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.

Coherent single pion production by antineutrino charged current interactions and test of PCAC

Science.gov (United States)

Marage, P.; Aderholz, M.; Allport, P.; Armenise, N.; Baton, J. P.; Berggren, M.; Bertrand, D.; Brisson, V.; Bullock, F. W.; Burkot, W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Gerbier, G.; Guy, J.; Hamisi, F.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Klein, H.; Middleton, R. P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Natali, S.; Neveu, M.; O'Neale, S. W.; Parker, M. A.; Petiau, P.; Sacton, J.; Sansum, R. A.; Simopoulou, E.; Vallée, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wells, J.; Wittek, W.

1986-06-01

The cross section for coherent production of a single π- meson in charged current antineutrino interactions on neon nuclei has been measured in BEBC to be (175±25) 10-40 cm2/neon nucleus, averaged over the energy spectrum of the antineutrino wide band beam at the CERN SPS; this corresponds to (0.9±0.1) % of the total charged currentbar v_μ cross section. The distributions of kinematical variables are in agreement with theoretical predictions based on the PCAC hypothesis and the meson dominance model; in particular, the Q 2 dependence is well described by a propagator containing a mass m=(1.35±0.18) GeV. The absolute value of the cross section is also in agreement with the model. This analysis thus provides a test of the PCAC hypothesis in the antineutrino energy range 5 150 GeV.

Coherent single pion production by antineutrino charged current interactions and test of PCAC

International Nuclear Information System (INIS)

Marage, P.; Bertrand, D.; Sacton, J.; Aderholz, M.; Wittek, W.; Allport, P.; Wells, J.; Baton, J.P.; Gerbier, G.; Neveu, M.; Clayton, E.F.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Cooper-Sarkar, A.M.; Guy, J.; Kasper, P.; Venus, W.; Klein, H.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Simopoulou, E.; Vayaki, A.

1986-01-01

The cross section for coherent production of a single π - meson in charged current antineutrino interactions on neon nuclei has been measured in BEBC to be (175+-25) 10 -40 cm 2 /neon nucleus, averaged over the energy spectrum of the antineutrino wide band beam at the CERN SPS; this corresponds to (0.9+-0.1)% of the total charged current anti νsub(μ) cross section. The distributions of kinematical variables are in agreement with theoretical predictions based on the PCAC hypothesis and the meson dominance model; in particular, the Q 2 dependence is well described by a propagator containing a mass m=(1.35+-0.18)GeV. The absolute value of the cross section is also in agreement with the model. This analysis thus provides a test of the PCAC hypothesis in the antineutrino energy range 5-150 GeV. (orig.)

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.

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

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.

Study of the antineutrino-induced elastic semi-leptonic neutral current reaction

International Nuclear Information System (INIS)

Racca, C.

1978-01-01

A study of the elastic neutral current reaction antiνsub(μ)p→antiνsub(μ)p has been done using Gargamelle filled with propane and the antineutrino beam of the CERN P.S. The space-time structure of the weak neutral current is discussed, the predictions of various V-A models for the ratio of neutral to charged current elastic cross-sections Rsup(antiν) are given. The experimental set-up, the scanning criteria and the program of reconstruction are described. The background due to the contamination by the reaction np→np principally is studied. Cuts are defined to resorbe these backgrounds and corrections are made for other backgrounds and losses. The results are compared with those of the reaction antiνsub(μ)p→μ + n and the ratio Rsup(antiν) is calculated. An upper limit of this ratio is given and the results are discussed [fr

Measurement of the antineutrino to neutrino charged-current interaction cross section ratio in MINERvA

Science.gov (United States)

Ren, L.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Cai, T.; Carneiro, M. F.; da Motta, H.; Devan, J.; Dytman, S. A.; Díaz, G. A.; Eberly, B.; Endress, E.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Golan, T.; Gran, R.; Han, J. Y.; Harris, D. A.; Hurtado, K.; Kiveni, M.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman, Paolone, V.; Park, J.; Patrick, C. E.; Perdue, G. N.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Solano Salinas, C. J.; Sultana, M.; Sánchez Falero, S.; Valencia, E.; Walton, T.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; MinerνA Collaboration

2017-04-01

We present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2-22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a subsample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12-22 GeV. We also report on the antineutrino-neutrino cross section ratio, RCC , which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of ˜5 % at low energy. Our results for the antineutrino-nucleus scattering cross section and for RCC are the most precise to date in the energy range Eν<6 GeV .

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

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.

Observation of coherent diffractive charged current interactions of antineutrinos on neon nuclei

Science.gov (United States)

Marage, P.; Aderholz, M.; Armenise, N.; Azemoon, T.; Barnham, K. W. J.; Bartley, J. H.; Baton, J. P.; Bertrand, D.; Brisson, V.; Bullock, F. W.; Calicchio, M.; Cooper, A. M.; Chwastowski, J.; Clayton, E. F.; Coghen, T.; Erriquez, O.; Fitch, P. J.; Gerbier, G.; Guy, J.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Kochowski, C.; Leighton-Davies, S.; Middleton, R. P.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; Nuzzo, S.; O'Neale, S. W.; Parker, M. A.; Petiau, P.; Ruggieri, F.; Sacton, J.; Sansum, R. A.; Simopoulou, E.; Talebzadeh, M.; Vallee, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wells, J.; Wernhard, K. L.; Wittek, W.; Zevgolatakos, E.; WA59 Collaboration

1984-05-01

First observation is reported of semi-inclusive coherent diffractive charged current interactions of antineutrinos on neon nuclei. A sharp peaking towards zero is observed in the | t| distribution of interactions for which the final state charge is 0 and from which only one negative hadron is emitted, unaccompanied by any evidence of nuclear fragmentation or reinteraction. This peak is correlated with high momentum of the outgoing charged hadron and with small values of Q2 and x.

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

Observation of coherent diffractive charged current interactions of antineutrino on neon nuclei

International Nuclear Information System (INIS)

Marage, P.; Sacton, J.; Bertrand, D.; Aderholz, M.; Wernhard, K.L.; Wittek, W.; Armenise, N.; Calicchio, M.; Erriquez, O.; Nuzzo, S.; Ruggieri, F.; Azemoon, T.; Bartley, J.H.; Bullock, F.W.; Fitch, P.J.; Leighton-Davies, S.; Sansum, R.A.; Baton, J.P.; Gerbier, G.; Kochowski, C.; Neveu, M.; Brisson, V.; Petiau, P.; Vallee, C.; Chwastowski, J.; Coghen, T.; Guy, J.; Kasper, P.; Venus, W.; Simopoulou, E.; Vayaki, A.; Zevgolatakos, E.; Varvell, K.; Wells, J.

1984-01-01

First observation is reported of semi-inclusive coherent diffractive charged current interactions of antineutrinos on neon nuclei. A sharp peaking towards zero is observed in the vertical stroketvertical stroke distribution of interactions for which the final state charge is 0 and from which only one negative hadron is emitted, unaccompanied by any evidence of nuclear fragmentation or reinteraction. This peak is correlated with high momentum of the outgoing charged hadron and with small values of Q 2 and chi. (orig.)

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.

The loss rates of O+ in the inner magnetosphere caused by both magnetic field line curvature scattering and charge exchange reactions

Science.gov (United States)

Ji, Y.; Shen, C.

2014-03-01

With consideration of magnetic field line curvature (FLC) pitch angle scattering and charge exchange reactions, the O+ (>300 keV) in the inner magnetosphere loss rates are investigated by using an eigenfunction analysis. The FLC scattering provides a mechanism for the ring current O+ to enter the loss cone and influence the loss rates caused by charge exchange reactions. Assuming that the pitch angle change is small for each scattering event, the diffusion equation including a charge exchange term is constructed and solved; the eigenvalues of the equation are identified. The resultant loss rates of O+ are approximately equal to the linear superposition of the loss rate without considering the charge exchange reactions and the loss rate associated with charge exchange reactions alone. The loss time is consistent with the observations from the early recovery phases of magnetic storms.

Double Charge Exchange Reactions and Double Beta Decay

Science.gov (United States)

Auerbach, N.

2018-05-01

The subject of this presentation is at the forefront of nuclear physics, namely double beta decay. In particular one is most interested in the neutrinoless process of double beta decay, when the decay proceeds without the emission of two neutrinos. The observation of such decay would mean that the lepton conservation symmetry is violated and that the neutrinos are of Majorana type, meaning that they are their own anti-particles. The life time of this process has two unknowns, the mass of the neutrino and the nuclear matrix element. Determining the nuclear matrix element and knowing the cross-section well will set limits on the neutrino mass. There is a concentrated effort among the nuclear physics community to calculate this matrix element. Usually these matrix elements are a very small part of the total strength of the transition operators involved in the process. There is no simple way to “calibrate” the nuclear double beta decay matrix element. The double beta decay is a double charge exchange process, therefore it is proposed that double charge exchange reactions using ion projectiles on nuclei that are candidates for double beta decay, will provide additional necessary information about the nuclear matrix elements.

Momentum transfer in relativistic heavy ion charge-exchange reactions

Science.gov (United States)

Townsend, L. W.; Wilson, J. W.; Khan, F.; Khandelwal, G. S.

1991-01-01

Relativistic heavy ion charge-exchange reactions yield fragments (Delta-Z = + 1) whose longitudinal momentum distributions are downshifted by larger values than those associated with the remaining fragments (Delta-Z = 1, -2,...). Kinematics alone cannot account for the observed downshifts; therefore, an additional contribution from collision dynamics must be included. In this work, an optical model description of collision momentum transfer is used to estimate the additional dynamical momentum downshift. Good agreement between theoretical estimates and experimental data is obtained.

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

The loss rates of O{sup +} in the inner magnetosphere caused by both magnetic field line curvature scattering and charge exchange reactions

Energy Technology Data Exchange (ETDEWEB)

Ji, Y., E-mail: yji@spaceweather.ac.cn [State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China); College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049 (China); Shen, C. [State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)

2014-03-15

With consideration of magnetic field line curvature (FLC) pitch angle scattering and charge exchange reactions, the O{sup +} (>300 keV) in the inner magnetosphere loss rates are investigated by using an eigenfunction analysis. The FLC scattering provides a mechanism for the ring current O{sup +} to enter the loss cone and influence the loss rates caused by charge exchange reactions. Assuming that the pitch angle change is small for each scattering event, the diffusion equation including a charge exchange term is constructed and solved; the eigenvalues of the equation are identified. The resultant loss rates of O{sup +} are approximately equal to the linear superposition of the loss rate without considering the charge exchange reactions and the loss rate associated with charge exchange reactions alone. The loss time is consistent with the observations from the early recovery phases of magnetic storms.

Charge exchange reactions and solar neutrino detection in 81Br

International Nuclear Information System (INIS)

Liu, K.F.; Gabbard, F.

1983-01-01

The feasibility of 81 Br as the detector of the solar neutrino flux hinges upon the knowledge of the Gamow-Teller matrix element from the ground state of 81 Br to the (5/2) - state at 0.457 MeV in 81 Kr. The possibility of obtaining this matrix element is discussed in terms of the (p,n) and ( 3 He, t) charge exchange reactions. .ID CR2009 .PG 98 112

Neutrino (antineutrino) effective charge in a magnetized electron-positron plasma

International Nuclear Information System (INIS)

Serbeto, A.; Rios, L.A.; Mendonca, J.T.; Shukla, P.K.

2004-01-01

Using dynamical techniques of the plasma physics, the neutrino (antineutrino) effective charge in a magnetized dense electron-positron plasma is determined here. It shown that its value, which is determined by the plasma collective processes, depends mainly on the propagation direction of plasma waves and neutrinos against the external magnetic field direction. The direction dependence of the effective charge occurs due to the fact that the magnetic field breaks the plasma isotropy. The present theory gives a unified picture of the problem which is valid for an external magnetic field below the Landau-Schwinger critical value. Comparison with some of the results from the quantum field theory has been made

Special features of the inverse-beta-decay reaction proceeding on a proton in a reactor-antineutrino flux

Energy Technology Data Exchange (ETDEWEB)

Kopeikin, V. I., E-mail: kopeikin46@yandex.ru; Skorokhvatov, M. D., E-mail: skorokhvatov-md@nrcki.ru [National Research Center Kurchatov Institute (Russian Federation)

2017-03-15

The evolution of the reactor-antineutrino spectrum and the evolution of the spectrum of positrons from the inverse-beta-decay reaction in the course of reactor operation and after reactor shutdown are considered. The present-day status in determining the initial reactor-antineutrino spectrum on the basis of spectra of beta particles from mixtures of products originating from uranium and plutonium fission is described. A local rise of the experimental spectrum of reactor antineutrinos with respect to the expected spectrum is studied.

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.)

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

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.

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.

Neutral strange particle production in antineutrino-neon charged current interactions

Science.gov (United States)

Willocq, S.; Marage, P.; Aderholz, M.; Allport, P.; Baton, J. P.; Berggren, M.; Clayton, E. F.; Cooper-Sarkar, A. M.; Erriquez, O.; Faulkner, P. J. W.; Guy, J.; Hulth, P. O.; Jones, G. T.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; O'Neale, S.; Sacton, J.; Sansum, R. A.; Varvell, K.; Venus, W.; Wells, J.; Wittek, W.

1992-06-01

Neutral strange particle production inbar v Ne charged current interactions is studied using the bubble chamber BEBC, exposed to the CERN SPS antineutrino wide band beam. From a sample of 1191 neutral strange particles, the inclusive production rates are determined to be (15.7±0.8)% for K 0 mesons, (8.2±0.5)% for Λ, (0.4±0.2)% forbar Λ and (0.6±0.3)% for Σ0 hyperons. The inclusive production properties of K 0 mesons and Λ hyperons are investigated. The Λ hyperons are found to be polarized in the production plane.

Nuclear effects in (anti)neutrino charge-current quasielastic scattering at MINER νA kinematics

Science.gov (United States)

Ivanov, M. V.; Antonov, A. N.; Megias, G. D.; González-Jiménez, R.; Barbaro, M. B.; Caballero, J. A.; Donnelly, T. W.; Udías, J. M.

2018-05-01

We compare the characteristics of the charged-current quasielastic (anti)neutrino scattering obtained in two different nuclear models, the phenomenological SuperScaling Approximation and the model using a realistic spectral function S(p, ɛ) that gives a scaling function in accordance with the (e, e‧ ) scattering data, with the recent data published by the MiniBooNE, MINER νA, and NOMAD collaborations. The spectral function accounts for the nucleon-nucleon (NN) correlations by using natural orbitals from the Jastrow correlation method and has a realistic energy dependence. Both models provide a good description of the MINER νA and NOMAD data without the need of an ad hoc increase of the value of the mass parameter in the axial-vector dipole form factor. The models considered in this work, based on the the impulse approximation (IA), underpredict the MiniBooNE data for the flux-averaged charged-current quasielastic {ν }μ ({\\bar{ν }}μ ){+}12\\text{C} differential cross section per nucleon and the total cross sections, although the shape of the cross sections is represented by the approaches. The discrepancy is most likely due to missing of the effects beyond the IA, e.g., those of the 2p–2h meson exchange currents that have contribution in the transverse responses.

Charge-exchange giant resonances as probes of nuclear structure

International Nuclear Information System (INIS)

Blomgren, J.

2001-09-01

Giant resonances populated in charge-exchange reactions can reveal detailed information about nuclear structure properties, in spite of their apparent featurelessness. The (p,n) and (n,p) reactions - as well as their analog reactions - proceed via the same nuclear matrix element as beta decay. Thereby, they are useful for probing electroweak properties in nuclei, especially for those not accessible to beta decay. The nuclear physics aspects of double beta decay might be investigated in double charge-exchange reactions. detailed nuclear structure information, such as the presence of ground-state correlations, can be revealed via identification of 'first-forbidden' transitions. In addition, astrophysics aspects and halo properties of nuclei have been investigated in charge exchange. Finally, these experiments have questioned our knowledge of the absolute strength of the strong interaction

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

Charge-exchange breakup of the deuteron with the production of two protons and spin structure of the amplitude of the nucleon charge transfer reaction

International Nuclear Information System (INIS)

Glagolev, V.V.; Lyuboshits, V.L.; Lyuboshits, V.V.; Piskunov, N.M.

1999-01-01

In the framework of the impulse approximation, the relation between the effective cross section of the charge-exchange breakup of a fast deuteron d + a → (pp) + b and the effective cross section of the charge transfer process n + a → p + b is discussed. In doing so, the effects of the proton identity (Fermi-statistics) and of the Coulomb and strong interactions of protons in the final state are taken into account. The distribution over relative momenta of the protons, produced in the charge-exchange process d + p → (pp) + n in the forward direction, is investigated. At the transfer momenta being close to zero the effective cross section of the charge-exchange breakup of a fast deuteron, colliding with the proton target, is determined only by the spin-flip part of the amplitude of the charge transfer reaction n + p → p + n at the zero angle. It is shown that the study of the process d + p → (pp) + n in a beam of the polarized (aligned) deuterons allows one, in principle, to separate two spin-dependent terms in the amplitude of the charge transfer reaction n + p → p + n, one of which does not conserve and the other one conserves the projection of the nucleon spin onto the direction of momentum at the transition of the neutron into the proton

Nucleon charge exchange reaction and antiproton elastic scattering at intermediate energies

International Nuclear Information System (INIS)

Kronenfeld, J.

1985-02-01

This work treats the medium energy nuclear (p,n) charge exchange reaction to analog states and the low energy elastic scattering of antiprotons and investigates the central aspects of a microscopic theory based on multiple-scattering series which are pertinent to these reactions. A two-step term of the Distorted Wave Impulse Approximation (DWIA) in treating the (p,n) reaction, was included. For the very absorptive p-bar interaction with nuclei we conjecture that a partial infinite summation, constituing a renormalization of the single scattering term of the optical potential series provides the dominant feature of this interaction. In this work the excitation of analog states is calculated and it was found that the (p,n) reaction is described fairly well by the DWIA. In the first part of the work the (p,n) reaction in the energy range 100-200 MeV was treated. The DWIA calculations were based on eikonalization. In the second part of the work the p-barA interaction with the selfconsistent scheme mentioned above, for scattering energies 30-120 MeV, was examined. (author)

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

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.

Coherent production of ρ - mesons in charged current antineutrino-neon interactions in BEBC

Science.gov (United States)

Marage, P.; Aderholz, M.; Allport, P.; Armenise, N.; Baton, J. P.; Berggren, M.; Bertrand, D.; Brisson, V.; Bullock, F. W.; Burkot, W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Guy, J.; Hamisi, F.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Katz, U. F.; Klein, H.; Matsinos, E.; Middleton, R. P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; O'Neale, S. W.; Parker, M. A.; Petiau, P.; Sacton, J.; Sansum, R. A.; Schmitz, N.; Simopoulou, E.; Vallée, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wells, J.; Wittek, W.

1987-09-01

Coherent production of ρ - mesons in charged current antineutrino interactions on neon nuclei is studied in the BEBC bubble chamber exposed to the CERN SPS wide band beam. The cross section is measured to be (95±25)·10-40 cm2 per neon nucleus, averaged over the beam energy spectrum. The distributions of kinematical variables and the absolute value of the cross section are in agreement with theoretical predictions based on the CVC hypothesis and the vector meson dominance model.

Coherent production of ρ- mesons in charged current antineutrino-neon interactions in BEBC

International Nuclear Information System (INIS)

Marage, P.; Bertrand, D.; Sacton, J.; Aderholz, M.; Katz, U.F.; Schmitz, N.; Wittek, W.; Allport, P.; Varvell, K.; Wells, J.; Baton, J.P.; Kasper, P.; Neveu, M.; Clayton, E.F.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Cooper-Sarkar, A.M.; Guy, J.; Venus, W.; Klein, H.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Matsinos, E.; Simopoulou, E.; Vayaki, A.

1987-01-01

Coherent production of ρ - mesons in charged antineutrino interactions on neon nuclei is studied in the BEBC bubbler chamber exposed to the CERN SPS wide band beam. The cross section is measured to be (95±25).10 -40 cm 2 per neon nucleus, averaged over the beam energy spectrum. The distributions of kinematical variables and the absolute value of the cross section are in agreement with theoretical predictions based on the CVC hypothesis and the vector meson dominance model. (orig.)

Charge exchange and ionization in atom-multiply-charged ion collisions

International Nuclear Information System (INIS)

Presnyakov, L.P.; Uskov, D.B.

1988-01-01

This study investigates one-electron transitions to the continuous and discrete spectra induced by a collision of atom A and multiply-charged ion B +Z with nuclear charge Z > 3. An analytical method is developed the charge-exchange reaction; this method is a generalization of the decay model and the approximation of nonadiabatic coupling of two states that are used as limiting cases in the proposed approach

Charge exchange in slow collisions of multiply charged ions with atoms

International Nuclear Information System (INIS)

Presnyakov, L.P.; Uskov, D.B.; Janev, R.K.

1982-01-01

Single-electron charge exchange between ions having a charge Z>6 and atoms is considered at relative velocities v< Z/sup 1/2/. An analytic method is developed for the solution of a multilevel problem that is a generalization of the decay model and of the approximation of nonadiabatic coupling between two states. Expressions are obtained for the reaction-product distributions in the principal and angular quantum numbers. The calculated total cross sections agree well with the experimental data on charge exchange of hydrogen atoms and molecules with nuclei. The theory describes the oscillations of the total cross section against the background of a monotonic growth as the charge is increased

Using reactive artificial muscles to determine water exchange during reactions

International Nuclear Information System (INIS)

Otero, T F; Martínez, J G; Zaifoglu, B

2013-01-01

Artificial muscles based on films of conducting polymers translate film volume variations, driven by electrochemical reactions (Faradaic motors), into macroscopic movements with generation of mechanical energy. The reaction promotes exchange of counterions (anions here) and solvent molecules with the electrolyte. Attributing here both the film volume variation and the movement originated by these exchanges of ions and solvent, the described angles can be used to quantify the exchanged solvent. Different angles described by bending muscles consuming equal driving charges in electrolytes having the same cation and different anions were measured. The number of exchanged counterions is given by the consumed charge and the ion valence: this is a Faradaic reaction. The described angle fraction due to the exchanged anions is given by the number of anions and the crystallographic radius. Taking as reference the anion giving the shorter angle, whatever the consumed charge, the relative number of solvent molecules exchanged by the polymeric membrane during a reversible reaction was determined. Actuators and artificial muscles can be used as useful tools for, at least, an initial study of the solvent exchange during reactions in reactive gels. (paper)

$\\beta$- 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...

Probing nuclear correlations with pion-nucleus double charge exchange

International Nuclear Information System (INIS)

Ginocchio, J.N.

1988-01-01

In this paper we have calculated the lowest order pion double charge reaction mechanism using shell model wavefunctions of medium weight nuclei. We have the sequential reaction mechanism in which the pion undergoes two single-charge exchange scatterings on the valence neutrons. The distortion of the incoming, intermediate, and outgoing pion are included. The closure approximation is made for the intermediate states with an average excitation energy used in the pion propagator. The double-charge exchange is assumed to take place on the valence nucleons which are assumed to be in one spherical shell model orbital. 34 refs., 5 figs., 3 tabs

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

Comparing neutrino and antineutrino scattering

International Nuclear Information System (INIS)

Barish, B.C.

1977-01-01

The charged current interaction is considered. The present situation with respect to the indications of new physics at high energies, especially in the context of what can be learned by comparing neutrino with antineutrino production is reviewed

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

Measurements of the inclusive neutrino and antineutrino charged current cross sections in MINERvA using the low-ν flux method

Science.gov (United States)

Devan, J.; Ren, L.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Budd, H.; Cai, T.; Carneiro, M. F.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Eberly, B.; Endress, E.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Gran, R.; Harris, D. A.; Higuera, A.; Hurtado, K.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman, Paolone, V.; Park, J.; Patrick, C. E.; Perdue, G. N.; Ramirez, M. A.; Ransome, R. D.; Ray, H.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Solano Salinas, C. J.; Tice, B. G.; Valencia, E.; Wolcott, J.; Wospakrik, M.; Minerva Collaboration

2016-12-01

The total cross sections are important ingredients for the current and future neutrino oscillation experiments. We present measurements of the total charged-current neutrino and antineutrino cross sections on scintillator (CH) in the NuMI low-energy beamline using an in situ prediction of the shape of the flux as a function of neutrino energy from 2-50 GeV. This flux prediction takes advantage of the fact that neutrino and antineutrino interactions with low nuclear recoil energy (ν ) have a nearly constant cross section as a function of incident neutrino energy. This measurement is the lowest energy application of the low-ν flux technique, the first time it has been used in the NuMI antineutrino beam configuration, and demonstrates that the technique is applicable to future neutrino beams operating at multi-GeV energies. The cross section measurements presented are the most precise measurements to date below 5 GeV.

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\

A study of single-meson production in neutrino and antineutrino charged-current interactions on protons

Science.gov (United States)

Allen, P.; Grässler, H.; Schulte, R.; Jones, G. T.; Kennedy, B. W.; O'Neale, S. W.; Gebel, W.; Hofmann, E.; Klein, H.; Mittendorfer, J.; Morrison, D. R. O.; Schmid, P.; Wachsmuth, H.; Barnham, K. W. J.; Clayton, E. F.; Hamisi, F.; Miller, D. B.; Mobayyen, M. M.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Saitta, B.; Shotton, P. N.; Towers, S. J.; Aachen-Birmingham-Bonn-CERN-London IC-Munich (MPI)-Oxford Collaboration

1986-01-01

We present results on exclusive single-charged pion and kaon production in neutrino and antineutrino interactions on protons in the energy range from 5 to 120 GeV. The data were obtained from exposures of BEBC to wide band beams at the CERN SPS. For invariant masses of the (pπ) system below 2 GeV, the pions originate predominantly from decays of baryon resonances excited by the weak charged current. Similarly, we observe the production of Λ(1520) decaying into p and K -. For invariant masses above 2 GeV pion production becomes peripheral by interaction of the weak current with a virtual π0. We establish a contribution of longitudinally polarised intermediate vector bosons to this process.

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.

Elastic scattering and charge exchange reaction studies with {sup 6}He, {sup 10,11}Be

Energy Technology Data Exchange (ETDEWEB)

Roussel-Chomaz, P; Cortina-Gil, M D; Mittig, W; Casandjian, J M; Chartier, M [Grand Accelerateur National d` Ions Lourds (GANIL), 14 - Caen (France); Alamanos, N; Auger, F; Fekou-Youmbi, V [CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d` Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l` Instrumentation Associee; Barrette, J [McGill Univ., Montreal, PQ (Canada); Blumenfeld, Y [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; and others

1996-12-31

The elastic scattering and charge exchange reaction of {sup 6}He, {sup 10,11}Be secondary beams on proton and {sup 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 refs.

Dissecting Reactor Antineutrino Flux Calculations

Science.gov (United States)

Sonzogni, A. A.; McCutchan, E. A.; Hayes, A. C.

2017-09-01

Current predictions for the antineutrino yield and spectra from a nuclear reactor rely on the experimental electron spectra from 235U, 239Pu, 241Pu and a numerical method to convert these aggregate electron spectra into their corresponding antineutrino ones. In the present work we investigate quantitatively some of the basic assumptions and approximations used in the conversion method, studying first the compatibility between two recent approaches for calculating electron and antineutrino spectra. We then explore different possibilities for the disagreement between the measured Daya Bay and the Huber-Mueller antineutrino spectra, including the 238U contribution as well as the effective charge and the allowed shape assumption used in the conversion method. We observe that including a shape correction of about +6 % MeV-1 in conversion calculations can better describe the Daya Bay spectrum. Because of a lack of experimental data, this correction cannot be ruled out, concluding that in order to confirm the existence of the reactor neutrino anomaly, or even quantify it, precisely measured electron spectra for about 50 relevant fission products are needed. With the advent of new rare ion facilities, the measurement of shape factors for these nuclides, for many of which precise beta intensity data from TAGS experiments already exist, would be highly desirable.

Measurement of the neutral to charged current cross section ratios for neutrino and antineutrino interactions on protons

International Nuclear Information System (INIS)

Mobayyen, M.

1986-01-01

The ratios R νp and R a ntiν a ntip of the neutral current to charged current cross sections for neutrino and antineutrino interactions on protons have been measured in BEBC. For a total transverse momentum of the charged hadrons above 0.45 GeV/c and a charged multiplicity of at least 3, it was found that R νp = 0.384±0.024±0.015 and R a ntiν a nti p = 0.338±0.014±0.016, corresponding to a value of sin 2 θ W (M W ) a nti M a nti S of 0.225±0.030. 20 refs

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

Spin alignment of ρ0 mesons produced in antineutrino and neutrino neon charged-current interactions

International Nuclear Information System (INIS)

Wittek, W.; Aderholz, M.; Schmitz, N.; Guy, J.; Cooper-Sarkar, A.M.; Venus, W.; Brisson, V.; Petiau, P.; Vallee, C.; Calicchio, M.; Erriquez, O.; Fogli-Muciaccia, M.T.; Jones, G.T.; Middleton, R.P.; O'Neale, S.W.; Varvell, K.; Klein, H.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Vayaki, A.

1987-01-01

In a bubble chamber experiment with BEBC the spin alignment parameter η=1/2(2ρ 00 -ρ 11 -ρ -1-1 ) is measured for ρ 0 mesons produced in deep inelastic charged-current antineutrino and neutrino interactions on neon. In the current fragmentation region η is found to be η ν =0.48±0.27(stat.)±0.15(syst.) for anti νNe and η ν =0.12±0.20(stat.)±0.10(syst.) for νNe interactions. (orig.)

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)

A study of single-meson production in neutrino and antineutrino charged-current interactions on protons

International Nuclear Information System (INIS)

Allen, P.; Graessler, H.; Schulte, R.; Gebel, W.; Hofmann, E.; Barnham, K.W.J.; Clayton, E.F.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Saitta, B.; Shotton, P.N.; Towers, S.J.

1986-01-01

We present results on exclusive single-charged pion and kaon production in neutrino and antineutrino interactions on protons in the energy range from 5 to 120 GeV. The data were obtained from exposures of BEBC to wide band beams at the CERN SPS. For invariant masses of the (pπ) system below 2 GeV, the pions originate predominantly from decays of baryon resonances excited by the weak charged current. Similarly, we observe the production of Λ(1520) decaying into p and K - . For invariant masses above 2 GeV pion production becomes peripheral by interaction of the weak current with a virtual π 0 . We establish a contribution of longitudinally polarised intermediate vector bosons to this process. (orig.)

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

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

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

Spin alignment of ρ0 mesons produced in antineutrino and neutrino neon charged-current interactions

Science.gov (United States)

Wittek, W.; Guy, J.; Adeholz, M.; Allport, P.; Baton, J. P.; Berggren, M.; Bertrand, D.; Brisson, V.; Bullock, F. W.; Burkot, W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Fogli-Muciaccia, M. T.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Klein, H.; Marage, P.; Middleton, R. P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; O'Neale, S. W.; Parker, M. A.; Petiau, P.; Sacton, J.; Sansum, R. A.; Schmitz, N.; Simopoulou, E.; Vallee, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wells, J.

1987-03-01

In a bubble chamber experiment with BEBC the spin alignment parameter η=1/2 (2ϱ00 - ϱ11 - ϱ-1-1) is measured for ϱ0 mesons produced in deep inelastic charged-current antineutrino and neutrono interactions on neon. In the current fragmentation region η is found to be ηv=0.48+/-0.27 (stat.)+/-0.15 (syst.) for vNe and ηv=0.12+/-0.20 (stat.)+/-0.10 (syst.) for vNe interactions Present address: University College London, London WC1E 6BT, UK.

Plan charge exchange scattering at high energies

International Nuclear Information System (INIS)

Saleem, M.; Bhatti, S.; Fazal-e-Aleem; Rafique, M.

1980-01-01

By a phenomenological choice of the residue functions, a very good fit with experiment for the pion-nucleon charge exchange reaction at Fermilab energies is obtained on a simple Regge-pole model using a quadratic rho trajectory and energy-independent parameters

Non-coherent contributions in charge-exchange reactions and η-η{sup '} mixing

Energy Technology Data Exchange (ETDEWEB)

Nekrasov, M.L. [NRC ' ' Kurchatov Institute' ' , Institute for High Energy Physics, Protvino (Russian Federation)

2017-05-15

We analyse K{sup -}p → (η,η{sup '},π{sup 0})Λ on the basis of the fit of data in a wide region of energies, and π{sup -}p → (η,η{sup '})n at the energies of GAMS-4π. We show that disagreements between the data and the predictions of Regge theory may be explained by the mode change of summation of intermediate contributions at increasing energy, from coherent to non-coherent. A method of experimental measurement of the non-coherent contributions is proposed. On the basis of available data on the charge-exchange reactions the η-η{sup '} mixing is estimated. (orig.)

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

Note on some charge exchange cross sections of inelastic pn and pp reactions in terms of the quark interchange concept

International Nuclear Information System (INIS)

Bakken, V.; Jacobsen, T.

The charge exchange cross sections observed for pN interactions at 19 GeV/c in terms of the quark-quark interchange concept are discussed. If one uu-pair and one dd-pair of sea-quarks are assigned to each initial nucleon in pn and pp inelastic reactions, and if these quarks are assumed to participate on equal footing with the valence quarks in a quark-quark interchange mechanism between the two initial nucleons, the ratios between some observed charge exchange cross sections are well reproduced. This indicates that in this model the sea-quarks contribute significantly to the particle production in low p(subT) hadronic processes. (Auth.)

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

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)

Charge-Transfer Effects in Ligand Exchange Reactions of Au25 Monolayer-Protected Clusters.

Science.gov (United States)

Carducci, Tessa M; Blackwell, Raymond E; Murray, Royce W

2015-04-16

Reported here are second-order rate constants of associative ligand exchanges of Au25L18 nanoparticles (L = phenylethanethiolate) of various charge states, measured by proton nuclear magnetic resonance at room temperature and below. Differences in second-order rate constants (M(-1) s(-1)) of ligand exchange (positive clusters ∼1.9 × 10(-5) versus negative ones ∼1.2 × 10(-4)) show that electron depletion retards ligand exchange. The ordering of rate constants between the ligands benzeneselenol > 4-bromobenzene thiol > benzenethiol reveals that exchange is accelerated by higher acidity and/or electron donation capability of the incoming ligand. Together, these observations indicate that partial charge transfer occurs between the nanoparticle and ligand during the exchange and that this is a rate-determining effect in the process.

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

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.

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)

Line-emission cross sections for the charge-exchange reaction between fully stripped carbon and atomic hydrogen in tokamak plasma

International Nuclear Information System (INIS)

Ida, K.; Kato, T.

1992-01-01

Line-emission cross sections of the charge-exchange reaction between fully stripped carbon and atomic hydrogen are measured in the energy range of 18 - 38 keV/amu in tokamak plasmas. The energy dependence of the emission cross sections for the transition of Δn = 8 - 7 and Δn = 7 - 6 and their ratios are compared with theoretical calculations. (author)

Coherent production of pions in nuclei with ({sup 3}He,t) charge exchange reaction at 2. GeV

Energy Technology Data Exchange (ETDEWEB)

Farhi, L.; Roy-Stephan, M.; Boyard, J.L. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Hennino, T.; Kagarlis, M.; Radvanyi, P. [Laboratoire National Saturne - Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France); Dahl, R.; Ellegaard, C. [Niels Bohr Inst., Copenhagen (Denmark); Augustiniak, W.; Zupranski, P. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)] [and others

1996-12-31

The ({sup 3}He,t) charge exchange reaction at 2. GeV incident energy with the new setup SPES IV-{pi} has been realized in order to study the coherent production process of pions. This setup allows to isolate the ground state of the target nucleus, and to sign this process without ambiguity. Some preliminary results in target excitation energy and transferred energy are given. (author). 8 refs.

Testing partonic charge symmetry at a high-energy electron collider

International Nuclear Information System (INIS)

Hobbs, T.J.; Londergan, J.T.; Murdock, D.P.; Thomas, A.W.

2011-01-01

We examine the possibility that one could measure partonic charge symmetry violation (CSV) by comparing neutrino or antineutrino production through charged-current reactions induced by electrons or positrons at a possible electron collider at the LHC. We calculate the magnitude of CSV that might be expected at such a facility. We show that this is likely to be a several percent effect, substantially larger than the typical CSV effects expected for partonic reactions.

Study of neutrino- and antineutrino interactions in a neon-hydrogen mixture using the CERN narrow band beam

International Nuclear Information System (INIS)

Schultze, K.

1977-01-01

The charged-current cross sections for neutrinos and antineutrinos on nucleons in the energy range 20-200 GeV are given. Taken in conjunction with the previous Gargamelle results, they show that sigma/E is almost constant with energy for antineutrinos, and falls with energy for neutrinos. Above 50 GeV, sigma/E is compatible with being constant for neutrinos and antineutrinos. Rates for the production of neutral current events, di-lepton events and strange particles are given. The rate of di-lepton production shows no evidence for the production of 'bottom' states. Finally there is no indication for a charged heavy lepton coupled to the muon neutrino. (orig./WL) [de

Recent results on neutrino, antineutrino charged current interactions at NAL

International Nuclear Information System (INIS)

Aubert, B.; Benvenuti, A.; Cline, D.; Ford, W.T.; Imlay, R.; Ling, T.Y.; Mann, A.K.; Messing, F.; Piccioni, R.L.; Pilcher, J.; Reeder, D.D.; Rubbia, C.; Stefanski, R.; Sulak, L.

The dependence of the neutrino cross section on energy has been measured to 160GeV. The ratio sigma(antineutrino)/sigma(neutrino) is measured up to 70GeV. Preliminary results are presented for the distributions of the scaling variables x, y observed in neutrino induced events

Mass and charge distributions in Fe-induced reactions

International Nuclear Information System (INIS)

Madani, H.; Mignerey, A.C.; Marchetti, A.A.; Weston-Dawkes, A.P.; Kehoe, W.L.; Obenshain, F.

1995-01-01

The charge and mass of the projectile-like fragments produced in the 12-MeV/nucleon 56 Fe + 165 Ho reaction were measured at a laboratory scattering angle of 16 degrees. The mass and charge distributions of the projectile-like fragments were generated as a function of total kinetic energy loss (TKEL), and characterized by their neutron and proton centroids and variances, and correlation factors. A weak drift of the system towards mass asymmetry, opposite to the direction which minimizes the potential energy of the composite system, was observed. The increase in the variances with energy loss is consistent with a nucleon exchange mechanism as a means for energy dissipation. Predictions of two nucleon exchange models, Randrup's and, Tassan-Got's models, are compared to the experimental results of the 672-MeV 56 Fe + 165 Ho reaction and to other Fe-induced reactions. The proton and neutron centroids were found to be generally better reproduced by Tassan-Got's model than by Randrup's model. The variances and correlation factor are well reproduced for asymmetric systems by both models

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

Theoretical estimates of supernova-neutrino cross sections for the stable even-even lead isotopes: Charged-current reactions

Science.gov (United States)

Almosly, W.; Carlsson, B. G.; Suhonen, J.; Toivanen, J.; Ydrefors, E.

2016-10-01

A detailed study of the charged-current supernova electron neutrino and electron antineutrino scattering off the stable even-mass lead isotopes A =204 , 206, and 208 is reported in this work. The proton-neutron quasiparticle random-phase approximation (pnQRPA) is adopted to construct the nuclear final and initial states. Three different Skyrme interactions are tested for their isospin and spin-isospin properties and then applied to produce (anti)neutrino-nucleus scattering cross sections for (anti)neutrino energies below 80 MeV. Realistic estimates of the nuclear responses to supernova (anti)neutrinos are computed by folding the computed cross sections with a two-parameter Fermi-Dirac distribution of the electron (anti)neutrino energies. The computed cross sections are compared with earlier calculations and the analyses are extended to take into account the effects coming from the neutrino oscillations.

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.))

Observation of shadowing of neutrino- and antineutrino-nucleus interactions and comparison with PCAC predictions

Science.gov (United States)

Allport, P. P.; Erriquez, O.; Guy, J.; Venus, W.; Aderholz, M.; Berggren, M.; Bullock, F. W.; Calicchio, M.; Coghen, T.; Cooper-Sarkar, A. M.; Jones, G. T.; Marage, P.; Mobayyen, M.; Morrison, D. R. O.; Neveu, M.; Parker, M. A.; Radojicic, D.; Sansum, R. A.; Saitta, B.; Schmitz, N.; Simopoulou, E.; O'neale, S.; Van Apeldoorn, G.; Varvell, K.; Vayaki, A.; Wachsmuth, H.; Wittek, W.; BEBC WA59 Collaboration

1989-12-01

Comparing the kinematical distributions of events obtained on neon and deuterium targets in similar experimental conditions reveals a reduction of the neutrino and antineutrino charged current cross section per nucleon in neon at low Q2. The effect, interpreted as due to geometric shadowing of the weak propagator in interactions of neutrinos and antineutrinos with nuclei, agrees well with predictions derived from PCAC.

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.

Observation of shadowing of neutrino- and antineutrino-nucleus interactions and comparison with PCAC predictions

International Nuclear Information System (INIS)

Allport, P.P.; Radojicic, D.; Guy, J.; Venus, W.; Cooper-Sarkar, A.M.; Aderholz, M.; Schmitz, N.; Wittek, W.; Berggren, M.; Jones, G.T.; O'Neale, S.; Varvell, K.; Marage, P.; Mobayyen, M.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Neveu, M.; Simopoulou, E.; Vayaki, A.; Apeldoorn, G. van

1989-01-01

Comparing the kinematical distributions of events obtained on neon and deuterium targets in similar experimental conditions reveals a reduction of the neutrino and antineutrino charged current cross section per nucleon in neon at low Q 2 . The effect, interpreted as due to geometric shadowing of the weak propagator in interactions of neutrinos and antineutrinos with nuclei, agrees well with predictions derived from PCAC. (orig.)

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

Production of strange particles in antineutrino interactions at the CERN PS

CERN Document Server

Erriquez, O; Bisi, V; Bonetti, S; Bonneaud, G; Bullock, F W; Cavalli, D; Escoubés, B; Fogli-Muciaccia, M T; Franzinetti, Carlo; Gamba, D; Guyonnet, J L; Halsteinslid, A; Huss, D; Jarlskog, C; Jones, T W; Marzari-Chiesa, A; Michette, A G; Myklebost, K; Natali, S; Nuzzo, S; Paty, M; Pullia, A; Racca, C; Riccati, L; Riester, J L; Rognebakke, A; Rollier, M; Romero, A; Sacco, R; Schäffer, M; Skjeggestad, O; Tvedt, B

1978-01-01

The authors have studied neutral strange particle production in the bubble chamber Gargamelle filled with propane and exposed to antineutrinos from the CERN PS. Cross sections are presented for Lambda , Sigma /sup 0/ and K/sup 0/ production. Associated production reactions ( Delta S=0) have been observed in the charged and the neutral current channels. From 45 candidates for the quasi-elastic reaction nu p to mu /sup +/ Lambda , on bound and free protons, estimates of the axial transition form factor M/sub A/ have been made using the total cross section and the t distribution. The weighted average from the two methods is M/sub A/=862+or-190 MeV. From a subsample of 15 candidates for nu interactions on free protons in propane, with (28+or-6)% background from nu interactions on bound protons, M/sub A/=883+or-243 MeV is obtained. The polarization of the Lambda hyperons has been studied for the quasi-elastic reaction. (11 refs).

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

First charged current data from the CERN-Dortmund-Heidelberg-Saclay neutrino experiment

International Nuclear Information System (INIS)

Kleinknecht, K.

1977-01-01

The CDHS Collaboration has analyzed data taken in the CERN narrow-band antineutrino and neutrino beams. From 12000 antineutrino and 36000 neutrino charged current events at neutrino energies between 30 GeV and 200 GeV, we obtain the average inelasticity and the cross-section ratio sigma antisub(ν)/sigmasub(ν) as a function of neutrino energy. On the basis of these data we cannot confirm the high y anomaly observed by previous experiments at Fermilab. Instead, the measured average inelasticity in anti neutrino reactions and the ratio of charged current total cross-sections sigma anti sub(ν)/sigma%sub(ν) are compatible with no energy variation within their errors in the energy range 30 + . (orig.) [de

Evidence for Sequence Scrambling and Divergent H/D Exchange Reactions of Doubly-Charged Isobaric b-Type Fragment Ions

Science.gov (United States)

Zekavat, Behrooz; Miladi, Mahsan; Al-Fdeilat, Abdullah H.; Somogyi, Arpad; Solouki, Touradj

2014-02-01

To date, only a limited number of reports are available on structural variants of multiply-charged b-fragment ions. We report on observed bimodal gas-phase hydrogen/deuterium exchange (HDX) reaction kinetics and patterns for substance P b10 2+ that point to presence of isomeric structures. We also compare HDX reactions, post-ion mobility/collision-induced dissociation (post-IM/CID), and sustained off-resonance irradiation-collision induced dissociation (SORI-CID) of substance P b10 2+ and a cyclic peptide with an identical amino acid (AA) sequence order to substance P b10. The observed HDX patterns and reaction kinetics and SORI-CID pattern for the doubly charged head-to-tail cyclized peptide were different from either of the presumed isomers of substance P b10 2+, suggesting that b10 2+ may not exist exclusively as a head-to-tail cyclized structure. Ultra-high mass measurement accuracy was used to assign identities of the observed SORI-CID fragment ions of substance P b10 2+; over 30 % of the observed SORI-CID fragment ions from substance P b10 2+ had rearranged (scrambled) AA sequences. Moreover, post-IM/CID experiments revealed the presence of two conformer types for substance P b10 2+, whereas only one conformer type was observed for the head-to-tail cyclized peptide. We also show that AA sequence scrambling from CID of doubly-charged b-fragment ions is not unique to substance P b10 2+.

Evidence for sequence scrambling and divergent H/D exchange reactions of doubly-charged isobaric b-type fragment ions.

Science.gov (United States)

Zekavat, Behrooz; Miladi, Mahsan; Al-Fdeilat, Abdullah H; Somogyi, Arpad; Solouki, Touradj

2014-02-01

To date, only a limited number of reports are available on structural variants of multiply-charged b-fragment ions. We report on observed bimodal gas-phase hydrogen/deuterium exchange (HDX) reaction kinetics and patterns for substance P b10(2+) that point to presence of isomeric structures. We also compare HDX reactions, post-ion mobility/collision-induced dissociation (post-IM/CID), and sustained off-resonance irradiation-collision induced dissociation (SORI-CID) of substance P b10(2+) and a cyclic peptide with an identical amino acid (AA) sequence order to substance P b10. The observed HDX patterns and reaction kinetics and SORI-CID pattern for the doubly charged head-to-tail cyclized peptide were different from either of the presumed isomers of substance P b10(2+), suggesting that b10(2+) may not exist exclusively as a head-to-tail cyclized structure. Ultra-high mass measurement accuracy was used to assign identities of the observed SORI-CID fragment ions of substance P b10(2+); over 30% of the observed SORI-CID fragment ions from substance P b10(2+) had rearranged (scrambled) AA sequences. Moreover, post-IM/CID experiments revealed the presence of two conformer types for substance P b10(2+), whereas only one conformer type was observed for the head-to-tail cyclized peptide. We also show that AA sequence scrambling from CID of doubly-charged b-fragment ions is not unique to substance P b10(2+).

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)

Hybrid method to resolve the neutrino mass hierarchy by supernova (anti)neutrino induced reactions

Science.gov (United States)

Vale, D.; Rauscher, T.; Paar, N.

2016-02-01

We introduce a hybrid method to determine the neutrino mass hierarchy by simultaneous measurements of responses of at least two detectors to antineutrino and neutrino fluxes from accretion and cooling phases of core-collapse supernovae. The (anti)neutrino-nucleus cross sections for 56Fe and 208Pb are calculated in the framework of the relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons p(bar nue,e+)n are obtained using heavy-baryon chiral perturbation theory. The modelling of (anti)neutrino fluxes emitted from a protoneutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside the exploding star. The particle emission rates from the elementary decay modes of the daughter nuclei are calculated for normal and inverted neutrino mass hierarchy. It is shown that simultaneous use of (anti)neutrino detectors with different target material allows to determine the neutrino mass hierarchy from the ratios of νe- and bar nue-induced particle emissions. This hybrid method favors neutrinos from the supernova cooling phase and the implementation of detectors with heavier target nuclei (208Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil or water is the appropriate choice.

Experimental determination of differential cross-sections of muonic neutrinos and muonic antineutrinos interactions

International Nuclear Information System (INIS)

Lutz, Anne-Marie.

1975-05-01

The experimental determination of muonic neutrinos and muonic antineutrinos differential cross-sections by the analysis of pictures taken in the CERN Gargamelle heavy liquid bubble chamber is presented. The methods used to solve experimental difficulties (muon identification, hadronic energy determination) and the errors on the experimental distributions are explained in detail. Then, the structure functions in charge changing interactions of neutrinos and antineutrinos are analyzed and interpreted in terms of parton distribution inside the nucleon [fr

A study of quasi-elastic muon (anti)neutrino scattering in he NOMAD experiment

International Nuclear Information System (INIS)

Lyubushkin, Vladimir

2009-01-01

We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions (v μ n→μ - p and v-bar μ p→μ + 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 v μ (v-bar μ ) charged current cross-section. The results for the flux averaged QEL cross-sections in the (anti)neutrino energy interval 3-100 GeV are qel >v μ = (0.92±0.02(stat)±0.06(syst))x10 -38 cm 2 and qel >v-bar μ = (0.81±0.05(stat)±0.09(syst))x10 -38 cm 2 for neutrino and antineutrino, respectively. The axial mass parameter MA was extracted from the measured quasi-elastic neutrino cross-section. The corresponding result is M 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 2 shape analysis of the high purity sample of v μ quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured MA 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 A is lower than those recently published by K2K and MiniBooNE collaborations. However, within the large errors quoted by these experiments on M A , these results are compatible with the more precise NOMAD value.

The Daya Bay antineutrino detector filling system and liquid mass measurement

Science.gov (United States)

Band, H. R.; Cherwinka, J. J.; Draeger, E.; Heeger, K. M.; Hinrichs, P.; Lewis, C. A.; Mattison, H.; McFarlane, M. C.; Webber, D. M.; Wenman, D.; Wang, W.; Wise, T.; Xiao, Q.

2013-09-01

The Daya Bay Reactor Neutrino Experiment has measured the neutrino mixing angle θ13 to world-leading precision. The experiment uses eight antineutrino detectors filled with 20-tons of gadolinium-doped liquid scintillator to detect antineutrinos emitted from the Daya Bay nuclear power plant through the inverse beta decay reaction. The precision measurement of sin22θ13 relies on the relative antineutrino interaction rates between detectors at near (400 m) and far (roughly 1.8 km) distances from the nuclear reactors. The measured interaction rate in each detector is directly proportional to the number of protons in the liquid scintillator target. A precision detector filling system was developed to simultaneously fill the three liquid zones of the antineutrino detectors and measure the relative target mass between detectors to < 0.02%. This paper describes the design, operation, and performance of the system and the resulting precision measurement of the detectors' target liquid masses.

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

The phenomenon of neutrino oscillation is becoming increasingly understood with results from accelerator-based and reactor-based experiments, but unanswered questions remain. The proper ordering of the neutrino mass eigenstates that compose the neutrino avor eigenstates is not completely known. We have yet to detect CP violation in neutrino mixing, which if present could help explain the asymmetry between matter and anti-matter in the universe. We also have not resolved whether sterile neutrinos, which do not interact in any Standard Model interaction, exist. Accelerator-based experiments appear to be the most promising candidates for resolving these questions; however, the ability of present and future experiments to provide answers is likely to be limited by systematic errors. A significant source of this systematic error comes from limitations in our knowledge of neutrino-nucleus interactions. Errors on cross-sections for such interactions are large, existing data is sometimes contradictory, and knowledge of nuclear effects is incomplete. One type of neutrino interaction of particular interest is charged current quasi-elastic (CCQE) scattering, which yields a final state consisting of a charged lepton and nucleon. This process, which is the dominant interaction near energies of 1 GeV, is of great utility to neutrino oscillation experiments since the incoming neutrino energy and the square of the momentum transferred to the final state nucleon, Q², can be reconstructed using the final state lepton kinematics. To address the uncertainty in our knowledge of neutrino interactions, many experiments have begun making dedicated measurements. In particular, the MINER A experiment is studying neutrino-nucleus interactions in the few GeV region. MINERvA is a fine-grained, high precision, high statistics neutrino scattering experiment that will greatly improve our understanding of neutrino cross-sections and nuclear effects that affect the final state particles

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.

Hybrid method to resolve the neutrino mass hierarchy by supernova (anti)neutrino induced reactions

Energy Technology Data Exchange (ETDEWEB)

Vale, D. [Department of Physics, Faculty of Science, University of Zagreb, Bijenička c. 32, HR-10000 Zagreb (Croatia); Rauscher, T. [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Paar, N., E-mail: dvale@phy.hr, E-mail: Thomas.Rauscher@unibas.ch, E-mail: npaar@phy.hr [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

2016-02-01

We introduce a hybrid method to determine the neutrino mass hierarchy by simultaneous measurements of responses of at least two detectors to antineutrino and neutrino fluxes from accretion and cooling phases of core-collapse supernovae. The (anti)neutrino-nucleus cross sections for {sup 56}Fe and {sup 208}Pb are calculated in the framework of the relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons p(ν-bar {sub e},e{sup +})n are obtained using heavy-baryon chiral perturbation theory. The modelling of (anti)neutrino fluxes emitted from a protoneutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside the exploding star. The particle emission rates from the elementary decay modes of the daughter nuclei are calculated for normal and inverted neutrino mass hierarchy. It is shown that simultaneous use of (anti)neutrino detectors with different target material allows to determine the neutrino mass hierarchy from the ratios of ν{sub e}- and ν-bar {sub e}-induced particle emissions. This hybrid method favors neutrinos from the supernova cooling phase and the implementation of detectors with heavier target nuclei ({sup 208}Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil or water is the appropriate choice.

AGM2015: Antineutrino Global Map 2015.

Science.gov (United States)

Usman, S M; Jocher, G R; Dye, S T; McDonough, W F; Learned, J G

2015-09-01

Every second greater than 10(25) antineutrinos radiate to space from Earth, shining like a faint antineutrino star. Underground antineutrino detectors have revealed the rapidly decaying fission products inside nuclear reactors, verified the long-lived radioactivity inside our planet, and informed sensitive experiments for probing fundamental physics. Mapping the anisotropic antineutrino flux and energy spectrum advance geoscience by defining the amount and distribution of radioactive power within Earth while critically evaluating competing compositional models of the planet. We present the Antineutrino Global Map 2015 (AGM2015), an experimentally informed model of Earth's surface antineutrino flux over the 0 to 11 MeV energy spectrum, along with an assessment of systematic errors. The open source AGM2015 provides fundamental predictions for experiments, assists in strategic detector placement to determine neutrino mass hierarchy, and aids in identifying undeclared nuclear reactors. We use cosmochemically and seismologically informed models of the radiogenic lithosphere/mantle combined with the estimated antineutrino flux, as measured by KamLAND and Borexino, to determine the Earth's total antineutrino luminosity at . We find a dominant flux of geo-neutrinos, predict sub-equal crust and mantle contributions, with ~1% of the total flux from man-made nuclear reactors.

Measurement of the neutral to charged current cross section ratios for neutrino and and antineutrino interactions on protons

Science.gov (United States)

Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; O'Neale, S. W.; Hoffmann, E.; Haidt, D.; Klein, H.; Mittendorfer, J.; Morrison, D. R. O.; Schmid, P.; Wachsmuth, H.; Hamisi, F.; Miller, D. B.; Mobayyen, M. M.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Retter, M. L.; Saitta, B.; Shotton, P. N.; Towers, S. J.; Bullock, F. W.; Burke, S.; Fitch, P. J.; Birmingham-Bonn-CERN-Imperial College-München(MPI)-Oxford-University College Collaboration

1986-10-01

The ratios Rvp and Rvp of the neutral current to charged current cross sections for neutrino and antineutrino interactions on protons have been measured in BEBC. The beam was the CERN SPS 400 GeV wideband beam. The bubble chamber, equipped with the standard External Muon Identifier, was surrounded with an additional plane of wire chambers (Internal Picket Fence), which was added to improve neutral current event identification. For a total transverse momentum of the charged hadrons above 0.45 GeV/ c and a charged multiplicity of at least 3, it was found that R vp = 0.384 ± 0.015 and R vp = 0.338 ± 0.014 ± 0.016, corresponding to a value of sin 2θ w(M woverlineMSof 0.225 ± 0.030 . Combining the results from hydrogen and an isoscalar target, the differences of the neutral current chiral coupling constants were found to be u2l- d2L = -0.080 ± 0.043 ± 0.012 and u2R- d2R = 0.021±0.055±0.028.

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

Antineutrino Oscillations in the Atmospheric Sector

International Nuclear Information System (INIS)

Himmel, Alexander I.

2011-01-01

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 ν μ → (bar ν) 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 eV 2 and sin 2 (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.

Measurement of the neutrino component of an antineutrino beam observed by a nonmagnetized detector

International Nuclear Information System (INIS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Fleming, B. T.; Linden, S. K.; Spitz, J.; Brice, S. J.; Brown, B. C.; Ford, R.; Garcia, F. G.; Kobilarcik, T.; Marsh, W.; Moore, C. D.; Polly, C. C.; Russell, A. D.; Stefanski, R. J.; Zeller, G. P.; Bugel, L.; Conrad, J. M.; Karagiorgi, G.; Nguyen, V.

2011-01-01

Two methods are employed to measure the neutrino flux of the antineutrino-mode beam observed by the MiniBooNE detector. The first method compares data to simulated event rates in a high-purity ν μ -induced charged-current single π + (CC1π + ) sample while the second exploits the difference between the angular distributions of muons created in ν μ and ν μ charged-current quasielastic (CCQE) interactions. The results from both analyses indicate the prediction of the neutrino flux component of the predominately antineutrino beam is overestimated--the CC1π + analysis indicates the predicted ν μ flux should be scaled by 0.76±0.11, while the CCQE angular fit yields 0.65±0.23. The energy spectrum of the flux prediction is checked by repeating the analyses in bins of reconstructed neutrino energy, and the results show that the spectral shape is well-modeled. These analyses are a demonstration of techniques for measuring the neutrino contamination of antineutrino beams observed by future nonmagnetized detectors.

Measurement of the neutral to charged current cross section ratios for neutrino and antineutrino interactions on protons

International Nuclear Information System (INIS)

Jones, G.T.; Jones, R.W.L.; Kennedy, B.W.; O'Neale, S.W.; Hoffmann, E.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Corrigan, G.; Myatt, G.; Radojicic, D.; Retter, M.L.; Saitta, B.; Shotton, P.N.; Towers, S.J.; Bullock, F.W.; Burke, S.; Fitch, P.J.

1986-01-01

The ratios R vp and R vp of the neutral current to charged current cross sections for neutrino and antineutrino interactions on protons have been measured in BEBC. The beam was the CERN SPS 400 GeV wideband beam. The bubble chamber, equipped with the standard External Muon Identifier, was surrounded with an additional plane of wire chambers (Internal Picket Fence), which was added to improve neutral current event identification. For a total transverse momentum of the charged hadrons above 0.45 GeV/c and a charged multiplicity of at least 3, it was found that R vp =0.384±0.024±0.015 and R vp =0.338±0.014±0.016, corresponding to a value of sin 2 θ w (M w ) MS of 0.225±0.030. Combining the results from hydrogen and an isoscalar target, the differences of the neutral current chiral coupling constants were found to be u L 2 -d L 2 =-0.080±0.043±0.012 and u R 2 -d R 2 =0.021±0.055±0.028. (orig.)

Invariant mass spectroscopy of {sup 19,17}C and {sup 14}B using proton inelastic and charge-exchange reactions

Energy Technology Data Exchange (ETDEWEB)

Satou, Y., E-mail: satou@phya.snu.ac.k [Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of); Nakamura, T. [Department of Physics, Tokyo Institute of Technology, Tokyo (Japan); Fukuda, N. [Institute of Physical and Chemical Research (RIKEN), Saitama (Japan); Sugimoto, T.; Kondo, Y.; Matsui, N.; Hashimoto, Y.; Nakabayashi, T.; Okumura, Y.; Shinohara, M. [Department of Physics, Tokyo Institute of Technology, Tokyo (Japan); Motobayashi, T.; Yanagisawa, Y.; Aoi, N.; Takeuchi, S.; Gomi, T.; Togano, Y. [Institute of Physical and Chemical Research (RIKEN), Saitama (Japan); Kawai, S. [Department of Physics, Rikkyo University, Tokyo (Japan); Sakurai, H. [Institute of Physical and Chemical Research (RIKEN), Saitama (Japan); Ong, H.J.; Onishi, T.K. [Department of Physics, University of Tokyo, Tokyo (Japan)

2010-03-01

The neutron-rich carbon isotopes {sup 19,17}C and the boron isotope {sup 14}B have been investigated, respectively, by the proton inelastic and charge-exchange reactions on a liquid hydrogen target at around 70 MeV/nucleon. The invariant mass method in inverse kinematics was employed to map the energy spectrum above the neutron decay threshold of the residual nuclei. New states on carbon isotopes are reported. An experimental capability of extracting beta-decay strengths via forward angle (p,n) cross sections on unstable nuclei is shown.

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)

Charge exchange cross-sections for multiply charged ions

International Nuclear Information System (INIS)

Midha, J.M.; Gupta, S.C.

1990-01-01

A new empirical relation for charge exchange cross-section has been proposed for different charge states of C, N and O colliding with neutral hydrogen. Results are compared with the experimental data. (Author)

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

Mass and charge distributions in chlorine-induced nuclear reactions

International Nuclear Information System (INIS)

Marchetti, A.A.

1991-01-01

Projectile-like fragments were detected and characterized in terms of A, Z, and energy for the reactions 37 Cl on 40 Ca and 209 Bi at E/A = 7.3 MeV, and 35 Cl, on 209 Bi at E/A = 15 MeV, at angles close to the grazing angle. Mass and charge distributions were generated in the N-Z plane as a function of energy loss, and have been parameterized in terms of their centroids, variances, and coefficients of correlation. Due to experimental problems, the mass resolution corresponding to the 31 Cl on 209 Bi reaction was very poor. This prompted the study and application of a deconvolution technique for peak enhancement. The drifts of the charge and mass centroids for the system 37 Cl on 40 Ca are consistent with a process of mass and charge equilibration mediated by nucleon exchange between the two partners, followed by evaporation. The asymmetric systems show a strong drift towards larger asymmetry, with the production of neutron-rich nuclei. It was concluded that this is indicative of a net transfer of protons from the light to the heavy partner, and a net flow of neutrons in the opposite direction. The variances for all systems increase with energy loss, as it would be expected from a nucleon exchange mechanism; however, the variances for the reaction 37 Cl on 40 Ca are higher than those expected from that mechanism. The coefficients of correlation indicate that the transfer of nucleons between projectile and target is correlated. The results were compared to the predictions of two current models based on a stochastic nucleon exchange mechanism. In general, the comparisons between experimental and predicted variances support this mechanism; however, the need for more realistic driving forces in the model calculations is indicated by the disagreement between predicted and experimental centroids

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 v_μ → $\\bar{v}$_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.

Exchanged cations and water during reactions in polypyrrole macroions from artificial muscles.

Science.gov (United States)

Valero, Laura; Otero, Toribio F; Martínez, José G

2014-02-03

The movement of the bilayer (polypyrrole-dodecylbenzenesulfonate/tape) during artificial muscle bending under flow of current square waves was studied in aqueous solutions of chloride salts. During current flow, polypyrrole redox reactions result in variations in the volumes of the films and macroscopic bending: swelling by reduction with expulsion of cations and shrinking by oxidation with the insertion of cations. The described angles follow a linear function, different in each of the studied salts, of the consumed charge: they are faradaic polymeric muscles. The linearity indicates that cations are the only exchanged ions in the studied potential range. By flow of the same specific charge in every electrolyte, different angles were described by the muscle. The charge and the angle allow the number and volume of both the exchanged cations and the water molecules (related to a reference) between the film to be determined, in addition to the electrolyte per unit of charge during the driving reaction. The attained apparent solvation numbers for the exchanged cations were: 0.8, 0.7, 0.6, 0.5, 0.5, 0.4, 0.25, and 0.0 for Na(+), Mg(2+), La(3+), Li(+), Ca(2+), K(+), Rb(+), and Cs(+), respectively. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exchange Reactions. Proceedings of the Symposium on Exchange Reactions

International Nuclear Information System (INIS)

1965-01-01

The mechanisms and kinetics of chemical reactions are of great interest to chemists. The study of exchange reactions in particular helps to shed light on the dynamics of chemical change, providing an insight into the structures and the reactivities of the chemical species involved. The main theme of this meeting was the subject of oxidation-reduction reactions in which the net result is the transfer of one or more electrons between the different oxidation states of the same element. Other studies reported included the transfer of protons, atoms, complex ligands or organic radicals between molecules. Heterogeneous exchange, which is of importance in many cases of catalytic action, was also considered. For a long time isotopic tracers have formed the most convenient means of studying exchange reactions and today a considerable amount of work continues to be done with their aid. Consequently, several papers presented at this Symposium reported on work carried out by purely radiochemical tracer methods. In recognition, however, of the important role which nuclear magnetic resonance and electron spin resonance play in this field, in particular in the study of fast reactions, a number of reports on investigations in which these techniques had been used was included in the programme. By kind invitation of the United States Government the Symposium on Exchange Reactions was held from 31 May to 4 June at the Brookhaven National Laboratory, Upton, Long Island, N.Y., USA. It was attended by 46 participants from nine countries and one inter-governmental organization. The publication of these Proceedings makes the contents of the papers and the discussion available to a wider audience

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

Nuclear effect study on nucleon structure functions, in comparison with antineutrino interactions on neon and deuterium

International Nuclear Information System (INIS)

Vallee, C.

1984-03-01

We have studied the nuclear effects on high energy antineutrino charged current interactions by comparing the data which were taken in the Bubble Chamber BEBC filled with Neon and Deuterium. On the one hand, the study of nuclear reinteractions gave us the possibility to estimate the formation time of hadrons. On the other hand, the comparison of structure functions does not show any significant difference between Neon and Deuterium. Though this result does not contradict the effects observed with charged leptons by the EMC and SLAC experiments, it is strongly incompatible with certain theoretical interpretations which implied a stronger effect in antineutrino interactions [fr

Determination of the direction to a source of antineutrinos via inverse beta decay in Double Chooz

Science.gov (United States)

Nikitenko, Ya.

2016-11-01

To determine the direction to a source of neutrinos (and antineutrinos) is an important problem for the physics of supernovae and of the Earth. The direction to a source of antineutrinos can be estimated through the reaction of inverse beta decay. We show that the reactor neutrino experiment Double Chooz has unique capabilities to study antineutrino signal from point-like sources. Contemporary experimental data on antineutrino directionality is given. A rigorous mathematical approach for neutrino direction studies has been developed. Exact expressions for the precision of the simple mean estimator of neutrinos' direction for normal and exponential distributions for a finite sample and for the limiting case of many events have been obtained.

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.

1977-08-01

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 2+ 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 +- 0.22 at 8.36 GeV/c and 1.38 +- 0.09 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 2+ )/sigma/sub tot/ (K - n → anti K 0 Δ - ) is 1.05 +- 0.16 at 8.36 GeV/c and 1.56 +- 0.08 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

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)

Negative pion topography by observation of γ-quanta after the charge exchange reaction π- p → π0 n

International Nuclear Information System (INIS)

Bueche, G.

It is shown that the gamma quanta from the π 0 decay after the charge exchange reaction π - p → nπ 0 can be used to map the capture region of a π - beam in hydrogen-containing substances. In view of the applications in radiotherapy, the detectors have to be placed laterally from the absorber volume. For such a geometry the probability distribution of γ-γ coincidences were calculated. The results show that the range of the beam and its lateral position can be determined to the order of one millimeter within a time short compared with irradiation times usual in radiotherapy

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

Can one distinguish τ-neutrinos from antineutrinos in neutral-current pion production processes?

International Nuclear Information System (INIS)

Hernandez, E.; Nieves, J.; Valverde, M.

2007-01-01

A potential way to distinguish τ-neutrinos from antineutrinos, below the τ-production threshold, but above the pion production one, is presented. It is based on the different behavior of the neutral-current pion production off the nucleon, depending on whether it is induced by neutrinos or antineutrinos. This procedure for distinguishing τ-neutrinos from antineutrinos neither relies on any nuclear model, nor it is affected by any nuclear effect (distortion of the outgoing nucleon waves, etc.). We show that neutrino-antineutrino asymmetries occur both in the totally integrated cross sections and in the pion azimuthal differential distributions. To define the asymmetries for the latter distributions we just rely on Lorentz-invariance. All these asymmetries are independent of the lepton family and can be experimentally measured by using electron or muon neutrinos, due to the lepton family universality of the neutral-current neutrino interaction. Nevertheless and to estimate their size, we have also used the chiral model of [E. Hernandez, J. Nieves, M. Valverde, hep-ph/0701149] at intermediate energies. Results are really significant since the differences between neutrino and antineutrino induced reactions are always large in all physical channels

Measurement of total cross sections for neutrino and antineutrino charged-current interactions in hydrogen and neon

International Nuclear Information System (INIS)

Aderholz, M.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Shotton, P.N.; Towers, S.J.; Miller, D.B.; Mobayyen, M.M.; Morrison, D.R.O.; Schmid, P.; Barnham, K.W.J.; Clayton, E.F.; Hamisi, F.; Baton, J.P.; Lagraa, M.; Bullock, F.W.; Fitch, P.J.; Sansum, R.A.; Coghen, T.; Cooper-Sarkar, A.M.; Guy, J.G.; Kasper, P.; Venus, W.; Middleton, R.P.; O'Neale, S.W.; Varvell, K.; Simopoulou, E.; Vayaki, A.; Vallee, C.; Wells, J.

1986-01-01

BEBC filled in turn with hydrogen, and with a neon-hydrogen mixture, was exposed to the CERN SPS wide band neutrino and antineutrino beams. The ratios of the charged-current cross sections per nucleon, sigma(νH 2 )/sigma(νNe) and sigma(anti νH 2 )/sigma(anti νNe), between 20 and 300 GeV were found to be 0.656+-0.020 and 1.425+-0.052, respectively. Multiplying these ratios by the revised cross sections in neon, sigma(νNe)/E=(0.723+-0.038)x10 -38 cm 2 /GeV per nucleon and sigma(anti νNe)/E=(0.351+-0.019)x10 -38 cm 2 /GeV per nucleon, and their ratio, sigma(anti νNe)/sigma(νNe)=0.485+-0.020, yields values for the total charged-current cross sections on protons, sigma(νp)/E and sigma(anti νp)/E, of (0.474+-0.029)x10 -38 cm 2 /GeV and (0.500+-0.032)x10 -38 cm 2 /GeV, respectively, and a value for the ratio sigma(anti νp)/sigma(νp) of 1.053+-0.066. (orig.)

EXFOR Basics. A short guide to the neutron reaction data exchange format

International Nuclear Information System (INIS)

McLane, V.; NUCLEAR DATA CENTER NETWORK

2000-01-01

This manual is intended as a guide to users of nuclear reaction data compiled in the EXFOR format, and is not intended as a complete guide to the EXFOR System. EXFOR is the exchange format designed to allow transmission of nuclear reaction data between the Nuclear Reaction Data Centers. In addition to storing the data and its' bibliographic information, experimental information is also compiled. The status (e.g., the source of the data) and history (e.g., date of last update) of the data set is also included. EXFOR is designed for flexibility in order to meet the diverse needs of the nuclear reaction data centers. It was originally conceived for the exchange of neutron data and was developed through discussions among personnel from centers situated in Saclay, Vienna, Livermore and Brookhaven. It was accepted as the official exchange format of the neutron data centers at Saclay, Vienna, Brookhaven and Obninsk, at a meeting held in November 1969.3 As a result of two meetings held in 1975 and 1976 and attended by several charged-particle data centers, the format was further developed and adapted to cover all nuclear reaction data. The exchange format should not be confused with a center-to-user format. Although users may obtain data from the centers in the EXFOR format, other center-to-user formats have been developed to meet the needs of the users within each center's own sphere of responsibility. The EXFOR format, as outlined, allows a large variety of numerical data tables with explanatory and bibliographic information to be transmitted in a format: l that is machine-readable (for checking and indicating possible errors); l that can be read by personnel (for passing judgment on and correcting errors). The data presently included in the EXFOR exchange file include: a complete compilation of experimental neutron-induced reaction data, a selected compilation of charged-particle-induced reaction data, a selected compilation of photon-induced reaction data

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

Measurement of the ratios of neutral-current to charged current cross sections of neutrino and antineutrino interactions in Ne

Science.gov (United States)

Bosetti, P. C.; Fritze, P.; Grässler, H.; Hasert, F. J.; Schulte, R.; Schultze, K.; Geich-Gimbel, C.; Nellen, B.; Pech, R.; Wünsch, B.; Grant, A.; Hulth, P. O.; Klein, H.; Morrison, D. R. O.; Pape, L.; Wachsmuth, H.; Vayaki, A.; Barnham, K. W. J.; Beuselinck, R.; Clayton, E. F.; Miller, D. B.; Mobayyen, M. M.; Petrides, A.; Albajar, C.; Myatt, G.; Saitta, B.; Wells, J.; Bolognese, T.; Vignaud, D.; Aachen-Bonn-CERN-Democritos-Imperial College, London-Oxford-Saclay Collaboration

1983-05-01

The ratios of neutral current to charged current cross sections of neutrino and antineutrino interactions in heavy Ne/H 2 mixture have been measured in BEBC. The beam was the CERN SPS 200 GeV/ c narrow band beam. The ratios were obtained using a cut in the transverse momentum of the hadronic system. In the standard Glashow-Salam-Weinberg model, our results correspond to the value of sin 2θw = 0.182 ± 0.020 ± 0.012. By combining this experiment with data from a hydrogen target the coupling constants uL2 and L2 are found to be 0.15 ± 0.04 and 0.19 ± 0.05, respectively.

Measurement of the ratios of neutral-current to charged current cross sections of neutrino and antineutrino interactions in Ne

International Nuclear Information System (INIS)

Bosetti, P.C.; Fritze, P.; Graessler, H.; Hasert, F.J.; Schulte, R.; Schultze, K.; Vayaki, A.; Barnham, K.W.J.; Beuselinck, R.; Clayton, E.F.; Miller, D.B.; Mobayyen, M.M.; Petrides, A.; Albajar, C.; Myatt, G.; Saitta, B.; Wells, J.

1983-01-01

The ratios of neutral current to charged current cross sections of neutrino and antineutrino interactions in heavy Ne/H 2 mixture have been measured in BEBC. The beam was the CERN SPS 200 GeV/c narrow band beam. The ratios were obtained using a cut in the transverse momentum of the hadronic system. In the standard Glashow-Salam-Weinberg model, our results correspond to the value of sin 2 THETAsub(w)=0.182+-0.020+-0.012. By combining this experiment with data from a hydrogen target the coupling constants usub(L) 2 and dsub(L) 2 are found to be 0.15+-0.04 and 0.19+-0.05, respectively. (orig.)

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.)

Experimental study of the double charge exchange reaction πsup(+)+24He→πsup(-)+4p between 1.5 and 2.0GeV/c

International Nuclear Information System (INIS)

Gaille, F.; Mureramanzi, S.; Bogdanski, M.; Jeanneret, J.B.; Jeannet, E.; Perrin, D.

1977-01-01

The double charge exchange reaction 2 4 He(πsup(+), πsup(-))4p has been studied with helium bubble chamber pictures at 1.46, 1.72 and 1.86GeV/c incident momenta. Results are presented about cross-sections, momentum spectra, angular and effective-mass distributions. The main features observed in this reactions are the low rate of events involving two spectator protons, the quasi-isotropic angular distribution of the negative pion and the abundant Δ (1232) and Δ(1670) resonance production

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.

Determination of the ratio r v = d v u v of the valence quark distributions in the proton from neutrino and antineutrino reactions on hydrogen and deuterium

Science.gov (United States)

Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; Klein, H.; Morrison, D. R. O.; Wachsmuth, H.; Miller, D. B.; Mobayyen, M. M.; Wainstein, S.; Aderholz, M.; Hantke, D.; Katz, U. F.; Kern, J.; Schmitz, N.; Wittek, W.; Borner, H. P.; Myatt, G.; Cooper-Sarkar, A. M.; Guy, J.; Venus, W.; Bullock, F. W.; Burke, S.

1994-12-01

Based on a QCD analysis of the parton momentum distributions in the proton, the ratio r v = d v / u v of the d and u valence quark distributions is determined as function of x in the range 0.01< x<0.7. The analysis uses data from neutrino and antineutrino charged current interactions on hydrogen and deuterium, obtained with BEBC in the (anti)neutrino wideband beam of the CERN SPS. Since v mainly depends on the deuterium/hydrogen ratios of the normalised x-y-Q 2-distributions many systematic effects cancel. It is found that r v decreases with increasing x, and drops below the naive SU(6) expectation of 0.5 for x≳0.3. An extrapolation of r v to x=1 is consistent with the hypothesis r v (1)=0.

Asymptotic theory of charge exchange for relativistic velocities and binding energies

International Nuclear Information System (INIS)

Demkov, Yu.N.; Ostrovskij, V.N.; Shevchenko, S.I.

1983-01-01

The asymptotic theory of charge exchange (ATCE) at a large shock parameter rho is applied to the case of relativistic velocities and binding energies. The charge exchange reaction (1+e)+2 → 1+(e+2), when an electron from the bound 1Ssub(1/2) state on one particle transforms to the 1Ssub(1/2) state on the other, is considered. Oasic features of the method are as follows: 1) the representation of the transition amplitude in the form of multidimensional integral over some hypersurface; 2) the use of the saddle-point method for calculating necessary multidimensional integrals; 3) the refinement of wave functions as compared with the case of the absence of the interaction. The ATCE (at rho → infinity) makes it possible to obtain analytical results whose accuracy is determined solely with the shock parameter rho. A basic term of charge exchange amplitude asymptotics for 1Ssub(1/2) → 1Ssub(1/2) transitions has been calculated. It is possible to consider the ATCE as a peculiar reference with which theoretical and experimental results can be compared as well as to use the ATCE as boundary conditions during numerical calculations

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)

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...

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 θ_mu < 17degree . The absolute cross-section # as function of neutrino energy and the differential cross-section dσ/ dx_bj 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.

High-resolution study of the Gamow-Teller strength distribution in the light nuclei 9B and 13N using the (3He,t) charge-exchange reaction at 420 MeV beam energy

International Nuclear Information System (INIS)

Scholl, Clemens

2010-01-01

Excited states in the light nuclei 9 B and 13 C were studied using the ( 3 He,t) charge-exchange reaction on 9 Be and 13 C targets. The measurements were performed at the research center for nuclear physics (RCNP) in Osaka, Japan, using the magnetic spectrometer Grand Raiden and the dispersive WS course. The 3 He beam with an energy of 420 MeV was accelerated by the RCNP Ring Cyclotron. The Grand Raiden spectrometer and the WS course allow to study the ( 3 He,t) charge-exchange reaction with an energy resolution of around 30 keV, which is one order of magnitude better than measurements with the (p,n) charge-exchange reaction. The high resolution allows to better separate individual states and to determine weak excitation strengths because of low background in the spectra. A total of 19 states in 13 N were studied, and a total of 20 states were observed in 9 B. Of these, 9 states in 13 C and 10 states in 9 B were identified as being excited by a Gamow-Teller transition. Charge-exchange reactions are related to beta-decay, and at zero momentum transfer a simple proportionality exists between the cross-section of the charge-exchange experiment and the Fermi (F) or Gamow-Teller (GT) beta-decay strength. While the Fermi strength B(F) is concentrated in the transition to the isobaric analog state, the Gamow-Teller strength B(GT) is scattered among the excited states. The main aim of the present study is to determine the B(GT) strengths in the nuclei 9 B and 13 N. The only charge-exchange study of 9 B was made 30 years ago with the (p,n) reaction and a resolution of around 300-400 keV. Many states, especially at high excitation energy, could not be resolved by that study. The present work was able to separate many weakly excited states with small decay width at high excitation energies (12-19 MeV) in 9 B and determine the B(GT) strength distribution by using recent high-precision beta-decay data. The results point to a strong difference in spatial structure between the

Prospects for Antineutrino Running at MiniBooNE

OpenAIRE

Wascko, M. O.

2006-01-01

MiniBooNE began running in antineutrino mode on 19 January, 2006. We describe the sensitivity of MiniBooNE to LSND-like nuebar oscillations and outline a program of antineutrino cross-section measurements necessary for the next generation of neutrino oscillation experiments. We describe three independent methods of constraining wrong-sign (neutrino) backgrounds in an antineutrino beam, and their application to the MiniBooNE antineutrino analyses.

Measurement of total cross sections for neutrino and antineutrino charged-current interactions in hydrogen and neon

Science.gov (United States)

Aderholz, M.; Corrigan, G.; Hoffmann, E.; Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Myatt, G.; Radojicic, D.; Schmid, P.; Schmitz, N.; Shotton, P. N.; Towers, S. J.; Wittek, W.; Barnham, K. W. J.; Baton, J. P.; Berggren, M.; Bertrand, D.; Bullock, F. W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Fogli-Muciaccia, M. T.; Guy, J. G.; Hamisi, F.; Hulth, P. O.; Kasper, P.; Klein, H.; Lagraa, M.; Marage, P.; Middleton, R. P.; O'Neale, S. W.; Parker, M. A.; Sacton, J.; Sansum, R. A.; Simopoulou, E.; Vallée, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachmuth, H.; Wells, J.

1986-06-01

BEBC filled in turn with hydrogen, and with a neon-hydrogen mixture, was exposed to the CERN SPS wide band neutrino and antineutrino beams. The ratios of the charged-current cross sections per nucleon, σ(νH2)/σ(νNe) and σ(νH2)/σ(νNe), between 20 and 300 GeV were found to be 0.656 +/- 0.020 and 1.425 +/- 0.052, respectively. Multiplying these ratios by the revised cross sections in neon, σ(νNe)/E = (0.723 +/- 0.038) × 10-38 cm2/GeV per nucleon and σ(νNe)/E = (0.351 +/- 0.019) × 10-38 cm2/GeV per nucleon, and their ratio, σ(νNe)/σ(νNe) = 0.485 +/- 0.020,, yields values for the total charged-current cross sections on protons, σ(νp)/E and σ(νp)/E, of (0.474 +/- 0.029) × 10-38 cm2/GeV and (0.500 +/- 0.032) × 10-38 cm2/GeV. respectively, and a value for the ratio σ(νp)/σ(νp) of 1.053 +/- 0.066. Present address: University of Glasgow, Glasgow G12 8QQ, UK.

Charge exchange scattering of charged gauge bosons by 't Hooft-Polyakov monopole

International Nuclear Information System (INIS)

Cvetic, G.; Yan, T.M.

1988-01-01

We have studied the scattering of a low energy charged gauge boson by a 't Hooft-Polyakov monopole in a spontaneously broken (SU(2) gauge theory. It is found that a charge exchange scattering occurs in the sector of zero total angular momentum. The charge exchange scattering has a nonvanishing finite amplitude when the size of the monopole becomes very small. Implications of our results are discussed. (orig.)

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

Charge exchange in collisions of beryllium with its ion.

Science.gov (United States)

Zhang, Peng; Dalgarno, Alexander; Côté, Robin; Bodo, Enrico

2011-11-14

Close-coupling calculations of the resonance and near resonance charge exchange in ion-atom collisions of Be at low and intermediate energies are presented. Accurate ab initio calculations are carried out of the Born-Oppenheimer potentials and the non-adiabatic couplings that are due to the finite nuclear masses and drive the near resonance charge exchange. We show that the near resonance charge exchange cross section follows Wigner's threshold law of inelastic processes for energies below 10(-8) eV and that the zero temperature rate constant for it is 4.5 × 10(-10) cm(3) s(-1). At collision energies much larger than the isotope shift of the ionization potentials of the atoms, we show that the near resonance charge exchange process is equivalent to the resonance charge exchange with cross sections having a logarithmic dependence. We also investigate the perturbation to the charge exchange process due to the non-adiabatic interaction to an electronic excited state. We show that the influence is negligible at low temperatures and still small at intermediate energies despite the presence of resonances.

PLT and PDX perpendicular charge-exchange analyzers

International Nuclear Information System (INIS)

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

1986-01-01

The perpendicular charge-exchange systems used on the poloidal divertor experiment and the Princeton large torus are comprised of ten-channel, mass-resolved, charge-exchange analyzers. Results from these systems indicate that instrumental effects can lead to erroneous temperature measurements during deuterium neutral beam injection or at low hydrogen concentrations

Charge exchange in a divertor plasma with excited particles

International Nuclear Information System (INIS)

Krasheninnikov, S.I.; Lisitsa, V.S.; Pigarov, A.Y.

1988-01-01

A model is constructed for the dynamics of neutral atoms and multicharged ions in a tokamak plasma. The influence of cascade excitation on charge exchange and ionization is taken into account. The effective rates of the resonant charge exchange of a proton with a hydrogen atom, the nonresonant charge exchange of a helium atom with a proton, and that of an α particle with atomic hydrogen are calculated as functions of the parameters of the divertor plasma in a tokamak. The charge exchange H + +He→H+He + can represent a significant fraction (∼30%) of the total helium ionization rate. Incorporating the charge exchange of He 2+ with atomic hydrogen under the conditions prevailing in the divertor plasma of the INTOR reactor can lead to substantial He 2+ →He + conversion and thereby reduce the sputtering of the divertor plates by helium ions

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

A search for fractional charge using the charm calorimeter

International Nuclear Information System (INIS)

Plunkett, R.

1984-01-01

We have searched for particles of charge Q=1/3 or Q=2/3 in neutrino-nucleus, antineutrino-nucleus, and proton-nucleus collisions, using the scintillator system of the CHARM calorimeter at CERN. No candidates for fractional charge are found. We have obtained limits which are on the order of 10 -5 fractionally charged particles produced per neutrino or antineutrino interaction. In the case of proton-nucleus interactions we find an upper limit on the production cross-section of highly penetrating fractionally charged particles which is approximately 10 -40 cm 2

A measurement of the proton structure functions from neutrino-hydrogen and antineutrino-hydrogen charged-current interactions

International Nuclear Information System (INIS)

Jones, G.T.; Jones, R.W.L.; Kennedy, B.W.; O'Neale, S.W.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Wainstein, S.; Corrigan, G.; Myatt, G.; Radojicic, D.; Shotton, P.N.; Towers, S.J.; Bullock, F.W.; Burke, S.

1989-01-01

Within the framework of the quark-parton model, the quark and anti-quark structure functions of the proton have been measured by fitting them to the distributions of the events in the Bjorken y variable. The data used form the largest sample of neutrino and antineutrino interactions on a pure hydrogen target available, and come from exposures of BEBC to the CERN wide band neutrino and antineutrino beams. It is found that the ratio d ν /u ν of valence quark distributions falls with increasing Bjorken x. In the context of the quark-parton model the results constrain the isospin composition of the accompanying diquark system. Models involving scattering from diquarks are in disagreement with the data. (orig.)

Construction of Rb charge exchange cell and characteristic experiment for He- ion production

International Nuclear Information System (INIS)

Lee, Hee Seock; Bak, Jun Gyo; Bak, Hae Ill

1991-01-01

The Rb charge exchange cell is constructed as the He - ion source of the SNU 1.5-MV Tandem Van de Graaff accelerator. the characteristic experiments is carried out in order to determine the optimum operational conditions of the cell. The He + ion beam with the energy of 1 - 10 keV, extracted from the duoplasmatron ion source, is passed through the Rb vapor to become He - ions by the two step charge exchange reaction, i.e., He + + Rb → He o* + Rb + and He o* + Rb → He - + Rb + . From the experimental results, it is found that the maximum fractional yield of He - ions is produced at He + /ion energy of 7 keV. The optimum temperatures of the oven and the canal are determined to be 370 deg C and 95 deg C respectively. Under the optimum operational condition the maximum fractional yield of He - ions is 2.42 ± 0.02 5. This charge exchange cell is proved to be an effective system for the production of He - ions. (Author)

Kinetics of hydrogen isotope exchange reactions

International Nuclear Information System (INIS)

Gold, V.; McAdam, M.E.

1975-01-01

Under the influence of tritium β-radiation, 1,4-dioxan undergoes hydrogen exchange with the solvent water. The inhibition of the reaction by known electron scavengers (Ag + , Cu 2+ , Ni 2+ , Co 2+ , Zn 2+ , H 3 + O) and also by species with high reactivity towards hydroxyl radicals but negligible reactivity towards solvated electrons (N 3 - , Br - , SCN - ) has been examined in detail. γ-irradiation similarly induces hydrogen exchange. The action of scavengers is interpreted as requiring the involvement of two separately scavengeable primary radiolysis products in the sequence of reactions leading to exchange. The presence of electron scavengers, even at high concentration, does not totally inhibit the exchange, and a secondary exchange route, involving a low vacancy state of inhibitor cations, is considered responsible for the 'unscavengeable' portion of the reaction, by providing an alternative exchange route. Analogies are drawn between the exchange reaction and other radiation-induced reactions that are thought to involve spur processes. Some implication of radiation-chemical studies in water-alcohol mixtures are indicated. (author)

Experimental spectrum of reactor antineutrinos and spectra of main fissile isotopes

Energy Technology Data Exchange (ETDEWEB)

Sinev, V. V., E-mail: vsinev@pcbai10.inr.ruhep.ru [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

2013-05-15

Within the period between the years 1988 and 1990, the spectrum of positrons from the inverse-beta-decay reaction on a proton was measured at the Rovno atomic power plant in the course of experiments conducted there. The measured spectrum has the vastest statistics in relation to other neutrino experiments at nuclear reactors and the lowest threshold for positron detection. An experimental reactor-antineutrino spectrum was obtained on the basis of this positron spectrum and was recommended as a reference spectrum. The spectra of individual fissile isotopes were singled out from the measured antineutrino spectrum. These spectra can be used to analyze neutrino experiments performed at nuclear reactors for various compositions of the fuel in the reactor core.

Quasi-elastic interactions and one-pion production by neutrinos and anti-neutrinos on a deuterium target

International Nuclear Information System (INIS)

Barlag, S.J.M.

1984-01-01

In this thesis, the weak charged current interactions of neutrinos and antineutrinos with nucleons are described, in which the neutrino scatters in a quasi-elastic way with the nucleon, leaving an excited nucleon state. The experiments have been performed in the bubble chamber BEBC, filled with deuterium and exposed to the CERN Wide Band (anti-)neutrino beams. This gave the opportunity to study both interactions on protons and on neutrons separately, whereas the measurement of the exclusive channels could be performed with a high precision. After a short introduction of the relevant theories (standard model; QCD; one-pion production models; FKR quark model), the experimental set-up at CERN is described as well as the bubble chamber picture facility in Amsterdam. Next, results of the neutrino and antineutrino experiments are given followed by a comparison with theory. (Auth.)

Pion double charge exchange

International Nuclear Information System (INIS)

Cooper, M.D.

1978-01-01

The pion double charge exchange data on the oxygen isotopes is reviewed and new data on 9 Be, 12 C, 24 Mg, and 28 Si are presented. Where theoretical calculations exist, they are compared to the data. 9 references

Effects of hadronic colour structure in quasi-elastic and charge-exchange scattering on nuclei

International Nuclear Information System (INIS)

Kopeliovich, B.Z.; Zakharov, B.G.

1986-01-01

Effects of hadronic hidden colour screening are considered in hadron-nucleus interaction. It is shown that in the quasi-free charge exchange-reaction nuclear matter becomes transparent for the scattered hadron if the momentum transfer is large enough. The available experimental data confirm this prediction of QCD

Short-baseline electron antineutrino disappearance study by using neutrino sources from {sup 13}C + {sup 9}Be reaction

Energy Technology Data Exchange (ETDEWEB)

Shin, Jae Won; Cheoun, Myung-Ki [Department of Physics and Origin of Matter and Evolution of Galaxies (OMEG) Institute, Soongsil University, Seoul 156-743 (Korea, Republic of); Kajino, Toshitaka [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Hayakawa, Takehito, E-mail: shine8199@skku.edu, E-mail: cheoun@ssu.ac.kr, E-mail: kajino@nao.ac.jp, E-mail: hayakawa.takehito@qst.go.jp [Quantum Beam Science Directorate (QUBS), Japan Atomic Energy Agency (JAEA), 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan)

2017-04-01

To investigate the existence of sterile neutrino, we propose a new neutrino production method using {sup 13}C beams and a {sup 9}Be target for short-baseline electron antineutrino (ν-bar {sub e} ) disappearance study. The production of secondary unstable isotopes which can emit neutrinos from the {sup 13}C + {sup 9}Be reaction is calculated with three different nucleus-nucleus (AA) reaction models. Different isotope yields are obtained using these models, but the results of the neutrino flux are found to have unanimous similarities. This feature gives an opportunity to study neutrino oscillation through shape analysis. In this work, expected neutrino flux and event rates are discussed in detail through intensive simulation of the light ion collision reaction and the neutrino flux from the beta decay of unstable isotopes followed by this collision. Together with the reactor and accelerator anomalies, the present proposed ν-bar {sub e} source is shown to be a practically alternative test of the existence of the Δ m {sup 2} ∼ 1 eV{sup 2} scale sterile neutrino.

Diffractive production of charmed strange mesons by neutrinos and antineutrinos

Science.gov (United States)

Asratyan, A. E.; Aderholz, M.; Ammosov, V. V.; Burkot, W.; Clayton, E. F.; Coghen, T.; Erriquez, O.; Gapienko, G. S.; Gapienko, V. A.; Guy, J.; Hantke, D.; Jones, G. T.; Kaftanov, V. S.; Katz, U. F.; Kern, J.; Korotkov, V. A.; Krutchinin, S. P.; Kubantsev, M. A.; Marage, P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; Sacton, J.; Schmitz, N.; Varvell, K.; Venus, W.; Wittek, W.; Zaetz, V. G.

1993-03-01

The diffractive production of charmed strange D {s/*} and possibly D s mesons by neutrinos and antineutrinos on nucleons in hydrogen, deuterium and neon targets is observed. The slope parameter of the t distribution is 3.3±0.8 (GeV)-2. The production rate per charged current neutrino interaction with an isoscalar target times the D{s/+}→φτ+ branching fraction is (1.03±0.27)×10-4.

Diffractive production of charmed strange mesons by neutrinos and antineutrinos

International Nuclear Information System (INIS)

Asratyan, A.E.; Kaftanov, V.S.; Krutchinin, S.P.; Kubantsev, M.A.; Aderholz, M.; Hantke, D.; Katz, U.F.; Kern, J.; Schmitz, N.; Wittek, W.; Ammosov, V.V.; Gapienko, G.S.; Gapienko, V.A.; Korotkov, V.A.; Zaetz, V.G.; Burkot, W.; Coghen, T.; Clayton, E.F.; Miller, D.B.; Mobayyen, M.M.; Erriquez, O.; Guy, J.; Venus, W.; Jones, G.T.; Varvell, K.; Marage, P.; Sacton, J.; Morrison, D.R.O.; Neveu, M.

1993-01-01

The diffractive production of charmed strange D s * and possibly D s mesons by neutrinos and antineutrinos on nucleons in hydrogen, deuterium and neon targets is observed. The slope parameter of the t distribution is 3.3±0.8 (GeV) -2 . The production rate per charged current neutrino interaction with an isoscalar target times the D s + →φπ + branching fraction is (1.03±0.27)x10 -4 . (orig.)

Statistical properties of reactor antineutrinos

CERN Document Server

Rusov, V D; Tarasov, V O; Shaaban, Y

2002-01-01

Based on the properties of the cascade statistics of reactor antineutrinos, the efficient method of searching for neutrino oscillations is offered. The determination of physical parameters of this statistics, i.e. the average number of fissions and the overage number of antineutrinos per fission, requires no a priori knowledge of the geometry and characteristics of the detector, the reactor power, and composition of nuclear fuel.

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

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.

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

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)

Fine structure of charge exchange lines observed in laboratory plasmas

Energy Technology Data Exchange (ETDEWEB)

Ida, K.; Nishimura, S. [National Inst. for Fusion Science, Nagoya (Japan); Kondo, K.

1997-01-01

The influence of the fine structure of charge exchange lines appears only at the plasma edge or in the recombining phase where the ion temperature is low enough. The observed spectra in Li III and C VI are consistent with the sum of fine-structure components populated by statistical weights (assuming complete l-mixing) not by direct charge exchange cross sections. Some discrepancy was observed in the intensity ratio of fine-structure components between the observation and calculation for C VI in the recombining phase. The fine-structure of charge exchange lines gives an apparent Doppler shift in plasma rotation velocity measurement using charge exchange spectroscopy. (author)

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.)

Quasi-free pion single charge exchange

International Nuclear Information System (INIS)

Ouyang, J.

1992-12-01

Cross sections for the quasi-free (QF) region for pion single charge exchange (SCX) were measured with beams of 475 MeV π - , 500 MeV π ± , and 400 MeV π - , with most data at 500 MeV π ± . The LAMPF π 0 spectrometer and a proton detector arm were placed on each side of the beam with different scattering angles. Up to twelve targets, from hydrogen to bismuth, were used. Both inclusive and coincidence measurements were performed. The extraction of peak shape and cross section for the QF peak, the effective number of nucleons involved in the reaction, mass dependence, and angular dependence were studied for the inclusive measurement. Calculations with the local random phase approximation (RPA) were used to understand the inclusive experimental results. A collection of experimental results is given for both inclusive and coincidence measurements

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

Resonance charge exchange processes

International Nuclear Information System (INIS)

Duman, E.L.; Evseev, A.V.; Eletskij, A.V.; Radtsig, A.A.; Smirnov, B.M.

1979-01-01

The calculation results for the resonance charge exchange cross sections for positive and negative atomic and molecular ions are given. The calculations are performed on the basis of the asymptotic theory. The factors affecting the calculation accuracy are analysed. The calculation data for 28 systems are compared with the experiment

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

Charge exchange of muons in gases

International Nuclear Information System (INIS)

Turner, R.E.; Senba, M.

1983-06-01

The effects of the charge exchange process on muon spin dynamics have been investigated using a density operator formalism with special interest placed upon the diamagnetic muon and paramagnetic muonium signals observed after thermalization. In the charge exchange region the dynamics of the spin density operator is assumed to be determined by the muonium hyperfine interaction and by electron capture and loss processes for muons. Analytical expressions are obtained for the amplitudes and phases of the diamagnetic muon and paramagnetic muonium signals as a function of the duration of the charge exchange region, tsub(c), which is inversely proportional to the number density of the moderating gas. The theoretical signals exhibit three features which have, as yet, to be experimentally observed, namely: i) that the amplitudes associated with the muonium Larmor frequency and with the hyperfine frequency are not, in general, equal, ii) that all the amplitudes are, in general, damped oscillatory functions of tsub(c) (temperature/pressure) and iii) that phase jumps occur when an amplitude decreases to zero and then increases with falling pressure. Fits to the experimental argon data are discussed in light of the above points

High-resolution study of the Gamow-Teller strength distribution in the light nuclei {sup 9}B and {sup 13}N using the ({sup 3}He,t) charge-exchange reaction at 420 MeV beam energy

Energy Technology Data Exchange (ETDEWEB)

Scholl, Clemens

2010-07-07

Excited states in the light nuclei {sup 9}B and {sup 13}C were studied using the ({sup 3}He,t) charge-exchange reaction on {sup 9}Be and {sup 13}C targets. The measurements were performed at the research center for nuclear physics (RCNP) in Osaka, Japan, using the magnetic spectrometer Grand Raiden and the dispersive WS course. The {sup 3}He beam with an energy of 420 MeV was accelerated by the RCNP Ring Cyclotron. The Grand Raiden spectrometer and the WS course allow to study the ({sup 3}He,t) charge-exchange reaction with an energy resolution of around 30 keV, which is one order of magnitude better than measurements with the (p,n) charge-exchange reaction. The high resolution allows to better separate individual states and to determine weak excitation strengths because of low background in the spectra. A total of 19 states in {sup 13}N were studied, and a total of 20 states were observed in {sup 9}B. Of these, 9 states in {sup 13}C and 10 states in {sup 9}B were identified as being excited by a Gamow-Teller transition. Charge-exchange reactions are related to beta-decay, and at zero momentum transfer a simple proportionality exists between the cross-section of the charge-exchange experiment and the Fermi (F) or Gamow-Teller (GT) beta-decay strength. While the Fermi strength B(F) is concentrated in the transition to the isobaric analog state, the Gamow-Teller strength B(GT) is scattered among the excited states. The main aim of the present study is to determine the B(GT) strengths in the nuclei {sup 9}B and {sup 13}N. The only charge-exchange study of {sup 9}B was made 30 years ago with the (p,n) reaction and a resolution of around 300-400 keV. Many states, especially at high excitation energy, could not be resolved by that study. The present work was able to separate many weakly excited states with small decay width at high excitation energies (12-19 MeV) in {sup 9}B and determine the B(GT) strength distribution by using recent high-precision beta-decay data. The

76 FR 10498 - Exchange Visitor Program-Fees and Charges

Science.gov (United States)

2011-02-25

...--Fees and Charges AGENCY: Department of State. ACTION: Final rule. SUMMARY: The Department of State is amending its regulations regarding fees and charges for Exchange Visitor Program services. The fees permit the Department to recoup the cost of providing such Exchange Visitor Program services. DATES...

Assembly and Installation of the Daya Bay Antineutrino Detectors

International Nuclear Information System (INIS)

Band, H R; Heeger, K M; Hinrichs, P; Brown, R L; Gill, R; Carr, R; Dwyer, D A; Chen, X C; Chu, M C; Chen, X H; Heng, Y K; Cherwinka, J J; Greenler, L S; Draeger, E; Edwards, W R; Hoff, M; Goett, J; Gu, W Q; Ho, T H; He, W S

2013-01-01

The Daya Bay reactor antineutrino experiment is designed to make a precision measurement of the neutrino mixing angle θ 13 , and recently made the definitive discovery of its non-zero value. It utilizes a set of eight, functionally identical antineutrino detectors to measure the reactor flux and spectrum at baselines of ∼ 300–2000 m from the Daya Bay and Ling Ao Nuclear Power Plants. The Daya Bay antineutrino detectors were built in an above-ground facility and deployed side-by-side at three underground experimental sites near and far from the nuclear reactors. This configuration allows the experiment to make a precision measurement of reactor antineutrino disappearance over km-long baselines and reduces relative systematic uncertainties between detectors and nuclear reactors. This paper describes the assembly and installation of the Daya Bay antineutrino detectors

Neutrino-antineutrino pair production by hadronic bremsstrahlung

Science.gov (United States)

Bacca, Sonia

2016-09-01

I will report on recent calculations of neutrino-antineutrino pair production from bremsstrahlung processes in hadronic collisions and consider temperature conditions relevant for core collapse supernovae. Earlier studies on bremsstrahlung from neutron-neutron collisions showed that the approximation used in typical supernova simulation to model this process differs by about a factor of 2 from predictions based on chiral effective field theory, where the chiral expansion of two-body forces is considered up to the next-to-next-to-next-to-leading order. When the density of neutrons is large enough this process may compete with other non-hadronic reactions in the production of neutrinos, in particular in the case of μ and τ neutrinos, which are not generated by charged-current reactions. A natural question to ask is then: what is the effect of neutrino pair production from collisions of neutrons with finite nuclei? To tackle this question, we recently have addressed the case of neutron- α collisions, given that in the P-wave channels the neutron- α scattering features a resonance near 1 MeV. We find that the resonance leads to an enhanced contribution in the neutron spin structure function at temperatures in the range of 0 . 1 - 4 MeV. For significant density fractions of α in this temperature range, this process is competitive with contributions from neutron-neutron scattering. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada. This work was supported in parts by the Natural Sciences and Engineering Research Council (Grant Number SAPIN-2015-0003).

Nuclear charge-exchange excitations in a self-consistent covariant approach

International Nuclear Information System (INIS)

Liang, Haozhao

2010-01-01

-isospin resonances via the exchange terms, which leads to a profound effect in the nuclear isovector properties, e.g., the density dependence of the symmetry energy in nuclear matter. In the investigation of the isospin symmetry-breaking corrections for the superallowed β decays, it is found that the corrections δ c are sensitive to the proper treatments of the Coulomb mean field, but not so much to specific effective interactions. With these corrections δ c , the nucleus-independent Ft values are obtained in combination with the experimental ft values in the most recent survey and the improved radiative corrections. The values of Cabibbo-Kobayashi-Maskawa matrix element |V ud | thus obtained well agree with those obtained in neutron decay, pion decay, and nuclear mirror transitions, while the sum of squared top-row elements somehow deviates from the unitarity condition. Expressing the weak lepton-hadron interaction in the standard current-current form, the relevant transitions from the nuclear ground state to the excited states are calculated with RHF+RPA approach. In this way, the semileptonic weak interaction processes, e.g., neutrino reactions, charged lepton capture, β-decays, can be investigated microscopically and self-consistently. First illustrative calculations of the inclusive neutrino-nucleus cross section are performed for the 16 O(ν e ,e - ) 16 F reaction, and a good agreement with the previous theoretical studies is obtained. The main effort is dedicated to discussing the substantial influence of different recipes for the axial vector coupling strength and the theoretical low-lying excited states of the daughter nucleus. (author)

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...

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.

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

Charge exchange (p,n) reactions to the isobaric analog states of high Z nuclei: 73< or =Z< or =92

International Nuclear Information System (INIS)

Hansen, L.F.; Grimes, S.M.; Poppe, C.H.; Wong, C.

1983-01-01

Differential cross sections have been measured for the (p,n) reaction to the isobaric analog states of 181 Ta, 197 Au, 209 Bi, 232 Th, and 238 U at an incident energy of 27 MeV. Because of the importance of collective effects in this mass region, coupled-channel calculations have been carried out in the analysis of the data. Optical potentials obtained from the Lane model for the charge exchange reaction have been used in the simultaneous analysis of coupled proton and neutron channels. The sensitivity of the calculations to the different couplings between the levels and to the magnitude of the isovector potentials, V 1 and W 1 , is discussed. The good agreement obtained between the measured and calculated (p,n) angular distributions to the analog state confirms the validity of the Lane formalism for high-Z nuclei (Z> or =50). Elastic neutron differential cross sections inferred from the coupled-channel analysis are compared with measurements available in the literature in the energy range 7--8 MeV. The results of these calculations agree with the measured values as well as the results of calculations made using global neutron optical potential parameters optimized to fit neutron data

Charge-exchange processes in a divertor plasma with account for excited particles

International Nuclear Information System (INIS)

Krasheninnikov, S.I.; Lisitsa, V.S.; Pigarov, A.Yu.

1988-01-01

A model describing dynamics of neutral atoms and multicharge ions in tokamak plasma, taking account of cascade excitation effect on charge exchange and ionization processes, is constructed. Dependences of effective rate of processes of proton charge exchange on hydrogen atom and non-resonance helium atom charge exchange on proton and α-particle- on atomic hydrogen on tokamak divertor plasma parameters are calculated. It is shown that H + +He→H-He + charge exchange can make up a notable shave (∼30%) in full helium ionization rate. Accounting for Ge 2+ charge exchange on atomic hydrogen under INTOR reactor divertor plasma conditions can lead to substantial He 2+ →He + conversion and thus increase diverter plate sputtering by helium ions

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

Reactor Antineutrinos Signal all over the world

OpenAIRE

Ricci, B.; Mantovani, F.; Baldoncini, M.; Esposito, J.; Ludhova, L.; Zavatarelli, S.

2014-01-01

We present an updated estimate of reactor antineutrino signal all over the world, with particular attention to the sites proposed for existing and future geo-neutrino experiment. In our calculation we take into account the most updated data on Thermal Power for each nuclear plant, on reactor antineutrino spectra and on three neutrino oscillation mechanism.

Further results on muon-antineutrino-electron scattering

International Nuclear Information System (INIS)

Hasert, F.J.

1975-01-01

In a further study of the neutral current interactions muon-antineutrino e - →muon-antineutrino e - , the Gargamelle collaboration analyzed 70% of the photographic film from the Freon neutrino (antineutrino) experiment. Three non-ambiguous events were found, that correspond within a 90% confidence to an upper limit for the cross section below 0.17x10 -41 cm 2 /e - . A 0.46 event background was calculated, and the probability for the three events to be background is lower than 1%. Signal loss corrections were effected in terms of the Salam-Ward-Weinberg model, and an upper limit (sin 2 theta(W) 2 theta(W) are concluded to be 0.1 2 thate(W) [fr

Experimental test of exchange degeneracy in hypercharge exchange reactions

International Nuclear Information System (INIS)

Moffeit, K.C.

1978-10-01

Two pairs of line-reversed reactions π + P → K + Σ + , K - p → π - Σ + and π + p → K + Y* + (1385), K - p → π - Y* + (1385) provide an experimental test of exchange degeneracy in hypercharge exchange reactions. From their study it is concluded that in contrast to the lower energy data, the 11.5 results for the two pairs of reactions are consistent with exchange degeneracy predictions for both helicity-flip and nonflip amplitudes. The Y(1385) decay angular distributions indicate that the quark model and Stodolsky--Sakurai predictions are in agreement with the main features of the data. However, small violations are observed at small momentum transfer. While the Y(1385) vertex is helicity-flip dominated, the nonvanishing of T/sub 3/2 - 1/2/ and T/sub -3/2 1/2/ suggests some finite helicity nonflip contribution in the forward direction. 23 references

A mobile antineutrino detector with plastic scintillators

International Nuclear Information System (INIS)

Kuroda, Y.; Oguri, S.; Kato, Y.; Nakata, R.; Inoue, Y.; Ito, C.; Minowa, M.

2012-01-01

We propose a new type segmented antineutrino detector made of plastic scintillators for the nuclear safeguard application. A small prototype was built and tested to measure background events. A satisfactory unmanned field operation of the detector system was demonstrated. Besides, a detailed Monte Carlo simulation code was developed to estimate the antineutrino detection efficiency of the detector.

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.

A charge exchange chamber with built-in focusing

International Nuclear Information System (INIS)

Devienne, F.M.

1975-01-01

This invention concerns a charge exchange chamber with built-in focusing enabling a beam of low divergence neutrals to be obtained from a beam of ions of a given energy. The ion beam enters the charge exchange chamber filled with a neutral gas under pressure, the effect of which is an exchange of charges between the ions and the neutral molecules or atoms of the gas. The positive ions are substantially sent along the axis of the enclosure, characterised in that it includes electric facilities for concentrating the ions of the beam near this axis. These electric facilities are composed of a series of grids perpendicular to the direction of the ion jet, grids that are transparent and of negative potential and the potential of each of these grids increases in absolute value along the path of the ion jet in the enclosure [fr

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.)

Resonance charge exchange between excited states in slow proton-hydrogen collisions

International Nuclear Information System (INIS)

Tolstikhina, Inga Yu.; Kato, Daiji

2010-01-01

The theory of resonance charge exchange in slow collisions of a proton with a hydrogen atom in the excited state is developed. It extends the Firsov-Demkov theory of resonance charge exchange to the case of degenerate initial and final states. The theory is illustrated by semiclassical and quantum calculations of charge exchange cross sections between states with n=2 in parabolic and spherical coordinates. The results are compared with existing close-coupling calculations.

Detection of neutrinos, antineutrinos, and neutrino-like particles

Energy Technology Data Exchange (ETDEWEB)

Fischbach, Ephraim

2018-04-24

An apparatus for detecting the presence of a nuclear reactor by the detection of antineutrinos from the reactor can include a radioactive sample having a measurable nuclear activity level and a decay rate capable of changing in response to the presence of antineutrinos, and a detector associated with the radioactive sample. The detector is responsive to at least one of a particle or radiation formed by decay of the radioactive sample. A processor associated with the detector can correlate rate of decay of the radioactive sample to a flux of the antineutrinos to detect the reactor.

Charge state distribution of 16O from the 4He(12C,16O)γ reaction of astrophysical interest studied both experimentally and theoretically

International Nuclear Information System (INIS)

Liu, Shengjin; Sakurai, Makoto; Sagara, Kenshi; Teranishi, Takashi; Fujita, Kunihiro; Yamaguchi, Hiroyuki; Matsuda, Sayaka; Mitsuzumi, Tatsuki; Iwazaki, Makoto; Rosary, Mariya T.; Kato, Daiji; Tolstikhina, I.Yu.

2014-01-01

In astrophysics, 4 He( 12 C, 16 O)γ reaction places an important role. At Kyushu University Tandem accelerator Laboratory (KUTL), the measurement of 4 He( 12 C, 16 O)γ cross section is in progress in the energy range of astrophysical nuclear reaction. Since the charge state of product 16 O ions after passing through the gas target is spread and only one charge state can be measured at terminal detector, it is necessary to know the charge state distribution of 16 O ions passing through the He gas target precisely. Here, we report the charge state distribution of the 16 O recoils both experimentally and theoretically. Experimentally, we measured the equilibrium charge state distribution of 16 O ions in the windowless helium gas target with the beam energy of primary 16 O ions at 7.2, 4.5, and 3.45 MeV at KUTL. The measured results showed a Gaussian distribution for the charge state fraction. Theoretically, we proposed a framework for the charge state distribution study. Charge state distribution was computed by solving a set of differential equations including a series of charge exchange cross sections. For the ionization cross section, plane-wave Born approximation was applied and modified by taking target atomic screening as a function of momentum transfer into account. For the capture cross section, continuum distorted wave approximation was applied and the influence of the gas target density was taken into account in the process of electron capture. Using above charge exchange cross sections, the charge state evolution was simulated. According to the equilibrium distribution, we compared the theoretical calculation to the experimental data. After taking into account the density effects in the charge exchange process, the theoretical charge state distributions shows a good agreement with the experimental data. Both experimental and theoretical results are useful to understand the charge fraction of recoil oxygen created via 4 He( 12 C, 16 O)γ reaction

Ring current proton decay by charge exchange

Science.gov (United States)

Smith, P. H.; Hoffman, R. A.; Fritz, T.

1975-01-01

Explorer 45 measurements during the recovery phase of a moderate magnetic storm have confirmed that the charge exchange decay mechanism can account for the decay of the storm-time proton ring current. Data from the moderate magnetic storm of 24 February 1972 was selected for study since a symmetrical ring current had developed and effects due to asymmetric ring current losses could be eliminated. It was found that after the initial rapid decay of the proton flux, the equatorially mirroring protons in the energy range 5 to 30 keV decayed throughout the L-value range of 3.5 to 5.0 at the charge exchange decay rate calculated by Liemohn. After several days of decay, the proton fluxes reached a lower limit where an apparent equilibrium was maintained, between weak particle source mechanisms and the loss mechanisms, until fresh protons were injected into the ring current region during substorms. While other proton loss mechanisms may also be operating, the results indicate that charge exchange can entirely account for the storm-time proton ring current decay, and that this mechanism must be considered in all studies involving the loss of proton ring current particles.

Prospect for Charge Current Neutrino Interactions Measurements at the CERN-PS

CERN Document Server

Bernardini, P; Bozza, C; Brugnera, R; Cecchetti, A; Cecchini, S; Collazuol, G; Corso, F Dal; De Mitri, I; De Serio, M; Di Ferdinando, D; Dore, U; Dusini, S; Fabbricatore, P; Fanin, C; Fini, R A; Garfagnini, A; Grella, G; Kose, U; Laveder, M; Loverre, P; Longhin, A; Marsella, G; Mancarella, G; Mandrioli, G; Mauri, N; Medinaceli, E; Mezzetto, M; Muciaccia, M T; Orecchini, D; Paoloni, A; Pastore, A; Patrizii, L; Pozzato, M; Rescigno, R; Rosa, G; Simone, S; Sioli, M; Sirri, G; Spurio, M; Stanco, L; Stellacci, S; Surdo, A; Tenti, M; Togo, V

2011-01-01

Tensions in several phenomenological models grew with experimental results on neutrino/antineutrino oscillations at Short-Baseline (SBL) and with the recent, carefully recomputed, antineutrino fluxes from nuclear reactors. At a refurbished SBL CERN-PS facility an experiment aimed to address the open issues has been proposed [1], based on the technology of imaging in ultra-pure cryogenic Liquid Argon (LAr). Motivated by this scenario a detailed study of the physics case was performed. We tackled specific physics models and we optimized the neutrino beam through a full simulation. Experimental aspects not fully covered by the LAr detection, i.e. the measurements of the lepton charge on event-by-event basis and their energy over a wide range, were also investigated. Indeed the muon leptons from Charged Current (CC) (anti-)neutrino interactions play an important role in disentangling different phenomenological scenarios provided their charge state is determined. Also, the study of muon appearance/disappearance ca...

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

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

International Nuclear Information System (INIS)

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 + +H - 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 -1 . We also show that the widely used multichannel Landau--Zener theory is totally inadequate, to treat these transitions

A study of non-charge-exchange anti K0π- production in the reaction K-p→anti K0π-p at 4.2 GeV/c

International Nuclear Information System (INIS)

Engelen, J.J.; Holwerda, M.J.; Kittel, E.W.; Tieke, H.G.J.M.; Vergeest, J.S.M.; Grossmann, P.; Lyons, L.; McDowell, L.

1978-01-01

The anti K 0 π - system produced in the reaction K - p→anti K 0 π - p at 4.2 GeV/c is studied using high-statistics bubble-chamber data. The spin-parity structure is analyzed as a function of the anti K 0 π - mass up to 1.52 GeV. Production of K*(890) and K*(1420) is observed in helicity-0 and helicity-1 states. Contributions of natural and unnatural parity exchange are present. Considerable S-wave production is observed over the whole mass region considered. The t' dependence of the K*(890) and K*(1420) amplitudes is also studied. A comparison of the results on K*(890) production with the results of an analysis of charge-exchange K*(890) production, allows the separation of I=0 and I=1 exchange amplitudes. Some qualitative remarks are made concerning K*(1420) production. (Auth.)

Charge exchange emission from solar wind helium ions

NARCIS (Netherlands)

Bodewits, D; Hoekstra, R; Seredyuk, B; McCullough, RW; Jones, GH; Tielens, AGGM

2006-01-01

Charge exchange X-ray and far-ultraviolet (FUV) aurorae can provide detailed insight into the interaction between solar system plasmas. Using the two complementary experimental techniques of photon emission spectroscopy and translation energy spectroscopy, we have studied state-selective charge

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.)

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.

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.)

Ionization and charge exchange in atom collision with multicharged ion

International Nuclear Information System (INIS)

Presnyakov, L.P.; Uskov, D.B.

1984-01-01

Single-electron ionization and charge exchange are considered in collisions of an atom with an ion of charge Z> or =3 and at velocities v>Z -1 /sup // 3 . The approach is based on the Keldysh quasiclassical method. The ionization and charge exchange processes are described within the framework of a single formalism. Effects of rotation and translation are taken into account. The calculated total and partial cross sections agree well with the available experimental data. OFF

Anion exchange chromatography of 99mTc(Sn)-EHDP complexes: determination of the charge of the components and influence of pH and ligand concentration

International Nuclear Information System (INIS)

Huigen, Y.M.; Diender, M.; Gelsema, W.J.; De Ligny, C.L.

1991-01-01

The components of a 99m Tc(Sn)-EHDP complex mixture were separated by means of normal pressure and high-pressure anion exchange chromatography. Precautions were taken to prevent the dissociation of the complexes during chromatography. The charges of the components were determined according to the methods of Wilson and Pinkerton (1985) and Russell and Bischoff (1985). The values of the charges obtained with the two methods are not in agreement. Russell and Bischoff's method, in which a reference ion is used, must be preferred. However, even with this method the accuracy of the data obtained is probably limited, due to the difficulty of making corrections for activity coefficients of highly-charge ions at the rather high electrolyte concentrations that must be used in the ion exchange method. So, we think that it is only warranted to conclude that the mean charge of the components of 99m Tc(Sn)-EHDP is about -6 at pH 7, and that the charges of the individual components are in the range of -4 to -9. The influence of pH and ligand concentration in the reaction mixture was determined with high pressure anion exchange chromatography. It was found that a decrease in the pH of the reaction mixture favours the production of complexes with a long retention time, which leads to a slightly higher mean charge. The ligand concentration of the reaction mixture scarcely influenced the relative concentrations of the components. (author)

EXFOR basics: A short guide to the nuclear reaction data exchange format

International Nuclear Information System (INIS)

McLane, V.

1996-07-01

This manual is intended as a guide to users of nuclear reaction data compiled in the EXFOR format, and is not intended as a complete guide to the EXFOR System. EXFOR is the exchange format designed to allow transmission of nuclear data between the Nuclear Reaction Data Centers. In addition to storing the data and its' bibliographic information, experimental information, including source of uncertainties, is also compiled. The status and history of the data set is also included, e.g., the source of the data, any updates which have been made, and correlations to other data sets. EXFOR is designed for flexibility in order to meet the diverse needs of the nuclear data compilation centers. This format should not be confused with a center-to-user format. Although users may obtain data from the centers in the EXFOR format, other center-to-user formats have been developed to meet the needs of the users within each center's own sphere of responsibility. The exchange format, as outlined, allows a large variety of numerical data tables with explanatory and bibliographic information to be transmitted in an easily machine-readable format (for checking and indicating possible errors) and a format that can be read by personnel (for passing judgment on and correcting any errors indicated by the machine). The data presently included in the EXFOR exchange include: a complete compilation of experimental neutron-induced reaction data, a selected compilation of charged-particle induced reaction data, a selected compilation of photon-induced reaction data

Charge transfer reactions between gas-phase hydrated electrons, molecular oxygen and carbon dioxide at temperatures of 80-300 K.

Science.gov (United States)

Akhgarnusch, Amou; Tang, Wai Kit; Zhang, Han; Siu, Chi-Kit; Beyer, Martin K

2016-09-14

The recombination reactions of gas-phase hydrated electrons (H2O)n˙(-) with CO2 and O2, as well as the charge exchange reaction of CO2˙(-)(H2O)n with O2, were studied by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry in the temperature range T = 80-300 K. Comparison of the rate constants with collision models shows that CO2 reacts with 50% collision efficiency, while O2 reacts considerably slower. Nanocalorimetry yields internally consistent results for the three reactions. Converted to room temperature condensed phase, this yields hydration enthalpies of CO2˙(-) and O2˙(-), ΔHhyd(CO2˙(-)) = -334 ± 44 kJ mol(-1) and ΔHhyd(O2˙(-)) = -404 ± 28 kJ mol(-1). Quantum chemical calculations show that the charge exchange reaction proceeds via a CO4˙(-) intermediate, which is consistent with a fully ergodic reaction and also with the small efficiency. Ab initio molecular dynamics simulations corroborate this picture and indicate that the CO4˙(-) intermediate has a lifetime significantly above the ps regime.

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.

Dilepton and trilepton production by antineutrinos and neutrinos in neon

International Nuclear Information System (INIS)

Gerbier, G.; Baton, J.P.; Brou, D.; Kasper, P.; Kochowski, C.; Lagraa, M.; Neveu, M.; Guy, J.; Cooper-Sarkar, A.M.; Venus, W.; Armenise, N.; Calicchio, M.; Erriquez, O.; Nuzzo, S.; Bartley, J.H.; Bullock, F.W.; Fitch, P.J.; Leighton-Davis, S.; Sansum, R.A.; Clayton, E.F.; Miller, D.B.; Mobayyen, M.M.; Talebzadeh, M.; Coghen, T.; Hulth, P.O.; Simopoulou, E.; Vayaki, A.; Zevgolatakos, E.

1985-01-01

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+-7 μ + e - . 35+-7 μ + μ - events from anti ν 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 mode. Limits to prompt like sign μ + e + , μ + μ + and μ - μ - signals are given and compared with other experiments and with theoretical calculations. (orig.)

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.)

A partial wave analysis of the (3π)0 system from the charge exchange reaction π+n→π+π-π0p at 4 GeV/c

International Nuclear Information System (INIS)

Emms, M.J.; Jones, G.T.; Kinson, J.B.; Stacey, B.J.; Votruba, M.F.; Woodworth, P.L.; Bell, I.G.; Dale, M.; Major, J.V.; Charlesworth, J.A.; Crennell, D.J.; Sekulin, R.L.

1975-10-01

From a partial wave analysis of the (3π) 0 state in the charge exchange reaction π + n→π + π - π 0 p, strong unnatural parity is observed as well as natural parity production. The observed natural parity states are identified with well-established resonances. The unnatural parity production is consistent with Reggeized Deck model predictions, with the exception of the I = 1 Jsup(p) = 1 + state. Here there is no evidence for A 1 production at approximately 1.1 GeV, but the data could support resonance production at higher masses. (author)

The character of resonant charge exchange involving highly excited atoms

International Nuclear Information System (INIS)

Kosarim, A. V.; Smirnov, B. M.; Capitelli, M.; Laricchiuta, A.

2012-01-01

We study the process of resonant charge exchange involving excited helium atoms with the principal quantum number n = 5 colliding with the helium ion in the ground state in the collision energy range from thermal up to 10 eV. This information may be important for the analysis of planet atmospheres containing helium, in particular, for Jupiter’s atmosphere, but our basic interest is the transition from the quantum to classical description of this process, where, due to large cross sections, evaluations of the cross sections are possible. For the chosen process, quantum theory allows determining the cross section as a result of a tunnel electron transition, while classical theory accounts for over-barrier electron transitions. The classical theory additionally requires effective transitions between states with close energies. The analysis of these transitions for helium with n = 5 shows that electron momenta and their projections are mixed for a part of the states, while for other states, the mixing is absent. A simple criterion to separate such states is given. In addition, the main contribution to the cross section of resonant charge exchange follows from tunnel electron transitions. As a result, the quantum theory is better for calculating the cross sections of resonant charge exchange than the classical one and also allows finding the partial cross sections of resonant charge exchange, while the classical approach gives the cross section of resonant charge exchange in a simple manner with the accuracy of 20%.

A hybrid charged-particle guide for studying (n, charged particle) reactions

International Nuclear Information System (INIS)

Haight, R.C.; White, R.M.; Zinkle, S.J.

1983-01-01

Charged-particle transport systems consisting of magnetic quadrupole lenses have been employed in recent years in the study of (n, charged particle) reactions. A new transport system was completed at the laboratory that is based both on magnetic lenses as well as electrostatic fields. The magnetic focusing of the charged-particle guide is provided by six magnetic quadrupole lenses arranged in a CDCCDC sequence (in the vertical plane). The electrostatic field is produced by a wire at high voltage which stretches the length of the guide and is physically at the centre of the magnetic axis. The magnetic lenses are used for charged particles above 5 MeV; the electrostatic guide is used for lower energies. This hybrid system possesses the excellent focusing and background rejection properties of other magnetic systems. For low energy charged-particles, the electrostatic transport avoids the narrow band-passes in charged-particle energy which are a problem with purely magnetic transport systems. This system is installed at the LLNL Cyclograaff facility for the study of (n, charged particle) reactions at neutron energies up to 35 MeV. (Auth.)

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.

Yale High Energy Physics Research: Precision Studies of Reactor Antineutrinos

International Nuclear Information System (INIS)

Heeger, Karsten M.

2014-01-01

This report presents experimental research at the intensity frontier of particle physics with particular focus on the study of reactor antineutrinos and the precision measurement of neutrino oscillations. The experimental neutrino physics group of Professor Heeger and Senior Scientist Band at Yale University has had leading responsibilities in the construction and operation of the Daya Bay Reactor Antineutrino Experiment and made critical contributions to the discovery of non-zero$\\theta . Heeger and Band led the Daya Bay detector management team and are now overseeing the operations of the antineutrino detectors. Postdoctoral researchers and students in this group have made leading contributions to the Daya Bay analysis including the prediction of the reactor antineutrino flux and spectrum, the analysis of the oscillation signal, and the precision determination of the target mass yielding unprecedented precision in the relative detector uncertainty. Heeger's group is now leading an R\\&D effort towards a short-baseline oscillation experiment, called PROSPECT, at a US research reactor and the development of antineutrino detectors with advanced background discrimination.

Yale High Energy Physics Research: Precision Studies of Reactor Antineutrinos

Energy Technology Data Exchange (ETDEWEB)

Heeger, Karsten M. [Yale Univ., New Haven, CT (United States)

2014-09-13

This report presents experimental research at the intensity frontier of particle physics with particular focus on the study of reactor antineutrinos and the precision measurement of neutrino oscillations. The experimental neutrino physics group of Professor Heeger and Senior Scientist Band at Yale University has had leading responsibilities in the construction and operation of the Daya Bay Reactor Antineutrino Experiment and made critical contributions to the discovery of non-zero$\\theta_{13}$. Heeger and Band led the Daya Bay detector management team and are now overseeing the operations of the antineutrino detectors. Postdoctoral researchers and students in this group have made leading contributions to the Daya Bay analysis including the prediction of the reactor antineutrino flux and spectrum, the analysis of the oscillation signal, and the precision determination of the target mass yielding unprecedented precision in the relative detector uncertainty. Heeger's group is now leading an R\\&D effort towards a short-baseline oscillation experiment, called PROSPECT, at a US research reactor and the development of antineutrino detectors with advanced background discrimination.

Electron exchange reaction in anion exchangers as observed in uranium isotope separation

International Nuclear Information System (INIS)

Obanawa, Heiichiro; Takeda, Kunihiko; Seko, Maomi

1991-01-01

The mechanism of electron exchange in an ion exchanger, as occurring between U 4+ and UO 2 2+ in uranium isotope separation, was investigated. The height of the separation unit (H q ) in the presence of metal ion catalysts, as obtained from the separation experiments, was found to be almost coincident with the theoretical value of H q as calculated on the basis of the intrasolution acceleration mechanism of the metal ion, suggesting that the electron exchange mechanism in the ion-exchanger is essentially the same as that in the solution when metal ion catalysts are present. Separation experiments with no metal ion catalyst, on the other hand, showed the electron exchange reaction in the ion exchanger to be substantially higher than that in the solution, suggesting an acceleration of the electron exchange reaction by the ion-exchanger which is due to the close existence of higher order Cl - complexes of UO 2 2+ and U 4+ in the vicinity of the ion-exchange group. (author)

Theory of inclusive pionic reactions

International Nuclear Information System (INIS)

Oset, E.; Salcedo, L.L.; Strottman, D.

1985-01-01

A theory is developed for all the inclusive pion nuclear reactions, quasielastic, single charge exchange, double charge exchange and absorption, around the resonance region. The theory is based on the isobar hole model and makes an expansion in the number of particle-hole excitations. Up to 3p3h for pion absorption and 2p2h for quasielastic or charge exchange, where good convergence is found, are considered. The results obtained with this theory agree remarkably well with experiment for the different reactions and different nuclei in a wide region of energies around resonance

Molecular (Feshbach) treatment of charge exchange Li3++He collisions. II. Cross sections

International Nuclear Information System (INIS)

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

1986-01-01

Using the wave functions calculated in the preceding article, and a common translation factor, the charge exchange cross section for the Li 3+ +He(1s 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

Thermospheric neutral temperatures derived from charge-exchange produced N{sub 2}{sup +} Meinel (1,0) rotational distributions

Energy Technology Data Exchange (ETDEWEB)

Mutiso, C.K.; Zettergren, M.D.; Hughes, J.M.; Sivjee, G.G. [Embry-Riddle Aeronautical Univ., Daytona Beach, FL (United States). Space Physics Research Lab.

2013-06-01

Thermalized rotational distributions of neutral and ionized N{sub 2} and O{sub 2} have long been used to determine neutral temperatures (T{sub n}) during auroral conditions. In both bright E-region (charge-exchange reactions between high-altitude (>or similar 130 km) species provide an exception to this situation. In particular, the charge-exchange reaction O{sup +}({sup 2}D)+N{sub 2}(X) {yields}N{sub 2}{sup +} (A{sup 2}{Pi}{sub u}, {nu}' = 1) + O({sup 3}P) yields thermalized N{sub 2}{sup +} Meinel (1,0) emissions, which, albeit weak, can be used to derive neutral temperatures at altitudes of {proportional_to} 130 km and higher. In this work, we present N{sub 2}{sup +} Meinel (1,0) rotational temperatures and brightnesses obtained at Svalbard, Norway, during various auroral conditions. We calculate T{sub n} at thermospheric altitudes of 130-180 km from thermalized rotational populations of N{sub 2}{sup +} Meinel (1,0); these emissions are excited by soft electron (charge-exchange reactions. We model the contributions of the respective excitation mechanisms, and compare derived brightnesses to observations. The agreement between the two is good. Emission heights obtained from optical data, modeling, and ISR data are consistent. Obtaining thermospheric T{sub n} from chargeexchange excited N{sub 2}{sup +} Meinel (1,0) emissions provides an additional means of remotely sensing the neutral atmosphere, although certain limiting conditions are necessary. These include precipitation of low-energy electrons, and a non-sunlit emitting layer. (orig.)

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.

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 ν_μ → ν_e 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.

Improved measurement of electron antineutrino disappearance at Daya Bay

International Nuclear Information System (INIS)

An Fengpeng; Bai Jingzhi; An Qi

2013-01-01

We report an improved measurement of the neutrino mixing angle θ13 from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for sin 2 2θ 13 with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GW th were detected in six antineutrino detectors deployed in two near (flux-weighted baselines of 470 m and 576 m) and one far (1648 m) underground experimental halls. Using 139 days of data, 28909 (205308) electron antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to the expected number of antineutrinos assuming no oscillations at the far hall is 0.944±0.007(stat.)±0.003(syst.). An analysis of the relative rates in six detectors finds sin 2 2θ 13 =0.089±0.010(stat.)±0.005(syst.) in a three-neutrino framework. (authors)

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

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)

Study of isotopic exchange reactions of azidothymidine with tritium

International Nuclear Information System (INIS)

Sidorov, G.V.; Zverkov, Yu.B.; Myasoedov, N.F.

2003-01-01

Different reactions of isotopic exchange of azidothymidine (3 - azido-3 - desoxythymidine) with tritium, such as solid- and liquid-phase catalytic isotopic exchange with gaseous tritium and isotopic exchange in solution with tritium water, are investigated. It is determined that catalytic reactions of azidothymidine with gaseous tritium in solution lead to practically full reduction of azido group up to amino group. In reactions of solid-phase catalytic hydrogenation this process takes place too and 3 - azido-3 - desoxythymidine yield is from 20 to 70 %. Molar radioactivity of labelled with tritium azidothymidine prepared in reactions of solid-phase catalytic isotopic exchange with gaseous tritium and so by isotopic exchange in solution with tritium water does not exceed 0.5 Cu/mmol [ru

Gain measurements of the Ca-Xe charge exchange system. [for UV lasers

Science.gov (United States)

Michels, C. J.; Chubb, D. L.

1978-01-01

Charge-exchange-pumped Ca(+) was studied for possible positive laser gain at 370.6 and 315.9 nm using an Xe MPD arc as the Xe(+) source. The present paper describes the MPD arc, the calcium injection system, the diagnostics for gain, and spontaneous emission measurements and results. No positive gain measurements were observed. A small Xe-Ca charge exchange cross section compared to He-metal laser systems charge exchange cross sections is the most probable reason why the result was negative.

Charge exchange of solar wind ions in the Comet Halley coma

Science.gov (United States)

Shelley, E. G.; Ing-H. afgoldstein, B. E. AGGOLDSTEIN, R.; Ing-H. afgoldstein, B. E. AGGOLDSTEIN, R.

1986-01-01

The He(2+) and He(+) radial profiles measured by the Giotto mass spectrometer on the inbound trajectory to comet Halley are compared to a simple 1-dimensional charge exchange model. Results indicate that charge exchange alone cannot account for the observed radial profiles of He(2+) and He(+).

Neutrino scattering and the reactor antineutrino anomaly

Science.gov (United States)

Garcés, Estela; Cañas, Blanca; Miranda, Omar; Parada, Alexander

2017-12-01

Low energy threshold reactor experiments have the potential to give insight into the light sterile neutrino signal provided by the reactor antineutrino anomaly and the gallium anomaly. In this work we analyze short baseline reactor experiments that detect by elastic neutrino electron scattering in the context of a light sterile neutrino signal. We also analyze the sensitivity of experimental proposals of coherent elastic neutrino nucleus scattering (CENNS) detectors in order to exclude or confirm the sterile neutrino signal with reactor antineutrinos.

Production of antihydrogen via double charge exchange

Energy Technology Data Exchange (ETDEWEB)

Muellers, Andreas

2013-02-01

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

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

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

Analysis of a Mathematical Model of Lithium-Sulfur Cells Part III: Electrochemical Reaction Kinetics, Transport Properties and Charging

International Nuclear Information System (INIS)

Ghaznavi, Mahmoudreza; Chen, P.

2014-01-01

Highlights: • The discharge behavior of Li-S cells in wide range of exchange current densities of electrochemical reactions is studied. • Among all reduction reactions, 1/2 S 8(l) +e − ⇌1/2 S 8 2− and 1/2 S 2 2− +e − ⇌2S 2− play the most important role in capacity performance. • Low diffusion increases the precipitation of polysulfides in separator which may block the anode surface. • Large solubility of Li 2 S is needed for the model to be able to simulate the charging process. - Abstract: Sensitivity analysis of a mathematical model of a lithium-sulfur (Li-S) battery was performed by investigating the response of the model to variation of the exchange current densities, diffusion coefficients, and cathode thickness over a wide range; the results of the analysis were used to explain the some aspects of the behavior of the system which may be seen in experiments. In particular, among all the exchange current densities, the exchange current density of the elemental sulfur reduction has the most significant effect on the discharge capacity of the cell. The variation of the diffusion coefficients was also analyzed, providing information on the non-uniformity of precipitants in the cell after discharge. An optimum cathode thickness was presented to gain the highest capacity of the cell. Finally, the simulation of charging was studied, showing that the model needs a large solubility product of di-lithium sulfide to be able to simulate the charge process of a cell

Polarization of {sup 23}Ne, {sup 24m,25}Al and {sup 28}P produced through single nucleon pickup and charge-exchange reactions at 100 AMeV

Energy Technology Data Exchange (ETDEWEB)

Ohtsubo, T., E-mail: tohtsubo@np.gs.niigata-u.ac.jp; Hirano, H.; Takahashi, S. [Niigata Univ. (Japan); Matsuta, K.; Mihara, M.; Fukuda, M. [Osaka Univ. (Japan); Nagatomo, T. [RIKEN (Japan); Izumikawa, T. [Niigata Univ., RI Center (Japan); Momota, S. [Kochi Univ. of Tech. (Japan); Nishimura, D.; Komurasaki, J.; Ishikawa, D. [Osaka Univ. (Japan); Zhou, D. M.; Zheng, Y. N.; Zhu, S. Y. [China Institute of Atomic Energy (China); Kitagawa, A.; Kanazawa, M.; Torikoshi, M.; Sato, S. [Inage-ku, NIRS (Japan); Minamisono, T. [Fukui Univ. of Tech. (Japan)

2007-11-15

We measured the polarization of the {beta}-emitting {sup 23}Ne (I{sup {pi}} 5/2{sup +}, T{sub 1/2} = 37.24 s) and {sup 25}Al(I{sup {pi}} = 5/2{sup +}, T{sub 1/2} = 7.18 s) produced through the one nucleon pickup reactions and {sup 24m}Al(I{sup {pi}} = 1{sup +}, T{sub 1/2} 131 ms, E{sub ex} = 426 keV) and {sup 28}P(I{sup {pi}} = 3{sup +}, T{sub 1/2} = 270 ms) produced through charge-exchange reactions in the intermediate energy heavy ion collisions. We compared them with those from the projectile fragmentation process. The larger polarization seems to persistently be positive throughout the momentum distribution, and sharper momentum distributions suggest that nuclear friction mechanism is responsible for the polarization phenomena.

Coherent production of a1- mesons and (ρπ)- systems by antineutrinos on neon

International Nuclear Information System (INIS)

Marage, P.; Sacton, J.; Willocq, S.; Aderholz, M.; Wittek, W.; Allport, P.P.; Baton, J.P.; Neveu, M.; Burtovoy, V.; Clayton, E.F.; Mobayyen, M.M.; Wainstein, S.; Cooper-Sarkar, A.M.; Guy, J.; Venus, W.; Jones, G.T.; O'Neale, S.; Varvell, K.; Matsinos, E.; Simopoulou, E.; Vayaki, A.; Morrison, D.R.O.; Wachsmuth, H.; Sansum, R.A.

1991-01-01

The coherent production of 3π systems by charged current antineutrino interactions on neon nuclei is studied in the bubble chamber BEBC exposed to the CERN SPS wide band beam. The coherent signal is attributed mainly to (ρπ) production, where the (ρπ) system is either non-resonant or comes from the decay of a 1 mesons. The kinematical variables and the total cross section are compared with the predictions of the meson dominance model. (orig.)

Integrated readout of organic scintillator and ZnS:Ag/6LiF for segmented antineutrino detectors

International Nuclear Information System (INIS)

Kiff, Scott D.; Reyna, David; Monahan, James; Bowden, Nathaniel S.

2010-01-01

Antineutrino detection using inverse beta decay conversion has demonstrated the capability to measure nuclear reactor power and fissile material content for nuclear safeguards. Current efforts focus on aboveground deployment scenarios, for which highly efficient capture and identification of neutrons is needed to measure the anticipated antineutrino event rates in an elevated background environment. In this submission, we report on initial characterization of a new scintillation-based segmented design that uses layers of ZnS:Ag/ 6 LiF and an integrated readout technique to capture and identify neutrons created in the inverse beta decay reaction. Laboratory studies with multiple organic scintillator and ZnS:Ag/ 6 LiF configurations reliably identify 6 Li neutron captures in 60 cm-long segments using pulse shape discrimination.

Isotope exchange reaction on solid breeder materials

International Nuclear Information System (INIS)

Baba, A.; Nishikawa, M.; Eguchi, T.; Kawagoe, T.

2000-01-01

Lithium ceramic materials such as Li 2 O, LiAlO 2 , Li 2 ZrO 3 , Li 2 TiO 3 and Li 4 SiO 4 are considered to be as candidate for the tritium breeding material in a deuterium-tritium (D-T) fusion reactor. In the recent blanket designs, helium gas with hydrogen or deuterium is planned to be used as the blanket purge gas to reduce tritium inventory and promote tritium release from the breeding material. In addition, the rate of isotope exchange reaction between hydrogen isotopes in the purge gas and tritium on the surface of the breeding material is necessary to analyze the tritium release behavior from the breeding materials. However, the rate of isotope exchange reactions between hydrogen isotopes in the purge gas and tritium on the surface of those materials has not been quantified until recently. Recently, the present authors quantified the rate of isotope exchange reaction on Li 2 O and Li 2 ZrO 3 . The overall mass transfer coefficients representing the isotope exchange reaction between H 2 and D 2 O on breeding materials or the same between D 2 and H 2 O are experimentally obtained in this study. Comparison to isotope exchange reaction rates on various breeding materials is also performed in this study. Discussions about the effects of temperature, concentration of hydrogen in the purge gas or flow rate of the purge gas on the conversion of tritiated water to tritium gas are also performed

Performance of a high-precision calorimeter for the measurement of the antineutrino-source strength in the SOX experiment

Energy Technology Data Exchange (ETDEWEB)

Altenmueller, Konrad [Technische Universitaet Muenchen (Germany); Collaboration: BOREXINO-Collaboration

2016-07-01

A calorimeter was developed to measure the thermal power and thus the antineutrino-generation rate of a {sup 144}Ce - {sup 144}Pr antineutrino-source with < 1% overall accuracy for the SOX experiment. SOX is searching for neutrino oscillations at short baselines with the Borexino detector to investigate the existence of eV-scale sterile neutrinos. The calorimeter design is based on a copper heat exchanger with integrated water lines for the heat extraction, mounted around the source. A high precision measurement is possible thanks to an elaborate thermal insulation. In this talk, the design of the calorimeter is reviewed and results of calibration measurements are presented. The thermal insulation of the system was examined and heat losses were quantified. The methods to reconstruct the source power and the decay rate from measurements are described.

Charge exchange collisions in gases in the presence of competing processes

International Nuclear Information System (INIS)

Senba, Masayoshi; British Columbia Univ., Vancouver

1988-01-01

The slowing down of charged particles in noble gases has been investigated theoretically from the charge exchange regime down to thermal energy. A formalism has been developed which allows one to calculate the rate of energy loss, the collision rate, the slowing down time, the neutral fraction and other quantities of interest directly from the cross sections of the atomic process involved. The formalism has been applied to the case of muons in He where two experimental observables, the fraction of the neutral species (muonium) and the muon spin depolarisation during charge exchange, have been calculated. The calculations have reproduced experimental results very well. It has also been found that the elastic process at the end of the slowing down reduces the number of charge exchange collisions drastically, thus sensitively affecting the neutral fraction and the muon spin depolarisation. (author)

Improved Measurement of Electron-antineutrino Disappearance at Daya Bay

International Nuclear Information System (INIS)

Dwyer, D.A.

2013-01-01

With 2.5× the previously reported exposure, the Daya Bay experiment has improved the measurement of the neutrino mixing parameter sin 2 2θ 13 =0.089±0.010(stat)±0.005(syst). Reactor anti-neutrinos were produced by six 2.9 GW th commercial power reactors, and measured by six 20-ton target-mass detectors of identical design. A total of 234,217 anti-neutrino candidates were detected in 127 days of exposure. An anti-neutrino rate of 0.944±0.007(stat)±0.003(syst) was measured by three detectors at a flux-weighted average distance of1648 m from the reactors, relative to two detectors at 470 m and one detector at 576 m. Detector design and depth underground limited the background to 5±0.3% (far detectors) and 2±0.2% (near detectors) of the candidate signals. The improved precision confirms the initial measurement of reactor anti-neutrino disappearance, and continues to be the most precise measurement of θ 13

Improved Measurement of Electron-antineutrino Disappearance at Daya Bay

Energy Technology Data Exchange (ETDEWEB)

Dwyer, D.A. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2013-02-15

With 2.5× the previously reported exposure, the Daya Bay experiment has improved the measurement of the neutrino mixing parameter sin{sup 2}2θ{sub 13}=0.089±0.010(stat)±0.005(syst). Reactor anti-neutrinos were produced by six 2.9 GW{sub th} commercial power reactors, and measured by six 20-ton target-mass detectors of identical design. A total of 234,217 anti-neutrino candidates were detected in 127 days of exposure. An anti-neutrino rate of 0.944±0.007(stat)±0.003(syst) was measured by three detectors at a flux-weighted average distance of1648 m from the reactors, relative to two detectors at 470 m and one detector at 576 m. Detector design and depth underground limited the background to 5±0.3% (far detectors) and 2±0.2% (near detectors) of the candidate signals. The improved precision confirms the initial measurement of reactor anti-neutrino disappearance, and continues to be the most precise measurement of θ{sub 13}.

Catalytic process for tritium exchange reaction

International Nuclear Information System (INIS)

Hansoo Lee; Kang, H.S.; Paek, S.W.; Hongsuk Chung; Yang Geun Chung; Sook Kyung Lee

2001-01-01

The catalytic activities for a hydrogen isotope exchange were measured through the reaction of a vapor and gas mixture. The catalytic activity showed to be comparable with the published data. Since the gas velocity is relatively low, the deactivation was not found clearly during the 5-hour experiment. Hydrogen isotope transfer experiments were also conducted through the liquid phase catalytic exchange reaction column that consisted of a catalytic bed and a hydrophilic bed. The efficiencies of both the catalytic and hydrophilic beds were higher than 0.9, implying that the column performance was excellent. (author)

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.

Double charge exchange and generalized seniority

International Nuclear Information System (INIS)

Ginocchio, J.N.

1993-01-01

The double charge exchange transition matrix elements from an even-even target to the double isobaric analog state and the ground state are derived in the generalized seniority model as a function of the number of valence nucleons. Crucial differences with the seniority model are found and their consequences are discussed. (orig.)

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.

Isobaric analog states in rare-earth nuclei studied with the (3He,t) charge-exchange reaction at thetasub(L)=00

International Nuclear Information System (INIS)

Jaenecke, J.

1983-01-01

The ( 3 He, t) charge-exchange reaction leading to the ground-state isobaric analog states (IAS) of sup(152, 154, 156, 158, 160)Gd, sup(160, 162)Dy, sup(162, 164, 166, 168, 170)Er, sup(170, 172, 174, 176)Yb and sup(176, 178, 180)Hf has been studied at thetasub(L) = 0 0 and E( 3 He) = 60.5 MeV. The reaction 28 Si( 3 He, t) 28 P was used for energy calibration. The centroid energies of most IAS were determined to +- 6 keV. Coulomb displacement energies have been extracted from the measured Q-values. They display the influence of non-spherical nuclear shapes which increase the rms radii and lower the Coulomb displacement energies. The dependence on both quadrupole and hexadecapole deformations is apparent with deformation parameters in good agreement with results from other measurements. The total widths GAMMA of the IAS are in the range 30 to 110 keV. They increase more strongly with neutron excess than is known for the IAS of the Sn and Te isotopes. The width of the IAS of 176 Yb is anomalously low. The zero-degree ( 3 He, t) cross sections are in the range 5 to 20 μb/sr. They generally increase with neutron excess except for the sequence of Yb isotopes. No systematic dependence on (N - Z) appears to exist. Excitation energies and zero-degree cross sections for the reactions 28 Si( 3 He, t) 28 P, 16 O( 3 He, t) 16 F and 12 C( 3 He,t) 12 N are reported. (orig.)

Contribution of recently measured nuclear data to reactor antineutrino energy spectra predictions

Directory of Open Access Journals (Sweden)

Fallot M.

2013-12-01

Full Text Available This paper attempts to summarize the actual problematic of reactor antineutrino energy spectra in the frame of fundamental and applied neutrino physics. Nuclear physics is an important ingredient of reactor antineutrino experiments. These experiments are motivated by neutrino oscillations, i.e. the measure of the θ13 mixing angle. In 2011, after a new computation of the reactor antineutrino energy spectra, based on the conversion of integral data of the beta spectra from 235U, and 239;241Pu, a deficit of reactor antineutrinos measured by short baseline experiments was pointed out. This is called the “reactor anomaly”, a new puzzle in the neutrino physics area. Since then, numerous new experimental neutrino projects have emerged. In parallel, computations of the antineutrino spectra independant from the ILL data would be desirable. One possibility is the use of the summation method, summing all the contributions of the fission product beta decay branches that can be found in nuclear databases. Studies have shown that in order to obtain reliable summation antineutrino energy spectra, new nuclear physics measurements of selected fission product beta decay properties are required. In these proceedings, we will present the computation methods of reactor antineutrino energy spectra and the impact of recent beta decay measurements on summation method spectra. The link of these nuclear physics studies with short baseline line oscillation search will be drawn and new neutrino physics projects at research reactors will be briefly presented.

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

Comparative study on bromide and iodide ion-isotopic exchange reactions using strongly basic anion exchange resin Duolite A-113

International Nuclear Information System (INIS)

Lokhande, R.S.; Dole, M.H.; Singare, P.U.

2006-01-01

Kinetics of ion-isotopic exchange reaction was studied using industrial grade ion exchange resin Duolite A-113. The radioactive isotopes 131 I and 82 Br were used to trace the ion-isotopic exchange reaction. The experiments were performed in the temperature range of 26.0degC to 43.0degC and the concentration of external ionic solution varying from 0.005 M to 0.100 M. For bromide ion-isotopic exchange reaction, the calculated values of specific reaction rate, initial rate of bromide ion exchange, and amount of bromide ions exchanged were obtained higher than that for iodide ion-isotopic exchange reaction under identical experimental conditions. The observed variation in the results for two ion-isotopic exchange reactions was due to the difference in the ionic size of bromide and iodide ions. (author)

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.

The reactivity of anion-exchange resins by applying OT-for-OH exchange reaction in the equilibrium state

International Nuclear Information System (INIS)

Kano, Naoki; Nihei, Makoto; Imaizumi, Hiroshi

1996-01-01

In order to reveal the behavior of hydroxyl group in isotope exchange reaction, OT-for-OH exchange reaction between each anion-exchange resin (OH - form) and tritiated water (abbreviated as HTO water below) was observed at 80degC under the equilibrium. Anion-exchange resins used were Amberlite IRA-400, IRA-410 (both strongly basic), and IRA-94S (weakly basic). It can be thought that an HTO molecule dissociates into H + +OT - (or T + +OH - ). The activity of each resin based on OT-for-OH exchange reaction was measured with a liquid scintillation counter. From the above-mentioned, the following five were found. Isotope exchange reaction as 'atomic group' occurred between the OH group in each anion-exchange resin and the OT group in HTO water. The reactivity of strongly basic anion-exchange resin is larger than that of weakly basic one. The ratio of the reactivity of these resins can roughly be expressed as follows: (IRA-410): (IRA-400): (IRA-94S)=42: 7: 1. The degree of OT-for-OH exchange reaction may be smaller than that of T-for-H exchange reaction. The method used and results obtained in this work may be helpful to obtain the data for the prevention of T-contamination, especially to obtain the data from certain atomic groups including T. (author)

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)

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.

(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

Isotope exchange reaction in Li2ZrO3 packed bed

International Nuclear Information System (INIS)

Kawamura, Y.; Enoeda, M.; Okuno, K.

1998-01-01

To understand the release behavior of bred tritium in a solid breeder blanket, the tritium transfer rate and tritium inventory for various mass transfer processes should be investigated. The contribution of the surface reactions (adsorption, desorption and two kinds of isotope exchange reactions) to the release process cannot be ignored. It is believed that two kinds of isotope exchange reactions (gaseous hydrogen-tritiated water and water vapor-tritiated water) occur on the surface of the solid breeder materials when hydrogen is added to the sweep gas to enhance the tritium release rate. The isotope exchange reaction study in H-D systems was carried out using a Li 2 ZrO 3 packed bed. The exchange reaction between gaseous hydrogen and water was the rate controlling step among the two kinds of exchange reactions. The reaction rate constants were quantified, and experimental equations were proposed. The equilibrium constant of the isotope exchange reaction in the H-D system was obtained from experimental data and was found to be 1.17. (orig.)

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.

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.

Comparative study on ion-isotopic exchange reaction kinetics by application of tracer technique

International Nuclear Information System (INIS)

Lokhande, R.S.; Singare, P.U.

2007-01-01

The radioactive isotopes 131 I and 82 Br were used to trace the ion-isotopic exchange reactions using industrial grade ion exchange resins Amberlite IRA-400. The experiments were performed to understand the effect of temperature and concentration of ionic solution on kinetics of exchange reactions. Both the exchange reactions were greatly influenced by rise in temperature, which result in higher percentage of ions exchanged. For bromide ion-isotopic exchange reactions, the calculated values of specific reaction rate/min -1 , and amount of ions exchanged/mmol were obtained higher than that for iodide ion-isotopic exchange reactions under identical experimental conditions. The observed variation in the results for two ion-isotopic exchange reactions was due to the difference in the ionic size of bromide and iodide ions. (orig.)

Ion-Isotopic Exchange Reaction Kinetics using Anion Exchange Resins Dowex 550A LC and Indion-930A

Directory of Open Access Journals (Sweden)

P.U. Singare

2014-06-01

Full Text Available The present paper deals with the characterization of ion exchange resins Dowex 550A LC and Indion-930A based on kinetics of ion-isotopic exchange reactions for which the short lived radioactive isotopes 131I and 82Br were used as a tracers. The study was performed for different concentration of ionic solution varying from 0.001 mol/L to 0.004 mol/L and temperature in the range of 30.0 °C to 45.0 °C. The results indicate that as compared to bromide ion-isotopic exchange reaction, iodide exchange reaction take place at the faster rate. For both the ion-isotopic exchange reactions, under identical experimental conditions, the values of specific reaction rate increases with increase in the ionic concentration and decreases with rise in temperature. It was observed that at 35.00C, 1.000 g of ion exchange resins and 0.002 mol/L labeled iodide ion solution for iodide ion-isotopic exchange reaction, the values of specific reaction rate (min-1, amount of ion exchanged (mmol, initial rate of ion exchange (mmol/min and log Kd were 0.270, 0.342, 0.092 and 11.8 respectively for Dowex 550A LC resin, which was higher than the respective values of 0.156, 0.241, 0.038 and 7.4 as that obtained for Indion-930A resins. From the results, it appears that Dowex 550A LC resins show superior performance over Indion-930A resins under identical experimental conditions.

Coherent production of single pions and ρ mesons in charged-current interactions of neutrinos and antineutrinos on neon nuclei at the Fermilab Tevatron

Science.gov (United States)

Willocq, S.; Aderholz, M.; Akbari, H.; Allport, P. P.; Badyal, S. K.; Ballagh, H. C.; Barth, M.; Bingham, H. H.; Brucker, E. B.; Burnstein, R. A.; Cence, R. J.; Chatterjee, T. K.; Clayton, E. F.; Corrigan, G.; de Prospo, D.; Devanand; de Wolf, E.; Faulkner, P. J.; Foeth, H.; Fretter, W. B.; Gupta, V. K.; Hanlon, J.; Harigel, G.; Harris, F. A.; Jacques, P.; Jain, V.; Jones, G. T.; Jones, M. D.; Kafka, T.; Kalelkar, M.; Kohli, J. M.; Koller, E. L.; Krawiec, R. J.; Lauko, M.; Lys, J. E.; Marage, P.; Milburn, R. H.; Mittra, I. S.; Mobayyen, M. M.; Moreels, J.; Morrison, D. R.; Myatt, G.; Nailor, P.; Naon, R.; Napier, A.; Passmore, D.; Peters, M. W.; Peterson, V. Z.; Plano, R.; Rao, N. K.; Rubin, H. A.; Sacton, J.; Sambyal, S. S.; Schmitz, N.; Schneps, J.; Singh, J. B.; Singh, S.; Smart, W.; Stamer, P.; Varvell, K. E.; Verluyten, L.; Wachsmuth, H.; Wainstein, S.; Yost, G. P.

1993-04-01

The coherent production of π and ρ mesons in νμ(ν¯μ)-neon charged-current interactions has been studied using the Fermilab 15-foot bubble chamber filled with a heavy Ne-H2 mix and exposed to the Teva- tron quadrupole triplet (anti)neutrino beam. The νμ (ν¯μ) beam had an average energy of 80 GeV (70 GeV). From a sample corresponding to approximately 28 000 charged-current interactions, net signals of (53+/-9) μ+/-π-/+ coherent events and (19+/-7) μ+/-π-/+π0 coherent events are extracted. For E>10 GeV, the coherent pion production cross section is determined to be (3.2+/-0.7)×10-38 cm2 per neon nucleus whereas the coherent ρ production cross section is (2.1+/-0.8)×10-38 cm2 per neon nucleus. These cross sections and the kinematical characteristics of the coherent events at ||t||<0.1 GeV2 are found to be in general agreement with the predictions of a model based on the hadron dominance and, in the pion case, on the partially conserved axial-vector current hypothesis. Also discussed is the coherent production of systems consisting of three pions.

Charged current weak interactions at high energy

International Nuclear Information System (INIS)

Cline, D.

1977-01-01

We review high energy neutrino and antineutrino charged current interactions. An overview of the experimental data is given, including a discussion of the experimental status of the y anomaly. Locality tests, μ-e universality and charge symmetry invariance tests are discussed. Charm production is discussed. The experimental status of trimuon events and possible phenomenological models for these events are presented. (orig.) [de

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

Solar Wind Charge Exchange During Geomagnetic Storms

Science.gov (United States)

Robertson, Ina P.; Cravens, Thomas E.; Sibeck, David G.; Collier, Michael R.; Kuntz, K. D.

2012-01-01

On March 31st. 2001, a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 RE. The NASA/GSFC Community Coordinated Modeling Center (CCMe) employed a global magnetohydrodynamic (MHD) model to simulate the solar wind-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et aL then modeled the expected 50ft X-ray emission due to solar wind charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on July 14, 2000 (Bastille Day). We again modeled X-ray emission due to solar wind charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X-ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images.

Charge exchange and ionization of atoms in collisions with multicharged ions

International Nuclear Information System (INIS)

Presnyakov, L.P.; Uskov, D.B.

1987-01-01

Single-electron transition in continuous and discrete spectra, induced by A atom and B +2 multicharged ion collision with the charge Z>3 are investigated. A theory of quantum transitions in multilevel systems with ion-atom collisions is considered. Main results on charge exchange in slow (v 0 Z 1/2 ) collisions are presented. For analysis of charge exchange analytical method, being generalization of decay model and of approximation of nonadiabatic coupling of two states, that are included into a developed approach as limiting cases, is developed. The calculation results are compared with the available experimental data

Monitoring nuclear reactors with anti-neutrino detectors: the ANGRA project

Energy Technology Data Exchange (ETDEWEB)

Chimenti, Pietro; Leigui, Marcelo Augusto [UFABC - Universidade Federal do ABC. Rua Santa Adelia, 166. Bairro Bangu. Santo Andre - SP (Brazil); Anjos, Joao; Azzi, Gabriel; Rafael, Gama; Ademarlaudo, Barbosa; Lima, Herman; VAZ, Mario; Villar, Arthur [Centro Brasileiro de Pesquisas Fisicas - CBPF, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ - 22290-180 (Brazil); Gonzales, Luis Fernando; Bezerra, Thiago; Kemp, Ernesto [Unicamp, State University of Campinas, Cidade Universitaria ' Zeferino Vaz' , Barao Geraldo - Campinas, Sao Paulo (Brazil); Nunokawa, Hiroshi [Department of Physics, Pontifical Catholic University - PUC, Rua Marques de Sao Vicente, 225, 22451-900 Gavea - Rio de Janeiro - RJ (Brazil); Guedes, Germano; Faria, Paulo Cesar [Universidade Estadual de Feira de Santana - UEFS, Avenida Transnordestina, Novo Horizonte (Brazil); Pepe, Iuri [Universidade Federal da Bahia - UFBA (Brazil)

2010-07-01

We describe the status of the ANGRA Project, aimed at developing an anti-neutrino detector for monitoring nuclear reactors. Indeed the detection of anti-neutrinos provides a unique handle for non-invasive measurements of the nuclear fuel. This kind of measurements are of deep interest for developing new safeguards tools which may help in nuclear non-proliferation programs. The ANGRA experiment, placed at about 30 m from the core of the 4 GW Brazilian nuclear power reactor ANGRA II, is based on a water Cherenkov detector with about one ton target mass. A few thousand antineutrino interactions per day are expected. The latest results from simulations and the status of the construction are presented. (authors)

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.

Enhanced bimolecular exchange reaction through programmed coordination of a five-coordinate oxovanadium complex for efficient redox mediation in dye-sensitized solar cells.

Science.gov (United States)

Oyaizu, Kenichi; Hayo, Noriko; Sasada, Yoshito; Kato, Fumiaki; Nishide, Hiroyuki

2013-12-07

Electrochemical reversibility and fast bimolecular exchange reaction found for VO(salen) gave rise to a highly efficient redox mediation to enhance the photocurrent of a dye-sensitized solar cell, leading to an excellent photovoltaic performance with a conversion efficiency of 5.4%. A heterogeneous electron-transfer rate constant at an electrode (k0) and a second-order rate constant for an electron self-exchange reaction (k(ex)) were proposed as key parameters that dominate the charge transport property, which afforded a novel design concept for the mediators based on their kinetic aspects.

Charge transfer reactions in Xe plasma expansion

International Nuclear Information System (INIS)

Jiao, C. Q.; Garscadden, A.; Ganguly, B. N.

2007-01-01

Charge transfer reactions of fast Xe ions with hydrocarbons including methane (CH 4 ), ethene (C 2 H 4 ), and propane (C 3 H 8 ) are studied by adding these hydrocarbon gases into a cross flowing Xe plasma expansion. Branching ratios and relative reaction rates for the charge transfers of fast Xe + with each of the three hydrocarbon gases are measured under different rf powers of the inductively coupled Xe discharge. For CH 4 /Xe system, we find that fast Xe + reacts readily with CH 4 generating CH 4 + and CH 3 + in a ratio of 1:0.56, with an estimated rate coefficient of (2.3±0.3)x10 -10 cm 3 /s at 75 W rf power which slowly increases to (2.9±0.3)x10 -10 cm 3 /s at 250 W (error bars reflect only the uncertainties due to the unknown extent of the ion recombination that follows the charge transfer reaction). These observed charge transfer reactions are made possible by the kinetically excited Xe ions produced by free expansion of the plasma. For the C 2 H 4 /Xe system product ions C 2 H 4 + and C 2 H 2 + are observed, and for C 3 H 8 /Xe, C 2 H 4 + and C 2 H 5 + and minor product ions including C 2 H 2 + and C 3 H 7 + are observed

Fusion plasma losses due to the charge exchange of injected neutrals

International Nuclear Information System (INIS)

Bender, D.J.; Carlson, G.A.

1975-01-01

The interaction of a neutral beam, consisting of full, half and third energy components, with a mirror plasma is analyzed. The beam-plasma interaction is assumed to occur via ionization and charge exchange collisions. The plasma was approximated as being spherical in shape, having a uniform density, isotropic velocity distribution, and a mirror plasma energy distribution. It was found that to a first approximation, for plasma energies less than 100 keV, the charge exchange power loss (per injected atom) of the half energy component is at least twice that of the full energy component. For the third energy component, the loss is at least three times that of the full energy component. For some plasma conditions, the neutral beam can act as an energy sink for the plasma due to these charge exchange losses. (U.S.)

Neutrino versus antineutrino oscillation parameters at DUNE and Hyper-Kamiokande experiments

Science.gov (United States)

de Gouvêa, André; Kelly, Kevin J.

2017-11-01

Testing, in a nontrivial, model-independent way, the hypothesis that the three-massive-neutrinos paradigm properly describes nature is among the main goals of the current and the next generation of neutrino oscillation experiments. In the coming decade, the DUNE and Hyper-Kamiokande experiments will be able to study the oscillation of both neutrinos and antineutrinos with unprecedented precision. We explore the ability of these experiments, and combinations of them, to determine whether the parameters that govern these oscillations are the same for neutrinos and antineutrinos, as prescribed by the C P T -theorem. We find that both DUNE and Hyper-Kamiokande will be sensitive to unexplored levels of leptonic C P T -violation. Assuming the parameters for neutrino and antineutrino oscillations are unrelated, we discuss the ability of these experiments to determine the neutrino and antineutrino mass-hierarchies, atmospheric-mixing octants, and C P -odd phases, three key milestones of the experimental neutrino physics program. Additionally, if the C P T -symmetry is violated in nature in a way that is consistent with all present neutrino and antineutrino oscillation data, we find that DUNE and Hyper-Kamiokande have the potential to ultimately establish leptonic C P T -invariance violation.

Isotope exchange reaction of tritium on precious metal catalyst based on cation-exchanged mordenite for blanket tritium recovery

Energy Technology Data Exchange (ETDEWEB)

Kawamura, Yoshinori, E-mail: kawamura.yoshinori@jaea.go.jp [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Hayashi, Takumi [Japan Atomic Energy Agency, 2-4 Shirane Shirakata, Tokai, Ibaraki 319-1195 (Japan); Yamanishi, Toshihiko [Japan Atomic Energy Agency, 2-166 Omotedate Obuchi, Rokkasho, Aomori 039-3212 (Japan)

2016-11-01

Highlights: • Precious metal catalyst based on cation-exchanged mordenite was prepared. • Isotope exchange reaction between H{sub 2} and HTO on the catalyst was investigated. • The order of entire reaction is not clear, but it is the first-order reaction as for HTO. • Effect of exchanged cation may appear as the difference of the surface area of catalyst. - Abstract: It is known that the chemical forms of tritium released from a ceramic breeder blanket are hydrogen form and water form. To recover tritiated water vapor, adoption of dryer that is packed column of synthetic zeolite has been proposed. On the other hand, synthetic zeolite is often used as a support of precious metal catalyst. Such catalysts usually have a capability of hydrogen isotope exchange between gas and water vapor. If this catalyst is used to dryer, the dryer may obtain a preferable function for tritium recovery by isotopic exchange reaction. To assess such functions, reaction rate should be estimated. The results of water adsorption experiment on cation-exchanged mordenite-type zeolite suggested the possibility that state of adsorbed water varied by exchanged cation. So, in this work, precious metal catalyst based on cation-exchanged mordenite was prepared, and the reaction rate of chemical exchange between hydrogen and tritiated water was investigated under temperature range between 30 °C and 80 °C by the steady-state approximation. In the case of platinum on Na-mordenite, the reaction between gaseous hydrogen and tritiated water vapor was almost expressed as first-order reaction concerning tritiated water vapor concentration.

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.

Determination of kinetic parameters of heterogeneous isotopic exchange reaction

International Nuclear Information System (INIS)

Huang, Ting-Chia; Tsai, Fuan-Nan

1977-01-01

A mathematical model has been proposed for a heterogeneous isotopic exchange reaction which involves film diffusion, surface chemical reaction and intraparticle diffusion. The exchange equation to predict the exchange fraction as a function of time for the spherical particles immersed in a solution of finite volume has been derived. The relations between the exchange fraction and dimensionless time are plotted with xi(=ak sub(f)/KD sub(e)), xi 1 (=K 1 a 2 /D sub(e)) and final fractional uptake as parameters. From the values of the kinetic parameters xi and xi 1 , the relative importance of each limiting step is discussed. Experimental results of the isotopic exchange reaction of calcium ion in both system CaCO 3 (s)/Ca 2+ (aq) and system calcium type resin Dowex 50W-X8/Ca 2+ (aq) are coincident with the theoretical equation proposed in this study. (auth.)

Hydrogen/Chlorine exchange reactions of gaseous carbanions.

Science.gov (United States)

Chen, Hao; Cooks, R Graham; Meurer, Eduardo C; Eberlin, Marcos N

2005-12-01

Gas-phase reactions of three typical carbanions CH(2)NO(2)(-), CH(2)CN(-), and CH(2)S(O)CH(3)(-) with the chloromethanes CH(2)Cl(2), CHCl(3), and CCl(4), examined by tandem mass spectrometry, show a novel hydrogen/chlorine exchange reaction. For example, reaction between the nitromethyl anion CH(2)NO(2)(-) and carbon tetrachloride CCl(4) forms the ion CHClNO(2)(-). The suggested reaction mechanism involves nucleophilic attack by CH(2)NO(2)(-) at the chlorine of CCl(4) followed by proton transfer within the resulting complex [CH(2)ClNO(2) + CCl(3)(-)] to form CHClNO(2)(-) and CHCl(3). Two other carbanions CH(2)CN(-) and CH(2)S(O)CH(3)(-) also undergo the novel hydrogen/chlorine exchange reactions with CCl(4) but to a much smaller extent, their higher nucleophilicities favoring competitive nucleophilic attack reactions. Proton abstraction is the exclusive pathway in the reactions of these carbanions with CHCl(3). While CH(2)CN(-) and CH(2)S(O)CH(3)(-) promote mainly proton abstraction and nucleophilic displacement in reactions with CH(2)Cl(2), CH(2)NO(2)(-) does not react.

Diffractive production of p-mesons and of pπ-systems by neutrinos and antineutrinos on protons

International Nuclear Information System (INIS)

Jones, G.T.; Jones, R.W.L.; Kennedy, B.W.; Morrison, D.R.O.; Borner, H.P.; Myatt, G.; Bullock, F.W.; Burke, S.

1993-01-01

Evidence is presented for diffractive production of ρ-mesons and of ρπ-systems in νp and anti νp charged-current interactions. In the (anti-)neutrino energy range 10 GeV ν 1 production. However, the data cannot distinguish between diffractive a 1 and diffractive nonresonant ρπ production. The experimental distributions of W, Q 2 , x Bj and y Bj for diffractive ρ and ρπ events are consistent with model predictions. (orig.)

Pion double charge exchange and hadron dynamics

International Nuclear Information System (INIS)

Johnson, M.B.

1991-01-01

This paper will review theoretical results to show how pion double charge exchange is contributing to our understanding of hadron dynamics in nuclei. The exploitation of the nucleus as a filter is shown to be essential in facilitating the comparison between theory and experiment. 23 refs., 3 figs., 2 tabs

Bibliography of integral charged particle nuclear data

International Nuclear Information System (INIS)

Holden, N.E.; Burrows, T.W.

1982-03-01

This publication is the second supplement to the archival edition of the National Nuclear Data Center's charged-particle bibliography. This supplement contains citations to all references scanned since March 15, 1981, and all corrections and additions to previous citations, and indexes all data received in the international exchanged format (EXFOR). The primary goal of the bibliography has been to satisfy the need expressed by the Nuclear Reaction Data Center Network for a concise and comprehensive bibliography of integral charged-particle cross section data and to provide an index of data exchanged among the members. In 1980, coverage was expanded to include differential data relevant to charged-particle-induced neutron-source reactions

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, M_A and the Pauli blocking scaling function, that matches the antineutrino NCE scattering data. However, the best fit values of M_A=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.

Kinetics of isotope exchange reactions involving intra- and intermolecular reactions: 1. Rate law for a system with two chemical compounds and three exchangeable atoms

International Nuclear Information System (INIS)

Xuelei Chu; Ohmoto, Hiroshi

1991-01-01

For an isotopic exchange reaction between two compounds (X and AB) in a homogeneous system, such as a gaseous or aqueous system, where one (AB) of them possesses two exchangeable atoms in non-equivalent positions and where one intramolecular isotope exchange (A ↔ B) and two intermolecular isotope exchange reactions (X ↔ A and X ↔ B) may occur, its rate law no longer obeys a pseudo-first order rate equation described for simple two-component systems by many previous investigators. The change with time of the δ value of each of the three components (X, A, and B) in a closed and homogeneous system is a complicated function of the initial δ values of the three components, the chemical concentrations of the two compounds, and the overall rate constants of the forward and reverse reactions involving the two intermolecular and one intramolecular reactions of isotope exchanges. Also, for some one of the three components, the change of its δ value with time may not be monotonic, and the relationship of 1n (1 - F) with time may be non-linear in a plot of 1n (1 - F) vs. t. In addition, the rate law of the isotope exchange reaction in this system also provides a quantitative method to estimate the overall rate constants for the one-intra-and two intermolecular isotope exchanges and the equilibrium isotopic fractionation factors among the three components

New analytic approach to the theory of charge exchange in atom-multiply charged ion collisions

International Nuclear Information System (INIS)

Presnyakov, L.P.; Uskov, D.B.; Janev, R.K.

1981-01-01

A new method is discussed for the solution of many-level charge-exchange problems. The results provide the distribution of the final electronic states over the angular quantum numbers in analytical form. The obtained Z oscillations (Z is the ion charge) of the cross sections are found to be in good agreement with recent experimental data. (orig.)

Isotope exchange reaction in uranous-uranyl-sulphuric acid system

International Nuclear Information System (INIS)

Ling Daren; Yue Tingsheng; Mu Dehai; Wang Yani

1990-01-01

The kinetics of the isotope exchange reaction between U(IV) and U(VI) has been studied in low concentrations of sulphuric acid. A minimum exchange rate appears at 0.25 M H 2 SO 4 . From the rates at different temperatures ranging from 20deg to 35deg C, an apparent activation energy of 86 kcal/mole was calculated. The exchange rate was found to be accelerated by the addition of ferrous ions, and a half-life of less than 1 s, was obtained. Probable mechanisms for the acceleration of the uranium isotope exchange reactions by acidity and ferrous ions are proposed. (orig.)

Quark jets from antineutrino interactions. 2. Inclusive particle spectra and multiplicities in the quark jets

International Nuclear Information System (INIS)

Ammosov, V.V.; Denisov, A.G.; Gapienko, G.S.

1981-01-01

The results on inclusive particle production in the antineutrino charged current induced hadron jets observed in the Fermilab 15- ft. bubble chamber are presented. Fractional energy distributions, particle ratios and average multiplicities of the hadrons in the jets are measured. Ratios between the inclusive production rates of different mesons in the jets are studied to seek evidence for the d-quark origin of the observed hadrons. Good over-all agreement with the hypothesis of d-quark fragmentation with universal fragmentation functions obeying isospin systematics is established [ru

Nucleon exchange properties of the E/A=8.5 MeV 74Ge+165Ho reaction

International Nuclear Information System (INIS)

Planeta, R.; Kwiatkowski, K.; Zhou, S.H.; Viola, V.E.; Breuer, H.; McMahan, M.A.; Kehoe, W.; Mignerey, A.C.

1990-01-01

Mass and charge distributions have been measured for damped projectile-like fragments in the reaction 74 Ge+ 165 Ho at 8.5 MeV per nucleon bombarding energy. Coincidences were measured between Z- and A-identified projectile-like fragments and angle-correlated heavy reaction partners in order to derive the primary mass distribution for projectile-like fragments. Centroids and variances of the primary and post-evaporative Z, N, and A distributions are presented. The evolution of the primary N and Z distributions as a function of energy loss is found to deviate from predictions of the nucleon exchange transport model

Comparing Positively and Negatively Charged Distonic Radical Ions in Phenylperoxyl Forming Reactions.

Science.gov (United States)

Williams, Peggy E; Marshall, David L; Poad, Berwyck L J; Narreddula, Venkateswara R; Kirk, Benjamin B; Trevitt, Adam J; Blanksby, Stephen J

2018-06-04

In the gas phase, arylperoxyl forming reactions play a significant role in low-temperature combustion and atmospheric processing of volatile organic compounds. We have previously demonstrated the application of charge-tagged phenyl radicals to explore the outcomes of these reactions using ion trap mass spectrometry. Here, we present a side-by-side comparison of rates and product distributions from the reaction of positively and negatively charge tagged phenyl radicals with dioxygen. The negatively charged distonic radical ions are found to react with significantly greater efficiency than their positively charged analogues. The product distributions of the anion reactions favor products of phenylperoxyl radical decomposition (e.g., phenoxyl radicals and cyclopentadienone), while the comparable fixed-charge cations yield the stabilized phenylperoxyl radical. Electronic structure calculations rationalize these differences as arising from the influence of the charged moiety on the energetics of rate-determining transition states and reaction intermediates within the phenylperoxyl reaction manifold and predict that this influence could extend to intra-molecular charge-radical separations of up to 14.5 Å. Experimental observations of reactions of the novel 4-(1-carboxylatoadamantyl)phenyl radical anion confirm that the influence of the charge on both rate and product distribution can be modulated by increasing the rigidly imposed separation between charge and radical sites. These findings provide a generalizable framework for predicting the influence of charged groups on polarizable radicals in gas phase distonic radical ions. Graphical Abstract.

Exchange reaction between tritiated hydrogen and water vapor

International Nuclear Information System (INIS)

Yamada, Koichi; Takano, Kenichi; Watanabe, Tamaki.

1979-01-01

Exchange reaction of tritiated hydrogen to water vapor under the condition of tritium gas concentration between 1 μCi/l and 1 mCi/l was studied. Tritium gas with hydrogen gas of 5 Torr and water of 20 mg were enclosed in a Pyrex glass ampule with volume of about 100 ml. The mixed gas with water vapor was heated with electric furnace. The heating time was between 2 and 100 hr, and the temperature was 776, 725, 675, 621, and 570.5 0 K. After heating, tritiated water was trapped with liquid nitrogen, and counted with a liquid scintillation counter. The radioactive concentration of initial tritiated hydrogen was measured with a calibrated ionization chamber. The main results obtained are as follows; 1) the concentration of produced tritiated water is well proportioned to that of initial tritiated hydrogen, 2) the activation energy of exchange reaction from tritiated hydrogen to tritiated water is 26.2 kcal/mol and that of inverse reaction is 27.4 kcal/mol, 3) the reaction rate at room temperature which calculated with activation energy is 1.04 x 10 -13 day -1 , and then exchange reaction at room temperature is negligible. (author)

Can one distinguish T-neutrinos from antineutrinos in neutral-current pion production processes?

OpenAIRE

Hernández Gajate, Eliecer; Nieves Pamplona, Juan Miguel; Valverde Hermosilla, Manuel

2007-01-01

A potential way to distinguish tau-neutrinos from antineutrinos, below the tau-production threshold, but above the pion production one, is presented. It is based on the different behavior of the neutral-current pion production off the nucleon, depending on whether it is induced by neutrinos or antineutrinos. This procedure for distinguishing tau-neutrinos from antineutrinos neither relies on any nuclear model, nor it is affected by any nuclear effect (distortion of the outgoing nucleon waves,...

Computational Approach to Electron Charge Transfer Reactions

DEFF Research Database (Denmark)

Jónsson, Elvar Örn

-molecular mechanics scheme, and tools to analyse statistical data and generate relative free energies and free energy surfaces. The methodology is applied to several charge transfer species and reactions in chemical environments - chemical in the sense that solvent, counter ions and substrate surfaces are taken...... in to account - which directly influence the reactants and resulting reaction through both physical and chemical interactions. All methods are though general and can be applied to different types of chemistry. First, the basis of the various theoretical tools is presented and applied to several test systems...... and asymmetric charge transfer reactions between several first-row transition metals in water. The results are compared to experiments and rationalised with classical analytic expressions. Shortcomings of the methods are accounted for with clear steps towards improved accuracy. Later the analysis is extended...

The Influence of Particle Charge on Heterogeneous Reaction Rate Coefficients

Science.gov (United States)

Aikin, A. C.; Pesnell, W. D.

2000-01-01

The effects of particle charge on heterogeneous reaction rates are presented. Many atmospheric particles, whether liquid or solid are charged. This surface charge causes a redistribution of charge within a liquid particle and as a consequence a perturbation in the gaseous uptake coefficient. The amount of perturbation is proportional to the external potential and the square of the ratio of debye length in the liquid to the particle radius. Previous modeling has shown how surface charge affects the uptake coefficient of charged aerosols. This effect is now included in the heterogeneous reaction rate of an aerosol ensemble. Extension of this analysis to ice particles will be discussed and examples presented.

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.)

Charge exchange cooling in the tandem mirror plasma confinement apparatus

Science.gov (United States)

Logan, B. Grant

1978-01-01

Method and apparatus for cooling a plasma of warm charged species confined in the center mirror cell of the tandem mirror apparatus by injecting cold neutral species of the plasma into at least one mirroring region of the center mirror cell, the cooling due to the loss of warm charged species through charge exchange with the cold neutral species with resulting diffusion of the warm neutral species out of the plasma.

An abnormally slow proton transfer reaction in a simple HBO derivative due to ultrafast intramolecular-charge transfer events.

Science.gov (United States)

Alarcos, Noemí; Gutierrez, Mario; Liras, Marta; Sánchez, Félix; Douhal, Abderrazzak

2015-07-07

We report on the steady-state, picosecond and femtosecond time-resolved studies of a charge and proton transfer dye 6-amino-2-(2'-hydroxyphenyl)benzoxazole (6A-HBO) and its methylated derivative 6-amino-2-(2'-methoxyphenyl)benzoxazole (6A-MBO), in different solvents. With femtosecond resolution and comparison with the photobehaviour of 6A-MBO, we demonstrate for 6A-HBO in solution, the photoproduction of an intramolecular charge-transfer (ICT) process at S1 taking place in ∼140 fs or shorter, followed by solvent relaxation in the charge transferred species. The generated structure (syn-enol charge transfer conformer) experiences an excited-state intramolecular proton-transfer (ESIPT) reaction to produce a keto-type tautomer. This subsequent proton motion occurs in 1.2 ps (n-heptane), 14 ps (DCM) and 35 ps (MeOH). In MeOH, it is assisted by the solvent molecules and occurs through tunneling for which we got a large kinetic isotope effect (KIE) of about 13. For the 6A-DBO (deuterated sample in CD3OD) the global proton-transfer reaction takes place in 200 ps, showing a remarkable slow KIE regime. The slow ESIPT reaction in DCM (14 ps), not through tunnelling as it is not sensitive to OH/OD exchange, has however to overcome an energy barrier using intramolecular as well as solvent coordinates. The rich ESIPT dynamics of 6A-HBO in the used solutions is governed by an ICT reaction, triggered by the amino group, and it is solvent dependent. Thus, the charge injection to a 6A-HBO molecular frame makes the ICT species more stable, and the phenol group less acidic, slowing down the subsequent ESIPT reaction. Our findings bring new insights into the coupling between ICT and ESIPT reactions on the potential-energy surfaces of several barriers.

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

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.

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

Heterogeneous Catalysis: Deuterium Exchange Reactions of Hydrogen and Methane

Science.gov (United States)

Mirich, Anne; Miller, Trisha Hoette; Klotz, Elsbeth; Mattson, Bruce

2015-01-01

Two gas phase deuterium/hydrogen exchange reactions are described utilizing a simple inexpensive glass catalyst tube containing 0.5% Pd on alumina through which gas mixtures can be passed and products collected for analysis. The first of these exchange reactions involves H[subscript 2] + D[subscript 2], which proceeds at temperatures as low as 77…

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.

Characteristics of solid-target charge-exchange analyzers for energetic ion diagnostics on tokamaks

International Nuclear Information System (INIS)

Beiersdorfer, P.; Roquemore, A.L.; Kaita, R.

1987-05-01

Compact electrostatic charge-exchange analyzers have been constructed for installation in areas of high magnetic fields and restricted access near tokamak fusion devices. The analyzers employed carbon stripping foils, and have been calibrated for proton energies between 1 and 70 keV. They have been successfully used to study charge-exchange losses in auxiliary-heated tokamak plasmas

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)

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

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

Nuclear data needs in nuclear astrophysics: Charged-particle reactions

International Nuclear Information System (INIS)

Smith, Michael S.

2001-01-01

Progress in understanding a diverse range of astrophysical phenomena - such as the Big Bang, the Sun, the evolution of stars, and stellar explosions - can be significantly aided by improved compilation, evaluation, and dissemination of charged-particle nuclear reaction data. A summary of the charged-particle reaction data needs in these and other astrophysical scenarios is presented, along with recommended future nuclear data projects. (author)

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.

Isotopic exchange reaction between barium ion and tri barium phosphate

International Nuclear Information System (INIS)

Bilgin, G.B.; Cetin, I.

1982-01-01

Heterogeneous exchange reaction of tri barium phosphate in barium chloride solution has been studied using 133 Ba as a tracer. The results show that the exchange fraction increases as barium chloride concentration increases for different mole ratio of the exchange ion on the solid surface and in the solution. The phenomenon was studied with respect to the previous treatment of the precipitate leading to different crystal sizes and the effect of reaction time. (author)

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

(p,. pi. /sup -/) reaction and. delta. /sup + +/ components of nuclei

Energy Technology Data Exchange (ETDEWEB)

Kisslinger, L S; Miller, G A [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

1975-12-08

The use of the (p,..pi../sup -/) reaction as a probe to determine ..delta../sup + +/(1232) components of nuclear wave functions is examined within the framework of a model which treats baryon resonances on the same footing as nucleons. Nuclear structure properties which affect the ..delta..-probability are discussed. Estimates of cross sections, at several energies, are made for the ..delta../sup + +/ transfer contribution as well as for the competing processes: proton charge exchange (p,n) followed by an (n,..gamma../sup -/) reaction; emission of a ..pi../sup 0/ followed by pion charge exchange (..pi../sup -/,..pi../sup 0/). Even with ..delta..-probabilities as small as 0.0001 the ..delta..-transfer process can compete with ordinary background charge-exchange reactions.

Samarium ion exchanged montmorillonite for high temperature cumene cracking reaction

International Nuclear Information System (INIS)

Binitha, N.N.

2009-01-01

Full text: Nano material Montmorillonite clay is cation exchanged with samarium and its catalytic influence in cumene cracking reaction is investigated. Effect of exchange with sodium ions on further exchange with samarium ions is also noted. Acidity measurements are done using TPD of ammonia. The retention of basic structure is proved from FTIR spectra and XRD patterns. Elemental analysis result shows that samarium exchange has occurred, which is responsible for the higher catalytic activity. Surface area and pore volume remains more or less unaffected upon exchange. Thermogravimetric analysis indicates the enhanced thermal stability on exchanging. Cumene cracking reaction is carried out at atmospheric pressure in a fixed bed glass reactor at 673 K. The predominance of Bronsted acidity is confirmed from high selectivity to benzene. (author)

Scaling Hydrologic Exchange Flows and Biogeochemical Reactions from Bedforms to Basins

Science.gov (United States)

Harvey, J. W.; Gomez-Velez, J. D.

2015-12-01

River water moves in and out of the main channel along pathways that are perpendicular to the channel's main axis that flow across or beneath the ground surface. These hydrologic exchange flows (HEFs) are difficult to measure, yet no less important than a river's downstream flow, or exchanges with the atmosphere and deeper groundwater (Harvey and Gooseff, 2015, WRR). There are very few comprehensive investigations of exchange fluxes to understand patterns with river size and relative importance of specific types of exchanges. We used the physically based model NEXSS to simulate multiple scales of hyporheic flow and their cumulative effects on solute reaction in large basins (on the order of Chesapeake Bay basin or larger). Our goal was to explain where and when particular types of hyporheic flow are important in enhancing key biogeochemical reactions, such as organic carbon respiration and denitrification. Results demonstrate that hyporheic flux (expressed per unit area of streambed) varies surprisingly little across the continuum of first-order streams to eighth-order rivers, and vertical exchange beneath small bedforms dominates in comparison with lateral flow beneath gravel bars and meanders. Also, the river's entire volume is exchanged many times with hyporheic flow within a basin, and the turnover length (after one entire river volume is exchanged) is strongly influenced by hydrogeomorphic differences between physiographic regions as well as by river size. The cumulative effects on biogeochemical reactions were assessed using a the reaction significance factor, RSF, which computes the cumulative potential for hyporheic reactions using a dimensionless index that balances reaction progress in a single hyporheic flow path against overall processing efficiency of river turnover through hyporheic flow paths of that type. Reaction significance appears to be strongly dominated by hydrologic factors rather than biogeochemical factors, and seems to be dominated by

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.)

Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes

Science.gov (United States)

Ma, X.; Fang, F.; Li, Q.; Zhu, J.; Yang, Y.; Wu, Y. Z.; Zhao, H. B.; Lüpke, G.

2015-10-01

Optical control of spin is of central importance in the research of ultrafast spintronic devices utilizing spin dynamics at short time scales. Recently developed optical approaches such as ultrafast demagnetization, spin-transfer and spin-orbit torques open new pathways to manipulate spin through its interaction with photon, orbit, charge or phonon. However, these processes are limited by either the long thermal recovery time or the low-temperature requirement. Here we experimentally demonstrate ultrafast coherent spin precession via optical charge-transfer processes in the exchange-coupled Fe/CoO system at room temperature. The efficiency of spin precession excitation is significantly higher and the recovery time of the exchange-coupling torque is much shorter than for the demagnetization procedure, which is desirable for fast switching. The exchange coupling is a key issue in spin valves and tunnelling junctions, and hence our findings will help promote the development of exchange-coupled device concepts for ultrafast coherent spin manipulation.

Asymmetric H-D exchange reactions of fluorinated aromatic ketones

KAUST Repository

Zhao, Yujun

2012-01-01

Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction\\'s stereoselectivity. © 2012 The Royal Society of Chemistry.

Apparent violation of the sum rule for exchange-correlation charges by generalized gradient approximations.

Science.gov (United States)

Kohut, Sviataslau V; Staroverov, Viktor N

2013-10-28

The exchange-correlation potential of Kohn-Sham density-functional theory, vXC(r), can be thought of as an electrostatic potential produced by the static charge distribution qXC(r) = -(1∕4π)∇(2)vXC(r). The total exchange-correlation charge, QXC = ∫qXC(r) dr, determines the rate of the asymptotic decay of vXC(r). If QXC ≠ 0, the potential falls off as QXC∕r; if QXC = 0, the decay is faster than coulombic. According to this rule, exchange-correlation potentials derived from standard generalized gradient approximations (GGAs) should have QXC = 0, but accurate numerical calculations give QXC ≠ 0. We resolve this paradox by showing that the charge density qXC(r) associated with every GGA consists of two types of contributions: a continuous distribution and point charges arising from the singularities of vXC(r) at each nucleus. Numerical integration of qXC(r) accounts for the continuous charge but misses the point charges. When the point-charge contributions are included, one obtains the correct QXC value. These findings provide an important caveat for attempts to devise asymptotically correct Kohn-Sham potentials by modeling the distribution qXC(r).

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

Development and Application of Ligand-Exchange Reaction Method ...

African Journals Online (AJOL)

Purpose: This paper presents an improved kinetic-spectrophotometric procedure for determining clonazepam (CZP) in pharmaceutical formulations and human serum. Methods: The method is based on ligand-exchange reaction. The reaction was followed spectrophotometrically by measuring the rate of change of ...

Bombarding energy dependence of nucleon exchange and energy dissipation in the strongly damped reaction 209Bi + 136Xe

International Nuclear Information System (INIS)

Wilcke, W.W.; Schroeder, W.U.; Huizenga, J.R.; Birkelund, J.R.; Randrup, J.

1980-01-01

Although considerable progress has been achieved in the understanding of strongly damped reactions at energies several MeV/u above the Coulomb barrier, some important experimental results are not yet clearly understood. Among these is the degree of correlation between the nucleon exchange and the large energy losses observed. Experimental evidence suggesting nucleon exchange as described by a one-body model to be the major component of the dissipation mechanism is discussed. It is concluded that the previously unexplained bombarding energy dependence between energy loss and fragment charge dispersion can be understood on the basis of a nucleon exchange model, provided the Pauli exclusion principle is taken into account. No necessity is seen to invoke further energy dissipation mechanisms. 7 figures

Experimental test of the PCAC-hypothesis in charged current neutrino and antineutrino interactions on protons

Science.gov (United States)

Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; O'Neale, S. W.; Klein, H.; Morrison, D. R. O.; Schmid, P.; Wachsmuth, H.; Miller, D. B.; Mobayyen, M. M.; Wainstein, S.; Aderholz, M.; Hoffmann, E.; Katz, U. F.; Kern, J.; Schmitz, N.; Wittek, W.; Allport, P.; Myatt, G.; Radojicic, D.; Bullock, F. W.; Burke, S.

1987-03-01

Data obtained with the bubble chamber BEBC at CERN are used for the first significant test of Adler's prediction for the neutrino and antineutrino-proton scattering cross sections at vanishing four-momentum transfer squared Q 2. An Extended Vector Meson Dominance Model (EVDM) is applied to extrapolate Adler's prediction to experimentally accessible values of Q 2. The data show good agreement with Adler's prediction for Q 2→0 thus confirming the PCAC hypothesis in the kinematical region of high leptonic energy transfer ν>2 GeV. The good agreement of the data with the theoretical predictions also at higher Q 2, where the EVDM terms are dominant, also supports this model. However, an EVDM calculation without PCAC is clearly ruled out by the data.

Experimental test of the PCAC-hypothesis in charged current neutrino and antineutrino interactions on protons

International Nuclear Information System (INIS)

Jones, G.T.; Jones, R.W.L.; Kennedy, B.W.; O'Neale, S.W.; Klein, H.; Morrison, D.R.O.; Schmid, P.; Wachsmuth, H.; Allport, P.; Myatt, G.; Radojicic, D.; Bullock, F.W.; Burke, S.

1987-01-01

Data obtained with the bubble chamber BEBC at CERN are used for the first significant test of Adler's prediction for the neutrino and antineutrino-proton scattering cross sections at vanishing four-momentum transfer squared Q 2 . An Extended Vector Meson Dominance Model (EVDM) is applied to extrapolate Adler's prediction to experimentally accessible values of Q 2 . The data show good agreement with Adler's prediction for Q 2 → 0 thus confirming the PCAC hypothesis in the kinematical region of high leptonic energy transfer ν > 2 GeV. The good agreement of the data with the theoretical predictions also at higher Q 2 , where the EVDM terms are dominant, also supports this model. However, an EVDM calculation without PCAC is clearly ruled out by the data. (orig.)

Charge exchange measurements on ISX-A

International Nuclear Information System (INIS)

Neilson, G.H.

1979-04-01

Apparatus and techniques for charge exchange neutral analysis on the ISX-A (Impurity Study Experiment) tokamak are described. A new neutral analyzer incorporating mass-energy resolution was constructed and calibrated for use on ISX. Data interpretation methods which account for profile effects and neutral attenuation have also been developed and were applied to data from the mass-energy analyzer. Examples of data from ISX-A are presented to illustrate both the use of this new instrument and the applicability of the described interpretation techniques

Enhancement of isotope exchange reactions over ceramic breeder material by deposition of catalyst metal

International Nuclear Information System (INIS)

Narisato, Y.; Munakata, K.; Koga, A.; Yokoyama, Y.; Takata, T.; Okabe, H.

2004-01-01

The deposition of catalyst metals in ceramic breeders could enhance the release rate of tritium due to the promotion of isotope exchange reactions taking place at the interface of the breeder surface and the sweep gas. In this work, the authors examined the effects of catalytic active metal deposited on lithium titanate on the isotope exchange reactions. With respect to the virgin lithium titanate, it was found that the rate of the isotope exchange reactions taking place on the surface is quite low. However, the deposition of palladium greatly increased the exchange reaction rate. The effect of the amounts of deposited palladium on the isotope exchange reaction rate was also investigated. The results indicate that the exchange reactions are still enhanced even if the amounts of deposited palladium are as low as 0.04%

Reference Cross Sections for Charged-particle Monitor Reactions

Science.gov (United States)

Hermanne, A.; Ignatyuk, A. V.; Capote, R.; Carlson, B. V.; Engle, J. W.; Kellett, M. A.; Kibédi, T.; Kim, G.; Kondev, F. G.; Hussain, M.; Lebeda, O.; Luca, A.; Nagai, Y.; Naik, H.; Nichols, A. L.; Nortier, F. M.; Suryanarayana, S. V.; Takács, S.; Tárkányi, F. T.; Verpelli, M.

2018-02-01

Evaluated cross sections of beam-monitor reactions are expected to become the de-facto standard for cross-section measurements that are performed over a very broad energy range in accelerators in order to produce particular radionuclides for industrial and medical applications. The requirements for such data need to be addressed in a timely manner, and therefore an IAEA coordinated research project was launched in December 2012 to establish or improve the nuclear data required to characterise charged-particle monitor reactions. An international team was assembled to recommend more accurate cross-section data over a wide range of targets and projectiles, undertaken in conjunction with a limited number of measurements and more extensive evaluations of the decay data of specific radionuclides. Least-square evaluations of monitor-reaction cross sections including uncertainty quantification have been undertaken for charged-particle beams of protons, deuterons, 3He- and 4He-particles. Recommended beam monitor reaction data with their uncertainties are available at the IAEA-NDS medical portal http://www-nds.iaea.org/medical/monitor_reactions.html.

Charge ordering and exchange bias behaviors in Co{sub 3}O{sub 4} porous nanoplatelets and nanorings

Energy Technology Data Exchange (ETDEWEB)

Debnath, J.C., E-mail: jcd341@uowmail.edu.au [Institute for Frontier Materials, Deakin University, Geelong, VIC 3216 (Australia); Wang, Jianli [Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia); Zeng, R. [Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia); School of Materials Science and Engineering, Faculty of Science, UNSW, Sydney NSW 2052 (Australia)

2017-01-01

We present the synthesis of α-Co{sub 3}O{sub 4} porous nanoplatelets and hexagonal nanorings using microwave-assisted hydrothermal and conventional chemical reaction methods. The x-ray diffraction (XRD) and refinement analyses indicate the α-Co{sub 3}O{sub 4} crystal structure, and the x-ray photoelectron spectrum (XPS) indicates the high purity of the samples. The M–T (including 1/χ–T) curves indicate an antiferromagnetic transition at about 35 K in both kind of samples but the interesting finding was made that a charge-ordered (CO) state appears at 250 K for the nanoplatelets sample whereas it is inattentive for the nanorings. The antiferromagnetic transition temperature T{sub N} is lower than that of the bulk α-Co{sub 3}O{sub 4} single crystal due to the nanosized structures. We observed quite significant exchange bias for nanorings. The exchange bias behavior of the α-Co{sub 3}O{sub 4} hexagonal nanorings is consistent with an antiferromagnetic (AFM) Co{sub 3}O{sub 4} core and spin-glass like shell. - Highlights: ●Charge-ordered state appears for the Co{sub 3}O{sub 4} nanoplatelets but absent for the nanorings. ●Quite significant exchange bias is only observed for Co{sub 3}O{sub 4} nanorings. ●Exchange bias behavior of Co{sub 3}O{sub 4} nanorings is consistent with spin-glass like shell. ●Potential for ultrahigh-density magnetic recording and spin valve devices.

Charged Porous Polymers using a Solid C-O Cross-Coupling Reaction

Energy Technology Data Exchange (ETDEWEB)

Zhang, Pengfei; Jiang, Xueguang; Wan, Shun; Dai, Sheng

2015-07-15

Here in this paper, we report a green, fast, efficient mechanochemical strategy for charged porous polymers (CPPs). A cationic CPP with basic anions and an anionic CPP with Li+ cations were fabricated by solid grinding under solvent-free conditions. Compared with solution-based synthesis, mechanochemical grinding can shorten the reaction time from dozens of hours to several minutes (60–90 min) to form polymers possessing a high molecular mass and low polydispersity. During the construction of CPPs, a Pd-catalyzed solid polycondensation based on unactivated organic linkers was introduced. In particular, CPPs with basic phenolic or proline anions showed good activity and stability in SO2 capture, and Li+-functionalized CPPs can be post-modified to CPPs with other metal ions by ion exchange, highlighting the tailorable feature of ionic-modified CPPs.

Charged Porous Polymers using a Solid C-O Cross-Coupling Reaction

Energy Technology Data Exchange (ETDEWEB)

Zhang, Pengfei; Jiang, Xueguang; Wan, Shun; Dai, Sheng

2015-07-15

Herein, we report a green, fast, efficient mechanochemical strategy for charged porous polymers (CPPs). A cationic CPP with basic anions and an anionic CPP with Li+ cations were fabricated by solid grinding under solvent-free conditions. Compared with solution-based synthesis, mechanochemical grinding can shorten the reaction time from dozens of hours to several minutes (60–90 min) to form polymers possessing a high molecular mass and low polydispersity. During the construction of CPPs, a Pd-catalyzed solid polycondensation based on unactivated organic linkers was introduced. In particular, CPPs with basic phenolic or proline anions showed good activity and stability in SO2 capture, and Li+-functionalized CPPs can be post-modified to CPPs with other metal ions by ion exchange, highlighting the tailorable feature of ionic-modified CPPs.

Study of electron anti-neutrinos associated with gamma-ray bursts using KamLAND

NARCIS (Netherlands)

Asakura, A.; Gando, A.; Gando, Y.; Hachiya, T.; Hayashida, S.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Ishikawa, T.; Ishio, S.; Koga, M.; Matsuda, S.; Mitsui, T.; Motoki, D.; Nakamura, K.; Obara, S.; Oki, Y.; Oura, T.; Shimizu, I.; Shirahata, Y.; Shirai, J.; Suzuki, A.; Tachibana, H.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B.D.; Yoshida, H.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Fushimi, K.; Piepke, A.; Banks, T.I.; Berger, B.E.; Fujikawa, B.K.; O'Donnell, T.; Learned, J.G.; Maricic, J.; Sakai, M.; Winslow, L.A.; Efremenko, Y.; Karwowski, H.J.; Markoff, D.M.; Tornow, W.; Detwiler, J.A.; Enomoto, S.; Decowski, M.P.

2015-01-01

We search for electron anti-neutrinos (-Ve) from long- and short-duration gamma-ray bursts (GRBs) using data taken by the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) from 2002 August to 2013 June. No statistically significant excess over the background level is found. We place the

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

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.)

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...

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.)

High resolution main-ion charge exchange spectroscopy in the DIII-D H-mode pedestal.

Science.gov (United States)

Grierson, B A; Burrell, K H; Chrystal, C; Groebner, R J; Haskey, S R; Kaplan, D H

2016-11-01

A new high spatial resolution main-ion (deuterium) charge-exchange spectroscopy system covering the tokamak boundary region has been installed on the DIII-D tokamak. Sixteen new edge main-ion charge-exchange recombination sightlines have been combined with nineteen impurity sightlines in a tangentially viewing geometry on the DIII-D midplane with an interleaving design that achieves 8 mm inter-channel radial resolution for detailed profiles of main-ion temperature, velocity, charge-exchange emission, and neutral beam emission. At the plasma boundary, we find a strong enhancement of the main-ion toroidal velocity that exceeds the impurity velocity by a factor of two. The unique combination of experimentally measured main-ion and impurity profiles provides a powerful quasi-neutrality constraint for reconstruction of tokamak H-mode pedestals.

Gamow Teller strength from charge exchange reactions at intermediate energies

International Nuclear Information System (INIS)

Haeusser, O.

1989-07-01

Detailed studies of the spin-isospin structure of nuclear excitations are possible at TRIUMF's medium resolution spectrometer using the (n,p), ( p → , p →/ ) and (p,n) reactions. We discuss here results on isospin symmetry of inelastic nucleon scattering reactions populating isospin triads in A=6 and A=12 nuclei. The β + Gamow Teller strength function from (n,p) reactions on (sd) and (fp) shell targets is found to be substantially quenched compared to current nuclear structure models using the free-nucleon axial-vector coupling constant. (Author) 22 refs., 3 figs

Charge exchange cooling in the tandem mirror plasma confinement apparatus

International Nuclear Information System (INIS)

Logan, B.G.

1978-01-01

A method and apparatus are described for cooling a plasma confined in the center mirror cell of the tandem mirror apparatus by injecting cold neutral species of the plasma into at least one mirroring region of the center mirror cell. The cooling is due to the loss of warm charged species through charge exchange with the cold neutral species with resulting diffusion of the warm neutral species out of the plasma

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

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.

Separation of uranium isotopes by accelerated isotope exchange reactions

International Nuclear Information System (INIS)

Seko, M.; Miyake, T.; Inada, K.; Ochi, K.; Sakamoto, T.

1977-01-01

A novel catalyst for isotope exchange reaction between uranium(IV) and uranium(VI) compounds enables acceleration of the reaction rate as much as 3000 times to make industrial separation of uranium isotopes economically possible

Short gamma ray bursts triggered by neutrino-antineutrino annihilation

Energy Technology Data Exchange (ETDEWEB)

Yasin, Hannah; Perego, Albino [Institut fuer Kernphysik, TU Darmstadt (Germany); Arcones, Almudena [Institut fuer Kernphysik, TU Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

2016-07-01

Gamma ray bursts (GRB) are one of the most energetic events in the universe. Neutron star mergers are the most favourable candidate for the subclass of GRBs that last less than two seconds. It has been suggested that the annihilation of neutrino-antineutrino pairs emitted by the hot and dense merger remnant could be enough to launch a relativistic jet, producing such a burst. We calculate the energy deposition by neutrino-antineutrino annihilation based on the results of a Newtonian simulation of the aftermath of a binary neutron star merger. In addition, we investigate the necessary requirements for launching a GRB and compare with our numerical results.

Kinetics of the high temperature oxygen exchange reaction on 238PuO2 powder

International Nuclear Information System (INIS)

Whiting, Christofer E.; Du, Miting; Felker, L. Kevin; Wham, Robert M.; Barklay, Chadwick D.; Kramer, Daniel P.

2015-01-01

Oxygen exchange reactions performed on PuO 2 suggest the reaction is influenced by at least three mechanisms: an internal chemical reaction, surface mobility of active species/defects, and surface exchange of gaseous oxygen with lattice oxygen. Activation energies for the surface mobility and internal chemical reaction are presented. Determining which mechanism is dominant appears to be a complex function including at least specific surface area and temperature. Thermal exposure may also impact the oxygen exchange reaction by causing reductions in the specific surface area of PuO 2 . Previous CeO 2 surrogate studies exhibit similar behavior, confirming that CeO 2 is a good qualitative surrogate for PuO 2 , in regards to the oxygen exchange reaction. Comparison of results presented here with previous work on the PuO 2 oxygen exchange reaction allows complexities in the previous work to be explained. These explanations allowed new conclusions to be drawn, many of which confirm the conclusions presented here. - Highlights: • PuO 2 Oxygen exchange kinetics can be influenced by at least 3 different mechanisms. • An internal chemical reaction controls the rate at high temperature and large SSA. • Surface mobility and surface exchange influence rate at lower temperatures and SSA. • Exchange temperatures may alter SSA and make data difficult to interpret.

Coherent scattering of neutrinos and antineutrinos by quarks in a crystal

International Nuclear Information System (INIS)

Weber, J.; Wilmot, G.

1988-01-01

An earlier paper presented the theory of a method for observation of neutrinos and antineutrinos. The method gives large cross sections. In this paper the theory is extended for a crystal with nuclei described by the modern theory of quarks. Results of experiments with a tritium antineutrino source, a nuclear reactor, and solar neutrinos are presented. Solar neutrinos lead to a positive result for the Eotvos experiment, for equal torsion balance masses composed of materials with different Debye temperatures

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

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

Light charged particle multiplicities in fusion and quasifission reactions

Science.gov (United States)

Kalandarov, Sh. A.; Adamian, G. G.; Antonenko, N. V.; Lacroix, D.; Wieleczko, J. P.

2018-01-01

The light charged particle evaporation from the compound nucleus and from the complex fragments in the reactions 32S+100Mo, 121Sb+27Al, 40Ar+164Dy, and 40Ar+ nat Ag is studied within the dinuclear system model. The possibility to distinguish the reaction products from different reaction mechanisms is discussed.

Asymmetric H-D exchange reactions of fluorinated aromatic ketones

KAUST Repository

Zhao, Yujun; Lim, XiaoZhi; Pan, Yuanhang; Zong, Lili; Feng, Wei; Tan, Choonhong; Huang, Kuo-Wei

2012-01-01

Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction's stereoselectivity. © 2012 The Royal Society of Chemistry.

Hydrogen isotope exchange reaction rates in tritium, hydrogen and deuterium mixed gases

International Nuclear Information System (INIS)

Uda, Tatsuhiko

1992-01-01

Hydrogen isotope exchange reaction rates in H 2 +T 2 , D 2 +T 2 and H 2 +D 2 +T 2 mixed gases, as induced by tritium decay and beta radiation, were experimentally measured by laser Raman spectrometry. Initially a glass cell was filled with T 2 gas to a pressure of 30-40 kPa, and an equivalent partial pressure of H 2 and/or D 2 was added. The first-order hydrogen isotope exchange reaction rates were 5.54x10 -2 h -1 for H 2 +T 2 mixed gas and 4.76x10 -2 h -1 for D 2 +T 2 . The actual HT producing rate was nearly equivalent to the rate of DT, but the reverse reaction rate of HT was faster than that of DT. The exchange reaction rates between H, D and T showed the isotope effect, HD>HT>DT. The hydrogen isotope exchange reaction rates observed were about twenty times larger than ion formation rates by beta radiation. This result suggests that a free radical chain reaction in hydrogen isotopes is occurring. (orig.)

Reactor antineutrino monitoring with a plastic scintillator array as a new safeguards method

OpenAIRE

Oguri, S.; Kuroda, Y.; Kato, Y.; Nakata, R.; Inoue, Y.; Ito, C.; Minowa, M.

2014-01-01

We developed a segmented reactor-antineutrino detector made of plastic scintillators for application as a tool in nuclear safeguards inspection and performed mostly unmanned field operations at a commercial power plant reactor. At a position outside the reactor building, we measured the difference in reactor antineutrino flux above the ground when the reactor was active and inactive.

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

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.

Selenocysteine in thiol/disulfide-like exchange reactions.

Science.gov (United States)

Hondal, Robert J; Marino, Stefano M; Gladyshev, Vadim N

2013-05-01

Among trace elements used as cofactors in enzymes, selenium is unique in that it is incorporated into proteins co-translationally in the form of an amino acid, selenocysteine (Sec). Sec differs from cysteine (Cys) by only one atom (selenium versus sulfur), yet this switch dramatically influences important aspects of enzyme reactivity. The main focus of this review is an updated and critical discussion on how Sec might be used to accelerate thiol/disulfide-like exchange reactions in natural selenoenzymes, compared with their Cys-containing homologs. We discuss in detail three major aspects associated with thiol/disulfide exchange reactions: (i) nucleophilicity of the attacking thiolate (or selenolate); (ii) electrophilicity of the center sulfur (or selenium) atom; and (iii) stability of the leaving group (sulfur or selenium). In all these cases, we analyze the benefits that selenium might provide in these types of reactions. It is the biological thiol oxidoreductase-like function that benefits from the use of Sec, since Sec functions to chemically accelerate the rate of these reactions. We review various hypotheses that could help explain why Sec is used in enzymes, particularly with regard to competitive chemical advantages provided by the presence of the selenium atom in enzymes. Ultimately, these chemical advantages must be connected to biological functions of Sec.

Kinetic study on ligand exchange reaction between EC and 99mTc-GH

International Nuclear Information System (INIS)

Wu Chunying; Luo Shineng; Fang Ping; Huang Heyun; Xie Minhao; Meng Hong

1995-01-01

The ligand exchange reaction between EC and 99m Tc-GH and its influence factors such as concentrations of EC and pH were described. The concentration of EC has no influence on the exchange reaction rate constant, while pH is the most important influence factor. The rate constants of ligand exchange reaction at different pH values were determined. The results showed that in order to make the labelling yield of 99m Tc-EC higher than 90%, pH of the reaction must be higher than 8

Interaction of low-energy highly charged ions with matter

International Nuclear Information System (INIS)

Ginzel, Rainer

2010-01-01

The thesis presented herein deals with experimental studies of the interaction between highly charged ions and neutral matter at low collision energies. The energy range investigated is of great interest for the understanding of both charge exchange reactions between ions comprising the solar wind and various astrophysical gases, as well as the creation of near-surface nanostructures. Over the course of this thesis an experimental setup was constructed, capable of reducing the kinetic energy of incoming ions by two orders of magnitude and finally focussing the decelerated ion beam onto a solid or gaseous target. A coincidence method was employed for the simultaneous detection of photons emitted during the charge exchange process together with the corresponding projectile ions. In this manner, it was possible to separate reaction channels, whose superposition presumably propagated large uncertainties and systematic errors in previous measurements. This work has unveiled unexpectedly strong contributions of slow radiative decay channels and clear evidence of previously only postulated decay processes in charge exchange-induced X-ray spectra. (orig.)

Exchange of charges between fast ions and neutral atoms; Change de charges entre ions rapides et atomes neutres

Energy Technology Data Exchange (ETDEWEB)

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

1955-07-01

In this paper, we summarize the most significant theoretical and experimental results obtained so far on the exchange of charges between fast ions and neutral atoms. (author) [French] Dans l'expose qui suit, nous resumons les resultats theoriques et experimentaux interessants obtenus jusqu'a nos jours dans le domaine de l'echange de charges entre ions rapides et atomes neutres. (auteur)

Light charged particle multiplicities in fusion and quasifission reactions

Energy Technology Data Exchange (ETDEWEB)

Kalandarov, Sh.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute of Nuclear Physics, Tashkent (Uzbekistan); Adamian, G.G. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Antonenko, N.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Tomsk Polytechnic University, Mathematical Physics Department, Tomsk (Russian Federation); Lacroix, D. [IN2P3-CNRS, Universite Paris-Sud, Institut de Physique Nucleaire, Orsay (France); Wieleczko, J.P. [GANIL, CEA et IN2P3-CNRS, Caen (France)

2018-01-15

The light charged particle evaporation from the compound nucleus and from the complex fragments in the reactions {sup 32}S + {sup 100}Mo, {sup 121}Sb + {sup 27}Al, {sup 40}Ar + {sup 164}Dy, and {sup 40}Ar + {sup nat}Ag is studied within the dinuclear system model. The possibility to distinguish the reaction products from different reaction mechanisms is discussed. (orig.)

Hydration shells exchange charge with their protein

DEFF Research Database (Denmark)

Abitan, Haim; Lindgård, Per-Anker; Nielsen, Bjørn Gilbert

2010-01-01

. In our experiments, the amplitude of an ultrasonic pressure wave is gradually increased (0–20 atm) while we simultaneously measure the Raman spectra from the hydrated protein (β-lactoglobulin and lysozyme). We detected two types of spectral changes: first, up to 70% increase in the intensity......Investigation of the interaction between a protein and its hydration shells is an experimental and theoretical challenge. Here, we used ultrasonic pressure waves in aqueous solutions of a protein to explore the conformational states of the protein and its interaction with its hydration shells...... the presence of an ultrasonic pressure, a protein and its hydration shells are in thermodynamic and charge equilibrium, i.e. a protein and its hydration shells exchange charges. The ultrasonic wave disrupts these equilibria which are regained within 30–45 min after the ultrasonic pressure is shut off....

Exchange reaction between hydrogen and deuterium. I. Importance of surface reactions in the steady-state mechanism

Energy Technology Data Exchange (ETDEWEB)

Marteau, C; Gaillard-Cusin, F; James, H [Centre National de la Recherche Scientifique, 45 - Orleans-la-Source (France). Centre de Recherches sur la Chimie de Combustion et des Hautes Temperatures

1978-05-01

Investigation of heterogeneous initiation process of gas phase linear chain reactions is carried out through the study of H/sub 2/-D/sub 2/ exchange reaction. Experimental data under study concern mainly the stationary rate of HD formation and the prestationary proceeding. Steady-state method accounts for the first one of these data; it allows to clearly compare the wall process part to the part played by the homogeneous chain reaction towards HD formation. Activation energy of exchange elementary step between chemisorbed hydrogen (on silica) and gaseous deuterium has been evaluated: Esub(e1)=52+-1 Kcal/mole.

Investor Reaction to Mandatory Offers on the Warsaw Stock Exchange

Directory of Open Access Journals (Sweden)

Szymon Okoń

2012-06-01

Full Text Available The following paper aims to assess investor reaction to mandatory offers on the Warsaw Stock Exchange, which is important because knowledge about these reactions can be used to make better investment decisions. This paper highlights the importance of procedure in making a mandatory offer and its grounds in the Polish legal system. Additionally, it presents empirical research on the reactions of investors to mandatory offers on the Warsaw Stock Exchange. It has been provided that mandatory offers have a significant impact on the price of a company’s shares listed on the Warsaw Stock Exchange. Knowledge about the reactions of investors to a mandatory offer may be used when selecting securities for an investment portfolio. The findings may provide guidance in deciding whether to begin or end investment in the company, both for individual and institutional investors. The event study methodology approach used in the paper is regarded as valuable and can be the basis for further research in other areas of the capital market research, especially in the context of information efficiency.

Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center

DEFF Research Database (Denmark)

Katona, Gergely; Snijder, Arjan; Gourdon, Pontus Emanuel

2005-01-01

In bright light the photosynthetic reaction center (RC) of Rhodobacter sphaeroides stabilizes the P(+)(870).Q(-)(A) charge-separated state and thereby minimizes the potentially harmful effects of light saturation. Using X-ray diffraction we report a conformational change that occurs within the cy...... the cytoplasmic domain of this RC in response to prolonged illumination with bright light. Our observations suggest a novel structural mechanism for the regulation of electron transfer reactions in photosynthesis....

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

Collective charge and mass transfer in heavy ion reactions

International Nuclear Information System (INIS)

Hahn, J.

1982-01-01

In this thesis the dynamics of the charge and mass asymmetry degree of freedom was studied in the framework of the fragmentation theory by means of a time-dependent Schroedinger equation. New is the introduction of a friction potential which describes the coupling of these collective degrees of freedom to the not explicitely treated other collective respectively internal degrees of freedom. Thereby it was shown that the measured widths of the isobaric charge distributions in the 86 Kr+sup(92,98)Mo reaction can be explained mainly by the quantum mechanical uncertainty in the charge asymmetry degree of freedom. The charge equilibration occurring at the begin of a deep inelastic collision can therefore by considered as a quantum mechanical, collective, damped motion which is connected with the excitation of the isovector giant dipole resonance of the nucleus-nucleus system. The study of the mass transfer in the reactions 132 Xe+ 120 Sn and 86 Kr+ 166 Er shows, how important at the begin of a deep inelastic collision shell structures and their conservation are for a large part of the reaction, even if the elemental distribution show no maxima in the region of magic shell closures. The experimental width are up to 10 MeV/A well described under conservation of the shell structure. (orig./HSI) [de

Detector of reactor antineutrinos with plastic scintillation bars

International Nuclear Information System (INIS)

Georgadze, A.Sh.; Pavlovich, V.M.

2015-01-01

Project of a segmented antineutrino detector is developed with the use of plastic scintillator rectangular bars 10 x 10 x 100 cm, wrapped in Gd foils and assembled to an array of 1 m3 active volume. The scintillation array is sandwiched at both sides by the continuous light guides of 100 x 100 x 10 cm size, from which the scintillation light is spreading simultaneously through continuous light guides between all photomultipliers, forming the specific Light Response Function (LRF), which is character to a certain nuclear event in detector. Analysis of LRF allows one effectively reject background events, providing high efficiency detection of antineutrino capture in the detector. Monte Carlo simulations with the help of MCNP and ZEMAX software show that with the use of selection criteria the neutrino events are well separated from the background

Experimental results on one-pion neutral current reaction in all channels induced by antineutrinos at CERN PS

CERN Document Server

Erriquez, O; Bullock, F W; Cavalli, D; Engel, J P; Fogli-Muciaccia, M T; Gamba, D; Guyonnet, J L; Halsteinslid, A; Henderson, R C W; Huss, D; Jones, T W; Marzari-Chiesa, A; Myklebost, K; Natali, S; Nuzzo, S; Paty, M; Pullia, A; Riccati, L; Riester, J L; Rognebakke, A; Rollier, M; Romero, A

1980-01-01

Single pion production, in antineutrino-nucleon interactions via the neutral current, has been studied in the bubble chamber Gargamelle, filled with propane. Complete analysis of the secondaries, including pi /sup 0/'s, has allowed a detailed study of all channels. After background and nuclear corrections, results are obtained which can be interpreted in terms of isospin structure of the neutral weak current and of the Salam-Weinberg angle. Agreement is found with the currently accepted value of sin/sup 2/ theta /sub w/ and the data suggest an important contribution of I=/sup 3///sub 2/ final states. (11 refs).

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)

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.

A search for neutrino–antineutrino mass inequality by means of sterile neutrino oscillometry

Energy Technology Data Exchange (ETDEWEB)

Smirnov, M.V., E-mail: gear8mike@gmail.com [Department of Physics, University of Jyväskylä, 40014 Jyväskylä (Finland); St. Petersburg State University, 198504 Peterhof, St. Petersburg (Russian Federation); Loo, K.K. [Department of Physics, University of Jyväskylä, 40014 Jyväskylä (Finland); Novikov, Yu.N. [St. Petersburg State University, 198504 Peterhof, St. Petersburg (Russian Federation); Petersburg Nuclear Physics Institute, 188300 Gatchina, St. Petersburg (Russian Federation); Trzaska, W.H. [Department of Physics, University of Jyväskylä, 40014 Jyväskylä (Finland); Wurm, M. [Johannes Gutenberg University Mainz, 55099 Mainz (Germany)

2015-11-15

The investigation of the oscillation pattern induced by the sterile neutrinos might determine the oscillation parameters, and at the same time, allow to probe CPT symmetry in the leptonic sector through neutrino–antineutrino mass inequality. We propose to use a large scintillation detector like JUNO or LENA to detect electron neutrinos and electron antineutrinos from MCi electron capture or beta decay sources. Our calculations indicate that such an experiment is realistic and could be performed in parallel to the current research plans for JUNO and RENO. Requiring at least 5σ confidence level and assuming the values of the oscillation parameters indicated by the current global fit, we would be able to detect neutrino–antineutrino mass inequality of the order of 0.5% or larger, which would imply a signal of CPT anomalies.

Nuclear attenuation of fast hadrons produced in charged-current ν and anti ν interactions in neon

International Nuclear Information System (INIS)

Burkot, W.; Coghen, T.; Czyzewski, J.

1996-01-01

The production of hadrons in charged-current (anti)neutrino interactions is studied with the bubble chamber BEBC exposed to the CERN (anti)neutrino wide-band beam. Fast-hadron production in a neon target is found to be attenuated as compared to that in a hydrogen target. This feature is discussed within theoretical models based on the idea of a hadron formation length. The experimental results favour the 'constituent' over the 'yo-yo' length concept, and suggest a quark cross section in the order of 3 mb. (orig.)

Design and calibration of a fast-time resolution charge exchange analyzer

International Nuclear Information System (INIS)

Scime, E.; Hokin, S.

1992-04-01

A five channel, fast time resolution, scanning charge exchange analyzer has been developed for the Madison Symmetric Torus (MST). The analyzer consists of an iron vacuum vessel, a gas stripping cell, an electrostatic bending field, and five continuous electron multiplier detectors. The incident neutral flux and operation of the detectors in current mode limits the time resolution of the analyzer to 10 μs. The analyzer was absolutely calibrated over the energy range of interest (500--2000 eV) with an H + beam, so that the charge exchange power loss could also be measured. The analyzer can be swiveled on a shot-to-shot basis for measurements of T i (r), where 0.3 < r/a < 0.7. The mechanical design was driven by the need for a low cost, expandable ion temperature diagnostic

Conferring specificity in redox pathways by enzymatic thiol/disulfide exchange reactions.

Science.gov (United States)

Netto, Luis Eduardo S; de Oliveira, Marcos Antonio; Tairum, Carlos A; da Silva Neto, José Freire

2016-01-01

Thiol-disulfide exchange reactions are highly reversible, displaying nucleophilic substitutions mechanism (S(N)2 type). For aliphatic, low molecular thiols, these reactions are slow, but can attain million times faster rates in enzymatic processes. Thioredoxin (Trx) proteins were the first enzymes described to accelerate thiol-disulfide exchange reactions and their high reactivity is related to the high nucleophilicity of the attacking thiol. Substrate specificity in Trx is achieved by several factors, including polar, hydrophobic, and topological interactions through a groove in the active site. Glutaredoxin (Grx) enzymes also contain the Trx fold, but they do not share amino acid sequence similarity with Trx. A conserved glutathione binding site is a typical feature of Grx that can reduce substrates by two mechanisms (mono and dithiol). The high reactivity of Grx enzymes is related to the very acid pK(a) values of reactive Cys that plays roles as good leaving groups. Therefore, although distinct oxidoreductases catalyze similar thiol–disulfide exchange reactions, their enzymatic mechanisms vary. PDI and DsbA are two other oxidoreductases, but they are involved in disulfide bond formation, instead of disulfide reduction, which is related to the oxidative environment where they are found. PDI enzymes and DsbC are endowed with disulfide isomerase activity, which is related with their tetra-domain architecture. As illustrative description of specificity in thiol-disulfide exchange, redox aspects of transcription activation in bacteria, yeast, and mammals are presented in an evolutionary perspective. Therefore, thiol-disulfide exchange reactions play important roles in conferring specificity to pathways, a required feature for signaling.

Relative mobility of 1-H atoms of carbohydrates in heterogeneous isotope exchange reactions

International Nuclear Information System (INIS)

Akulov, G.P.; Snetkova, E.V.; Kayumov, V.G.; Kaminskii, Yu.L.

1988-01-01

The method of competitive reactions was used to determine the relative mobilities of the 1-H atoms of carbohydrates in reactions of heterogeneous isotope exchange, using various reference standards, catalysts, and buffer systems. On the basis of the results obtained, the investigated carbohydrates are ranged in a series of decreasing mobility of the hydrogen atoms exchanged in heterogeneous isotope exchange reactions. It was demonstrated that the mobility of the 1-H atoms is related to the concentration of the acyclic forms of the carbohydrates

Mechanistic study of the isotopic-exchange reaction between gaseous hydrogen and palladium hydride powder

International Nuclear Information System (INIS)

Outka, D.A.; Foltz, G.W.

1991-01-01

A detailed mechanism for the isotopic-exchange reaction between gaseous hydrogen and solid palladium hydride is developed which extends previous model for this reaction by specifically including surface reactions. The modeling indicates that there are two surface-related processes that contribute to the overall rate of exchange: the desorption of hydrogen from the surface and the exchange between surface hydrogen and bulk hydrogen. This conclusion is based upon measurements examining the effect of small concentrations of carbon monoxide were helpful in elucidating the mechanism. Carbon monoxide reversibly inhibits certain steps in the exchange; this slows the overall rate of exchange and changes the distribution of products from the reactor

Limits on the electron-antineutrino mass

International Nuclear Information System (INIS)

Wilkerson, J.F.

1987-01-01

New measurements near the endpoint of the tritium beta-decay spectrum are producing limits on the electron-antineutrino mass which are below the central mass value of 30 eV reported by ITEP. The factors that influence the neutrino mass sensitivity of tritium beta decay measurements will be discussed followed by a review of the current experimental results. 9 refs., 5 figs., 2 tabs

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

Ion temperatures in HIP-1 and SUMMA from charge-exchange neutral optical emission spectra

Science.gov (United States)

Patch, R. W.; Lauver, M. R.

1976-01-01

Ion temperatures were obtained from observations of the H sub alpha, D sub alpha, and He 587.6 nm lines emitted from hydrogen, deuterium, and helium plasmas in the SUMMA and HIP-1 mirror devices at Lewis Research Center. Steady state discharges were formed by applying a radially inward dc electric field between cylindrical or annular anodes and hollow cathodes located at the peaks of the mirrors. The ion temperatures were found from the Doppler broadening of the charge-exchange components of spectral lines. A statistical method was developed for obtaining scaling relations of ion temperature as a function of current, voltage, and magnetic flux density. Derivations are given that take into account triangular monochromator slit functions, loss cones, and superimposed charge-exchange processes. In addition, the Doppler broadening was found to be sensitive to the influence of drift on charge-exchange cross section. The effects of finite ion-cyclotron radius, cascading, and delayed emission are reviewed.

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%)

Study of reactions of isotopic exchange of trans-zeatin with tritium

International Nuclear Information System (INIS)

Sidorov, G.V.; Myasoedov, N.F.

2006-01-01

Reactions of isotopic exchange of trans-zeatin with high-radioactive tritium water, with gaseous tritium in solution and solid-phase catalytic hydrogenation are studied to prepare trans-zeatin and dihydrozeatin labelled with tritium. It is shown that reaction of isotopic exchange of trans-zeatin with gaseous tritium both in solutions and without solvents at 160 Deg C and above leads to practically total hydrogenation of initial compound with formation of dihydrozeatin labelled with tritium. Isotopic exchange with tritium water permits to prepare zeatin labelled with tritium with 67 % yield and specific radioactivity 0.68 PBq/mol. It is determined that in the case of solid-phase isotopic exchange within 150-155 Deg C temperature interval both dihydrozeatin and trans-zeatin labelled with tritium are formed [ru

Resonant charge exchange for H-H+ in Debye plasmas

Science.gov (United States)

Laricchiuta, Annarita; Colonna, Gianpiero; Capitelli, Mario; Kosarim, Alexander; Smirnov, Boris M.

2017-11-01

The dynamics of resonant charge exchange in proton-hydrogen collisions embedded in plasma is investigated in the framework of the asymptotic approach, modified to account for the effect of Debye-Hückel screening in particle interactions. The cross sections exhibit a marked dependence on the Debye length in regimes of severe plasma confinement. Processes involving excited states H( n)-H+ are also discussed.

Neutron radiative capture reactions on nuclei of relevance to 0νββ, dark matter and neutrino/antineutrino searches

OpenAIRE

Tornow W.; Bhike Megha

2015-01-01

A program is underway at the Triangle Universities Nuclear Laboratory (TUNL) to measure the neutron capture cross section in the 0.5 to 15 MeV energy range on nuclei whose radioactive daughters could potentially create backgrounds in searches for rare events. Here, we refer to neutrino-less double-beta decay and dark-matter searches, and to detectors built for neutrino and/or antineutrino studies. Neutron capture cross-section data obtained by using the activation method are reported for 40Ar...

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

Isovector couplings for nucleon charge-exchange reactions at intermediate energies

International Nuclear Information System (INIS)

Love, W.G.; Nakayama, K.; Franey, M.A.

1987-01-01

The isovector parts of the effective nucleon-nucleon interaction are studied by examination of the reaction /sup 14/C(p,n) at intermediate energies near zero momentum transfer with use of recently developed G-matrix and free--t-matrix interactions. The spin-independent coupling (V/sub tau/) exhibits a strong energy and density dependence which, in the case of the G matrix based on the Bonn potential, significantly improves the agreement between calculated values of chemical bondV/sub σ//sub tau//V/sub tau/chemical bond 2 at q = 0 and those recently extracted from the reaction /sup 14/C

Charge exchange with ion excitation: asymptotic theory

International Nuclear Information System (INIS)

Ivakin, I.A.; Karbovanets, M.I.; Ostrovskii, V.N.

1987-01-01

There is developed an asymptotic (with respect to the large internuclear separation R) theory for computing the matrix element of the exchange interaction between states of quasimolecules, which is responsible for charge transfer with ion excitation: B + +A→B+A + *. A semiclassical approximation is used, which enables one to apply the theory to processes with the participation of multiply charged ions. The case of s--s transitions for excitation of the ion A + →A + *, where it is appropriate to take into account the distortion of the wave functions of the ion A + by the particle B, is treated separately. Calculations of cross sections and comparison with the results of experiments for He + --Cd and Ne + --Mg collisions at thermal energies are given. It is shown that it is impossible to explain the experimental data by the interaction of terms of the quasimolecules at large R only, and a possible mechanism for populating at small R is proposed

Study of Anti-Neutrino Beam with Muon Monitor in the T2K experiment

Science.gov (United States)

Hiraki, Takahiro

The T2K experiment is a long-baseline neutrino oscillation experiment. In 2013, the T2K collaboration observed electron neutrino appearance in a muon neutrino beam at 7.3 sigma significance. One of the next main goals of the T2K experiment is to measure electron anti-neutrino appearance. In June 2014 we took anti-neutrino beam data for the first time. The anti-neutrino beam was obtained by reversing the polarity of horn focusing magnets. To monitor the direction and intensity of the neutrino beam which is produced from the decay of pions and kaons, the muon beam is continuously measured by Muon Monitor (MUMON). To reconstruct the profile of the muon beam, MUMON is equipped with 49 sensors distributed on a plane behind the beam dump. In this report, we show some results of the anti-neutrino beam data taken by monitors including MUMON. In particular, dependence of the muon beam intensity on electric current of the horns, correlation between the proton beam position and the MUMON profile, and beam stability are presented. Comparison between the data and Monte Carlo simulation is also discussed.

Study of anti-neutrino beam with Muon Monitor in the T2K experiment

International Nuclear Information System (INIS)

Hiraki, Takahiro

2015-01-01

The T2K experiment is a long-baseline neutrino oscillation experiment. In 2013, the T2K collaboration observed electron neutrino appearance in a muon neutrino beam at 7.3 sigma significance. One of the next main goals of the T2K experiment is to measure electron anti-neutrino appearance. In June 2014 we took anti-neutrino beam data for the first time. The anti-neutrino beam was obtained by reversing the polarity of horn focusing magnets. To monitor the direction and intensity of the neutrino beam which is produced from the decay of pions and kaons, the muon beam is continuously measured by Muon Monitor (MUMON). To reconstruct the profile of the muon beam, MUMON is equipped with 49 sensors distributed on a plane behind the beam dump. In this report, we show some results of the anti-neutrino beam data taken by monitors including MUMON. In particular, dependence of the muon beam intensity on electric current of the horns, correlation between the proton beam position and the MUMON profile, and beam stability are presented. Comparison between the data and Monte Carlo simulation is also discussed. (author)

Application of tracer isotope in kinetic study of first order ion exchange reaction

International Nuclear Information System (INIS)

Lokhande, R.S.; Singare, P.U.

1998-01-01

Analysis of first order ion exchange reaction rates at different temperatures (27 deg- 48 degC) and particularly at low concentration of potassium iodide solution (electrolyte) ranging from 0.005 M to 0.040 M is carried out by application of radioactive tracer isotope 131 I. With increase in concentration of electrolyte, amount of iodide ion exchanged in millimoles increases. Specific reaction rates of ion exchange reaction are calculated for different temperatures and for different amount of ion exchange resins. It is observed that with increase in temperature, reaction rate increases but the increase is more pronounced for increase in amount of ion exchange resins. For 0.005 M solution of electrolyte, the reaction rate increases from 0.121 min -1 at 27 degC to 0.178 min -1 at 48 degC. For 0.005 M solution of electrolyte the reaction rate increases from 0.121 min -1 at 27 degC to 0.178 min 1 at 48 degC. For 0.005 M solution of electrolyte at 27 degC the reaction rate increases from 0.121 min -1 for 1.0 g of resin to 0.368 min -1 for 5.0 g of resin. From the reaction rates calculated at different temperatures, energy of activation in kJ/mole is calculated. It is observed that for 0.005 M solution of electrolyte, energy of activation is 4.62 kJ/mole which decreases to 2.87 kJ/mole for increase in concentration of electrolyte to 0.100 M. (author)

Measurement of the left-right asymmetry in pion-proton radiative exchange and charge exchange scattering from 301 to 625 MeV/c on a transversely polarized target

International Nuclear Information System (INIS)

Kim, George Jung-Kwang.

1988-05-01

The left-right asymmetry A/sub N/ in π/sup /minus//p → γn has been measured at p/sub π = 301, 316, 427, 471, 547, 586, and 625 MeV/c using a transversely polarized target. The final-state neutron and gamma were detected in coincidence by two states of matching neutron and gamma detectors at gamma angles centered around 90/degree and 110/degree/ c.m. A gamma detector consisted of an array of 15 counters, each was 15/times/15/times/25 cm 3 block of lead-glass. A neutron detector consisted of 15 counters also, each one was a cylindrical plastic scintillator 7.6 cm in diameter and 45.7 cm long. The A/sub N/ results are compared with the predictions from the most recent single-pion photoproduction partial-wave analysis by Arai and Fujii. The agreement is poor, casting doubt on the correctness of the value for the radiative-decay amplitude of the neutral Roper resonance now in use. A comparison is made with the 90/degree/recoil proton polarization data of the inverse reaction derived from γd scattering, there are substantial discrepencies. Charge exchange (π/sup /minus/p/ → γ/degree/n) events were the major yield in this experiment. Very precise values of the charge exchange analyzing power were obtained with an error of typically 3%. The charge exchange results are compared with the predictions from recent γn partial wave analyses. At the lower incident energies little difference is seen between the VPI, Karlsruhe-Helsinki, and CMU-LBL analyses, and there is excellent agreement with our experiment. From the onset of the Roper resonance the VPI solution is strongly favored

Quantum theory of exchange reactions: Use of nonorthogonal bases and coordinates

International Nuclear Information System (INIS)

Stechel, E.B.; Schmalz, T.G.; Light, J.C.

1979-01-01

A general approach to quantum scattering theory of exchange reactions utilizing nonorthogonal (''over-complete'') basis sets and nonorthogonal coordinates is presented. The method is shown to resolve many of the formal and practical difficulties attending earlier theories. Although the inspiration came from the early and accurate work on the collinear H+H 2 reaction by Diestler possible applications include electron transfer processes as well as chemical exchange reactions. The mathematics is formulated in detail and the solution is presented in terms of the R-matrix propagation method preserving all the symmetries of the physical process, i.e., conservation of flux and microscopic reversibility

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.

Kinetics of the high temperature oxygen exchange reaction on {sup 238}PuO{sub 2} powder

Energy Technology Data Exchange (ETDEWEB)

Whiting, Christofer E., E-mail: chris.whiting@udri.udayton.edu [University of Dayton – Research Institute, 300 College Park, Dayton, OH 45469-0172 (United States); Du, Miting; Felker, L. Kevin; Wham, Robert M. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Barklay, Chadwick D.; Kramer, Daniel P. [University of Dayton – Research Institute, 300 College Park, Dayton, OH 45469-0172 (United States)

2015-12-15

Oxygen exchange reactions performed on PuO{sub 2} suggest the reaction is influenced by at least three mechanisms: an internal chemical reaction, surface mobility of active species/defects, and surface exchange of gaseous oxygen with lattice oxygen. Activation energies for the surface mobility and internal chemical reaction are presented. Determining which mechanism is dominant appears to be a complex function including at least specific surface area and temperature. Thermal exposure may also impact the oxygen exchange reaction by causing reductions in the specific surface area of PuO{sub 2}. Previous CeO{sub 2} surrogate studies exhibit similar behavior, confirming that CeO{sub 2} is a good qualitative surrogate for PuO{sub 2}, in regards to the oxygen exchange reaction. Comparison of results presented here with previous work on the PuO{sub 2} oxygen exchange reaction allows complexities in the previous work to be explained. These explanations allowed new conclusions to be drawn, many of which confirm the conclusions presented here. - Highlights: • PuO{sub 2} Oxygen exchange kinetics can be influenced by at least 3 different mechanisms. • An internal chemical reaction controls the rate at high temperature and large SSA. • Surface mobility and surface exchange influence rate at lower temperatures and SSA. • Exchange temperatures may alter SSA and make data difficult to interpret.

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.

A Search for Electron Antineutrinos Associated with Gravitational-wave Events GW150914 and GW151226 Using KamLAND

Science.gov (United States)

Gando, A.; Gando, Y.; Hachiya, T.; Hayashi, A.; Hayashida, S.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Karino, Y.; Koga, M.; Matsuda, S.; Mitsui, T.; Nakamura, K.; Obara, S.; Oura, T.; Ozaki, H.; Shimizu, I.; Shirahata, Y.; Shirai, J.; Suzuki, A.; Takai, T.; Tamae, K.; Teraoka, Y.; Ueshima, K.; Watanabe, H.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Fushimi, K.; Piepke, A.; Banks, T. I.; Berger, B. E.; Fujikawa, B. K.; O'Donnell, T.; Learned, J. G.; Maricic, J.; Sakai, M.; Winslow, L. A.; Krupczak, E.; Ouellet, J.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Decowski, M. P.; KamLAND Collaboration

2016-10-01

We present a search, using KamLAND, a kiloton-scale anti-neutrino detector, for low-energy anti-neutrino events that were coincident with the gravitational-wave (GW) events GW150914 and GW151226, and the candidate event LVT151012. We find no inverse beta-decay neutrino events within ±500 s of either GW signal. This non-detection is used to constrain the electron anti-neutrino fluence and the total integrated luminosity of the astrophysical sources.

Study of transverse momenta of charged hadrons produced in ν p andbar vp charged current interactions

Science.gov (United States)

Jones, G. T.; Kennedy, B. W.; Middleton, R. P.; O'Neale, S. W.; Cooper, A. M.; Grant, A.; Klein, H.; Mittendorfer, J.; Morrison, D. R. O.; Parker, A.; Schmid, P.; Wachsmuth, H.; Hamisi, F.; Mobayyen, M. M.; Villalobos-Baillie, O.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Retter, M.

1984-06-01

Data from a neutrino and antineutrino hydrogen experiment with BEBC are used to investigate transverse properties of the produced charged hadrons. Measurements are presented on average transverse momenta of charged pions as functions of Feynman- x and the hadronic mass, on the transverse momentum flow within an event and on jet-related quantities. The main features of the data are well described by the LUND model. The data favour a version of the model in which soft gluon effects are included and the primordial transverse momentum of the quarks in the proton is small. Effects from 1st order QCD (hard gluon emission) are negligible.

Single neutral pion production by charged-current ν¯μ interactions on hydrocarbon at 〈Eν〉=3.6 GeV

Directory of Open Access Journals (Sweden)

T. Le

2015-10-01

Full Text Available Single neutral pion production via muon antineutrino charged-current interactions in plastic scintillator (CH is studied using the MINERvA detector exposed to the NuMI low-energy, wideband antineutrino beam at Fermilab. Measurement of this process constrains models of neutral pion production in nuclei, which is important because the neutral-current analog is a background for ν¯e appearance oscillation experiments. The differential cross sections for π0 momentum and production angle, for events with a single observed π0 and no charged pions, are presented and compared to model predictions. These results comprise the first measurement of the π0 kinematics for this process.

Study of Electron Anti-neutrinos Associated with Gamma-Ray Bursts Using KamLAND

Science.gov (United States)

Asakura, K.; Gando, A.; Gando, Y.; Hachiya, T.; Hayashida, S.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Ishikawa, T.; Ishio, S.; Koga, M.; Matsuda, S.; Mitsui, T.; Motoki, D.; Nakamura, K.; Obara, S.; Oki, Y.; Oura, T.; Shimizu, I.; Shirahata, Y.; Shirai, J.; Suzuki, A.; Tachibana, H.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B. D.; Yoshida, H.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Fushimi, K.; Piepke, A.; Banks, T. I.; Berger, B. E.; Fujikawa, B. K.; O'Donnell, T.; Learned, J. G.; Maricic, J.; Sakai, M.; Winslow, L. A.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Decowski, M. P.; KamLAND Collaboration

2015-06-01

We search for electron anti-neutrinos ({{\\bar{ν }}e}) from long- and short-duration gamma-ray bursts (GRBs) using data taken by the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) from 2002 August to 2013 June. No statistically significant excess over the background level is found. We place the tightest upper limits on {{\\bar{ν }}e} fluence from GRBs below 7 MeV and place first constraints on the relation between {{\\bar{ν }}e} luminosity and effective temperature.

Transport, charge exchange and loss of energetic heavy ions in the earth's radiation belts - Applicability and limitations of theory

Science.gov (United States)

Spjeldvik, W. N.

1981-01-01

Computer simulations of processes which control the relative abundances of ions in the trapping regions of geospace are compared with observations from discriminating ion detectors. Energy losses due to Coulomb collisions between ions and exospheric neutrals are considered, along with charge exchange losses and internal charge exchanges. The time evolution of energetic ion fluxes of equatorially mirroring ions under radial diffusion is modelled to include geomagnetic and geoelectric fluctutations. Limits to the validity of diffusion transport theory are discussed, and the simulation is noted to contain provisions for six ionic charge states and the source effect on the radiation belt oxygen ion distributions. Comparisons are made with ion flux data gathered on Explorer 45 and ISEE-1 spacecraft and results indicate that internal charge exchanges cause the radiation belt ion charge state to be independent of source charge rate characteristics, and relative charge state distribution is independent of the radially diffusive transport rate below the charge state redistribution zone.

Anomalies in the Charge Yields of Fission Fragments from the ^{238}U(n,f) Reaction.

Science.gov (United States)

Wilson, J N; Lebois, M; Qi, L; Amador-Celdran, P; Bleuel, D; Briz, J A; Carroll, R; Catford, W; De Witte, H; Doherty, D T; Eloirdi, R; Georgiev, G; Gottardo, A; Goasduff, A; Hadyńska-Klęk, K; Hauschild, K; Hess, H; Ingeberg, V; Konstantinopoulos, T; Ljungvall, J; Lopez-Martens, A; Lorusso, G; Lozeva, R; Lutter, R; Marini, P; Matea, I; Materna, T; Mathieu, L; Oberstedt, A; Oberstedt, S; Panebianco, S; Podolyák, Zs; Porta, A; Regan, P H; Reiter, P; Rezynkina, K; Rose, S J; Sahin, E; Seidlitz, M; Serot, O; Shearman, R; Siebeck, B; Siem, S; Smith, A G; Tveten, G M; Verney, D; Warr, N; Zeiser, F; Zielinska, M

2017-06-02

Fast-neutron-induced fission of ^{238}U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ-γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly.

Observation of Interference in Charge Exchange Scattering in He2++He+ Collisions

International Nuclear Information System (INIS)

Kruedener, S.; Melchert, F.; Diemar, K.v.; Pfeiffer, A.; Huber, K.; Salzborn, E.; Uskov, D.B.; Presnyakov, L.P.

1997-01-01

We report the first observation of interference in charge exchange collisions between two ions. Employing the crossed-beams technique in conjunction with signal recovery methods, angular differential cross sections have been measured for charge transfer in He 2+ +He + collisions at barycentric energies between 0.5 and 10.2keV. The oscillatory structure observed is in agreement with quantum calculations and can be interpreted in terms of interference between scattering into gerade and ungerade molecular states, which arise due to the identity of the nuclear charges. copyright 1997 The American Physical Society

Ion exchange equilibrium for some uni-univalent and uni-divalent reaction systems using strongly basic anion exchange resin Duolite A-102 D

Directory of Open Access Journals (Sweden)

R.S. Lokhande

2008-04-01

Full Text Available The study on thermodynamics of ion exchange equilibrium for uni-univalent Cl-/I-, Cl-/Br-, and uni-divalent Cl-/SO42-, Cl-/C2O42- reaction systems was carried out using ion exchange resin Duolite A-102 D. The equilibrium constant K was calculated by taking into account the activity coefficient of ions both in solution as well as in the resin phase. The K values calculated for uni-univalent and uni-divalent anion exchange reaction systems was observed to increase with rise in temperature, indicating the endothermic exchange reactions having enthalpy values of 13.7, 38.0, 23.9, 22.9 kJ/mol, respectively.

Impact of exact exchange in the description of the electronic structure of organic charge-transfer molecular crystals

KAUST Repository

Fonari, Alexandr

2014-10-21

We evaluate the impact that the amount of nonlocal Hartree-Fock (%HF) exchange included in a hybrid density functional has on the microscopic parameters (transfer integrals, band gaps, bandwidths, and effective masses) describing charge transport in high-mobility organic crystals. We consider both crystals based on a single molecule, such as pentacene, and crystals based on mixed-stack charge-transfer systems, such as dibenzo-TTF–TCNQ. In the pentacene crystal, the band gap decreases and the effective masses increase linearly with an increase in the amount of %HF exchange. In contrast, in the charge-transfer crystals, while the band gap increases linearly, the effective masses vary only slightly with an increase in %HF exchange. We show that the superexchange nature of the electronic couplings in charge-transfer systems is responsible for this peculiar evolution of the effective masses. We compare the density functional theory results with results obtained within the G0W0 approximation as a way of benchmarking the optimal amount of %HF exchange needed in a given functional.

Forging Colloidal Nanostructures via Cation Exchange Reactions.

Science.gov (United States)

De Trizio, Luca; Manna, Liberato

2016-09-28

Among the various postsynthesis treatments of colloidal nanocrystals that have been developed to date, transformations by cation exchange have recently emerged as an extremely versatile tool that has given access to a wide variety of materials and nanostructures. One notable example in this direction is represented by partial cation exchange, by which preformed nanocrystals can be either transformed to alloy nanocrystals or to various types of nanoheterostructures possessing core/shell, segmented, or striped architectures. In this review, we provide an up to date overview of the complex colloidal nanostructures that could be prepared so far by cation exchange. At the same time, the review gives an account of the fundamental thermodynamic and kinetic parameters governing these types of reactions, as they are currently understood, and outlines the main open issues and possible future developments in the field.

Forging Colloidal Nanostructures via Cation Exchange Reactions

Science.gov (United States)

2016-01-01

Among the various postsynthesis treatments of colloidal nanocrystals that have been developed to date, transformations by cation exchange have recently emerged as an extremely versatile tool that has given access to a wide variety of materials and nanostructures. One notable example in this direction is represented by partial cation exchange, by which preformed nanocrystals can be either transformed to alloy nanocrystals or to various types of nanoheterostructures possessing core/shell, segmented, or striped architectures. In this review, we provide an up to date overview of the complex colloidal nanostructures that could be prepared so far by cation exchange. At the same time, the review gives an account of the fundamental thermodynamic and kinetic parameters governing these types of reactions, as they are currently understood, and outlines the main open issues and possible future developments in the field. PMID:26891471

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)

Proton exchange in acid–base complexes induced by reaction coordinates with heavy atom motions

International Nuclear Information System (INIS)

Alavi, Saman; Taghikhani, Mahdi

2012-01-01

Highlights: ► Proton exchange in acid–base complexes is studied. ► The structures, binding energies, and normal mode vibrations are calculated. ► Transition state structures of proton exchange mechanism are determined. ► In the complexes studied, the reaction coordinate involves heavy atom rocking. ► The reaction coordinate is not simply localized in the proton movements. - Abstract: We extend previous work on nitric acid–ammonia and nitric acid–alkylamine complexes to illustrate that proton exchange reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid–strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton exchange transition states are −1 . This contrasts with widely studied proton exchange reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm −1 . Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.

Energy distribution of antineutrinos originating from the decay of fission products in a nuclear reactor

International Nuclear Information System (INIS)

Rudstam, G.; Aleklett, K.

1979-01-01

The energy spectrum of antineutrinos around a nuclear reactor has been derived by summing contributions from individual fission products. The resulting spectrum is weaker at energies above approx. 8 MeV than earlier published antineutrino spectra. The reason may be connected to the strong feeding of high-lying daughter states in the beta decay of fission products with high disintegration energies

Emission of high-energy charged particles at 00 in Ne-induced reactions

International Nuclear Information System (INIS)

Borcea, C.; Gierlik, E.; Kalinin, A.M.; Kalpakchieva, R.; Oganessia, Yu.Ts.; Pawlat, T.; Penionzhkevich, Yu.E.; Ryakhlyuk, A.V.

1982-01-01

Inclusive energy spectra have been measured for light charged particles emitted in the bombardment of 232 Th, 181 Ta, sup(nat)Ti and 12 C targets by 22 Ne ions at 178 MeV and sup(nat)Ti target by 20 Ne ions at 196 MeV. The reaction products were analysed and detected by means of a ΔE-E telescope placed in the focal plane of a magnetic spectrometer located at an angle of 0 deg with respect to the beam direction. In all the reactions studied light charged particles with an energy close to the respective calculated kinematic limit for a two-body exit channel are produced with relatively great probability. The results obtained make it possible to draw some conclusions about the reaction mechanism involving the emission of light charged particles

Charge exchange of hydrogen atoms with multiply charged ions in a hot plasma

International Nuclear Information System (INIS)

Abramov, V.A.; Baryshnikov, F.F.; Lisitsa, V.S.

1980-08-01

The symmetry properties of the hydrogen atom are used to calculate the charge exchange cross-sections sigma of hydrogen with the nuclei of multiply charged ions, allowance being made for the degeneration of final states. If the transitions between these states produced by rotation of the internuclear axis are taken into account, there is a qualitative change in the dependence of sigma on v for low values of v (a gradual decrease in the cross-section instead of the exponential one in the Landau-Zener model) and also a considerable increase in the peak cross-section. The cross-sections are calculated for a wide range of velocities and charge values Z. It is shown that the cross-section may be approximated to within approximately 9 /v).10 -15 cm 2 for Z>=18 (v in cm/s). A detailed comparison with the calculations of various authors is performed. The distribution of final states over orbital angular momenta is found. A calculation is made of variation in the spectral line intensities of the ion O +7 with injection of a neutral hydrogen beam in conditions similar to the experimental conditions on the ORMAK facility. (author)

Diffuse charge and Faradaic reactions in porous electrodes

NARCIS (Netherlands)

Biesheuvel, P.M.; Yu, F.; Bazant, M.Z.

2011-01-01

Porous electrodes instead of flat electrodes are widely used in electrochemical systems to boost storage capacities for ions and electrons, to improve the transport of mass and charge, and to enhance reaction rates. Existing porous electrode theories make a number of simplifying assumptions: (i) The

On the treatment of exchange effects in direct reactions

International Nuclear Information System (INIS)

Bencze, G.; Chandler, C.; Argonne National Lab., IL; New Mexico Univ., Albuquerque

1985-01-01

Exchange effects in direct reactions are investigated in the framework of the general algebraic theory of identical particle scattering. It is shown that effects due to the permutation symmetry of the system can be separated from the treatment of reaction dynamics. Dynamical aspects of the problem are investigated within the framework of the channel coupling class of N-body theories. (orig.)

Use of the TFTR prototype charge exchange neutral analyzer for fast He3++ diagnostics during ICRF heating on PLT

International Nuclear Information System (INIS)

Medley, S.S.

1981-07-01

The Charge Exchange Neutral Analyzer (CENA) for TFTR is designed to measure singly charged ion species of atomic mass A = 1, 2, and 3 simultaneously with up to 75 energy channels per mass and an energy range of 0.5 3 charge exchange neutrals makes the analyzer of particular interest for recently proposed fast He 3 ++ diagnostics during ICRF heating on PLT

The gecko visual pigment: the chromophore dark exchange reaction.

Science.gov (United States)

Crescitelli, F

1988-02-01

This study confirms the occurrence of a dark-exchange reaction in the extracted 521-pigment of the Tokay gecko (G. gekko). The present study involved the exchange, in the dark, of the natural 11-cis-chromophore by the 9-cis-10-F-retinal analog. This analog is able to combine with the 521-opsin to regenerate a photopigment at 492 nm. In addition to this shift in absorbance from 521 to 492 nm, the analog photopigment has a photosensitivity some 2.4% that of the native 521-system in the chloride-sufficient state. These two properties of the regenerated analog pigment have simplified the demonstration of a dark exchange of chromophores. At 15 degrees C the 9-cis-10-F-analog replaces the 11-cis-chromophore by at least 30% (density-wise) in about 15 hr. This exchange occurs with the system in the chloride-deficient state. The presence of chloride during the period in the dark significantly reduces the magnitude of the exchange. Apparently, the protein has a more open structure at the chromophoric binding site, allowing this interchange of chromophores. The addition of chloride induces a conformational change at this site, 'burying' the Schiff base and reducing the exchange reaction. The biological implication of this mobile property of the gecko opsin is that it is similar to the behavior of the cone pigment iodopsin but is unlike that of rhodopsins. This supports the idea that the gecko visual cells, despite their appearance as rods, are phylogenetically related to ancestral photopic receptors.

Charge exchange in low-energy Li/sup 3 +/-H collisions

Energy Technology Data Exchange (ETDEWEB)

Casaubon, J I [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina); Piacentini, R D [Rosario Univ. Nacional (Argentina). Dept. de Fisica; Observatorio Astronomico Municipal, Rosario (Argentina)); Salin, A [Bordeaux-1 Univ., 33 - Talence (France)

1981-04-28

The charge exchange between a completely stripped lithium ion and a hydrogen atom is studied in the framework of the impact parameter molecular approximation for relative velocities lower than one atomic unit. The total cross section shows a strong increase as a function of the energy. The results are compared with theoretical and experimental data of other authors.

The energy dependence of neutron-proton charge exchange

International Nuclear Information System (INIS)

Bouquet, A.; Diu, R.

1978-01-01

The new Fermilab data on up charge exchange are analysed phenomenologically, to determine the energy dependence of the amplitudes in the corresponding domain (60 2 trajectories. If one imposes the presence of standard rho-A 2 terms (three-component analysis), one has to introduce a pomeronlike contribution, with a trajectory α approximately equal to 1.0+0.25t. In both cases, the resulting parametrization gives a good description of the data from Psub(lab)=1GeV/c up to 300GeV/c

Direct spectroscopic observation of charge-exchange recombination of medium-Z elements in the PLT tokamak

International Nuclear Information System (INIS)

Skinner, C.H.; Suckewer, S.; Cohen, S.A.; Schilling, G.; Wilson, R.; Stratton, B.

1984-03-01

We report the first observation of line emission resulting directly from charge-exchange recombination of medium-Z elements (Al, Sc) injected into a PLT discharge. Transitions due to the radiative cascade immediately following charge-exchange of He-like Al and Sc were observed by a VUV spectrograph and two air monochromators. In two cases, AlXI 3209 A and ScXIX 112.1 A, the observed transition had not previously been experimentally identified. Spatial scans provided information on the profile of the neutral beam in the plasma

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....

Theoretical investigation of isotope exchange reaction in tritium-contaminated mineral oil in vacuum pump.

Science.gov (United States)

Dong, Liang; Xie, Yun; Du, Liang; Li, Weiyi; Tan, Zhaoyi

2015-04-28

The mechanism of the isotope exchange reaction between molecular tritium and several typical organic molecules in vacuum pump mineral oil has been investigated by density functional theory (DFT), and the reaction rates are determined by conventional transition state theory (TST). The tritium-hydrogen isotope exchange reaction can proceed with two different mechanisms, the direct T-H exchange mechanism and the hyrogenation-dehydrogenation exchange mechanism. In the direct exchange mechanism, the titrated product is obtained through one-step via a four-membered ring hydrogen migration transition state. In the hyrogenation-dehydrogenation exchange mechanism, the T-H exchange could be accomplished by the hydrogenation of the unsaturated bond with tritium followed by the dehydrogenation of HT. Isotope exchange between hydrogen and tritium is selective, and oil containing molecules with OH and COOH groups can more easily exchange hydrogen for tritium. For aldehydes and ketones, the ability of T-H isotope exchange can be determined by the hydrogenation of T2 or the dehydrogenation of HT. The molecules containing one type of hydrogen provide a single product, while the molecules containing different types of hydrogens provide competitive products. The rate constants are presented to quantitatively estimate the selectivity of the products. Copyright © 2015 Elsevier B.V. All rights reserved.

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.;

Nucleophilic radioiodination of 6-bromocholesterol via non-isotopic exchange reaction in molten state

International Nuclear Information System (INIS)

El-Shaboury, G.; Farah, K.; El-Tawoosy, M.

2001-01-01

A synthetic method for preparing radioiodinated 6-[ 125 I]iodocholesterol [CL-6- 125 I] for adrenal evaluation is described. The radioiodine atom was incorporated onto the cholesterol molecule via non-isotopic exchange between 6-bromocholesterol [CL-6-Br] and radioiodine as iodide ion [ 125 I - ] in a molten state. The different parameters affecting the yield of exchange were investigated using 125 I (T 1/2 ≅ 60 d) to centralize the different physical and chemical reaction conditions and purification of the final product as pure as 6-[ 125 I]iodocholesterol. The method was suitable to either 131 I (T 1/2 ≅ 8 d) nucleophilic radioiodination which facilitates the scanning of the adrenal for a few days after administration or the use of 124 I (T 1/2 ≅ 4.16 d) nucleophilic radioiodination for PET evaluation of the adrenal. TLC as well as HPLC chromatographic analysis is used to determine the efficiency of the exchange reactions under different chemical reaction conditions and to monitor the stability of the final product as pure as CL-6- 125 I with radiochemical purity of ≅99%. This no-carrier-added method improved the speed of the reaction and affords high radiochemical yield of 90% and suitable specific activity due to the use of CL-6-Br rather than CL-6-I as substrate. Kinetic studies revealed second order iodine-bromine exchange reaction. The activation energy for the exchange reaction in ammonium acetate (m.p. 114 deg C) was calculated to be 4.576 kcal/mole. (author)

Development of an advanced antineutrino detector for reactor monitoring

Energy Technology Data Exchange (ETDEWEB)

Classen, T., E-mail: classen2@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Bernstein, A.; Bowden, N.S. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Cabrera-Palmer, B. [Sandia Livermore National Laboratories, Livermore, CA 94550 (United States); Ho, A.; Jonkmans, G. [Atomic Energy of Canada, Limited, Chalk River Laboratories, Chalk River, ON (Canada); Kogler, L.; Reyna, D. [Sandia Livermore National Laboratories, Livermore, CA 94550 (United States); Sur, B. [Atomic Energy of Canada, Limited, Chalk River Laboratories, Chalk River, ON (Canada)

2015-01-21

Here we present the development of a compact antineutrino detector for the purpose of nuclear reactor monitoring, improving upon a previously successful design. This paper will describe the design improvements of the detector which increases the antineutrino detection efficiency threefold over the previous effort. There are two main design improvements over previous generations of detectors for nuclear reactor monitoring: dual-ended optical readout and single volume detection mass. The dual-ended optical readout eliminates the need for fiducialization and increases the uniformity of the detector's optical response. The containment of the detection mass in a single active volume provides more target mass per detector footprint, a key design criteria for operating within a nuclear power plant. This technology could allow for real-time monitoring of the evolution of a nuclear reactor core, independent of reactor operator declarations of fuel inventories, and may be of interest to the safeguards community.

Gamow-Teller Strengths from (3He,t) Charge-Exchange Reaction

International Nuclear Information System (INIS)

Fujita, Yoshitaka

2006-01-01

Gamow-Teller (GT) transition is the most popular nuclear weak process with the nature of spin-isospin excitation. GT transitions in pf-shell nuclei, including those starting from unstable nuclei, are of interest, due to their importance in astrophysical processes. Weak processes, however, gives us rather limited information on the GT response of nuclei. We introduce high-resolution ( 3 He, t) reaction at 0 0 and at an intermediate beam energy as a new spectroscopic tool for studying GT excitations. Owing to the high energy-resolution of the reaction (∼ 30 keV), individual transitions can be observed up to the region of GT giant resonance. Assuming isospin symmetry for the T z = ±1 → 0 isobaric analogous transitions in isobars with mass number A, we present a new method to deduce GT transition strengths starting from proton rich exotic nuclei

Charged-particle induced thermonuclear reaction rates: a compilation for astrophysics

International Nuclear Information System (INIS)

Grama, Cornelia; Angulo, C.; Arnould, M.

2000-01-01

The rapidly growing wealth of nuclear data becomes less and less easily accessible to the astrophysics community. Mastering this volume of information and making it available in an accurate and usable form for incorporation into stellar evolution or nucleosynthesis models become urgent goals of prime necessity. we report on the results of the European network NACRE (Nuclear Astrophysics Compilation of REaction rates). The principal motivation for the setting-up of the NACRE network has been the necessity of building up a well-documented and detailed compilation of rates for charged-particle induced reactions on stable targets up to Si and on unstable nuclei of special significance in astrophysics. This work is meant to supersede the only existing compilation of reaction rates issued by Fowler and collaborators. The cross section data and/or resonance parameters for a total of 86 charged-particle induced reactions are given and the corresponding reaction rates are calculated and given in tabular form. When cross section data are not available in the whole needed range of energies, the theoretical predictions obtained in the framework of the Hauser-Feshbach model is used. Uncertainties are analyzed and realistic upper and lower bounds of the rates are determined. Reverse reaction rates and analytical approximations of the adopted rates are also provided. (authors)

Charged-particle induced thermonuclear reaction rates: a compilation for astrophysics

International Nuclear Information System (INIS)

Grama, Cornelia

1999-01-01

The rapidly growing wealth of nuclear data becomes less and less easily accessible to the astrophysics community. Mastering this volume of information and making it available in an accurate and usable form for incorporation into stellar evolution or nucleosynthesis models become urgent goals of prime necessity. We report on the results of the European network NACRE (Nuclear Astrophysics Compilation of REaction rates). The principal motivation for the setting-up of the NACRE network has been the necessity of building up a well-documented and detailed compilation of rates for charged -particle induced reactions on stable targets up to Si and on unstable nuclei of special significance in astrophysics. This work is meant to supersede the only existing compilation of reaction rates issued by Fowler and collaborators. The cross section data and/or resonance parameters for a total of 86 charged-particle induced reactions are given and the corresponding reaction rates are calculated and given in tabular form. When cross section data are not available in the whole needed range of energies the theoretical predictions obtained in the framework of the Hauser-Feshbach model are used. Uncertainties are analyzed and realistic upper and lower bounds of the rates are determined. Reverse reaction rates and analytical approximations of the adopted rates are also provided. (author)

Carbonyl-Olefin Exchange Reaction: Present State and Outlook

Science.gov (United States)

Kalinova, Radostina; Jossifov, Christo

The carbonyl-olefin exchange reaction (COER) is a new reaction between carbonyl group and olefin double bond, which has a formal similarity with the olefin metathesis (OM) - one carbon atom in the latter is replaced with an oxygen atom. Till now the new reaction is performed successfully only when the two functional groups (carbonyl group and olefin double bond) are in one molecule and are conjugated. The α, β-unsaturated carbonyl compounds (substituted propenones) are the compounds with such a structure. They polymerize giving substituted polyacetylenes. The chain propagation step of this polymerization is in fact the COER. The question arises: is it possible the COER to take place when the two functional groups are not in one molecule and are not conjugated, and could this reaction became an alternative of the existing carbonyl olefination reactions?

Study of transverse momenta of charged hadrons produced in νp and anti νp charged current interactions

International Nuclear Information System (INIS)

Jones, G.T.; Kennedy, B.W.; Middleton, R.P.; O'Neale, S.W.; Cooper, A.M.; Grant, A.; Klein, H.; Mittendorfer, J.; Morrison, D.R.O.; Parker, A.; Schmid, P.; Wachsmuth, H.; Hamisi, F.; Mobayyen, M.M.; Villalobos-Baillie, O.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radiojicic, D.; Retter, M.

1984-01-01

Data from a neutrino and antineutrino hydrogen experiment with BEBC are used to investigate transverse properties of the produced charged hadrons. Measurements are presented on average transverse momenta of charged pions as functions of Feynman-x and the hadronic mass, on the transverse momentum flow within an event and on jet-related quantities. The main features of the data are well described by the LUND model. The data favour a version of the model in which soft gluon effects are included and the primordial transverse momentum of the quarks in the proton is small. Effects from 1st order QCD (hard gluon emission) are negligible. (orig.)

Study of transverse momenta of charged hadrons produced in νp and anti νp charged current interactions

International Nuclear Information System (INIS)

Jones, G.T.; Kennedy, B.W.; Middleton, R.P.; O'Neale, S.W.; Cooper, A.M.; Grant, A.; Klein, H.; Mittendorfer, J.; Morrison, D.R.O.; Parker, A.; Schmid, P.; Wachsmuth, H.; Hamisi, F.; Mobayyen, M.M.; Villalobos-Baillie, O.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Retter, M.

1984-05-01

Data from neutrino and antineutrino hydrogen experiment with BEBC are used to investigate transverse properties of the produced charged hadrons. Measurements are presented on average transverse momenta of charged pions as functions of Feynman-x and the hadronic mass, on the transverse momentum flow within an event and on jet-related quantities. The main features of the data are well described by the LUND model. The data favour a version of the model in which soft gluon effects are included and the primordial transverse momentum of the quarks in the proton is small. Effects from 1st order QCD (hard gluon emission) are negligible. (orig.)

The double chooz experiment: simulation of reactor antineutrino spectra

International Nuclear Information System (INIS)

Mueller, T.

2010-01-01

The Double Chooz experiment aims to study the oscillations of electron antineutrinos produced by the Chooz nuclear power station, located in France, in the Ardennes region. It will lead to an unprecedented accuracy on the value of the mixing angle θ 13 . Improving the current knowledge on this parameter, given by the Chooz experiment, requires a reduction of both statistical and systematic errors, that is to say not only observing a large data sample, but also controlling the experimental uncertainties involved in the production and detection of electron antineutrinos. The use of two identical detectors will cancel most of the experimental systematic uncertainties limiting the sensitivity to the value of the mixing angle. We present in this thesis, simulations of reactor antineutrino spectra that were carried out in order to control the sources of systematic uncertainty related to the production of these particles by the plant. We also discuss our work on controlling the normalization error of the experiment through the precise determination of the number of target protons by a weighing measurement and through the study of the fiducial volume of the detectors which requires an accurate modeling of neutron physics. After three years of data taking with two detectors, Double Chooz will be able to disentangle an oscillation signal for sin 2 2θ 13 ≥ 0.05 (at 3σ) or, if no oscillations are observed, to put a limit of sin 2 2θ 13 ≤ 0.03 at 90% C.L. (author) [fr

Calculation of the cross section of the H2+(D2+)+Li→Li++2H(2D) charge-exchange reaction

International Nuclear Information System (INIS)

Voronin, A.I.; Osherov, V.I.; Poluyanov, L.V.; Ushakov, V.G.

1983-01-01

The method of classic trajectories with account for non-adiabatic transitions has been used to calculate Li atoms charge-exchange cross sections on H 2 + and D 2 + ions depending on collision energy and oscillatory excitation of molecular ion. Surfaces of potentil energy of nuclei interaction corresponding to essential for the chargeexchange process electron states are plotted by the diatomics-in-molecules (DIM) method. Qualitative characteristics of calculated cross sections (dependence on collision energy, oscillatory number, deuteration effect) coincide well with those obtained during the experiment. However the experimental cross section value approximately two times surpasses the theoretical one. This is connected with insufficient accuracy of the DIM method

Solar wind/local interstellar medium interaction including charge exchange with neural hydrogen

Science.gov (United States)

Pauls, H. Louis; Zank, Gary P.

1995-01-01

We present results from a hydrodynamic model of the interaction of the solar wind with the local interstellar medium (LISM), self-consistently taking into account the effects of charge exchange between the plasma component and the interstellar neutrals. The simulation is fully time dependent, and is carried out in two or three dimensions, depending on whether the helio-latitudinal dependence of the solar wind speed and number density (both giving rise to three dimensional effects) are included. As a first approximation it is assumed that the neutral component of the flow can be described by a single, isotropic fluid. Clearly, this is not the actual situation, since charge exchange with the supersonic solar wind plasma in the region of the nose results in a 'second' neutral fluid propagating in the opposite direction as that of the LISM neutrals.

Current status of uranium enrichment by way of chemical exchange reactions

International Nuclear Information System (INIS)

El Basyouny, A.; Bechthold, H.C.; Knoechel, A.; Vollmer, H.J.

1985-04-01

For this report, conference proceedings, patents and other types of literature have been collected to present an account of the current status of uranium enrichment by way of chemical exchange reactions. The report further presents a new concept along with the relevant process strategy developed by the authors. The principal process of the new concept is a chemical exchange process with crown ethers, complexed or free, playing an important part in the reactions. The authors also describe their experiments carried out for establishing suitable chemical systems. (orig./PW) [de

Exchange reactions in the systems of alkali metal, silver and thallium, sulfates, niobates and tantalates

International Nuclear Information System (INIS)

Belyaev, I.N.; Lupejko, T.G.; Nalbandyan, V.B.; Abanina, E.V.

1978-01-01

Investigated are exchange interactions in diagonal cross sections of twenty triple mutual systems with A and A' cations and SO 4 and MO 3 anions where A and A'-Li, Na, K, Ag, Tl, M-Nb, Ta using the methods of X-ray phase, chemical and differential thermal analyses. Exchange reaction between crystal complex oxide and melted salt are effective synthesis method. These reactions in particular permitted to obtain pure AgNbO 3 , AgTaO 3 and their solid solutions at temperatures hundreds degrees lower than in displacement reactions. Equilibrium samples of AMO 3 -A'MO 3 systems, continuous or discontinuous solid solutions, compounds (except NaMO 3 -KMO 3 , and also LiTaO 3 -KTaO 3 ) are formed in exchange reactions when there is sulfate shortage. Thus, exchange reactions can be applied for solid solution synthesis, and also for phase diagram study

Hydrogen and oxygen isotope exchange reactions over illuminated and nonilluminated TiO2

International Nuclear Information System (INIS)

Sato, S.

1987-01-01

Hydrogen isotope exchange between H 2 , gaseous H 2 O, and the surface hydroxyls of TiO 2 , and oxygen isotope exchange between O 2 , CO 2 , CO, H 2 O vapor, and the hydroxyls over TiO 3 were studied at room temperature in the dark and under illumination. Hydrogen isotope exchange between H 2 O and the hydroxyls occurred rapidly in the dark, but the exchange involving H 2 did not occur at all even under illumination. Oxygen isotope exchange among H 2 O vapor, CO 2 , and the hydroxyls easily took place in the dark, but the exchange involving O 2 required band-gap illumination. Dioxygen isotope equilibration was much faster than the other photoexchange reactions. Although the oxygen exchange between O 2 and illuminated TiO 2 has been considered to involve lattice-oxygen exchange, the present experiments revealed that the hydroxyls of TiO 2 mainly participate in the exchange reaction. The oxygen exchange between O 2 and H 2 O vapor was strongly inhibited by H 2 O vapor itself probably because oxygen adsorption was retarded by adsorbed water. Oxygen in CO was not exchanged with the other substrates under any conditions tested

Development of utility system of charged particle Nuclear Reaction Data on Unified Interface

International Nuclear Information System (INIS)

Aoyama, Shigeyoshi; Ohbayashi, Yosihide; Kato, Kiyoshi; Masui, Hiroshi; Ohnishi, Akira; Chiba, Masaki

1999-01-01

We have developed a utility system, WinNRDF, for a nuclear charged particle reaction data of NRDF (Nuclear Reaction Data File) on a unified interface of Windows95, 98/NT. By using the system, we can easily search the experimental data of a charged particle reaction in NRDF and also see the graphic data on GUI (Graphical User Interface). Furthermore, we develop a mechanism of making a new index of keywords in order to include the time developing character of the NRDF database. (author)

Theoretical investigation of isotope exchange reaction in tritium-contaminated mineral oil in vacuum pump

Energy Technology Data Exchange (ETDEWEB)

Dong, Liang; Xie, Yun [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Du, Liang [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); School of Radiation Medicine and Protection (SRMP), School for Radiological and Interdisciplinary Sciences (RAD-X), Suzhou 215000 (China); Li, Weiyi [School of Physics and Chemistry, Xihua University, Chengdu 610065 (China); Tan, Zhaoyi, E-mail: zhyitan@126.com [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China)

2015-04-28

Highlights: • This is the first theoretical investigation about T–H exchange in vacuum oil. • T–H isotope exchange is accomplished through two different change mechanisms. • Isotope exchange is selective, molecules with −OH and −COOH exchange more easily. • The methyl and methylene radicals in waste oil were observed by {sup 1}HNMR. - Abstract: The mechanism of the isotope exchange reaction between molecular tritium and several typical organic molecules in vacuum pump mineral oil has been investigated by density functional theory (DFT), and the reaction rates are determined by conventional transition state theory (TST). The tritium–hydrogen isotope exchange reaction can proceed with two different mechanisms, the direct T–H exchange mechanism and the hyrogenation–dehydrogenation exchange mechanism. In the direct exchange mechanism, the titrated product is obtained through one-step via a four-membered ring hydrogen migration transition state. In the hyrogenation–dehydrogenation exchange mechanism, the T–H exchange could be accomplished by the hydrogenation of the unsaturated bond with tritium followed by the dehydrogenation of HT. Isotope exchange between hydrogen and tritium is selective, and oil containing molecules with −OH and −COOH groups can more easily exchange hydrogen for tritium. For aldehydes and ketones, the ability of T–H isotope exchange can be determined by the hydrogenation of T{sub 2} or the dehydrogenation of HT. The molecules containing one type of hydrogen provide a single product, while the molecules containing different types of hydrogens provide competitive products. The rate constants are presented to quantitatively estimate the selectivity of the products.

Exchange reaction of acetylene-d2 with hydrogen chloride

International Nuclear Information System (INIS)

Bopp, A.F.; Kern, R.D.

1975-01-01

A mixture containing 3 percent each of the reactants C 2 D 2 and HCl in an Ne--Ar diluent was studied over the temperature range 1650 to 2600 0 K utilizing a shock tube coupled to a time-of-flight mass spectrometer. Plots of the mole fractions f of the exchange products, DCl and C 2 HD, revealed two distinct regions of growth: (a) an initial low conversion region characterized by an induction period t/sub i/; and (b) a region of accelerated exchange during which exchange products were formed with a quadratic dependence of the reaction time. These two regions labeled a and b were combined using two empirical equations, 1 - f/sub a//f/sub eq,a/ = exp [-k/sub a/[M]t], where t less than or equal to t/sub i/, and 1 - f/sub b//f/sub eq,b/ = exp [-k/sub b/[M](t - t/sub i/) 2 ], in order to represent the entire reaction profile at any given temperature within the interval investigated. The Arrhenius parameters for k/sub a/ and k/sub b/ were determined to be 10 11 . 15+-0 . 30 exp (-19990 +- 2850/RT) and 10 16 . 40+-0 . 41 exp (-31480 +- 4200/RT), respectively, for DCl and 10 11 . 69+-0 . 29 exp (-19150 +- 2740/RT) and 10 15 . 24+-0 . 34 exp (-17620 +- 3480/RT) for C 2 HD. The units for k/sub a/ are cm 3 mol -1 sec -1 and cm 3 mol -1 sec -2 for k/sub b/. Activation energies are reported in cal mol -1 . Comparison with the profiles obtained for acetylene pyrolysis strongly suggests that the mechanism for the exchange is atomic. Furthermore, the exchange experiments indicate that the initial step in the pyrolysis of acetylene is the disproportionation reaction, 2C 2 H 2 → C 2 H + C 2 H 3

Charged particle induced thermonuclear reaction rates: a compilation for astrophysics

International Nuclear Information System (INIS)

Grama, C.

1999-01-01

We report on the results of the European network NACRE (Nuclear Astrophysics Compilation of REaction rates). The principal reason for setting up the NACRE network has been the necessity of building up a well-documented and detailed compilation of rates for charged-particle induced reactions on stable targets up to Si and on unstable nuclei of special significance in astrophysics. This work is meant to supersede the only existing compilation of reaction rates issued by Fowler and collaborators. The main goal of NACRE network was the transparency in the procedure of calculating the rates. More specifically this compilation aims at: 1. updating the experimental and theoretical data; 2. distinctly identifying the sources of the data used in rate calculation; 3. evaluating the uncertainties and errors; 4. providing numerically integrated reaction rates; 5. providing reverse reaction rates and analytical approximations of the adopted rates. The cross section data and/or resonance parameters for a total of 86 charged-particle induced reactions are given and the corresponding reaction rates are calculated and given in tabular form. Uncertainties are analyzed and realistic upper and lower bounds of the rates are determined. The compilation is concerned with the reaction rates that are large enough for the target lifetimes shorter than the age of the Universe, taken equal to 15 x 10 9 y. The reaction rates are provided for temperatures lower than T = 10 10 K. In parallel with the rate compilation a cross section data base has been created and located at the site http://pntpm.ulb.ac.be/nacre..htm. (authors)