the off-shell extension of the amplitude. One stands to learn much more from pion-nucleus scattering because in this case the Δ 33 resonance has an opportunity to scatter from nucleons, and how this occurs is not well understood. What do we know about the Δ-N interaction for pion-nucleus scattering. The isobar-hole model was invented to deal directly with the Δ 33 -nucleus dynamics, and a phenomenological determination of the isobar shell-model potential was attempted. The unknown dynamics deltaU/sub Δ/ is contained in a central isoscalar spreading potential of strength W 0 and a spin orbit potential deltaU 0 = W 0 rho + spin-orbit. The real part of W 0 rho is measured relative to the nucleon-nucleus potential. From a more theoretical point of view, one would like to be able to calculate deltaU/sub Δ/, including its isospin dependence, from an underlying dynamical model which is formulated in terms of the basic effective meson-baryon couplings. Some salient properties of these couplings can be determined from models of quark-bag structure, which raises the exciting possibility of learning about these fundamental issues from pion scattering. Attempts at Los Alamos to build a theoretical framework to deal with these and other issues are described

  13. Momentum losses by charge exchange with neutral particles in H-mode discharges at JET

    NARCIS (Netherlands)

    Versloot, T. W.; de Vries, P. C.; Giroud, C.; Brix, M.; von Hellermann, M. G.; Lomas, P. J.; Moulton, D.; Mullane, M. O.; Nunes, I. M.; Salmi, A.; Tala, T.; Voitsekhovitch, I.; Zastrow, K. D.

    2011-01-01

    The effect of a neutral density background on the toroidal angular momentum and kinetic energy profiles has been investigated in JET. Under equivalent conditions but with increasing gas fuelling during the flat top phase, it has been observed that both the edge rotation and temperature decrease. The

  14. The First Wide-field X-ray Imaging Telescope for Observations of Charge Exchange

    Data.gov (United States)

    National Aeronautics and Space Administration — Soft x-ray emission from the interaction of solar wind with the earth's exosphere provides a very significant foreground to all soft x-ray observations. It is...

  15. Theoretical research on charge exchange of uranum ions at thermal energies

    International Nuclear Information System (INIS)

    Bardsley, J.N.

    1975-01-01

    The cross section for resonant charge transfer in U + -U collisions is calculated as a function of the energy in the center-of-mass coordinate frame. The computed value decreases monotonically from approximately 300 A 2 at 0.025 eV to 100 A 2 at 50 eV. The latter value would be appropriate for ions of energy 100 eV moving through a gas of neutral atoms at thermal velocities

  16. Development of polarized negative hydrogen ion source with resonant charge-exchange plasma ionizer

    Science.gov (United States)

    Belov, A. S.; Esin, S. K.; Netchaeva, L. P.; Turbabin, A. V.; Vasil'Ev, G. A.

    2001-06-01

    Polarized negative hydrogen ion beam with peak current of 2.5 mA has been obtained from an atomic beam-type polarized ion source of Institute for Nuclear Research, Moscow. The intensity improvement has been achieved due to increase of efficiency of conversion of polarized hydrogen atoms into polarized negative ions. New converter for production of deuterium plasma with high density of unpolarized negative ions is described. Limitations of the method and possible improvements are discussed. .

  17. Excited state populations and charge-exchange of fast ions in solids

    International Nuclear Information System (INIS)

    Miller, P.D.; Sofield, C.J.; Woods, C.J.

    1984-01-01

    Excited state populations and charge state fractions of 445 MeV Cl ions have been measured for a range of thicknesses of solid C targets. Cross sections for electron capture, loss, excitation and excited state quenching have been determined and these data are found to predict a quantitative difference between equilibrium charge state distributions from gases and solids for a special case of the Bohr-Lindhard density effect model. 8 references, 1 figure, 1 table

  18. Solar Wind Charge Exchange Contribution To The ROSAT Sky Survey Maps

    Science.gov (United States)

    Uprety, Y.; Chiao, M.; Collier, M. R.; Cravens, T.; Galeazzi, M.; Koutroumpa, D.; Kuntz, K. D.; Lallement, R.; Lepri, S. T.; Liu, W.; hide

    2016-01-01

    DXL (Diffuse X-ray emission from the Local Galaxy) is a sounding rocket mission designed to estimate the contribution of solar wind charge eXchange (SWCX) to the diffuse X-ray background and to help determine the properties of the Local Hot Bubble. The detectors are large area thin-window proportional counters with a spectral response that is similar to that of the PSPC (Position Sensitive Proportional Counters) used in the ROSAT All Sky Survey (RASS). A direct comparison of DXL and RASS data for the same part of the sky viewed from quite different vantage points in the solar system, and the assumption of approximate isotropy for the solar wind, allowed us to quantify the SWCX contribution to all six RASS bands (R1-R7, excluding R3). We find that the SWCX contribution at l = 140 degrees, b = 0 degrees, where the DXL path crosses the Galactic plane, is 33 percent plus or minus 6 percent (statistical) plus or minus 12 percent (systematic) for R1, 44 percent plus or minus 6 percent plus or minus 5 percent for R2, 18 percent plus or minus 12 percent plus or minus 11 percent for R4, 14 percent plus or minus 11 percent plus or minus 9 percent for R5, and negligible for the R6 and R7 bands. Reliable models for the distribution of neutral H and He in the solar system permit estimation of the contribution of interplanetary SWCX emission over the the whole sky and correction of the RASS maps. We find that the average SWCX contribution in the whole sky is 26 percent plus or minus 6 percent plus or minus 13 percent for R1, 30 percent plus or minus 4 percent plus or minus 4 percent for R2, 8 percent plus or minus 5 percent plus or minus 5 percent for R4, 6 percent plus or minus 4 percent plus or minus 4 percent for R5, and negligible for R6 and R7.

  19. CXSFIT Code Application to Process Charge-Exchange Recombination Spectroscopy Data at the T-10 Tokamak

    Science.gov (United States)

    Serov, S. V.; Tugarinov, S. N.; Klyuchnikov, L. A.; Krupin, V. A.; von Hellermann, M.

    2017-12-01

    The applicability of the CXSFIT code to process experimental data from Charge-eXchange Recombination Spectroscopy (CXRS) diagnostics at the T-10 tokamak is studied with a view to its further use for processing experimental data at the ITER facility. The design and operating principle of the CXRS diagnostics are described. The main methods for processing the CXRS spectra of the 5291-Å line of C5+ ions at the T-10 tokamak (with and without subtraction of parasitic emission from the edge plasma) are analyzed. The method of averaging the CXRS spectra over several shots, which is used at the T-10 tokamak to increase the signal-to-noise ratio, is described. The approximation of the spectrum by a set of Gaussian components is used to identify the active CXRS line in the measured spectrum. Using the CXSFIT code, the ion temperature in ohmic discharges and discharges with auxiliary electron cyclotron resonance heating (ECRH) at the T-10 tokamak is calculated from the CXRS spectra of the 5291-Å line. The time behavior of the ion temperature profile in different ohmic heating modes is studied. The temperature profile dependence on the ECRH power is measured, and the dynamics of ECR removal of carbon nuclei from the T-10 plasma is described. Experimental data from the CXRS diagnostics at T-10 substantially contribute to the implementation of physical programs of studies on heat and particle transport in tokamak plasmas and investigation of geodesic acoustic mode properties.

  20. Time-of-flight analysis of charge-exchange neutral particles from the TORTUR II plasma

    International Nuclear Information System (INIS)

    Brocken, H.J.B.M.

    1981-10-01

    A disc chopper for time-of-flight analysis of fast neutral particles was constructed for the determination of the ion energy spectrum at lower energies than can be obtained by conventional electro-magnetic analyzers. The method has been applied to the TORTUR II tokamak. The chopper and detection system are described and the measurements are presented. For the interpretation of the results of the measurements a data analysis procedure was developed. The influence of reflections of neutrals at the liner wall showed to be important in the calculations of the neutral density profile at the plasma edge. The neutral energy spectrum in the lower energy range is strongly pronounced by this effect

  1. Experimental study of the production of negative deuterons by double charge-exchange in xenon

    International Nuclear Information System (INIS)

    Bliman, S.; Dousson, S.; Geller, R.; Jacquot, B.; Jacquot, C.; Tsekeris, J.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

    1979-01-01

    It is thought that additional heating of fusion plasma will result from D 0 energetic beam injection in large plasma devices. Due to the fact that the conversion rate D + to D 0 rapidly decreases at high energies, it seems that an interesting way to get these high energy neutrals should be: conversion of D + to D - , acceleration of D - and further neutralization of D - to have D 0 at the desired energy. The efficiency of D + to D - and D 2 + to D - conversion at low energies have been sdudied on a Xe gas target: it appears that D - /D + conversion efficiency shows a smooth variation peaking slightly at 5% for a D + energy of 5 keV. D - /D 2 + increases up to 4% at 12 keV and then decreases. It is shown that the agreement between sample calculation results and experimental values is quite fair for D - /D + [fr

  2. Impurity line emission due to thermal charge exchange in JET edge plasmas

    International Nuclear Information System (INIS)

    Maggi, C.F.; Horton, L.D.; Koenig, R.; Stamp, M.

    1994-01-01

    High n-shell emission from hydrogen-like carbon (C VI, n=8-7) has been routinely observed from the plasma edge of JET. By comparing the measured spectral line intensities with the signals predicted by advanced atomic physics modelling of carbon and hydrogen radiation, integrated with modelling of the divertor and edge plasma, it is concluded that charge transfer from excited state hydrogen donors into fully stripped carbon ions can account for the observed spectral emission, but that the hydrogen distribution and to a lesser extent the carbon distribution away from the strike zone predicted by the transport model are too low. Data presented are those of three upper X-point discharges, where the target material was carbon. 5 refs., 1 fig., 3 tabs

  3. High-energy-ion depletion in the charge exchange spectrum of Alcator C

    International Nuclear Information System (INIS)

    Schissel, D.P.

    1982-01-01

    A three-dimensional, guiding center, Monte Carlo code is developed to study ion orbits in Alcator C. The highly peaked ripple of the magnetic field of Alcator is represented by an analytical expression for the vector potential. The analytical ripple field is compared to the resulting magnetic field generated by a current model of the toroidal plates; agreement is excellent. Ion-Ion scattering is simulated by a pitch angle and an energy scattering operator. The equations of motion are integrated with a variable time step, extrapolating integrator. The code produces collisionless banana and ripple trapped loss cones which agree well with present theory. Global energy distributions have been calculated and show a slight depletion above 8.5 keV. Particles which are ripple trapped and lost are at energies below where depletion is observed. It is found that ions pitch angle scatter less as energy is increased. The result is that, when viewed in velocity space, ions form probability lobes the shape of mouse ears which are fat near the thermal energy. Therefore, particles enter the loss cone at low energies near the bottom of the core. Recommendations for future work include improving the analytic model of the ripple field, testing the effect of del . B not equal to 0 on ion orbits, and improving the efficiency of the code by either using a spline fit for the magnetic fields or by creating a vectorized Monte Carlo code

  4. Cometary X-rays : solar wind charge exchange in cometary atmospheres

    NARCIS (Netherlands)

    Bodewits, Dennis

    2007-01-01

    The interaction of the solar wind with the planets and the interstellar medium is of key importance for the evolution of our solar system. The interaction with Earth's atmosphere is best known for the northern light. In case of Mars, the interaction with the solar wind might have lead to the erosion

  5. High-speed correction factor to the O+-O resonance charge exchange collision frequency

    Directory of Open Access Journals (Sweden)

    K. Omidvar

    1995-03-01

    Full Text Available The high-speed correction factor to the O+-O collision frequency, resulting from drift velocities between ions and neutrals, is calculated by solving the integral expression in this factor both numerically and analytically. Although the analytic solution is valid for either small or large drift velocities between ions and neutrals, for temperatures of interest and all drift velocities considered, agreement is found between analytic and detailed numerical integration results within less than 1% error. Let Tr designate the average of the ion and neutral temperatures in K, and u=vd/α, where vd is the relative drift velocity in cm s-1, and α=4.56×103√Tr cm s-1 is the thermal velocity of the O+-O system. Then, as u ranges from 0 to 2, the correction factor multiplying the collision frequency increases monotonically from 1 to about 1.5. An interesting result emerging from this calculation is that the correction factor for temperatures of aeronomical interest is to a good approximation independent of the temperature, depending only on the scaled velocity u.

  6. Impurity line emission due to thermal charge exchange in JET edge plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Maggi, C.F.; Horton, L.D.; Koenig, R.; Stamp, M. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Summers, H.P. [Strathclyde Univ., Glasgow (United Kingdom)

    1994-07-01

    High n-shell emission from hydrogen-like carbon (C VI, n=8-7) has been routinely observed from the plasma edge of JET. By comparing the measured spectral line intensities with the signals predicted by advanced atomic physics modelling of carbon and hydrogen radiation, integrated with modelling of the divertor and edge plasma, it is concluded that charge transfer from excited state hydrogen donors into fully stripped carbon ions can account for the observed spectral emission, but that the hydrogen distribution and to a lesser extent the carbon distribution away from the strike zone predicted by the transport model are too low. Data presented are those of three upper X-point discharges, where the target material was carbon. 5 refs., 1 fig., 3 tabs.

  7. Shape of the Hα emission line in non resonant charge exchange in hydrogen plasmas

    International Nuclear Information System (INIS)

    Susino Bueno, A.; Zurro Hernandez, B.

    1977-01-01

    The Hα line shape emitted from a maxwellian hydrogen plasma and produced by non resonant change exchange has been calculated. Its explicit shape depends on the ion temperature, on background neutral energy and on the relative shape of the collision cross section. A comparison between theoretical and experimental shapes of the Hα line is carried out to check the model and to deduce the ion plasma temperature. (author) [es

  8. Wide-view charge exchange recombination spectroscopy diagnostic for Alcator C-Moda)

    Science.gov (United States)

    Rowan, W. L.; Bespamyatnov, I. O.; Granetz, R. S.

    2008-10-01

    This diagnostic measures temperature, density, and rotation for the fully stripped boron ion between the pedestal top and the plasma core with resolution consistent with the profile gradients. The diagnostic neutral beam used for the measurements generates a 50 keV, 6 A hydrogen beam. The optical systems provide views in both poloidal and toroidal directions. The imaging spectrometer is optimized to simultaneously accept 45 views as input with minimum cross-talk. In situ calibration techniques are applied for spatial location, spectral intensity, and wavelength. In the analysis, measured spectra are fitted to a model constructed from a detailed description of the emission physics. Methods for removal of interfering spectra are included. Applications include impurity and thermal transport.

  9. Reactor for exothermic reactions

    Science.gov (United States)

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1993-03-02

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  10. Bad Reaction to Cosmetics?

    Science.gov (United States)

    ... Consumers Protect Yourself Health Fraud Bad Reactions to Cosmetics? Tell FDA! Share Tweet Linkedin Pin it More ... Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products

  11. Transfusion reaction - hemolytic

    Science.gov (United States)

    ... Names Blood transfusion reaction Images Surface proteins causing rejection References Choate JD, Maitta RW, Tormey CA, Wu ... PA: Elsevier Saunders; 2016:chap 177. Hall JE. Blood types; transfusion; tissue and organ transplantation. In: Hall JE, ...

  12. Reaction Qualifications Revisited

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2009-01-01

    to a person's effectiveness by causing a favourable reaction in customers, co-workers etc. (for short: recipients) - are involved, this assumption is false. Building on work by Wertheimer, Mason, and Miller, this paper proposes an account of the reaction qualifications that count, from the point of view...... preferences, recipients should not respond to the applicant actually hired on the basis of their (the recipients') racial preferences. My account decomposes the meritocratic ideal into four separate norms, one of which applies to recipients rather than to selectors. Finally, it defends the view that reaction...... qualifications based on antimeritocratic reactions, while not unproblematic, are not entirely irrelevant from the point of view of merit. Notably, selectors need not discount them when no one - including the targets of the objectionable preferences - is unfairly disadvantaged. Because not all problematic...

  13. Sequential charged particle reaction

    International Nuclear Information System (INIS)

    Hori, Jun-ichi; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo

    2004-01-01

    The effective cross sections for producing the sequential reaction products in F82H, pure vanadium and LiF with respect to the 14.9-MeV neutron were obtained and compared with the estimation ones. Since the sequential reactions depend on the secondary charged particles behavior, the effective cross sections are corresponding to the target nuclei and the material composition. The effective cross sections were also estimated by using the EAF-libraries and compared with the experimental ones. There were large discrepancies between estimated and experimental values. Additionally, we showed the contribution of the sequential reaction on the induced activity and dose rate in the boundary region with water. From the present study, it has been clarified that the sequential reactions are of great importance to evaluate the dose rates around the surface of cooling pipe and the activated corrosion products. (author)

  14. Firefighter Nozzle Reaction

    DEFF Research Database (Denmark)

    Chin, Selena K.; Sunderland, Peter B.; Jomaas, Grunde

    2017-01-01

    to anchor forces, the hose becomes straight. The nozzle reaction is found to equal the jet momentum flow rate, and it does not change when an elbow connects the hose to the nozzle. A forward force must be exerted by a firefighter or another anchor that matches the forward force that the jet would exert...... on a perpendicular wall. Three reaction expressions are derived, allowing it to be determined in terms of hose diameter, jet diameter, flow rate, and static pressure upstream of the nozzle. The nozzle reaction predictions used by the fire service are 56% to 90% of those obtained here for typical firefighting hand......Nozzle reaction and hose tension are analyzed using conservation of fluid momentum and assuming steady, inviscid flow and a flexible hose in frictionless contact with the ground. An expression that is independent of the bend angle is derived for the hose tension. If this tension is exceeded owing...

  15. Nucleon induced reactions

    International Nuclear Information System (INIS)

    Gmuca, S.; Antalik, R.; Kristiak, J.

    1988-01-01

    The collection contains full texts of 37 contributions; all fall within the INIS Subject Scope. The topics treated include some unsolved problems of nuclear reactions and relevant problems of nuclear structure at low and intermediate energies. (Z.S.)

  16. Jets in hadronic reactions

    Energy Technology Data Exchange (ETDEWEB)

    Paige, F.E.

    1983-01-01

    Recent experimental data on the properties of jets in hadronic reactions are reviewed and compared with theoretical expectations. Jets are clearly established as the dominant process for high E/sub T/ events in hadronic reactions. The cross section and the other properties of these events are in qualitative and even semiquantitative agreement with expectations based on perturbative QCD. However, we can not yet make precise tests of QCD, primarily because there are substantial uncertainties in the theoretical calculations. 45 references. (WHK)

  17. Oxygen evolution reaction catalysis

    Science.gov (United States)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  18. Anaphylactic reaction to orthoiodohippurate

    Energy Technology Data Exchange (ETDEWEB)

    Stoeckel, M.; Roedbro, P.; Ennow, K.; Kristensen, K.

    1983-02-01

    A case of an anaphylactic reaction following administration of /sup 125/I- and /sup 131/-I-o-iodohippurate in a 32-year-old woman is reported. The patient had a renography performed because of hematuria. She was known to react to an intravenous pyelography previously performed with an anaphylactic shock. The importance of reporting all adverse reactions to radiopharmaceuticals for central registration is stressed.

  19. Adverse drug reactions.

    Science.gov (United States)

    Patton, K; Borshoff, D C

    2018-01-01

    Adverse drug reactions are a cause of significant morbidity and mortality to patients and a source of financial burden to the healthcare system. Of the wide spectrum of adverse drug reactions, the most concerning to the anaesthetist remain anaphylaxis and malignant hyperthermia. Although the incidence of anaphylaxis under anaesthesia is difficult to ascertain, it occurs commonly enough that most anaesthetists will manage at least one case in their career. The wide range of drugs given in the peri-operative period and the variable presentation in the anaesthetised patient can delay diagnosis and treatment, and adversely affect outcome. Furthermore, despite improvements in testing, causative drugs can still be difficult to identify, as adverse reactions may be mediated by mechanisms other than IgE activation. With an increase in the reporting of anaphylaxis to newer anaesthetic drugs such as sugammadex, combined with change over the recent decades in the most likely causative peri-operative agents, it is imperative anaesthetists remain up to date on recent developments. In addition, they should be vigilant to patient characteristics, including pharmacogenetic variations that may predispose to adverse drug reactions, in order to help minimise risks of a reaction. The severity of adverse drug reactions to peri-operative drugs means morbidity and mortality remain high. © 2018 The Association of Anaesthetists of Great Britain and Ireland.

  20. Immediate reaction to clarithromycin.

    Science.gov (United States)

    Gangemi, S; Ricciardi, L; Fedele, R; Isola, S; Purello-D'Ambrosio, F

    2001-01-01

    We present the case of bronchospastic reaction to clarithromycin had during a drug challenge test. Personal allergic history was negative for respiratory allergies and positive for adverse drug reactions to general and regional anesthesia and to ceftriaxone. After the administration of 1/4 of therapeutic dose of clarithromycin the patient showed dyspnea, cough and bronchospasm in all the lung fields. The positivity of the test was confirmed by the negativity to the administration of placebo. The quickness and the clinical characteristic of the adverse reaction suggest a pathogenic mechanism of immediate-type hypersensitivity. On reviewing the literature we have found no reports of bronchospastic reaction to clarithromycin. Macrolides are a class of antibiotics mainly used in the last years in place of beta-lactams because of a broad spectrum of action and a low allergic power. In fact, there are few reports on allergic reactions to these molecules. Clarithromycin is one of the latest macrolides, characterised by the presence of a 14-carbon-atom lactone ring as erythromycin, active on a wide spectrum of pathogens.

  1. Chemical kinetics of gas reactions

    CERN Document Server

    Kondrat'Ev, V N

    2013-01-01

    Chemical Kinetics of Gas Reactions explores the advances in gas kinetics and thermal, photochemical, electrical discharge, and radiation chemical reactions. This book is composed of 10 chapters, and begins with the presentation of general kinetic rules for simple and complex chemical reactions. The next chapters deal with the experimental methods for evaluating chemical reaction mechanisms and some theories of elementary chemical processes. These topics are followed by discussions on certain class of chemical reactions, including unimolecular, bimolecular, and termolecular reactions. The rema

  2. Inflammatory reaction in chondroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, Sigeki [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Sato, Keiji [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Sugiura, Hideshi [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Iwata, Hisashi [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan)

    1996-05-01

    The objective of this study was to evaluate the inflammatory reaction accompanying chondroblastoma and to define the value of the finding in clinical practice. We reviewed the clinical, radiographic, and magnetic resonance (MR) findings in six patients with histologically proven chondroblastoma. In all cases, MR imaging showered marrow and soft tissue edema. In four of six cases, periosteal reaction related to intra-osseous edema was more clearly demonstrated on MR imaging than on radiographs. Follow-up MR studies after surgery were available in three patients and all showed disappearance of inflammatory responses such as marrow and soft tissue edema, and reactive synovitis. We propose that these inflammatory reactions of chondroblastomas are inportant signs for detecting residual tumor in recurrences after surgery, as well as for making a precise diagnosis. The MR changes may also be valuable in demonstrating eradication of the tumor. (orig./MG)

  3. Nanoparticle Reactions on Chip

    Science.gov (United States)

    Köhler, J. M.; Kirner, Th.; Wagner, J.; Csáki, A.; Möller, R.; Fritzsche, W.

    The handling of heterogenous systems in micro reactors is difficult due to their adhesion and transport behaviour. Therefore, the formation of precipitates and gas bubbles has to be avoided in micro reaction technology, in most cases. But, micro channels and other micro reactors offer interesting possibilities for the control of reaction conditions and transport by diffusion and convection due to the laminar flow caused by small Reynolds numbers. This can be used for the preparation and modification of objects, which are much smaller than the cross section of microchannels. The formation of colloidal solutions and the change of surface states of nano particles are two important tasks for the application of chip reactors in nanoparticle technology. Some concepts for the preparation and reaction of nanoparticles in modular chip reactor arrangements will be discussed.

  4. Velocity pump reaction turbine

    Science.gov (United States)

    House, P.A.

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  5. Reactions to dietary tartrazine.

    OpenAIRE

    David, T J

    1987-01-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either ...

  6. Allergic reactions in anaesthesia

    DEFF Research Database (Denmark)

    Krøigaard, M; Garvey, L H; Menné, T

    2005-01-01

    match, the right substance being suspected, but investigations showed an additional allergen or several substances, including the right substance being suspected. CONCLUSIONS: An informed guess is not a reliable way of determining the cause of a supposed allergic reaction during anaesthesia and may put...... a significant number of patients at unnecessary risk. Some patients may be labelled with a wrong allergy, leading to unnecessary warnings against harmless substances, and some patients may be put at risk of subsequent re-exposure to the real allergen. Patients with suspected allergic reactions during...

  7. Introduction to nuclear reactions

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1980-01-01

    This introduction to nuclear reaction phenomena is aimed primarily but not exclusively at readers at the undergraduate student level. An overview of the subject is presented in the first two chapters entitled - Some background information and Introduction to nuclear reactions. The third chapter reviews scattering theory with emphasis on the underlying physical ideas and also provides schematic entrees to the more advanced topics. The physical models which have been developed to account for the various aspects of nuclear phenomena are described in more detail in chapter 4. References and exercises are appended to each chapter. (U.K.)

  8. Modeling of Reaction Calorimeter

    OpenAIRE

    Farzad, Reza

    2014-01-01

    The purpose of this project was to model the reaction calorimeter in order to calculate the heat of absorption which is the most important parameter in this work. Reaction calorimeter is an apparatus which is used in measuring the heat of absorption of CO2 as well as the total pressure in vapor phase based on vapor-liquid equilibrium state. Mixture of monoethanolamine (MEA) and water was used as a solvent to absorb the CO2.Project was divided in to three parts in order to make the programming...

  9. Anniversary reactions in therapists.

    Science.gov (United States)

    Granet, R B; Kalman, T P

    1982-12-01

    The authors provide three case examples of anniversary reactions in psychotherapists evoked in the course of treating patients. They note that psychotherapy has always been discussed in terms of time and phases, which lend themselves to periodicities and may provide the potential for anniversary phenomena. The authors recommend that therapists be aware of such phenomena; monitor their own losses, defenses, and dreams; and continue their own supervision. Possible positive aspects of identification of therapists' anniversary reactions are increased empathy with patients and help in completing unresolved therapeutic and personal issues.

  10. Study of the excited {Delta} resonance ways of decay in {sup 4}He and other nuclei with the ({sup 3}He,T) reaction at 2 GeV; Etude des voies de decroissance de la resonance {Delta} excitee dans l`{sup 4}He et d`autres noyaux par la reaction ({sup 3}He,T) a 2 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Tarle-Rousteau, S.

    1995-05-10

    This thesis describes the ({sup 3}He,t) experiment carried out at 2 GeV at the Saturne National Laboratory (CEA Saclay, France) on {sup 1}H, {sup 2}H, {sup 4}He, {sup 12}C and {sup 208}Pb targets. The charged particles (pions and/or protons) from the {Delta} resonance deexcitation are detected in coincidence with triton using the Diogene large angle detector. New informations are obtained on the ways of {Delta} resonance decay in nuclei. Three modes of decay are investigated: the quasi-free decay, the {Delta}N into NN absorption and the coherent pions production. Modifications of {Delta} resonance properties in nuclei with respect to those of free {Delta} are analysed using the experimental results about pions diffusion, photons absorption, charge exchange reaction and {Delta}-hole model conclusions. The quasi-deuteron absorption process on {sup 4}He is studied using a Monte-Carlo simulation. Coherent pions production is also analysed in detail on {sup 4}He and {sup 12}C target nuclei. The process is very sensitive to {Delta}-hole correlations involved in the longitudinal spin canal which shifts the nucleus response in the {Delta} resonance region towards the low transferred energies. (J.S.). 85 refs., 72 figs., 10 tabs., 1 annexe.

  11. Reaction Decoder Tool (RDT): extracting features from chemical reactions

    OpenAIRE

    Rahman, Syed Asad; Torrance, Gilliean; Baldacci, Lorenzo; Mart?nez Cuesta, Sergio; Fenninger, Franz; Gopal, Nimish; Choudhary, Saket; May, John W.; Holliday, Gemma L.; Steinbeck, Christoph; Thornton, Janet M.

    2016-01-01

    Summary: Extracting chemical features like Atom?Atom Mapping (AAM), Bond Changes (BCs) and Reaction Centres from biochemical reactions helps us understand the chemical composition of enzymatic reactions. Reaction Decoder is a robust command line tool, which performs this task with high accuracy. It supports standard chemical input/output exchange formats i.e. RXN/SMILES, computes AAM, highlights BCs and creates images of the mapped reaction. This aids in the analysis of metabolic pathways and...

  12. Reaction Formulation: A Bibliography.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    Reaction formation was studied by Sigmund Freud. This defense mechanism may be related to repression, substitution, reversal, and compensation (or over-compensation). Alfred Adler considered compensation a basic process in his individual psychology. Anna Freud discussed some defense mechanisms, and Bibring, Dwyer, Huntington, and Valenstein…

  13. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... Cluster knockout reactions are expected to reveal the amount of clustering (such as that of , d and even of heavier clusters such as 12C, 16O etc.) in the target nucleus. In simple terms, incident medium high-energy nuclear projectile interacts strongly with the cluster (present in the target nucleus) as if it ...

  14. Polymerase chain reaction system

    Science.gov (United States)

    Benett, William J.; Richards, James B.; Stratton, Paul L.; Hadley, Dean R.; Milanovich, Fred P.; Belgrader, Phil; Meyer, Peter L.

    2004-03-02

    A portable polymerase chain reaction DNA amplification and detection system includes one or more chamber modules. Each module supports a duplex assay of a biological sample. Each module has two parallel interrogation ports with a linear optical system. The system is capable of being handheld.

  15. Reaction product imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, D.W. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

  16. Explaining competitive reaction effects

    NARCIS (Netherlands)

    Leeflang, P.S.H.; Wittink, D.R.

    Changes in promotional expenditure decisions for a brand, as in other marketing decisions, should be based on the expected impact on purchase and consumption behavior as well as on the likely reactions by competitors. Purchase behavior may be predicted from estimated demand functions. Competitive

  17. Cutaneous adverse drug reactions

    African Journals Online (AJOL)

    limiting but they can be the initial presentation of more serious reactions such as Stevens-Johnson and drug hypersensitivity syndromes.3 It is thus important for the clinician to distinguish between self-limiting morbilliform drug eruptions that resolve solely with the withdrawal of the offending drug and the life-threatening ...

  18. Michaelis–Arbuzov reaction

    Indian Academy of Sciences (India)

    agriculture, medicine and synthetic chemistry as cata- lysts and synthetic ... ophile with an electrophilic carbon2 have been found in many synthetic ... problems. Catalytic methods play a special role in synthetic organic chemistry for progress of the reactions in sim- ple fashion. Therefore, researchers have developed var-.

  19. Managing Your Emotional Reactions

    Science.gov (United States)

    ... this situation: Your friends have received promposals (or college acceptances, team places, etc.). But you haven't. Once you identify, ... each one. Which reaction would lead to the best outcome? We always have a ... that work out well. Learning to react well takes practice. But we all ...

  20. [Allergic reactions during anesthesia].

    Science.gov (United States)

    Escolano, F; Sierra, P

    1996-01-01

    Anaphylactic reaction during anesthesia is a constant source of concern for anesthesiologists, given that the rates of death and serious complications are high and predicting which patients will be susceptible is impossible. All substances used in the perioperative period carry a certain risk of releasing histamine and triggering an allergic reaction, though muscle relaxants are the drugs usually implicated. The incidence of serious anaphylaxis ranges between 1:4,000 and 1:23,000 anesthetic procedures, with mortality set at 3-9% and morbidity 10 times higher. Clinical signs vary from mild symptoms to anaphylactic shock and cardiac arrest. The diagnostic procedure to follow upon observing an allergic reaction is to first identify the responsible mechanism and later the responsible agent, as well as drugs that can be used safely. Prophylaxis is based mainly on recognizing predisposed patients before surgery and following recommendations and pharmacological protocols based on better understanding of the pathophysiological mechanisms that cause anaphylactic reaction and on experience in managing them.

  1. Multicomponent reactions in polymer synthesis.

    Science.gov (United States)

    Kakuchi, Ryohei

    2014-01-03

    More participants, yet efficient reactions: Multicomponent reactions (MCRs) have found application in polymer chemistry both in the synthesis of multifunctional monomers and in post-polymerization modification. Examples include the Passerini three-component reaction, the Ugi four-component reaction, and the copper-catalyzed MCR. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. What Is a Reaction Rate?

    Science.gov (United States)

    Schmitz, Guy

    2005-01-01

    The definition of reaction rate is derived and demonstrations are made for the care to be taken while using the term. Reaction rate can be in terms of a reaction property, the extent of reaction and thus it is possible to give a definition applicable in open and closed systems.

  3. Dynamics of the reaction of the N/sup +/ ion with hydrogen isotopes and helium

    Energy Technology Data Exchange (ETDEWEB)

    Ruska, W.E.W.

    1976-06-28

    Molecular beam techniques were used to study the reactive and non-reactive scattering of the nitrogen positive ion from hydrogen isotopes and helium, at energies above the stability limit for spectator stripping. Reactive scattering was observed from H/sub 2/ and HD targets. Non-reactive scattering was observed from H/sub 2/ and D/sub 2/ targets, and from He at one energy. A correlation diagram for the system is presented and compared with the available a priori calculations. Two surfaces are expected to lead to reaction. One is a /sup 3/A/sub 2/ - /sup 3/PI surface, the other, a /sup 3/B/sub 1/ - /sup 3/..sigma../sup -/ surface. Collinear approaches are expected to be most reactive on the /sup 3/B/sub 1/ - /sup 3/..sigma../sup -/ surface; noncollinear, on the /sup 3/A/sub 1/ - /sup 3/PI surface. Theoretical models are presented in which an incident hard sphere A, representing the projectile ion, strikes one of a pair of hard spheres B-C representing the B hydrogen molecule. After an impulsive A-B collision, an impulsive B-C collision may take place. The relative energy of A to B is then examined, and a reactive event is considered to have occurred if the energy is less than the dissociation energy for the A-B molecule. This model is treated both in the collinear case and in three dimensions. A graphical technique for the collinear case is summarized and applied to reaction on the /sup 3/B/sub 1/ - /sup 3/..sigma../sup -/ surface. An integral equation for the three-dimensional case is developed. A synthesis of two treatments, representing the behavior of the system on both reactive surfaces, and considering the charge-exchange channel, correctly predicts the observed product distribution. Predictions are also presented for the as yet unobserved case of reactive scattering from a D/sub 2/ target.

  4. High-resolution study of Gamow-Teller transitions in the 47Ti(3He,t)47V reaction

    Science.gov (United States)

    Ganioǧlu, E.; Fujita, H.; Fujita, Y.; Adachi, T.; Algora, A.; Csatlós, M.; Deaven, J. M.; Estevez-Aguado, E.; Guess, C. J.; Gulyás, J.; Hatanaka, K.; Hirota, K.; Honma, M.; Ishikawa, D.; Krasznahorkay, A.; Matsubara, H.; Meharchand, R.; Molina, F.; Okamura, H.; Ong, H. J.; Otsuka, T.; Perdikakis, G.; Rubio, B.; Scholl, C.; Shimbara, Y.; Susoy, G.; Suzuki, T.; Tamii, A.; Thies, J. H.; Zegers, R. G. T.; Zenihiro, J.

    2013-01-01

    Given the importance of Gamow-Teller (GT) transitions in nuclear structure and astrophysical nuclear processes, we have studied Tz=+3/2→+1/2, GT transitions starting from the 47Ti nucleus in the (3He,t) charge-exchange reaction at 0∘ and at an intermediate incident energy of 140 MeV/nucleon. The experiments were carried out at the Research Center for Nuclear Physics (RCNP), Osaka, using the high-resolution facility with a high-dispersion beam line and the Grand-Raiden spectrometer. With an energy resolution of 20 keV, individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy (Ex) of 12.5 MeV. The GT strength was widely distributed from low excitation energy up to 12.5 MeV, where we had to stop the analysis because of the high level density. The distribution of the GT strengths was compared with the results of shell model calculations using the GXPF1 interaction. The calculations could reproduce the experimental GT distributions well. The GT transitions from the ground state of 47Ti and the M1 transitions from the isobaric analog state in 47V to the same low-lying states in 47V are analogous. It was found that the ratios of GT transition strengths to the ground state, the 0.088-MeV state, and the 0.146-MeV state are similar to the ratios of the strengths of the analogous M1 transitions from the isobaric analog state (IAS) to these states. The measured distribution of the GT strengths was also compared with those starting from the Tz=+3/2 nucleus 41K to the Tz=+1/2 nucleus 41Ca.

  5. Nuclear reactions in astrophysics

    International Nuclear Information System (INIS)

    Cardenas, M.

    1976-01-01

    It is revised the nuclear reactions which present an interest in astrophysics regarding the explanation of some problems such as the relative quantity of the elements, the structure and evolution of the stars. The principal object of the study is the determination of the experimental possibilities in the field of astrophysics, of an accelerator Van de Graaff's 700 KeV type. Two hundred nuclear reactions approximately, were found, and nothing or very little has been done in the intervals of energy which are of interest. Since the bombardment energies and the involved sections are low in some cases, there are real possibilities, for the largest number of stars to obtain important statistical data with the above mentioned accelerator, taking some necessary precautions. (author)

  6. Reactions to dietary tartrazine.

    Science.gov (United States)

    David, T J

    1987-02-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either by the parents or the nursing staff after the administration of placebo or active substances. Twenty two patients returned to a normal diet without problems, but the parents of two children insisted on continuing the diet. While popular belief has it that additives may have harmful behavioural effects, objective verification is required to prevent overdiagnosis.

  7. Adverse reactions to antidepressants

    DEFF Research Database (Denmark)

    Uher, Rudolf; Farmer, Anne; Henigsberg, Neven

    2009-01-01

    (74%), constipation (33%) and weight gain (15%) were associated with nortriptyline treatment. Diarrhoea (9%), insomnia (36%) and yawning (16%) were more common during treatment with escitalopram. Problems with urination and drowsiness predicted discontinuation of nortriptyline. Diarrhoea and decreased......Background: Adverse drug reactions are important determinants of non-adherence to antidepressant treatment, but their assessment is complicated by overlap with depressive symptoms and lack of reliable self-report measures. Aims: To evaluate a simple self-report measure and describe adverse...... comparing escitalopram and nortriptyline. Results: There was good agreement between self-report and psychiatrists' ratings. Most complaints listed as adverse reactions in people with depression were more common when they were medication-free rather than during their treatment with antidepressants. Dry mouth...

  8. Concordant Chemical Reaction Networks

    Science.gov (United States)

    Shinar, Guy; Feinberg, Martin

    2015-01-01

    We describe a large class of chemical reaction networks, those endowed with a subtle structural property called concordance. We show that the class of concordant networks coincides precisely with the class of networks which, when taken with any weakly monotonic kinetics, invariably give rise to kinetic systems that are injective — a quality that, among other things, precludes the possibility of switch-like transitions between distinct positive steady states. We also provide persistence characteristics of concordant networks, instability implications of discordance, and consequences of stronger variants of concordance. Some of our results are in the spirit of recent ones by Banaji and Craciun, but here we do not require that every species suffer a degradation reaction. This is especially important in studying biochemical networks, for which it is rare to have all species degrade. PMID:22659063

  9. Enzyme catalysed tandem reactions.

    Science.gov (United States)

    Oroz-Guinea, Isabel; García-Junceda, Eduardo

    2013-04-01

    To transfer to the laboratory, the excellent efficiency shown by enzymes in Nature, biocatalysis, had to mimic several synthetic strategies used by the living organisms. Biosynthetic pathways are examples of tandem catalysis and may be assimilated in the biocatalysis field for the use of isolated multi-enzyme systems in the homogeneous phase. The concurrent action of several enzymes that work sequentially presents extraordinary advantages from the synthetic point of view, since it permits a reversible process to become irreversible, to shift the equilibrium reaction in such a way that enantiopure compounds can be obtained from prochiral or racemic substrates, reduce or eliminate problems due to product inhibition or prevent the shortage of substrates by dilution or degradation in the bulk media, etc. In this review we want to illustrate the developments of recent studies involving in vitro multi-enzyme reactions for the synthesis of different classes of organic compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Reactions to dietary tartrazine.

    Science.gov (United States)

    David, T J

    1987-01-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either by the parents or the nursing staff after the administration of placebo or active substances. Twenty two patients returned to a normal diet without problems, but the parents of two children insisted on continuing the diet. While popular belief has it that additives may have harmful behavioural effects, objective verification is required to prevent overdiagnosis. PMID:3548601

  11. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... (figure 2), the corresponding α–α t-matrix effective interactions are seen to be widely different (figure 3). 2. Formalism. The finite-range transition matrix element T n,l. BA in the triple differential cross-section [13], d3σ d 1d 2dE1. = Fkin × Sl × |T n,l. BA (kf 1, kf 2, ki)|2 for the (α, 2α) cluster knockout reactions is ...

  12. Flora rapid reaction forces

    Directory of Open Access Journals (Sweden)

    Виктор Васильевич Туганаев

    2015-10-01

    Full Text Available Flora rapid reaction forces ­– there are explerents that have high productivity and weak competitiveness. Their innately functional allocation is to plant disturbed acres as soon as possible preventing by that biosphere homeostasis disturbance. Disturbed acres were used to take place in geological history. Nowadays they take especially big areas. Considering a historical line of Dactylis glomerata L. authors suggest to separate out an especial group of anthropochores which they call medieophytes

  13. Photochemical reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.C. [Lawrence Berkeley Laboratory, Livermore, CA (United States)

    1993-12-01

    The purpose of the program is to develop a fundamental understanding of unimolecular and bimolecular reaction dynamics with application in combustion and energy systems. The energy dependence in ketene isomerization, ketene dissociation dynamics, and carbonyl substitution on organometallic rhodium complexes in liquid xenon have been studied. Future studies concerning unimolecular processes in ketene as well as energy transfer and kinetic studies of methylene radicals are discussed.

  14. Adverse cutaneous drug reaction

    Directory of Open Access Journals (Sweden)

    Nayak Surajit

    2008-01-01

    Full Text Available In everyday clinical practice, almost all physicians come across many instances of suspected adverse cutaneous drug reactions (ACDR in different forms. Although such cutaneous reactions are common, comprehensive information regarding their incidence, severity and ultimate health effects are often not available as many cases go unreported. It is also a fact that in the present world, almost everyday a new drug enters market; therefore, a chance of a new drug reaction manifesting somewhere in some form in any corner of world is unknown or unreported. Although many a times, presentation is too trivial and benign, the early identification of the condition and identifying the culprit drug and omit it at earliest holds the keystone in management and prevention of a more severe drug rash. Therefore, not only the dermatologists, but all practicing physicians should be familiar with these conditions to diagnose them early and to be prepared to handle them adequately. However, we all know it is most challenging and practically difficult when patient is on multiple medicines because of myriad clinical symptoms, poorly understood multiple mechanisms of drug-host interaction, relative paucity of laboratory testing that is available for any definitive and confirmatory drug-specific testing. Therefore, in practice, the diagnosis of ACDR is purely based on clinical judgment. In this discussion, we will be primarily focusing on pathomechanism and approach to reach a diagnosis, which is the vital pillar to manage any case of ACDR.

  15. Modelling Tethered Enzymatic Reactions

    Science.gov (United States)

    Solis Salas, Citlali; Goyette, Jesse; Coker-Gordon, Nicola; Bridge, Marcus; Isaacson, Samuel; Allard, Jun; Maini, Philip; Dushek, Omer

    Enzymatic reactions are key to cell functioning, and whilst much work has been done in protein interaction in cases where diffusion is possible, interactions of tethered proteins are poorly understood. Yet, because of the large role cell membranes play in enzymatic reactions, several reactions may take place where one of the proteins is bound to a fixed point in space. We develop a model to characterize tethered signalling between the phosphatase SHP-1 interacting with a tethered, phosphorylated protein. We compare our model to experimental data obtained using surface plasmon resonance (SPR). We show that a single SPR experiment recovers 5 independent biophysical/biochemical constants. We also compare the results between a three dimensional model and a two dimensional model. The work gives the opportunity to use known techniques to learn more about signalling processes, and new insights into how enzyme tethering alters cellular signalling. With support from the Mexican Council for Science and Technology (CONACyT), the Public Education Secretariat (SEP), and the Mexican National Autonomous University's Foundation (Fundacion UNAM).

  16. Polyneutron Chain Reactions

    International Nuclear Information System (INIS)

    John C. Fisher

    2000-01-01

    Although helium atoms do not form molecules, a sufficiently large number will bind into a stable liquid droplet. A comparable situation is expected for neutrons, with a sufficiently large number binding into a stable droplet of neutron matter. Such polyneutron droplets can be viewed as isotopes of an element with nuclear charge Z=0, tentatively denoted neutrium, symbol Nt. Because of the relatively weak binding of neutrons compared with that of a mix of neutrons and protons, the minimum number of neutrons required for stability of a droplet is fairly large. Early estimates of ∼60 may be reduced to a dozen or so by the BCS pairing interaction. The Nt entries with N≥12 are new to the table of isotopes. Because all of them are beta-unstable, none is expected to persist as a free particle. Yet, some may occasionally be produced by means to be described below, and it is of interest to examine their decay chains and their interactions with charged nuclei to ascertain how their presence might be revealed. Although these reactions are interesting, they cannot be taken seriously without identifying a source for the initial Nt isotope that begins the chain. Here, we consider possible interactions between 16 O and A Nt. Although there is no strong interaction between them, we can expect a very weak residual attraction that can form a loosely bound 16 O A Nt nuclear molecule. This is not a compound nucleus in the usual sense because, considered as fluids, the 16 O and A Nt droplets are immiscible. For a droplet with fewer than about 60 neutrons, beta decay of A Nt is prevented by the buildup of Coulomb energy associated with transforming A Nt into A H in close proximity to 16 O. Thus, it is possible that 16 O A Nt molecules can persist indefinitely and that a few of them may be present in ordinary water as supermassive oxygen nuclei. Because the binding of these molecules is weak, the A Nt component can tunnel to an adjacent nucleus, and if the adjacent nucleus is 18 O, a

  17. Boron atom reactions

    International Nuclear Information System (INIS)

    Estes, R.; Tabacco, M.B.; Digiuseppe, T.G.; Davidovits, P.

    1982-01-01

    The reaction rates of atomic boron with various epoxides have been measured in a flow tube apparatus. The bimolecular rate constants, in units of cm 3 molecule -1 s -1 , are: 1,2-epoxypropane (8.6 x 10 -11 ), 1,2-epoxybutane (8.8 x 10 -11 ), 1,2,3,4-diepoxybutane (5.5 x 10 -11 ), 1-chloro-2,3-epoxypropane (5.7 x 10 -11 ), and 1,2-epoxy-3,3,3-trichloropropane (1.5 x 10 -11 ). (orig.)

  18. Microfluidic polymerase chain reaction

    Science.gov (United States)

    Maltezos, George; Gomez, Alvaro; Zhong, Jiang; Gomez, Frank A.; Scherer, Axel

    2008-12-01

    We implement microfluidic technology to miniaturize a thermal cycling system for amplifying DNA fragments. By using a microfluidic thermal heat exchanger to cool a Peltier junction, we have demonstrated rapid heating and cooling of small volumes of solution. We use a miniature K-type thermocouple to provide a means for in situ sensing of the temperature inside the microrefrigeration system. By combining the thermocouple, two power supplies controlled by a relay system, and computer automation, we reproduce the function of a commercial polymerase chain reaction thermal cycler and demonstrate amplification of a DNA sample of about 1000 base pairs.

  19. Low Energy Nuclear Reactions?

    CERN Multimedia

    CERN. Geneva; Faccini, R.

    2014-01-01

    After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

  20. (d,pγ) Reactions and the surrogate reaction technique

    International Nuclear Information System (INIS)

    Cizewski, J.A.; Hatarik, R.; Jones, K.L.; Pain, S.D.; Thomas, J.S.; Johnson, M.S.; Bardayan, D.W.; Blackmon, J.C.; Smith, M.S.; Kozub, R.L.

    2007-01-01

    Neutron-capture reactions on neutron-rich nuclei are important to understand r-process nucleosynthesis, as well as applied needs such as stewardship science and nuclear energy. Because of the short half-lives of these species, it is not possible to measure these reactions directly with neutron beams on unstable targets. The (d,pγ) reaction with radioactive ion beams has been proposed as a surrogate reaction for (n,γ). Experiments to develop (d,pγ) techniques with radioactive ion beams and to demonstrate the efficacy of the (d,pγ) reaction as a surrogate for (n,γ) are discussed